forked from LBRYCommunity/lbry-sdk
147 lines
6.8 KiB
Python
147 lines
6.8 KiB
Python
import asyncio
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import typing
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import logging
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from lbry.utils import cache_concurrent
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from lbry.blob_exchange.client import request_blob
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if typing.TYPE_CHECKING:
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from lbry.conf import Config
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from lbry.dht.node import Node
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from lbry.dht.peer import KademliaPeer
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from lbry.blob.blob_manager import BlobManager
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from lbry.blob.blob_file import AbstractBlob
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from lbry.blob_exchange.client import BlobExchangeClientProtocol
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log = logging.getLogger(__name__)
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class BlobDownloader:
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BAN_FACTOR = 2.0 # fixme: when connection manager gets implemented, move it out from here
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def __init__(self, loop: asyncio.AbstractEventLoop, config: 'Config', blob_manager: 'BlobManager',
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peer_queue: asyncio.Queue):
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self.loop = loop
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self.config = config
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self.blob_manager = blob_manager
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self.peer_queue = peer_queue
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self.active_connections: typing.Dict['KademliaPeer', asyncio.Task] = {} # active request_blob calls
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self.ignored: typing.Dict['KademliaPeer', int] = {}
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self.scores: typing.Dict['KademliaPeer', int] = {}
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self.failures: typing.Dict['KademliaPeer', int] = {}
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self.connection_failures: typing.Set['KademliaPeer'] = set()
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self.connections: typing.Dict['KademliaPeer', 'BlobExchangeClientProtocol'] = {}
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self.is_running = asyncio.Event(loop=self.loop)
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def should_race_continue(self, blob: 'AbstractBlob'):
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max_probes = self.config.max_connections_per_download * (1 if self.connections else 10)
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if len(self.active_connections) >= max_probes:
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return False
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return not (blob.get_is_verified() or not blob.is_writeable())
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async def request_blob_from_peer(self, blob: 'AbstractBlob', peer: 'KademliaPeer', connection_id: int = 0,
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just_probe: bool = False):
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if blob.get_is_verified():
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return
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start = self.loop.time()
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bytes_received, protocol = await request_blob(
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self.loop, blob if not just_probe else None, peer.address, peer.tcp_port, self.config.peer_connect_timeout,
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self.config.blob_download_timeout, connected_protocol=self.connections.get(peer),
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connection_id=connection_id, connection_manager=self.blob_manager.connection_manager
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)
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if not bytes_received and not protocol and peer not in self.connection_failures:
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self.connection_failures.add(peer)
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if not protocol and peer not in self.ignored:
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self.ignored[peer] = self.loop.time()
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log.debug("drop peer %s:%i", peer.address, peer.tcp_port)
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self.failures[peer] = self.failures.get(peer, 0) + 1
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if peer in self.connections:
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del self.connections[peer]
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elif protocol:
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log.debug("keep peer %s:%i", peer.address, peer.tcp_port)
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self.failures[peer] = 0
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self.connections[peer] = protocol
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elapsed = self.loop.time() - start
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self.scores[peer] = bytes_received / elapsed if bytes_received and elapsed else 1
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async def new_peer_or_finished(self):
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active_tasks = list(self.active_connections.values()) + [asyncio.sleep(1)]
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await asyncio.wait(active_tasks, loop=self.loop, return_when='FIRST_COMPLETED')
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def cleanup_active(self):
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if not self.active_connections and not self.connections:
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self.clearbanned()
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to_remove = [peer for (peer, task) in self.active_connections.items() if task.done()]
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for peer in to_remove:
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del self.active_connections[peer]
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def clearbanned(self):
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now = self.loop.time()
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self.ignored = {
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peer: when for (peer, when) in self.ignored.items()
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if (now - when) < min(30.0, (self.failures.get(peer, 0) ** self.BAN_FACTOR))
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}
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@cache_concurrent
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async def download_blob(self, blob_hash: str, length: typing.Optional[int] = None,
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connection_id: int = 0) -> 'AbstractBlob':
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blob = self.blob_manager.get_blob(blob_hash, length)
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if blob.get_is_verified():
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return blob
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self.is_running.set()
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tried_for_this_blob: typing.Set['KademliaPeer'] = set()
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try:
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while not blob.get_is_verified() and self.is_running.is_set():
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batch: typing.Set['KademliaPeer'] = set(self.connections.keys())
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while not self.peer_queue.empty():
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batch.update(self.peer_queue.get_nowait())
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log.debug(
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"%s running, %d peers, %d ignored, %d active, %s connections", blob_hash[:6],
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len(batch), len(self.ignored), len(self.active_connections), len(self.connections)
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)
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re_add: typing.Set['KademliaPeer'] = set()
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for peer in sorted(batch, key=lambda peer: self.scores.get(peer, 0), reverse=True):
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if peer in self.ignored:
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continue
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if peer in tried_for_this_blob:
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continue
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if peer in self.active_connections:
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if peer not in re_add:
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re_add.add(peer)
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continue
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if not self.should_race_continue(blob):
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break
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log.debug("request %s from %s:%i", blob_hash[:8], peer.address, peer.tcp_port)
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t = self.loop.create_task(self.request_blob_from_peer(blob, peer, connection_id))
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self.active_connections[peer] = t
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tried_for_this_blob.add(peer)
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if not re_add:
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self.peer_queue.put_nowait(list(batch))
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await self.new_peer_or_finished()
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self.cleanup_active()
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log.debug("downloaded %s", blob_hash[:8])
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return blob
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finally:
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blob.close()
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if self.loop.is_running():
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self.loop.call_soon(self.cleanup_active)
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def close(self):
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self.connection_failures.clear()
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self.scores.clear()
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self.ignored.clear()
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self.is_running.clear()
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for protocol in self.connections.values():
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protocol.close()
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async def download_blob(loop, config: 'Config', blob_manager: 'BlobManager', node: 'Node',
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blob_hash: str) -> 'AbstractBlob':
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search_queue = asyncio.Queue(loop=loop, maxsize=config.max_connections_per_download)
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search_queue.put_nowait(blob_hash)
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peer_queue, accumulate_task = node.accumulate_peers(search_queue)
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downloader = BlobDownloader(loop, config, blob_manager, peer_queue)
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try:
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return await downloader.download_blob(blob_hash)
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finally:
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if accumulate_task and not accumulate_task.done():
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accumulate_task.cancel()
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downloader.close()
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