def log_filter(chain, address, signature, topics):
bn = chain.web3.eth.blockNumber
topics = topics[:]
if topics is not None:
for i in range(len(topics)):
topics[i] = a2t(topics[i])
# "LogAnonymous()"
# "NewChannel(address, address, bytes32)"
enc_sig = eth_utils.encode_hex(event_signature_to_log_topic(signature))
topics.insert(0, enc_sig)
obj = {
'fromBlock': bn,
'toBlock': "latest",
'address': address,
'topics': topics
}
return (chain, chain.web3.eth.filter(obj).filter_id, enc_sig)
def _encode_to_topic(event_signature):
return event_signature_to_log_topic(event_signature)
class LogTopics:
LogAnonymous = encode_hex(event_signature_to_log_topic("LogAnonymous()"))
LogNoArguments = encode_hex(event_signature_to_log_topic("LogNoArguments()"))
LogSingleArg = encode_hex(event_signature_to_log_topic("LogSingleArg(uint256)"))
LogSingleAnonymous = encode_hex(event_signature_to_log_topic("LogSingleAnonymous(uint256)"))
LogSingleWithIndex = encode_hex(event_signature_to_log_topic("LogSingleWithIndex(uint256)"))
LogDoubleArg = encode_hex(event_signature_to_log_topic("LogDoubleArg(uint256,uint256)"))
LogDoubleAnonymous = encode_hex(event_signature_to_log_topic("LogDoubleAnonymous(uint256,uint256)")) # noqa: E501
LogDoubleWithIndex = encode_hex(event_signature_to_log_topic("LogDoubleWithIndex(uint256,uint256)")) # noqa: E501
LogTripleArg = encode_hex(event_signature_to_log_topic("LogTripleArg(uint256,uint256,uint256)"))
LogTripleWithIndex = encode_hex(event_signature_to_log_topic("LogTripleWithIndex(uint256,uint256,uint256)")) # noqa: E501
LogQuadrupleArg = encode_hex(event_signature_to_log_topic("LogQuadrupleArg(uint256,uint256,uint256,uint256)")) # noqa: E501
LogQuadrupleWithIndex = encode_hex(event_signature_to_log_topic("LogQuadrupleWithIndex(uint256,uint256,uint256,uint256)")) # noqa: E501
LogBytes = encode_hex(event_signature_to_log_topic("LogBytes(bytes)"))
LogString = encode_hex(event_signature_to_log_topic("LogString(string)"))
LogDynamicArgs = encode_hex(event_signature_to_log_topic("LogDynamicArgs(string,string)"))
LogListArgs = encode_hex(event_signature_to_log_topic("LogListArgs(bytes2[],bytes2[])"))
LogAddressIndexed = encode_hex(event_signature_to_log_topic(
"LogAddressIndexed(address,address)"))
LogAddressNotIndexed = encode_hex(event_signature_to_log_topic(
"LogAddressNotIndexed(address,address)"))
CollationHeader, )
class NextLogUnavailable(Exception):
pass
class NoCandidateHead(Exception):
pass
# For handling logs filtering
# Event:
# CollationAdded(indexed uint256 shard, bytes collationHeader, bool isNewHead, uint256 score)
COLLATION_ADDED_TOPIC = event_signature_to_log_topic(
"CollationAdded(int128,int128,bytes32,bytes32,bytes32,address,bytes32,bytes32,int128,bool,int128)" # noqa: E501
)
@to_dict
def parse_collation_added_log(log):
# `shard_id` is the first indexed entry,hence the second entry in topics
shard_id_bytes32 = log['topics'][1]
data_bytes = decode_hex(log['data'])
header_bytes = shard_id_bytes32 + data_bytes[:-64]
is_new_head = bool(big_endian_to_int(data_bytes[-64:-32]))
score = big_endian_to_int(data_bytes[-32:])
collation_header = CollationHeader.from_bytes(header_bytes)
yield 'header', collation_header
yield 'is_new_head', is_new_head
yield 'score', score
class LogTopics(object):
LogAnonymous = encode_hex(event_signature_to_log_topic("LogAnonymous()"))
LogNoArguments = encode_hex(
event_signature_to_log_topic("LogNoArguments()"))
LogSingleArg = encode_hex(
event_signature_to_log_topic("LogSingleArg(uint256)"))
LogSingleAnonymous = encode_hex(
event_signature_to_log_topic("LogSingleAnonymous(uint256)"))
LogSingleWithIndex = encode_hex(
event_signature_to_log_topic("LogSingleWithIndex(uint256)"))
LogDoubleArg = encode_hex(
event_signature_to_log_topic("LogDoubleArg(uint256,uint256)"))
LogDoubleAnonymous = encode_hex(
event_signature_to_log_topic("LogDoubleAnonymous(uint256,uint256)"))
LogDoubleWithIndex = encode_hex(
event_signature_to_log_topic("LogDoubleWithIndex(uint256,uint256)"))
LogTripleArg = encode_hex(
event_signature_to_log_topic("LogTripleArg(uint256,uint256,uint256)"))
LogTripleWithIndex = encode_hex(
event_signature_to_log_topic(
"LogTripleWithIndex(uint256,uint256,uint256)"))
LogQuadrupleArg = encode_hex(
event_signature_to_log_topic(
"LogQuadrupleArg(uint256,uint256,uint256,uint256)"))
LogQuadrupleWithIndex = encode_hex(
event_signature_to_log_topic(
"LogQuadrupleWithIndex(uint256,uint256,uint256,uint256)"))
LogBytes = encode_hex(event_signature_to_log_topic("LogBytes(bytes)"))
LogString = encode_hex(event_signature_to_log_topic("LogString(string)"))
LogDynamicArgs = encode_hex(
event_signature_to_log_topic("LogDynamicArgs(string,string)"))
class ShardTracker:
'''Track logs `CollationAdded` in mainchain
'''
# For handling logs filtering
# Event:
# CollationAdded(indexed uint256 shard, bytes collationHeader, bool isNewHead, uint256 score)
COLLATION_ADDED_TOPIC = event_signature_to_log_topic(
"CollationAdded(int128,int128,bytes32,bytes32,bytes32,address,bytes32,bytes32,int128,bool,int128)" # noqa: E501
)
# older <---------------> newer
current_score = None
new_logs = None
unchecked_logs = None
def __init__(self, shard_id, log_handler, vmc_address):
# TODO: currently set one log_handler for each shard. Should see if there is a better way
# to make one log_handler shared over all shards.
self.shard_id = shard_id
self.log_handler = log_handler
self.vmc_address = vmc_address
self.current_score = None
# older <---------------> newer
self.new_logs = []
self.unchecked_logs = []
@to_tuple
def _get_new_logs(self):
shard_id_topic_hex = encode_hex(
self.shard_id.to_bytes(32, byteorder='big'))
new_logs = self.log_handler.get_new_logs(
address=self.vmc_address,
topics=[
encode_hex(self.COLLATION_ADDED_TOPIC),
shard_id_topic_hex,
],
)
for log in new_logs:
yield parse_collation_added_log(log)
def get_next_log(self):
new_logs = self._get_new_logs()
self.new_logs.extend(new_logs)
if len(self.new_logs) == 0:
raise NextLogUnavailable("No more next logs")
return self.new_logs.pop()
# TODO: this method may return wrong result when new logs arrive before the logs inside
# `self.new_logs` are consumed entirely. This issue can be resolved by saving the
# status of `new_logs`, `unchecked_logs`, and `current_score`, when it start to run
# `GUESS_HEAD`. If there is a new block arriving, just restore them to the saved status,
# append new logs to `new_logs`, and re-run `GUESS_HEAD`
def fetch_candidate_head(self):
# Try to return a log that has the score that we are checking for,
# checking in order of oldest to most recent.
unchecked_logs = pipe(
self.unchecked_logs,
enumerate,
tuple,
reversed,
tuple,
)
current_score = self.current_score
for idx, logs_entry in unchecked_logs:
if logs_entry['score'] == current_score:
return self.unchecked_logs.pop(idx)
# If no further recorded but unchecked logs exist, go to the next
# is_new_head = true log
while True:
# TODO: currently just raise when there is no log anymore
log_entry = self.get_next_log()
if log_entry['is_new_head']:
break
self.unchecked_logs.append(log_entry)
self.current_score = log_entry['score']
return log_entry