hub/scribe/blockchain/daemon.py
Jack Robison dfef80d9c2
initial
2022-03-08 12:41:51 -05:00

328 lines
13 KiB
Python

import asyncio
import itertools
import json
import time
import logging
from functools import wraps
import aiohttp
from prometheus_client import Gauge, Histogram
from scribe import PROMETHEUS_NAMESPACE
from scribe.common import LRUCacheWithMetrics, RPCError, DaemonError, WarmingUpError, WorkQueueFullError
log = logging.getLogger(__name__)
NAMESPACE = f"{PROMETHEUS_NAMESPACE}_blockchain"
METHOD_NOT_FOUND = -32601
def handles_errors(decorated_function):
@wraps(decorated_function)
async def wrapper(*args, **kwargs):
try:
return await decorated_function(*args, **kwargs)
except DaemonError as daemon_error:
raise RPCError(1, daemon_error.args[0])
return wrapper
class LBCDaemon:
"""Handles connections to a daemon at the given URL."""
WARMING_UP = -28
id_counter = itertools.count()
lbrycrd_request_time_metric = Histogram(
"lbrycrd_request", "lbrycrd requests count", namespace=NAMESPACE, labelnames=("method",)
)
lbrycrd_pending_count_metric = Gauge(
"lbrycrd_pending_count", "Number of lbrycrd rpcs that are in flight", namespace=NAMESPACE,
labelnames=("method",)
)
def __init__(self, coin, url, max_workqueue=10, init_retry=0.25,
max_retry=4.0):
self.coin = coin
self.logger = logging.getLogger(__name__)
self.set_url(url)
# Limit concurrent RPC calls to this number.
# See DEFAULT_HTTP_WORKQUEUE in bitcoind, which is typically 16
self.workqueue_semaphore = asyncio.Semaphore(value=max_workqueue)
self.init_retry = init_retry
self.max_retry = max_retry
self._height = None
self.available_rpcs = {}
self.connector = aiohttp.TCPConnector(ssl=False)
self._block_hash_cache = LRUCacheWithMetrics(100000)
self._block_cache = LRUCacheWithMetrics(2 ** 13, metric_name='block', namespace=NAMESPACE)
async def close(self):
if self.connector:
await self.connector.close()
self.connector = None
def set_url(self, url):
"""Set the URLS to the given list, and switch to the first one."""
urls = url.split(',')
urls = [self.coin.sanitize_url(url) for url in urls]
for n, url in enumerate(urls):
status = '' if n else ' (current)'
logged_url = self.logged_url(url)
self.logger.info(f'daemon #{n + 1} at {logged_url}{status}')
self.url_index = 0
self.urls = urls
def current_url(self):
"""Returns the current daemon URL."""
return self.urls[self.url_index]
def logged_url(self, url=None):
"""The host and port part, for logging."""
url = url or self.current_url()
return url[url.rindex('@') + 1:]
def failover(self):
"""Call to fail-over to the next daemon URL.
Returns False if there is only one, otherwise True.
"""
if len(self.urls) > 1:
self.url_index = (self.url_index + 1) % len(self.urls)
self.logger.info(f'failing over to {self.logged_url()}')
return True
return False
def client_session(self):
"""An aiohttp client session."""
return aiohttp.ClientSession(connector=self.connector, connector_owner=False)
async def _send_data(self, data):
if not self.connector:
raise asyncio.CancelledError('Tried to send request during shutdown.')
async with self.workqueue_semaphore:
async with self.client_session() as session:
async with session.post(self.current_url(), data=data) as resp:
kind = resp.headers.get('Content-Type', None)
if kind == 'application/json':
return await resp.json()
# bitcoind's HTTP protocol "handling" is a bad joke
text = await resp.text()
if 'Work queue depth exceeded' in text:
raise WorkQueueFullError
text = text.strip() or resp.reason
self.logger.error(text)
raise DaemonError(text)
async def _send(self, payload, processor):
"""Send a payload to be converted to JSON.
Handles temporary connection issues. Daemon response errors
are raise through DaemonError.
"""
def log_error(error):
nonlocal last_error_log, retry
now = time.time()
if now - last_error_log > 60:
last_error_log = now
self.logger.error(f'{error} Retrying occasionally...')
if retry == self.max_retry and self.failover():
retry = 0
on_good_message = None
last_error_log = 0
data = json.dumps(payload)
retry = self.init_retry
methods = tuple(
[payload['method']] if isinstance(payload, dict) else [request['method'] for request in payload]
)
while True:
try:
for method in methods:
self.lbrycrd_pending_count_metric.labels(method=method).inc()
result = await self._send_data(data)
result = processor(result)
if on_good_message:
self.logger.info(on_good_message)
return result
except asyncio.TimeoutError:
log_error('timeout error.')
except aiohttp.ServerDisconnectedError:
log_error('disconnected.')
on_good_message = 'connection restored'
except aiohttp.ClientConnectionError:
log_error('connection problem - is your daemon running?')
on_good_message = 'connection restored'
except aiohttp.ClientError as e:
log_error(f'daemon error: {e}')
on_good_message = 'running normally'
except WarmingUpError:
log_error('starting up checking blocks.')
on_good_message = 'running normally'
except WorkQueueFullError:
log_error('work queue full.')
on_good_message = 'running normally'
finally:
for method in methods:
self.lbrycrd_pending_count_metric.labels(method=method).dec()
await asyncio.sleep(retry)
retry = max(min(self.max_retry, retry * 2), self.init_retry)
async def _send_single(self, method, params=None):
"""Send a single request to the daemon."""
start = time.perf_counter()
def processor(result):
err = result['error']
if not err:
return result['result']
if err.get('code') == self.WARMING_UP:
raise WarmingUpError
raise DaemonError(err)
payload = {'method': method, 'id': next(self.id_counter)}
if params:
payload['params'] = params
result = await self._send(payload, processor)
self.lbrycrd_request_time_metric.labels(method=method).observe(time.perf_counter() - start)
return result
async def _send_vector(self, method, params_iterable, replace_errs=False):
"""Send several requests of the same method.
The result will be an array of the same length as params_iterable.
If replace_errs is true, any item with an error is returned as None,
otherwise an exception is raised."""
start = time.perf_counter()
def processor(result):
errs = [item['error'] for item in result if item['error']]
if any(err.get('code') == self.WARMING_UP for err in errs):
raise WarmingUpError
if not errs or replace_errs:
return [item['result'] for item in result]
raise DaemonError(errs)
payload = [{'method': method, 'params': p, 'id': next(self.id_counter)}
for p in params_iterable]
result = []
if payload:
result = await self._send(payload, processor)
self.lbrycrd_request_time_metric.labels(method=method).observe(time.perf_counter() - start)
return result
async def _is_rpc_available(self, method):
"""Return whether given RPC method is available in the daemon.
Results are cached and the daemon will generally not be queried with
the same method more than once."""
available = self.available_rpcs.get(method)
if available is None:
available = True
try:
await self._send_single(method)
except DaemonError as e:
err = e.args[0]
error_code = err.get("code")
available = error_code != METHOD_NOT_FOUND
self.available_rpcs[method] = available
return available
async def block_hex_hashes(self, first, count):
"""Return the hex hashes of count block starting at height first."""
if first + count < (self.cached_height() or 0) - 200:
return await self._cached_block_hex_hashes(first, count)
params_iterable = ((h, ) for h in range(first, first + count))
return await self._send_vector('getblockhash', params_iterable)
async def _cached_block_hex_hashes(self, first, count):
"""Return the hex hashes of count block starting at height first."""
cached = self._block_hash_cache.get((first, count))
if cached:
return cached
params_iterable = ((h, ) for h in range(first, first + count))
self._block_hash_cache[(first, count)] = await self._send_vector('getblockhash', params_iterable)
return self._block_hash_cache[(first, count)]
async def deserialised_block(self, hex_hash):
"""Return the deserialised block with the given hex hash."""
if hex_hash not in self._block_cache:
block = await self._send_single('getblock', (hex_hash, 1))
self._block_cache[hex_hash] = block
return block
return self._block_cache[hex_hash]
async def raw_blocks(self, hex_hashes):
"""Return the raw binary blocks with the given hex hashes."""
params_iterable = ((h, 0) for h in hex_hashes)
blocks = await self._send_vector('getblock', params_iterable)
# Convert hex string to bytes
return [bytes.fromhex(block) for block in blocks]
async def mempool_hashes(self):
"""Update our record of the daemon's mempool hashes."""
return await self._send_single('getrawmempool')
async def estimatefee(self, block_count):
"""Return the fee estimate for the block count. Units are whole
currency units per KB, e.g. 0.00000995, or -1 if no estimate
is available.
"""
args = (block_count, )
if await self._is_rpc_available('estimatesmartfee'):
estimate = await self._send_single('estimatesmartfee', args)
return estimate.get('feerate', -1)
return await self._send_single('estimatefee', args)
async def getnetworkinfo(self):
"""Return the result of the 'getnetworkinfo' RPC call."""
return await self._send_single('getnetworkinfo')
async def relayfee(self):
"""The minimum fee a low-priority tx must pay in order to be accepted
to the daemon's memory pool."""
network_info = await self.getnetworkinfo()
return network_info['relayfee']
async def getrawtransactions(self, hex_hashes, replace_errs=True):
"""Return the serialized raw transactions with the given hashes.
Replaces errors with None by default."""
params_iterable = ((hex_hash, 0) for hex_hash in hex_hashes)
txs = await self._send_vector('getrawtransaction', params_iterable,
replace_errs=replace_errs)
# Convert hex strings to bytes
return [bytes.fromhex(tx) if tx else None for tx in txs]
async def broadcast_transaction(self, raw_tx):
"""Broadcast a transaction to the network."""
return await self._send_single('sendrawtransaction', (raw_tx, ))
async def height(self):
"""Query the daemon for its current height."""
self._height = await self._send_single('getblockcount')
return self._height
def cached_height(self):
"""Return the cached daemon height.
If the daemon has not been queried yet this returns None."""
return self._height
@handles_errors
async def getrawtransaction(self, hex_hash, verbose=False):
return await self._send_single('getrawtransaction', (hex_hash, int(verbose)))
@handles_errors
async def getclaimsforname(self, name):
'''Given a name, retrieves all claims matching that name.'''
return await self._send_single('getclaimsforname', (name,))
@handles_errors
async def getbestblockhash(self):
'''Given a name, retrieves all claims matching that name.'''
return await self._send_single('getbestblockhash')