forked from LBRYCommunity/lbry-sdk
540 lines
19 KiB
Python
540 lines
19 KiB
Python
# Copyright (c) 2018, Neil Booth
|
|
#
|
|
# All rights reserved.
|
|
#
|
|
# The MIT License (MIT)
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining
|
|
# a copy of this software and associated documentation files (the
|
|
# "Software"), to deal in the Software without restriction, including
|
|
# without limitation the rights to use, copy, modify, merge, publish,
|
|
# distribute, sublicense, and/or sell copies of the Software, and to
|
|
# permit persons to whom the Software is furnished to do so, subject to
|
|
# the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be
|
|
# included in all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
|
|
__all__ = ('Connector', 'RPCSession', 'MessageSession', 'Server',
|
|
'BatchError')
|
|
|
|
|
|
import asyncio
|
|
from asyncio import Event, CancelledError
|
|
import logging
|
|
import time
|
|
from contextlib import suppress
|
|
|
|
from lbry.wallet.tasks import TaskGroup
|
|
|
|
from .jsonrpc import Request, JSONRPCConnection, JSONRPCv2, JSONRPC, Batch, Notification
|
|
from .jsonrpc import RPCError, ProtocolError
|
|
from .framing import BadMagicError, BadChecksumError, OversizedPayloadError, BitcoinFramer, NewlineFramer
|
|
from .util import Concurrency
|
|
|
|
|
|
class Connector:
|
|
|
|
def __init__(self, session_factory, host=None, port=None, proxy=None,
|
|
**kwargs):
|
|
self.session_factory = session_factory
|
|
self.host = host
|
|
self.port = port
|
|
self.proxy = proxy
|
|
self.loop = kwargs.get('loop', asyncio.get_event_loop())
|
|
self.kwargs = kwargs
|
|
|
|
async def create_connection(self):
|
|
"""Initiate a connection."""
|
|
connector = self.proxy or self.loop
|
|
return await connector.create_connection(
|
|
self.session_factory, self.host, self.port, **self.kwargs)
|
|
|
|
async def __aenter__(self):
|
|
transport, self.protocol = await self.create_connection()
|
|
# By default, do not limit outgoing connections
|
|
self.protocol.bw_limit = 0
|
|
return self.protocol
|
|
|
|
async def __aexit__(self, exc_type, exc_value, traceback):
|
|
await self.protocol.close()
|
|
|
|
|
|
class SessionBase(asyncio.Protocol):
|
|
"""Base class of networking sessions.
|
|
|
|
There is no client / server distinction other than who initiated
|
|
the connection.
|
|
|
|
To initiate a connection to a remote server pass host, port and
|
|
proxy to the constructor, and then call create_connection(). Each
|
|
successful call should have a corresponding call to close().
|
|
|
|
Alternatively if used in a with statement, the connection is made
|
|
on entry to the block, and closed on exit from the block.
|
|
"""
|
|
|
|
max_errors = 10
|
|
|
|
def __init__(self, *, framer=None, loop=None):
|
|
self.framer = framer or self.default_framer()
|
|
self.loop = loop or asyncio.get_event_loop()
|
|
self.logger = logging.getLogger(self.__class__.__name__)
|
|
self.transport = None
|
|
# Set when a connection is made
|
|
self._address = None
|
|
self._proxy_address = None
|
|
# For logger.debug messages
|
|
self.verbosity = 0
|
|
# Cleared when the send socket is full
|
|
self._can_send = Event()
|
|
self._can_send.set()
|
|
self._pm_task = None
|
|
self._task_group = TaskGroup(self.loop)
|
|
# Force-close a connection if a send doesn't succeed in this time
|
|
self.max_send_delay = 60
|
|
# Statistics. The RPC object also keeps its own statistics.
|
|
self.start_time = time.perf_counter()
|
|
self.errors = 0
|
|
self.send_count = 0
|
|
self.send_size = 0
|
|
self.last_send = self.start_time
|
|
self.recv_count = 0
|
|
self.recv_size = 0
|
|
self.last_recv = self.start_time
|
|
self.last_packet_received = self.start_time
|
|
# Bandwidth usage per hour before throttling starts
|
|
self.bw_limit = 2000000
|
|
self.bw_time = self.start_time
|
|
self.bw_charge = 0
|
|
# Concurrency control
|
|
self.max_concurrent = 6
|
|
self._concurrency = Concurrency(self.max_concurrent)
|
|
|
|
async def _update_concurrency(self):
|
|
# A non-positive value means not to limit concurrency
|
|
if self.bw_limit <= 0:
|
|
return
|
|
now = time.perf_counter()
|
|
# Reduce the recorded usage in proportion to the elapsed time
|
|
refund = (now - self.bw_time) * (self.bw_limit / 3600)
|
|
self.bw_charge = max(0, self.bw_charge - int(refund))
|
|
self.bw_time = now
|
|
# Reduce concurrency allocation by 1 for each whole bw_limit used
|
|
throttle = int(self.bw_charge / self.bw_limit)
|
|
target = max(1, self.max_concurrent - throttle)
|
|
current = self._concurrency.max_concurrent
|
|
if target != current:
|
|
self.logger.info(f'changing task concurrency from {current} '
|
|
f'to {target}')
|
|
await self._concurrency.set_max_concurrent(target)
|
|
|
|
def _using_bandwidth(self, size):
|
|
"""Called when sending or receiving size bytes."""
|
|
self.bw_charge += size
|
|
|
|
async def _limited_wait(self, secs):
|
|
try:
|
|
await asyncio.wait_for(self._can_send.wait(), secs)
|
|
except asyncio.TimeoutError:
|
|
self.abort()
|
|
raise asyncio.TimeoutError(f'task timed out after {secs}s')
|
|
|
|
async def _send_message(self, message):
|
|
if not self._can_send.is_set():
|
|
await self._limited_wait(self.max_send_delay)
|
|
if not self.is_closing():
|
|
framed_message = self.framer.frame(message)
|
|
self.send_size += len(framed_message)
|
|
self._using_bandwidth(len(framed_message))
|
|
self.send_count += 1
|
|
self.last_send = time.perf_counter()
|
|
if self.verbosity >= 4:
|
|
self.logger.debug(f'Sending framed message {framed_message}')
|
|
self.transport.write(framed_message)
|
|
|
|
def _bump_errors(self):
|
|
self.errors += 1
|
|
if self.errors >= self.max_errors:
|
|
# Don't await self.close() because that is self-cancelling
|
|
self._close()
|
|
|
|
def _close(self):
|
|
if self.transport:
|
|
self.transport.close()
|
|
|
|
# asyncio framework
|
|
def data_received(self, framed_message):
|
|
"""Called by asyncio when a message comes in."""
|
|
self.last_packet_received = time.perf_counter()
|
|
if self.verbosity >= 4:
|
|
self.logger.debug(f'Received framed message {framed_message}')
|
|
self.recv_size += len(framed_message)
|
|
self._using_bandwidth(len(framed_message))
|
|
self.framer.received_bytes(framed_message)
|
|
|
|
def pause_writing(self):
|
|
"""Transport calls when the send buffer is full."""
|
|
if not self.is_closing():
|
|
self._can_send.clear()
|
|
self.transport.pause_reading()
|
|
|
|
def resume_writing(self):
|
|
"""Transport calls when the send buffer has room."""
|
|
if not self._can_send.is_set():
|
|
self._can_send.set()
|
|
self.transport.resume_reading()
|
|
|
|
def connection_made(self, transport):
|
|
"""Called by asyncio when a connection is established.
|
|
|
|
Derived classes overriding this method must call this first."""
|
|
self.transport = transport
|
|
# This would throw if called on a closed SSL transport. Fixed
|
|
# in asyncio in Python 3.6.1 and 3.5.4
|
|
peer_address = transport.get_extra_info('peername')
|
|
# If the Socks proxy was used then _address is already set to
|
|
# the remote address
|
|
if self._address:
|
|
self._proxy_address = peer_address
|
|
else:
|
|
self._address = peer_address
|
|
self._pm_task = self.loop.create_task(self._receive_messages())
|
|
|
|
def connection_lost(self, exc):
|
|
"""Called by asyncio when the connection closes.
|
|
|
|
Tear down things done in connection_made."""
|
|
self._address = None
|
|
self.transport = None
|
|
self._task_group.cancel()
|
|
if self._pm_task:
|
|
self._pm_task.cancel()
|
|
# Release waiting tasks
|
|
self._can_send.set()
|
|
|
|
# External API
|
|
def default_framer(self):
|
|
"""Return a default framer."""
|
|
raise NotImplementedError
|
|
|
|
def peer_address(self):
|
|
"""Returns the peer's address (Python networking address), or None if
|
|
no connection or an error.
|
|
|
|
This is the result of socket.getpeername() when the connection
|
|
was made.
|
|
"""
|
|
return self._address
|
|
|
|
def peer_address_str(self):
|
|
"""Returns the peer's IP address and port as a human-readable
|
|
string."""
|
|
if not self._address:
|
|
return 'unknown'
|
|
ip_addr_str, port = self._address[:2]
|
|
if ':' in ip_addr_str:
|
|
return f'[{ip_addr_str}]:{port}'
|
|
else:
|
|
return f'{ip_addr_str}:{port}'
|
|
|
|
def is_closing(self):
|
|
"""Return True if the connection is closing."""
|
|
return not self.transport or self.transport.is_closing()
|
|
|
|
def abort(self):
|
|
"""Forcefully close the connection."""
|
|
if self.transport:
|
|
self.transport.abort()
|
|
|
|
# TODO: replace with synchronous_close
|
|
async def close(self, *, force_after=30):
|
|
"""Close the connection and return when closed."""
|
|
self._close()
|
|
if self._pm_task:
|
|
with suppress(CancelledError):
|
|
await asyncio.wait([self._pm_task], timeout=force_after)
|
|
self.abort()
|
|
await self._pm_task
|
|
|
|
def synchronous_close(self):
|
|
self._close()
|
|
if self._pm_task and not self._pm_task.done():
|
|
self._pm_task.cancel()
|
|
|
|
|
|
class MessageSession(SessionBase):
|
|
"""Session class for protocols where messages are not tied to responses,
|
|
such as the Bitcoin protocol.
|
|
|
|
To use as a client (connection-opening) session, pass host, port
|
|
and perhaps a proxy.
|
|
"""
|
|
async def _receive_messages(self):
|
|
while not self.is_closing():
|
|
try:
|
|
message = await self.framer.receive_message()
|
|
except BadMagicError as e:
|
|
magic, expected = e.args
|
|
self.logger.error(
|
|
f'bad network magic: got {magic} expected {expected}, '
|
|
f'disconnecting'
|
|
)
|
|
self._close()
|
|
except OversizedPayloadError as e:
|
|
command, payload_len = e.args
|
|
self.logger.error(
|
|
f'oversized payload of {payload_len:,d} bytes to command '
|
|
f'{command}, disconnecting'
|
|
)
|
|
self._close()
|
|
except BadChecksumError as e:
|
|
payload_checksum, claimed_checksum = e.args
|
|
self.logger.warning(
|
|
f'checksum mismatch: actual {payload_checksum.hex()} '
|
|
f'vs claimed {claimed_checksum.hex()}'
|
|
)
|
|
self._bump_errors()
|
|
else:
|
|
self.last_recv = time.perf_counter()
|
|
self.recv_count += 1
|
|
if self.recv_count % 10 == 0:
|
|
await self._update_concurrency()
|
|
await self._task_group.add(self._throttled_message(message))
|
|
|
|
async def _throttled_message(self, message):
|
|
"""Process a single request, respecting the concurrency limit."""
|
|
async with self._concurrency.semaphore:
|
|
try:
|
|
await self.handle_message(message)
|
|
except ProtocolError as e:
|
|
self.logger.error(f'{e}')
|
|
self._bump_errors()
|
|
except CancelledError:
|
|
raise
|
|
except Exception:
|
|
self.logger.exception(f'exception handling {message}')
|
|
self._bump_errors()
|
|
|
|
# External API
|
|
def default_framer(self):
|
|
"""Return a bitcoin framer."""
|
|
return BitcoinFramer(bytes.fromhex('e3e1f3e8'), 128_000_000)
|
|
|
|
async def handle_message(self, message):
|
|
"""message is a (command, payload) pair."""
|
|
pass
|
|
|
|
async def send_message(self, message):
|
|
"""Send a message (command, payload) over the network."""
|
|
await self._send_message(message)
|
|
|
|
|
|
class BatchError(Exception):
|
|
|
|
def __init__(self, request):
|
|
self.request = request # BatchRequest object
|
|
|
|
|
|
class BatchRequest:
|
|
"""Used to build a batch request to send to the server. Stores
|
|
the
|
|
|
|
Attributes batch and results are initially None.
|
|
|
|
Adding an invalid request or notification immediately raises a
|
|
ProtocolError.
|
|
|
|
On exiting the with clause, it will:
|
|
|
|
1) create a Batch object for the requests in the order they were
|
|
added. If the batch is empty this raises a ProtocolError.
|
|
|
|
2) set the "batch" attribute to be that batch
|
|
|
|
3) send the batch request and wait for a response
|
|
|
|
4) raise a ProtocolError if the protocol was violated by the
|
|
server. Currently this only happens if it gave more than one
|
|
response to any request
|
|
|
|
5) otherwise there is precisely one response to each Request. Set
|
|
the "results" attribute to the tuple of results; the responses
|
|
are ordered to match the Requests in the batch. Notifications
|
|
do not get a response.
|
|
|
|
6) if raise_errors is True and any individual response was a JSON
|
|
RPC error response, or violated the protocol in some way, a
|
|
BatchError exception is raised. Otherwise the caller can be
|
|
certain each request returned a standard result.
|
|
"""
|
|
|
|
def __init__(self, session, raise_errors):
|
|
self._session = session
|
|
self._raise_errors = raise_errors
|
|
self._requests = []
|
|
self.batch = None
|
|
self.results = None
|
|
|
|
def add_request(self, method, args=()):
|
|
self._requests.append(Request(method, args))
|
|
|
|
def add_notification(self, method, args=()):
|
|
self._requests.append(Notification(method, args))
|
|
|
|
def __len__(self):
|
|
return len(self._requests)
|
|
|
|
async def __aenter__(self):
|
|
return self
|
|
|
|
async def __aexit__(self, exc_type, exc_value, traceback):
|
|
if exc_type is None:
|
|
self.batch = Batch(self._requests)
|
|
message, event = self._session.connection.send_batch(self.batch)
|
|
await self._session._send_message(message)
|
|
await event.wait()
|
|
self.results = event.result
|
|
if self._raise_errors:
|
|
if any(isinstance(item, Exception) for item in event.result):
|
|
raise BatchError(self)
|
|
|
|
|
|
class RPCSession(SessionBase):
|
|
"""Base class for protocols where a message can lead to a response,
|
|
for example JSON RPC."""
|
|
|
|
def __init__(self, *, framer=None, loop=None, connection=None):
|
|
super().__init__(framer=framer, loop=loop)
|
|
self.connection = connection or self.default_connection()
|
|
|
|
async def _receive_messages(self):
|
|
while not self.is_closing():
|
|
try:
|
|
message = await self.framer.receive_message()
|
|
except MemoryError as e:
|
|
self.logger.warning(f'{e!r}')
|
|
continue
|
|
|
|
self.last_recv = time.perf_counter()
|
|
self.recv_count += 1
|
|
if self.recv_count % 10 == 0:
|
|
await self._update_concurrency()
|
|
|
|
try:
|
|
requests = self.connection.receive_message(message)
|
|
except ProtocolError as e:
|
|
self.logger.debug(f'{e}')
|
|
if e.error_message:
|
|
await self._send_message(e.error_message)
|
|
if e.code == JSONRPC.PARSE_ERROR:
|
|
self.max_errors = 0
|
|
self._bump_errors()
|
|
else:
|
|
for request in requests:
|
|
await self._task_group.add(self._throttled_request(request))
|
|
|
|
async def _throttled_request(self, request):
|
|
"""Process a single request, respecting the concurrency limit."""
|
|
async with self._concurrency.semaphore:
|
|
try:
|
|
result = await self.handle_request(request)
|
|
except (ProtocolError, RPCError) as e:
|
|
result = e
|
|
except CancelledError:
|
|
raise
|
|
except Exception:
|
|
self.logger.exception(f'exception handling {request}')
|
|
result = RPCError(JSONRPC.INTERNAL_ERROR,
|
|
'internal server error')
|
|
if isinstance(request, Request):
|
|
message = request.send_result(result)
|
|
if message:
|
|
await self._send_message(message)
|
|
if isinstance(result, Exception):
|
|
self._bump_errors()
|
|
|
|
def connection_lost(self, exc):
|
|
# Cancel pending requests and message processing
|
|
self.connection.raise_pending_requests(exc)
|
|
super().connection_lost(exc)
|
|
|
|
# External API
|
|
def default_connection(self):
|
|
"""Return a default connection if the user provides none."""
|
|
return JSONRPCConnection(JSONRPCv2)
|
|
|
|
def default_framer(self):
|
|
"""Return a default framer."""
|
|
return NewlineFramer()
|
|
|
|
async def handle_request(self, request):
|
|
pass
|
|
|
|
async def send_request(self, method, args=()):
|
|
"""Send an RPC request over the network."""
|
|
if self.is_closing():
|
|
raise asyncio.TimeoutError("Trying to send request on a recently dropped connection.")
|
|
message, event = self.connection.send_request(Request(method, args))
|
|
await self._send_message(message)
|
|
await event.wait()
|
|
result = event.result
|
|
if isinstance(result, Exception):
|
|
raise result
|
|
return result
|
|
|
|
async def send_notification(self, method, args=()):
|
|
"""Send an RPC notification over the network."""
|
|
message = self.connection.send_notification(Notification(method, args))
|
|
await self._send_message(message)
|
|
|
|
def send_batch(self, raise_errors=False):
|
|
"""Return a BatchRequest. Intended to be used like so:
|
|
|
|
async with session.send_batch() as batch:
|
|
batch.add_request("method1")
|
|
batch.add_request("sum", (x, y))
|
|
batch.add_notification("updated")
|
|
|
|
for result in batch.results:
|
|
...
|
|
|
|
Note that in some circumstances exceptions can be raised; see
|
|
BatchRequest doc string.
|
|
"""
|
|
return BatchRequest(self, raise_errors)
|
|
|
|
|
|
class Server:
|
|
"""A simple wrapper around an asyncio.Server object."""
|
|
|
|
def __init__(self, session_factory, host=None, port=None, *,
|
|
loop=None, **kwargs):
|
|
self.host = host
|
|
self.port = port
|
|
self.loop = loop or asyncio.get_event_loop()
|
|
self.server = None
|
|
self._session_factory = session_factory
|
|
self._kwargs = kwargs
|
|
|
|
async def listen(self):
|
|
self.server = await self.loop.create_server(
|
|
self._session_factory, self.host, self.port, **self._kwargs)
|
|
|
|
async def close(self):
|
|
"""Close the listening socket. This does not close any ServerSession
|
|
objects created to handle incoming connections.
|
|
"""
|
|
if self.server:
|
|
self.server.close()
|
|
await self.server.wait_closed()
|
|
self.server = None
|