def make_block(self, prev_block, txs, pubkey):
"""
After mempool changes at 0.011c version, make block must select valid transactions.
Mempool is mixed and not all transactions may be valid at the same time.
Miner creates a block by adding transactions that are valid together.
:param prev_block:
:param txs:
:param pubkey:
:return:
"""
leng = int(prev_block['length']) + 1
target_ = self.blockchain.target(leng)
diffLength = tools.hex_sum(prev_block['diffLength'],
tools.hex_invert(target_))
txs = self.statedb.get_valid_txs_for_next_block(txs, leng)
txs = [self.make_mint(pubkey)] + txs
out = {
'version': custom.version,
'txs': txs,
'length': leng,
'time': time.time(),
'diffLength': diffLength,
'target': target_,
'prevHash': tools.det_hash(prev_block)
}
return out
def genesis(self, pubkey):
target_ = self.blockchain.target(0)
out = {
'version': custom.version,
'length': 0,
'time': time.time(),
'target': target_,
'diffLength': tools.hex_invert(target_),
'txs': [self.make_mint(pubkey)]
}
return out
def make_block(self, prev_block, txs, pubkey):
leng = int(prev_block['length']) + 1
target_ = self.blockchain.target(leng)
diffLength = tools.hex_sum(prev_block['diffLength'],
tools.hex_invert(target_))
out = {
'version': custom.version,
'txs': txs + [self.make_mint(pubkey)],
'length': leng,
'time': time.time(),
'diffLength': diffLength,
'target': target_,
'prevHash': tools.det_hash(prev_block)
}
return out
def estimate_target():
"""
We are actually interested in the average number of hashes required to
mine a block. number of hashes required is inversely proportional
to target. So we average over inverse-targets, and inverse the final
answer. """
def sumTargets(l):
if len(l) < 1:
return 0
while len(l) > 1:
l = [tools.hex_sum(l[0], l[1])] + l[2:]
return l[0]
targets = self.recent_blockthings('targets', custom.history_length)
w = weights(len(targets)) # should be rat instead of float
tw = sum(w)
targets = list(map(tools.hex_invert, targets))
weighted_targets = [
targetTimesFloat(targets[i], w[i] / tw)
for i in range(len(targets))
]
return tools.hex_invert(sumTargets(weighted_targets))
def add_block(self, block):
"""Attempts adding a new block to the blockchain.
Median is good for weeding out liars, so long as the liars don't have 51%
hashpower. """
length = self.db.get('length')
if int(block['length']) < int(length) + 1:
return 1
elif int(block['length']) > int(length) + 1:
return 2
if (length >= 0 and block['diffLength'] != tools.hex_sum(self.db.get('diffLength'), tools.hex_invert(block['target']))) \
or (length < 0 and block['diffLength'] != tools.hex_invert(block['target'])):
tools.log(block['diffLength'])
tools.log(
tools.hex_sum(self.db.get('diffLength'),
tools.hex_invert(block['target'])))
tools.log(block['length'])
tools.log('difflength is wrong')
return 3
if length >= 0 and tools.det_hash(
self.db.get(length)) != block['prevHash']:
tools.log('prevhash different')
return 3
nonce_and_hash = tools.hash_without_nonce(block)
if tools.det_hash(nonce_and_hash) > block['target']:
tools.log('hash value does not match the target')
return 3
if block['target'] != self.target(block['length']):
tools.log('block: ' + str(block))
tools.log('target: ' + str(self.target(block['length'])))
tools.log('wrong target')
return 3
recent_time_values = self.recent_blockthings(
'times', custom.median_block_time_limit, self.db.get('length'))
median_block = tools.median(recent_time_values)
if block['time'] < median_block:
tools.log('Received block is generated earlier than median.')
return 3
if not self.account.update_accounts_with_block(
block, add_flag=True, simulate=True):
tools.log('Received block failed transactions check.')
return 3
self.db.put(block['length'], block)
self.db.put('length', block['length'])
self.db.put('diffLength', block['diffLength'])
orphans = self.tx_pool_pop_all()
self.account.update_accounts_with_block(block, add_flag=True)
for orphan in sorted(orphans, key=lambda x: x['count']):
self.add_tx(orphan)
return 0
def add_block(self, block):
"""Attempts adding a new block to the blockchain.
Median is good for weeding out liars, so long as the liars don't have 51%
hashpower. """
length = self.db.get('length')
block_at_length = self.get_block(length)
if int(block['length']) < int(length) + 1:
return 1
elif int(block['length']) > int(length) + 1:
return 2
tools.echo('add block: ' + str(block['length']))
if (length >= 0 and block['diffLength'] != tools.hex_sum(block_at_length['diffLength'],
tools.hex_invert(block['target']))) \
or (length < 0 and block['diffLength'] != tools.hex_invert(block['target'])):
tools.log(block['diffLength'])
tools.log(
tools.hex_sum(self.db.get('diffLength'),
tools.hex_invert(block['target'])))
tools.log(block['length'])
tools.log('difflength is wrong')
return 3
if length >= 0 and tools.det_hash(
block_at_length) != block['prevHash']:
tools.log('prevhash different')
return 3
nonce_and_hash = tools.hash_without_nonce(block)
if tools.det_hash(nonce_and_hash) > block['target']:
tools.log('hash value does not match the target')
return 3
if block['target'] != self.target(block['length']):
tools.log('block: ' + str(block))
tools.log('target: ' + str(self.target(block['length'])))
tools.log('wrong target')
return 3
"""
recent_time_values = self.recent_blockthings('times', custom.median_block_time_limit)
median_block = tools.median(recent_time_values)
if block['time'] < median_block:
tools.log('Received block is generated earlier than median.')
return 3
"""
# Check that block includes exactly one mint transaction
if 'txs' not in block:
tools.log(
'Received block does not include txs. At least a coinbase tx must be present'
)
return 3
# Sum of all mint type transactions must be one
mint_present = sum(
[0 if tx['type'] != 'mint' else 1 for tx in block['txs']])
if mint_present != 1:
tools.log('Received block includes wrong amount of mint txs')
return 3
for tx in block['txs']:
if not BlockchainService.tx_integrity_check(tx).getFlag():
tools.log('Received block failed special txs check.')
return 3
if not self.statedb.update_database_with_block(block):
return 3
self.put_block(block['length'], block)
self.db.put('length', block['length'])
self.db.put('diffLength', block['diffLength'])
orphans = self.tx_pool_pop_all()
for orphan in sorted(orphans,
key=lambda x: x['count'] if 'count' in x else -1):
self.tx_queue.put(orphan)
tools.techo('add block: ' + str(block['length']))
return 0