Merge branch 'dev-0.2.0' into 'master'

Runaway redistribution

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

python/CHANGELOG

@@ -1,7 +1,14 @@
+- 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
-	* Fix wrong redistribution calculation in single nocap
+	* Correct redistribution amount for SingleNocap contract
-[...]
 - 0.0.2
 	* Move to chainlib-eth
-- 0.0.1-unreleased
+- 0.0.1
 	* Interface for redistributed and non-redistributed, with or without cap

python/erc20_demurrage_token/runnable/apply.py

@@ -0,0 +1,144 @@
+"""Deploy sarafu token
+
+.. moduleauthor:: Louis Holbrook <dev@holbrook.no>
+.. pgp:: 0826EDA1702D1E87C6E2875121D2E7BB88C2A746 
+
+"""
+
+# standard imports
+import sys
+import os
+import json
+import argparse
+import logging
+import datetime
+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,
+        )
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+        Block,
+        )
+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
+
+# local imports
+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')
+
+config_dir = os.path.join(data_dir, 'config')
+
+arg_flags = chainlib.eth.cli.argflag_std_write | chainlib.eth.cli.Flag.EXEC
+argparser = chainlib.eth.cli.ArgumentParser(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.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():
+    o = block_latest()
+    r = conn.do(o)
+ 
+    block_start_number = None
+    try:
+        block_start_number = hex_to_int(r)
+    except TypeError:
+        block_start_number = int(r)
+
+    o = block_by_number(block_start_number)
+    r = conn.do(o)
+
+    block_start = Block(r)
+    block_start_timestamp = block_start.timestamp
+    block_start_datetime = datetime.datetime.fromtimestamp(block_start_timestamp)
+
+    gas_oracle = rpc.get_gas_oracle()
+    c = DemurrageToken(chain_spec, gas_oracle=gas_oracle)
+    o = c.demurrage_timestamp(config.get('_EXEC_ADDRESS'))
+    r = conn.do(o)
+
+    demurrage_timestamp = None
+    try:
+        demurrage_timestamp = hex_to_int(r)
+    except TypeError:
+        demurrage_timestamp = int(r)
+    demurrage_datetime = datetime.datetime.fromtimestamp(demurrage_timestamp)
+
+    total_seconds = block_start_timestamp - demurrage_timestamp
+    total_steps = total_seconds / 60
+
+    if total_steps < 1.0:
+        logg.error('only {} seconds since last demurrage application, skipping'.format(total_seconds))
+        return
+
+    logg.debug('block start is at {} demurrage is at {} -> {} minutes'.format(
+        block_start_datetime,
+        demurrage_datetime,
+        total_steps,
+        ))
+
+    rounds = 1
+    if config.get('_STEPS') > 0:
+        rounds = math.ceil(total_steps / config.get('_STEPS'))
+
+    logg.info('will perform {} rounds of {} steps'.format(rounds, config.get('_STEPS')))
+
+    last_tx_hash = None
+    for i in range(rounds):
+        signer = rpc.get_signer()
+        signer_address = rpc.get_sender_address()
+
+        nonce_oracle = rpc.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'):
+            print(tx_hash_hex)
+            conn.do(o)
+            if config.get('_WAIT_ALL') or (i == rounds - 1 and config.get('_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)
+        else:
+            print(o)
+
+
+
+if __name__ == '__main__':
+    main()

python/erc20_demurrage_token/runnable/deploy.py

@@ -49,8 +49,8 @@ arg_flags = chainlib.eth.cli.argflag_std_write
 argparser = chainlib.eth.cli.ArgumentParser(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', default=18, type=int, help='Token decimals')
+argparser.add_argument('--decimals', dest='token_decimals', type=int, help='Token decimals')
-argparser.add_argument('--sink-address', dest='sink_address', default=ZERO_ADDRESS, type=str, help='demurrage level,ppm per minute') 
+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')
@@ -90,7 +90,6 @@ 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()

python/erc20_demurrage_token/token.py

@@ -38,6 +38,15 @@ class DemurrageTokenSettings:
         self.sink_address = None
 
 
+    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):
 
     __abi = {}
@@ -380,6 +389,10 @@ class DemurrageToken(ERC20):
         return self.call_noarg('demurrageAmount', 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 supply_cap(self, contract_address, sender_address=ZERO_ADDRESS):
         return self.call_noarg('supplyCap', contract_address, sender_address=sender_address)
 

python/erc20_demurrage_token/unittest/base.py

@@ -32,18 +32,19 @@ PERIOD = 10
 
 class TestTokenDeploy:
 
-    def __init__(self, rpc, token_symbol='FOO', token_name='Foo Token', sink_address=ZERO_ADDRESS, supply=10**12):
+    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.tax_level = tax_level
-        self.period_seconds = PERIOD * 60
+        self.period_seconds = period * 60
 
         self.settings = DemurrageTokenSettings()
         self.settings.name = token_name
         self.settings.symbol = token_symbol
         self.settings.decimals = 6
-        self.settings.demurrage_level = TAX_LEVEL * (10 ** 32)
+        self.settings.demurrage_level = tax_level * (10 ** 32)
-        self.settings.period_minutes = PERIOD
+        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)
@@ -101,7 +102,12 @@ class TestDemurrage(EthTesterCase):
 #        self.start_time = token_deploy.start_time
 #        self.default_supply = self.default_supply
 #        self.default_supply_cap = self.default_supply_cap
-        self.deployer = TestTokenDeploy(self.rpc)
+        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
@@ -203,10 +209,11 @@ class TestDemurrageCap(TestDemurrage):
 class TestDemurrageUnit(TestDemurrage):
 
     def setUp(self):
-        super(TestDemurrage, self).setUp()
+        self.period = 1
+        self.period_seconds = self.period * 60
+        self.tax_level = TAX_LEVEL
 
-        self.tax_level = 50
+        super(TestDemurrageUnit, self).setUp()
-        self.period_seconds = 60
 
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         self.settings = DemurrageTokenSettings()

python/requirements.txt

@@ -1,3 +1,3 @@
-chainlib-eth~=0.0.27
+chainlib-eth>=0.1.0,<0.2.0
-eth-erc20~=0.1.10
+eth-erc20~=0.3.0
-funga-eth~=0.5.6
+funga-eth~=0.6.0

python/run_tests.sh

@@ -17,7 +17,12 @@ done
 modes=(SingleCap) # other contracts need to be updted
 for m in ${modes[@]}; do
 	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_period.py
-#	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution_unit.py
+done
+
+modes=(SingleNocap) # other contracts need to be updted
+for m in ${modes[@]}; do
+	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution_unit.py
+	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution_single.py
 done
 
 modes=(MultiCap SingleCap)

python/setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = erc20-demurrage-token
-version = 0.0.10
+version = 0.1.1
 description = ERC20 token with redistributed continual demurrage
 author = Louis Holbrook
 author_email = dev@holbrook.no
@@ -25,12 +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]
 * =
@@ -40,3 +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/tests/test_redistribution.py

@@ -31,6 +31,8 @@ testdir = os.path.dirname(__file__)
 
 class TestRedistribution(TestDemurrageDefault):
 
+
+
     def test_whole_is_parts(self):
         nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)

python/tests/test_redistribution_single.py

@@ -0,0 +1,185 @@
+# 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,
+        )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest.base import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+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, 10):
+            logg.debug('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)
+
+            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, supply, demurrage_previous, demurrage))
+
+            self.assert_within_lower(balance_minter + balance_sink, supply, 0.001)
+
+
+    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 * 10))
+
+        for i in range(1, 11):
+            logg.debug('checking period {}'.format(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)
+
+        i = 10
+        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, supply, demurrage_previous, demurrage))
+
+        self.assert_within_lower(balance_minter + balance_sink, supply, 0.001)
+
+
+#    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

@@ -31,12 +31,12 @@ testdir = os.path.dirname(__file__)
 
 class TestRedistribution(TestDemurrageUnit):
 
+
     # TODO: move to "pure" test file when getdistribution is implemented in all contracts
-    def test_distribution(self):
+    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**38)
         demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
         supply = self.default_supply
 
@@ -51,21 +51,23 @@ class TestRedistribution(TestDemurrageUnit):
         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**38)
+        demurrage = (1 - (self.tax_level / 100000)) * (10**28)
-        demurrage = (1 - (self.tax_level / 1000000)) * (10**28)
+
+        logg.debug('demurrage {}'.format(demurrage))
         supply = self.default_supply
 
-        o = c.to_redistribution(self.address, 0, demurrage, supply, 1, sender_address=self.accounts[0])
+        o = c.to_redistribution(self.address, 0, demurrage, 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)
+        expected_distribution = (self.default_supply * self.tax_level) / 100000
+        logg.debug('distribution {} supply {}'.format(distribution, self.default_supply))
         self.assert_within_lower(distribution, expected_distribution, 1000)
 
 
-    def test_single_step(self):
+    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)
 
@@ -81,6 +83,12 @@ class TestRedistribution(TestDemurrageUnit):
 
         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)
@@ -175,9 +183,6 @@ class TestRedistribution(TestDemurrageUnit):
         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.demurrage_amount(self.address, sender_address=self.accounts[0])
-#        r = self.rpc.do(o)
-#        demurrage = c.parse_demurrage_amount(r)
         logg.debug('\nrediistribution {}\ndemurrage {}\nsupply {}'.format(redistribution, demurrage, supply))
 
         expected_balance = int(supply * (self.tax_level / 1000000))

solidity/DemurrageTokenSingleNocap.sol

@@ -20,8 +20,6 @@ contract DemurrageTokenSingleCap {
 	// Cached demurrage amount, ppm with 38 digit resolution
 	uint128 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;
 
@@ -42,8 +40,11 @@ contract DemurrageTokenSingleCap {
 	// Implements ERC20
 	uint256 public totalSupply;
 
-	// Minimum amount of (demurraged) tokens an account must spend to participate in redistribution for a particular period
+	// Last executed period
-	uint256 public minimumParticipantSpend;
+	uint256 public lastPeriod;
+
+	// Last sink redistribution amount
+	uint256 public totalSink;
 
 	// 128 bit resolution of the demurrage divisor
 	// (this constant x 1000000 is contained within 128 bits)
@@ -71,7 +72,7 @@ contract DemurrageTokenSingleCap {
 	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; 
 
 	// Implements ERC20
 	event Transfer(address indexed _from, address indexed _to, uint256 _value);
@@ -111,17 +112,13 @@ contract DemurrageTokenSingleCap {
 		demurrageTimestamp = block.timestamp;
 		periodStart = demurrageTimestamp;
 		periodDuration = _periodMinutes * 60;
-		//demurrageAmount = 100000000000000000000000000000000000000 - _taxLevelMinute; // Represents 38 decimal places, same as resolutionFactor
+		demurrageAmount = uint128(nanoDivider) * 100;
-		//demurrageAmount = 100000000000000000000000000000000000000;
-		demurrageAmount = 10000000000000000000000000000;
-		//demurragePeriod = 1;
 		taxLevel = _taxLevelMinute; // Represents 38 decimal places
 		bytes32 initialRedistribution = toRedistribution(0, demurrageAmount, 0, 1);
 		redistributions.push(initialRedistribution);
 
 		// Misc settings
 		sinkAddress = _defaultSinkAddress;
-		minimumParticipantSpend = 10 ** uint256(_decimals);
 	}
 
 
@@ -153,10 +150,8 @@ contract DemurrageTokenSingleCap {
 
 		baseBalance = baseBalanceOf(_account);
 
-		//periodCount = actualPeriod() - demurragePeriod; 
 		periodCount = getMinutesDelta(demurrageTimestamp);
 
-		//currentDemurragedAmount = uint128(decayBy(demurrageAmount, periodCount));
 		currentDemurragedAmount = uint128(decayBy(demurrageAmount * 10000000000, periodCount));
 
 		return (baseBalance * currentDemurragedAmount) / (nanoDivider * 1000000000000);
@@ -254,7 +249,6 @@ contract DemurrageTokenSingleCap {
 		uint256 currentRedistribution;
 		uint256 grownSupply;
 
-		//grownSupply = growBy(totalSupply, 1);
 		grownSupply = totalSupply;
 		currentRedistribution = uint256(redistributions[redistributions.length-1]);
 		currentRedistribution &= (~maskRedistributionValue);
@@ -274,7 +268,7 @@ contract DemurrageTokenSingleCap {
 		bytes32 lastRedistribution;
 		uint256 currentPeriod;
 
-		lastRedistribution =  redistributions[redistributions.length-1];
+		lastRedistribution =  redistributions[lastPeriod];
 		currentPeriod = this.actualPeriod();
 		if (currentPeriod <= toRedistributionPeriod(lastRedistribution)) {
 			return bytes32(0x00);
@@ -285,8 +279,7 @@ contract DemurrageTokenSingleCap {
 	function getDistribution(uint256 _supply, uint256 _demurrageAmount) public view returns (uint256) {
 		uint256 difference;
 
-		//difference = _supply * (resolutionFactor - _demurrageAmount); //(nanoDivider - ((resolutionFactor - _demurrageAmount) / nanoDivider));
+		difference = _supply * (resolutionFactor - (_demurrageAmount * 10000000000));
-		difference = _supply * (resolutionFactor - (_demurrageAmount * 10000000000)); //(nanoDivider - ((resolutionFactor - _demurrageAmount) / nanoDivider));
 		return difference / resolutionFactor;
 	}
 
@@ -302,9 +295,13 @@ contract DemurrageTokenSingleCap {
 	// Returns the amount sent to the sink address
 	function applyDefaultRedistribution(bytes32 _redistribution) private returns (uint256) {
 		uint256 unit;
+		uint256 baseUnit;
 	
 		unit = getDistributionFromRedistribution(_redistribution);	
-		increaseBaseBalance(sinkAddress, toBaseAmount(unit));
+		baseUnit = toBaseAmount(unit) - totalSink;
+		increaseBaseBalance(sinkAddress, baseUnit);
+		lastPeriod += 1;
+		totalSink += baseUnit;
 		return unit;
 	}
 
@@ -319,13 +316,9 @@ contract DemurrageTokenSingleCap {
 	}
 
 	function applyDemurrageLimited(uint256 _rounds) public returns (bool) {
-		//uint128 epochPeriodCount;
 		uint256 periodCount;
 		uint256 lastDemurrageAmount;
 
-		//epochPeriodCount = actualPeriod();
-		//periodCount = epochPeriodCount - demurragePeriod;
-
 		periodCount = getMinutesDelta(demurrageTimestamp);
 		if (periodCount == 0) {
 			return false;
@@ -423,7 +416,6 @@ contract DemurrageTokenSingleCap {
 
 	// Inflates the given amount according to the current demurrage modifier
 	function toBaseAmount(uint256 _value) public view returns (uint256) {
-		//return (_value * resolutionFactor) / demurrageAmount;
 		return (_value * resolutionFactor) / (demurrageAmount * 10000000000);
 	}
 
@@ -474,7 +466,6 @@ contract DemurrageTokenSingleCap {
 		decreaseBaseBalance(_from, _value);
 		increaseBaseBalance(_to, _value);
 
-		//period = actualPeriod();
 		return true;
 	}