lbry-sdk/lbry/wallet/server/block_processor.py
2021-10-05 16:44:49 -04:00

1276 lines
57 KiB
Python

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.wallet.transaction import OutputScript, Output
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
from lbry.wallet.server.db.claimtrie import get_remove_name_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
from lbry.wallet.server.udp import StatusServer
if typing.TYPE_CHECKING:
from lbry.wallet.server.leveldb import LevelDB
from lbry.wallet.server.db.revertable import RevertableOp
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
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()
self.pending_claims: typing.Dict[Tuple[int, int], StagedClaimtrieItem] = {}
self.pending_claim_txos: typing.Dict[bytes, Tuple[int, int]] = {}
self.pending_supports = defaultdict(list)
self.pending_support_txos = {}
self.pending_removed_support = defaultdict(lambda: defaultdict(list))
self.staged_pending_abandoned: Dict[bytes, StagedClaimtrieItem] = {}
self.removed_active_support = defaultdict(list)
self.staged_activated_support = defaultdict(list)
self.staged_activated_claim = {}
self.pending_activated = defaultdict(lambda: defaultdict(list))
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:
await self.run_in_thread_with_lock(self.advance_block, block)
print("******************\n")
except:
self.logger.exception("advance blocks failed")
raise
# if self.sql:
# await self.db.search_index.claim_consumer(self.db.claim_producer())
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 lbry://{claim_name}#{claim_hash.hex()} ({tx_num} {txo.amount})")
else:
claim_hash = txo.claim_hash[::-1]
print(f"\tupdate lbry://{claim_name}#{claim_hash.hex()} ({tx_num} {txo.amount})")
try:
signable = txo.signable
except: # google.protobuf.message.DecodeError: Could not parse JSON.
signable = None
ops = []
signing_channel_hash = None
if signable and signable.signing_channel_hash:
signing_channel_hash = txo.signable.signing_channel_hash[::-1]
if txo.script.is_claim_name:
root_tx_num, root_idx = tx_num, nout
else:
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 lbry://{claim_name}#{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:
k, 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, signing_channel_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 lbry://{supported_name}#{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)
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)
self.removed_active_support[spent_support].append(support_amount)
print(f"\tspent support for lbry://{supported_name}#{spent_support.hex()} activation:{activation} {support_amount}")
return StagedClaimtrieSupport(
spent_support, txin_num, txin.prev_idx, support_amount
).get_spend_support_txo_ops() + StagedActivation(
ACTIVATED_SUPPORT_TXO_TYPE, spent_support, txin_num, txin.prev_idx, activation, supported_name,
support_amount
).get_remove_activate_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)
k, v = self.db.get_claim_txo(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, signing_hash
)
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
expiration = self.coin.get_expiration_height(self.height)
else:
k, 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
prev_signing_hash = self.db.get_channel_for_claim(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, prev_signing_hash
)
self.pending_supports[claim_hash].clear()
self.pending_supports.pop(claim_hash)
return staged.get_abandon_ops(self.db.db)
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 lbry://{name}#{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 _get_pending_claim_amount(self, name: str, claim_hash: bytes) -> int:
if (name, claim_hash) in self.staged_activated_claim:
return self.staged_activated_claim[(name, claim_hash)]
return self.db._get_active_amount(claim_hash, ACTIVATED_CLAIM_TXO_TYPE, 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[1].name
def _get_pending_supported_amount(self, claim_hash: bytes) -> int:
support_amount = self.db._get_active_amount(claim_hash, ACTIVATED_SUPPORT_TXO_TYPE, self.height + 1) or 0
amount = support_amount + sum(
self.staged_activated_support.get(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) -> int:
claim_amount = self._get_pending_claim_amount(name, claim_hash)
support_amount = self._get_pending_supported_amount(claim_hash)
return claim_amount + support_amount
def _get_takeover_ops(self, height: int) -> List['RevertableOp']:
ops = []
# get takeovers from claims activated at this block
activated_at_height = self.db.get_activated_at_height(height)
controlling_claims = {}
abandoned_need_takeover = []
abandoned_support_check_need_takeover = defaultdict(list)
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
# 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:
abandoned_need_takeover.append(staged.name)
print(f"\t{staged.name} needs takeover")
activation = self.db.get_activation(staged.tx_num, staged.position)
if activation > 0:
# 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, db returns -1 for non-existent txos
pass
# build set of controlling claims that had activated supports spent to check them for takeovers later
for claim_hash, amounts in self.removed_active_support.items():
name = self._get_pending_claim_name(claim_hash)
controlling = get_controlling(name)
if controlling and controlling.claim_hash == claim_hash and name not in abandoned_need_takeover:
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():
controlling = get_controlling(staged.name)
delay = 0
if not controlling or staged.claim_hash == controlling.claim_hash or \
controlling.claim_hash in abandoned_need_takeover:
pass
else:
controlling_effective_amount = self._get_pending_effective_amount(staged.name, controlling.claim_hash)
amount = self._get_pending_effective_amount(staged.name, staged.claim_hash)
delay = 0
# if this is an OP_CLAIM or the amount appears to trigger a takeover, delay
if not staged.is_update or (amount > controlling_effective_amount):
delay = self.coin.get_delay_for_name(height - controlling.height)
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, staged.claim_hash, staged.tx_num, staged.position,
height + delay, staged.name, staged.amount
).get_activate_ops()
)
if delay == 0: # if delay was 0 it needs to be considered for takeovers
activated_at_height[PendingActivationValue(staged.claim_hash, staged.name)].append(
PendingActivationKey(height, ACTIVATED_CLAIM_TXO_TYPE, tx_num, nout)
)
# 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
is_update = self.pending_claims[self.pending_claim_txos[claim_hash]].is_update
else:
k, v = self.db.get_claim_txo(claim_hash)
name = v.name
is_update = (v.root_tx_num, v.root_position) != (k.tx_num, k.position)
controlling = get_controlling(name)
delay = 0
if not controlling or claim_hash == controlling.claim_hash:
pass
elif not is_update or self._get_pending_effective_amount(staged.name,
claim_hash) > self._get_pending_effective_amount(staged.name, controlling.claim_hash):
delay = self.coin.get_delay_for_name(height - controlling.height)
if delay == 0:
activated_at_height[PendingActivationValue(claim_hash, name)].append(
PendingActivationKey(height + delay, ACTIVATED_SUPPORT_TXO_TYPE, tx_num, nout)
)
ops.extend(
StagedActivation(
ACTIVATED_SUPPORT_TXO_TYPE, claim_hash, tx_num, nout,
height + delay, name, amount
).get_activate_ops()
)
# 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, activated_txo.tx_num, activated_txo.position
)
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
)
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"lbry://{activated.name}#{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 abandoned_need_takeover:
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, tx_num, nout)
))
need_reactivate_if_takes_over[(need_takeover, candidate_claim_hash)] = activate_key
print(f"\tcandidate to takeover abandoned controlling claim for lbry://{need_takeover} - "
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))
# process takeovers from the combined newly added and previously scheduled claims
checked_names = set()
for name, activated in self.pending_activated.items():
checked_names.add(name)
if name in abandoned_need_takeover:
print(f'\tabandoned {name} need takeover')
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 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 not controlling or (winning != controlling.claim_hash and name in abandoned_need_takeover) or ((winning != controlling.claim_hash) and
(amounts[winning] > amounts[controlling.claim_hash])):
if (name, winning) in need_reactivate_if_takes_over:
previous_pending_activate = need_reactivate_if_takes_over[(name, winning)]
amount = self.db.get_claim_txo_amount(
winning, previous_pending_activate.tx_num, previous_pending_activate.position
)
if winning in self.pending_claim_txos:
tx_num, position = self.pending_claim_txos[winning]
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, tx_num,
position, previous_pending_activate.height, name, amount
).get_remove_activate_ops()
)
ops.extend(
StagedActivation(
ACTIVATED_CLAIM_TXO_TYPE, winning, tx_num,
position, height, name, amount
).get_activate_ops()
)
ops.extend(get_takeover_name_ops(name, winning, height))
else:
ops.extend(get_takeover_name_ops(name, winning, height))
elif winning == 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))
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
zero_delay_claims: typing.Dict[Tuple[str, bytes], Tuple[int, int]] = {}
abandoned_or_expired_controlling = set()
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)
# 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
script = OutputScript(txout.pk_script)
script.parse()
claim_or_support_ops = self._add_claim_or_support(
height, tx_hash, tx_count, nout, Output(txout.value, script), 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.effective_amount_changes.clear()
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()
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_for_serving()
async def _first_open_dbs(self):
await self.db.open_for_sync()
self.height = self.db.db_height
self.tip = self.db.db_tip
self.tx_count = self.db.db_tx_count
# --- 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._first_open_dbs()
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)