Move bitfields to struct

Runaway redistribution

See merge request cicnet/erc20-demurrage-token!10

CAVEAT

@@ -0,0 +1,5 @@
+The contract is intended for slow rates of decay (e.g. 2% per month). Very high levels of decay (2% per minute) will lead to overflows, and will need a more flexible implementation to support it.
+
+The contract is written with frequent usage in mind. If used for tokens with low usage freqency (e.g. several days idle), it is recommended to run a continuous process triggering the changePeriod() contract call, to reduce the amount of exponential calculation the application of demurrage will trigger.
+
+When changing the period, 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. 

ROADMAP

@@ -0,0 +1,8 @@
+- 0.1.3
+	* Snapshot supply for crossed redistribution thresholds before minting new tokens.
+- 0.1.4
+	* Implement natural logarithm 
+- 0.1.5
+	* Port changes from SingleNocap to SingleCap
+- 0.2.0
+	* Make decay resolutions configurable, to support high levels of decay.

VERSION

@@ -0,0 +1 @@
+0.1.2

python/CHANGELOG

@@ -1,3 +1,9 @@
+- 0.2.0
+	* Add token burn function
+	* Fix gas leak when calculating decay on period change
+	* Remove all but SingleNocap contract in make install
+	* Make approve explicitly set value
+	* Add increaseAllowance and decreaseAllowance methods
 - 0.1.1
 	* Settable demurrage steps for apply demurrage cli tool
 - 0.1.0

python/erc20_demurrage_token/runnable/apply.py

@@ -16,17 +16,7 @@ import math
 
 # 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,
-        OverrideNonceOracle,
-        )
-from chainlib.eth.gas import (
-        RPCGasOracle,
-        OverrideGasOracle,
-        )
+import chainlib.eth.cli
 from chainlib.eth.block import (
         block_latest,
         block_by_number,
@@ -35,8 +25,20 @@ from chainlib.eth.block 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 hexathon import to_int as hex_to_int
+import chainlib.eth.cli
+from chainlib.eth.settings import process_settings
+from chainlib.settings import ChainSettings
+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
 
 # local imports
 import erc20_demurrage_token
@@ -45,32 +47,38 @@ from erc20_demurrage_token import (
         DemurrageTokenSettings,
         )
 
-logging.basicConfig(level=logging.WARNING)
 logg = logging.getLogger()
 
-script_dir = os.path.dirname(__file__)
-data_dir = os.path.join(script_dir, '..', 'data')
 
-config_dir = os.path.join(data_dir, 'config')
+def process_config_local(config, arg, args, flags):
+    config.add(args.steps, '_STEPS', False)
+    return config
 
-arg_flags = chainlib.eth.cli.argflag_std_write | chainlib.eth.cli.Flag.EXEC
-argparser = chainlib.eth.cli.ArgumentParser(arg_flags)
+
+arg_flags = ArgFlag()
+arg = Arg(arg_flags)
+flags = arg_flags.STD_WRITE | arg_flags.EXEC | arg_flags.WALLET
+
+argparser = chainlib.eth.cli.ArgumentParser()
+argparser = process_args(argparser, arg, flags)
 argparser.add_argument('--steps', type=int, default=0, help='Max demurrage steps to apply per round')
 args = argparser.parse_args()
-config = chainlib.eth.cli.Config.from_args(args, arg_flags, default_fee_limit=DemurrageToken.gas(), base_config_dir=config_dir)
-config.add(args.steps, '_STEPS', False)
+
+logg = process_log(args, logg)
+
+config = Config()
+config = process_config(config, arg, args, flags)
+config = process_config_local(config, arg, args, flags)
 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'))
+settings = ChainSettings()
+settings = process_settings(settings, config)
+logg.debug('settings loaded:\n{}'.format(settings))
 
 
 def main():
+    chain_spec = settings.get('CHAIN_SPEC')
+    conn = settings.get('CONN')
     o = block_latest()
     r = conn.do(o)
  
@@ -87,9 +95,9 @@ def main():
     block_start_timestamp = block_start.timestamp
     block_start_datetime = datetime.datetime.fromtimestamp(block_start_timestamp)
 
-    gas_oracle = rpc.get_gas_oracle()
+    gas_oracle = settings.get('FEE_ORACLE')
     c = DemurrageToken(chain_spec, gas_oracle=gas_oracle)
-    o = c.demurrage_timestamp(config.get('_EXEC_ADDRESS'))
+    o = c.demurrage_timestamp(settings.get('EXEC'))
     r = conn.do(o)
 
     demurrage_timestamp = None
@@ -120,17 +128,17 @@ def main():
 
     last_tx_hash = None
     for i in range(rounds):
-        signer = rpc.get_signer()
-        signer_address = rpc.get_sender_address()
+        signer = settings.get('SIGNER')
+        signer_address = settings.get('SENDER_ADDRESS')
 
-        nonce_oracle = rpc.get_nonce_oracle()
+        nonce_oracle = settings.get('NONCE_ORACLE')
 
         c = DemurrageToken(chain_spec, signer=signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
         (tx_hash_hex, o) = c.apply_demurrage(config.get('_EXEC_ADDRESS'), signer_address, limit=config.get('_STEPS'))
-        if config.get('_RPC_SEND'):
+        if settings.get('RPC_SEND'):
             print(tx_hash_hex)
             conn.do(o)
-            if config.get('_WAIT_ALL') or (i == rounds - 1 and config.get('_WAIT')):
+            if config.true('_WAIT_ALL') or (i == rounds - 1 and 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')

python/erc20_demurrage_token/runnable/deploy.py

@@ -14,21 +14,22 @@ import logging
 
 # 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,
-        OverrideNonceOracle,
-        )
-from chainlib.eth.gas import (
-        RPCGasOracle,
-        OverrideGasOracle,
-        )
 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.settings import process_settings
+from chainlib.settings import ChainSettings
+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
 
 # local imports
 import erc20_demurrage_token
@@ -37,84 +38,75 @@ from erc20_demurrage_token import (
         DemurrageTokenSettings,
         )
 
-logging.basicConfig(level=logging.WARNING)
 logg = logging.getLogger()
 
-script_dir = os.path.dirname(__file__)
-data_dir = os.path.join(script_dir, '..', 'data')
 
-config_dir = os.path.join(data_dir, 'config')
+def process_config_local(config, arg, args, flags):
+    config.add(args.token_name, 'TOKEN_NAME', False)
+    config.add(args.token_symbol, 'TOKEN_SYMBOL', False)
+    config.add(args.token_decimals, 'TOKEN_DECIMALS', False)
+    config.add(args.sink_address, 'TOKEN_SINK_ADDRESS', False)
+    config.add(args.redistribution_period, 'TOKEN_REDISTRIBUTION_PERIOD', False)
+    config.add(args.demurrage_level, 'TOKEN_DEMURRAGE_LEVEL', False)
+    config.add(0, 'TOKEN_SUPPLY_LIMIT', False)
+    return config
 
-arg_flags = chainlib.eth.cli.argflag_std_write
-argparser = chainlib.eth.cli.ArgumentParser(arg_flags)
+
+arg_flags = ArgFlag()
+arg = Arg(arg_flags)
+flags = arg_flags.STD_WRITE | arg_flags.EXEC | arg_flags.WALLET
+
+argparser = chainlib.eth.cli.ArgumentParser()
+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('--supply-limit', dest='supply_limit', type=int, help='token supply limit (0 = no limit)')
-argparser.add_argument('--redistribution-period', type=int, help='redistribution period, minutes (0 = deactivate)') # default 10080 = week
-argparser.add_argument('--multi', action='store_true', help='automatic redistribution')
+#argparser.add_argument('--supply-limit', dest='supply_limit', type=int, help='token supply limit (0 = no limit)')
+argparser.add_argument('--redistribution-period', dest='redistribution_period', type=int, help='redistribution period, minutes (0 = deactivate)') # default 10080 = week
+#argparser.add_argument('--multi', action='store_true', help='automatic redistribution')
 argparser.add_argument('--demurrage-level', dest='demurrage_level', type=int, help='demurrage level, ppm per minute') 
 args = argparser.parse_args()
 
-arg_flags = chainlib.eth.cli.argflag_std_write
+logg = process_log(args, logg)
 
-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)
+config = Config()
+config = process_config(config, arg, args, flags)
+config = process_config_local(config, arg, args, flags)
 logg.debug('config loaded:\n{}'.format(config))
 
-wallet = chainlib.eth.cli.Wallet()
-wallet.from_config(config)
+settings = ChainSettings()
+settings = process_settings(settings, config)
+logg.debug('settings loaded:\n{}'.format(settings))
 
-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():
-    signer = rpc.get_signer()
-    signer_address = rpc.get_sender_address()
+    chain_spec = settings.get('CHAIN_SPEC')
+    conn = settings.get('CONN')
+    signer = settings.get('SIGNER')
+    signer_address = settings.get('SENDER_ADDRESS')
 
-    gas_oracle = rpc.get_gas_oracle()
-    nonce_oracle = rpc.get_nonce_oracle()
+    gas_oracle = settings.get('FEE_ORACLE')
+    nonce_oracle = settings.get('NONCE_ORACLE')
 
     c = DemurrageToken(chain_spec, signer=signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
-    settings = DemurrageTokenSettings()
-    settings.name = config.get('TOKEN_NAME')
-    settings.symbol = config.get('TOKEN_SYMBOL')
-    settings.decimals = int(config.get('TOKEN_DECIMALS'))
-    settings.demurrage_level = int(config.get('TOKEN_DEMURRAGE_LEVEL'))
-    settings.period_minutes = int(config.get('TOKEN_REDISTRIBUTION_PERIOD'))
-    settings.sink_address = config.get('TOKEN_SINK_ADDRESS')
+    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(
             signer_address,
-            settings,
+            token_settings,
             redistribute=config.true('_MULTI'),
             cap=int(config.get('TOKEN_SUPPLY_LIMIT')),
             )
-    if config.get('_RPC_SEND'):
+    if settings.get('RPC_SEND'):
         conn.do(o)
-        if config.get('_WAIT'):
+        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')

python/erc20_demurrage_token/token.py

@@ -10,7 +10,6 @@ from chainlib.eth.tx import (
 from chainlib.hash import keccak256_string_to_hex
 from chainlib.eth.contract import (
         ABIContractEncoder,
-        ABIContractDecoder,
         ABIContractType,
         abi_decode_single,
         )
@@ -576,16 +575,7 @@ class DemurrageToken(ERC20):
     
     @classmethod
     def parse_redistributions(self, v):
-        d = ABIContractDecoder()
-        v = strip_0x(v)
-        d.typ(ABIContractType.BYTES32)
-        d.typ(ABIContractType.BYTES32)
-        d.typ(ABIContractType.BYTES32)
-        d.val(v[:64])
-        d.val(v[64:128])
-        d.val(v[128:192])
-        r = d.decode()
-        return ''.join(r)
+        return abi_decode_single(ABIContractType.BYTES32, v)
 
 
     @classmethod

python/erc20_demurrage_token/unittest/base.py

@@ -20,7 +20,7 @@ from erc20_demurrage_token import (
         DemurrageToken,
         )
 
-logg = logging.getLogger()
+logg = logging.getLogger(__name__)
 
 #BLOCKTIME = 5 # seconds
 TAX_LEVEL = int(10000 * 2) # 2%
@@ -95,13 +95,6 @@ class TestDemurrage(EthTesterCase):
 
     def setUp(self):
         super(TestDemurrage, self).setUp()
-#        token_deploy = TestTokenDeploy()
-#        self.settings = token_deploy.settings
-#        self.sink_address = token_deploy.sink_address
-#        self.start_block = token_deploy.start_block
-#        self.start_time = token_deploy.start_time
-#        self.default_supply = self.default_supply
-#        self.default_supply_cap = self.default_supply_cap
         period = PERIOD
         try:
             period = getattr(self, 'period')
@@ -133,6 +126,13 @@ class TestDemurrage(EthTesterCase):
         logg.debug('asserted within lower {} <= {} <= {}'.format(lower_target, v, target))
 
 
+    def assert_within_greater(self, v, target, tolerance_ppm):
+        higher_target = target + (target * (tolerance_ppm / 1000000))
+        self.assertLessEqual(v, higher_target)
+        self.assertGreaterEqual(v, target)
+        logg.debug('asserted within lower {} <= {} <= {}'.format(target, v, higher_target))
+
+
     def tearDown(self):
         pass
 

python/requirements.txt

@@ -1,3 +1,3 @@
-chainlib-eth>=0.1.0,<0.2.0
-eth-erc20~=0.3.0
+chainlib-eth~=0.4.11
+eth-erc20~=0.5.1
 funga-eth~=0.6.0

python/run_tests.sh

@@ -13,6 +13,7 @@ for m in ${modes[@]}; do
 	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_growth.py
 	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_amounts.py
 	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_single.py
+	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_burn.py
 done
 
 #modes=(SingleCap) # other contracts need to be updted

python/setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = erc20-demurrage-token
-version = 0.1.1
+version = 0.2.0
 description = ERC20 token with redistributed continual demurrage
 author = Louis Holbrook
 author_email = dev@holbrook.no

python/tests/test_burn.py

@@ -0,0 +1,320 @@
+# 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.base import TestDemurrage
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+TAX_LEVEL = 2
+
+class TestBurn(TestDemurrage):
+
+    def setUp(self):
+        super(TestBurn, self).setUp()
+
+
+    def deploy(self, tax_level=None):
+        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))
+
+        if tax_level != None:
+            self.deployer.settings.demurrage_level = tax_level * (10 ** 32)
+        self.deployer.settings.sink_address = self.accounts[9]
+        self.deployer.sink_address = self.accounts[9]
+        super(TestBurn, self).deploy(c, self.mode)
+
+        logg.info('deployed with mode {}'.format(self.mode))
+
+
+    # Burn tokens and immediately check balances and supply
+    def test_burn_basic(self):
+        self.deploy()
+        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], 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.burn(self.address, self.accounts[1], 600000)
+        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 = 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)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.burn(self.address, self.accounts[1], 600000)
+        r = 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)
+        new_supply = c.parse_total_supply(r)
+        self.assertEqual(new_supply, 400000)
+
+        o = c.total_burned(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        burned = c.parse_total_burned(r)
+        self.assertEqual(burned, 600000)
+
+
+    # burn tokens and check sink balance and supply after first redistribution period
+    def test_burned_redistribution(self):
+        self.deploy()
+        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], 1000000000)
+        r = self.rpc.do(o)
+
+        (tx_hash, o) = c.burn(self.address, self.accounts[0], 500000000)
+        r = self.rpc.do(o)
+
+        (tx_hash, o) = c.transfer(self.address, self.accounts[0], self.sink_address, 500000000)
+        r = self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bal = c.parse_balance(r)
+        self.assertEqual(bal, 416873881) # 9 periods demurrage
+
+        (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.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        new_supply = c.parse_total_supply(r)
+        self.assertEqual(new_supply, 500000000)
+
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bal = c.parse_balance(r)
+        self.assert_within_lower(bal, 500000000, 0.0025)
+
+        self.backend.time_travel(self.start_time + (self.period_seconds * 2))
+
+        (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.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        new_supply = c.parse_total_supply(r)
+        self.assertEqual(new_supply, 500000000)
+
+        # if we don't burn anything more it should be the same 
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bal = c.parse_balance(r)
+        self.assert_within_lower(bal, 500000000, 0.0025)
+
+
+    # burn tokens and check sink and taxed balance and supply after first redistribution period
+    def test_burned_other_redistribution(self):
+        self.deploy()
+        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], 1000000000)
+        r = self.rpc.do(o)
+
+        (tx_hash, o) = c.burn(self.address, self.accounts[0], 500000000)
+        r = self.rpc.do(o)
+
+        (tx_hash, o) = c.transfer(self.address, self.accounts[0], self.accounts[1], 500000000)
+        r = self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + self.period_seconds)
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bal = c.parse_balance(r)
+        self.assertEqual(bal, 416873881) # 9 periods demurrage
+
+        (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.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        new_supply = c.parse_total_supply(r)
+        self.assertEqual(new_supply, 500000000)
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bal = c.parse_balance(r)
+        self.assertEqual(bal, 408536403) # 9 periods demurrage
+
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        sink_bal = c.parse_balance(r)
+        self.assert_within_lower(sink_bal, 500000000 - 408536403, 0.09) # TODO is this ok variance, 1.0 is ppm?
+
+        self.backend.time_travel(self.start_time + (self.period_seconds * 2))
+
+        (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.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        new_supply = c.parse_total_supply(r)
+        self.assertEqual(new_supply, 500000000)
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        next_bal = c.parse_balance(r)
+        self.assertEqual(next_bal, 333803985) # 9 periods demurrage
+
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        prev_sink_bal = sink_bal
+        bal = prev_sink_bal + (bal - next_bal)
+        sink_bal = c.parse_balance(r)
+        self.assert_within_lower(sink_bal, bal, 0.09) # TODO is this ok variance, 1.0 is ppm?
+
+
+    # verify expected results of balance and supply after multiple redistribution periods
+    def test_burn_accumulate(self):
+        self.deploy(tax_level=2/1000)
+        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.sink_address)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.sink_address, self.default_supply)
+        r = self.rpc.do(o)
+
+        balance_share = int(self.default_supply / 2)
+        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[1], balance_share)
+        r = self.rpc.do(o)
+
+        new_supply = None
+        burn_rate = 1000
+        sink_bal = None
+        bob_bal = None
+        bob_refund = None
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bob_bal = c.parse_balance(r)
+        prev_bob_bal = bob_bal
+
+        iterations = 100
+
+        for i in range(1, iterations + 1):
+            nonce_oracle = RPCNonceOracle(self.sink_address, self.rpc)
+            c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+            if bob_refund != None:
+                (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[1], bob_refund)
+                r = self.rpc.do(o)
+                o = receipt(tx_hash)
+                r = self.rpc.do(o)
+                self.assertEqual(r['status'], 1)
+
+            (tx_hash, o) = c.burn(self.address, self.sink_address, burn_rate)
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+            c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+            o = c.total_supply(self.address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            new_supply = c.parse_total_supply(r)
+
+            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 = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            bob_bal = c.parse_balance(r)
+            bob_refund = prev_bob_bal - bob_bal
+
+            o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            burner_bal = c.parse_balance(r)
+
+            sum_supply = bob_bal + burner_bal
+          
+            o = c.total_burned(self.address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            total_burned = c.parse_balance(r)
+
+            o = c.to_base_amount(self.address, total_burned, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            total_burned_base = c.parse_balance(r)
+
+            expected_supply = self.default_supply - (burn_rate * i)
+            logg.info('checking burn round {} balance burner {} bob {} supply {} expected {} summed {} burned {} base {}'.format(i, burner_bal, bob_bal, new_supply, expected_supply, sum_supply, total_burned, total_burned_base))
+            self.assertEqual(new_supply, expected_supply)
+
+        sum_supply = burner_bal + bob_bal
+        logg.debug('balances sink {} bob {} total {} supply real {} original {}'.format(sink_bal, bob_bal, sum_supply, new_supply, self.default_supply))
+
+        self.assert_within_lower(sum_supply, new_supply, 0.00001)
+        self.assert_within_greater(burner_bal, balance_share - total_burned, 0.1)
+
+        bob_delta = self.default_supply * ((2 / 1000000) / 1000)
+        self.assert_within_lower(bob_bal, balance_share - bob_delta, 0.1)
+        
+        self.assertEqual(total_burned, iterations * burn_rate)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/tests/test_demurrage.py

@@ -0,0 +1,133 @@
+# standard imports
+import datetime
+import unittest
+import logging
+import os
+
+# external imports
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token.demurrage import DemurrageCalculator
+
+# test imports
+from erc20_demurrage_token.unittest.base import TestDemurrage
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+
+class TestDemurragePeriods(TestDemurrage):
+
+    def setUp(self):
+        super(TestDemurragePeriods, 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.deployer.settings.demurrage_level = (2 / 1000) * (10 ** 32)
+        self.deployer.settings.sink_address = self.accounts[9]
+        self.deployer.sink_address = self.accounts[9]
+        self.deploy(c, self.mode)
+
+        logg.info('deployed with mode {}'.format(self.mode))
+
+
+    # verify that tax level calculation is in ppm as expected
+    def test_ppm(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)
+        r = self.rpc.do(o)
+
+        self.backend.time_travel(self.start_time + 60)
+
+        (tx_hash, o) = c.apply_demurrage(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(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bob_bal = c.parse_balance(r)
+
+        o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        sink_bal = c.parse_balance(r)
+
+        o = c.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        new_supply = c.parse_total_supply(r)
+
+        balance_delta = self.default_supply * ((2 / 1000000) / 1000) 
+        self.assertEqual(bob_bal, self.default_supply - balance_delta)
+
+
+
+    # verify balances and supply after multiple demurrage periods
+    def test_over_time(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)
+        r = self.rpc.do(o)
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bob_bal = c.parse_balance(r)
+        prev_bob_bal = bob_bal
+
+        nonce_oracle = RPCNonceOracle(self.sink_address, self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        iterations = 100
+
+        for i in range(1, iterations + 1):
+            self.backend.time_travel(self.start_time + (self.period_seconds * i))
+
+            (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[1], prev_bob_bal - bob_bal)
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            (tx_hash, o) = c.apply_demurrage(self.address, self.sink_address)
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            bob_bal = c.parse_balance(r)
+
+            o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            sink_bal = c.parse_balance(r)
+
+            o = c.total_supply(self.address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            new_supply = c.parse_total_supply(r)
+
+            logg.info('round {} supply {} balance sink {} bob {}'.format(i, new_supply, sink_bal, bob_bal))
+
+        sum_supply = sink_bal + bob_bal
+
+        bob_delta = self.default_supply * ((2 / 1000000) / 100)
+
+        self.assert_within_lower(sum_supply, new_supply, 0.00001)
+        self.assert_within_greater(bob_bal, self.default_supply - bob_delta, 0.001)
+        self.assert_within_lower(sink_bal, bob_delta, 1000)
+        
+
+if __name__ == '__main__':
+    unittest.main()

solidity/DemurrageTokenSingleNocap.sol

@@ -10,6 +10,15 @@ contract DemurrageTokenSingleCap {
 		uint104 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; // uint51(unused) | uint64(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 shiftRedistributionDemurrage	= 104;
+//	uint256 constant maskRedistributionDemurrage	= 0x0000000000ffffffffffffffffffffffffffff00000000000000000000000000; // ((1 << 36) - 1) << 140
 
 	// Account balances
 	mapping (address => uint256) account;
@@ -220,6 +229,16 @@ contract DemurrageTokenSingleCap {
 	}
 
 	// Deserializes the redistribution word
+	// uint95(unused) | uint20(demurrageModifier) | uint36(participants) | uint72(value) | uint32(period)
+//	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) public pure returns(bytes32) {
+//		bytes32 redistribution;
+//
+//		redistribution |= bytes32((_demurrageModifierPpm << shiftRedistributionDemurrage) & maskRedistributionDemurrage);
+//		redistribution |= bytes32((_value << shiftRedistributionValue) & maskRedistributionValue); 
+//		redistribution |= bytes32(_period & maskRedistributionPeriod);
+//		return redistribution;
+//	}
+
 	function toRedistribution(uint256 _participants, uint256 _demurrageModifierPpm, uint256 _value, uint256 _period) public pure returns(redistributionItem memory) {
 		redistributionItem memory redistribution;
 
@@ -229,18 +248,32 @@ contract DemurrageTokenSingleCap {
 		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 demurrage period part of the redistribution word
 	function toRedistributionPeriod(redistributionItem memory _redistribution) public pure returns (uint256) {
 		return uint256(_redistribution.period);
 	}
 
-	// Serializes the supply part of the redistribution word
+//	// Serializes the supply part of the redistribution word
+//	function toRedistributionSupply(bytes32 redistribution) public pure returns (uint256) {
+//		return (uint256(redistribution) & kkRedistributionValue) >> shiftRedistributionValue;
+//	}
+	
 	function toRedistributionSupply(redistributionItem memory _redistribution) public pure returns (uint256) {
 		return uint256(_redistribution.value);
 	}
 
-	// Serializes the number of participants part of the redistribution word
+//
+//	// Serializes the number of participants part of the redistribution word
+//	function toRedistributionDemurrageModifier(bytes32 redistribution) public pure returns (uint256) {
+//		return (uint256(redistribution) & maskRedistributionDemurrage) >> shiftRedistributionDemurrage;
+//	}
+
 	function toRedistributionDemurrageModifier(redistributionItem memory _redistribution) public pure returns (uint256) {
 		return uint256(_redistribution.demurrage);
 	}
@@ -250,8 +283,20 @@ contract DemurrageTokenSingleCap {
 	function redistributionCount() public view returns (uint256) {
 		return redistributions.length;
 	}
-
-	// Save the current total supply amount to the current redistribution period
+//
+//	// Save the current total supply amount to the current redistribution period
+//	function saveRedistributionSupply() private returns (bool) {
+//		uint256 currentRedistribution;
+//		uint256 grownSupply;
+//
+//		grownSupply = totalSupply();
+//		currentRedistribution = uint256(redistributions[redistributions.length-1]);
+//		currentRedistribution &= (~maskRedistributionValue);
+//		currentRedistribution |= (grownSupply << shiftRedistributionValue);
+//
+//		redistributions[redistributions.length-1] = bytes32(currentRedistribution);
+//		return true;
+//	}
 	function saveRedistributionSupply() private returns (bool) {
 		redistributionItem memory currentRedistribution;
 		uint256 grownSupply;

solidity/Makefile

@@ -1,6 +1,6 @@
 SOLC = /usr/bin/solc
 
-all: single_nocap
+all: multi single
 
 multi_nocap:
 	$(SOLC) DemurrageTokenMultiNocap.sol --abi --evm-version byzantium | awk 'NR>3' > DemurrageTokenMultiNocap.json
@@ -32,8 +32,15 @@ test: all
 	python ../python/tests/test_redistribution.py
 	python ../python/tests/test_pure.py
 
-install: all
-	cp -v DemurrageToken*.json ../python/erc20_demurrage_token/data/
-	cp -v DemurrageToken*.bin ../python/erc20_demurrage_token/data/
+#install: all
+install: single_nocap
+	#cp -v DemurrageToken*.{json,bin} ../python/erc20_demurrage_token/data/
+	cp -v DemurrageTokenSingleNocap.json ../python/erc20_demurrage_token/data/
+	cp -v DemurrageTokenSingleNocap.bin ../python/erc20_demurrage_token/data/
+
+install-broken: all
+	cp -v DemurrageToken*.{json,bin} ../python/erc20_demurrage_token/data/
+
+
 	
 .PHONY: test install