import asyncio
import time
import logging
import typing
import binascii
from typing import Optional
from lbry.error import InvalidBlobHashError, InvalidDataError
from lbry.blob_exchange.serialization import BlobResponse, BlobRequest
from lbry.utils import cache_concurrent
if typing.TYPE_CHECKING:
from lbry.blob.blob_file import AbstractBlob
from lbry.blob.writer import HashBlobWriter
from lbry.connection_manager import ConnectionManager
log = logging.getLogger(__name__)
class BlobExchangeClientProtocol(asyncio.Protocol):
def __init__(self, loop: asyncio.AbstractEventLoop, peer_timeout: typing.Optional[float] = 10,
connection_manager: typing.Optional['ConnectionManager'] = None):
self.loop = loop
self.peer_port: typing.Optional[int] = None
self.peer_address: typing.Optional[str] = None
self.transport: typing.Optional[asyncio.Transport] = None
self.peer_timeout = peer_timeout
self.connection_manager = connection_manager
self.writer: typing.Optional['HashBlobWriter'] = None
self.blob: typing.Optional['AbstractBlob'] = None
self._blob_bytes_received = 0
self._response_fut: typing.Optional[asyncio.Future] = None
self.buf = b''
# this is here to handle the race when the downloader is closed right as response_fut gets a result
self.closed = asyncio.Event(loop=self.loop)
def data_received(self, data: bytes):
if self.connection_manager:
if not self.peer_address:
addr_info = self.transport.get_extra_info('peername')
self.peer_address, self.peer_port = addr_info
# assert self.peer_address is not None
self.connection_manager.received_data(f"{self.peer_address}:{self.peer_port}", len(data))
if not self.transport or self.transport.is_closing():
log.warning("transport closing, but got more bytes from %s:%i\n%s", self.peer_address, self.peer_port,
binascii.hexlify(data))
if self._response_fut and not self._response_fut.done():
self._response_fut.cancel()
return
if not self._response_fut:
log.warning("Protocol received data before expected, probable race on keep alive. Closing transport.")
return self.close()
if self._blob_bytes_received and not self.writer.closed():
return self._write(data)
response = BlobResponse.deserialize(self.buf + data)
if not response.responses and not self._response_fut.done():
self.buf += data
return
else:
self.buf = b''
if response.responses and self.blob:
blob_response = response.get_blob_response()
if blob_response and not blob_response.error and blob_response.blob_hash == self.blob.blob_hash:
# set the expected length for the incoming blob if we didn't know it
self.blob.set_length(blob_response.length)
elif blob_response and not blob_response.error and self.blob.blob_hash != blob_response.blob_hash:
# the server started sending a blob we didn't request
log.warning("%s started sending blob we didn't request %s instead of %s", self.peer_address,
blob_response.blob_hash, self.blob.blob_hash)
return
if response.responses:
log.debug("got response from %s:%i <- %s", self.peer_address, self.peer_port, response.to_dict())
# fire the Future with the response to our request
self._response_fut.set_result(response)
if response.blob_data and self.writer and not self.writer.closed():
# log.debug("got %i blob bytes from %s:%i", len(response.blob_data), self.peer_address, self.peer_port)
# write blob bytes if we're writing a blob and have blob bytes to write
self._write(response.blob_data)
def _write(self, data: bytes):
if len(data) > (self.blob.get_length() - self._blob_bytes_received):
data = data[:(self.blob.get_length() - self._blob_bytes_received)]
log.warning("got more than asked from %s:%d, probable sendfile bug", self.peer_address, self.peer_port)
self._blob_bytes_received += len(data)
try:
self.writer.write(data)
except OSError as err:
log.error("error downloading blob from %s:%i: %s", self.peer_address, self.peer_port, err)
if self._response_fut and not self._response_fut.done():
self._response_fut.set_exception(err)
except asyncio.TimeoutError as err:
log.error("%s downloading blob from %s:%i", str(err), self.peer_address, self.peer_port)
if self._response_fut and not self._response_fut.done():
self._response_fut.set_exception(err)
async def _download_blob(self) -> typing.Tuple[int, Optional['BlobExchangeClientProtocol']]: # pylint: disable=too-many-return-statements
"""
:return: download success (bool), connected protocol (BlobExchangeClientProtocol)
"""
start_time = time.perf_counter()
request = BlobRequest.make_request_for_blob_hash(self.blob.blob_hash)
blob_hash = self.blob.blob_hash
if not self.peer_address:
addr_info = self.transport.get_extra_info('peername')
self.peer_address, self.peer_port = addr_info
try:
msg = request.serialize()
log.debug("send request to %s:%i -> %s", self.peer_address, self.peer_port, msg.decode())
self.transport.write(msg)
if self.connection_manager:
self.connection_manager.sent_data(f"{self.peer_address}:{self.peer_port}", len(msg))
response: BlobResponse = await asyncio.wait_for(self._response_fut, self.peer_timeout, loop=self.loop)
availability_response = response.get_availability_response()
price_response = response.get_price_response()
blob_response = response.get_blob_response()
if self.closed.is_set():
msg = f"cancelled blob request for {blob_hash} immediately after we got a response"
log.warning(msg)
raise asyncio.CancelledError(msg)
if (not blob_response or blob_response.error) and\
(not availability_response or not availability_response.available_blobs):
log.warning("%s not in availability response from %s:%i", self.blob.blob_hash, self.peer_address,
self.peer_port)
log.warning(response.to_dict())
return self._blob_bytes_received, self.close()
elif availability_response and availability_response.available_blobs and \
availability_response.available_blobs != [self.blob.blob_hash]:
log.warning("blob availability response doesn't match our request from %s:%i",
self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
elif not availability_response:
log.warning("response from %s:%i did not include an availability response (we requested %s)",
self.peer_address, self.peer_port, blob_hash)
return self._blob_bytes_received, self.close()
if not price_response or price_response.blob_data_payment_rate != 'RATE_ACCEPTED':
log.warning("data rate rejected by %s:%i", self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
if not blob_response or blob_response.error:
log.warning("blob can't be downloaded from %s:%i", self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
if not blob_response.error and blob_response.blob_hash != self.blob.blob_hash:
log.warning("incoming blob hash mismatch from %s:%i", self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
if self.blob.length is not None and self.blob.length != blob_response.length:
log.warning("incoming blob unexpected length from %s:%i", self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
msg = f"downloading {self.blob.blob_hash[:8]} from {self.peer_address}:{self.peer_port}," \
f" timeout in {self.peer_timeout}"
log.debug(msg)
msg = f"downloaded {self.blob.blob_hash[:8]} from {self.peer_address}:{self.peer_port}"
await asyncio.wait_for(self.writer.finished, self.peer_timeout, loop=self.loop)
log.info("%s at %fMB/s", msg,
round((float(self._blob_bytes_received) /
float(time.perf_counter() - start_time)) / 1000000.0, 2))
# await self.blob.finished_writing.wait() not necessary, but a dangerous change. TODO: is it needed?
return self._blob_bytes_received, self
except asyncio.TimeoutError:
return self._blob_bytes_received, self.close()
except (InvalidBlobHashError, InvalidDataError):
log.warning("invalid blob from %s:%i", self.peer_address, self.peer_port)
return self._blob_bytes_received, self.close()
def close(self):
self.closed.set()
if self._response_fut and not self._response_fut.done():
self._response_fut.cancel()
if self.writer and not self.writer.closed():
self.writer.close_handle()
self._response_fut = None
self.writer = None
self.blob = None
if self.transport:
self.transport.close()
self.transport = None
self.buf = b''
async def download_blob(self, blob: 'AbstractBlob') -> typing.Tuple[int, Optional['BlobExchangeClientProtocol']]:
self.closed.clear()
blob_hash = blob.blob_hash
if blob.get_is_verified() or not blob.is_writeable():
return 0, self
try:
self._blob_bytes_received = 0
self.blob, self.writer = blob, blob.get_blob_writer(self.peer_address, self.peer_port)
self._response_fut = asyncio.Future(loop=self.loop)
return await self._download_blob()
except OSError:
# i'm not sure how to fix this race condition - jack
log.warning("race happened downloading %s from %s:%s", blob_hash, self.peer_address, self.peer_port)
# return self._blob_bytes_received, self.transport
raise
except asyncio.TimeoutError:
if self._response_fut and not self._response_fut.done():
self._response_fut.cancel()
self.close()
return self._blob_bytes_received, None
except asyncio.CancelledError:
self.close()
raise
finally:
if self.writer and not self.writer.closed():
self.writer.close_handle()
self.writer = None
def connection_made(self, transport: asyncio.Transport):
addr = transport.get_extra_info('peername')
self.peer_address, self.peer_port = addr[0], addr[1]
self.transport = transport
if self.connection_manager:
self.connection_manager.connection_made(f"{self.peer_address}:{self.peer_port}")
log.debug("connection made to %s:%i", self.peer_address, self.peer_port)
def connection_lost(self, exc):
if self.connection_manager:
self.connection_manager.outgoing_connection_lost(f"{self.peer_address}:{self.peer_port}")
log.debug("connection lost to %s:%i (reason: %s, %s)", self.peer_address, self.peer_port, str(exc),
str(type(exc)))
self.close()
@cache_concurrent
async def request_blob(loop: asyncio.AbstractEventLoop, blob: Optional['AbstractBlob'], address: str,
tcp_port: int, peer_connect_timeout: float, blob_download_timeout: float,
connected_protocol: Optional['BlobExchangeClientProtocol'] = None,
connection_id: int = 0, connection_manager: Optional['ConnectionManager'] = None)\
-> typing.Tuple[int, Optional['BlobExchangeClientProtocol']]:
"""
Returns [<amount of bytes received>, <client protocol if connected>]
"""
protocol = connected_protocol
if not connected_protocol or not connected_protocol.transport or connected_protocol.transport.is_closing():
connected_protocol = None
protocol = BlobExchangeClientProtocol(
loop, blob_download_timeout, connection_manager
)
else:
log.debug("reusing connection for %s:%d", address, tcp_port)
try:
if not connected_protocol:
await asyncio.wait_for(loop.create_connection(lambda: protocol, address, tcp_port),
peer_connect_timeout, loop=loop)
connected_protocol = protocol
if blob is None or blob.get_is_verified() or not blob.is_writeable():
# blob is None happens when we are just opening a connection
# file exists but not verified means someone is writing right now, give it time, come back later
return 0, connected_protocol
return await connected_protocol.download_blob(blob)
except (asyncio.TimeoutError, ConnectionRefusedError, ConnectionAbortedError, OSError):
return 0, None