import time
import asyncio
import typing
from bisect import bisect_right
from struct import pack, unpack
from concurrent.futures.thread import ThreadPoolExecutor
from typing import Optional, List, Tuple, Set, DefaultDict, Dict
from prometheus_client import Gauge, Histogram
from collections import defaultdict
import lbry
from lbry.schema.claim import Claim
from lbry.schema.mime_types import guess_stream_type
from lbry.wallet.ledger import Ledger, TestNetLedger, RegTestLedger
from lbry.wallet.constants import TXO_TYPES
from lbry.wallet.server.db.common import STREAM_TYPES, CLAIM_TYPES
from lbry.wallet.transaction import OutputScript, Output, Transaction
from lbry.wallet.server.tx import Tx, TxOutput, TxInput
from lbry.wallet.server.daemon import DaemonError
from lbry.wallet.server.hash import hash_to_hex_str, HASHX_LEN
from lbry.wallet.server.util import chunks, class_logger
from lbry.crypto.hash import hash160
from lbry.wallet.server.leveldb import FlushData
from lbry.wallet.server.db import DB_PREFIXES
from lbry.wallet.server.db.claimtrie import StagedClaimtrieItem, StagedClaimtrieSupport
from lbry.wallet.server.db.claimtrie import get_takeover_name_ops, StagedActivation, get_add_effective_amount_ops
from lbry.wallet.server.db.claimtrie import get_remove_name_ops, get_remove_effective_amount_ops
from lbry.wallet.server.db.prefixes import ACTIVATED_SUPPORT_TXO_TYPE, ACTIVATED_CLAIM_TXO_TYPE
from lbry.wallet.server.db.prefixes import PendingActivationKey, PendingActivationValue, Prefixes
from lbry.wallet.server.udp import StatusServer
from lbry.wallet.server.db.revertable import RevertableOp, RevertablePut, RevertableDelete
if typing.TYPE_CHECKING:
from lbry.wallet.server.leveldb import LevelDB
class Prefetcher:
"""Prefetches blocks (in the forward direction only)."""
def __init__(self, daemon, coin, blocks_event):
self.logger = class_logger(__name__, self.__class__.__name__)
self.daemon = daemon
self.coin = coin
self.blocks_event = blocks_event
self.blocks = []
self.caught_up = False
# Access to fetched_height should be protected by the semaphore
self.fetched_height = None
self.semaphore = asyncio.Semaphore()
self.refill_event = asyncio.Event()
# The prefetched block cache size. The min cache size has
# little effect on sync time.
self.cache_size = 0
self.min_cache_size = 10 * 1024 * 1024
# This makes the first fetch be 10 blocks
self.ave_size = self.min_cache_size // 10
self.polling_delay = 5
async def main_loop(self, bp_height):
"""Loop forever polling for more blocks."""
await self.reset_height(bp_height)
while True:
try:
# Sleep a while if there is nothing to prefetch
await self.refill_event.wait()
if not await self._prefetch_blocks():
await asyncio.sleep(self.polling_delay)
except DaemonError as e:
self.logger.info(f'ignoring daemon error: {e}')
def get_prefetched_blocks(self):
"""Called by block processor when it is processing queued blocks."""
blocks = self.blocks
self.blocks = []
self.cache_size = 0
self.refill_event.set()
return blocks
async def reset_height(self, height):
"""Reset to prefetch blocks from the block processor's height.
Used in blockchain reorganisations. This coroutine can be
called asynchronously to the _prefetch_blocks coroutine so we
must synchronize with a semaphore.
"""
async with self.semaphore:
self.blocks.clear()
self.cache_size = 0
self.fetched_height = height
self.refill_event.set()
daemon_height = await self.daemon.height()
behind = daemon_height - height
if behind > 0:
self.logger.info(f'catching up to daemon height {daemon_height:,d} '
f'({behind:,d} blocks behind)')
else:
self.logger.info(f'caught up to daemon height {daemon_height:,d}')
async def _prefetch_blocks(self):
"""Prefetch some blocks and put them on the queue.
Repeats until the queue is full or caught up.
"""
daemon = self.daemon
daemon_height = await daemon.height()
async with self.semaphore:
while self.cache_size < self.min_cache_size:
# Try and catch up all blocks but limit to room in cache.
# Constrain fetch count to between 0 and 500 regardless;
# testnet can be lumpy.
cache_room = self.min_cache_size // self.ave_size
count = min(daemon_height - self.fetched_height, cache_room)
count = min(500, max(count, 0))
if not count:
self.caught_up = True
return False
first = self.fetched_height + 1
hex_hashes = await daemon.block_hex_hashes(first, count)
if self.caught_up:
self.logger.info('new block height {:,d} hash {}'
.format(first + count-1, hex_hashes[-1]))
blocks = await daemon.raw_blocks(hex_hashes)
assert count == len(blocks)
# Special handling for genesis block
if first == 0:
blocks[0] = self.coin.genesis_block(blocks[0])
self.logger.info(f'verified genesis block with hash {hex_hashes[0]}')
# Update our recent average block size estimate
size = sum(len(block) for block in blocks)
if count >= 10:
self.ave_size = size // count
else:
self.ave_size = (size + (10 - count) * self.ave_size) // 10
self.blocks.extend(blocks)
self.cache_size += size
self.fetched_height += count
self.blocks_event.set()
self.refill_event.clear()
return True
class ChainError(Exception):
"""Raised on error processing blocks."""
NAMESPACE = "wallet_server"
HISTOGRAM_BUCKETS = (
.005, .01, .025, .05, .075, .1, .25, .5, .75, 1.0, 2.5, 5.0, 7.5, 10.0, 15.0, 20.0, 30.0, 60.0, float('inf')
)
class BlockProcessor:
"""Process blocks and update the DB state to match.
Employ a prefetcher to prefetch blocks in batches for processing.
Coordinate backing up in case of chain reorganisations.
"""
block_count_metric = Gauge(
"block_count", "Number of processed blocks", namespace=NAMESPACE
)
block_update_time_metric = Histogram(
"block_time", "Block update times", namespace=NAMESPACE, buckets=HISTOGRAM_BUCKETS
)
reorg_count_metric = Gauge(
"reorg_count", "Number of reorgs", namespace=NAMESPACE
)
def __init__(self, env, db: 'LevelDB', daemon, notifications):
self.env = env
self.db = db
self.daemon = daemon
self.notifications = notifications
self.coin = env.coin
if env.coin.NET == 'mainnet':
self.ledger = Ledger
elif env.coin.NET == 'testnet':
self.ledger = TestNetLedger
else:
self.ledger = RegTestLedger
self.blocks_event = asyncio.Event()
self.prefetcher = Prefetcher(daemon, env.coin, self.blocks_event)
self.logger = class_logger(__name__, self.__class__.__name__)
self.executor = ThreadPoolExecutor(1)
# Meta
self.next_cache_check = 0
self.touched = set()
self.reorg_count = 0
# Caches of unflushed items.
self.headers = []
self.block_hashes = []
self.block_txs = []
self.undo_infos = []
# UTXO cache
self.utxo_cache = {}
self.db_deletes = []
# Claimtrie cache
self.claimtrie_stash = []
self.undo_claims = []
# If the lock is successfully acquired, in-memory chain state
# is consistent with self.height
self.state_lock = asyncio.Lock()
# self.search_cache = {}
self.history_cache = {}
self.status_server = StatusServer()
#################################
# attributes used for calculating stake activations and takeovers per block
#################################
# txo to pending claim
self.pending_claims: typing.Dict[Tuple[int, int], StagedClaimtrieItem] = {}
# claim hash to pending claim txo
self.pending_claim_txos: typing.Dict[bytes, Tuple[int, int]] = {}
# claim hash to lists of pending support txos
self.pending_supports: DefaultDict[bytes, List[Tuple[int, int]]] = defaultdict(list)
# support txo: (supported claim hash, support amount)
self.pending_support_txos: Dict[Tuple[int, int], Tuple[bytes, int]] = {}
# removed supports {name: {claim_hash: [(tx_num, nout), ...]}}
self.pending_removed_support: DefaultDict[str, DefaultDict[bytes, List[Tuple[int, int]]]] = defaultdict(
lambda: defaultdict(list))
self.staged_pending_abandoned: Dict[bytes, StagedClaimtrieItem] = {}
# removed activated support amounts by claim hash
self.removed_active_support: DefaultDict[bytes, List[int]] = defaultdict(list)
# pending activated support amounts by claim hash
self.staged_activated_support: DefaultDict[bytes, List[int]] = defaultdict(list)
# pending activated name and claim hash to claim/update txo amount
self.staged_activated_claim: Dict[Tuple[str, bytes], int] = {}
# pending claim and support activations per claim hash per name,
# used to process takeovers due to added activations
self.pending_activated: DefaultDict[str, DefaultDict[bytes, List[Tuple[PendingActivationKey, int]]]] = \
defaultdict(lambda: defaultdict(list))
# these are used for detecting early takeovers by not yet activated claims/supports
self.possible_future_activated_support: DefaultDict[bytes, List[int]] = defaultdict(list)
self.possible_future_activated_claim: Dict[Tuple[str, bytes], int] = {}
self.possible_future_support_txos: DefaultDict[bytes, List[Tuple[int, int]]] = defaultdict(list)
self.removed_claims_to_send_es = set()
self.touched_claims_to_send_es = set()
self.signatures_changed = set()
self.pending_reposted = set()
self.pending_channel_counts = defaultdict(lambda: 0)
self.pending_channels = {}
self.amount_cache = {}
def claim_producer(self):
if self.db.db_height <= 1:
return
to_send_es = set(self.touched_claims_to_send_es)
to_send_es.update(self.pending_reposted.difference(self.removed_claims_to_send_es))
to_send_es.update({k for k, v in self.pending_channel_counts.items() if v != 0}.difference(self.removed_claims_to_send_es))
for claim_hash in self.removed_claims_to_send_es:
yield 'delete', claim_hash.hex()
for claim in self.db.claims_producer(to_send_es):
yield 'update', claim
async def run_in_thread_with_lock(self, func, *args):
# Run in a thread to prevent blocking. Shielded so that
# cancellations from shutdown don't lose work - when the task
# completes the data will be flushed and then we shut down.
# Take the state lock to be certain in-memory state is
# consistent and not being updated elsewhere.
async def run_in_thread_locked():
async with self.state_lock:
return await asyncio.get_event_loop().run_in_executor(self.executor, func, *args)
return await asyncio.shield(run_in_thread_locked())
async def check_and_advance_blocks(self, raw_blocks):
"""Process the list of raw blocks passed. Detects and handles
reorgs.
"""
if not raw_blocks:
return
first = self.height + 1
blocks = [self.coin.block(raw_block, first + n)
for n, raw_block in enumerate(raw_blocks)]
headers = [block.header for block in blocks]
hprevs = [self.coin.header_prevhash(h) for h in headers]
chain = [self.tip] + [self.coin.header_hash(h) for h in headers[:-1]]
if hprevs == chain:
start = time.perf_counter()
try:
for block in blocks:
start = time.perf_counter()
await self.run_in_thread_with_lock(self.advance_block, block)
self.logger.info("advanced to %i in %0.3fs", self.height, time.perf_counter() - start)
# TODO: we shouldnt wait on the search index updating before advancing to the next block
await self.db.search_index.claim_consumer(self.claim_producer())
self.db.search_index.clear_caches()
self.touched_claims_to_send_es.clear()
self.removed_claims_to_send_es.clear()
self.pending_reposted.clear()
self.pending_channel_counts.clear()
# print("******************\n")
except:
self.logger.exception("advance blocks failed")
raise
# if self.sql:
# for cache in self.search_cache.values():
# cache.clear()
self.history_cache.clear() # TODO: is this needed?
self.notifications.notified_mempool_txs.clear()
processed_time = time.perf_counter() - start
self.block_count_metric.set(self.height)
self.block_update_time_metric.observe(processed_time)
self.status_server.set_height(self.db.fs_height, self.db.db_tip)
if not self.db.first_sync:
s = '' if len(blocks) == 1 else 's'
self.logger.info('processed {:,d} block{} in {:.1f}s'.format(len(blocks), s, processed_time))
if self._caught_up_event.is_set():
# if self.sql:
# await self.db.search_index.apply_filters(self.sql.blocked_streams, self.sql.blocked_channels,
# self.sql.filtered_streams, self.sql.filtered_channels)
await self.notifications.on_block(self.touched, self.height)
self.touched = set()
elif hprevs[0] != chain[0]:
await self.reorg_chain()
else:
# It is probably possible but extremely rare that what
# bitcoind returns doesn't form a chain because it
# reorg-ed the chain as it was processing the batched
# block hash requests. Should this happen it's simplest
# just to reset the prefetcher and try again.
self.logger.warning('daemon blocks do not form a chain; '
'resetting the prefetcher')
await self.prefetcher.reset_height(self.height)
async def reorg_chain(self, count: Optional[int] = None):
"""Handle a chain reorganisation.
Count is the number of blocks to simulate a reorg, or None for
a real reorg."""
if count is None:
self.logger.info('chain reorg detected')
else:
self.logger.info(f'faking a reorg of {count:,d} blocks')
async def get_raw_blocks(last_height, hex_hashes):
heights = range(last_height, last_height - len(hex_hashes), -1)
try:
blocks = [await self.db.read_raw_block(height) for height in heights]
self.logger.info(f'read {len(blocks)} blocks from disk')
return blocks
except FileNotFoundError:
return await self.daemon.raw_blocks(hex_hashes)
try:
await self.flush(True)
start, last, hashes = await self.reorg_hashes(count)
# Reverse and convert to hex strings.
hashes = [hash_to_hex_str(hash) for hash in reversed(hashes)]
self.logger.info("reorg %i block hashes", len(hashes))
for hex_hashes in chunks(hashes, 50):
raw_blocks = await get_raw_blocks(last, hex_hashes)
self.logger.info("got %i raw blocks", len(raw_blocks))
await self.run_in_thread_with_lock(self.backup_blocks, raw_blocks)
last -= len(raw_blocks)
await self.prefetcher.reset_height(self.height)
self.reorg_count_metric.inc()
except:
self.logger.exception("boom")
raise
finally:
self.logger.info("done with reorg")
async def reorg_hashes(self, count):
"""Return a pair (start, last, hashes) of blocks to back up during a
reorg.
The hashes are returned in order of increasing height. Start
is the height of the first hash, last of the last.
"""
start, count = await self.calc_reorg_range(count)
last = start + count - 1
s = '' if count == 1 else 's'
self.logger.info(f'chain was reorganised replacing {count:,d} '
f'block{s} at heights {start:,d}-{last:,d}')
return start, last, await self.db.fs_block_hashes(start, count)
async def calc_reorg_range(self, count: Optional[int]):
"""Calculate the reorg range"""
def diff_pos(hashes1, hashes2):
"""Returns the index of the first difference in the hash lists.
If both lists match returns their length."""
for n, (hash1, hash2) in enumerate(zip(hashes1, hashes2)):
if hash1 != hash2:
return n
return len(hashes)
if count is None:
# A real reorg
start = self.height - 1
count = 1
while start > 0:
hashes = await self.db.fs_block_hashes(start, count)
hex_hashes = [hash_to_hex_str(hash) for hash in hashes]
d_hex_hashes = await self.daemon.block_hex_hashes(start, count)
n = diff_pos(hex_hashes, d_hex_hashes)
if n > 0:
start += n
break
count = min(count * 2, start)
start -= count
count = (self.height - start) + 1
else:
start = (self.height - count) + 1
return start, count
# - Flushing
def flush_data(self):
"""The data for a flush. The lock must be taken."""
assert self.state_lock.locked()
return FlushData(self.height, self.tx_count, self.headers, self.block_hashes,
self.block_txs, self.claimtrie_stash, self.undo_infos, self.utxo_cache,
self.db_deletes, self.tip, self.undo_claims)
async def flush(self, flush_utxos):
def flush():
self.db.flush_dbs(self.flush_data())
await self.run_in_thread_with_lock(flush)
async def _maybe_flush(self):
# If caught up, flush everything as client queries are
# performed on the DB.
if self._caught_up_event.is_set():
await self.flush(True)
elif time.perf_counter() > self.next_cache_check:
await self.flush(True)
self.next_cache_check = time.perf_counter() + 30
def _add_claim_or_update(self, height: int, txo: 'Output', tx_hash: bytes, tx_num: int, nout: int,
spent_claims: typing.Dict[bytes, typing.Tuple[int, int, str]]) -> List['RevertableOp']:
try:
claim_name = txo.normalized_name
except UnicodeDecodeError:
claim_name = ''.join(chr(c) for c in txo.script.values['claim_name'])
if txo.script.is_claim_name:
claim_hash = hash160(tx_hash + pack('>I', nout))[::-1]
# print(f"\tnew {claim_hash.hex()} ({tx_num} {txo.amount})")
else:
claim_hash = txo.claim_hash[::-1]
# print(f"\tupdate {claim_hash.hex()} ({tx_num} {txo.amount})")
signing_channel_hash = None
channel_signature_is_valid = False
try:
signable = txo.signable
is_repost = txo.claim.is_repost
is_channel = txo.claim.is_channel
if txo.claim.is_signed:
signing_channel_hash = txo.signable.signing_channel_hash[::-1]
except: # google.protobuf.message.DecodeError: Could not parse JSON.
signable = None
is_repost = False
is_channel = False
ops = []
reposted_claim_hash = None
if is_repost:
reposted_claim_hash = txo.claim.repost.reference.claim_hash[::-1]
self.pending_reposted.add(reposted_claim_hash)
if is_channel:
self.pending_channels[claim_hash] = txo.claim.channel.public_key_bytes
raw_channel_tx = None
if signable and signable.signing_channel_hash:
signing_channel = self.db.get_claim_txo(signing_channel_hash)
if signing_channel:
raw_channel_tx = self.db.db.get(
DB_PREFIXES.TX_PREFIX.value + self.db.total_transactions[signing_channel.tx_num]
)
channel_pub_key_bytes = None
try:
if not signing_channel:
if txo.signable.signing_channel_hash[::-1] in self.pending_channels:
channel_pub_key_bytes = self.pending_channels[txo.signable.signing_channel_hash[::-1]]
elif raw_channel_tx:
chan_output = self.coin.transaction(raw_channel_tx).outputs[signing_channel.position]
chan_script = OutputScript(chan_output.pk_script)
chan_script.parse()
channel_meta = Claim.from_bytes(chan_script.values['claim'])
channel_pub_key_bytes = channel_meta.channel.public_key_bytes
if channel_pub_key_bytes:
channel_signature_is_valid = Output.is_signature_valid(
txo.get_encoded_signature(), txo.get_signature_digest(self.ledger), channel_pub_key_bytes
)
if channel_signature_is_valid:
self.pending_channel_counts[signing_channel_hash] += 1
except:
self.logger.exception(f"error validating channel signature for %s:%i", tx_hash[::-1].hex(), nout)
if txo.script.is_claim_name: # it's a root claim
root_tx_num, root_idx = tx_num, nout
else: # it's a claim update
if claim_hash not in spent_claims:
# print(f"\tthis is a wonky tx, contains unlinked claim update {claim_hash.hex()}")
return []
(prev_tx_num, prev_idx, _) = spent_claims.pop(claim_hash)
# print(f"\tupdate {claim_hash.hex()} {tx_hash[::-1].hex()} {txo.amount}")
if (prev_tx_num, prev_idx) in self.pending_claims:
previous_claim = self.pending_claims.pop((prev_tx_num, prev_idx))
root_tx_num, root_idx = previous_claim.root_claim_tx_num, previous_claim.root_claim_tx_position
else:
v = self.db.get_claim_txo(
claim_hash
)
root_tx_num, root_idx = v.root_tx_num, v.root_position
activation = self.db.get_activation(prev_tx_num, prev_idx)
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, claim_hash, prev_tx_num, prev_idx, activation, claim_name, v.amount
).get_remove_activate_ops()
)
pending = StagedClaimtrieItem(
claim_name, claim_hash, txo.amount, self.coin.get_expiration_height(height), tx_num, nout, root_tx_num,
root_idx, channel_signature_is_valid, signing_channel_hash, reposted_claim_hash
)
self.pending_claims[(tx_num, nout)] = pending
self.pending_claim_txos[claim_hash] = (tx_num, nout)
ops.extend(pending.get_add_claim_utxo_ops())
return ops
def _add_support(self, txo: 'Output', tx_num: int, nout: int) -> List['RevertableOp']:
supported_claim_hash = txo.claim_hash[::-1]
self.pending_supports[supported_claim_hash].append((tx_num, nout))
self.pending_support_txos[(tx_num, nout)] = supported_claim_hash, txo.amount
# print(f"\tsupport claim {supported_claim_hash.hex()} +{txo.amount}")
return StagedClaimtrieSupport(
supported_claim_hash, tx_num, nout, txo.amount
).get_add_support_utxo_ops()
def _add_claim_or_support(self, height: int, tx_hash: bytes, tx_num: int, nout: int, txo: 'Output',
spent_claims: typing.Dict[bytes, Tuple[int, int, str]]) -> List['RevertableOp']:
if txo.script.is_claim_name or txo.script.is_update_claim:
return self._add_claim_or_update(height, txo, tx_hash, tx_num, nout, spent_claims)
elif txo.script.is_support_claim or txo.script.is_support_claim_data:
return self._add_support(txo, tx_num, nout)
return []
def _spend_support_txo(self, txin):
txin_num = self.db.transaction_num_mapping[txin.prev_hash]
if (txin_num, txin.prev_idx) in self.pending_support_txos:
spent_support, support_amount = self.pending_support_txos.pop((txin_num, txin.prev_idx))
self.pending_supports[spent_support].remove((txin_num, txin.prev_idx))
supported_name = self._get_pending_claim_name(spent_support)
# print(f"\tspent support for {spent_support.hex()}")
self.pending_removed_support[supported_name][spent_support].append((txin_num, txin.prev_idx))
return StagedClaimtrieSupport(
spent_support, txin_num, txin.prev_idx, support_amount
).get_spend_support_txo_ops()
spent_support, support_amount = self.db.get_supported_claim_from_txo(txin_num, txin.prev_idx)
if spent_support:
supported_name = self._get_pending_claim_name(spent_support)
if supported_name is not None:
self.pending_removed_support[supported_name][spent_support].append((txin_num, txin.prev_idx))
activation = self.db.get_activation(txin_num, txin.prev_idx, is_support=True)
if 0 < activation < self.height + 1:
self.removed_active_support[spent_support].append(support_amount)
# print(f"\tspent support for {spent_support.hex()} activation:{activation} {support_amount}")
ops = StagedClaimtrieSupport(
spent_support, txin_num, txin.prev_idx, support_amount
).get_spend_support_txo_ops()
if supported_name is not None and activation > 0:
ops.extend(StagedActivation(
ACTIVATED_SUPPORT_TXO_TYPE, spent_support, txin_num, txin.prev_idx, activation, supported_name,
support_amount
).get_remove_activate_ops())
return ops
return []
def _spend_claim_txo(self, txin: TxInput, spent_claims: Dict[bytes, Tuple[int, int, str]]):
txin_num = self.db.transaction_num_mapping[txin.prev_hash]
if (txin_num, txin.prev_idx) in self.pending_claims:
spent = self.pending_claims[(txin_num, txin.prev_idx)]
else:
spent_claim_hash_and_name = self.db.get_claim_from_txo(
txin_num, txin.prev_idx
)
if not spent_claim_hash_and_name: # txo is not a claim
return []
claim_hash = spent_claim_hash_and_name.claim_hash
signing_hash = self.db.get_channel_for_claim(claim_hash)
v = self.db.get_claim_txo(claim_hash)
reposted_claim_hash = self.db.get_repost(claim_hash)
spent = StagedClaimtrieItem(
v.name, claim_hash, v.amount,
self.coin.get_expiration_height(bisect_right(self.db.tx_counts, txin_num)),
txin_num, txin.prev_idx, v.root_tx_num, v.root_position, v.channel_signature_is_valid, signing_hash,
reposted_claim_hash
)
if spent.reposted_claim_hash:
self.pending_reposted.add(spent.reposted_claim_hash)
if spent.signing_hash and spent.channel_signature_is_valid:
self.pending_channel_counts[spent.signing_hash] -= 1
spent_claims[spent.claim_hash] = (spent.tx_num, spent.position, spent.name)
# print(f"\tspend lbry://{spent.name}#{spent.claim_hash.hex()}")
return spent.get_spend_claim_txo_ops()
def _spend_claim_or_support_txo(self, txin, spent_claims):
spend_claim_ops = self._spend_claim_txo(txin, spent_claims)
if spend_claim_ops:
return spend_claim_ops
return self._spend_support_txo(txin)
def _abandon_claim(self, claim_hash, tx_num, nout, name) -> List['RevertableOp']:
if (tx_num, nout) in self.pending_claims:
pending = self.pending_claims.pop((tx_num, nout))
self.staged_pending_abandoned[pending.claim_hash] = pending
claim_root_tx_num, claim_root_idx = pending.root_claim_tx_num, pending.root_claim_tx_position
prev_amount, prev_signing_hash = pending.amount, pending.signing_hash
reposted_claim_hash = pending.reposted_claim_hash
expiration = self.coin.get_expiration_height(self.height)
signature_is_valid = pending.channel_signature_is_valid
else:
v = self.db.get_claim_txo(
claim_hash
)
claim_root_tx_num, claim_root_idx, prev_amount = v.root_tx_num, v.root_position, v.amount
signature_is_valid = v.channel_signature_is_valid
prev_signing_hash = self.db.get_channel_for_claim(claim_hash)
reposted_claim_hash = self.db.get_repost(claim_hash)
expiration = self.coin.get_expiration_height(bisect_right(self.db.tx_counts, tx_num))
self.staged_pending_abandoned[claim_hash] = staged = StagedClaimtrieItem(
name, claim_hash, prev_amount, expiration, tx_num, nout, claim_root_tx_num,
claim_root_idx, signature_is_valid, prev_signing_hash, reposted_claim_hash
)
if prev_signing_hash and prev_signing_hash in self.pending_channel_counts:
self.pending_channel_counts.pop(prev_signing_hash)
for support_txo_to_clear in self.pending_supports[claim_hash]:
self.pending_support_txos.pop(support_txo_to_clear)
self.pending_supports[claim_hash].clear()
self.pending_supports.pop(claim_hash)
ops = []
if staged.name.startswith('@'): # abandon a channel, invalidate signatures
for k, claim_hash in self.db.db.iterator(prefix=Prefixes.channel_to_claim.pack_partial_key(staged.claim_hash)):
if claim_hash in self.staged_pending_abandoned:
continue
self.signatures_changed.add(claim_hash)
if claim_hash in self.pending_claims:
claim = self.pending_claims[claim_hash]
else:
claim = self.db.get_claim_txo(claim_hash)
assert claim is not None
ops.extend([
RevertableDelete(k, claim_hash),
RevertableDelete(
*Prefixes.claim_to_txo.pack_item(
claim_hash, claim.tx_num, claim.position, claim.root_tx_num, claim.root_position,
claim.amount, claim.channel_signature_is_valid, claim.name
)
),
RevertablePut(
*Prefixes.claim_to_txo.pack_item(
claim_hash, claim.tx_num, claim.position, claim.root_tx_num, claim.root_position,
claim.amount, False, claim.name
)
)
])
if staged.signing_hash:
ops.append(RevertableDelete(*Prefixes.claim_to_channel.pack_item(staged.claim_hash, staged.signing_hash)))
return ops
def _abandon(self, spent_claims) -> List['RevertableOp']:
# Handle abandoned claims
ops = []
for abandoned_claim_hash, (tx_num, nout, name) in spent_claims.items():
# print(f"\tabandon {abandoned_claim_hash.hex()} {tx_num} {nout}")
ops.extend(self._abandon_claim(abandoned_claim_hash, tx_num, nout, name))
return ops
def _expire_claims(self, height: int):
expired = self.db.get_expired_by_height(height)
spent_claims = {}
ops = []
for expired_claim_hash, (tx_num, position, name, txi) in expired.items():
if (tx_num, position) not in self.pending_claims:
ops.extend(self._spend_claim_txo(txi, spent_claims))
if expired:
# do this to follow the same content claim removing pathway as if a claim (possible channel) was abandoned
ops.extend(self._abandon(spent_claims))
return ops
def _cached_get_active_amount(self, claim_hash: bytes, txo_type: int, height: int) -> int:
if (claim_hash, txo_type, height) in self.amount_cache:
return self.amount_cache[(claim_hash, txo_type, height)]
self.amount_cache[(claim_hash, txo_type, height)] = amount = self.db._get_active_amount(
claim_hash, txo_type, height
)
return amount
def _cached_get_effective_amount(self, claim_hash: bytes, support_only=False) -> int:
support_amount = self._cached_get_active_amount(claim_hash, ACTIVATED_SUPPORT_TXO_TYPE, self.db.db_height + 1)
if support_only:
return support_only
return support_amount + self._cached_get_active_amount(
claim_hash, ACTIVATED_CLAIM_TXO_TYPE, self.db.db_height + 1
)
def _get_pending_claim_amount(self, name: str, claim_hash: bytes, height=None) -> int:
if (name, claim_hash) in self.staged_activated_claim:
return self.staged_activated_claim[(name, claim_hash)]
if (name, claim_hash) in self.possible_future_activated_claim:
return self.possible_future_activated_claim[(name, claim_hash)]
return self._cached_get_active_amount(claim_hash, ACTIVATED_CLAIM_TXO_TYPE, height or (self.height + 1))
def _get_pending_claim_name(self, claim_hash: bytes) -> Optional[str]:
assert claim_hash is not None
if claim_hash in self.pending_claims:
return self.pending_claims[claim_hash].name
claim_info = self.db.get_claim_txo(claim_hash)
if claim_info:
return claim_info.name
def _get_pending_supported_amount(self, claim_hash: bytes, height: Optional[int] = None) -> int:
amount = self._cached_get_active_amount(claim_hash, ACTIVATED_SUPPORT_TXO_TYPE, height or (self.height + 1))
if claim_hash in self.staged_activated_support:
amount += sum(self.staged_activated_support[claim_hash])
if claim_hash in self.possible_future_activated_support:
amount += sum(self.possible_future_activated_support[claim_hash])
if claim_hash in self.removed_active_support:
return amount - sum(self.removed_active_support[claim_hash])
return amount
def _get_pending_effective_amount(self, name: str, claim_hash: bytes, height: Optional[int] = None) -> int:
claim_amount = self._get_pending_claim_amount(name, claim_hash, height=height)
support_amount = self._get_pending_supported_amount(claim_hash, height=height)
return claim_amount + support_amount
def _get_takeover_ops(self, height: int) -> List['RevertableOp']:
# cache for controlling claims as of the previous block
controlling_claims = {}
def get_controlling(_name):
if _name not in controlling_claims:
_controlling = self.db.get_controlling_claim(_name)
controlling_claims[_name] = _controlling
else:
_controlling = controlling_claims[_name]
return _controlling
ops = []
names_with_abandoned_controlling_claims: List[str] = []
# get the claims and supports previously scheduled to be activated at this block
activated_at_height = self.db.get_activated_at_height(height)
activate_in_future = defaultdict(lambda: defaultdict(list))
future_activations = defaultdict(dict)
def get_delayed_activate_ops(name: str, claim_hash: bytes, is_new_claim: bool, tx_num: int, nout: int,
amount: int, is_support: bool) -> List['RevertableOp']:
controlling = get_controlling(name)
nothing_is_controlling = not controlling
staged_is_controlling = False if not controlling else claim_hash == controlling.claim_hash
controlling_is_abandoned = False if not controlling else \
controlling.claim_hash in names_with_abandoned_controlling_claims
if nothing_is_controlling or staged_is_controlling or controlling_is_abandoned:
delay = 0
elif is_new_claim:
delay = self.coin.get_delay_for_name(height - controlling.height)
else:
controlling_effective_amount = self._get_pending_effective_amount(name, controlling.claim_hash)
staged_effective_amount = self._get_pending_effective_amount(name, claim_hash)
staged_update_could_cause_takeover = staged_effective_amount > controlling_effective_amount
delay = 0 if not staged_update_could_cause_takeover else self.coin.get_delay_for_name(
height - controlling.height
)
if delay == 0: # if delay was 0 it needs to be considered for takeovers
activated_at_height[PendingActivationValue(claim_hash, name)].append(
PendingActivationKey(
height, ACTIVATED_SUPPORT_TXO_TYPE if is_support else ACTIVATED_CLAIM_TXO_TYPE, tx_num, nout
)
)
else: # if the delay was higher if still needs to be considered if something else triggers a takeover
activate_in_future[name][claim_hash].append((
PendingActivationKey(
height + delay, ACTIVATED_SUPPORT_TXO_TYPE if is_support else ACTIVATED_CLAIM_TXO_TYPE,
tx_num, nout
), amount
))
if is_support:
self.possible_future_support_txos[claim_hash].append((tx_num, nout))
return StagedActivation(
ACTIVATED_SUPPORT_TXO_TYPE if is_support else ACTIVATED_CLAIM_TXO_TYPE, claim_hash, tx_num, nout,
height + delay, name, amount
).get_activate_ops()
# determine names needing takeover/deletion due to controlling claims being abandoned
# and add ops to deactivate abandoned claims
for claim_hash, staged in self.staged_pending_abandoned.items():
controlling = get_controlling(staged.name)
if controlling and controlling.claim_hash == claim_hash:
names_with_abandoned_controlling_claims.append(staged.name)
# print(f"\t{staged.name} needs takeover")
activation = self.db.get_activation(staged.tx_num, staged.position)
if activation > 0: # db returns -1 for non-existent txos
# removed queued future activation from the db
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, staged.claim_hash, staged.tx_num, staged.position,
activation, staged.name, staged.amount
).get_remove_activate_ops()
)
else:
# it hadn't yet been activated
pass
# get the removed activated supports for controlling claims to determine if takeovers are possible
abandoned_support_check_need_takeover = defaultdict(list)
for claim_hash, amounts in self.removed_active_support.items():
name = self._get_pending_claim_name(claim_hash)
if name is None:
continue
controlling = get_controlling(name)
if controlling and controlling.claim_hash == claim_hash and \
name not in names_with_abandoned_controlling_claims:
abandoned_support_check_need_takeover[(name, claim_hash)].extend(amounts)
# prepare to activate or delay activation of the pending claims being added this block
for (tx_num, nout), staged in self.pending_claims.items():
ops.extend(get_delayed_activate_ops(
staged.name, staged.claim_hash, not staged.is_update, tx_num, nout, staged.amount, is_support=False
))
# and the supports
for (tx_num, nout), (claim_hash, amount) in self.pending_support_txos.items():
if claim_hash in self.staged_pending_abandoned:
continue
elif claim_hash in self.pending_claim_txos:
name = self.pending_claims[self.pending_claim_txos[claim_hash]].name
staged_is_new_claim = not self.pending_claims[self.pending_claim_txos[claim_hash]].is_update
else:
supported_claim_info = self.db.get_claim_txo(claim_hash)
if not supported_claim_info:
# the supported claim doesn't exist
continue
else:
v = supported_claim_info
name = v.name
staged_is_new_claim = (v.root_tx_num, v.root_position) == (v.tx_num, v.position)
ops.extend(get_delayed_activate_ops(
name, claim_hash, staged_is_new_claim, tx_num, nout, amount, is_support=True
))
# add the activation/delayed-activation ops
for activated, activated_txos in activated_at_height.items():
controlling = get_controlling(activated.name)
if activated.claim_hash in self.staged_pending_abandoned:
continue
reactivate = False
if not controlling or controlling.claim_hash == activated.claim_hash:
# there is no delay for claims to a name without a controlling value or to the controlling value
reactivate = True
for activated_txo in activated_txos:
if activated_txo.is_support and (activated_txo.tx_num, activated_txo.position) in \
self.pending_removed_support[activated.name][activated.claim_hash]:
# print("\tskip activate support for pending abandoned claim")
continue
if activated_txo.is_claim:
txo_type = ACTIVATED_CLAIM_TXO_TYPE
txo_tup = (activated_txo.tx_num, activated_txo.position)
if txo_tup in self.pending_claims:
amount = self.pending_claims[txo_tup].amount
else:
amount = self.db.get_claim_txo_amount(
activated.claim_hash
)
self.staged_activated_claim[(activated.name, activated.claim_hash)] = amount
else:
txo_type = ACTIVATED_SUPPORT_TXO_TYPE
txo_tup = (activated_txo.tx_num, activated_txo.position)
if txo_tup in self.pending_support_txos:
amount = self.pending_support_txos[txo_tup][1]
else:
amount = self.db.get_support_txo_amount(
activated.claim_hash, activated_txo.tx_num, activated_txo.position
)
if amount is None:
# print("\tskip activate support for non existent claim")
continue
self.staged_activated_support[activated.claim_hash].append(amount)
self.pending_activated[activated.name][activated.claim_hash].append((activated_txo, amount))
# print(f"\tactivate {'support' if txo_type == ACTIVATED_SUPPORT_TXO_TYPE else 'claim'} "
# f"{activated.claim_hash.hex()} @ {activated_txo.height}")
if reactivate:
ops.extend(
StagedActivation(
txo_type, activated.claim_hash, activated_txo.tx_num, activated_txo.position,
activated_txo.height, activated.name, amount
).get_activate_ops()
)
# go through claims where the controlling claim or supports to the controlling claim have been abandoned
# check if takeovers are needed or if the name node is now empty
need_reactivate_if_takes_over = {}
for need_takeover in names_with_abandoned_controlling_claims:
existing = self.db.get_claim_txos_for_name(need_takeover)
has_candidate = False
# add existing claims to the queue for the takeover
# track that we need to reactivate these if one of them becomes controlling
for candidate_claim_hash, (tx_num, nout) in existing.items():
if candidate_claim_hash in self.staged_pending_abandoned:
continue
has_candidate = True
existing_activation = self.db.get_activation(tx_num, nout)
activate_key = PendingActivationKey(
existing_activation, ACTIVATED_CLAIM_TXO_TYPE, tx_num, nout
)
self.pending_activated[need_takeover][candidate_claim_hash].append((
activate_key, self.db.get_claim_txo_amount(candidate_claim_hash)
))
need_reactivate_if_takes_over[(need_takeover, candidate_claim_hash)] = activate_key
# print(f"\tcandidate to takeover abandoned controlling claim for "
# f"{activate_key.tx_num}:{activate_key.position} {activate_key.is_claim}")
if not has_candidate:
# remove name takeover entry, the name is now unclaimed
controlling = get_controlling(need_takeover)
ops.extend(get_remove_name_ops(need_takeover, controlling.claim_hash, controlling.height))
# scan for possible takeovers out of the accumulated activations, of these make sure there
# aren't any future activations for the taken over names with yet higher amounts, if there are
# these need to get activated now and take over instead. for example:
# claim A is winning for 0.1 for long enough for a > 1 takeover delay
# claim B is made for 0.2
# a block later, claim C is made for 0.3, it will schedule to activate 1 (or rarely 2) block(s) after B
# upon the delayed activation of B, we need to detect to activate C and make it take over early instead
claim_exists = {}
for activated, activated_txos in self.db.get_future_activated(height).items():
# uses the pending effective amount for the future activation height, not the current height
future_amount = self._get_pending_claim_amount(
activated.name, activated.claim_hash, activated_txos[-1].height + 1
)
if activated.claim_hash not in claim_exists:
claim_exists[activated.claim_hash] = activated.claim_hash in self.pending_claim_txos or (
self.db.get_claim_txo(activated.claim_hash) is not None)
if claim_exists[activated.claim_hash] and activated.claim_hash not in self.staged_pending_abandoned:
v = future_amount, activated, activated_txos[-1]
future_activations[activated.name][activated.claim_hash] = v
for name, future_activated in activate_in_future.items():
for claim_hash, activated in future_activated.items():
if claim_hash not in claim_exists:
claim_exists[claim_hash] = claim_hash in self.pending_claim_txos or (
self.db.get_claim_txo(claim_hash) is not None)
if not claim_exists[claim_hash]:
continue
if claim_hash in self.staged_pending_abandoned:
continue
for txo in activated:
v = txo[1], PendingActivationValue(claim_hash, name), txo[0]
future_activations[name][claim_hash] = v
if txo[0].is_claim:
self.possible_future_activated_claim[(name, claim_hash)] = txo[1]
else:
self.possible_future_activated_support[claim_hash].append(txo[1])
# process takeovers
checked_names = set()
for name, activated in self.pending_activated.items():
checked_names.add(name)
controlling = controlling_claims[name]
amounts = {
claim_hash: self._get_pending_effective_amount(name, claim_hash)
for claim_hash in activated.keys() if claim_hash not in self.staged_pending_abandoned
}
# if there is a controlling claim include it in the amounts to ensure it remains the max
if controlling and controlling.claim_hash not in self.staged_pending_abandoned:
amounts[controlling.claim_hash] = self._get_pending_effective_amount(name, controlling.claim_hash)
winning_claim_hash = max(amounts, key=lambda x: amounts[x])
if not controlling or (winning_claim_hash != controlling.claim_hash and
name in names_with_abandoned_controlling_claims) or \
((winning_claim_hash != controlling.claim_hash) and (amounts[winning_claim_hash] > amounts[controlling.claim_hash])):
amounts_with_future_activations = {claim_hash: amount for claim_hash, amount in amounts.items()}
amounts_with_future_activations.update(
{
claim_hash: self._get_pending_effective_amount(
name, claim_hash, self.height + 1 + self.coin.maxTakeoverDelay
) for claim_hash in future_activations[name]
}
)
winning_including_future_activations = max(
amounts_with_future_activations, key=lambda x: amounts_with_future_activations[x]
)
future_winning_amount = amounts_with_future_activations[winning_including_future_activations]
if winning_claim_hash != winning_including_future_activations and \
future_winning_amount > amounts[winning_claim_hash]:
# print(f"\ttakeover by {winning_claim_hash.hex()} triggered early activation and "
# f"takeover by {winning_including_future_activations.hex()} at {height}")
# handle a pending activated claim jumping the takeover delay when another name takes over
if winning_including_future_activations not in self.pending_claim_txos:
claim = self.db.get_claim_txo(winning_including_future_activations)
tx_num = claim.tx_num
position = claim.position
amount = claim.amount
activation = self.db.get_activation(tx_num, position)
else:
tx_num, position = self.pending_claim_txos[winning_including_future_activations]
amount = None
activation = None
for (k, tx_amount) in activate_in_future[name][winning_including_future_activations]:
if (k.tx_num, k.position) == (tx_num, position):
amount = tx_amount
activation = k.height
break
assert None not in (amount, activation)
# update the claim that's activating early
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, winning_including_future_activations, tx_num,
position, activation, name, amount
).get_remove_activate_ops()
)
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, winning_including_future_activations, tx_num,
position, height, name, amount
).get_activate_ops()
)
for (k, amount) in activate_in_future[name][winning_including_future_activations]:
txo = (k.tx_num, k.position)
if txo in self.possible_future_support_txos[winning_including_future_activations]:
t = ACTIVATED_SUPPORT_TXO_TYPE
ops.extend(
StagedActivation(
t, winning_including_future_activations, k.tx_num,
k.position, k.height, name, amount
).get_remove_activate_ops()
)
ops.extend(
StagedActivation(
t, winning_including_future_activations, k.tx_num,
k.position, height, name, amount
).get_activate_ops()
)
ops.extend(get_takeover_name_ops(name, winning_including_future_activations, height, controlling))
elif not controlling or (winning_claim_hash != controlling.claim_hash and
name in names_with_abandoned_controlling_claims) or \
((winning_claim_hash != controlling.claim_hash) and (amounts[winning_claim_hash] > amounts[controlling.claim_hash])):
# print(f"\ttakeover by {winning_claim_hash.hex()} at {height}")
if (name, winning_claim_hash) in need_reactivate_if_takes_over:
previous_pending_activate = need_reactivate_if_takes_over[(name, winning_claim_hash)]
amount = self.db.get_claim_txo_amount(
winning_claim_hash
)
if winning_claim_hash in self.pending_claim_txos:
tx_num, position = self.pending_claim_txos[winning_claim_hash]
amount = self.pending_claims[(tx_num, position)].amount
else:
tx_num, position = previous_pending_activate.tx_num, previous_pending_activate.position
if previous_pending_activate.height > height:
# the claim had a pending activation in the future, move it to now
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, winning_claim_hash, tx_num,
position, previous_pending_activate.height, name, amount
).get_remove_activate_ops()
)
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, winning_claim_hash, tx_num,
position, height, name, amount
).get_activate_ops()
)
ops.extend(get_takeover_name_ops(name, winning_claim_hash, height, controlling))
elif winning_claim_hash == controlling.claim_hash:
# print("\tstill winning")
pass
else:
# print("\tno takeover")
pass
# handle remaining takeovers from abandoned supports
for (name, claim_hash), amounts in abandoned_support_check_need_takeover.items():
if name in checked_names:
continue
checked_names.add(name)
controlling = get_controlling(name)
amounts = {
claim_hash: self._get_pending_effective_amount(name, claim_hash)
for claim_hash in self.db.get_claims_for_name(name) if claim_hash not in self.staged_pending_abandoned
}
if controlling and controlling.claim_hash not in self.staged_pending_abandoned:
amounts[controlling.claim_hash] = self._get_pending_effective_amount(name, controlling.claim_hash)
winning = max(amounts, key=lambda x: amounts[x])
if (controlling and winning != controlling.claim_hash) or (not controlling and winning):
# print(f"\ttakeover from abandoned support {controlling.claim_hash.hex()} -> {winning.hex()}")
ops.extend(get_takeover_name_ops(name, winning, height, controlling))
# gather cumulative removed/touched sets to update the search index
self.removed_claims_to_send_es.update(set(self.staged_pending_abandoned.keys()))
self.touched_claims_to_send_es.update(
set(self.staged_activated_support.keys()).union(
set(claim_hash for (_, claim_hash) in self.staged_activated_claim.keys())
).union(self.signatures_changed).difference(self.removed_claims_to_send_es)
)
# use the cumulative changes to update bid ordered resolve
for removed in self.removed_claims_to_send_es:
removed_claim = self.db.get_claim_txo(removed)
if not removed_claim:
continue
ops.extend(get_remove_effective_amount_ops(
removed_claim.name, self._cached_get_effective_amount(removed), removed_claim.tx_num,
removed_claim.position, removed
))
for touched in self.touched_claims_to_send_es:
if touched in self.pending_claim_txos:
pending = self.pending_claims[self.pending_claim_txos[touched]]
name, tx_num, position = pending.name, pending.tx_num, pending.position
claim_from_db = self.db.get_claim_txo(touched)
if claim_from_db:
prev_tx_num, prev_position = claim_from_db.tx_num, claim_from_db.position
ops.extend(get_remove_effective_amount_ops(
name, self._cached_get_effective_amount(touched), prev_tx_num, prev_position, touched
))
else:
v = self.db.get_claim_txo(touched)
name, tx_num, position = v.name, v.tx_num, v.position
ops.extend(get_remove_effective_amount_ops(
name, self._cached_get_effective_amount(touched), tx_num, position, touched
))
ops.extend(get_add_effective_amount_ops(name, self._get_pending_effective_amount(name, touched),
tx_num, position, touched))
return ops
def advance_block(self, block):
height = self.height + 1
# print("advance ", height)
txs: List[Tuple[Tx, bytes]] = block.transactions
block_hash = self.coin.header_hash(block.header)
self.block_hashes.append(block_hash)
self.block_txs.append((b''.join(tx_hash for tx, tx_hash in txs), [tx.raw for tx, _ in txs]))
first_tx_num = self.tx_count
undo_info = []
hashXs_by_tx = []
tx_count = self.tx_count
# Use local vars for speed in the loops
put_utxo = self.utxo_cache.__setitem__
claimtrie_stash = []
claimtrie_stash_extend = claimtrie_stash.extend
spend_utxo = self.spend_utxo
undo_info_append = undo_info.append
update_touched = self.touched.update
append_hashX_by_tx = hashXs_by_tx.append
hashX_from_script = self.coin.hashX_from_script
for tx, tx_hash in txs:
spent_claims = {}
hashXs = [] # hashXs touched by spent inputs/rx outputs
append_hashX = hashXs.append
tx_numb = pack('<I', tx_count)
txos = Transaction(tx.raw).outputs
# Spend the inputs
for txin in tx.inputs:
if txin.is_generation():
continue
# spend utxo for address histories
cache_value = spend_utxo(txin.prev_hash, txin.prev_idx)
undo_info_append(cache_value)
append_hashX(cache_value[:-12])
spend_claim_or_support_ops = self._spend_claim_or_support_txo(txin, spent_claims)
if spend_claim_or_support_ops:
claimtrie_stash_extend(spend_claim_or_support_ops)
# Add the new UTXOs
for nout, txout in enumerate(tx.outputs):
# Get the hashX. Ignore unspendable outputs
hashX = hashX_from_script(txout.pk_script)
if hashX:
append_hashX(hashX)
put_utxo(tx_hash + pack('<H', nout), hashX + tx_numb + pack('<Q', txout.value))
# add claim/support txo
claim_or_support_ops = self._add_claim_or_support(
height, tx_hash, tx_count, nout, txos[nout], spent_claims
)
if claim_or_support_ops:
claimtrie_stash_extend(claim_or_support_ops)
# Handle abandoned claims
abandon_ops = self._abandon(spent_claims)
if abandon_ops:
claimtrie_stash_extend(abandon_ops)
append_hashX_by_tx(hashXs)
update_touched(hashXs)
self.db.total_transactions.append(tx_hash)
self.db.transaction_num_mapping[tx_hash] = tx_count
tx_count += 1
# handle expired claims
expired_ops = self._expire_claims(height)
if expired_ops:
# print(f"************\nexpire claims at block {height}\n************")
claimtrie_stash_extend(expired_ops)
# activate claims and process takeovers
takeover_ops = self._get_takeover_ops(height)
if takeover_ops:
claimtrie_stash_extend(takeover_ops)
# self.db.add_unflushed(hashXs_by_tx, self.tx_count)
_unflushed = self.db.hist_unflushed
_count = 0
for _tx_num, _hashXs in enumerate(hashXs_by_tx, start=first_tx_num):
for _hashX in set(_hashXs):
_unflushed[_hashX].append(_tx_num)
_count += len(_hashXs)
self.db.hist_unflushed_count += _count
self.tx_count = tx_count
self.db.tx_counts.append(self.tx_count)
undo_claims = b''.join(op.invert().pack() for op in claimtrie_stash)
self.claimtrie_stash.extend(claimtrie_stash)
# print("%i undo bytes for %i (%i claimtrie stash ops)" % (len(undo_claims), height, len(claimtrie_stash)))
if height >= self.daemon.cached_height() - self.env.reorg_limit:
self.undo_infos.append((undo_info, height))
self.undo_claims.append((undo_claims, height))
self.db.write_raw_block(block.raw, height)
self.height = height
self.headers.append(block.header)
self.tip = self.coin.header_hash(block.header)
self.db.flush_dbs(self.flush_data())
self.pending_claims.clear()
self.pending_claim_txos.clear()
self.pending_supports.clear()
self.pending_support_txos.clear()
self.pending_removed_support.clear()
self.staged_pending_abandoned.clear()
self.removed_active_support.clear()
self.staged_activated_support.clear()
self.staged_activated_claim.clear()
self.pending_activated.clear()
self.possible_future_activated_claim.clear()
self.possible_future_activated_support.clear()
self.possible_future_support_txos.clear()
self.pending_channels.clear()
self.amount_cache.clear()
self.signatures_changed.clear()
# for cache in self.search_cache.values():
# cache.clear()
self.history_cache.clear()
self.notifications.notified_mempool_txs.clear()
def backup_blocks(self, raw_blocks):
"""Backup the raw blocks and flush.
The blocks should be in order of decreasing height, starting at.
self.height. A flush is performed once the blocks are backed up.
"""
self.db.assert_flushed(self.flush_data())
assert self.height >= len(raw_blocks)
coin = self.coin
for raw_block in raw_blocks:
self.logger.info("backup block %i", self.height)
# Check and update self.tip
block = coin.block(raw_block, self.height)
header_hash = coin.header_hash(block.header)
if header_hash != self.tip:
raise ChainError('backup block {} not tip {} at height {:,d}'
.format(hash_to_hex_str(header_hash),
hash_to_hex_str(self.tip),
self.height))
self.tip = coin.header_prevhash(block.header)
self.backup_txs(block.transactions)
self.height -= 1
self.db.tx_counts.pop()
# self.touched can include other addresses which is
# harmless, but remove None.
self.touched.discard(None)
self.db.flush_backup(self.flush_data(), self.touched)
self.logger.info(f'backed up to height {self.height:,d}')
def backup_txs(self, txs):
# Prevout values, in order down the block (coinbase first if present)
# undo_info is in reverse block order
undo_info, undo_claims = self.db.read_undo_info(self.height)
if undo_info is None:
raise ChainError(f'no undo information found for height {self.height:,d}')
n = len(undo_info)
# Use local vars for speed in the loops
s_pack = pack
undo_entry_len = 12 + HASHX_LEN
for tx, tx_hash in reversed(txs):
for idx, txout in enumerate(tx.outputs):
# Spend the TX outputs. Be careful with unspendable
# outputs - we didn't save those in the first place.
hashX = self.coin.hashX_from_script(txout.pk_script)
if hashX:
cache_value = self.spend_utxo(tx_hash, idx)
self.touched.add(cache_value[:-12])
# Restore the inputs
for txin in reversed(tx.inputs):
if txin.is_generation():
continue
n -= undo_entry_len
undo_item = undo_info[n:n + undo_entry_len]
self.utxo_cache[txin.prev_hash + s_pack('<H', txin.prev_idx)] = undo_item
self.touched.add(undo_item[:-12])
self.db.transaction_num_mapping.pop(self.db.total_transactions.pop())
assert n == 0
self.tx_count -= len(txs)
self.undo_claims.append((undo_claims, self.height))
"""An in-memory UTXO cache, representing all changes to UTXO state
since the last DB flush.
We want to store millions of these in memory for optimal
performance during initial sync, because then it is possible to
spend UTXOs without ever going to the database (other than as an
entry in the address history, and there is only one such entry per
TX not per UTXO). So store them in a Python dictionary with
binary keys and values.
Key: TX_HASH + TX_IDX (32 + 2 = 34 bytes)
Value: HASHX + TX_NUM + VALUE (11 + 4 + 8 = 23 bytes)
That's 57 bytes of raw data in-memory. Python dictionary overhead
means each entry actually uses about 205 bytes of memory. So
almost 5 million UTXOs can fit in 1GB of RAM. There are
approximately 42 million UTXOs on bitcoin mainnet at height
433,000.
Semantics:
add: Add it to the cache dictionary.
spend: Remove it if in the cache dictionary. Otherwise it's
been flushed to the DB. Each UTXO is responsible for two
entries in the DB. Mark them for deletion in the next
cache flush.
The UTXO database format has to be able to do two things efficiently:
1. Given an address be able to list its UTXOs and their values
so its balance can be efficiently computed.
2. When processing transactions, for each prevout spent - a (tx_hash,
idx) pair - we have to be able to remove it from the DB. To send
notifications to clients we also need to know any address it paid
to.
To this end we maintain two "tables", one for each point above:
1. Key: b'u' + address_hashX + tx_idx + tx_num
Value: the UTXO value as a 64-bit unsigned integer
2. Key: b'h' + compressed_tx_hash + tx_idx + tx_num
Value: hashX
The compressed tx hash is just the first few bytes of the hash of
the tx in which the UTXO was created. As this is not unique there
will be potential collisions so tx_num is also in the key. When
looking up a UTXO the prefix space of the compressed hash needs to
be searched and resolved if necessary with the tx_num. The
collision rate is low (<0.1%).
"""
def spend_utxo(self, tx_hash, tx_idx):
"""Spend a UTXO and return the 33-byte value.
If the UTXO is not in the cache it must be on disk. We store
all UTXOs so not finding one indicates a logic error or DB
corruption.
"""
# Fast track is it being in the cache
idx_packed = pack('<H', tx_idx)
cache_value = self.utxo_cache.pop(tx_hash + idx_packed, None)
if cache_value:
return cache_value
# Spend it from the DB.
# Key: b'h' + compressed_tx_hash + tx_idx + tx_num
# Value: hashX
prefix = DB_PREFIXES.HASHX_UTXO_PREFIX.value + tx_hash[:4] + idx_packed
candidates = {db_key: hashX for db_key, hashX in self.db.db.iterator(prefix=prefix)}
for hdb_key, hashX in candidates.items():
tx_num_packed = hdb_key[-4:]
if len(candidates) > 1:
tx_num, = unpack('<I', tx_num_packed)
try:
hash, height = self.db.fs_tx_hash(tx_num)
except IndexError:
self.logger.error("data integrity error for hashx history: %s missing tx #%s (%s:%s)",
hashX.hex(), tx_num, hash_to_hex_str(tx_hash), tx_idx)
continue
if hash != tx_hash:
assert hash is not None # Should always be found
continue
# Key: b'u' + address_hashX + tx_idx + tx_num
# Value: the UTXO value as a 64-bit unsigned integer
udb_key = DB_PREFIXES.UTXO_PREFIX.value + hashX + hdb_key[-6:]
utxo_value_packed = self.db.db.get(udb_key)
if utxo_value_packed is None:
self.logger.warning(
"%s:%s is not found in UTXO db for %s", hash_to_hex_str(tx_hash), tx_idx, hash_to_hex_str(hashX)
)
raise ChainError(f"{hash_to_hex_str(tx_hash)}:{tx_idx} is not found in UTXO db for {hash_to_hex_str(hashX)}")
# Remove both entries for this UTXO
self.db_deletes.append(hdb_key)
self.db_deletes.append(udb_key)
return hashX + tx_num_packed + utxo_value_packed
self.logger.error('UTXO {hash_to_hex_str(tx_hash)} / {tx_idx} not found in "h" table')
raise ChainError('UTXO {} / {:,d} not found in "h" table'
.format(hash_to_hex_str(tx_hash), tx_idx))
async def _process_prefetched_blocks(self):
"""Loop forever processing blocks as they arrive."""
while True:
if self.height == self.daemon.cached_height():
if not self._caught_up_event.is_set():
await self._first_caught_up()
self._caught_up_event.set()
await self.blocks_event.wait()
self.blocks_event.clear()
if self.reorg_count: # this could only happen by calling the reorg rpc
await self.reorg_chain(self.reorg_count)
self.reorg_count = 0
else:
blocks = self.prefetcher.get_prefetched_blocks()
try:
await self.check_and_advance_blocks(blocks)
except Exception:
self.logger.exception("error while processing txs")
raise
async def _first_caught_up(self):
self.logger.info(f'caught up to height {self.height}')
# Flush everything but with first_sync->False state.
first_sync = self.db.first_sync
self.db.first_sync = False
await self.flush(True)
if first_sync:
self.logger.info(f'{lbry.__version__} synced to '
f'height {self.height:,d}')
# Reopen for serving
await self.db.open_dbs()
# --- External API
async def fetch_and_process_blocks(self, caught_up_event):
"""Fetch, process and index blocks from the daemon.
Sets caught_up_event when first caught up. Flushes to disk
and shuts down cleanly if cancelled.
This is mainly because if, during initial sync ElectrumX is
asked to shut down when a large number of blocks have been
processed but not written to disk, it should write those to
disk before exiting, as otherwise a significant amount of work
could be lost.
"""
self._caught_up_event = caught_up_event
try:
await self.db.open_dbs()
self.height = self.db.db_height
self.tip = self.db.db_tip
self.tx_count = self.db.db_tx_count
self.status_server.set_height(self.db.fs_height, self.db.db_tip)
await asyncio.wait([
self.prefetcher.main_loop(self.height),
self._process_prefetched_blocks()
])
except asyncio.CancelledError:
raise
except:
self.logger.exception("Block processing failed!")
raise
finally:
self.status_server.stop()
# Shut down block processing
self.logger.info('flushing to DB for a clean shutdown...')
await self.flush(True)
self.db.close()
self.executor.shutdown(wait=True)
def force_chain_reorg(self, count):
"""Force a reorg of the given number of blocks.
Returns True if a reorg is queued, false if not caught up.
"""
if self._caught_up_event.is_set():
self.reorg_count = count
self.blocks_event.set()
return True
return False
class Timer:
def __init__(self, name):
self.name = name
self.total = 0
self.count = 0
self.sub_timers = {}
self._last_start = None
def add_timer(self, name):
if name not in self.sub_timers:
self.sub_timers[name] = Timer(name)
return self.sub_timers[name]
def run(self, func, *args, forward_timer=False, timer_name=None, **kwargs):
t = self.add_timer(timer_name or func.__name__)
t.start()
try:
if forward_timer:
return func(*args, **kwargs, timer=t)
else:
return func(*args, **kwargs)
finally:
t.stop()
def start(self):
self._last_start = time.time()
return self
def stop(self):
self.total += (time.time() - self._last_start)
self.count += 1
self._last_start = None
return self
def show(self, depth=0, height=None):
if depth == 0:
print('='*100)
if height is not None:
print(f'STATISTICS AT HEIGHT {height}')
print('='*100)
else:
print(
f"{' '*depth} {self.total/60:4.2f}mins {self.name}"
# f"{self.total/self.count:.5f}sec/call, "
)
for sub_timer in self.sub_timers.values():
sub_timer.show(depth+1)
if depth == 0:
print('='*100)