Bump version

Add apply demurrage cli tool

See merge request cicnet/erc20-demurrage-token!9

.gitignore

@@ -6,3 +6,5 @@ __pycache__
 gmon.out
 solidity/*.json
 solidity/*.bin
+.venv
+venv

.gitlab-ci.yml

@@ -0,0 +1,36 @@
+# To contribute improvements to CI/CD templates, please follow the Development guide at:
+# https://docs.gitlab.com/ee/development/cicd/templates.html
+# This specific template is located at:
+# https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Python.gitlab-ci.yml
+
+# Official language image. Look for the different tagged releases at:
+# https://hub.docker.com/r/library/python/tags/
+image: python:3.8
+
+# Change pip's cache directory to be inside the project directory since we can
+# only cache local items.
+variables:
+  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+
+# Pip's cache doesn't store the python packages
+# https://pip.pypa.io/en/stable/reference/pip_install/#caching
+#
+# If you want to also cache the installed packages, you have to install
+# them in a virtualenv and cache it as well.
+cache:
+  paths:
+    - .cache/pip
+    - venv/
+
+before_script:
+  - cd ./python
+  - python --version  # For debugging
+  - pip install virtualenv
+  - virtualenv venv
+  - source venv/bin/activate
+
+test:
+  script:
+    - pip install -r requirements.txt -r test_requirements.txt --extra-index-url https://pip.grassrootseconomics.net
+    - bash run_tests.sh 
+

README.md

@@ -1,5 +1,7 @@
 # RedistributedDemurrageToken
 
+**this documentation is obsolete, will rewrite asap**
+
 ## Use Case
 * Network / Basic Income Token
   * 100 Sarafu is distributed to anyone in Kenya after user validation by the owner of a faucet which mints new Sarafu.

python/CHANGELOG

@@ -0,0 +1,21 @@
+- 0.3.0
+	* Smart contracts use abdk math libraries, all exponential operations are static gas cost
+	* Add expiry features, after which balances are frozen and no more transfers or demurrage will occur
+	* Add sealable features for supply, sink address, expiry and minters (when sealed cannot be changed)
+	* Deployer script now takes demurrage amount as ppm instead of literal growth fraction
+	* Retire old multi and cap contracts
+	* Replace contract bitfields for redistributions with structs
+- 0.1.1
+	* Settable demurrage steps for apply demurrage cli tool
+- 0.1.0
+	* Dependency upgrades
+- 0.0.11
+	* Apply demurrage cli tool
+- 0.0.10
+	* Settable sink address
+- 0.0.9
+	* Correct redistribution amount for SingleNocap contract
+- 0.0.2
+	* Move to chainlib-eth
+- 0.0.1
+	* Interface for redistributed and non-redistributed, with or without cap

python/MANIFEST.in

@@ -1 +1 @@
-include sarafu_token/data/*
+include erc20_demurrage_token/data/* erc20_demurrage_token/data/config/*.ini *requirements.txt

python/erc20_demurrage_token/__init__.py

@@ -1,4 +1,5 @@
 from .token import (
         DemurrageToken,
         DemurrageTokenSettings,
+        DemurrageRedistribution,
         )

python/erc20_demurrage_token/data/config/eth.ini

@@ -0,0 +1,2 @@
+[eth]
+provider=http://localhost:8545

python/erc20_demurrage_token/data/config/session.ini

@@ -0,0 +1,2 @@
+[session]
+chain_spec=

python/erc20_demurrage_token/data/config/token.ini

@@ -0,0 +1,8 @@
+[token]
+redistribution_period=10800
+demurrage_level=50
+supply_limit=0
+symbol=RDT
+name=Redistributed Demurraged Token
+decimals=6
+sink_address=

python/erc20_demurrage_token/demurrage.py

@@ -0,0 +1,67 @@
+# standard imports
+import logging
+import datetime
+import math
+
+# eternal imports
+from chainlib.eth.constant import ZERO_ADDRESS
+
+# local imports
+from .token import DemurrageToken
+
+logg = logging.getLogger(__name__)
+
+
+class DemurrageCalculator:
+
+    def __init__(self, interest_f_minute):
+
+        self.r_min = interest_f_minute
+        self.r_hour = 1 - ((1 -self.r_min) ** 60)
+        self.r_day = 1 - ((1 -self.r_hour) ** 24)
+        #self.r_week = interest_f_day ** 7
+        logg.info('demurrage calculator set with min {:.32f} hour {:.32f} day {:.32f}'.format(self.r_min, self.r_hour, self.r_day))
+
+
+    def amount_since(self, amount, timestamp):
+        delta = datetime.datetime.utcnow() - datetime.datetime.fromtimestamp(timestamp)
+        adjusted_amount = amount * ((1 - self.r_day) ** (delta.days))
+        logg.debug('adjusted for {} days {} -> {}'.format(delta.days, amount, adjusted_amount))
+
+        remainder = delta.seconds
+        remainder_hours = math.floor(remainder / (60 * 60))
+        adjusted_delta = adjusted_amount * ((1 - self.r_hour) ** remainder_hours)
+        adjusted_amount -= (adjusted_amount - adjusted_delta)
+        logg.debug('adjusted for {} hours {} -> {} delta {}'.format(remainder_hours, amount, adjusted_amount, adjusted_delta))
+
+        remainder -= (remainder_hours * (60 * 60))
+        remainder_minutes = math.floor(remainder / 60)
+        adjusted_delta = adjusted_amount * ((1 - self.r_min) ** remainder_minutes)
+        adjusted_amount -= (adjusted_amount - adjusted_delta)
+        logg.debug('adjusted for {} minutes {} -> {} delta {}'.format(remainder_minutes, amount, adjusted_amount, adjusted_delta))
+
+        return adjusted_amount
+
+    
+    def amount_since_slow(self, amount, timestamp):
+        delta = datetime.datetime.utcnow() - datetime.datetime.fromtimestamp(timestamp)
+        remainder_minutes = math.floor(delta.total_seconds() / 60)
+        adjusted_amount = amount * ((1 - self.r_min) ** remainder_minutes)
+        logg.debug('adjusted for {} minutes {} -> {} delta {}'.format(remainder_minutes, amount, adjusted_amount, amount - adjusted_amount))
+
+        return adjusted_amount
+
+
+    @staticmethod
+    def from_contract(rpc, chain_spec, contract_address, sender_address=ZERO_ADDRESS):
+        c = DemurrageToken(chain_spec)
+        o = c.tax_level(contract_address, sender_address=sender_address)
+        r = rpc.do(o)
+        taxlevel_i = c.parse_tax_level(r)
+
+        o = c.resolution_factor(contract_address, sender_address=sender_address)
+        r = rpc.do(o)
+        divider = c.parse_resolution_factor(r)
+        logg.debug('taxlevel {} f {}'.format(taxlevel_i, divider))
+        taxlevel_f = taxlevel_i / divider
+        return DemurrageCalculator(taxlevel_f)

python/erc20_demurrage_token/expiry.py

@@ -0,0 +1,36 @@
+# external imports
+from chainlib.eth.tx import (
+        TxFactory,
+        TxFormat,
+        )
+from chainlib.eth.contract import (
+        ABIContractEncoder,
+        ABIContractType,
+        abi_decode_single,
+        )
+from chainlib.eth.constant import ZERO_ADDRESS
+
+
+class ExpiryContract(TxFactory):
+
+    def set_expire_period(self, contract_address, sender_address, expire_timestamp, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('setExpirePeriod')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(expire_timestamp)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
+    def expires(self, contract_address, sender_address=ZERO_ADDRESS):
+        return self.call_noarg('expires', contract_address, sender_address=sender_address)
+
+
+    @classmethod
+    def parse_expires(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+

python/erc20_demurrage_token/runnable/deploy.py

@@ -12,9 +12,10 @@ import json
 import argparse
 import logging
 
-# third-party imports
-from crypto_dev_signer.eth.signer import ReferenceSigner as EIP155Signer
-from crypto_dev_signer.keystore.dict import DictKeystore
+# external imports
+import confini
+from funga.eth.signer import EIP155Signer
+from funga.eth.keystore.dict import DictKeystore
 from chainlib.chain import ChainSpec
 from chainlib.eth.nonce import (
         RPCNonceOracle,
@@ -27,99 +28,135 @@ from chainlib.eth.gas import (
 from chainlib.eth.connection import EthHTTPConnection
 from chainlib.eth.tx import receipt
 from chainlib.eth.constant import ZERO_ADDRESS
+import chainlib.eth.cli
+from chainlib.eth.cli.arg import (
+        Arg,
+        ArgFlag,
+        process_args,
+        )
+from chainlib.eth.cli.config import (
+        Config,
+        process_config,
+        )
+from chainlib.eth.cli.log import process_log
+from chainlib.eth.settings import process_settings
+from chainlib.eth.address import to_checksum_address
+from chainlib.settings import ChainSettings
+
+from dexif import to_fixed
 
 # local imports
-from erc20_demurrage_token import DemurrageToken
+import erc20_demurrage_token
+from erc20_demurrage_token import (
+        DemurrageToken,
+        DemurrageTokenSettings,
+        )
 
-logging.basicConfig(level=logging.WARNING)
 logg = logging.getLogger()
 
 script_dir = os.path.dirname(__file__)
 data_dir = os.path.join(script_dir, '..', 'data')
 
-argparser = argparse.ArgumentParser()
-argparser.add_argument('-p', '--provider', dest='p', default='http://localhost:8545', type=str, help='Web3 provider url (http only)')
-argparser.add_argument('-w', action='store_true', help='Wait for the last transaction to be confirmed')
-argparser.add_argument('-ww', action='store_true', help='Wait for every transaction to be confirmed')
-argparser.add_argument('-i', '--chain-spec', dest='i', type=str, default='evm:ethereum:1', help='Chain specification string')
-argparser.add_argument('-y', '--key-file', dest='y', type=str, help='Ethereum keystore file to use for signing')
-argparser.add_argument('-v', action='store_true', help='Be verbose')
-argparser.add_argument('-vv', action='store_true', help='Be more verbose')
-argparser.add_argument('-d', action='store_true', help='Dump RPC calls to terminal and do not send')
-argparser.add_argument('--name', type=str, help='Token name')
-argparser.add_argument('--decimals', default=6, type=int, help='Token decimals')
-argparser.add_argument('--gas-price', type=int, dest='gas_price', help='Override gas price')
-argparser.add_argument('--nonce', type=int, help='Override transaction nonce')
-argparser.add_argument('--sink-address', default=ZERO_ADDRESS, type=str, help='demurrage level,ppm per minute') 
-argparser.add_argument('--redistribution-period', default=10080, type=int, help='redistribution period, minutes') # default 10080 = week
-argparser.add_argument('--env-prefix', default=os.environ.get('CONFINI_ENV_PREFIX'), dest='env_prefix', type=str, help='environment prefix for variables to overwrite configuration')
-argparser.add_argument('symbol', default='SRF', type=str, help='Token symbol')
-argparser.add_argument('demurrage_level', type=int, help='demurrage level, ppm per minute') 
+config_dir = os.path.join(data_dir, 'config')
+
+
+def process_config_local(config, arg, args, flags):
+    config.add(args.token_name, 'TOKEN_NAME')
+    config.add(args.token_symbol, 'TOKEN_SYMBOL')
+    config.add(args.token_decimals, 'TOKEN_DECIMALS')
+    sink_address = to_checksum_address(args.sink_address)
+    config.add(sink_address, 'TOKEN_SINK_ADDRESS')
+    config.add(args.redistribution_period, 'TOKEN_REDISTRIBUTION_PERIOD')
+
+    v = args.demurrage_level / 1000000
+    if v >= 1.0:
+        raise ValueError('demurrage level must be less than 100%')
+    demurrage_level = to_fixed(v)
+    config.add(demurrage_level, 'TOKEN_DEMURRAGE_LEVEL')
+    return config
+
+
+arg_flags = ArgFlag()
+arg = Arg(arg_flags)
+flags = arg_flags.STD_WRITE | arg_flags.WALLET
+
+argparser = chainlib.eth.cli.ArgumentParser(arg_flags)
+argparser = process_args(argparser, arg, flags)
+argparser.add_argument('--name', dest='token_name', type=str, help='Token name')
+argparser.add_argument('--symbol', dest='token_symbol', required=True, type=str, help='Token symbol')
+argparser.add_argument('--decimals', dest='token_decimals', type=int, help='Token decimals')
+argparser.add_argument('--sink-address', dest='sink_address', type=str, help='demurrage level,ppm per minute') 
+argparser.add_argument('--redistribution-period', type=int, help='redistribution period, minutes (0 = deactivate)') # default 10080 = week
+argparser.add_argument('--demurrage-level', dest='demurrage_level', type=int, help='demurrage level, ppm per period') 
 args = argparser.parse_args()
 
-if args.vv:
-    logg.setLevel(logging.DEBUG)
-elif args.v:
-    logg.setLevel(logging.INFO)
+logg = process_log(args, logg)
 
-block_last = args.w
-block_all = args.ww
+config = Config()
+config = process_config(config, arg, args, flags)
+config = process_config_local(config, arg, args, flags)
+logg.debug('config loaded:\n{}'.format(config))
 
-passphrase_env = 'ETH_PASSPHRASE'
-if args.env_prefix != None:
-    passphrase_env = args.env_prefix + '_' + passphrase_env
-passphrase = os.environ.get(passphrase_env)
-if passphrase == None:
-    logg.warning('no passphrase given')
-    passphrase=''
+settings = ChainSettings()
+settings = process_settings(settings, config)
+logg.debug('settings loaded:\n{}'.format(settings))
 
-signer_address = None
-keystore = DictKeystore()
-if args.y != None:
-    logg.debug('loading keystore file {}'.format(args.y))
-    signer_address = keystore.import_keystore_file(args.y, password=passphrase)
-    logg.debug('now have key for signer address {}'.format(signer_address))
-signer = EIP155Signer(keystore)
 
-chain_spec = ChainSpec.from_chain_str(args.i)
-
-rpc = EthHTTPConnection(args.p)
-nonce_oracle = None
-if args.nonce != None:
-    nonce_oracle = OverrideNonceOracle(signer_address, args.nonce)
-else:
-    nonce_oracle = RPCNonceOracle(signer_address, rpc)
-
-gas_oracle = None
-if args.gas_price !=None:
-    gas_oracle = OverrideGasOracle(price=args.gas_price, conn=rpc, code_callback=DemurrageToken.gas)
-else:
-    gas_oracle = RPCGasOracle(rpc, code_callback=DemurrageToken.gas)
-
-dummy = args.d
-
-token_name = args.name
-if token_name == None:
-    token_name = args.symbol
+#extra_args = {
+#        'redistribution_period': 'TOKEN_REDISTRIBUTION_PERIOD',
+#        'demurrage_level': 'TOKEN_DEMURRAGE_LEVEL',
+#        'supply_limit': 'TOKEN_SUPPLY_LIMIT',
+#        'token_name': 'TOKEN_NAME',
+#        'token_symbol': 'TOKEN_SYMBOL',
+#        'token_decimals': 'TOKEN_DECIMALS',
+#        'sink_address': 'TOKEN_SINK_ADDRESS',
+#        'multi': None,
+#        }
+#config = chainlib.eth.cli.Config.from_args(args, arg_flags, extra_args=extra_args, default_fee_limit=DemurrageToken.gas(), base_config_dir=config_dir)
+#
+#if not bool(config.get('TOKEN_NAME')):
+#    logg.info('token name not set, using symbol {} as name'.format(config.get('TOKEN_SYMBOL')))
+#    config.add(config.get('TOKEN_SYMBOL'), 'TOKEN_NAME', True)
+#
+#if config.get('TOKEN_SUPPLY_LIMIT') == None:
+#    config.add(0, 'TOKEN_SUPPLY_LIMIT', True)
+#
+#if config.get('TOKEN_REDISTRIBUTION_PERIOD') == None:
+#    config.add(10800, 'TOKEN_REDISTRIBUTION_PERIOD', True)
+#logg.debug('config loaded:\n{}'.format(config))
+#
+#wallet = chainlib.eth.cli.Wallet()
+#wallet.from_config(config)
+#
+#rpc = chainlib.eth.cli.Rpc(wallet=wallet)
+#conn = rpc.connect_by_config(config)
+#
+#chain_spec = ChainSpec.from_chain_str(config.get('CHAIN_SPEC'))
 
 def main():
-    c = DemurrageToken(chain_spec, signer=signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
-    (tx_hash_hex, o) = c.constructor(
-            signer_address,
-            token_name,
-            args.symbol,
-            args.decimals,
-            args.demurrage_level,
-            args.redistribution_period,
-            args.sink_address,
+    conn = settings.get('CONN')
+    c = DemurrageToken(
+            settings.get('CHAIN_SPEC'),
+            signer=settings.get('SIGNER'),
+            gas_oracle=settings.get('FEE_ORACLE'),
+            nonce_oracle=settings.get('NONCE_ORACLE'),
             )
-    if dummy:
-        print(tx_hash_hex)
-        print(o)
-    else:
-        rpc.do(o)
-        if block_last:
-            r = rpc.wait(tx_hash_hex)
+    token_settings = DemurrageTokenSettings()
+    token_settings.name = config.get('TOKEN_NAME')
+    token_settings.symbol = config.get('TOKEN_SYMBOL')
+    token_settings.decimals = int(config.get('TOKEN_DECIMALS'))
+    token_settings.demurrage_level = int(config.get('TOKEN_DEMURRAGE_LEVEL'))
+    token_settings.period_minutes = int(config.get('TOKEN_REDISTRIBUTION_PERIOD'))
+    token_settings.sink_address = config.get('TOKEN_SINK_ADDRESS')
+
+    (tx_hash_hex, o) = c.constructor(
+            settings.get('SENDER_ADDRESS'),
+            token_settings,
+            )
+    if settings.get('RPC_SEND'):
+        conn.do(o)
+        if config.true('_WAIT'):
+            r = conn.wait(tx_hash_hex)
             if r['status'] == 0:
                 sys.stderr.write('EVM revert while deploying contract. Wish I had more to tell you')
                 sys.exit(1)
@@ -130,6 +167,9 @@ def main():
         else:
             print(tx_hash_hex)
 
+    else:
+        print(o)
+
 
 if __name__ == '__main__':
     main()

python/erc20_demurrage_token/seal.py

@@ -0,0 +1,66 @@
+# standard imports
+import enum
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.jsonrpc import JSONRPCRequest
+from chainlib.eth.tx import (
+        TxFactory,
+        TxFormat,
+        )
+from chainlib.eth.contract import (
+        ABIContractEncoder,
+        ABIContractType,
+        abi_decode_single,
+        )
+from hexathon import (
+        add_0x,
+        )
+
+class ContractState(enum.IntEnum):
+    MINTER_STATE = 1
+    SINK_STATE = 2
+    EXPIRY_STATE = 4
+    CAP_STATE = 8
+
+CONTRACT_SEAL_STATE_MAX = 0
+
+for v in dir(ContractState):
+    if len(v) > 6 and v[-6:] == '_STATE':
+       CONTRACT_SEAL_STATE_MAX += getattr(ContractState, v).value
+
+
+class SealedContract(TxFactory):
+
+    def seal(self, contract_address, sender_address, seal, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('seal')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(seal)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
+    def is_sealed(self, contract_address, v, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('isSealed')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(v)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    @classmethod
+    def parse_is_sealed(self, v):
+        return abi_decode_single(ABIContractType.BOOLEAN, v)

python/erc20_demurrage_token/sim/__init__.py

@@ -0,0 +1,2 @@
+from .sim import DemurrageTokenSimulation
+from .error import TxLimitException

python/erc20_demurrage_token/sim/error.py

@@ -0,0 +1,2 @@
+class TxLimitException(RuntimeError):
+    pass

python/erc20_demurrage_token/sim/sim.py

@@ -0,0 +1,302 @@
+# standard imports
+import logging
+
+# external imports
+from chainlib.chain import ChainSpec
+from chainlib.eth.unittest.ethtester import create_tester_signer
+from chainlib.eth.unittest.base import TestRPCConnection
+from chainlib.eth.tx import (
+        receipt,
+        Tx,
+        )
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.gas import (
+        OverrideGasOracle,
+        Gas,
+        )
+from chainlib.eth.address import to_checksum_address
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        block_by_hash,
+        )
+from funga.eth.keystore.dict import DictKeystore
+from funga.eth.signer import EIP155Signer
+from hexathon import (
+        strip_0x,
+        add_0x,
+        )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token.sim.error import TxLimitException
+
+logg = logging.getLogger(__name__)
+
+
+class DemurrageTokenSimulation:
+
+    def __init__(self, chain_str, settings, redistribute=True, cap=0, actors=1):
+        self.chain_spec = ChainSpec.from_chain_str(chain_str)
+        self.accounts = []
+        self.redistribute = redistribute
+        self.keystore = DictKeystore()
+        self.signer = EIP155Signer(self.keystore)
+        self.eth_helper = create_tester_signer(self.keystore)
+        self.eth_backend = self.eth_helper.backend
+        self.gas_oracle = OverrideGasOracle(limit=100000, price=1)
+        self.rpc = TestRPCConnection(None, self.eth_helper, self.signer)
+        for a in self.keystore.list():
+            self.accounts.append(add_0x(to_checksum_address(a)))
+        settings.sink_address = self.accounts[0]
+
+        self.actors = []
+        for i in range(actors):
+            idx = i % 10
+            address = self.keystore.new()
+            self.actors.append(address)
+            self.accounts.append(address)
+
+            nonce_oracle = RPCNonceOracle(self.accounts[idx], conn=self.rpc)
+            c = Gas(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+            (tx_hash, o) = c.create(self.accounts[idx], address, 100000 * 1000000)
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            if r['status'] != 1:
+                raise RuntimeError('failed gas transfer to account #{}: {} from {}'.format(i, address, self.accounts[idx]))
+            logg.info('added actor account #{}: {} block {}'.format(i, address, r['block_number']))
+
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.constructor(self.accounts[0], settings, redistribute=redistribute, cap=cap)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        if (r['status'] != 1):
+            raise RuntimeError('contract deployment failed')
+        self.address = r['contract_address']
+        logg.info('deployed contract to {} block {}'.format(self.address, r['block_number']))
+
+        o = block_latest()
+        r = self.rpc.do(o)
+        self.last_block = r
+        self.start_block = self.last_block
+
+        o = block_by_number(r)
+        r = self.rpc.do(o)
+        self.last_timestamp = r['timestamp']
+        self.start_timestamp = self.last_timestamp
+
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.rpc)
+        o = c.decimals(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.decimals = c.parse_decimals(r)
+
+        self.period_seconds = settings.period_minutes * 60
+
+        self.period = 1
+        self.period_txs = []
+        self.period_tx_limit = self.period_seconds - 1
+        self.sink_address = settings.sink_address
+
+        logg.info('intialized at block {} timestamp {} period {} demurrage level {} sink address {} (first address in keystore)'.format(
+                self.last_block,
+                self.last_timestamp,
+                settings.period_minutes,
+                settings.demurrage_level,
+                settings.sink_address,
+                )
+            )
+
+        self.eth_helper.disable_auto_mine_transactions()
+
+        self.caller_contract = DemurrageToken(self.chain_spec)
+        self.caller_address = self.accounts[0]
+
+
+    def __check_limit(self):
+        if self.period_tx_limit == len(self.period_txs):
+            raise TxLimitException('reached period tx limit {}'.format(self.period_tx_limit))
+
+
+    def __check_tx(self, tx_hash):
+        o = receipt(tx_hash)
+        rcpt = self.rpc.do(o)
+        if rcpt['status'] == 0:
+            raise RuntimeError('tx {} (block {} index {}) failed'.format(tx_hash, self.last_block, rcpt['transaction_index']))
+        logg.debug('tx {} block {} index {} verified'.format(tx_hash, self.last_block, rcpt['transaction_index']))
+
+
+    def get_now(self):
+        o = block_latest()
+        r = self.rpc.do(o)
+        o = block_by_number(r, include_tx=False)
+        r = self.rpc.do(o)
+        return r['timestamp']
+
+
+    def get_minutes(self):
+        t = self.get_now()
+        return int((t - self.start_timestamp) / 60)
+
+
+    def get_start(self):
+        return self.start_timestamp
+
+
+    def get_period(self):
+        o = self.caller_contract.actual_period(self.address, sender_address=self.caller_address)
+        r = self.rpc.do(o)
+        return self.caller_contract.parse_actual_period(r)
+
+
+    def get_demurrage(self):
+        o = self.caller_contract.demurrage_amount(self.address, sender_address=self.caller_address)
+        r = self.rpc.do(o)
+        logg.info('demrrage amount {}'.format(r))
+        return float(self.caller_contract.parse_demurrage_amount(r) / (10 ** 38))
+
+
+    def get_supply(self):
+        o = self.caller_contract.total_supply(self.address, sender_address=self.caller_address)
+        r = self.rpc.do(o)
+        supply = self.caller_contract.parse_total_supply(r)
+        return supply
+
+
+    def from_units(self, v):
+        return v * (10 ** self.decimals)
+
+
+    def mint(self, recipient, value):
+        self.__check_limit()
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], recipient, value)
+        self.rpc.do(o)
+        self.__next_block()
+        self.__check_tx(tx_hash)
+        self.period_txs.append(tx_hash)
+        logg.info('mint {} tokens to {} - {}'.format(value, recipient, tx_hash))
+        return tx_hash
+
+
+    def transfer(self, sender, recipient, value):
+        nonce_oracle = RPCNonceOracle(sender, conn=self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+        (tx_hash, o) = c.transfer(self.address, sender, recipient, value)
+        self.rpc.do(o)
+        self.__next_block()
+        self.__check_tx(tx_hash)
+        self.period_txs.append(tx_hash)
+        logg.info('transfer {} tokens from {} to {} - {}'.format(value, sender, recipient, tx_hash))
+        return tx_hash
+
+
+    def balance(self, holder, base=False):
+        o = None
+        if base:
+            o = self.caller_contract.base_balance_of(self.address, holder, sender_address=self.caller_address)
+        else:
+            o = self.caller_contract.balance_of(self.address, holder, sender_address=self.caller_address)
+        r = self.rpc.do(o)
+        return self.caller_contract.parse_balance(r)
+
+
+    def __next_block(self):
+        hsh = self.eth_helper.mine_block()
+        o = block_by_hash(hsh)
+        r = self.rpc.do(o)
+
+        for tx_hash in r['transactions']:
+            o = receipt(tx_hash)
+            rcpt = self.rpc.do(o)
+            if rcpt['status'] == 0:
+                raise RuntimeError('tx {} (block {} index {}) failed'.format(tx_hash, self.last_block, rcpt['transaction_index']))
+            logg.debug('tx {} (block {} index {}) verified'.format(tx_hash, self.last_block, rcpt['transaction_index']))
+
+        logg.debug('now at block {} timestamp {}'.format(r['number'], r['timestamp']))
+
+
+    def next(self):
+        target_timestamp = self.start_timestamp + (self.period * self.period_seconds)
+        logg.info('warping to {}, {} from start {}'.format(target_timestamp, target_timestamp - self.start_timestamp, self.start_timestamp))
+        self.last_timestamp = target_timestamp 
+
+        o = block_latest()
+        r = self.rpc.do(o)
+        self.last_block = r
+        o = block_by_number(r)
+        r = self.rpc.do(o)
+        cursor_timestamp = r['timestamp'] + 1
+
+        nonce_oracle = RPCNonceOracle(self.accounts[2], conn=self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+
+        i = 0
+        while cursor_timestamp < target_timestamp:
+            logg.info('mining block on {}'.format(cursor_timestamp))
+            (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[2])
+            self.rpc.do(o)
+            self.eth_helper.time_travel(cursor_timestamp + 60)
+            self.__next_block()
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            if r['status'] == 0:
+                raise RuntimeError('demurrage fast-forward failed on step {} timestamp {} block timestamp {} target {}'.format(i, cursor_timestamp, target_timestamp))
+            cursor_timestamp += 60*60 # 1 hour
+            o = block_by_number(r['block_number'])
+            b = self.rpc.do(o)
+            logg.info('block mined on timestamp {} (delta {}) block number {}'.format(b['timestamp'], b['timestamp'] - self.start_timestamp, b['number']))
+            i += 1
+
+        
+        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[2])
+        self.rpc.do(o)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[3], conn=self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+        (tx_hash, o) = c.change_period(self.address, self.accounts[3])
+        self.rpc.do(o)
+        self.eth_helper.time_travel(target_timestamp + 1)
+        self.__next_block()
+    
+        o = block_latest()
+        r = self.rpc.do(o)
+        o = block_by_number(self.last_block)
+        r = self.rpc.do(o)
+        self.last_block = r['number']
+        block_base = self.last_block
+        logg.info('block before demurrage execution {} {}'.format(r['timestamp'], r['number']))
+
+        if self.redistribute:
+            for actor in self.actors:
+                nonce_oracle = RPCNonceOracle(actor, conn=self.rpc)
+                c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+                (tx_hash, o) = c.apply_redistribution_on_account(self.address, actor, actor)
+                self.rpc.do(o)
+
+            nonce_oracle = RPCNonceOracle(self.sink_address, conn=self.rpc)
+            c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=self.gas_oracle)
+            (tx_hash, o) = c.apply_redistribution_on_account(self.address, self.sink_address, self.sink_address)
+            self.rpc.do(o)
+
+        self.__next_block()
+
+        o = block_latest()
+        self.last_block = self.rpc.do(o)
+
+        o = block_by_number(self.last_block)
+        r = self.rpc.do(o)
+        for tx_hash in r['transactions']:
+            o = receipt(tx_hash)
+            rcpt = self.rpc.do(o)
+            if rcpt['status'] == 0:
+                raise RuntimeError('demurrage step failed on block {}'.format(self.last_block))
+
+        self.last_timestamp = r['timestamp']
+        logg.debug('next concludes at block {} timestamp {}, {} after start'.format(self.last_block, self.last_timestamp, self.last_timestamp - self.start_timestamp))
+        self.period += 1
+        self.period_txs = []
+
+        return (self.last_block, self.last_timestamp)

python/erc20_demurrage_token/token.py

@@ -10,23 +10,49 @@ from chainlib.eth.tx import (
 from chainlib.hash import keccak256_string_to_hex
 from chainlib.eth.contract import (
         ABIContractEncoder,
+        ABIContractDecoder,
         ABIContractType,
         abi_decode_single,
         )
 from chainlib.eth.constant import ZERO_ADDRESS
-from chainlib.jsonrpc import jsonrpc_template
+from chainlib.jsonrpc import JSONRPCRequest
 from eth_erc20 import ERC20
 from hexathon import (
         add_0x,
         strip_0x,
         )
+from dexif import from_fixed
 
 # local imports
 from erc20_demurrage_token.data import data_dir
+from erc20_demurrage_token.seal import SealedContract
+from erc20_demurrage_token.expiry import ExpiryContract
 
 logg = logging.getLogger(__name__)
 
 
+class DemurrageRedistribution:
+    
+    def __init__(self, v):
+        d = ABIContractDecoder()
+        v = strip_0x(v)
+        d.typ(ABIContractType.UINT256)
+        d.typ(ABIContractType.UINT256)
+        d.typ(ABIContractType.BYTES32)
+        d.val(v[:64])
+        d.val(v[64:128])
+        d.val(v[128:192])
+        r = d.decode()
+
+        self.period = r[0]
+        self.value = r[1]
+        self.demurrage = from_fixed(r[2])
+
+
+    def __str__(self):
+        return 'period {} value {} demurrage {}'.format(self.period, self.value, self.demurrage)
+
+
 class DemurrageTokenSettings:
 
     def __init__(self):
@@ -38,21 +64,22 @@ class DemurrageTokenSettings:
         self.sink_address = None
 
 
-class DemurrageToken(ERC20):
+    def __str__(self):
+        return 'name {} demurrage level {} period minutes {} sink address {}'.format(
+                self.name,
+                self.demurrage_level,
+                self.period_minutes,
+                self.sink_address,
+                )
+
+
+class DemurrageToken(ERC20, SealedContract, ExpiryContract):
 
     __abi = {}
     __bytecode = {}
-    valid_modes = [
-                'MultiNocap',
-                'SingleNocap',
-                'MultiCap',
-                'SingleCap',
-                ]
 
-    def constructor(self, sender_address, settings, redistribute=True, cap=0, tx_format=TxFormat.JSONRPC):
-        if int(cap) < 0:
-            raise ValueError('cap must be 0 or positive integer')
-        code = DemurrageToken.bytecode(multi=redistribute, cap=cap>0)
+    def constructor(self, sender_address, settings, tx_format=TxFormat.JSONRPC):
+        code = DemurrageToken.bytecode()
         enc = ABIContractEncoder()
         enc.string(settings.name)
         enc.string(settings.symbol)
@@ -60,8 +87,6 @@ class DemurrageToken(ERC20):
         enc.uint256(settings.demurrage_level)
         enc.uint256(settings.period_minutes)
         enc.address(settings.sink_address)
-        if cap > 0:
-            enc.uint256(cap)
         code += enc.get()
         tx = self.template(sender_address, None, use_nonce=True)
         tx = self.set_code(tx, code)
@@ -70,26 +95,12 @@ class DemurrageToken(ERC20):
 
     @staticmethod
     def gas(code=None):
-        return 3500000
+        return 4000000
 
 
     @staticmethod
-    def __to_contract_name(multi, cap):
-        name = 'DemurrageToken'
-        if multi:
-            name += 'Multi'
-        else:
-            name += 'Single'
-        if cap:
-            name += 'Cap'
-        else:
-            name += 'Nocap'
-        return name
-
-
-    @staticmethod
-    def abi(multi=True, cap=False):
-        name = DemurrageToken.__to_contract_name(multi, cap)
+    def abi(multi=True):
+        name = 'DemurrageTokenSingleNocap'
         if DemurrageToken.__abi.get(name) == None:
             f = open(os.path.join(data_dir, name + '.json'), 'r')
             DemurrageToken.__abi[name] = json.load(f)
@@ -98,8 +109,8 @@ class DemurrageToken(ERC20):
 
 
     @staticmethod
-    def bytecode(multi=True, cap=False):
-        name = DemurrageToken.__to_contract_name(multi, cap)
+    def bytecode(multi=True):
+        name = 'DemurrageTokenSingleNocap'
         if DemurrageToken.__bytecode.get(name) == None:
             f = open(os.path.join(data_dir, name + '.bin'), 'r')
             DemurrageToken.__bytecode[name] = f.read()
@@ -107,6 +118,34 @@ class DemurrageToken(ERC20):
         return DemurrageToken.__bytecode[name]
 
 
+    def increase_allowance(self, contract_address, sender_address, address, value, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('increaseAllowance')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.typ(ABIContractType.UINT256)
+        enc.address(address)
+        enc.uint256(value)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
+    def decrease_allowance(self, contract_address, sender_address, address, value, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('decreaseAllowance')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.typ(ABIContractType.UINT256)
+        enc.address(address)
+        enc.uint256(value)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
     def add_minter(self, contract_address, sender_address, address, tx_format=TxFormat.JSONRPC):
         enc = ABIContractEncoder()
         enc.method('addMinter')
@@ -119,6 +158,17 @@ class DemurrageToken(ERC20):
         return tx
 
 
+    def set_max_supply(self, contract_address, sender_address, cap, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('setMaxSupply')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(cap)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
     def remove_minter(self, contract_address, sender_address, address, tx_format=TxFormat.JSONRPC):
         enc = ABIContractEncoder()
         enc.method('removeMinter')
@@ -145,8 +195,36 @@ class DemurrageToken(ERC20):
         return tx
 
 
-    def to_base_amount(self, contract_address, value, sender_address=ZERO_ADDRESS):
-        o = jsonrpc_template()
+    def burn(self, contract_address, sender_address, value, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('burn')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(value)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
+    def total_burned(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('totalBurned')
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def to_base_amount(self, contract_address, value, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('toBaseAmount')
@@ -157,11 +235,13 @@ class DemurrageToken(ERC20):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
+        o = j.finalize(o)
         return o
 
 
-    def remainder(self, contract_address, parts, whole, sender_address=ZERO_ADDRESS):
-        o = jsonrpc_template()
+    def remainder(self, contract_address, parts, whole, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('remainder')
@@ -174,11 +254,13 @@ class DemurrageToken(ERC20):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
+        o = j.finalize(o)
         return o
 
 
-    def redistributions(self, contract_address, idx, sender_address=ZERO_ADDRESS):
-        o = jsonrpc_template()
+    def redistributions(self, contract_address, idx, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('redistributions')
@@ -189,11 +271,13 @@ class DemurrageToken(ERC20):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
+        o = j.finalize(o)
         return o
 
 
-    def account_period(self, contract_address, address, sender_address=ZERO_ADDRESS):
-        o = jsonrpc_template()
+    def account_period(self, contract_address, address, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('accountPeriod')
@@ -204,26 +288,157 @@ class DemurrageToken(ERC20):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
+        o = j.finalize(o)
         return o
 
 
-    def to_redistribution_period(self, contract_address, redistribution, sender_address=ZERO_ADDRESS):
-        o = jsonrpc_template()
+    def to_redistribution(self, contract_address, participants, demurrage_modifier, value, period, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
-        enc.method('toRedistributionPeriod')
-        enc.typ(ABIContractType.BYTES32)
-        enc.bytes32(redistribution)
+        enc.method('toRedistribution')
+        enc.typ(ABIContractType.UINT256)
+        enc.typ_literal('int128')
+        enc.typ(ABIContractType.UINT256)
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(participants)
+        enc.uint256(demurrage_modifier)
+        enc.uint256(value)
+        enc.uint256(period)
         data = add_0x(enc.get())
         tx = self.template(sender_address, contract_address)
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
+        o = j.finalize(o)
         return o
 
 
-    def apply_demurrage(self, contract_address, sender_address):
-        return self.transact_noarg('applyDemurrage', contract_address, sender_address)
+
+    def to_redistribution_period(self, contract_address, redistribution, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('toRedistributionPeriod')
+        v = strip_0x(redistribution)
+        enc.typ_literal('(uint32,uint72,uint64)')
+        enc.bytes32(v[:64])
+        enc.bytes32(v[64:128])
+        enc.bytes32(v[128:192])
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+#    def to_redistribution_participants(self, contract_address, redistribution, sender_address=ZERO_ADDRESS, id_generator=None):
+#        j = JSONRPCRequest(id_generator)
+#        o = j.template()
+#        o['method'] = 'eth_call'
+#        enc = ABIContractEncoder()
+#        enc.method('toRedistributionParticipants')
+#        v = strip_0x(redistribution)
+#        enc.typ_literal('(uint32,uint72,uint104)')
+#        #enc.typ(ABIContractType.BYTES32)
+#        enc.bytes32(v[:64])
+#        enc.bytes32(v[64:128])
+#        enc.bytes32(v[128:192])
+#        data = add_0x(enc.get())
+#        tx = self.template(sender_address, contract_address)
+#        tx = self.set_code(tx, data)
+#        o['params'].append(self.normalize(tx))
+#        o['params'].append('latest')
+#        o = j.finalize(o)
+#        return o
+#
+
+    def to_redistribution_supply(self, contract_address, redistribution, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('toRedistributionSupply')
+        v = strip_0x(redistribution)
+        enc.typ_literal('(uint32,uint72,uint64)')
+        enc.bytes32(v[:64])
+        enc.bytes32(v[64:128])
+        enc.bytes32(v[128:192])
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def to_redistribution_demurrage_modifier(self, contract_address, redistribution, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('toRedistributionDemurrageModifier')
+        v = strip_0x(redistribution)
+        enc.typ_literal('(uint32,uint72,uint64)')
+        enc.bytes32(v[:64])
+        enc.bytes32(v[64:128])
+        enc.bytes32(v[128:192])
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def base_balance_of(self, contract_address, address, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('baseBalanceOf')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.address(address)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def set_sink_address(self, contract_address, sender_address, address, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('setSinkAddress')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.address(address)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
+
+
+    def apply_demurrage(self, contract_address, sender_address, limit=0, tx_format=TxFormat.JSONRPC):
+        if limit == 0:
+            return self.transact_noarg('applyDemurrage', contract_address, sender_address)
+
+        enc = ABIContractEncoder()
+        enc.method('applyDemurrageLimited')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(limit)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
 
 
     def change_period(self, contract_address, sender_address):
@@ -240,7 +455,17 @@ class DemurrageToken(ERC20):
         tx = self.set_code(tx, data)
         tx = self.finalize(tx, tx_format)
         return tx
-       
+
+
+
+
+    def tax_level(self, contract_address, sender_address=ZERO_ADDRESS):
+        return self.call_noarg('taxLevel', contract_address, sender_address=sender_address)
+
+
+    def resolution_factor(self, contract_address, sender_address=ZERO_ADDRESS):
+        return self.call_noarg('resolutionFactor', contract_address, sender_address=sender_address)
+
 
     def actual_period(self, contract_address, sender_address=ZERO_ADDRESS):
         return self.call_noarg('actualPeriod', contract_address, sender_address=sender_address)
@@ -258,8 +483,90 @@ class DemurrageToken(ERC20):
         return self.call_noarg('demurrageAmount', contract_address, sender_address=sender_address)
 
 
-    def supply_cap(self, contract_address, sender_address=ZERO_ADDRESS):
-        return self.call_noarg('supplyCap', contract_address, sender_address=sender_address)
+    def demurrage_timestamp(self, contract_address, sender_address=ZERO_ADDRESS):
+        return self.call_noarg('demurrageTimestamp', contract_address, sender_address=sender_address)
+
+
+    def max_supply(self, contract_address, sender_address=ZERO_ADDRESS):
+        return self.call_noarg('maxSupply', contract_address, sender_address=sender_address)
+
+
+#    def grow_by(self, contract_address, value, period, sender_address=ZERO_ADDRESS, id_generator=None):
+#        j = JSONRPCRequest(id_generator)
+#        o = j.template()
+#        o['method'] = 'eth_call'
+#        enc = ABIContractEncoder()
+#        enc.method('growBy')
+#        enc.typ(ABIContractType.UINT256)
+#        enc.typ(ABIContractType.UINT256)
+#        enc.uint256(value)
+#        enc.uint256(period)
+#        data = add_0x(enc.get())
+#        tx = self.template(sender_address, contract_address)
+#        tx = self.set_code(tx, data)
+#        o['params'].append(self.normalize(tx))
+#        o['params'].append('latest')
+#        o = j.finalize(o)
+#        return o
+#
+
+    def decay_by(self, contract_address, value, period, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('decayBy')
+        enc.typ(ABIContractType.UINT256)
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(value)
+        enc.uint256(period)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def get_distribution(self, contract_address, supply, demurrage_amount, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('getDistribution')
+        enc.typ(ABIContractType.UINT256)
+        enc.typ_literal('int128')
+        enc.uint256(supply)
+        enc.uint256(demurrage_amount)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
+    def get_distribution_from_redistribution(self, contract_address, redistribution, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('getDistributionFromRedistribution')
+        v = strip_0x(redistribution)
+        enc.typ_literal('(uint32,uint72,uint64)')
+        enc.bytes32(v[:64])
+        enc.bytes32(v[64:128])
+        enc.bytes32(v[128:192])
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
 
 
     @classmethod
@@ -279,7 +586,8 @@ class DemurrageToken(ERC20):
 
     @classmethod
     def parse_demurrage_amount(self, v):
-        return abi_decode_single(ABIContractType.UINT256, v)
+        #        return abi_decode_single(ABIContractType.UINT256, v)
+        return from_fixed(v)
 
 
     @classmethod
@@ -294,8 +602,8 @@ class DemurrageToken(ERC20):
     
     @classmethod
     def parse_redistributions(self, v):
-        return abi_decode_single(ABIContractType.BYTES32, v)
-
+        return strip_0x(v)
+        
 
     @classmethod
     def parse_account_period(self, v):
@@ -307,6 +615,42 @@ class DemurrageToken(ERC20):
         return abi_decode_single(ABIContractType.UINT256, v)
 
 
+    @classmethod
+    def parse_to_redistribution_item(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
     @classmethod
     def parse_supply_cap(self, v):
         return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_grow_by(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_decay_by(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_get_distribution(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_tax_level(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_resolution_factor(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_total_burned(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)
+

python/erc20_demurrage_token/unittest/__init__.py

@@ -0,0 +1 @@
+from .base import *

python/erc20_demurrage_token/unittest/base.py

@@ -0,0 +1,150 @@
+# standard imports
+import logging
+import os
+import math
+
+# external imports
+from chainlib.eth.unittest.ethtester import EthTesterCase
+from chainlib.eth.tx import (
+        receipt,
+        )
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        )
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.constant import ZERO_ADDRESS
+
+# local imports
+from erc20_demurrage_token import (
+        DemurrageTokenSettings,
+        DemurrageToken,
+        )
+from dexif import *
+
+logg = logging.getLogger()
+
+#BLOCKTIME = 5 # seconds
+TAX_LEVEL = int(10000 * 2) # 2%
+# calc "1-(0.98)^(1/518400)" <- 518400 = 30 days of blocks
+# 0.00000003897127107225
+PERIOD = 43200
+
+
+class TestTokenDeploy:
+
+    """tax level is ppm, 1000000 = 100%"""
+    def __init__(self, rpc, token_symbol='FOO', token_name='Foo Token', sink_address=ZERO_ADDRESS, tax_level=TAX_LEVEL, period=PERIOD):
+        self.tax_level = tax_level
+        self.period_seconds = period * 60
+
+        self.settings = DemurrageTokenSettings()
+        self.settings.name = token_name
+        self.settings.symbol = token_symbol
+        self.settings.decimals = 6
+        tax_level_input = to_fixed((1 - (tax_level / 1000000)) ** (1 / period))
+        self.settings.demurrage_level = tax_level_input
+        self.settings.period_minutes = period
+        self.settings.sink_address = sink_address
+        self.sink_address = self.settings.sink_address
+        logg.debug('using demurrage token settings: {}'.format(self.settings))
+
+        o = block_latest()
+        self.start_block = rpc.do(o)
+        
+        o = block_by_number(self.start_block, include_tx=False)
+        r = rpc.do(o)
+
+        try:
+            self.start_time = int(r['timestamp'], 16)
+        except TypeError:
+            self.start_time = int(r['timestamp'])
+
+
+    def deploy(self, rpc, deployer_address, interface, supply_cap=0):
+        tx_hash = None
+        o = None
+        (tx_hash, o) = interface.constructor(deployer_address, self.settings)
+
+        r = rpc.do(o)
+        o = receipt(tx_hash)
+        r = rpc.do(o)
+        assert r['status'] == 1
+        self.start_block = r['block_number']
+        self.address = r['contract_address']
+
+        o = block_by_number(r['block_number'])
+        r = rpc.do(o)
+        self.start_time = r['timestamp']
+
+        return self.address
+
+
+class TestDemurrage(EthTesterCase):
+
+    def setUp(self):
+        super(TestDemurrage, self).setUp()
+        period = PERIOD
+        try:
+            period = getattr(self, 'period')
+        except AttributeError as e:
+            pass
+        self.deployer = TestTokenDeploy(self.rpc, period=period, sink_address=self.accounts[9])
+        self.default_supply = 0
+        self.default_supply_cap = 0
+        self.start_block = None
+        self.address = None
+        self.start_time = None
+
+
+    def deploy(self, interface):
+        self.address = self.deployer.deploy(self.rpc, self.accounts[0], interface, supply_cap=self.default_supply_cap)
+        self.start_block = self.deployer.start_block
+        self.start_time = self.deployer.start_time
+        self.tax_level = self.deployer.tax_level
+        self.period_seconds = self.deployer.period_seconds
+        self.sink_address = self.deployer.sink_address
+
+        logg.debug('contract address {} start block {} start time {}'.format(self.address, self.start_block, self.start_time))
+
+
+    def assert_within(self, v, target, tolerance_ppm):
+        lower_target = target - (target * (tolerance_ppm / 1000000))
+        higher_target = target + (target * (tolerance_ppm / 1000000))
+        #self.assertGreaterEqual(v, lower_target)
+        #self.assertLessEqual(v, higher_target)
+        if v >= lower_target and v <= higher_target:
+            logg.debug('asserted within {} <= {} <= {}'.format(lower_target, v, higher_target))
+            return
+        raise AssertionError('{} not within lower {} and higher {}'.format(v, lower_target, higher_target))
+
+
+    def assert_within_lower(self, v, target, tolerance_ppm):
+        lower_target = target - (target * (tolerance_ppm / 1000000))
+        self.assertGreaterEqual(v, lower_target)
+        self.assertLessEqual(v, target)
+        logg.debug('asserted within lower {} <= {} <= {}'.format(lower_target, v, target))
+
+
+    def assert_equal_decimals(self, v, target, precision):
+        target = int(target * (10 ** precision))
+        target = target / (10 ** precision)
+        self.assertEqual(v, target)
+
+
+    def tearDown(self):
+        pass
+
+
+class TestDemurrageDefault(TestDemurrage):
+
+    def setUp(self):
+        super(TestDemurrageDefault, self).setUp()
+   
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        self.deploy(c)
+
+        self.default_supply = 10**12
+        self.default_supply_cap = self.default_supply

python/erc20_demurrage_token/unittest/newbase.py

@@ -0,0 +1,146 @@
+# standard imports
+import logging
+import os
+import math
+
+# external imports
+from chainlib.eth.unittest.ethtester import EthTesterCase
+from chainlib.eth.tx import (
+        receipt,
+        )
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        )
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.constant import ZERO_ADDRESS
+
+# local imports
+from erc20_demurrage_token import (
+        DemurrageTokenSettings,
+        DemurrageToken,
+        )
+from dexif import *
+
+logg = logging.getLogger()
+
+TAX_LEVEL = int(10000 * 2) # 2%
+PERIOD = 43200 # 30 days in minutes
+
+class TestTokenDeploy:
+
+    """tax level is ppm, 1000000 = 100%"""
+    def __init__(self, rpc, token_symbol='FOO', token_name='Foo Token', sink_address=ZERO_ADDRESS, supply=10**12, tax_level=TAX_LEVEL, period=PERIOD):
+        self.tax_level = tax_level
+        self.period_seconds = period * 60
+
+        self.settings = DemurrageTokenSettings()
+        self.settings.name = token_name
+        self.settings.symbol = token_symbol
+        self.settings.decimals = 6
+        tax_level_input = to_fixed((1 - (tax_level / 1000000)) ** (1 / period))
+        self.settings.demurrage_level = tax_level_input
+        self.settings.period_minutes = period
+        self.settings.sink_address = sink_address
+        self.sink_address = self.settings.sink_address
+        logg.debug('using demurrage token settings: {}'.format(self.settings))
+
+        o = block_latest()
+        self.start_block = rpc.do(o)
+        
+        o = block_by_number(self.start_block, include_tx=False)
+        r = rpc.do(o)
+
+        try:
+            self.start_time = int(r['timestamp'], 16)
+        except TypeError:
+            self.start_time = int(r['timestamp'])
+
+        self.default_supply = supply
+        self.default_supply_cap = 0
+
+
+    def deploy(self, rpc, deployer_address, interface, supply_cap=0):
+        tx_hash = None
+        o = None
+        (tx_hash, o) = interface.constructor(deployer_address, self.settings, redistribute=False, cap=0)
+
+        r = rpc.do(o)
+        o = receipt(tx_hash)
+        r = rpc.do(o)
+        assert r['status'] == 1
+        self.start_block = r['block_number']
+        self.address = r['contract_address']
+
+        o = block_by_number(r['block_number'])
+        r = rpc.do(o)
+        self.start_time = r['timestamp']
+
+        return self.address
+
+
+class TestDemurrage(EthTesterCase):
+
+    def setUp(self):
+        super(TestDemurrage, self).setUp()
+        period = PERIOD
+        try:
+            period = getattr(self, 'period')
+        except AttributeError as e:
+            pass
+        self.deployer = TestTokenDeploy(self.rpc, period=period)
+        self.default_supply = self.deployer.default_supply
+        self.default_supply_cap = self.deployer.default_supply_cap
+        self.start_block = None
+        self.address = None
+        self.start_time = None
+
+
+    def deploy(self, interface):
+        self.address = self.deployer.deploy(self.rpc, self.accounts[0], interface, supply_cap=self.default_supply_cap)
+        self.start_block = self.deployer.start_block
+        self.start_time = self.deployer.start_time
+        self.tax_level = self.deployer.tax_level
+        self.period_seconds = self.deployer.period_seconds
+        self.sink_address = self.deployer.sink_address
+
+        logg.debug('contract address {} start block {} start time {}'.format(self.address, self.start_block, self.start_time))
+
+
+    def assert_within(self, v, target, tolerance_ppm):
+        lower_target = target - (target * (tolerance_ppm / 1000000))
+        higher_target = target + (target * (tolerance_ppm / 1000000))
+        #self.assertGreaterEqual(v, lower_target)
+        #self.assertLessEqual(v, higher_target)
+        if v >= lower_target and v <= higher_target:
+            logg.debug('asserted within {} <= {} <= {}'.format(lower_target, v, higher_target))
+            return
+        raise AssertionError('{} not within lower {} and higher {}'.format(v, lower_target, higher_target))
+
+
+    def assert_within_lower(self, v, target, tolerance_ppm):
+        lower_target = target - (target * (tolerance_ppm / 1000000))
+        self.assertGreaterEqual(v, lower_target)
+        self.assertLessEqual(v, target)
+        logg.debug('asserted within lower {} <= {} <= {}'.format(lower_target, v, target))
+
+
+    def assert_equal_decimals(self, v, target, precision):
+        target = int(target * (10 ** precision))
+        target = target / (10 ** precision)
+        self.assertEqual(v, target)
+
+
+    def tearDown(self):
+        pass
+
+
+class TestDemurrageDefault(TestDemurrage):
+
+    def setUp(self):
+        super(TestDemurrageDefault, self).setUp()
+   
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        self.deploy(c)

python/examples/sim.py

@@ -0,0 +1,76 @@
+# standard imports
+import logging
+
+# local imports
+from erc20_demurrage_token import DemurrageTokenSettings
+from erc20_demurrage_token.sim import DemurrageTokenSimulation
+
+logging.basicConfig(level=logging.WARNING)
+logg = logging.getLogger()
+
+decay_per_minute = 0.000050105908373373 # equals approx 2% per month
+
+# parameters for simulation object
+settings = DemurrageTokenSettings()
+settings.name = 'Simulated Demurrage Token'
+settings.symbol = 'SIM'
+settings.decimals = 6
+settings.demurrage_level = int(decay_per_minute*(10**40))
+settings.period_minutes = 10800 # 1 week in minutes
+chain = 'evm:foochain:42'
+cap = (10 ** 6) * (10 ** 12)
+
+# instantiate simulation
+sim = DemurrageTokenSimulation(chain, settings, redistribute=True, cap=cap, actors=10)
+
+# name the usual suspects
+alice = sim.actors[0]
+bob = sim.actors[1]
+carol = sim.actors[2]
+
+# mint and transfer (every single action advances one block, and one second in time)
+sim.mint(alice, sim.from_units(100)) # 10000000 tokens
+sim.mint(bob, sim.from_units(100))
+sim.transfer(alice, carol, sim.from_units(50))
+
+# check that balances have been updated
+assert sim.balance(alice) == sim.from_units(50)
+assert sim.balance(bob) == sim.from_units(100)
+assert sim.balance(carol) == sim.from_units(50)
+
+# advance to next redistribution period
+sim.next()
+
+# inspect balances
+print('alice balance: demurraged {:>9d} base {:>9d}'.format(sim.balance(alice), sim.balance(alice, base=True)))
+print('bob balance:   demurraged {:>9d} base {:>9d}'.format(sim.balance(bob), sim.balance(bob, base=True)))
+print('carol balance: demurraged {:>9d} base {:>9d}'.format(sim.balance(carol), sim.balance(carol, base=True)))
+print('sink balance:  demurraged {:>9d} base {:>9d}'.format(sim.balance(sim.sink_address), sim.balance(sim.sink_address, base=True)))
+
+# get times
+minutes = sim.get_minutes()
+start = sim.get_now()
+timestamp = sim.get_start()
+period = sim.get_period()
+print('start {} now {} period {} minutes passed {}'.format(start, timestamp, period, minutes))
+
+
+contract_demurrage = 1 - sim.get_demurrage_modifier()    # demurrage in percent (float)
+frontend_demurrage = ((1 - decay_per_minute) ** minutes / 100)   # corresponding demurrage modifier (float)
+demurrage_delta = contract_demurrage - frontend_demurrage      # difference between demurrage in contract and demurrage calculated in frontend
+
+alice_checksum = 50000000 - (50000000 * frontend_demurrage) + (200000000 * frontend_demurrage) # alice's balance calculated with frontend demurrage
+print("""alice frontend balance {}
+alice contract balance {}
+frontend demurrage {}
+contract demurrage {}
+demurrage delta {}""".format(
+    alice_checksum,
+    sim.balance(alice),
+    frontend_demurrage,
+    contract_demurrage,
+    demurrage_delta),
+)
+
+balance_sum = sim.balance(alice) + sim.balance(bob) + sim.balance(carol)
+print('sum of contract demurraged balances {}'.format(balance_sum))

python/examples/sim_noredistribute.py

@@ -0,0 +1,80 @@
+# standard imports
+import logging
+
+# local imports
+from erc20_demurrage_token import DemurrageTokenSettings
+from erc20_demurrage_token.sim import DemurrageTokenSimulation
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+decay_per_minute = 0.00000050105908373373 # equals approx 2% per month
+
+# parameters for simulation object
+settings = DemurrageTokenSettings()
+settings.name = 'Simulated Demurrage Token'
+settings.symbol = 'SIM'
+settings.decimals = 6
+settings.demurrage_level = int(decay_per_minute*(10**38))
+#settings.period_minutes = 1 # 1 week in minutes
+settings.period_minutes = 60*24*7
+chain = 'evm:foochain:42'
+cap = (10 ** 6) * (10 ** 12)
+#cap = 0
+
+# instantiate simulation
+sim = DemurrageTokenSimulation(chain, settings, redistribute=False, cap=cap, actors=10)
+
+# name the usual suspects
+alice = sim.actors[0]
+bob = sim.actors[1]
+carol = sim.actors[2]
+
+# mint and transfer (every single action advances one block, and one second in time)
+sim.mint(alice, sim.from_units(100)) # 10000000 tokens
+sim.mint(bob, sim.from_units(100))
+sim.transfer(alice, carol, sim.from_units(50))
+
+# check that balances have been updated
+#assert sim.balance(alice) == sim.from_units(50)
+#assert sim.balance(bob) == sim.from_units(100)
+#assert sim.balance(carol) == sim.from_units(50)
+
+# advance to next redistribution period
+sim.next()
+
+# inspect balances
+print('alice balance: demurraged {:>9d} base {:>9d}'.format(sim.balance(alice), sim.balance(alice, base=True)))
+print('bob balance:   demurraged {:>9d} base {:>9d}'.format(sim.balance(bob), sim.balance(bob, base=True)))
+print('carol balance: demurraged {:>9d} base {:>9d}'.format(sim.balance(carol), sim.balance(carol, base=True)))
+print('sink balance:  demurraged {:>9d} base {:>9d}'.format(sim.balance(sim.sink_address), sim.balance(sim.sink_address, base=True)))
+
+# get times
+minutes = sim.get_minutes()
+timestamp = sim.get_now()
+start = sim.get_start()
+period = sim.get_period()
+print('start {} now {} period {} minutes passed {}'.format(start, timestamp, period, minutes))
+
+
+contract_demurrage = 1 - sim.get_demurrage()    # demurrage in percent (float)
+frontend_demurrage = 1.0 - ((1 - decay_per_minute) ** minutes)   # corresponding demurrage modifier (float)
+demurrage_delta = contract_demurrage - frontend_demurrage      # difference between demurrage in contract and demurrage calculated in frontend
+
+alice_checksum = 50000000 - (50000000 * frontend_demurrage) + (200000000 * frontend_demurrage) # alice's balance calculated with frontend demurrage
+#print("""alice frontend balance {}
+print("""alice contract balance {}
+frontend demurrage {:.38f}
+contract demurrage {:.38f}
+demurrage delta {:.38f}""".format(
+    alice_checksum,
+    sim.balance(alice),
+    frontend_demurrage,
+    contract_demurrage,
+    demurrage_delta),
+)
+
+balance_sum = sim.balance(alice) + sim.balance(bob) + sim.balance(carol) + sim.balance(sim.sink_address)
+supply = sim.get_supply()
+print('sum of contract demurraged balances {}'.format(balance_sum))
+print('total token supply {}'.format(supply))

python/requirements.txt

@@ -1,3 +1,4 @@
-chainlib~=0.0.3rc3
-eth-erc20~=0.0.9a4
-crypto-dev-signer~=0.4.14b3
+chainlib-eth~=0.4.11
+eth-erc20~=0.5.0
+funga-eth~=0.6.0
+dexif~=0.0.1

python/run_tests.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+set -a
+set -e
+set -x
+default_pythonpath=$PYTHONPATH:.
+export PYTHONPATH=${default_pythonpath:-.}
+>&2 echo using pythonpath $PYTHONPATH
+for f in `ls tests/test_*.py`; do
+	python $f
+done
+set +x
+set +e
+set +a

python/setup.cfg

@@ -1,10 +1,10 @@
 [metadata]
 name = erc20-demurrage-token
-version = 0.0.1b1
+version = 0.3.0
 description = ERC20 token with redistributed continual demurrage
 author = Louis Holbrook
 author_email = dev@holbrook.no
-url = https://gitlab.com/grassrootseconomics/sarafu-token
+url = https://gitlab.com/ccicnet/erc20-demurrage-token
 keywords =
 	ethereum
 	blockchain
@@ -25,10 +25,13 @@ licence_files =
 
 [options]
 include_package_data = True
-python_requires = >= 3.6
+python_requires = >= 3.7
 packages =
 	erc20_demurrage_token
 	erc20_demurrage_token.runnable
+	erc20_demurrage_token.data
+	erc20_demurrage_token.sim
+	erc20_demurrage_token.unittest
 
 [options.package_data]
 * =
@@ -38,3 +41,4 @@ packages =
 [options.entry_points]
 console_scripts =
 	erc20-demurrage-token-deploy = erc20_demurrage_token.runnable.deploy:main
+	erc20-demurrage-token-apply = erc20_demurrage_token.runnable.apply:main

python/test.sh

@@ -1,29 +0,0 @@
-#!/bin/bash
-
-set -e
-
-export PYTHONPATH=.
-
-modes=(MultiNocap MultiCap SingleCap SingleNocap)
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_pure.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_period.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_basic.py
-done
-
-modes=(MultiCap SingleCap)
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_cap.py
-done
-
-modes=(SingleCap SingleNocap)
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_single.py
-done
-
-modes=(MultiCap MultiNocap)
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution.py
-done
-
-set +e

python/test_requirements.txt

@@ -1,3 +1,2 @@
-#web3==5.12.2
 eth_tester==0.5.0b3
 py-evm==0.3.0a20

python/tests/base.py

@@ -1,165 +0,0 @@
-# standard imports
-import logging
-import os
-
-# external imports
-from chainlib.eth.unittest.ethtester import EthTesterCase
-from chainlib.eth.tx import (
-        receipt,
-        )
-from chainlib.eth.block import (
-        block_latest,
-        block_by_number,
-        )
-from chainlib.eth.nonce import RPCNonceOracle
-
-# local imports
-from erc20_demurrage_token import (
-        DemurrageTokenSettings,
-        DemurrageToken,
-        )
-
-
-logg = logging.getLogger()
-
-
-#BLOCKTIME = 5 # seconds
-TAX_LEVEL = int(10000 * 2) # 2%
-# calc "1-(0.98)^(1/518400)" <- 518400 = 30 days of blocks
-# 0.00000003897127107225
-#PERIOD = int(60/BLOCKTIME) * 60 * 24 * 30 # month
-PERIOD = 1
-
-
-
-class TestDemurrage(EthTesterCase):
-
-    def setUp(self):
-        super(TestDemurrage, self).setUp()
-
-        self.tax_level = TAX_LEVEL
-        self.period_seconds = PERIOD * 60
-
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        self.settings = DemurrageTokenSettings()
-        self.settings.name = 'Foo Token'
-        self.settings.symbol = 'FOO'
-        self.settings.decimals = 6
-        self.settings.demurrage_level = TAX_LEVEL * (10 ** 32)
-        self.settings.period_minutes = PERIOD
-        self.settings.sink_address = self.accounts[9]
-        self.sink_address = self.settings.sink_address
-
-        o = block_latest()
-        self.start_block = self.rpc.do(o)
-        
-        o = block_by_number(self.start_block, include_tx=False)
-        r = self.rpc.do(o)
-
-        try:
-            self.start_time = int(r['timestamp'], 16)
-        except TypeError:
-            self.start_time = int(r['timestamp'])
-
-        self.default_supply = 1000000000000
-        self.default_supply_cap = int(self.default_supply * 10)
-
-
-    def deploy(self, interface, mode):
-        tx_hash = None
-        o = None
-        if mode == 'MultiNocap':
-            (tx_hash, o) = interface.constructor(self.accounts[0], self.settings, redistribute=True, cap=0)
-        elif mode == 'SingleNocap':
-            (tx_hash, o) = interface.constructor(self.accounts[0], self.settings, redistribute=False, cap=0)
-        elif mode == 'MultiCap':
-            (tx_hash, o) = interface.constructor(self.accounts[0], self.settings, redistribute=True, cap=self.default_supply_cap)
-        elif mode == 'SingleCap':
-            (tx_hash, o) = interface.constructor(self.accounts[0], self.settings, redistribute=False, cap=self.default_supply_cap)
-        else:
-            raise ValueError('Invalid mode "{}", valid are {}'.format(self.mode, DemurrageToken.valid_modes))
-
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-        self.start_block = r['block_number']
-        self.address = r['contract_address']
-
-        o = block_by_number(r['block_number'])
-        r = self.rpc.do(o)
-        self.start_time = r['timestamp']
-
-        logg.debug('contract address {} start block {} start time {}'.format(self.address, self.start_block, self.start_time))
-
-
-    def tearDown(self):
-        pass
-
-
-class TestDemurrageDefault(TestDemurrage):
-
-    def setUp(self):
-        super(TestDemurrageDefault, self).setUp()
-   
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-
-        self.mode = os.environ.get('ERC20_DEMURRAGE_TOKEN_TEST_MODE')
-        if self.mode == None:
-            self.mode = 'MultiNocap'
-        logg.debug('executing test setup default mode {}'.format(self.mode))
-
-        self.deploy(c, self.mode)
-
-        logg.info('deployed with mode {}'.format(self.mode))
-
-
-class TestDemurrageSingle(TestDemurrage):
-
-    def setUp(self):
-        super(TestDemurrageSingle, self).setUp()
-   
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-
-        self.mode = os.environ.get('ERC20_DEMURRAGE_TOKEN_TEST_MODE')
-        single_valid_modes = [
-                    'SingleNocap',
-                    'SingleCap',
-                    ]
-        if self.mode != None:
-            if self.mode not in single_valid_modes:
-                raise ValueError('Invalid mode "{}" for "single" contract tests, valid are {}'.format(self.mode, single_valid_modes))
-        else:
-            self.mode = 'SingleNocap'
-        logg.debug('executing test setup demurragesingle mode {}'.format(self.mode))
-
-        self.deploy(c, self.mode)
-
-        logg.info('deployed with mode {}'.format(self.mode))
-
-
-class TestDemurrageCap(TestDemurrage):
-
-    def setUp(self):
-        super(TestDemurrageCap, self).setUp()
-   
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-
-        self.mode = os.environ.get('ERC20_DEMURRAGE_TOKEN_TEST_MODE')
-        cap_valid_modes = [
-                    'MultiCap',
-                    'SingleCap',
-                    ]
-        if self.mode != None:
-            if self.mode not in cap_valid_modes:
-                raise ValueError('Invalid mode "{}" for "cap" contract tests, valid are {}'.format(self.mode, cap_valid_modes))
-        else:
-            self.mode = 'MultiCap'
-        logg.debug('executing test setup demurragecap mode {}'.format(self.mode))
-
-        self.deploy(c, self.mode)
-
-        logg.info('deployed with mode {}'.format(self.mode))

python/tests/bench_gas.py

@@ -0,0 +1,167 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+import datetime
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+
+class BenchBasic(TestDemurrageDefault):
+
+    def setUp(self):
+        super(BenchBasic, self).setUp()
+        self.bench = {
+    'mint': None,
+    'transfer_light': None,
+    'transfer_heavy': None,
+    'approve': None,
+    'transfer_from': None,
+    'period_light': None,
+    'period_heavy': None,
+    'period_catchup': None,
+    'demurrage': None,
+        }
+
+
+    def test_bench_min(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.bench['mint'] = r['gas_used']
+        
+        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.accounts[1], self.accounts[2], 512)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.bench['transfer_light'] = r['gas_used']
+
+        (tx_hash, o) = c.approve(self.address, self.accounts[1], self.accounts[0], 512)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.bench['approve'] = r['gas_used']
+
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer_from(self.address, self.accounts[0], self.accounts[1], self.accounts[3], 256)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.bench['transfer_from'] = r['gas_used']
+
+        z = 0
+        for i in range(100):
+            self.backend.time_travel(self.start_time + int(self.period_seconds / 2) + (10 * (i * (i + 1))))
+            (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+            z += r['gas_used']
+            logg.info('demurrage round {} gas {}'.format(i, r['gas_used']))
+        z /= 100
+        self.bench['demurrage'] = int(z)
+
+        z = 0
+        for i in range(100):
+            self.backend.time_travel(self.start_time + (self.period_seconds * (i + 1)))
+            (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+            z += r['gas_used']
+            logg.info('period with demurrage round {} gas {}'.format(i, r['gas_used']))
+
+        z /= 100
+        self.bench['period_heavy'] = int(z)
+
+        z = 0
+        for i in range(100):
+            self.backend.time_travel(self.start_time + (self.period_seconds * ((i + 101))))
+            (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+            z += r['gas_used']
+            logg.info('period without demurrage round {} gas {}'.format(i, r['gas_used']))
+
+        z /= 100
+        self.bench['period_light'] = int(z)
+
+        z = 0
+        self.backend.time_travel(self.start_time + (self.period_seconds * 401))
+        for i in range(100):
+            (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+            z += r['gas_used']
+            logg.info('period catchup round {} gas {}'.format(i, r['gas_used']))
+
+        z /= 100
+        self.bench['period_catchup'] = int(z)
+
+        self.backend.time_travel(self.start_time + (self.period_seconds * 501))
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[2], 1024)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.backend.time_travel(self.start_time + (self.period_seconds * 502))
+
+        nonce_oracle = RPCNonceOracle(self.accounts[2], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.accounts[2], self.accounts[4], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.bench['transfer_heavy'] = r['gas_used']
+
+        print(json.dumps(self.bench))
+
+
+
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/sim/tests_sim.py

@@ -0,0 +1,73 @@
+# standard imports
+import unittest
+import logging
+
+# local imports
+from erc20_demurrage_token import DemurrageTokenSettings
+from erc20_demurrage_token.sim import DemurrageTokenSimulation
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+
+class TestSim(unittest.TestCase):
+
+    def setUp(self):
+        self.cap = 0
+        settings = DemurrageTokenSettings()
+        settings.name = 'Simulated Demurrage Token'
+        settings.symbol = 'SIM'
+        settings.decimals = 6
+        settings.demurrage_level = 5010590837337300000000000000000000 # equals approx 2% per month
+        settings.period_minutes = 10800 # 1 week in minutes
+        self.sim = DemurrageTokenSimulation('evm:foochain:42', settings, redistribute=True, cap=self.cap, actors=10)
+
+
+    def test_mint(self):
+        self.sim.mint(self.sim.actors[0], 1024)
+        self.sim.next()
+        balance = self.sim.balance(self.sim.actors[0])
+        self.assertEqual(balance, 1023)
+
+
+    def test_transfer(self):
+        self.sim.mint(self.sim.actors[0], 1024)
+        self.sim.transfer(self.sim.actors[0], self.sim.actors[1], 500)
+        self.sim.next()
+        balance = self.sim.balance(self.sim.actors[0])
+        self.assertEqual(balance, 523)
+
+        balance = self.sim.balance(self.sim.actors[1])
+        self.assertEqual(balance, 499)
+
+
+    def test_more_periods(self):
+        self.sim.mint(self.sim.actors[0], 1024)
+        self.sim.mint(self.sim.actors[1], 1024)
+        self.sim.next()
+
+        self.sim.mint(self.sim.actors[0], 1024)
+        self.sim.next()
+
+        balance = self.sim.balance(self.sim.actors[0])
+        self.assertEqual(balance, 2047)
+
+
+    def test_demurrage(self):
+        self.sim.mint(self.sim.actors[0], self.sim.from_units(100))
+        self.sim.mint(self.sim.actors[1], self.sim.from_units(100))
+        self.sim.transfer(self.sim.actors[0], self.sim.actors[2], self.sim.from_units(10))
+        self.sim.next()
+
+        balance = self.sim.balance(self.sim.actors[0])
+        self.assertEqual(balance, 90005520)
+        
+        balance = self.sim.balance(self.sim.actors[1])
+        self.assertEqual(balance, 99995000)
+
+        balance = self.sim.balance(self.sim.actors[1], base=True)
+        self.assertEqual(balance, 100000000)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/sim/tests_sim_limit.py

@@ -0,0 +1,35 @@
+# standard imports
+import unittest
+import logging
+
+# local imports
+from erc20_demurrage_token import DemurrageTokenSettings
+from erc20_demurrage_token.sim import (
+        DemurrageTokenSimulation,
+        TxLimitException,
+        )
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+class TestLimit(unittest.TestCase):
+
+    def setUp(self):
+        self.cap = 0
+        settings = DemurrageTokenSettings()
+        settings.name = 'Simulated Demurrage Token'
+        settings.symbol = 'SIM'
+        settings.decimals = 6
+        settings.demurrage_level = 1
+        settings.period_minutes = 1
+        self.sim = DemurrageTokenSimulation('evm:foochain:42', settings, redistribute=True, cap=self.cap, actors=1)
+
+
+    def test_limit(self):
+        with self.assertRaises(TxLimitException):
+            for i in range(60):
+                self.sim.mint(self.sim.actors[0], i)
+        
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_amounts.py

@@ -0,0 +1,123 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+class TestAmounts(TestDemurrageDefault):
+
+    def test_mints(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1000)
+        r = self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+        
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, 980)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1000)
+        r = self.rpc.do(o)
+
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within_lower(balance, 1980, 750)
+
+        self.backend.time_travel(self.start_time + self.period_seconds * 2)
+
+        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+        
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+
+        expected_balance = ((1 - self.tax_level / 1000000) ** 10) * 1000
+        expected_balance += ((1 - self.tax_level / 1000000) ** 20) * 1000
+        #self.assert_within_lower(balance, expected_balance, 500)
+        self.assertEqual(balance, 1940)
+
+    def test_transfers(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 2000)
+        r = self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+ 
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, 1960)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.accounts[1], self.accounts[2], 500)
+        r = self.rpc.do(o)
+     
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, 1460)
+
+        o = c.balance_of(self.address, self.accounts[2], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within_lower(balance, 500, 2000)
+
+
+    def test_dynamic_amount(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 2000)
+        r = self.rpc.do(o)
+
+        cases = [
+            (60, 1960),
+            (120, 1920),
+            (180, 1882),
+            (240, 1844),
+            (300, 1807),
+            (360, 1771),
+            (420, 1736),
+            (480, 1701),
+            (540, 1667),
+            (600, 1634),
+                ]
+        for case in cases:
+            self.backend.time_travel(self.start_time + int(case[0] * (self.period_seconds / 60)))
+
+            o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance = c.parse_balance(r)
+            self.assert_within_lower(balance, case[1], 10000)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_basic.py

@@ -9,12 +9,16 @@ import datetime
 from chainlib.eth.constant import ZERO_ADDRESS
 from chainlib.eth.nonce import RPCNonceOracle
 from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
 
 # local imports
 from erc20_demurrage_token import DemurrageToken
 
 # test imports
-from tests.base import TestDemurrageDefault
+from erc20_demurrage_token.unittest import TestDemurrageDefault
 
 logging.basicConfig(level=logging.DEBUG)
 logg = logging.getLogger()
@@ -35,8 +39,24 @@ class TestBasic(TestDemurrageDefault):
         r = self.rpc.do(o)
 
 
-    def test_apply_demurrage(self):
-        modifier = 10 * (10 ** 37)
+    def test_balance(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertEqual(balance, 1024)
+
+
+    def test_apply_demurrage_limited(self):
+        #modifier = (10 ** 28)
+        modifier = 1
 
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
@@ -46,23 +66,64 @@ class TestBasic(TestDemurrageDefault):
         demurrage_amount = c.parse_demurrage_amount(r)
         self.assertEqual(modifier, demurrage_amount)
 
-        self.backend.time_travel(self.start_time + self.period_seconds - 1)
+        self.backend.time_travel(self.start_time + (60 * 43200))
+        (tx_hash, o) = c.apply_demurrage(self.address, sender_address=self.accounts[0], limit=20000)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.demurrage_amount(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        demurrage_amount = c.parse_demurrage_amount(r)
+        self.assert_equal_decimals(0.9906, demurrage_amount, 4)
+
+
+    def test_apply_demurrage(self):
+        #modifier = (10 ** 28)
+        modifier = 1
+
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
         o = c.demurrage_amount(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         demurrage_amount = c.parse_demurrage_amount(r)
         self.assertEqual(modifier, demurrage_amount)
 
-        self.backend.time_travel(self.start_time + self.period_seconds + 1)
+        o = block_latest()
+        r = self.rpc.do(o)
+        o = block_by_number(r)
+        b = self.rpc.do(o)
+        logg.debug('block {} start {}'.format(b['timestamp'], self.start_time))
+
+        self.backend.time_travel(self.start_time + (60 * 43200))
         (tx_hash, o) = c.apply_demurrage(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
         o = c.demurrage_amount(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         demurrage_amount = c.parse_demurrage_amount(r)
-        modifier = int(98 * (10 ** 36))
-        self.assertEqual(modifier, demurrage_amount)
+        self.assert_equal_decimals(0.98, demurrage_amount, 2)
+
+        self.backend.time_travel(self.start_time + (60 * 43200 * 2))
+        (tx_hash, o) = c.apply_demurrage(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        o = c.demurrage_amount(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        demurrage_amount = c.parse_demurrage_amount(r)
+        modifier_base = 1000000 - self.tax_level
+        modifier = int(modifier_base * (10 ** 22)) # 38 decimal places minus 6 (1000000)
+        self.assert_equal_decimals(0.9604, demurrage_amount, 4)
 
 
-    def test_mint(self):
+    def test_mint_balance(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
         (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
@@ -81,16 +142,19 @@ class TestBasic(TestDemurrageDefault):
         o = receipt(tx_hash)
         r = self.rpc.do(o)
         self.assertEqual(r['status'], 1)
-
         o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
         r = self.rpc.do(o)
         balance = c.parse_balance_of(r)
         self.assertEqual(balance, 2000)
 
 
-        self.backend.time_travel(self.start_time + 61)
+        self.backend.time_travel(self.start_time + (60 * 43200))
         (tx_hash, o) = c.apply_demurrage(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
         o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
         r = self.rpc.do(o)
         balance = c.parse_balance_of(r)
@@ -155,7 +219,7 @@ class TestBasic(TestDemurrageDefault):
         (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
         self.rpc.do(o)
 
-        self.backend.time_travel(self.start_time + 61)
+        self.backend.time_travel(self.start_time + (60 * 43200))
         (tx_hash, o) = c.apply_demurrage(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         o = c.to_base_amount(self.address, 1000, sender_address=self.accounts[0])
@@ -197,7 +261,52 @@ class TestBasic(TestDemurrageDefault):
         r = self.rpc.do(o)
         self.assertEqual(r['status'], 1)
 
-       
+      
+    def test_approve(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 500)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+ 
+        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 600)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 0)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 600)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.increase_allowance(self.address, self.accounts[0], self.accounts[1], 200)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.decrease_allowance(self.address, self.accounts[0], self.accounts[1], 800)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 42)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
 
     def test_transfer_from(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
@@ -236,6 +345,12 @@ class TestBasic(TestDemurrageDefault):
         balance = c.parse_balance_of(r)
         self.assertEqual(balance, 500)
 
+        (tx_hash, o) = c.transfer_from(self.address, self.accounts[2], self.accounts[1], self.accounts[3], 1)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
 
 if __name__ == '__main__':
     unittest.main()

python/tests/test_cap.py

@@ -18,7 +18,7 @@ from hexathon import (
 from erc20_demurrage_token import DemurrageToken
 
 # test imports
-from tests.base import TestDemurrageCap
+from erc20_demurrage_token.unittest import TestDemurrageDefault
 
 logging.basicConfig(level=logging.DEBUG)
 logg = logging.getLogger()
@@ -26,18 +26,27 @@ logg = logging.getLogger()
 testdir = os.path.dirname(__file__)
 
 
-class TestCap(TestDemurrageCap):
+class TestCap(TestDemurrageDefault):
 
-    def test_cap_set(self):
+    def test_cap(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        o = c.supply_cap(self.address, sender_address=self.accounts[0])
+
+        o = c.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        logg.debug('r {}'.format(r))
+
+        (tx_hash, o) = c.set_max_supply(self.address, self.accounts[0], self.default_supply_cap)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.max_supply(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         cap = c.parse_supply_cap(r)
         self.assertEqual(cap, self.default_supply_cap)
 
-
-    def test_cap(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
         (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], self.default_supply_cap)
@@ -53,15 +62,5 @@ class TestCap(TestDemurrageCap):
         self.assertEqual(r['status'], 0)
 
 
-    def test_cap_first(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], self.default_supply_cap + 1)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 0)
-
-
 if __name__ == '__main__':
     unittest.main()

python/tests/test_expiry.py

@@ -0,0 +1,98 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+import datetime
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+class TestExpire(TestDemurrageDefault):
+
+    def test_expires(self):
+        mint_amount = self.default_supply
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        for i in range(3):
+            (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[i+1], mint_amount)
+            r = self.rpc.do(o)
+
+        (tx_hash, o) = c.set_expire_period(self.address, self.accounts[0], 2)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.expires(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        expiry_time = c.parse_expires(r)
+
+        self.backend.time_travel(expiry_time + 60)
+        o = block_latest()
+        r = self.rpc.do(o)
+        o = block_by_number(r)
+        r = self.rpc.do(o)
+        self.assertGreaterEqual(r['timestamp'], expiry_time)
+        
+        nonce_oracle = RPCNonceOracle(self.sink_address, self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[2], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[2], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within(balance, 0.9604 * mint_amount, 1)
+
+        o = c.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        supply = c.parse_balance(r)
+
+        (tx_hash, o) = c.change_period(self.address, self.sink_address)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+
+        o = c.decay_by(self.address, supply, int((expiry_time - self.start_time) / 60), sender_address=self.sink_address)
+        r = self.rpc.do(o)
+        target_balance = c.parse_balance(r)
+
+        self.assert_within_lower(balance, supply - target_balance, 0.0001)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_growth.py

@@ -0,0 +1,66 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+import datetime
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+class TestGrowth(TestDemurrageDefault):
+
+    def test_decay_by(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        v = 1000000000
+        o = c.decay_by(self.address, v, 20000, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        g = c.parse_decay_by(r)
+        self.assertEqual(int(g), 990690498)
+       
+        o = c.decay_by(self.address, v, 43200, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        g = c.parse_decay_by(r)
+        self.assertEqual(int(g), 980000000)
+
+
+    def test_decay_steps(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        v = 1000000000
+        o = c.decay_by(self.address, v, 43200, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        gr = c.parse_decay_by(r)
+
+        v = 1000000000
+        for i in range(100):
+            o = c.decay_by(self.address, v, 432, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            v = c.parse_decay_by(r)
+
+        self.assert_within_lower(int(v), int(gr), 0.1)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_period.py

@@ -7,13 +7,25 @@ import logging
 # external imports
 from chainlib.eth.constant import ZERO_ADDRESS
 from chainlib.eth.nonce import RPCNonceOracle
-from chainlib.eth.tx import receipt
+from chainlib.eth.tx import (
+        receipt,
+        TxFactory,
+        TxFormat,
+        )
+from chainlib.eth.contract import (
+        ABIContractEncoder,
+        ABIContractType,
+        )
+from hexathon import same as hex_same
+from hexathon import strip_0x
+from dexif import from_fixed
 
 # local imports
 from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token import DemurrageRedistribution
 
 # test imports
-from tests.base import TestDemurrageDefault
+from erc20_demurrage_token.unittest import TestDemurrageDefault
 
 logging.basicConfig(level=logging.DEBUG)
 logg = logging.getLogger()
@@ -22,6 +34,55 @@ testdir = os.path.dirname(__file__)
 
 class TestPeriod(TestDemurrageDefault):
 
+    def test_period_and_amount(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        for i in range(100):
+            self.backend.time_travel(self.start_time + int((self.period_seconds / 100) * (i + 1)))
+            (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0], 0)
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+        for lg in r['logs']:
+            if hex_same(lg['topics'][0], '1c9c74563c32efd114cb36fb5e432d9386c8254d08456614804a33a3088ab736'):
+                self.assert_equal_decimals(0.98, from_fixed(strip_0x(lg['data'])), 2)
+
+
+    def test_period_demurrage(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1024)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        self.backend.time_travel(self.start_time + self.period_seconds + int(self.period_seconds / 2))
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        for lg in r['logs']:
+            if hex_same(lg['topics'][0], '1c9c74563c32efd114cb36fb5e432d9386c8254d08456614804a33a3088ab736'):
+                self.assert_equal_decimals(0.9701, from_fixed(strip_0x(lg['data'])), 4)
+
+        o = c.redistributions(self.address, 1, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        redistribution_data = c.parse_redistributions(r)
+        redistribution = DemurrageRedistribution(redistribution_data)
+        logg.debug('fixxx {}'.format(redistribution.demurrage))
+
+
     def test_period(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
@@ -31,7 +92,7 @@ class TestPeriod(TestDemurrageDefault):
         r = self.rpc.do(o)
         self.assertEqual(r['status'], 1)
 
-        self.backend.time_travel(self.start_time + 61)
+        self.backend.time_travel(self.start_time + self.period_seconds)
 
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
         (tx_hash, o) = c.change_period(self.address, self.accounts[0])
@@ -49,20 +110,128 @@ class TestPeriod(TestDemurrageDefault):
         period = c.parse_to_redistribution_period(r)
         self.assertEqual(2, period)
 
-        o = c.redistributions(self.address, 1, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        redistribution = c.parse_redistributions(r)
-
-        o = c.to_redistribution_period(self.address, redistribution, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        period = c.parse_to_redistribution_period(r)
-        self.assertEqual(2, period)
-
         o = c.actual_period(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         period = c.parse_actual_period(r)
         self.assertEqual(2, period)
 
+        o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        period = from_fixed(r)
+        redistro = DemurrageRedistribution(redistribution)
+        logg.debug('redistro {} {}'.format(redistro, period))
+
+        self.backend.time_travel(self.start_time + self.period_seconds * 2)
+
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.redistributions(self.address, 2, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        redistribution = c.parse_redistributions(r)
+
+        o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        period = from_fixed(r)
+
+        # allow test code float rounding error to billionth
+        modifier = (1 - (self.tax_level / 1000000)) ** ((self.period_seconds * 2) / 60)
+        modifier *= 10 ** 9 
+        modifier = int(modifier) * (10 ** (28 - 9))
+
+        period /= (10 ** (28 - 9))
+        period = int(period) * (10 ** (28 - 9))
+        self.assertEqual(modifier, period)
+
+
+    def test_change_sink(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        o = c.balance_of(self.address, ZERO_ADDRESS, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertEqual(balance, 0)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 102400000000)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        self.backend.time_travel(self.start_time + self.period_seconds + 1)
+
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertGreater(balance, 0)
+        old_sink_balance = balance
+
+        o = c.balance_of(self.address, self.accounts[3], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertEqual(balance, 0)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[5], self.rpc)
+        c = TxFactory(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        enc = ABIContractEncoder()
+        enc.method('setSinkAddress')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.address(self.accounts[3])
+        data = enc.get()
+        o = c.template(self.accounts[5], self.address, use_nonce=True)
+        o = c.set_code(o, data)
+        (tx_hash, o) = c.finalize(o, TxFormat.JSONRPC)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = TxFactory(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        enc = ABIContractEncoder()
+        enc.method('setSinkAddress')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.address(self.accounts[3])
+        data = enc.get()
+        o = c.template(self.accounts[0], self.address, use_nonce=True)
+        o = c.set_code(o, data)
+        (tx_hash, o) = c.finalize(o, TxFormat.JSONRPC)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        self.backend.time_travel(self.start_time + (self.period_seconds * 2) + 1)
+
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertLess(balance, old_sink_balance)
+
+        o = c.balance_of(self.address, self.accounts[3], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance_of(r)
+        self.assertGreater(balance, 0)
+
 
 if __name__ == '__main__':
     unittest.main()

python/tests/test_pure.py

@@ -1,70 +0,0 @@
-# standard imports
-import os
-import unittest
-import json
-import logging
-import math
-
-# external imports
-from chainlib.eth.constant import ZERO_ADDRESS
-from chainlib.eth.nonce import RPCNonceOracle
-from chainlib.eth.tx import receipt
-from chainlib.error import JSONRPCException
-import eth_tester
-
-# local imports
-from erc20_demurrage_token import DemurrageToken
-
-# test imports
-from tests.base import TestDemurrageDefault
-
-logging.basicConfig(level=logging.DEBUG)
-logg = logging.getLogger()
-
-testdir = os.path.dirname(__file__)
-
-
-class Test(TestDemurrageDefault):
-
-    def test_fractional_state(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-
-        with self.assertRaises(JSONRPCException):
-            o = c.remainder(self.address, 2, 1, sender_address=self.accounts[0])
-            self.rpc.do(o)
- 
-        with self.assertRaises(JSONRPCException):
-            o = c.remainder(self.address, 0, 100001, sender_address=self.accounts[0])
-            self.rpc.do(o)       
-
-        o = c.remainder(self.address, 1, 2, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        remainder = c.parse_remainder(r)
-        self.assertEqual(remainder, 0);
-
-        whole = 5000001
-        parts = 20000
-        expect = whole - (math.floor(whole/parts) * parts) 
-        o = c.remainder(self.address, parts, whole, sender_address=self.accounts[0])
-        r = self.rpc.do(o)      
-        remainder = c.parse_remainder(r)
-        self.assertEqual(remainder, expect)
-
-        parts = 30000
-        expect = whole - (math.floor(whole/parts) * parts) 
-        o = c.remainder(self.address, parts, whole, sender_address=self.accounts[0])
-        r = self.rpc.do(o)      
-        remainder = c.parse_remainder(r)
-        self.assertEqual(remainder, expect)
-
-        parts = 40001
-        expect = whole - (math.floor(whole/parts) * parts) 
-        o = c.remainder(self.address, parts, whole, sender_address=self.accounts[0])
-        r = self.rpc.do(o)      
-        remainder = c.parse_remainder(r)
-        self.assertEqual(remainder, expect)
-
-
-if __name__ == '__main__':
-    unittest.main()

python/tests/test_redistribution.py

@@ -1,263 +0,0 @@
-# standard imports
-import os
-import unittest
-import json
-import logging
-
-# external imports
-from chainlib.eth.constant import ZERO_ADDRESS
-from chainlib.eth.nonce import RPCNonceOracle
-from chainlib.eth.tx import receipt
-from chainlib.eth.block import block_latest
-from chainlib.eth.address import to_checksum_address
-from hexathon import (
-        strip_0x,
-        add_0x,
-        )
-
-# local imports
-from erc20_demurrage_token import DemurrageToken
-
-# test imports
-from tests.base import TestDemurrageDefault
-
-logging.basicConfig(level=logging.DEBUG)
-logg = logging.getLogger()
-
-testdir = os.path.dirname(__file__)
-
-
-class TestRedistribution(TestDemurrageDefault):
-
-    def test_debug_periods(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-
-        o = c.actual_period(self.address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        pactual = c.parse_actual_period(r)
-
-        o = c.period_start(self.address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        pstart = c.parse_actual_period(r)
-
-        o = c.period_duration(self.address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        pduration = c.parse_actual_period(r)
-
-        o = block_latest()
-        blocknumber = self.rpc.do(o)
-
-        logg.debug('actual {} start {} duration {} blocknumber {}'.format(pactual, pstart, pduration, blocknumber))
-
-
-    # TODO: check receipt log outputs
-    def test_redistribution_storage(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        o = c.redistributions(self.address, 0, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        self.assertEqual(strip_0x(r), '000000000000000000000000f424000000000000000000000000000000000001')
-
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], 1000000)
-        r = self.rpc.do(o)
-
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[2], 1000000)
-        r = self.rpc.do(o)
-
-        external_address = to_checksum_address('0x' + os.urandom(20).hex())
-
-        nonce_oracle = RPCNonceOracle(self.accounts[2], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[2], external_address, 1000000)
-        r = self.rpc.do(o)
-
-        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[1], external_address, 999999)
-        r = self.rpc.do(o)
-
-        self.backend.time_travel(self.start_time + self.period_seconds + 1)
-
-        o = c.redistributions(self.address, 0, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        self.assertEqual(strip_0x(r), '000000000000000000000000f42400000000010000000000001e848000000001')
-
-        o = c.redistributions(self.address, 0, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        self.assertEqual(strip_0x(r), '000000000000000000000000f42400000000010000000000001e848000000001')
-
-
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[0], 1000000)
-        r = self.rpc.do(o)
-
-        o = c.redistributions(self.address, 1, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        self.assertEqual(strip_0x(r), '000000000000000000000000ef4200000000000000000000002dc6c000000002')
-
-
-    def test_redistribution_balance_on_zero_participants(self):
-        supply = self.default_supply
-
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], supply)
-        r = self.rpc.do(o)
-
-        self.backend.time_travel(self.start_time + self.period_seconds + 1)
-        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[0])
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        rcpt = self.rpc.do(o)
-        self.assertEqual(rcpt['status'], 1)
-
-        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        o = c.total_supply(self.address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        total_supply = c.parse_total_supply(r)
-        sink_increment = int(total_supply * (self.tax_level / 1000000))
-        self.assertEqual(supply, total_supply)
-
-        for l in rcpt['logs']:
-            if l['topics'][0] == '0xa0717e54e02bd9829db5e6e998aec0ae9de796b8d150a3cc46a92ab869697755': # event Decayed(uint256,uint256,uint256,uint256)
-                period = int.from_bytes(bytes.fromhex(strip_0x(l['topics'][1])), 'big')
-                self.assertEqual(period, 2)
-                b = bytes.fromhex(strip_0x(l['data']))
-                remainder = int.from_bytes(b, 'big')
-                self.assertEqual(remainder, int((1000000 - self.tax_level) * (10 ** 32)))
-
-        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        sink_balance = c.parse_balance_of(r)
-
-        self.assertEqual(sink_balance, int(sink_increment * 0.98))
-        self.assertEqual(sink_balance, int(sink_increment * (1000000 - self.tax_level) / 1000000))
-
-        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        balance = c.parse_balance_of(r)
-        self.assertEqual(balance, supply - sink_increment)
-
-
-    def test_redistribution_two_of_ten(self):
-        mint_amount = 100000000
-        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        z = 0
-        for i in range(10):
-            (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[i], mint_amount)
-            self.rpc.do(o)
-            z += mint_amount
-
-        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        initial_balance = c.parse_balance_of(r)
-
-        spend_amount = 1000000
-        external_address = to_checksum_address('0x' + os.urandom(20).hex())
-
-        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[1], external_address, spend_amount)
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        nonce_oracle = RPCNonceOracle(self.accounts[2], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[2], external_address, spend_amount)
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        # No cheating!
-        nonce_oracle = RPCNonceOracle(self.accounts[3], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[3], self.accounts[3], spend_amount)
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        # No cheapskating!
-        nonce_oracle = RPCNonceOracle(self.accounts[4], self.rpc)
-        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[4], external_address, spend_amount-1)
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-
-        self.backend.time_travel(self.start_time + self.period_seconds + 1)
-
-        (tx_hash, o) = c.apply_demurrage(self.address, self.accounts[4])
-        self.rpc.do(o)
-
-        (tx_hash, o) = c.change_period(self.address, self.accounts[4])
-        self.rpc.do(o)
-
-        o = c.balance_of(self.address, self.accounts[3], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        bummer_balance = c.parse_balance_of(r)
-
-        self.assertEqual(bummer_balance, mint_amount - (mint_amount * (self.tax_level / 1000000)))
-        logg.debug('bal {} '.format(bummer_balance))
-
-        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        bummer_balance = c.parse_balance_of(r)
-        spender_balance = mint_amount - spend_amount
-        spender_decayed_balance = int(spender_balance - (spender_balance * (self.tax_level / 1000000)))
-        self.assertEqual(bummer_balance, spender_decayed_balance)
-        logg.debug('bal {} '.format(bummer_balance))
-
-        (tx_hash, o) = c.apply_redistribution_on_account(self.address, self.accounts[4], self.accounts[1])
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-#        logg.debug('log {}'.format(r.logs))
-        (tx_hash, o) = c.apply_redistribution_on_account(self.address, self.accounts[4], self.accounts[2])
-        self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        o = c.redistributions(self.address, 0, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        redistribution_data = c.parse_redistributions(r)
-        logg.debug('redist data {}'.format(redistribution_data))
-
-        o = c.account_period(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        account_period_data = c.parse_account_period(r)
-        logg.debug('account period {}'.format(account_period_data))
-
-        o = c.actual_period(self.address, sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        actual_period = c.parse_actual_period(r)
-        logg.debug('period {}'.format(actual_period))
-
-        redistribution = int((z / 2) * (self.tax_level / 1000000))
-        spender_new_base_balance = ((mint_amount - spend_amount) + redistribution)
-        spender_new_decayed_balance = int(spender_new_base_balance - (spender_new_base_balance * (self.tax_level / 1000000)))
-
-        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        spender_actual_balance = c.parse_balance_of(r)
-        logg.debug('rrr {} {}'.format(redistribution, spender_new_decayed_balance))
-
-        self.assertEqual(spender_actual_balance, spender_new_decayed_balance)
-
-

python/tests/test_redistribution_single.py

@@ -0,0 +1,205 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        )
+from chainlib.eth.address import to_checksum_address
+from hexathon import (
+        strip_0x,
+        add_0x,
+        same as hex_same,
+        )
+from dexif import from_fixed
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+class TestRedistribution(TestDemurrageDefault):
+
+
+    def test_redistribution_periods(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
+        supply = self.default_supply
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[0], supply)
+        self.rpc.do(o)
+
+        for i in range(1, 100):
+            logg.info('execute time travel to period {}'.format(i))
+            self.backend.time_travel(self.start_time + (self.period_seconds * i))
+            (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            redistribution_value = 0
+            for lg in r['logs']:
+                if hex_same(lg['topics'][0], '0x9a2a887706623ad3ff7fc85652deeceabe9fe1e00466c597972079ee91ea40d3'):
+                    redistribution_value = int(strip_0x(lg['data']), 16)
+
+            o = c.redistributions(self.address, i, sender_address=self.accounts[0])
+            redistribution = self.rpc.do(o)
+
+            o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            demurrage = from_fixed(r)
+
+            o = c.redistributions(self.address, i-1, sender_address=self.accounts[0])
+            redistribution = self.rpc.do(o)
+
+            o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            demurrage_previous = from_fixed(r)
+
+            o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance_sink = c.parse_balance(r)
+
+            o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance_minter = c.parse_balance(r)
+
+            logg.info('testing redistro {} sink {} mint {} adds up to {} supply {} with demurrage between {} and {}'.format(redistribution_value, balance_sink, balance_minter, balance_sink + balance_minter, supply, demurrage_previous, demurrage))
+
+            self.assert_within(balance_minter + balance_sink, supply, 10)
+
+
+    def test_redistribution_catchup_periods(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
+        supply = self.default_supply
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[0], supply)
+        self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + (self.period_seconds * 100))
+
+        balance_minter = None
+        balance_sink = None
+        real_supply = None
+
+        for i in range(1, 101):
+            (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance_sink = c.parse_balance(r)
+
+            o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance_minter = c.parse_balance(r)
+            
+            real_supply = balance_sink + balance_minter
+            logg.info('period {} testing sink {} mint {} adds up to supply {} of original {} (delta {})'.format(i, balance_sink, balance_minter, real_supply, supply, supply - real_supply))
+
+        i = 100
+        o = c.redistributions(self.address, i, sender_address=self.accounts[0])
+        redistribution = self.rpc.do(o)
+
+        o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        demurrage = c.parse_to_redistribution_item(r)
+
+        o = c.redistributions(self.address, i-1, sender_address=self.accounts[0])
+        redistribution = self.rpc.do(o)
+
+        o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        demurrage_previous = c.parse_to_redistribution_item(r)
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance_sink = c.parse_balance(r)
+
+        o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance_minter = c.parse_balance(r)
+
+        logg.debug('testing sink {} mint {} adds up to supply {} with demurrage between {} and {}'.format(balance_sink, balance_minter, real_supply, demurrage_previous, demurrage))
+
+        self.assert_within_lower(balance_minter + balance_sink, supply, 0.1)
+
+
+#    def test_redistribution_boundaries(self):
+#        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+#        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+#
+#        demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
+#        supply = self.default_supply
+#
+#        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[0], supply)
+#        self.rpc.do(o)
+#
+#        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+#        r = self.rpc.do(o)
+#        balance = c.parse_balance(r)
+#        logg.debug('balance before {} supply {}'.format(balance, supply))
+#
+#        self.backend.time_travel(self.start_time + self.period_seconds)
+#        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+#        r = self.rpc.do(o)
+#
+#        o = receipt(tx_hash)
+#        r = self.rpc.do(o)
+#        self.assertEqual(r['status'], 1)
+#
+#        o = c.redistributions(self.address, 1, sender_address=self.accounts[0])
+#        r = self.rpc.do(o)
+#        oo = c.to_redistribution_supply(self.address, r, sender_address=self.accounts[0])
+#        rr = self.rpc.do(oo)
+#        oo = c.to_redistribution_demurrage_modifier(self.address, r, sender_address=self.accounts[0])
+#        rr = self.rpc.do(oo)
+#
+#        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+#        r = self.rpc.do(o)
+#        balance = c.parse_balance(r)
+#
+#        self.backend.time_travel(self.start_time + self.period_seconds * 2 + 1)
+#        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+#        r = self.rpc.do(o)
+#
+#        o = receipt(tx_hash)
+#        r = self.rpc.do(o)
+#        self.assertEqual(r['status'], 1)
+#
+#        o = c.redistributions(self.address, 2, sender_address=self.accounts[0])
+#        r = self.rpc.do(o)
+#        oo = c.to_redistribution_supply(self.address, r, sender_address=self.accounts[0])
+#        rr = self.rpc.do(oo)
+#        oo = c.to_redistribution_demurrage_modifier(self.address, r, sender_address=self.accounts[0])
+#        rr = self.rpc.do(oo)
+#
+#        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+#        r = self.rpc.do(o)
+#        balance = c.parse_balance(r)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_redistribution_unit.py

@@ -0,0 +1,202 @@
+import os
+import unittest
+import json
+import logging
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        )
+from chainlib.eth.address import to_checksum_address
+from hexathon import (
+        strip_0x,
+        add_0x,
+        )
+from dexif import to_fixed
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token import DemurrageRedistribution
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+class TestRedistribution(TestDemurrageDefault):
+
+
+    # TODO: move to "pure" test file when getdistribution is implemented in all contracts
+    def test_distribution_direct(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
+        supply = self.default_supply
+
+        #o = c.get_distribution(self.address, supply, demurrage, sender_address=self.accounts[0])
+        o = c.get_distribution(self.address, supply, to_fixed(self.tax_level / 1000000), sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        distribution = c.parse_get_distribution(r)
+        expected_distribution = self.default_supply * (self.tax_level / 1000000)
+        self.assert_within(distribution, expected_distribution, 100)
+
+
+    def test_distribution_from_redistribution(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        demurrage = (1 - (self.tax_level / 100000)) * (10**28)
+
+        supply = self.default_supply
+
+        o = c.to_redistribution(self.address, 0, to_fixed(self.tax_level / 1000000), supply, 2, sender_address=self.accounts[0])
+        redistribution = self.rpc.do(o)
+
+        o = c.get_distribution_from_redistribution(self.address, redistribution, self.accounts[0])
+        r = self.rpc.do(o)
+        distribution = c.parse_get_distribution(r)
+        expected_distribution = (self.default_supply * (self.tax_level / 1000000))
+        logg.debug('distribution {} supply {}'.format(distribution, self.default_supply))
+        self.assert_within(distribution, expected_distribution, 1000)
+
+
+    def test_single_step_basic(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        mint_amount = 100000000
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], mint_amount)
+        self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        self.rpc.do(o)
+
+        expected_balance = int(mint_amount - ((self.tax_level / 1000000) * mint_amount))
+
+        o = c.balance_of(self.address, ZERO_ADDRESS, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+
+        logg.debug('balance {}'.format(balance))
+
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+
+        self.assertEqual(balance, expected_balance)
+
+
+    def test_single_step_multi(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        mint_amount = 100000000
+
+        for i in range(3):
+            (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[i+1], mint_amount)
+            self.rpc.do(o)
+    
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        (tx_hash, o) = c.change_period(self.address, self.accounts[0])
+        self.rpc.do(o)
+
+        expected_balance = int(mint_amount - ((self.tax_level / 1000000) * mint_amount))
+
+        for i in range(3):
+            o = c.balance_of(self.address, self.accounts[i+1], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            balance = c.parse_balance(r)
+            self.assertEqual(balance, expected_balance)
+
+
+    def test_single_step_transfer(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        mint_amount = self.default_supply
+        half_mint_amount = int(mint_amount / 2)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], mint_amount)
+        self.rpc.do(o)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[2], mint_amount)
+        self.rpc.do(o)
+    
+        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.accounts[1], self.accounts[3], half_mint_amount)
+        self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        (tx_hash, o) = c.change_period(self.address, self.accounts[1])
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        # check that we have crossed into new period, this will throw if not
+        o = c.redistributions(self.address, 1, sender_address=self.accounts[0])
+        self.rpc.do(o)
+
+        demurrage_amount = int((self.tax_level / 1000000) * mint_amount)
+
+        expected_balance = mint_amount - demurrage_amount
+        o = c.balance_of(self.address, self.accounts[2], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within(balance, expected_balance, 10)
+
+        half_demurrage_amount = int((self.tax_level / 1000000) * half_mint_amount)
+
+        expected_balance = half_mint_amount - half_demurrage_amount
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, expected_balance)
+
+        o = c.balance_of(self.address, self.accounts[3], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, expected_balance)
+
+        o = c.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        supply = c.parse_total_supply(r)
+
+        o = c.redistributions(self.address, 0, sender_address=self.accounts[0])
+        redistribution = self.rpc.do(o)
+        o = c.to_redistribution_supply(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        supply = c.parse_to_redistribution_item(r)
+        o = c.to_redistribution_demurrage_modifier(self.address, redistribution, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        #demurrage = c.parse_to_redistribution_item(r)
+        #logg.debug('\nrediistribution {}\ndemurrage {}\nsupply {}'.format(redistribution, demurrage, supply))
+        redistro_item = DemurrageRedistribution(redistribution)
+        logg.debug('redistribution {}'.format(redistro_item))
+
+        expected_balance = int(supply * (self.tax_level / 1000000))
+        expected_balance_tolerance = 1
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within_lower(balance, expected_balance, 1000)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_seal.py

@@ -0,0 +1,195 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+import datetime
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token.seal import ContractState
+from erc20_demurrage_token.seal import CONTRACT_SEAL_STATE_MAX
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+
+class TestSeal(TestDemurrageDefault):
+
+    def test_seal_dup(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+
+    def test_seal_all(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], CONTRACT_SEAL_STATE_MAX)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.is_sealed(self.address, 0, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertTrue(c.parse_is_sealed(r))
+
+
+    def test_seal_minter(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+    
+        (tx_hash, o) = c.add_minter(self.address, self.accounts[0], self.accounts[1])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], ContractState.MINTER_STATE)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.add_minter(self.address, self.accounts[0], self.accounts[2])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        o = c.is_sealed(self.address, ContractState.MINTER_STATE, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertTrue(c.parse_is_sealed(r))
+
+
+    def test_seal_expiry(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+    
+        (tx_hash, o) = c.set_expire_period(self.address, self.accounts[0], 10)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_expire_period(self.address, self.accounts[0], 20)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], ContractState.EXPIRY_STATE)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_expire_period(self.address, self.accounts[0], 21)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        o = c.is_sealed(self.address, ContractState.EXPIRY_STATE, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertTrue(c.parse_is_sealed(r))
+
+
+    def test_seal_set_sink_address(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+    
+        (tx_hash, o) = c.set_sink_address(self.address, self.accounts[0], self.accounts[3])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_sink_address(self.address, self.accounts[0], self.accounts[4])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], ContractState.SINK_STATE)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_sink_address(self.address, self.accounts[0], self.accounts[5])
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        o = c.is_sealed(self.address, ContractState.SINK_STATE, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertTrue(c.parse_is_sealed(r))
+
+
+    def test_seal_cap(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+    
+        (tx_hash, o) = c.set_max_supply(self.address, self.accounts[0], 100)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_max_supply(self.address, self.accounts[0], 200)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.seal(self.address, self.accounts[0], ContractState.CAP_STATE)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.set_max_supply(self.address, self.accounts[0], 300)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 0)
+
+        o = c.is_sealed(self.address, ContractState.CAP_STATE, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertTrue(c.parse_is_sealed(r))
+
+
+if __name__ == '__main__':
+    unittest.main()
+
+

python/tests/test_single.py

@@ -13,12 +13,13 @@ from hexathon import (
         strip_0x,
         add_0x,
         )
+from dexif import to_fixed
 
 # local imports
 from erc20_demurrage_token import DemurrageToken
 
 # test imports
-from tests.base import TestDemurrageSingle
+from erc20_demurrage_token.unittest import TestDemurrageDefault
 
 logging.basicConfig(level=logging.DEBUG)
 logg = logging.getLogger()
@@ -26,10 +27,9 @@ logg = logging.getLogger()
 testdir = os.path.dirname(__file__)
 
 
-class TestRedistributionSingle(TestDemurrageSingle):
+class TestRedistributionSingle(TestDemurrageDefault):
 
     def test_single_even_if_multiple(self):
-
         mint_amount = 100000000
 
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
@@ -63,22 +63,23 @@ class TestRedistributionSingle(TestDemurrageSingle):
         r = self.rpc.do(o)
         self.assertEqual(r['status'], 1)
 
+        tax_modifier = 0.98
         o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
         r = self.rpc.do(o)
-        balance = c.parse_balance_of(r)
-        self.assertEqual(balance, mint_amount - (mint_amount * (self.tax_level / 1000000)))
+        balance = c.parse_balance(r)
+        self.assertEqual(balance, int(mint_amount * tax_modifier))
 
         o = c.balance_of(self.address, self.accounts[2], sender_address=self.accounts[0])
         r = self.rpc.do(o)
-        balance = c.parse_balance_of(r)
+        balance = c.parse_balance(r)
         base_amount = mint_amount - int(mint_amount * 0.1)
-        self.assertEqual(balance, (base_amount - (base_amount * (self.tax_level / 1000000))))
+        self.assertEqual(balance, int(base_amount * tax_modifier)) #(base_amount - (base_amount * (self.tax_level / 1000000))))
 
         o = c.balance_of(self.address, self.accounts[3], sender_address=self.accounts[0])
         r = self.rpc.do(o)
-        balance = c.parse_balance_of(r)
+        balance = c.parse_balance(r)
         base_amount = mint_amount - int(mint_amount * 0.2)
-        self.assertEqual(balance, (base_amount - (base_amount * (self.tax_level / 1000000))))
+        self.assertEqual(balance, int(base_amount * tax_modifier)) #(base_amount - (base_amount * (self.tax_level / 1000000))))
 
         o = c.total_supply(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
@@ -86,9 +87,9 @@ class TestRedistributionSingle(TestDemurrageSingle):
 
         o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
-        balance = c.parse_balance_of(r)
-        base_amount = new_supply * (self.tax_level / 1000000)
-        self.assertEqual(balance, base_amount - (base_amount * (self.tax_level / 1000000)))
+        balance = c.parse_balance(r)
+        expected_balance = new_supply - (new_supply * tax_modifier)
+        self.assert_within_lower(balance, expected_balance, 1)
 
 
 if __name__ == '__main__':

solidity/DemurrageTokenMultiCap.sol

@@ -1,616 +0,0 @@
-pragma solidity > 0.6.11;
-
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-contract DemurrageTokenMultiCap {
-
-	// Redistribution bit field, with associated shifts and masks
-	// (Uses sub-byte boundaries)
-	bytes32[] public redistributions; // uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	uint8 constant shiftRedistributionPeriod 	= 0;
-	uint256 constant maskRedistributionPeriod 	= 0x00000000000000000000000000000000000000000000000000000000ffffffff; // (1 << 32) - 1
-	uint8 constant shiftRedistributionValue 	= 32;
-	uint256 constant maskRedistributionValue	= 0x00000000000000000000000000000000000000ffffffffffffffffff00000000; // ((1 << 72) - 1) << 32
-	uint8 constant shiftRedistributionParticipants	= 104;
-	uint256 constant maskRedistributionParticipants	= 0x00000000000000000000000000000fffffffff00000000000000000000000000; // ((1 << 36) - 1) << 104
-	uint8 constant shiftRedistributionDemurrage	= 140;
-	uint256 constant maskRedistributionDemurrage	= 0x000000000000000000000000fffff00000000000000000000000000000000000; // ((1 << 20) - 1) << 140
-	uint8 constant shiftRedistributionIsFractional	= 255;
-	uint256 constant maskRedistributionIsFractional	= 0x8000000000000000000000000000000000000000000000000000000000000000; // 1 << 255
-
-	// Account bit field, with associated shifts and masks
-	// Mirrors structure of redistributions for consistency
-	mapping (address => bytes32) account; // uint152(unused) | uint32(period) | uint72(value)
-	uint8 constant shiftAccountValue		= 0;
-	uint256 constant maskAccountValue 		= 0x0000000000000000000000000000000000000000000000ffffffffffffffffff; // (1 << 72) - 1
-	uint8 constant shiftAccountPeriod		= 72;
-	uint256 constant maskAccountPeriod 		= 0x00000000000000000000000000000000000000ffffffff000000000000000000; // ((1 << 32) - 1) << 72
-
-	// Cached demurrage amount, ppm with 38 digit resolution
-	uint128 public demurrageAmount;
-
-	// Cached demurrage period; the period for which demurrageAmount was calculated
-	uint128 public demurragePeriod;
-
-	// Implements EIP172
-	address public owner;
-
-	address newOwner;
-
-	// Implements ERC20
-	string public name;
-
-	// Implements ERC20
-	string public symbol;
-
-	// Implements ERC20
-	uint256 public decimals;
-
-	// Implements ERC20
-	uint256 public totalSupply;
-
-	// Maximum amount of tokens that can be minted
-	uint256 public supplyCap;
-
-	// Minimum amount of (demurraged) tokens an account must spend to participate in redistribution for a particular period
-	uint256 public minimumParticipantSpend;
-
-	// 128 bit resolution of the demurrage divisor
-	// (this constant x 1000000 is contained within 128 bits)
-	uint256 constant ppmDivider = 100000000000000000000000000000000;
-
-	// Timestamp of start of periods (time which contract constructor was called)
-	uint256 public immutable periodStart;
-
-	// Duration of a single redistribution period in seconds
-	uint256 public immutable periodDuration;
-
-	// Demurrage in ppm per minute
-	uint256 public immutable taxLevel;
-
-	// Addresses allowed to mint new tokens
-	mapping (address => bool) minter;
-
-	// Storage for ERC20 approve/transferFrom methods
-	mapping (address => mapping (address => uint256 ) ) allowance; // holder -> spender -> amount (amount is subject to demurrage)
-
-	// Address to send unallocated redistribution tokens
-	address sinkAddress; 
-
-	// Implements ERC20
-	event Transfer(address indexed _from, address indexed _to, uint256 _value);
-
-	// Implements ERC20
-	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
-
-	// New tokens minted
-	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value);
-
-	// New demurrage cache milestone calculated
-	event Decayed(uint256 indexed _period, uint256 indexed _periodCount, uint256 indexed _oldAmount, uint256 _newAmount);
-
-	// When a new period threshold has been crossed
-	event Period(uint256 _period);
-
-	// Redistribution applied on a single eligible account
-	event Redistribution(address indexed _account, uint256 indexed _period, uint256 _value);
-
-	// Temporary event used in development, will be removed on prod
-	event Debug(bytes32 _foo);
-
-	// EIP173
-	event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); // EIP173
-
-	constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _taxLevelMinute, uint256 _periodMinutes, address _defaultSinkAddress, uint256 _supplyCap) public {
-		// ACL setup
-		owner = msg.sender;
-		minter[owner] = true;
-
-		// ERC20 setup
-		name = _name;
-		symbol = _symbol;
-		decimals = _decimals;
-
-		// Demurrage setup
-		periodStart = block.timestamp;
-		periodDuration = _periodMinutes * 60;
-		demurrageAmount = uint128(ppmDivider * 1000000); // Represents 38 decimal places
-		demurragePeriod = 1;
-		taxLevel = _taxLevelMinute; // Represents 38 decimal places
-		bytes32 initialRedistribution = toRedistribution(0, 1000000, 0, 1);
-		redistributions.push(initialRedistribution);
-
-		// Misc settings
-		supplyCap = _supplyCap;
-		sinkAddress = _defaultSinkAddress;
-		minimumParticipantSpend = 10 ** uint256(_decimals);
-	}
-
-	// Given address will be allowed to call the mintTo() function
-	function addMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner);
-		minter[_minter] = true;
-		return true;
-	}
-
-	// Given address will no longer be allowed to call the mintTo() function
-	function removeMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner || _minter == msg.sender);
-		minter[_minter] = false;
-		return true;
-	}
-
-	/// Implements ERC20
-	function balanceOf(address _account) public view returns (uint256) {
-		uint256 baseBalance;
-		uint256 currentDemurragedAmount;
-		uint256 periodCount;
-
-		baseBalance = baseBalanceOf(_account);
-
-		periodCount = actualPeriod() - demurragePeriod; 
-
-		currentDemurragedAmount = uint128(decayBy(demurrageAmount, periodCount));
-
-		return (baseBalance * currentDemurragedAmount) / (ppmDivider * 1000000);
-	}
-
-	/// Balance unmodified by demurrage
-	function baseBalanceOf(address _account) public view returns (uint256) {
-		return uint256(account[_account]) & maskAccountValue;
-	}
-
-	/// Increases base balance for a single account
-	function increaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-		uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-	
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);
-		newBalance = oldBalance + _delta;
-		require(uint160(newBalance) > uint160(oldBalance), 'ERR_WOULDWRAP'); // revert if increase would result in a wrapped value
-		workAccount &= (~maskAccountValue); 
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	/// Decreases base balance for a single account
-	function decreaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-	       	uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);	
-		require(oldBalance >= _delta, 'ERR_OVERSPEND'); // overspend guard
-		newBalance = oldBalance - _delta;
-		workAccount &= (~maskAccountValue);
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	// Creates new tokens out of thin air, and allocates them to the given address
-	// Triggers tax
-	function mintTo(address _beneficiary, uint256 _amount) external returns (bool) {
-		uint256 baseAmount;
-
-		require(minter[msg.sender]);
-		require(_amount + totalSupply <= supplyCap);
-
-		changePeriod();
-		baseAmount = _amount;
-		totalSupply += _amount;
-		increaseBaseBalance(_beneficiary, baseAmount);
-		emit Mint(msg.sender, _beneficiary, _amount);
-		saveRedistributionSupply();
-		return true;
-	}
-
-	// Deserializes the redistribution word
-	// uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) private pure returns(bytes32) {
-		bytes32 redistribution;
-
-		redistribution |= bytes32((_demurrageModifierPpm << shiftRedistributionDemurrage) & maskRedistributionDemurrage);
-		redistribution |= bytes32((_participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-		redistribution |= bytes32((_value << shiftRedistributionValue) & maskRedistributionValue); 
-		redistribution |= bytes32(_period & maskRedistributionPeriod);
-		return redistribution;
-	}
-
-	// Serializes the demurrage period part of the redistribution word
-	function toRedistributionPeriod(bytes32 redistribution) public pure returns (uint256) {
-		return uint256(redistribution) & maskRedistributionPeriod;
-	}
-
-	// Serializes the supply part of the redistribution word
-	function toRedistributionSupply(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionValue) >> shiftRedistributionValue;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionParticipants(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionParticipants) >> shiftRedistributionParticipants;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionDemurrageModifier(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionDemurrage) >> shiftRedistributionDemurrage;
-	}
-
-	// Client accessor to the redistributions array length
-	function redistributionCount() public view returns (uint256) {
-		return redistributions.length;
-	}
-
-	// Add number of participants for the current redistribution period by one
-	function incrementRedistributionParticipants() private returns (bool) {
-		bytes32 currentRedistribution;
-		uint256 tmpRedistribution;
-		uint256 participants;
-
-		currentRedistribution = redistributions[redistributions.length-1];
-		participants = toRedistributionParticipants(currentRedistribution) + 1;
-		tmpRedistribution = uint256(currentRedistribution);
-		tmpRedistribution &= (~maskRedistributionParticipants);
-		tmpRedistribution |= ((participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-
-		redistributions[redistributions.length-1] = bytes32(tmpRedistribution);
-
-		return true;
-	}
-
-	// Save the current total supply amount to the current redistribution period
-	function saveRedistributionSupply() private returns (bool) {
-		uint256 currentRedistribution;
-
-		currentRedistribution = uint256(redistributions[redistributions.length-1]);
-		currentRedistribution &= (~maskRedistributionValue);
-		currentRedistribution |= (totalSupply << shiftRedistributionValue);
-
-		redistributions[redistributions.length-1] = bytes32(currentRedistribution);
-		return true;
-	}
-
-	// Get the demurrage period of the current block number
-	function actualPeriod() public view returns (uint128) {
-		return uint128((block.timestamp - periodStart) / periodDuration + 1);
-	}
-
-	// Add an entered demurrage period to the redistribution array
-	function checkPeriod() private view returns (bytes32) {
-		bytes32 lastRedistribution;
-		uint256 currentPeriod;
-
-		lastRedistribution =  redistributions[redistributions.length-1];
-		currentPeriod = this.actualPeriod();
-		if (currentPeriod <= toRedistributionPeriod(lastRedistribution)) {
-			return bytes32(0x00);
-		}
-		return lastRedistribution;
-	}
-
-	// Deserialize the pemurrage period for the given account is participating in
-	function accountPeriod(address _account) public view returns (uint256) {
-		return (uint256(account[_account]) & maskAccountPeriod) >> shiftAccountPeriod;
-	}
-
-	// Save the given demurrage period as the currently participation period for the given address
-	function registerAccountPeriod(address _account, uint256 _period) private returns (bool) {
-		account[_account] &= bytes32(~maskAccountPeriod);
-		account[_account] |= bytes32((_period << shiftAccountPeriod) & maskAccountPeriod);
-		incrementRedistributionParticipants();
-		return true;
-	}
-
-	// Determine whether the unit number is rounded down, rounded up or evenly divides.
-	// Returns 0 if evenly distributed, or the remainder as a positive number
-	// A _numParts value 0 will be interpreted as the value 1
-	function remainder(uint256 _numParts, uint256 _sumWhole) public pure returns (uint256) {
-		uint256 unit;
-		uint256 truncatedResult;
-
-		if (_numParts == 0) { // no division by zero please
-			revert('ERR_NUMPARTS_ZERO');
-		}
-		require(_numParts < _sumWhole); // At least you are never LESS than the sum of your parts. Think about that.
-
-		unit = _sumWhole / _numParts;
-		truncatedResult = unit * _numParts;
-		return _sumWhole - truncatedResult;
-	}
-
-	// Called in the edge case where participant number is 0. It will override the participant count to 1.
-	// Returns the remainder sent to the sink address
-	function applyDefaultRedistribution(bytes32 _redistribution) private returns (uint256) {
-		uint256 redistributionSupply;
-		uint256 redistributionPeriod;
-		uint256 unit;
-		uint256 truncatedResult;
-
-		redistributionSupply = toRedistributionSupply(_redistribution);
-
-		unit = (redistributionSupply * taxLevel) / 1000000;
-		truncatedResult = (unit * 1000000) / taxLevel;
-
-		if (truncatedResult < redistributionSupply) {
-			redistributionPeriod = toRedistributionPeriod(_redistribution); // since we reuse period here, can possibly be optimized by passing period instead
-			redistributions[redistributionPeriod-1] &= bytes32(~maskRedistributionParticipants); // just to be safe, zero out all participant count data, in this case there will be only one
-			redistributions[redistributionPeriod-1] |= bytes32(maskRedistributionIsFractional | (1 << shiftRedistributionParticipants));
-		}
-
-		increaseBaseBalance(sinkAddress, unit / ppmDivider);
-		return unit;
-	}
-
-	// sets the remainder bit for the given period and books the remainder to the sink address balance
-	// returns false if no change was made
-	function applyRemainderOnPeriod(uint256 _remainder, uint256 _period) private returns (bool) {
-		uint256 periodSupply;
-
-		if (_remainder == 0) {
-			return false;
-		}
-
-		// TODO: is this needed?
-		redistributions[_period-1] |= bytes32(maskRedistributionIsFractional);
-
-		periodSupply = toRedistributionSupply(redistributions[_period-1]);
-		increaseBaseBalance(sinkAddress, periodSupply - _remainder);
-		return true;
-	}
-
-
-	// Calculate and cache the demurrage value corresponding to the (period of the) time of the method call
-	function applyDemurrage() public returns (bool) {
-		uint128 epochPeriodCount;
-		uint128 periodCount;
-		uint256 lastDemurrageAmount;
-		uint256 newDemurrageAmount;
-
-		epochPeriodCount = actualPeriod();
-		periodCount = epochPeriodCount - demurragePeriod;
-		if (periodCount == 0) {
-			return false;
-		}
-		lastDemurrageAmount = demurrageAmount;
-		demurrageAmount = uint128(decayBy(lastDemurrageAmount, periodCount));
-		demurragePeriod = epochPeriodCount; 
-		emit Decayed(epochPeriodCount, periodCount, lastDemurrageAmount, demurrageAmount);
-		return true;
-	}
-
-	// Return timestamp of start of period threshold
-	function getPeriodTimeDelta(uint256 _periodCount) public view returns (uint256) {
-		return periodStart + (_periodCount * periodDuration);
-	}
-
-	// Amount of demurrage cycles inbetween the current timestamp and the given target time
-	function demurrageCycles(uint256 _target) public view returns (uint256) {
-		return (block.timestamp - _target) / 60;
-	}
-
-	// Recalculate the demurrage modifier for the new period
-	// After this, all REPORTED balances will have been reduced by the corresponding ratio (but the effecive totalsupply stays the same)
-	function changePeriod() public returns (bool) {
-		bytes32 currentRedistribution;
-		bytes32 nextRedistribution;
-		uint256 currentPeriod;
-		uint256 currentParticipants;
-		uint256 currentRemainder;
-		uint256 currentDemurrageAmount;
-		uint256 nextRedistributionDemurrage;
-		uint256 demurrageCounts;
-		uint256 periodTimestamp;
-		uint256 nextPeriod;
-
-		currentRedistribution = checkPeriod();
-		if (currentRedistribution == bytes32(0x00)) {
-			return false;
-		}
-
-		currentPeriod = toRedistributionPeriod(currentRedistribution);
-		nextPeriod = currentPeriod + 1;
-		periodTimestamp = getPeriodTimeDelta(currentPeriod);
-
-		applyDemurrage();
-		currentDemurrageAmount = demurrageAmount; 
-
-		demurrageCounts = demurrageCycles(periodTimestamp);
-		if (demurrageCounts > 0) {
-			nextRedistributionDemurrage = growBy(currentDemurrageAmount, demurrageCounts) / ppmDivider;
-		} else {
-			nextRedistributionDemurrage = currentDemurrageAmount / ppmDivider;
-		}
-		
-		nextRedistribution = toRedistribution(0, nextRedistributionDemurrage, totalSupply, nextPeriod);
-		redistributions.push(nextRedistribution);
-
-		currentParticipants = toRedistributionParticipants(currentRedistribution);
-		if (currentParticipants == 0) {
-			currentRemainder = applyDefaultRedistribution(currentRedistribution);
-		} else {
-			currentRemainder = remainder(currentParticipants, totalSupply); // we can use totalSupply directly because it will always be the same as the recorded supply on the current redistribution
-			applyRemainderOnPeriod(currentRemainder, currentPeriod);
-		}
-		emit Period(nextPeriod);
-		return true;
-	}
-
-	// Reverse a value reduced by demurrage by the given period to its original value
-	function growBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor + ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// Calculate a value reduced by demurrage by the given period
-	// TODO: higher precision if possible
-	function decayBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor - ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// If the given account is participating in a period and that period has been crossed
-	// THEN increase the base value of the account with its share of the value reduction of the period
-	function applyRedistributionOnAccount(address _account) public returns (bool) {
-		bytes32 periodRedistribution;
-		uint256 supply;
-		uint256 participants;
-		uint256 baseValue;
-		uint256 value;
-		uint256 period;
-		uint256 demurrage;
-	       
-		period = accountPeriod(_account);
-		if (period == 0 || period >= actualPeriod()) {
-			return false;
-		}
-		periodRedistribution = redistributions[period-1];
-		participants = toRedistributionParticipants(periodRedistribution);
-		if (participants == 0) {
-			return false;
-		}
-
-		supply = toRedistributionSupply(periodRedistribution);
-		demurrage = toRedistributionDemurrageModifier(periodRedistribution);
-		baseValue = ((supply / participants) * (taxLevel / 1000000)) / ppmDivider;
-		value = (baseValue * demurrage) / 1000000;
-
-		// zero out period for the account
-		account[_account] &= bytes32(~maskAccountPeriod); 
-		increaseBaseBalance(_account, value);
-
-		emit Redistribution(_account, period, value);
-		return true;
-	}
-
-	// Inflates the given amount according to the current demurrage modifier
-	function toBaseAmount(uint256 _value) public view returns (uint256) {
-		//return (_value * ppmDivider * 1000000) / toDemurrageAmount(demurrageModifier);
-		return (_value * ppmDivider * 1000000) / demurrageAmount;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function approve(address _spender, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		allowance[msg.sender][_spender] += baseValue;
-		emit Approval(msg.sender, _spender, _value);
-		return true;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transfer(address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		result = transferBase(msg.sender, _to, baseValue);
-		emit Transfer(msg.sender, _to, _value);
-		return result;
-	}
-
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		require(allowance[_from][msg.sender] >= baseValue);
-
-		result = transferBase(_from, _to, baseValue);
-		emit Transfer(_from, _to, _value);
-		return result;
-	}
-
-	// ERC20 transfer backend for transfer, transferFrom
-	function transferBase(address _from, address _to, uint256 _value) private returns (bool) {
-		uint256 period;
-
-		decreaseBaseBalance(_from, _value);
-		increaseBaseBalance(_to, _value);
-
-		period = actualPeriod();
-		if (_value >= minimumParticipantSpend && accountPeriod(_from) != period && _from != _to) {
-			registerAccountPeriod(_from, period);
-		}
-		return true;
-	}
-
-	// Implements EIP173
-	function transferOwnership(address _newOwner) public returns (bool) {
-		require(msg.sender == owner);
-		newOwner = _newOwner;
-	}
-
-	// Implements OwnedAccepter
-	function acceptOwnership() public returns (bool) {
-		address oldOwner;
-
-		require(msg.sender == newOwner);
-		oldOwner = owner; 
-		owner = newOwner;
-		newOwner = address(0);
-		emit OwnershipTransferred(oldOwner, owner);
-	}
-
-	// Implements EIP165
-	function supportsInterface(bytes4 _sum) public pure returns (bool) {
-		if (_sum == 0xc6bb4b70) { // ERC20
-			return true;
-		}
-		if (_sum == 0x449a52f8) { // Minter
-			return true;
-		}
-		if (_sum == 0x01ffc9a7) { // EIP165
-			return true;
-		}
-		if (_sum == 0x9493f8b2) { // EIP173
-			return true;
-		}
-		if (_sum == 0x37a47be4) { // OwnedAccepter
-			return true;
-		}
-		return false;
-	}
-}

solidity/DemurrageTokenMultiNocap.sol

@@ -1,611 +0,0 @@
-pragma solidity > 0.6.11;
-
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-contract DemurrageTokenMultiNocap {
-
-	// Redistribution bit field, with associated shifts and masks
-	// (Uses sub-byte boundaries)
-	bytes32[] public redistributions; // uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	uint8 constant shiftRedistributionPeriod 	= 0;
-	uint256 constant maskRedistributionPeriod 	= 0x00000000000000000000000000000000000000000000000000000000ffffffff; // (1 << 32) - 1
-	uint8 constant shiftRedistributionValue 	= 32;
-	uint256 constant maskRedistributionValue	= 0x00000000000000000000000000000000000000ffffffffffffffffff00000000; // ((1 << 72) - 1) << 32
-	uint8 constant shiftRedistributionParticipants	= 104;
-	uint256 constant maskRedistributionParticipants	= 0x00000000000000000000000000000fffffffff00000000000000000000000000; // ((1 << 36) - 1) << 104
-	uint8 constant shiftRedistributionDemurrage	= 140;
-	uint256 constant maskRedistributionDemurrage	= 0x000000000000000000000000fffff00000000000000000000000000000000000; // ((1 << 20) - 1) << 140
-	uint8 constant shiftRedistributionIsFractional	= 255;
-	uint256 constant maskRedistributionIsFractional	= 0x8000000000000000000000000000000000000000000000000000000000000000; // 1 << 255
-
-	// Account bit field, with associated shifts and masks
-	// Mirrors structure of redistributions for consistency
-	mapping (address => bytes32) account; // uint152(unused) | uint32(period) | uint72(value)
-	uint8 constant shiftAccountValue		= 0;
-	uint256 constant maskAccountValue 		= 0x0000000000000000000000000000000000000000000000ffffffffffffffffff; // (1 << 72) - 1
-	uint8 constant shiftAccountPeriod		= 72;
-	uint256 constant maskAccountPeriod 		= 0x00000000000000000000000000000000000000ffffffff000000000000000000; // ((1 << 32) - 1) << 72
-
-	// Cached demurrage amount, ppm with 38 digit resolution
-	uint128 public demurrageAmount;
-
-	// Cached demurrage period; the period for which demurrageAmount was calculated
-	uint128 public demurragePeriod;
-
-	// Implements EIP172
-	address public owner;
-
-	address newOwner;
-
-	// Implements ERC20
-	string public name;
-
-	// Implements ERC20
-	string public symbol;
-
-	// Implements ERC20
-	uint256 public decimals;
-
-	// Implements ERC20
-	uint256 public totalSupply;
-
-	// Minimum amount of (demurraged) tokens an account must spend to participate in redistribution for a particular period
-	uint256 public minimumParticipantSpend;
-
-	// 128 bit resolution of the demurrage divisor
-	// (this constant x 1000000 is contained within 128 bits)
-	uint256 constant ppmDivider = 100000000000000000000000000000000;
-
-	// Timestamp of start of periods (time which contract constructor was called)
-	uint256 public immutable periodStart;
-
-	// Duration of a single redistribution period in seconds
-	uint256 public immutable periodDuration;
-
-	// Demurrage in ppm per minute
-	uint256 public immutable taxLevel;
-
-	// Addresses allowed to mint new tokens
-	mapping (address => bool) minter;
-
-	// Storage for ERC20 approve/transferFrom methods
-	mapping (address => mapping (address => uint256 ) ) allowance; // holder -> spender -> amount (amount is subject to demurrage)
-
-	// Address to send unallocated redistribution tokens
-	address sinkAddress; 
-
-	// Implements ERC20
-	event Transfer(address indexed _from, address indexed _to, uint256 _value);
-
-	// Implements ERC20
-	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
-
-	// New tokens minted
-	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value);
-
-	// New demurrage cache milestone calculated
-	event Decayed(uint256 indexed _period, uint256 indexed _periodCount, uint256 indexed _oldAmount, uint256 _newAmount);
-
-	// When a new period threshold has been crossed
-	event Period(uint256 _period);
-
-	// Redistribution applied on a single eligible account
-	event Redistribution(address indexed _account, uint256 indexed _period, uint256 _value);
-
-	// Temporary event used in development, will be removed on prod
-	event Debug(bytes32 _foo);
-
-	// EIP173
-	event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); // EIP173
-
-	constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _taxLevelMinute, uint256 _periodMinutes, address _defaultSinkAddress) public {
-		// ACL setup
-		owner = msg.sender;
-		minter[owner] = true;
-
-		// ERC20 setup
-		name = _name;
-		symbol = _symbol;
-		decimals = _decimals;
-
-		// Demurrage setup
-		periodStart = block.timestamp;
-		periodDuration = _periodMinutes * 60;
-		demurrageAmount = uint128(ppmDivider * 1000000); // Represents 38 decimal places
-		demurragePeriod = 1;
-		taxLevel = _taxLevelMinute; // Represents 38 decimal places
-		bytes32 initialRedistribution = toRedistribution(0, 1000000, 0, 1);
-		redistributions.push(initialRedistribution);
-
-		// Misc settings
-		sinkAddress = _defaultSinkAddress;
-		minimumParticipantSpend = 10 ** uint256(_decimals);
-	}
-
-	// Given address will be allowed to call the mintTo() function
-	function addMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner);
-		minter[_minter] = true;
-		return true;
-	}
-
-	// Given address will no longer be allowed to call the mintTo() function
-	function removeMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner || _minter == msg.sender);
-		minter[_minter] = false;
-		return true;
-	}
-
-	/// Implements ERC20
-	function balanceOf(address _account) public view returns (uint256) {
-		uint256 baseBalance;
-		uint256 currentDemurragedAmount;
-		uint256 periodCount;
-
-		baseBalance = baseBalanceOf(_account);
-
-		periodCount = actualPeriod() - demurragePeriod; 
-
-		currentDemurragedAmount = uint128(decayBy(demurrageAmount, periodCount));
-
-		return (baseBalance * currentDemurragedAmount) / (ppmDivider * 1000000);
-	}
-
-	/// Balance unmodified by demurrage
-	function baseBalanceOf(address _account) public view returns (uint256) {
-		return uint256(account[_account]) & maskAccountValue;
-	}
-
-	/// Increases base balance for a single account
-	function increaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-		uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-	
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);
-		newBalance = oldBalance + _delta;
-		require(uint160(newBalance) > uint160(oldBalance), 'ERR_WOULDWRAP'); // revert if increase would result in a wrapped value
-		workAccount &= (~maskAccountValue); 
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	/// Decreases base balance for a single account
-	function decreaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-	       	uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);	
-		require(oldBalance >= _delta, 'ERR_OVERSPEND'); // overspend guard
-		newBalance = oldBalance - _delta;
-		workAccount &= (~maskAccountValue);
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	// Creates new tokens out of thin air, and allocates them to the given address
-	// Triggers tax
-	function mintTo(address _beneficiary, uint256 _amount) external returns (bool) {
-		uint256 baseAmount;
-
-		require(minter[msg.sender]);
-
-		changePeriod();
-		baseAmount = _amount;
-		totalSupply += _amount;
-		increaseBaseBalance(_beneficiary, baseAmount);
-		emit Mint(msg.sender, _beneficiary, _amount);
-		saveRedistributionSupply();
-		return true;
-	}
-
-	// Deserializes the redistribution word
-	// uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) private pure returns(bytes32) {
-		bytes32 redistribution;
-
-		redistribution |= bytes32((_demurrageModifierPpm << shiftRedistributionDemurrage) & maskRedistributionDemurrage);
-		redistribution |= bytes32((_participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-		redistribution |= bytes32((_value << shiftRedistributionValue) & maskRedistributionValue); 
-		redistribution |= bytes32(_period & maskRedistributionPeriod);
-		return redistribution;
-	}
-
-	// Serializes the demurrage period part of the redistribution word
-	function toRedistributionPeriod(bytes32 redistribution) public pure returns (uint256) {
-		return uint256(redistribution) & maskRedistributionPeriod;
-	}
-
-	// Serializes the supply part of the redistribution word
-	function toRedistributionSupply(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionValue) >> shiftRedistributionValue;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionParticipants(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionParticipants) >> shiftRedistributionParticipants;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionDemurrageModifier(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionDemurrage) >> shiftRedistributionDemurrage;
-	}
-
-	// Client accessor to the redistributions array length
-	function redistributionCount() public view returns (uint256) {
-		return redistributions.length;
-	}
-
-	// Add number of participants for the current redistribution period by one
-	function incrementRedistributionParticipants() private returns (bool) {
-		bytes32 currentRedistribution;
-		uint256 tmpRedistribution;
-		uint256 participants;
-
-		currentRedistribution = redistributions[redistributions.length-1];
-		participants = toRedistributionParticipants(currentRedistribution) + 1;
-		tmpRedistribution = uint256(currentRedistribution);
-		tmpRedistribution &= (~maskRedistributionParticipants);
-		tmpRedistribution |= ((participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-
-		redistributions[redistributions.length-1] = bytes32(tmpRedistribution);
-
-		return true;
-	}
-
-	// Save the current total supply amount to the current redistribution period
-	function saveRedistributionSupply() private returns (bool) {
-		uint256 currentRedistribution;
-
-		currentRedistribution = uint256(redistributions[redistributions.length-1]);
-		currentRedistribution &= (~maskRedistributionValue);
-		currentRedistribution |= (totalSupply << shiftRedistributionValue);
-
-		redistributions[redistributions.length-1] = bytes32(currentRedistribution);
-		return true;
-	}
-
-	// Get the demurrage period of the current block number
-	function actualPeriod() public view returns (uint128) {
-		return uint128((block.timestamp - periodStart) / periodDuration + 1);
-	}
-
-	// Add an entered demurrage period to the redistribution array
-	function checkPeriod() private view returns (bytes32) {
-		bytes32 lastRedistribution;
-		uint256 currentPeriod;
-
-		lastRedistribution =  redistributions[redistributions.length-1];
-		currentPeriod = this.actualPeriod();
-		if (currentPeriod <= toRedistributionPeriod(lastRedistribution)) {
-			return bytes32(0x00);
-		}
-		return lastRedistribution;
-	}
-
-	// Deserialize the pemurrage period for the given account is participating in
-	function accountPeriod(address _account) public view returns (uint256) {
-		return (uint256(account[_account]) & maskAccountPeriod) >> shiftAccountPeriod;
-	}
-
-	// Save the given demurrage period as the currently participation period for the given address
-	function registerAccountPeriod(address _account, uint256 _period) private returns (bool) {
-		account[_account] &= bytes32(~maskAccountPeriod);
-		account[_account] |= bytes32((_period << shiftAccountPeriod) & maskAccountPeriod);
-		incrementRedistributionParticipants();
-		return true;
-	}
-
-	// Determine whether the unit number is rounded down, rounded up or evenly divides.
-	// Returns 0 if evenly distributed, or the remainder as a positive number
-	// A _numParts value 0 will be interpreted as the value 1
-	function remainder(uint256 _numParts, uint256 _sumWhole) public pure returns (uint256) {
-		uint256 unit;
-		uint256 truncatedResult;
-
-		if (_numParts == 0) { // no division by zero please
-			revert('ERR_NUMPARTS_ZERO');
-		}
-		require(_numParts < _sumWhole); // At least you are never LESS than the sum of your parts. Think about that.
-
-		unit = _sumWhole / _numParts;
-		truncatedResult = unit * _numParts;
-		return _sumWhole - truncatedResult;
-	}
-
-	// Called in the edge case where participant number is 0. It will override the participant count to 1.
-	// Returns the remainder sent to the sink address
-	function applyDefaultRedistribution(bytes32 _redistribution) private returns (uint256) {
-		uint256 redistributionSupply;
-		uint256 redistributionPeriod;
-		uint256 unit;
-		uint256 truncatedResult;
-
-		redistributionSupply = toRedistributionSupply(_redistribution);
-
-		unit = (redistributionSupply * taxLevel) / 1000000;
-		truncatedResult = (unit * 1000000) / taxLevel;
-
-		if (truncatedResult < redistributionSupply) {
-			redistributionPeriod = toRedistributionPeriod(_redistribution); // since we reuse period here, can possibly be optimized by passing period instead
-			redistributions[redistributionPeriod-1] &= bytes32(~maskRedistributionParticipants); // just to be safe, zero out all participant count data, in this case there will be only one
-			redistributions[redistributionPeriod-1] |= bytes32(maskRedistributionIsFractional | (1 << shiftRedistributionParticipants));
-		}
-
-		increaseBaseBalance(sinkAddress, unit / ppmDivider);
-		return unit;
-	}
-
-	// sets the remainder bit for the given period and books the remainder to the sink address balance
-	// returns false if no change was made
-	function applyRemainderOnPeriod(uint256 _remainder, uint256 _period) private returns (bool) {
-		uint256 periodSupply;
-
-		if (_remainder == 0) {
-			return false;
-		}
-
-		// TODO: is this needed?
-		redistributions[_period-1] |= bytes32(maskRedistributionIsFractional);
-
-		periodSupply = toRedistributionSupply(redistributions[_period-1]);
-		increaseBaseBalance(sinkAddress, periodSupply - _remainder);
-		return true;
-	}
-
-
-	// Calculate and cache the demurrage value corresponding to the (period of the) time of the method call
-	function applyDemurrage() public returns (bool) {
-		uint128 epochPeriodCount;
-		uint128 periodCount;
-		uint256 lastDemurrageAmount;
-		uint256 newDemurrageAmount;
-
-		epochPeriodCount = actualPeriod();
-		periodCount = epochPeriodCount - demurragePeriod;
-		if (periodCount == 0) {
-			return false;
-		}
-		lastDemurrageAmount = demurrageAmount;
-		demurrageAmount = uint128(decayBy(lastDemurrageAmount, periodCount));
-		demurragePeriod = epochPeriodCount; 
-		emit Decayed(epochPeriodCount, periodCount, lastDemurrageAmount, demurrageAmount);
-		return true;
-	}
-
-	// Return timestamp of start of period threshold
-	function getPeriodTimeDelta(uint256 _periodCount) public view returns (uint256) {
-		return periodStart + (_periodCount * periodDuration);
-	}
-
-	// Amount of demurrage cycles inbetween the current timestamp and the given target time
-	function demurrageCycles(uint256 _target) public view returns (uint256) {
-		return (block.timestamp - _target) / 60;
-	}
-
-	// Recalculate the demurrage modifier for the new period
-	// After this, all REPORTED balances will have been reduced by the corresponding ratio (but the effecive totalsupply stays the same)
-	function changePeriod() public returns (bool) {
-		bytes32 currentRedistribution;
-		bytes32 nextRedistribution;
-		uint256 currentPeriod;
-		uint256 currentParticipants;
-		uint256 currentRemainder;
-		uint256 currentDemurrageAmount;
-		uint256 nextRedistributionDemurrage;
-		uint256 demurrageCounts;
-		uint256 periodTimestamp;
-		uint256 nextPeriod;
-
-		currentRedistribution = checkPeriod();
-		if (currentRedistribution == bytes32(0x00)) {
-			return false;
-		}
-
-		currentPeriod = toRedistributionPeriod(currentRedistribution);
-		nextPeriod = currentPeriod + 1;
-		periodTimestamp = getPeriodTimeDelta(currentPeriod);
-
-		applyDemurrage();
-		currentDemurrageAmount = demurrageAmount; 
-
-		demurrageCounts = demurrageCycles(periodTimestamp);
-		if (demurrageCounts > 0) {
-			nextRedistributionDemurrage = growBy(currentDemurrageAmount, demurrageCounts) / ppmDivider;
-		} else {
-			nextRedistributionDemurrage = currentDemurrageAmount / ppmDivider;
-		}
-		
-		nextRedistribution = toRedistribution(0, nextRedistributionDemurrage, totalSupply, nextPeriod);
-		redistributions.push(nextRedistribution);
-
-		currentParticipants = toRedistributionParticipants(currentRedistribution);
-		if (currentParticipants == 0) {
-			currentRemainder = applyDefaultRedistribution(currentRedistribution);
-		} else {
-			currentRemainder = remainder(currentParticipants, totalSupply); // we can use totalSupply directly because it will always be the same as the recorded supply on the current redistribution
-			applyRemainderOnPeriod(currentRemainder, currentPeriod);
-		}
-		emit Period(nextPeriod);
-		return true;
-	}
-
-	// Reverse a value reduced by demurrage by the given period to its original value
-	function growBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor + ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// Calculate a value reduced by demurrage by the given period
-	// TODO: higher precision if possible
-	function decayBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor - ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// If the given account is participating in a period and that period has been crossed
-	// THEN increase the base value of the account with its share of the value reduction of the period
-	function applyRedistributionOnAccount(address _account) public returns (bool) {
-		bytes32 periodRedistribution;
-		uint256 supply;
-		uint256 participants;
-		uint256 baseValue;
-		uint256 value;
-		uint256 period;
-		uint256 demurrage;
-	       
-		period = accountPeriod(_account);
-		if (period == 0 || period >= actualPeriod()) {
-			return false;
-		}
-		periodRedistribution = redistributions[period-1];
-		participants = toRedistributionParticipants(periodRedistribution);
-		if (participants == 0) {
-			return false;
-		}
-
-		supply = toRedistributionSupply(periodRedistribution);
-		demurrage = toRedistributionDemurrageModifier(periodRedistribution);
-		baseValue = ((supply / participants) * (taxLevel / 1000000)) / ppmDivider;
-		value = (baseValue * demurrage) / 1000000;
-
-		// zero out period for the account
-		account[_account] &= bytes32(~maskAccountPeriod); 
-		increaseBaseBalance(_account, value);
-
-		emit Redistribution(_account, period, value);
-		return true;
-	}
-
-	// Inflates the given amount according to the current demurrage modifier
-	function toBaseAmount(uint256 _value) public view returns (uint256) {
-		//return (_value * ppmDivider * 1000000) / toDemurrageAmount(demurrageModifier);
-		return (_value * ppmDivider * 1000000) / demurrageAmount;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function approve(address _spender, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		allowance[msg.sender][_spender] += baseValue;
-		emit Approval(msg.sender, _spender, _value);
-		return true;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transfer(address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		result = transferBase(msg.sender, _to, baseValue);
-		emit Transfer(msg.sender, _to, _value);
-		return result;
-	}
-
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		require(allowance[_from][msg.sender] >= baseValue);
-
-		result = transferBase(_from, _to, baseValue);
-		emit Transfer(_from, _to, _value);
-		return result;
-	}
-
-	// ERC20 transfer backend for transfer, transferFrom
-	function transferBase(address _from, address _to, uint256 _value) private returns (bool) {
-		uint256 period;
-
-		decreaseBaseBalance(_from, _value);
-		increaseBaseBalance(_to, _value);
-
-		period = actualPeriod();
-		if (_value >= minimumParticipantSpend && accountPeriod(_from) != period && _from != _to) {
-			registerAccountPeriod(_from, period);
-		}
-		return true;
-	}
-
-	// Implements EIP173
-	function transferOwnership(address _newOwner) public returns (bool) {
-		require(msg.sender == owner);
-		newOwner = _newOwner;
-	}
-
-	// Implements OwnedAccepter
-	function acceptOwnership() public returns (bool) {
-		address oldOwner;
-
-		require(msg.sender == newOwner);
-		oldOwner = owner; 
-		owner = newOwner;
-		newOwner = address(0);
-		emit OwnershipTransferred(oldOwner, owner);
-	}
-
-	// Implements EIP165
-	function supportsInterface(bytes4 _sum) public pure returns (bool) {
-		if (_sum == 0xc6bb4b70) { // ERC20
-			return true;
-		}
-		if (_sum == 0x449a52f8) { // Minter
-			return true;
-		}
-		if (_sum == 0x01ffc9a7) { // EIP165
-			return true;
-		}
-		if (_sum == 0x9493f8b2) { // EIP173
-			return true;
-		}
-		if (_sum == 0x37a47be4) { // OwnedAccepter
-			return true;
-		}
-		return false;
-	}
-}

solidity/DemurrageTokenSingleCap.sol

@@ -1,614 +0,0 @@
-pragma solidity > 0.6.11;
-
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-contract DemurrageTokenSingleNocap {
-
-	// Redistribution bit field, with associated shifts and masks
-	// (Uses sub-byte boundaries)
-	bytes32[] public redistributions; // uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	uint8 constant shiftRedistributionPeriod 	= 0;
-	uint256 constant maskRedistributionPeriod 	= 0x00000000000000000000000000000000000000000000000000000000ffffffff; // (1 << 32) - 1
-	uint8 constant shiftRedistributionValue 	= 32;
-	uint256 constant maskRedistributionValue	= 0x00000000000000000000000000000000000000ffffffffffffffffff00000000; // ((1 << 72) - 1) << 32
-	uint8 constant shiftRedistributionParticipants	= 104;
-	uint256 constant maskRedistributionParticipants	= 0x00000000000000000000000000000fffffffff00000000000000000000000000; // ((1 << 36) - 1) << 104
-	uint8 constant shiftRedistributionDemurrage	= 140;
-	uint256 constant maskRedistributionDemurrage	= 0x000000000000000000000000fffff00000000000000000000000000000000000; // ((1 << 20) - 1) << 140
-	uint8 constant shiftRedistributionIsFractional	= 255;
-	uint256 constant maskRedistributionIsFractional	= 0x8000000000000000000000000000000000000000000000000000000000000000; // 1 << 255
-
-	// Account bit field, with associated shifts and masks
-	// Mirrors structure of redistributions for consistency
-	mapping (address => bytes32) account; // uint152(unused) | uint32(period) | uint72(value)
-	uint8 constant shiftAccountValue		= 0;
-	uint256 constant maskAccountValue 		= 0x0000000000000000000000000000000000000000000000ffffffffffffffffff; // (1 << 72) - 1
-	uint8 constant shiftAccountPeriod		= 72;
-	uint256 constant maskAccountPeriod 		= 0x00000000000000000000000000000000000000ffffffff000000000000000000; // ((1 << 32) - 1) << 72
-	
-	// Cached demurrage amount, ppm with 38 digit resolution
-	uint128 public demurrageAmount;
-
-	// Cached demurrage period; the period for which demurrageAmount was calculated
-	uint128 public demurragePeriod;
-
-	// Implements EIP172
-	address public owner;
-
-	address newOwner;
-
-	// Implements ERC20
-	string public name;
-
-	// Implements ERC20
-	string public symbol;
-
-	// Implements ERC20
-	uint256 public decimals;
-
-	// Implements ERC20
-	uint256 public totalSupply;
-
-	// Maximum amount of tokens that can be minted
-	uint256 public supplyCap;
-
-	// Minimum amount of (demurraged) tokens an account must spend to participate in redistribution for a particular period
-	uint256 public minimumParticipantSpend;
-
-	// 128 bit resolution of the demurrage divisor
-	// (this constant x 1000000 is contained within 128 bits)
-	uint256 constant ppmDivider = 100000000000000000000000000000000;
-
-	// Timestamp of start of periods (time which contract constructor was called)
-	uint256 public immutable periodStart;
-
-	// Duration of a single redistribution period in seconds
-	uint256 public immutable periodDuration;
-
-	// Demurrage in ppm per minute
-	uint256 public immutable taxLevel;
-
-	// Addresses allowed to mint new tokens
-	mapping (address => bool) minter;
-
-	// Storage for ERC20 approve/transferFrom methods
-	mapping (address => mapping (address => uint256 ) ) allowance; // holder -> spender -> amount (amount is subject to demurrage)
-
-	// Address to send unallocated redistribution tokens
-	address sinkAddress; 
-
-	// Implements ERC20
-	event Transfer(address indexed _from, address indexed _to, uint256 _value);
-
-	// Implements ERC20
-	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
-
-	// New tokens minted
-	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value);
-
-	// New demurrage cache milestone calculated
-	event Decayed(uint256 indexed _period, uint256 indexed _periodCount, uint256 indexed _oldAmount, uint256 _newAmount);
-
-	// When a new period threshold has been crossed
-	event Period(uint256 _period);
-
-	// Redistribution applied on a single eligible account
-	event Redistribution(address indexed _account, uint256 indexed _period, uint256 _value);
-
-	// Temporary event used in development, will be removed on prod
-	event Debug(bytes32 _foo);
-
-	// EIP173
-	event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); // EIP173
-
-	constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _taxLevelMinute, uint256 _periodMinutes, address _defaultSinkAddress, uint256 _supplyCap) public {
-		// ACL setup
-		owner = msg.sender;
-		minter[owner] = true;
-
-		// ERC20 setup
-		name = _name;
-		symbol = _symbol;
-		decimals = _decimals;
-
-		// Demurrage setup
-		periodStart = block.timestamp;
-		periodDuration = _periodMinutes * 60;
-		demurrageAmount = uint128(ppmDivider * 1000000); // Represents 38 decimal places
-		demurragePeriod = 1;
-		taxLevel = _taxLevelMinute; // Represents 38 decimal places
-		bytes32 initialRedistribution = toRedistribution(0, 1000000, 0, 1);
-		redistributions.push(initialRedistribution);
-
-		// Misc settings
-		supplyCap = _supplyCap;
-		sinkAddress = _defaultSinkAddress;
-		minimumParticipantSpend = 10 ** uint256(_decimals);
-	}
-
-	// Given address will be allowed to call the mintTo() function
-	function addMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner);
-		minter[_minter] = true;
-		return true;
-	}
-
-	// Given address will no longer be allowed to call the mintTo() function
-	function removeMinter(address _minter) public returns (bool) {
-		require(msg.sender == owner || _minter == msg.sender);
-		minter[_minter] = false;
-		return true;
-	}
-
-	/// Implements ERC20
-	function balanceOf(address _account) public view returns (uint256) {
-		uint256 baseBalance;
-		uint256 currentDemurragedAmount;
-		uint256 periodCount;
-
-		baseBalance = baseBalanceOf(_account);
-
-		periodCount = actualPeriod() - demurragePeriod; 
-
-		currentDemurragedAmount = uint128(decayBy(demurrageAmount, periodCount));
-
-		return (baseBalance * currentDemurragedAmount) / (ppmDivider * 1000000);
-	}
-
-	/// Balance unmodified by demurrage
-	function baseBalanceOf(address _account) public view returns (uint256) {
-		return uint256(account[_account]) & maskAccountValue;
-	}
-
-	/// Increases base balance for a single account
-	function increaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-		uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-	
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);
-		newBalance = oldBalance + _delta;
-		require(uint160(newBalance) > uint160(oldBalance), 'ERR_WOULDWRAP'); // revert if increase would result in a wrapped value
-		workAccount &= (~maskAccountValue); 
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	/// Decreases base balance for a single account
-	function decreaseBaseBalance(address _account, uint256 _delta) private returns (bool) {
-		uint256 oldBalance;
-	       	uint256 newBalance;
-		uint256 workAccount;
-
-		workAccount = uint256(account[_account]);
-
-		if (_delta == 0) {
-			return false;
-		}
-
-		oldBalance = baseBalanceOf(_account);	
-		require(oldBalance >= _delta, 'ERR_OVERSPEND'); // overspend guard
-		newBalance = oldBalance - _delta;
-		workAccount &= (~maskAccountValue);
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
-		return true;
-	}
-
-	// Creates new tokens out of thin air, and allocates them to the given address
-	// Triggers tax
-	function mintTo(address _beneficiary, uint256 _amount) external returns (bool) {
-		uint256 baseAmount;
-
-		require(minter[msg.sender]);
-		require(_amount + totalSupply <= supplyCap);
-
-		changePeriod();
-		baseAmount = _amount;
-		totalSupply += _amount;
-		increaseBaseBalance(_beneficiary, baseAmount);
-		emit Mint(msg.sender, _beneficiary, _amount);
-		saveRedistributionSupply();
-		return true;
-	}
-
-	// Deserializes the redistribution word
-	// uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) private pure returns(bytes32) {
-		bytes32 redistribution;
-
-		redistribution |= bytes32((_demurrageModifierPpm << shiftRedistributionDemurrage) & maskRedistributionDemurrage);
-		redistribution |= bytes32((_participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-		redistribution |= bytes32((_value << shiftRedistributionValue) & maskRedistributionValue); 
-		redistribution |= bytes32(_period & maskRedistributionPeriod);
-		return redistribution;
-	}
-
-	// Serializes the demurrage period part of the redistribution word
-	function toRedistributionPeriod(bytes32 redistribution) public pure returns (uint256) {
-		return uint256(redistribution) & maskRedistributionPeriod;
-	}
-
-	// Serializes the supply part of the redistribution word
-	function toRedistributionSupply(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionValue) >> shiftRedistributionValue;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionParticipants(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionParticipants) >> shiftRedistributionParticipants;
-	}
-
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionDemurrageModifier(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionDemurrage) >> shiftRedistributionDemurrage;
-	}
-
-	// Client accessor to the redistributions array length
-	function redistributionCount() public view returns (uint256) {
-		return redistributions.length;
-	}
-
-	// Add number of participants for the current redistribution period by one
-	function incrementRedistributionParticipants() private returns (bool) {
-		bytes32 currentRedistribution;
-		uint256 tmpRedistribution;
-		uint256 participants;
-
-		currentRedistribution = redistributions[redistributions.length-1];
-		participants = toRedistributionParticipants(currentRedistribution) + 1;
-		tmpRedistribution = uint256(currentRedistribution);
-		tmpRedistribution &= (~maskRedistributionParticipants);
-		tmpRedistribution |= ((participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-
-		redistributions[redistributions.length-1] = bytes32(tmpRedistribution);
-
-		return true;
-	}
-
-	// Save the current total supply amount to the current redistribution period
-	function saveRedistributionSupply() private returns (bool) {
-		uint256 currentRedistribution;
-
-		currentRedistribution = uint256(redistributions[redistributions.length-1]);
-		currentRedistribution &= (~maskRedistributionValue);
-		currentRedistribution |= (totalSupply << shiftRedistributionValue);
-
-		redistributions[redistributions.length-1] = bytes32(currentRedistribution);
-		return true;
-	}
-
-	// Get the demurrage period of the current block number
-	function actualPeriod() public view returns (uint128) {
-		return uint128((block.timestamp - periodStart) / periodDuration + 1);
-	}
-
-	// Add an entered demurrage period to the redistribution array
-	function checkPeriod() private view returns (bytes32) {
-		bytes32 lastRedistribution;
-		uint256 currentPeriod;
-
-		lastRedistribution =  redistributions[redistributions.length-1];
-		currentPeriod = this.actualPeriod();
-		if (currentPeriod <= toRedistributionPeriod(lastRedistribution)) {
-			return bytes32(0x00);
-		}
-		return lastRedistribution;
-	}
-
-	// Deserialize the pemurrage period for the given account is participating in
-	function accountPeriod(address _account) public view returns (uint256) {
-		return (uint256(account[_account]) & maskAccountPeriod) >> shiftAccountPeriod;
-	}
-
-	// Save the given demurrage period as the currently participation period for the given address
-	function registerAccountPeriod(address _account, uint256 _period) private returns (bool) {
-		account[_account] &= bytes32(~maskAccountPeriod);
-		account[_account] |= bytes32((_period << shiftAccountPeriod) & maskAccountPeriod);
-		incrementRedistributionParticipants();
-		return true;
-	}
-
-	// Determine whether the unit number is rounded down, rounded up or evenly divides.
-	// Returns 0 if evenly distributed, or the remainder as a positive number
-	// A _numParts value 0 will be interpreted as the value 1
-	function remainder(uint256 _numParts, uint256 _sumWhole) public pure returns (uint256) {
-		uint256 unit;
-		uint256 truncatedResult;
-
-		if (_numParts == 0) { // no division by zero please
-			revert('ERR_NUMPARTS_ZERO');
-		}
-		require(_numParts < _sumWhole); // At least you are never LESS than the sum of your parts. Think about that.
-
-		unit = _sumWhole / _numParts;
-		truncatedResult = unit * _numParts;
-		return _sumWhole - truncatedResult;
-	}
-
-	// Returns the amount sent to the sink address
-	function applyDefaultRedistribution(bytes32 _redistribution) private returns (uint256) {
-		uint256 redistributionSupply;
-		uint256 redistributionPeriod;
-		uint256 unit;
-		uint256 truncatedResult;
-
-		redistributionSupply = toRedistributionSupply(_redistribution);
-
-		unit = (redistributionSupply * taxLevel) / 1000000;
-		truncatedResult = (unit * 1000000) / taxLevel;
-
-		if (truncatedResult < redistributionSupply) {
-			redistributionPeriod = toRedistributionPeriod(_redistribution); // since we reuse period here, can possibly be optimized by passing period instead
-			redistributions[redistributionPeriod-1] &= bytes32(~maskRedistributionParticipants); // just to be safe, zero out all participant count data, in this case there will be only one
-			redistributions[redistributionPeriod-1] |= bytes32(maskRedistributionIsFractional | (1 << shiftRedistributionParticipants));
-		}
-
-		increaseBaseBalance(sinkAddress, unit / ppmDivider);
-		return unit;
-	}
-
-	// sets the remainder bit for the given period and books the remainder to the sink address balance
-	// returns false if no change was made
-	function applyRemainderOnPeriod(uint256 _remainder, uint256 _period) private returns (bool) {
-		uint256 periodSupply;
-
-		if (_remainder == 0) {
-			return false;
-		}
-
-		// TODO: is this needed?
-		redistributions[_period-1] |= bytes32(maskRedistributionIsFractional);
-
-		periodSupply = toRedistributionSupply(redistributions[_period-1]);
-		increaseBaseBalance(sinkAddress, periodSupply - _remainder);
-		return true;
-	}
-
-
-	// Calculate and cache the demurrage value corresponding to the (period of the) time of the method call
-	function applyDemurrage() public returns (bool) {
-		uint128 epochPeriodCount;
-		uint128 periodCount;
-		uint256 lastDemurrageAmount;
-		uint256 newDemurrageAmount;
-
-		epochPeriodCount = actualPeriod();
-		periodCount = epochPeriodCount - demurragePeriod;
-		if (periodCount == 0) {
-			return false;
-		}
-		lastDemurrageAmount = demurrageAmount;
-		demurrageAmount = uint128(decayBy(lastDemurrageAmount, periodCount));
-		demurragePeriod = epochPeriodCount; 
-		emit Decayed(epochPeriodCount, periodCount, lastDemurrageAmount, demurrageAmount);
-		return true;
-	}
-
-	// Return timestamp of start of period threshold
-	function getPeriodTimeDelta(uint256 _periodCount) public view returns (uint256) {
-		return periodStart + (_periodCount * periodDuration);
-	}
-
-	// Amount of demurrage cycles inbetween the current timestamp and the given target time
-	function demurrageCycles(uint256 _target) public view returns (uint256) {
-		return (block.timestamp - _target) / 60;
-	}
-
-	// Recalculate the demurrage modifier for the new period
-	function changePeriod() public returns (bool) {
-		bytes32 currentRedistribution;
-		bytes32 nextRedistribution;
-		uint256 currentPeriod;
-		uint256 currentParticipants;
-		uint256 currentRemainder;
-		uint256 currentDemurrageAmount;
-		uint256 nextRedistributionDemurrage;
-		uint256 demurrageCounts;
-		uint256 periodTimestamp;
-		uint256 nextPeriod;
-
-		currentRedistribution = checkPeriod();
-		if (currentRedistribution == bytes32(0x00)) {
-			return false;
-		}
-
-		currentPeriod = toRedistributionPeriod(currentRedistribution);
-		nextPeriod = currentPeriod + 1;
-		periodTimestamp = getPeriodTimeDelta(currentPeriod);
-
-		applyDemurrage();
-		currentDemurrageAmount = demurrageAmount; 
-
-		demurrageCounts = demurrageCycles(periodTimestamp);
-		if (demurrageCounts > 0) {
-			nextRedistributionDemurrage = growBy(currentDemurrageAmount, demurrageCounts) / ppmDivider;
-		} else {
-			nextRedistributionDemurrage = currentDemurrageAmount / ppmDivider;
-		}
-		
-		nextRedistribution = toRedistribution(0, nextRedistributionDemurrage, totalSupply, nextPeriod);
-		redistributions.push(nextRedistribution);
-
-		//currentParticipants = toRedistributionParticipants(currentRedistribution);
-		//if (currentParticipants == 0) {
-		currentRemainder = applyDefaultRedistribution(currentRedistribution);
-		//} else {
-		//	currentRemainder = remainder(currentParticipants, totalSupply); // we can use totalSupply directly because it will always be the same as the recorded supply on the current redistribution
-		//	applyRemainderOnPeriod(currentRemainder, currentPeriod);
-		//}
-		emit Period(nextPeriod);
-		return true;
-	}
-
-	// Reverse a value reduced by demurrage by the given period to its original value
-	function growBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor + ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// Calculate a value reduced by demurrage by the given period
-	// TODO: higher precision if possible
-	function decayBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor - ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
-
-	// If the given account is participating in a period and that period has been crossed
-	// THEN increase the base value of the account with its share of the value reduction of the period
-	function applyRedistributionOnAccount(address _account) public returns (bool) {
-//		bytes32 periodRedistribution;
-//		uint256 supply;
-//		uint256 participants;
-//		uint256 baseValue;
-//		uint256 value;
-		uint256 period;
-//		uint256 demurrage;
-//	       
-		period = accountPeriod(_account);
-		if (period == 0 || period >= actualPeriod()) {
-			return false;
-		}
-//		periodRedistribution = redistributions[period-1];
-//		participants = toRedistributionParticipants(periodRedistribution);
-//		if (participants == 0) {
-//			return false;
-//		}
-//
-//		supply = toRedistributionSupply(periodRedistribution);
-//		demurrage = toRedistributionDemurrageModifier(periodRedistribution);
-//		baseValue = ((supply / participants) * (taxLevel / 1000000)) / ppmDivider;
-//		value = (baseValue * demurrage) / 1000000;
-//
-//		// zero out period for the account
-		account[_account] &= bytes32(~maskAccountPeriod); 
-//		increaseBaseBalance(_account, value);
-//
-//		emit Redistribution(_account, period, value);
-		return true;
-	}
-
-	// Inflates the given amount according to the current demurrage modifier
-	function toBaseAmount(uint256 _value) public view returns (uint256) {
-		//return (_value * ppmDivider * 1000000) / toDemurrageAmount(demurrageModifier);
-		return (_value * ppmDivider * 1000000) / demurrageAmount;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function approve(address _spender, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-
-		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		allowance[msg.sender][_spender] += baseValue;
-		emit Approval(msg.sender, _spender, _value);
-		return true;
-	}
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transfer(address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		result = transferBase(msg.sender, _to, baseValue);
-		emit Transfer(msg.sender, _to, _value);
-		return result;
-	}
-
-
-	// Implements ERC20, triggers tax and/or redistribution
-	function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
-		uint256 baseValue;
-		bool result;
-
-		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
-
-		baseValue = toBaseAmount(_value);
-		require(allowance[_from][msg.sender] >= baseValue);
-
-		result = transferBase(_from, _to, baseValue);
-		emit Transfer(_from, _to, _value);
-		return result;
-	}
-
-	// ERC20 transfer backend for transfer, transferFrom
-	function transferBase(address _from, address _to, uint256 _value) private returns (bool) {
-		uint256 period;
-
-		decreaseBaseBalance(_from, _value);
-		increaseBaseBalance(_to, _value);
-
-		period = actualPeriod();
-		if (_value >= minimumParticipantSpend && accountPeriod(_from) != period && _from != _to) {
-			registerAccountPeriod(_from, period);
-		}
-		return true;
-	}
-
-	// Implements EIP173
-	function transferOwnership(address _newOwner) public returns (bool) {
-		require(msg.sender == owner);
-		newOwner = _newOwner;
-	}
-
-	// Implements OwnedAccepter
-	function acceptOwnership() public returns (bool) {
-		address oldOwner;
-
-		require(msg.sender == newOwner);
-		oldOwner = owner; 
-		owner = newOwner;
-		newOwner = address(0);
-		emit OwnershipTransferred(oldOwner, owner);
-	}
-
-	// Implements EIP165
-	function supportsInterface(bytes4 _sum) public pure returns (bool) {
-		if (_sum == 0xc6bb4b70) { // ERC20
-			return true;
-		}
-		if (_sum == 0x449a52f8) { // Minter
-			return true;
-		}
-		if (_sum == 0x01ffc9a7) { // EIP165
-			return true;
-		}
-		if (_sum == 0x9493f8b2) { // EIP173
-			return true;
-		}
-		if (_sum == 0x37a47be4) { // OwnedAccepter
-			return true;
-		}
-		return false;
-	}
-}

solidity/DemurrageTokenSingleNocap.sol

@@ -1,36 +1,27 @@
-pragma solidity > 0.6.11;
+pragma solidity >= 0.8.0;
+
+
+import "aux/ABDKMath64x64.sol";
 
 // SPDX-License-Identifier: GPL-3.0-or-later
+contract DemurrageTokenSingleCap {
 
-contract DemurrageTokenSingleNocap {
+	struct redistributionItem {
+		uint32 period;
+		uint72 value;
+		uint64 demurrage;
+	}
+	redistributionItem[] public redistributions; // uint51(unused) | uint64(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
 
-	// Redistribution bit field, with associated shifts and masks
-	// (Uses sub-byte boundaries)
-	bytes32[] public redistributions; // uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	uint8 constant shiftRedistributionPeriod 	= 0;
-	uint256 constant maskRedistributionPeriod 	= 0x00000000000000000000000000000000000000000000000000000000ffffffff; // (1 << 32) - 1
-	uint8 constant shiftRedistributionValue 	= 32;
-	uint256 constant maskRedistributionValue	= 0x00000000000000000000000000000000000000ffffffffffffffffff00000000; // ((1 << 72) - 1) << 32
-	uint8 constant shiftRedistributionParticipants	= 104;
-	uint256 constant maskRedistributionParticipants	= 0x00000000000000000000000000000fffffffff00000000000000000000000000; // ((1 << 36) - 1) << 104
-	uint8 constant shiftRedistributionDemurrage	= 140;
-	uint256 constant maskRedistributionDemurrage	= 0x000000000000000000000000fffff00000000000000000000000000000000000; // ((1 << 20) - 1) << 140
-	uint8 constant shiftRedistributionIsFractional	= 255;
-	uint256 constant maskRedistributionIsFractional	= 0x8000000000000000000000000000000000000000000000000000000000000000; // 1 << 255
-
-	// Account bit field, with associated shifts and masks
-	// Mirrors structure of redistributions for consistency
-	mapping (address => bytes32) account; // uint152(unused) | uint32(period) | uint72(value)
-	uint8 constant shiftAccountValue		= 0;
-	uint256 constant maskAccountValue 		= 0x0000000000000000000000000000000000000000000000ffffffffffffffffff; // (1 << 72) - 1
-	uint8 constant shiftAccountPeriod		= 72;
-	uint256 constant maskAccountPeriod 		= 0x00000000000000000000000000000000000000ffffffff000000000000000000; // ((1 << 32) - 1) << 72
+	// Account balances
+	mapping (address => uint256) account;
 	
 	// Cached demurrage amount, ppm with 38 digit resolution
-	uint128 public demurrageAmount;
+	//uint128 public demurrageAmount;
+	int128 public demurrageAmount;
 
-	// Cached demurrage period; the period for which demurrageAmount was calculated
-	uint128 public demurragePeriod;
+	// Cached demurrage timestamp; the timestamp for which demurrageAmount was last calculated
+	uint256 public demurrageTimestamp;
 
 	// Implements EIP172
 	address public owner;
@@ -47,14 +38,27 @@ contract DemurrageTokenSingleNocap {
 	uint256 public decimals;
 
 	// Implements ERC20
-	uint256 public totalSupply;
+	//uint256 public totalSupply;
+	uint256 supply;
 
-	// Minimum amount of (demurraged) tokens an account must spend to participate in redistribution for a particular period
-	uint256 public minimumParticipantSpend;
+	// Last executed period
+	uint256 public lastPeriod;
+
+	// Last sink redistribution amount
+	uint256 public totalSink;
+
+	// Value of burnt tokens (burnt tokens do not decay)
+	uint256 public burned;
 
 	// 128 bit resolution of the demurrage divisor
 	// (this constant x 1000000 is contained within 128 bits)
-	uint256 constant ppmDivider = 100000000000000000000000000000000;
+	//uint256 constant nanoDivider = 100000000000000000000000000; // now nanodivider, 6 zeros less
+
+	// remaining decimal positions of nanoDivider to reach 38, equals precision in growth and decay
+	//uint256 constant growthResolutionFactor = 1000000000000;
+
+	// demurrage decimal width; 38 places
+	//uint256 public immutable resolutionFactor = nanoDivider * growthResolutionFactor; 
 
 	// Timestamp of start of periods (time which contract constructor was called)
 	uint256 public immutable periodStart;
@@ -63,8 +67,10 @@ contract DemurrageTokenSingleNocap {
 	uint256 public immutable periodDuration;
 
 	// Demurrage in ppm per minute
-	uint256 public immutable taxLevel;
-
+	//uint256 public immutable taxLevel;
+	// 64x64
+	int128 public taxLevel;
+		
 	// Addresses allowed to mint new tokens
 	mapping (address => bool) minter;
 
@@ -72,7 +78,14 @@ contract DemurrageTokenSingleNocap {
 	mapping (address => mapping (address => uint256 ) ) allowance; // holder -> spender -> amount (amount is subject to demurrage)
 
 	// Address to send unallocated redistribution tokens
-	address sinkAddress; 
+	address public sinkAddress; 
+
+	// timestamp when token contract expires
+	uint256 public expires;
+	bool expired;
+
+	// supply xap
+	uint256 public maxSupply;
 
 	// Implements ERC20
 	event Transfer(address indexed _from, address indexed _to, uint256 _value);
@@ -84,7 +97,7 @@ contract DemurrageTokenSingleNocap {
 	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value);
 
 	// New demurrage cache milestone calculated
-	event Decayed(uint256 indexed _period, uint256 indexed _periodCount, uint256 indexed _oldAmount, uint256 _newAmount);
+	event Decayed(uint256 indexed _period, uint256 indexed _periodCount, int128 indexed _oldAmount, int128 _newAmount);
 
 	// When a new period threshold has been crossed
 	event Period(uint256 _period);
@@ -93,12 +106,36 @@ contract DemurrageTokenSingleNocap {
 	event Redistribution(address indexed _account, uint256 indexed _period, uint256 _value);
 
 	// Temporary event used in development, will be removed on prod
-	event Debug(bytes32 _foo);
+	//event Debug(bytes32 _foo);
+	event Debug(int128 indexed _foo, uint256 indexed _bar);
+
+	// Emitted when tokens are burned
+	event Burn(address indexed _burner, uint256 _value);
 
 	// EIP173
 	event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); // EIP173
 
-	constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _taxLevelMinute, uint256 _periodMinutes, address _defaultSinkAddress) public {
+	event SealStateChange(uint256 _sealState);
+
+	event Expired(uint256 _timestamp);
+
+	event Cap(uint256 indexed _oldCap, uint256 _newCap);
+
+	// property sealing 
+	uint256 public sealState;
+	uint8 constant MINTER_STATE = 1;
+	uint8 constant SINK_STATE = 2;
+	uint8 constant EXPIRY_STATE = 4;
+	uint8 constant CAP_STATE = 8;
+	uint256 constant public maxSealState = 15;
+
+
+	constructor(string memory _name, string memory _symbol, uint8 _decimals, int128 _taxLevel, uint256 _periodMinutes, address _defaultSinkAddress) {
+		require(_taxLevel < (1 << 64));
+		redistributionItem memory initialRedistribution;
+
+		//require(ABDKMath64x64.toUInt(_taxLevel) == 0);
+
 		// ACL setup
 		owner = msg.sender;
 		minter[owner] = true;
@@ -109,21 +146,84 @@ contract DemurrageTokenSingleNocap {
 		decimals = _decimals;
 
 		// Demurrage setup
-		periodStart = block.timestamp;
+		demurrageTimestamp = block.timestamp;
+		periodStart = demurrageTimestamp;
 		periodDuration = _periodMinutes * 60;
-		demurrageAmount = uint128(ppmDivider * 1000000); // Represents 38 decimal places
-		demurragePeriod = 1;
-		taxLevel = _taxLevelMinute; // Represents 38 decimal places
-		bytes32 initialRedistribution = toRedistribution(0, 1000000, 0, 1);
+		demurrageAmount = ABDKMath64x64.fromUInt(1);
+
+		taxLevel = ABDKMath64x64.ln(_taxLevel);
+		initialRedistribution = toRedistribution(0, demurrageAmount, 0, 1);
 		redistributions.push(initialRedistribution);
 
 		// Misc settings
 		sinkAddress = _defaultSinkAddress;
-		minimumParticipantSpend = 10 ** uint256(_decimals);
+	}
+
+	function seal(uint256 _state) public returns(uint256) {
+		require(_state < 16, 'ERR_INVALID_STATE');
+		require(_state & sealState == 0, 'ERR_ALREADY_LOCKED');
+		sealState |= _state;
+		emit SealStateChange(sealState);
+		return uint256(sealState);
+	}
+
+	function isSealed(uint256 _state) public returns(bool) {
+		require(_state < maxSealState);
+		if (_state == 0) {
+			return sealState == maxSealState;
+		}
+		return _state & sealState == _state;
+	}
+
+	function setExpirePeriod(uint256 _expirePeriod) public {
+		uint256 r;
+
+		require(!isSealed(EXPIRY_STATE));
+		require(!expired);
+		require(msg.sender == owner);
+		r = periodStart + (_expirePeriod * periodDuration);
+		require(r > expires);
+		expires = r;
+	}
+	
+	function setMaxSupply(uint256 _cap) public {
+		require(!isSealed(CAP_STATE));
+		require(msg.sender == owner);
+		require(_cap > totalSupply());
+		emit Cap(maxSupply, _cap);
+		maxSupply = _cap;
+	}
+
+	// Change sink address for redistribution
+	function setSinkAddress(address _sinkAddress) public {
+		require(!isSealed(SINK_STATE));
+		require(msg.sender == owner);
+		sinkAddress = _sinkAddress;
+	}
+
+	// Expire the contract if expire is set and we have gone over the threshold.
+	// Finalizes demurrage up to the timestamp of the expiry. 
+	// The first approve, transfer or transferFrom call that hits the ex == 2 will get the tx mined. but without the actual effect. Otherwise we would have to wait until an external egent called applyExpiry to get the correct final balance.
+	function applyExpiry() public returns(uint8) {
+		if (expired) {
+			return 1;
+		}
+		if (expires == 0) {
+			return 0;
+		}
+		if (block.timestamp >= expires) {
+			applyDemurrageLimited(expires - demurrageTimestamp / 60);
+			expired = true;
+			emit Expired(block.timestamp);
+			changePeriod();
+			return 2;
+		}
+		return 0;
 	}
 
 	// Given address will be allowed to call the mintTo() function
 	function addMinter(address _minter) public returns (bool) {
+		require(!isSealed(MINTER_STATE));
 		require(msg.sender == owner);
 		minter[_minter] = true;
 		return true;
@@ -131,6 +231,7 @@ contract DemurrageTokenSingleNocap {
 
 	// Given address will no longer be allowed to call the mintTo() function
 	function removeMinter(address _minter) public returns (bool) {
+		require(!isSealed(MINTER_STATE));
 		require(msg.sender == owner || _minter == msg.sender);
 		minter[_minter] = false;
 		return true;
@@ -138,22 +239,22 @@ contract DemurrageTokenSingleNocap {
 
 	/// Implements ERC20
 	function balanceOf(address _account) public view returns (uint256) {
-		uint256 baseBalance;
-		uint256 currentDemurragedAmount;
+		int128 baseBalance;
+		int128 currentDemurragedAmount;
 		uint256 periodCount;
+		uint8 expiryState;
 
-		baseBalance = baseBalanceOf(_account);
+		baseBalance = ABDKMath64x64.fromUInt(baseBalanceOf(_account));
 
-		periodCount = actualPeriod() - demurragePeriod; 
+		periodCount = getMinutesDelta(demurrageTimestamp);
 
-		currentDemurragedAmount = uint128(decayBy(demurrageAmount, periodCount));
-
-		return (baseBalance * currentDemurragedAmount) / (ppmDivider * 1000000);
+		currentDemurragedAmount = ABDKMath64x64.mul(baseBalance, demurrageAmount);
+		return decayBy(ABDKMath64x64.toUInt(currentDemurragedAmount), periodCount);
 	}
 
-	/// Balance unmodified by demurrage
+	// Balance unmodified by demurrage
 	function baseBalanceOf(address _account) public view returns (uint256) {
-		return uint256(account[_account]) & maskAccountValue;
+		return account[_account];
 	}
 
 	/// Increases base balance for a single account
@@ -169,11 +270,7 @@ contract DemurrageTokenSingleNocap {
 		}
 
 		oldBalance = baseBalanceOf(_account);
-		newBalance = oldBalance + _delta;
-		require(uint160(newBalance) > uint160(oldBalance), 'ERR_WOULDWRAP'); // revert if increase would result in a wrapped value
-		workAccount &= (~maskAccountValue); 
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
+		account[_account] = oldBalance + _delta;
 		return true;
 	}
 
@@ -191,10 +288,7 @@ contract DemurrageTokenSingleNocap {
 
 		oldBalance = baseBalanceOf(_account);	
 		require(oldBalance >= _delta, 'ERR_OVERSPEND'); // overspend guard
-		newBalance = oldBalance - _delta;
-		workAccount &= (~maskAccountValue);
-		workAccount |= (newBalance & maskAccountValue);
-		account[_account] = bytes32(workAccount);
+		account[_account] = oldBalance - _delta;
 		return true;
 	}
 
@@ -203,11 +297,15 @@ contract DemurrageTokenSingleNocap {
 	function mintTo(address _beneficiary, uint256 _amount) external returns (bool) {
 		uint256 baseAmount;
 
-		require(minter[msg.sender]);
+		require(applyExpiry() == 0);
+		require(minter[msg.sender], 'ERR_ACCESS');
+changePeriod();
+		if (maxSupply > 0) {
+			require(supply + _amount <= maxSupply);
+		}
+		supply += _amount;
 
-		changePeriod();
-		baseAmount = _amount;
-		totalSupply += _amount;
+		baseAmount = toBaseAmount(_amount);
 		increaseBaseBalance(_beneficiary, baseAmount);
 		emit Mint(msg.sender, _beneficiary, _amount);
 		saveRedistributionSupply();
@@ -215,35 +313,35 @@ contract DemurrageTokenSingleNocap {
 	}
 
 	// Deserializes the redistribution word
-	// uint1(isFractional) | uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
-	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) private pure returns(bytes32) {
-		bytes32 redistribution;
+	function toRedistribution(uint256 _participants, int128 _demurrageModifier, uint256 _value, uint256 _period) public pure returns(redistributionItem memory) {
+		redistributionItem memory redistribution;
 
-		redistribution |= bytes32((_demurrageModifierPpm << shiftRedistributionDemurrage) & maskRedistributionDemurrage);
-		redistribution |= bytes32((_participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-		redistribution |= bytes32((_value << shiftRedistributionValue) & maskRedistributionValue); 
-		redistribution |= bytes32(_period & maskRedistributionPeriod);
+		redistribution.period = uint32(_period);
+		redistribution.value = uint72(_value);
+		redistribution.demurrage = uint64(uint128(_demurrageModifier) & 0xffffffffffffffff);
 		return redistribution;
+
 	}
 
 	// Serializes the demurrage period part of the redistribution word
-	function toRedistributionPeriod(bytes32 redistribution) public pure returns (uint256) {
-		return uint256(redistribution) & maskRedistributionPeriod;
+	function toRedistributionPeriod(redistributionItem memory _redistribution) public pure returns (uint256) {
+		return uint256(_redistribution.period);
 	}
 
 	// Serializes the supply part of the redistribution word
-	function toRedistributionSupply(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionValue) >> shiftRedistributionValue;
+	function toRedistributionSupply(redistributionItem memory _redistribution) public pure returns (uint256) {
+		return uint256(_redistribution.value);
 	}
 
 	// Serializes the number of participants part of the redistribution word
-	function toRedistributionParticipants(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionParticipants) >> shiftRedistributionParticipants;
-	}
+	function toRedistributionDemurrageModifier(redistributionItem memory _redistribution) public pure returns (int128) {
+		int128 r;
 
-	// Serializes the number of participants part of the redistribution word
-	function toRedistributionDemurrageModifier(bytes32 redistribution) public pure returns (uint256) {
-		return (uint256(redistribution) & maskRedistributionDemurrage) >> shiftRedistributionDemurrage;
+		r = int128(int64(_redistribution.demurrage) & int128(0x0000000000000000ffffffffffffffff));
+		if (r == 0) {
+			r = ABDKMath64x64.fromUInt(1);
+		}
+		return r;
 	}
 
 	// Client accessor to the redistributions array length
@@ -251,32 +349,16 @@ contract DemurrageTokenSingleNocap {
 		return redistributions.length;
 	}
 
-	// Add number of participants for the current redistribution period by one
-	function incrementRedistributionParticipants() private returns (bool) {
-		bytes32 currentRedistribution;
-		uint256 tmpRedistribution;
-		uint256 participants;
-
-		currentRedistribution = redistributions[redistributions.length-1];
-		participants = toRedistributionParticipants(currentRedistribution) + 1;
-		tmpRedistribution = uint256(currentRedistribution);
-		tmpRedistribution &= (~maskRedistributionParticipants);
-		tmpRedistribution |= ((participants << shiftRedistributionParticipants) & maskRedistributionParticipants);
-
-		redistributions[redistributions.length-1] = bytes32(tmpRedistribution);
-
-		return true;
-	}
-
 	// Save the current total supply amount to the current redistribution period
 	function saveRedistributionSupply() private returns (bool) {
-		uint256 currentRedistribution;
+		redistributionItem memory currentRedistribution;
+		uint256 grownSupply;
 
-		currentRedistribution = uint256(redistributions[redistributions.length-1]);
-		currentRedistribution &= (~maskRedistributionValue);
-		currentRedistribution |= (totalSupply << shiftRedistributionValue);
+		grownSupply = totalSupply();
+		currentRedistribution = redistributions[redistributions.length-1];
+		currentRedistribution.value = uint72(grownSupply);
 
-		redistributions[redistributions.length-1] = bytes32(currentRedistribution);
+		redistributions[redistributions.length-1] = currentRedistribution;
 		return true;
 	}
 
@@ -285,106 +367,126 @@ contract DemurrageTokenSingleNocap {
 		return uint128((block.timestamp - periodStart) / periodDuration + 1);
 	}
 
-	// Add an entered demurrage period to the redistribution array
-	function checkPeriod() private view returns (bytes32) {
-		bytes32 lastRedistribution;
+	// Retrieve next redistribution if the period threshold has been crossed
+	function checkPeriod() private view returns (redistributionItem memory) {
+		redistributionItem memory lastRedistribution;
+		redistributionItem memory emptyRedistribution;
 		uint256 currentPeriod;
 
-		lastRedistribution =  redistributions[redistributions.length-1];
+		lastRedistribution =  redistributions[lastPeriod];
 		currentPeriod = this.actualPeriod();
 		if (currentPeriod <= toRedistributionPeriod(lastRedistribution)) {
-			return bytes32(0x00);
+			return emptyRedistribution;
 		}
 		return lastRedistribution;
 	}
 
-	// Deserialize the pemurrage period for the given account is participating in
-	function accountPeriod(address _account) public view returns (uint256) {
-		return (uint256(account[_account]) & maskAccountPeriod) >> shiftAccountPeriod;
+	function getDistribution(uint256 _supply, int128 _demurrageAmount) public view returns (uint256) {
+		int128 difference;
+
+		difference = ABDKMath64x64.mul(ABDKMath64x64.fromUInt(_supply), ABDKMath64x64.sub(ABDKMath64x64.fromUInt(1), _demurrageAmount));
+		return _supply - ABDKMath64x64.toUInt(difference);
+			
 	}
 
-	// Save the given demurrage period as the currently participation period for the given address
-	function registerAccountPeriod(address _account, uint256 _period) private returns (bool) {
-		account[_account] &= bytes32(~maskAccountPeriod);
-		account[_account] |= bytes32((_period << shiftAccountPeriod) & maskAccountPeriod);
-		incrementRedistributionParticipants();
-		return true;
-	}
+	function getDistributionFromRedistribution(redistributionItem memory _redistribution) public returns (uint256) {
+		uint256 redistributionSupply;
+		int128 redistributionDemurrage;
 
-	// Determine whether the unit number is rounded down, rounded up or evenly divides.
-	// Returns 0 if evenly distributed, or the remainder as a positive number
-	// A _numParts value 0 will be interpreted as the value 1
-	function remainder(uint256 _numParts, uint256 _sumWhole) public pure returns (uint256) {
-		uint256 unit;
-		uint256 truncatedResult;
-
-		if (_numParts == 0) { // no division by zero please
-			revert('ERR_NUMPARTS_ZERO');
-		}
-		require(_numParts < _sumWhole); // At least you are never LESS than the sum of your parts. Think about that.
-
-		unit = _sumWhole / _numParts;
-		truncatedResult = unit * _numParts;
-		return _sumWhole - truncatedResult;
+		redistributionSupply = toRedistributionSupply(_redistribution);
+		redistributionDemurrage = toRedistributionDemurrageModifier(_redistribution);
+		return getDistribution(redistributionSupply, redistributionDemurrage);
 	}
 
 	// Returns the amount sent to the sink address
-	function applyDefaultRedistribution(bytes32 _redistribution) private returns (uint256) {
-		uint256 redistributionSupply;
-		uint256 redistributionPeriod;
+	function applyDefaultRedistribution(redistributionItem memory _redistribution) private returns (uint256) {
 		uint256 unit;
-		uint256 truncatedResult;
-
-		redistributionSupply = toRedistributionSupply(_redistribution);
-
-		unit = (redistributionSupply * taxLevel) / 1000000;
-		truncatedResult = (unit * 1000000) / taxLevel;
-
-		if (truncatedResult < redistributionSupply) {
-			redistributionPeriod = toRedistributionPeriod(_redistribution); // since we reuse period here, can possibly be optimized by passing period instead
-			redistributions[redistributionPeriod-1] &= bytes32(~maskRedistributionParticipants); // just to be safe, zero out all participant count data, in this case there will be only one
-			redistributions[redistributionPeriod-1] |= bytes32(maskRedistributionIsFractional | (1 << shiftRedistributionParticipants));
-		}
-
-		increaseBaseBalance(sinkAddress, unit / ppmDivider);
+		uint256 baseUnit;
+	
+		unit = totalSupply() - getDistributionFromRedistribution(_redistribution);	
+		baseUnit = toBaseAmount(unit) - totalSink;
+		increaseBaseBalance(sinkAddress, baseUnit);
+		emit Redistribution(sinkAddress, _redistribution.period, unit);
+		lastPeriod += 1;
+		totalSink += baseUnit;
 		return unit;
 	}
 
-	// sets the remainder bit for the given period and books the remainder to the sink address balance
-	// returns false if no change was made
-	function applyRemainderOnPeriod(uint256 _remainder, uint256 _period) private returns (bool) {
-		uint256 periodSupply;
+	// Recalculate the demurrage modifier for the new period
+	// Note that the supply for the consecutive period will be taken at the time of code execution, and thus not necessarily at the time when the redistribution period threshold was crossed.
+	function changePeriod() public returns (bool) {
+		redistributionItem memory currentRedistribution;
+		redistributionItem memory nextRedistribution;
+		redistributionItem memory lastRedistribution;
+		uint256 currentPeriod;
+		int128 lastDemurrageAmount;
+		int128 nextRedistributionDemurrage;
+		uint256 demurrageCounts;
+		uint256 nextPeriod;
 
-		if (_remainder == 0) {
+		applyDemurrage();
+		currentRedistribution = checkPeriod();
+		if (isEmptyRedistribution(currentRedistribution)) {
 			return false;
 		}
 
-		// TODO: is this needed?
-		redistributions[_period-1] |= bytes32(maskRedistributionIsFractional);
+		// calculate the decay from previous redistributino
+		lastRedistribution = redistributions[lastPeriod];
+		currentPeriod = toRedistributionPeriod(currentRedistribution);
+		nextPeriod = currentPeriod + 1;
+		lastDemurrageAmount = toRedistributionDemurrageModifier(lastRedistribution);
+		demurrageCounts = (periodDuration * currentPeriod) / 60;
+		// TODO refactor decayby to take int128 then DRY with it
+		nextRedistributionDemurrage = ABDKMath64x64.exp(ABDKMath64x64.mul(taxLevel, ABDKMath64x64.fromUInt(demurrageCounts)));
+		nextRedistribution = toRedistribution(0, nextRedistributionDemurrage, totalSupply(), nextPeriod);
+		redistributions.push(nextRedistribution);
 
-		periodSupply = toRedistributionSupply(redistributions[_period-1]);
-		increaseBaseBalance(sinkAddress, periodSupply - _remainder);
+		applyDefaultRedistribution(nextRedistribution);
+		emit Period(nextPeriod);
 		return true;
 	}
 
+	// Calculate the time delta in whole minutes passed between given timestamp and current timestamp
+	function getMinutesDelta(uint256 _lastTimestamp) public view returns (uint256) {
+		return (block.timestamp - _lastTimestamp) / 60;
+	}
 
 	// Calculate and cache the demurrage value corresponding to the (period of the) time of the method call
-	function applyDemurrage() public returns (bool) {
-		uint128 epochPeriodCount;
-		uint128 periodCount;
-		uint256 lastDemurrageAmount;
-		uint256 newDemurrageAmount;
+	function applyDemurrage() public returns (uint256) {
+		return applyDemurrageLimited(0);
+	}
 
-		epochPeriodCount = actualPeriod();
-		periodCount = epochPeriodCount - demurragePeriod;
+	// returns true if expired
+	function applyDemurrageLimited(uint256 _rounds) public returns (uint256) {
+		int128 v;
+		uint256 periodCount;
+		int128 periodPoint;
+		int128 lastDemurrageAmount;
+
+		if (expired) {
+			return 0; 
+		}
+
+		periodCount = getMinutesDelta(demurrageTimestamp);
 		if (periodCount == 0) {
-			return false;
+			return 0;
 		}
 		lastDemurrageAmount = demurrageAmount;
-		demurrageAmount = uint128(decayBy(lastDemurrageAmount, periodCount));
-		demurragePeriod = epochPeriodCount; 
-		emit Decayed(epochPeriodCount, periodCount, lastDemurrageAmount, demurrageAmount);
-		return true;
+	
+		// safety limit for exponential calculation to ensure that we can always
+		// execute this code no matter how much time passes.			
+		if (_rounds > 0 && _rounds < periodCount) {
+			periodCount = _rounds;
+		}
+
+		periodPoint = ABDKMath64x64.fromUInt(periodCount);
+		v = ABDKMath64x64.mul(taxLevel, periodPoint);
+		v = ABDKMath64x64.exp(v);
+		demurrageAmount = ABDKMath64x64.mul(demurrageAmount, v);
+
+		demurrageTimestamp = demurrageTimestamp + (periodCount * 60);
+		emit Decayed(demurrageTimestamp, periodCount, lastDemurrageAmount, demurrageAmount);
+		return periodCount;
 	}
 
 	// Return timestamp of start of period threshold
@@ -397,141 +499,106 @@ contract DemurrageTokenSingleNocap {
 		return (block.timestamp - _target) / 60;
 	}
 
-	// Recalculate the demurrage modifier for the new period
-	function changePeriod() public returns (bool) {
-		bytes32 currentRedistribution;
-		bytes32 nextRedistribution;
-		uint256 currentPeriod;
-		uint256 currentParticipants;
-		uint256 currentRemainder;
-		uint256 currentDemurrageAmount;
-		uint256 nextRedistributionDemurrage;
-		uint256 demurrageCounts;
-		uint256 periodTimestamp;
-		uint256 nextPeriod;
-
-		currentRedistribution = checkPeriod();
-		if (currentRedistribution == bytes32(0x00)) {
+	function isEmptyRedistribution(redistributionItem memory _redistribution) public pure returns(bool) {
+		if (_redistribution.period > 0) {
 			return false;
 		}
-
-		currentPeriod = toRedistributionPeriod(currentRedistribution);
-		nextPeriod = currentPeriod + 1;
-		periodTimestamp = getPeriodTimeDelta(currentPeriod);
-
-		applyDemurrage();
-		currentDemurrageAmount = demurrageAmount; 
-
-		demurrageCounts = demurrageCycles(periodTimestamp);
-		if (demurrageCounts > 0) {
-			nextRedistributionDemurrage = growBy(currentDemurrageAmount, demurrageCounts) / ppmDivider;
-		} else {
-			nextRedistributionDemurrage = currentDemurrageAmount / ppmDivider;
+		if (_redistribution.value > 0) {
+			return false;
+		}
+		if (_redistribution.demurrage > 0) {
+			return false;
 		}
-		
-		nextRedistribution = toRedistribution(0, nextRedistributionDemurrage, totalSupply, nextPeriod);
-		redistributions.push(nextRedistribution);
-
-		//currentParticipants = toRedistributionParticipants(currentRedistribution);
-		//if (currentParticipants == 0) {
-		currentRemainder = applyDefaultRedistribution(currentRedistribution);
-		//} else {
-		//	currentRemainder = remainder(currentParticipants, totalSupply); // we can use totalSupply directly because it will always be the same as the recorded supply on the current redistribution
-		//	applyRemainderOnPeriod(currentRemainder, currentPeriod);
-		//}
-		emit Period(nextPeriod);
 		return true;
 	}
 
-	// Reverse a value reduced by demurrage by the given period to its original value
-	function growBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
-
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor + ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
-	}
 
 	// Calculate a value reduced by demurrage by the given period
-	// TODO: higher precision if possible
-	function decayBy(uint256 _value, uint256 _period) public view returns (uint256) {
-		uint256 valueFactor;
-		uint256 truncatedTaxLevel;
-	      
-		valueFactor = 1000000;
-		truncatedTaxLevel = taxLevel / ppmDivider;
+	function decayBy(uint256 _value, uint256 _period)  public view returns (uint256) {
+		int128 valuePoint;
+		int128 periodPoint;
+		int128 v;
+	
+		valuePoint = ABDKMath64x64.fromUInt(_value);
+		periodPoint = ABDKMath64x64.fromUInt(_period);
 
-		for (uint256 i = 0; i < _period; i++) {
-			valueFactor = valueFactor - ((valueFactor * truncatedTaxLevel) / 1000000);
-		}
-		return (valueFactor * _value) / 1000000;
+		v = ABDKMath64x64.mul(taxLevel, periodPoint);
+		v = ABDKMath64x64.exp(v);
+		v = ABDKMath64x64.mul(valuePoint, v);
+		return ABDKMath64x64.toUInt(v);
 	}
 
-	// If the given account is participating in a period and that period has been crossed
-	// THEN increase the base value of the account with its share of the value reduction of the period
-	function applyRedistributionOnAccount(address _account) public returns (bool) {
-//		bytes32 periodRedistribution;
-//		uint256 supply;
-//		uint256 participants;
-//		uint256 baseValue;
-//		uint256 value;
-		uint256 period;
-//		uint256 demurrage;
-//	       
-		period = accountPeriod(_account);
-		if (period == 0 || period >= actualPeriod()) {
-			return false;
-		}
-//		periodRedistribution = redistributions[period-1];
-//		participants = toRedistributionParticipants(periodRedistribution);
-//		if (participants == 0) {
-//			return false;
-//		}
-//
-//		supply = toRedistributionSupply(periodRedistribution);
-//		demurrage = toRedistributionDemurrageModifier(periodRedistribution);
-//		baseValue = ((supply / participants) * (taxLevel / 1000000)) / ppmDivider;
-//		value = (baseValue * demurrage) / 1000000;
-//
-//		// zero out period for the account
-		account[_account] &= bytes32(~maskAccountPeriod); 
-//		increaseBaseBalance(_account, value);
-//
-//		emit Redistribution(_account, period, value);
-		return true;
-	}
 
 	// Inflates the given amount according to the current demurrage modifier
 	function toBaseAmount(uint256 _value) public view returns (uint256) {
-		//return (_value * ppmDivider * 1000000) / toDemurrageAmount(demurrageModifier);
-		return (_value * ppmDivider * 1000000) / demurrageAmount;
+		int128 r;
+		r = ABDKMath64x64.div(ABDKMath64x64.fromUInt(_value), demurrageAmount);
+		return ABDKMath64x64.toUInt(r);
 	}
 
 	// Implements ERC20, triggers tax and/or redistribution
 	function approve(address _spender, uint256 _value) public returns (bool) {
 		uint256 baseValue;
+		uint8 ex;
 
+		ex = applyExpiry();
+		if (ex == 2) {
+			return false;	
+		} else if (ex > 0) {
+			revert('EXPIRED');
+		}
+		if (allowance[msg.sender][_spender] > 0) {
+			require(_value == 0, 'ZERO_FIRST');
+		}
+		
 		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
 
 		baseValue = toBaseAmount(_value);
-		allowance[msg.sender][_spender] += baseValue;
+		allowance[msg.sender][_spender] = baseValue;
 		emit Approval(msg.sender, _spender, _value);
 		return true;
 	}
 
+	// Reduce allowance by amount
+	function decreaseAllowance(address _spender, uint256 _value) public returns (bool) {
+		uint256 baseValue;
+
+		baseValue = toBaseAmount(_value);
+		require(allowance[msg.sender][_spender] >= baseValue);
+		
+		changePeriod();
+
+		allowance[msg.sender][_spender] -= baseValue;
+		emit Approval(msg.sender, _spender, allowance[msg.sender][_spender]);
+		return true;
+	}
+
+	// Increase allowance by amount
+	function increaseAllowance(address _spender, uint256 _value) public returns (bool) {
+		uint256 baseValue;
+
+		changePeriod();
+
+		baseValue = toBaseAmount(_value);
+
+		allowance[msg.sender][_spender] += baseValue;
+		emit Approval(msg.sender, _spender, allowance[msg.sender][_spender]);
+		return true;
+	}
+
 	// Implements ERC20, triggers tax and/or redistribution
 	function transfer(address _to, uint256 _value) public returns (bool) {
 		uint256 baseValue;
 		bool result;
+		uint8 ex;
 
+		ex = applyExpiry();
+		if (ex == 2) {
+			return false;	
+		} else if (ex > 0) {
+			revert('EXPIRED');
+		}
 		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
 
 		baseValue = toBaseAmount(_value);
 		result = transferBase(msg.sender, _to, baseValue);
@@ -539,19 +606,26 @@ contract DemurrageTokenSingleNocap {
 		return result;
 	}
 
-
 	// Implements ERC20, triggers tax and/or redistribution
 	function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
 		uint256 baseValue;
 		bool result;
+		uint8 ex;
 
+		ex = applyExpiry();
+		if (ex == 2) {
+			return false;	
+		} else if (ex > 0) {
+			revert('EXPIRED');
+		}
 		changePeriod();
-		//applyRedistributionOnAccount(msg.sender);
 
 		baseValue = toBaseAmount(_value);
 		require(allowance[_from][msg.sender] >= baseValue);
 
+		allowance[_from][msg.sender] -= baseValue;
 		result = transferBase(_from, _to, baseValue);
+
 		emit Transfer(_from, _to, _value);
 		return result;
 	}
@@ -563,10 +637,6 @@ contract DemurrageTokenSingleNocap {
 		decreaseBaseBalance(_from, _value);
 		increaseBaseBalance(_to, _value);
 
-		period = actualPeriod();
-		if (_value >= minimumParticipantSpend && accountPeriod(_from) != period && _from != _to) {
-			registerAccountPeriod(_from, period);
-		}
 		return true;
 	}
 
@@ -587,6 +657,30 @@ contract DemurrageTokenSingleNocap {
 		emit OwnershipTransferred(oldOwner, owner);
 	}
 
+	// Explicitly and irretrievably burn tokens
+	// Only token minters can burn tokens
+	function burn(uint256 _value) public {
+		require(applyExpiry() == 0);
+		require(minter[msg.sender]);
+		require(_value <= account[msg.sender]);
+		uint256 _delta = toBaseAmount(_value);
+
+		//applyDemurrage();
+		decreaseBaseBalance(msg.sender, _delta);
+		burned += _value;
+		emit Burn(msg.sender, _value);
+	}
+
+	// Implements ERC20
+	function totalSupply() public view returns (uint256) {
+		return supply - burned;
+	}
+
+	// Return total number of burned tokens
+	function totalBurned() public view returns (uint256) {
+		return burned;
+	}
+
 	// Implements EIP165
 	function supportsInterface(bytes4 _sum) public pure returns (bool) {
 		if (_sum == 0xc6bb4b70) { // ERC20

solidity/Makefile

@@ -1,30 +1,13 @@
 SOLC = /usr/bin/solc
 
-all: multi single
-
-multi_nocap:
-	$(SOLC) DemurrageTokenMultiNocap.sol --abi --evm-version byzantium | awk 'NR>3' > DemurrageTokenMultiNocap.json
-	$(SOLC) DemurrageTokenMultiNocap.sol --bin --evm-version byzantium | awk 'NR>3' > DemurrageTokenMultiNocap.bin
-	truncate -s -1 DemurrageTokenMultiNocap.bin
-
-multi_cap:
-	$(SOLC) DemurrageTokenMultiCap.sol --abi --evm-version byzantium | awk 'NR>3' > DemurrageTokenMultiCap.json
-	$(SOLC) DemurrageTokenMultiCap.sol --bin --evm-version byzantium | awk 'NR>3' > DemurrageTokenMultiCap.bin
-	truncate -s -1 DemurrageTokenMultiCap.bin
-
-multi: multi_nocap multi_cap
+all: single_nocap
 
 single_nocap:
-	$(SOLC) DemurrageTokenSingleNocap.sol --abi --evm-version byzantium | awk 'NR>3' > DemurrageTokenSingleNocap.json
-	$(SOLC) DemurrageTokenSingleNocap.sol --bin --evm-version byzantium | awk 'NR>3' > DemurrageTokenSingleNocap.bin
+	$(SOLC) DemurrageTokenSingleNocap.sol --abi --evm-version byzantium | awk 'NR==4' > DemurrageTokenSingleNocap.json
+	$(SOLC) DemurrageTokenSingleNocap.sol --bin --evm-version byzantium | awk 'NR==4' > DemurrageTokenSingleNocap.bin
 	truncate -s -1 DemurrageTokenSingleNocap.bin
 
-single_cap:
-	$(SOLC) DemurrageTokenSingleCap.sol --abi --evm-version byzantium | awk 'NR>3' > DemurrageTokenSingleCap.json
-	$(SOLC) DemurrageTokenSingleCap.sol --bin --evm-version byzantium | awk 'NR>3' > DemurrageTokenSingleCap.bin
-	truncate -s -1 DemurrageTokenSingleCap.bin
-
-single: single_nocap single_cap
+single: single_nocap
 
 test: all
 	python ../python/tests/test_basic.py
@@ -33,6 +16,7 @@ test: all
 	python ../python/tests/test_pure.py
 
 install: all
-	cp -v DemurrageToken*.{json,bin} ../python/erc20_demurrage_token/data/
+	cp -v DemurrageToken*.json ../python/erc20_demurrage_token/data/
+	cp -v DemurrageToken*.bin ../python/erc20_demurrage_token/data/
 	
 .PHONY: test install

solidity/aux/ABDKMath64x64.sol

@@ -0,0 +1,752 @@
+// SPDX-License-Identifier: BSD-4-Clause
+/*
+ * ABDK Math 64.64 Smart Contract Library.  Copyright © 2019 by ABDK Consulting.
+ * Author: Mikhail Vladimirov <mikhail.vladimirov@gmail.com>
+ */
+pragma solidity ^0.8.0;
+
+/**
+ * Smart contract library of mathematical functions operating with signed
+ * 64.64-bit fixed point numbers.  Signed 64.64-bit fixed point number is
+ * basically a simple fraction whose numerator is signed 128-bit integer and
+ * denominator is 2^64.  As long as denominator is always the same, there is no
+ * need to store it, thus in Solidity signed 64.64-bit fixed point numbers are
+ * represented by int128 type holding only the numerator.
+ */
+library ABDKMath64x64 {
+  /*
+   * Minimum value signed 64.64-bit fixed point number may have. 
+   */
+  int128 private constant MIN_64x64 = -0x80000000000000000000000000000000;
+
+  /*
+   * Maximum value signed 64.64-bit fixed point number may have. 
+   */
+  int128 private constant MAX_64x64 = 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;
+
+  /**
+   * Convert signed 256-bit integer number into signed 64.64-bit fixed point
+   * number.  Revert on overflow.
+   *
+   * @param x signed 256-bit integer number
+   * @return signed 64.64-bit fixed point number
+   */
+  function fromInt (int256 x) internal pure returns (int128) {
+    unchecked {
+      require (x >= -0x8000000000000000 && x <= 0x7FFFFFFFFFFFFFFF);
+      return int128 (x << 64);
+    }
+  }
+
+  /**
+   * Convert signed 64.64 fixed point number into signed 64-bit integer number
+   * rounding down.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64-bit integer number
+   */
+  function toInt (int128 x) internal pure returns (int64) {
+    unchecked {
+      return int64 (x >> 64);
+    }
+  }
+
+  /**
+   * Convert unsigned 256-bit integer number into signed 64.64-bit fixed point
+   * number.  Revert on overflow.
+   *
+   * @param x unsigned 256-bit integer number
+   * @return signed 64.64-bit fixed point number
+   */
+  function fromUInt (uint256 x) internal pure returns (int128) {
+    unchecked {
+      require (x <= 0x7FFFFFFFFFFFFFFF);
+      return int128 (int256 (x << 64));
+    }
+  }
+
+  /**
+   * Convert signed 64.64 fixed point number into unsigned 64-bit integer
+   * number rounding down.  Revert on underflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return unsigned 64-bit integer number
+   */
+  function toUInt (int128 x) internal pure returns (uint64) {
+    unchecked {
+      require (x >= 0);
+      return uint64 (uint128 (x >> 64));
+    }
+  }
+
+  /**
+   * Convert signed 128.128 fixed point number into signed 64.64-bit fixed point
+   * number rounding down.  Revert on overflow.
+   *
+   * @param x signed 128.128-bin fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function from128x128 (int256 x) internal pure returns (int128) {
+    unchecked {
+      int256 result = x >> 64;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Convert signed 64.64 fixed point number into signed 128.128 fixed point
+   * number.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 128.128 fixed point number
+   */
+  function to128x128 (int128 x) internal pure returns (int256) {
+    unchecked {
+      return int256 (x) << 64;
+    }
+  }
+
+  /**
+   * Calculate x + y.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function add (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      int256 result = int256(x) + y;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate x - y.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function sub (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      int256 result = int256(x) - y;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate x * y rounding down.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function mul (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      int256 result = int256(x) * y >> 64;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate x * y rounding towards zero, where x is signed 64.64 fixed point
+   * number and y is signed 256-bit integer number.  Revert on overflow.
+   *
+   * @param x signed 64.64 fixed point number
+   * @param y signed 256-bit integer number
+   * @return signed 256-bit integer number
+   */
+  function muli (int128 x, int256 y) internal pure returns (int256) {
+    unchecked {
+      if (x == MIN_64x64) {
+        require (y >= -0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF &&
+          y <= 0x1000000000000000000000000000000000000000000000000);
+        return -y << 63;
+      } else {
+        bool negativeResult = false;
+        if (x < 0) {
+          x = -x;
+          negativeResult = true;
+        }
+        if (y < 0) {
+          y = -y; // We rely on overflow behavior here
+          negativeResult = !negativeResult;
+        }
+        uint256 absoluteResult = mulu (x, uint256 (y));
+        if (negativeResult) {
+          require (absoluteResult <=
+            0x8000000000000000000000000000000000000000000000000000000000000000);
+          return -int256 (absoluteResult); // We rely on overflow behavior here
+        } else {
+          require (absoluteResult <=
+            0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+          return int256 (absoluteResult);
+        }
+      }
+    }
+  }
+
+  /**
+   * Calculate x * y rounding down, where x is signed 64.64 fixed point number
+   * and y is unsigned 256-bit integer number.  Revert on overflow.
+   *
+   * @param x signed 64.64 fixed point number
+   * @param y unsigned 256-bit integer number
+   * @return unsigned 256-bit integer number
+   */
+  function mulu (int128 x, uint256 y) internal pure returns (uint256) {
+    unchecked {
+      if (y == 0) return 0;
+
+      require (x >= 0);
+
+      uint256 lo = (uint256 (int256 (x)) * (y & 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)) >> 64;
+      uint256 hi = uint256 (int256 (x)) * (y >> 128);
+
+      require (hi <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+      hi <<= 64;
+
+      require (hi <=
+        0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF - lo);
+      return hi + lo;
+    }
+  }
+
+  /**
+   * Calculate x / y rounding towards zero.  Revert on overflow or when y is
+   * zero.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function div (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      require (y != 0);
+      int256 result = (int256 (x) << 64) / y;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate x / y rounding towards zero, where x and y are signed 256-bit
+   * integer numbers.  Revert on overflow or when y is zero.
+   *
+   * @param x signed 256-bit integer number
+   * @param y signed 256-bit integer number
+   * @return signed 64.64-bit fixed point number
+   */
+  function divi (int256 x, int256 y) internal pure returns (int128) {
+    unchecked {
+      require (y != 0);
+
+      bool negativeResult = false;
+      if (x < 0) {
+        x = -x; // We rely on overflow behavior here
+        negativeResult = true;
+      }
+      if (y < 0) {
+        y = -y; // We rely on overflow behavior here
+        negativeResult = !negativeResult;
+      }
+      uint128 absoluteResult = divuu (uint256 (x), uint256 (y));
+      if (negativeResult) {
+        require (absoluteResult <= 0x80000000000000000000000000000000);
+        return -int128 (absoluteResult); // We rely on overflow behavior here
+      } else {
+        require (absoluteResult <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+        return int128 (absoluteResult); // We rely on overflow behavior here
+      }
+    }
+  }
+
+  /**
+   * Calculate x / y rounding towards zero, where x and y are unsigned 256-bit
+   * integer numbers.  Revert on overflow or when y is zero.
+   *
+   * @param x unsigned 256-bit integer number
+   * @param y unsigned 256-bit integer number
+   * @return signed 64.64-bit fixed point number
+   */
+  function divu (uint256 x, uint256 y) internal pure returns (int128) {
+    unchecked {
+      require (y != 0);
+      uint128 result = divuu (x, y);
+      require (result <= uint128 (MAX_64x64));
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate -x.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function neg (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x != MIN_64x64);
+      return -x;
+    }
+  }
+
+  /**
+   * Calculate |x|.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function abs (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x != MIN_64x64);
+      return x < 0 ? -x : x;
+    }
+  }
+
+  /**
+   * Calculate 1 / x rounding towards zero.  Revert on overflow or when x is
+   * zero.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function inv (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x != 0);
+      int256 result = int256 (0x100000000000000000000000000000000) / x;
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate arithmetics average of x and y, i.e. (x + y) / 2 rounding down.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function avg (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      return int128 ((int256 (x) + int256 (y)) >> 1);
+    }
+  }
+
+  /**
+   * Calculate geometric average of x and y, i.e. sqrt (x * y) rounding down.
+   * Revert on overflow or in case x * y is negative.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function gavg (int128 x, int128 y) internal pure returns (int128) {
+    unchecked {
+      int256 m = int256 (x) * int256 (y);
+      require (m >= 0);
+      require (m <
+          0x4000000000000000000000000000000000000000000000000000000000000000);
+      return int128 (sqrtu (uint256 (m)));
+    }
+  }
+
+  /**
+   * Calculate x^y assuming 0^0 is 1, where x is signed 64.64 fixed point number
+   * and y is unsigned 256-bit integer number.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @param y uint256 value
+   * @return signed 64.64-bit fixed point number
+   */
+  function pow (int128 x, uint256 y) internal pure returns (int128) {
+    unchecked {
+      bool negative = x < 0 && y & 1 == 1;
+
+      uint256 absX = uint128 (x < 0 ? -x : x);
+      uint256 absResult;
+      absResult = 0x100000000000000000000000000000000;
+
+      if (absX <= 0x10000000000000000) {
+        absX <<= 63;
+        while (y != 0) {
+          if (y & 0x1 != 0) {
+            absResult = absResult * absX >> 127;
+          }
+          absX = absX * absX >> 127;
+
+          if (y & 0x2 != 0) {
+            absResult = absResult * absX >> 127;
+          }
+          absX = absX * absX >> 127;
+
+          if (y & 0x4 != 0) {
+            absResult = absResult * absX >> 127;
+          }
+          absX = absX * absX >> 127;
+
+          if (y & 0x8 != 0) {
+            absResult = absResult * absX >> 127;
+          }
+          absX = absX * absX >> 127;
+
+          y >>= 4;
+        }
+
+        absResult >>= 64;
+      } else {
+        uint256 absXShift = 63;
+        if (absX < 0x1000000000000000000000000) { absX <<= 32; absXShift -= 32; }
+        if (absX < 0x10000000000000000000000000000) { absX <<= 16; absXShift -= 16; }
+        if (absX < 0x1000000000000000000000000000000) { absX <<= 8; absXShift -= 8; }
+        if (absX < 0x10000000000000000000000000000000) { absX <<= 4; absXShift -= 4; }
+        if (absX < 0x40000000000000000000000000000000) { absX <<= 2; absXShift -= 2; }
+        if (absX < 0x80000000000000000000000000000000) { absX <<= 1; absXShift -= 1; }
+
+        uint256 resultShift = 0;
+        while (y != 0) {
+          require (absXShift < 64);
+
+          if (y & 0x1 != 0) {
+            absResult = absResult * absX >> 127;
+            resultShift += absXShift;
+            if (absResult > 0x100000000000000000000000000000000) {
+              absResult >>= 1;
+              resultShift += 1;
+            }
+          }
+          absX = absX * absX >> 127;
+          absXShift <<= 1;
+          if (absX >= 0x100000000000000000000000000000000) {
+              absX >>= 1;
+              absXShift += 1;
+          }
+
+          y >>= 1;
+        }
+
+        require (resultShift < 64);
+        absResult >>= 64 - resultShift;
+      }
+      int256 result = negative ? -int256 (absResult) : int256 (absResult);
+      require (result >= MIN_64x64 && result <= MAX_64x64);
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate sqrt (x) rounding down.  Revert if x < 0.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function sqrt (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x >= 0);
+      return int128 (sqrtu (uint256 (int256 (x)) << 64));
+    }
+  }
+
+  /**
+   * Calculate binary logarithm of x.  Revert if x <= 0.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function log_2 (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x > 0);
+
+      int256 msb = 0;
+      int256 xc = x;
+      if (xc >= 0x10000000000000000) { xc >>= 64; msb += 64; }
+      if (xc >= 0x100000000) { xc >>= 32; msb += 32; }
+      if (xc >= 0x10000) { xc >>= 16; msb += 16; }
+      if (xc >= 0x100) { xc >>= 8; msb += 8; }
+      if (xc >= 0x10) { xc >>= 4; msb += 4; }
+      if (xc >= 0x4) { xc >>= 2; msb += 2; }
+      if (xc >= 0x2) msb += 1;  // No need to shift xc anymore
+
+      int256 result = msb - 64 << 64;
+      uint256 ux = uint256 (int256 (x)) << uint256 (127 - msb);
+      for (int256 bit = 0x8000000000000000; bit > 0; bit >>= 1) {
+        ux *= ux;
+        uint256 b = ux >> 255;
+        ux >>= 127 + b;
+        result += bit * int256 (b);
+      }
+
+      return int128 (result);
+    }
+  }
+
+  /**
+   * Calculate natural logarithm of x.  Revert if x <= 0.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function ln (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x > 0);
+
+      return int128 (int256 (
+          uint256 (int256 (log_2 (x))) * 0xB17217F7D1CF79ABC9E3B39803F2F6AF >> 128));
+    }
+  }
+
+  /**
+   * Calculate binary exponent of x.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function exp_2 (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x < 0x400000000000000000); // Overflow
+
+      if (x < -0x400000000000000000) return 0; // Underflow
+
+      uint256 result = 0x80000000000000000000000000000000;
+
+      if (x & 0x8000000000000000 > 0)
+        result = result * 0x16A09E667F3BCC908B2FB1366EA957D3E >> 128;
+      if (x & 0x4000000000000000 > 0)
+        result = result * 0x1306FE0A31B7152DE8D5A46305C85EDEC >> 128;
+      if (x & 0x2000000000000000 > 0)
+        result = result * 0x1172B83C7D517ADCDF7C8C50EB14A791F >> 128;
+      if (x & 0x1000000000000000 > 0)
+        result = result * 0x10B5586CF9890F6298B92B71842A98363 >> 128;
+      if (x & 0x800000000000000 > 0)
+        result = result * 0x1059B0D31585743AE7C548EB68CA417FD >> 128;
+      if (x & 0x400000000000000 > 0)
+        result = result * 0x102C9A3E778060EE6F7CACA4F7A29BDE8 >> 128;
+      if (x & 0x200000000000000 > 0)
+        result = result * 0x10163DA9FB33356D84A66AE336DCDFA3F >> 128;
+      if (x & 0x100000000000000 > 0)
+        result = result * 0x100B1AFA5ABCBED6129AB13EC11DC9543 >> 128;
+      if (x & 0x80000000000000 > 0)
+        result = result * 0x10058C86DA1C09EA1FF19D294CF2F679B >> 128;
+      if (x & 0x40000000000000 > 0)
+        result = result * 0x1002C605E2E8CEC506D21BFC89A23A00F >> 128;
+      if (x & 0x20000000000000 > 0)
+        result = result * 0x100162F3904051FA128BCA9C55C31E5DF >> 128;
+      if (x & 0x10000000000000 > 0)
+        result = result * 0x1000B175EFFDC76BA38E31671CA939725 >> 128;
+      if (x & 0x8000000000000 > 0)
+        result = result * 0x100058BA01FB9F96D6CACD4B180917C3D >> 128;
+      if (x & 0x4000000000000 > 0)
+        result = result * 0x10002C5CC37DA9491D0985C348C68E7B3 >> 128;
+      if (x & 0x2000000000000 > 0)
+        result = result * 0x1000162E525EE054754457D5995292026 >> 128;
+      if (x & 0x1000000000000 > 0)
+        result = result * 0x10000B17255775C040618BF4A4ADE83FC >> 128;
+      if (x & 0x800000000000 > 0)
+        result = result * 0x1000058B91B5BC9AE2EED81E9B7D4CFAB >> 128;
+      if (x & 0x400000000000 > 0)
+        result = result * 0x100002C5C89D5EC6CA4D7C8ACC017B7C9 >> 128;
+      if (x & 0x200000000000 > 0)
+        result = result * 0x10000162E43F4F831060E02D839A9D16D >> 128;
+      if (x & 0x100000000000 > 0)
+        result = result * 0x100000B1721BCFC99D9F890EA06911763 >> 128;
+      if (x & 0x80000000000 > 0)
+        result = result * 0x10000058B90CF1E6D97F9CA14DBCC1628 >> 128;
+      if (x & 0x40000000000 > 0)
+        result = result * 0x1000002C5C863B73F016468F6BAC5CA2B >> 128;
+      if (x & 0x20000000000 > 0)
+        result = result * 0x100000162E430E5A18F6119E3C02282A5 >> 128;
+      if (x & 0x10000000000 > 0)
+        result = result * 0x1000000B1721835514B86E6D96EFD1BFE >> 128;
+      if (x & 0x8000000000 > 0)
+        result = result * 0x100000058B90C0B48C6BE5DF846C5B2EF >> 128;
+      if (x & 0x4000000000 > 0)
+        result = result * 0x10000002C5C8601CC6B9E94213C72737A >> 128;
+      if (x & 0x2000000000 > 0)
+        result = result * 0x1000000162E42FFF037DF38AA2B219F06 >> 128;
+      if (x & 0x1000000000 > 0)
+        result = result * 0x10000000B17217FBA9C739AA5819F44F9 >> 128;
+      if (x & 0x800000000 > 0)
+        result = result * 0x1000000058B90BFCDEE5ACD3C1CEDC823 >> 128;
+      if (x & 0x400000000 > 0)
+        result = result * 0x100000002C5C85FE31F35A6A30DA1BE50 >> 128;
+      if (x & 0x200000000 > 0)
+        result = result * 0x10000000162E42FF0999CE3541B9FFFCF >> 128;
+      if (x & 0x100000000 > 0)
+        result = result * 0x100000000B17217F80F4EF5AADDA45554 >> 128;
+      if (x & 0x80000000 > 0)
+        result = result * 0x10000000058B90BFBF8479BD5A81B51AD >> 128;
+      if (x & 0x40000000 > 0)
+        result = result * 0x1000000002C5C85FDF84BD62AE30A74CC >> 128;
+      if (x & 0x20000000 > 0)
+        result = result * 0x100000000162E42FEFB2FED257559BDAA >> 128;
+      if (x & 0x10000000 > 0)
+        result = result * 0x1000000000B17217F7D5A7716BBA4A9AE >> 128;
+      if (x & 0x8000000 > 0)
+        result = result * 0x100000000058B90BFBE9DDBAC5E109CCE >> 128;
+      if (x & 0x4000000 > 0)
+        result = result * 0x10000000002C5C85FDF4B15DE6F17EB0D >> 128;
+      if (x & 0x2000000 > 0)
+        result = result * 0x1000000000162E42FEFA494F1478FDE05 >> 128;
+      if (x & 0x1000000 > 0)
+        result = result * 0x10000000000B17217F7D20CF927C8E94C >> 128;
+      if (x & 0x800000 > 0)
+        result = result * 0x1000000000058B90BFBE8F71CB4E4B33D >> 128;
+      if (x & 0x400000 > 0)
+        result = result * 0x100000000002C5C85FDF477B662B26945 >> 128;
+      if (x & 0x200000 > 0)
+        result = result * 0x10000000000162E42FEFA3AE53369388C >> 128;
+      if (x & 0x100000 > 0)
+        result = result * 0x100000000000B17217F7D1D351A389D40 >> 128;
+      if (x & 0x80000 > 0)
+        result = result * 0x10000000000058B90BFBE8E8B2D3D4EDE >> 128;
+      if (x & 0x40000 > 0)
+        result = result * 0x1000000000002C5C85FDF4741BEA6E77E >> 128;
+      if (x & 0x20000 > 0)
+        result = result * 0x100000000000162E42FEFA39FE95583C2 >> 128;
+      if (x & 0x10000 > 0)
+        result = result * 0x1000000000000B17217F7D1CFB72B45E1 >> 128;
+      if (x & 0x8000 > 0)
+        result = result * 0x100000000000058B90BFBE8E7CC35C3F0 >> 128;
+      if (x & 0x4000 > 0)
+        result = result * 0x10000000000002C5C85FDF473E242EA38 >> 128;
+      if (x & 0x2000 > 0)
+        result = result * 0x1000000000000162E42FEFA39F02B772C >> 128;
+      if (x & 0x1000 > 0)
+        result = result * 0x10000000000000B17217F7D1CF7D83C1A >> 128;
+      if (x & 0x800 > 0)
+        result = result * 0x1000000000000058B90BFBE8E7BDCBE2E >> 128;
+      if (x & 0x400 > 0)
+        result = result * 0x100000000000002C5C85FDF473DEA871F >> 128;
+      if (x & 0x200 > 0)
+        result = result * 0x10000000000000162E42FEFA39EF44D91 >> 128;
+      if (x & 0x100 > 0)
+        result = result * 0x100000000000000B17217F7D1CF79E949 >> 128;
+      if (x & 0x80 > 0)
+        result = result * 0x10000000000000058B90BFBE8E7BCE544 >> 128;
+      if (x & 0x40 > 0)
+        result = result * 0x1000000000000002C5C85FDF473DE6ECA >> 128;
+      if (x & 0x20 > 0)
+        result = result * 0x100000000000000162E42FEFA39EF366F >> 128;
+      if (x & 0x10 > 0)
+        result = result * 0x1000000000000000B17217F7D1CF79AFA >> 128;
+      if (x & 0x8 > 0)
+        result = result * 0x100000000000000058B90BFBE8E7BCD6D >> 128;
+      if (x & 0x4 > 0)
+        result = result * 0x10000000000000002C5C85FDF473DE6B2 >> 128;
+      if (x & 0x2 > 0)
+        result = result * 0x1000000000000000162E42FEFA39EF358 >> 128;
+      if (x & 0x1 > 0)
+        result = result * 0x10000000000000000B17217F7D1CF79AB >> 128;
+
+      result >>= uint256 (int256 (63 - (x >> 64)));
+      require (result <= uint256 (int256 (MAX_64x64)));
+
+      return int128 (int256 (result));
+    }
+  }
+
+  /**
+   * Calculate natural exponent of x.  Revert on overflow.
+   *
+   * @param x signed 64.64-bit fixed point number
+   * @return signed 64.64-bit fixed point number
+   */
+  function exp (int128 x) internal pure returns (int128) {
+    unchecked {
+      require (x < 0x400000000000000000); // Overflow
+
+      if (x < -0x400000000000000000) return 0; // Underflow
+
+      return exp_2 (
+          int128 (int256 (x) * 0x171547652B82FE1777D0FFDA0D23A7D12 >> 128));
+    }
+  }
+
+  /**
+   * Calculate x / y rounding towards zero, where x and y are unsigned 256-bit
+   * integer numbers.  Revert on overflow or when y is zero.
+   *
+   * @param x unsigned 256-bit integer number
+   * @param y unsigned 256-bit integer number
+   * @return unsigned 64.64-bit fixed point number
+   */
+  function divuu (uint256 x, uint256 y) private pure returns (uint128) {
+    unchecked {
+      require (y != 0);
+
+      uint256 result;
+
+      if (x <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
+        result = (x << 64) / y;
+      else {
+        uint256 msb = 192;
+        uint256 xc = x >> 192;
+        if (xc >= 0x100000000) { xc >>= 32; msb += 32; }
+        if (xc >= 0x10000) { xc >>= 16; msb += 16; }
+        if (xc >= 0x100) { xc >>= 8; msb += 8; }
+        if (xc >= 0x10) { xc >>= 4; msb += 4; }
+        if (xc >= 0x4) { xc >>= 2; msb += 2; }
+        if (xc >= 0x2) msb += 1;  // No need to shift xc anymore
+
+        result = (x << 255 - msb) / ((y - 1 >> msb - 191) + 1);
+        require (result <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+
+        uint256 hi = result * (y >> 128);
+        uint256 lo = result * (y & 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+
+        uint256 xh = x >> 192;
+        uint256 xl = x << 64;
+
+        if (xl < lo) xh -= 1;
+        xl -= lo; // We rely on overflow behavior here
+        lo = hi << 128;
+        if (xl < lo) xh -= 1;
+        xl -= lo; // We rely on overflow behavior here
+
+        assert (xh == hi >> 128);
+
+        result += xl / y;
+      }
+
+      require (result <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+      return uint128 (result);
+    }
+  }
+
+  /**
+   * Calculate sqrt (x) rounding down, where x is unsigned 256-bit integer
+   * number.
+   *
+   * @param x unsigned 256-bit integer number
+   * @return unsigned 128-bit integer number
+   */
+  function sqrtu (uint256 x) private pure returns (uint128) {
+    unchecked {
+      if (x == 0) return 0;
+      else {
+        uint256 xx = x;
+        uint256 r = 1;
+        if (xx >= 0x100000000000000000000000000000000) { xx >>= 128; r <<= 64; }
+        if (xx >= 0x10000000000000000) { xx >>= 64; r <<= 32; }
+        if (xx >= 0x100000000) { xx >>= 32; r <<= 16; }
+        if (xx >= 0x10000) { xx >>= 16; r <<= 8; }
+        if (xx >= 0x100) { xx >>= 8; r <<= 4; }
+        if (xx >= 0x10) { xx >>= 4; r <<= 2; }
+        if (xx >= 0x4) { r <<= 1; }
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1;
+        r = (r + x / r) >> 1; // Seven iterations should be enough
+        uint256 r1 = x / r;
+        return uint128 (r < r1 ? r : r1);
+      }
+    }
+  }
+}

solidity/aux/LICENSE.md

@@ -0,0 +1,28 @@
+Copyright (c) 2019, [ABDK Consulting](https://abdk.consulting/)
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+3. All advertising materials mentioning features or use of this software must
+   display the following acknowledgement: This product includes software
+   developed by ABDK Consulting.
+4. Neither the name of ABDK Consulting nor the names of its contributors may be
+   used to endorse or promote products derived from this software without
+   specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY ABDK CONSULTING ''AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+SHALL ABDK CONSULTING BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+OF SUCH DAMAGE.