Add demurrage token amount adjust task

apps/cic-eth-aux/erc20-demurrage-token/cic_eth_aux/erc20_demurrage_token/__init__.py

@@ -0,0 +1,53 @@
+# standard imports
+import logging
+
+# external imports
+import celery
+from erc20_demurrage_token.demurrage import DemurrageCalculator
+from chainlib.connection import RPCConnection
+from chainlib.chain import ChainSpec
+from chainlib.eth.constant import ZERO_ADDRESS
+from cic_eth_registry import CICRegistry
+
+logg = logging.getLogger(__name__)
+
+celery_app = celery.current_app
+
+
+class NoopCalculator:
+
+    def amount_since(self, amount, timestamp):
+        logg.debug('noopcalculator amount {} timestamp {}'.format(amount, timestamp))
+        return amount
+
+
+class DemurrageCalculationTask(celery.Task):
+
+    demurrage_token_calcs = {}
+
+    @classmethod
+    def register_token(cls, rpc, chain_spec, token_symbol, sender_address=ZERO_ADDRESS):
+        registry = CICRegistry(chain_spec, rpc)
+        token_address = registry.by_name(token_symbol, sender_address=sender_address)
+        try:
+            c = DemurrageCalculator.from_contract(rpc, chain_spec, token_address, sender_address=sender_address)
+            logg.info('found demurrage calculator for ERC20 {} @ {}'.format(token_symbol, token_address))
+        except:
+            logg.warning('Token {} at address {} does not appear to be a demurrage contract. Calls to balance adjust for this token will always return the same amount'.format(token_symbol, token_address))
+            c = NoopCalculator()
+
+        cls.demurrage_token_calcs[token_symbol] = c
+
+
+@celery_app.task(bind=True, base=DemurrageCalculationTask)
+def get_adjusted_balance(self, token_symbol, amount, timestamp):
+    c = self.demurrage_token_calcs[token_symbol]
+    return c.amount_since(amount, timestamp)
+
+
+def aux_setup(rpc, config, sender_address=ZERO_ADDRESS):
+    chain_spec_str = config.get('CIC_CHAIN_SPEC')
+    chain_spec = ChainSpec.from_chain_str(chain_spec_str)
+    token_symbol = config.get('CIC_DEFAULT_TOKEN_SYMBOL')
+    
+    DemurrageCalculationTask.register_token(rpc, chain_spec, token_symbol, sender_address=sender_address)

apps/cic-eth-aux/erc20-demurrage-token/cic_eth_aux/erc20_demurrage_token/api.py

@@ -0,0 +1,30 @@
+# standard imports
+import logging
+
+# external imports 
+import celery
+from cic_eth.api.base import ApiBase
+
+app = celery.current_app
+
+logg = logging.getLogger(__name__)
+
+
+class Api(ApiBase):
+   
+    def get_adjusted_balance(self, token_symbol, balance, timestamp):
+        s = celery.signature(
+                'cic_eth_aux.erc20_demurrage_token.get_adjusted_balance',
+                [
+                    token_symbol,
+                    balance,
+                    timestamp,
+                    ],
+                queue=None,
+                )
+        if self.callback_param != None:
+            s.link(self.callback_success)
+            s.link.on_error(self.callback_error)
+
+        t = s.apply_async(queue=self.queue)
+        return t