lbry-sdk/lbrynet/dht/node.py

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import logging
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import asyncio
import typing
import binascii
import contextlib
from lbrynet.utils import resolve_host
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from lbrynet.dht import constants
from lbrynet.dht.error import RemoteException
from lbrynet.dht.protocol.async_generator_junction import AsyncGeneratorJunction
from lbrynet.dht.protocol.distance import Distance
from lbrynet.dht.protocol.iterative_find import IterativeNodeFinder, IterativeValueFinder
from lbrynet.dht.protocol.protocol import KademliaProtocol
from lbrynet.dht.peer import KademliaPeer
if typing.TYPE_CHECKING:
from lbrynet.dht.peer import PeerManager
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log = logging.getLogger(__name__)
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class Node:
def __init__(self, loop: asyncio.BaseEventLoop, peer_manager: 'PeerManager', node_id: bytes, udp_port: int,
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internal_udp_port: int, peer_port: int, external_ip: str, rpc_timeout: typing.Optional[float] = 5.0):
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self.loop = loop
self.internal_udp_port = internal_udp_port
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self.protocol = KademliaProtocol(loop, peer_manager, node_id, external_ip, udp_port, peer_port, rpc_timeout)
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self.listening_port: asyncio.DatagramTransport = None
self.joined = asyncio.Event(loop=self.loop)
self._join_task: asyncio.Task = None
self._refresh_task: asyncio.Task = None
async def refresh_node(self):
while True:
# remove peers with expired blob announcements from the datastore
self.protocol.data_store.removed_expired_peers()
total_peers: typing.List['KademliaPeer'] = []
# add all peers in the routing table
total_peers.extend(self.protocol.routing_table.get_peers())
# add all the peers who have announed blobs to us
total_peers.extend(self.protocol.data_store.get_storing_contacts())
# get ids falling in the midpoint of each bucket that hasn't been recently updated
node_ids = self.protocol.routing_table.get_refresh_list(0, True)
# if we have 3 or fewer populated buckets get two random ids in the range of each to try and
# populate/split the buckets further
buckets_with_contacts = self.protocol.routing_table.buckets_with_contacts()
if buckets_with_contacts <= 3:
for i in range(buckets_with_contacts):
node_ids.append(self.protocol.routing_table.random_id_in_bucket_range(i))
node_ids.append(self.protocol.routing_table.random_id_in_bucket_range(i))
if self.protocol.routing_table.get_peers():
# if we have node ids to look up, perform the iterative search until we have k results
while node_ids:
peers = await self.peer_search(node_ids.pop())
total_peers.extend(peers)
else:
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fut = asyncio.Future(loop=self.loop)
self.loop.call_later(constants.refresh_interval // 4, fut.set_result, None)
await fut
continue
# ping the set of peers; upon success/failure the routing able and last replied/failed time will be updated
to_ping = [peer for peer in set(total_peers) if self.protocol.peer_manager.peer_is_good(peer) is not True]
if to_ping:
await self.protocol.ping_queue.enqueue_maybe_ping(*to_ping, delay=0)
fut = asyncio.Future(loop=self.loop)
self.loop.call_later(constants.refresh_interval, fut.set_result, None)
await fut
async def announce_blob(self, blob_hash: str) -> typing.List[bytes]:
announced_to_node_ids = []
while not announced_to_node_ids:
hash_value = binascii.unhexlify(blob_hash.encode())
assert len(hash_value) == constants.hash_length
peers = await self.peer_search(hash_value)
if not self.protocol.external_ip:
raise Exception("Cannot determine external IP")
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log.debug("Store to %i peers", len(peers))
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for peer in peers:
log.debug("store to %s %s %s", peer.address, peer.udp_port, peer.tcp_port)
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stored_to_tup = await asyncio.gather(
*(self.protocol.store_to_peer(hash_value, peer) for peer in peers), loop=self.loop
)
announced_to_node_ids.extend([node_id for node_id, contacted in stored_to_tup if contacted])
log.info("Stored %s to %i of %i attempted peers", binascii.hexlify(hash_value).decode()[:8],
len(announced_to_node_ids), len(peers))
return announced_to_node_ids
def stop(self) -> None:
if self.joined.is_set():
self.joined.clear()
if self._join_task:
self._join_task.cancel()
if self._refresh_task and not (self._refresh_task.done() or self._refresh_task.cancelled()):
self._refresh_task.cancel()
if self.protocol and self.protocol.ping_queue.running:
self.protocol.ping_queue.stop()
if self.listening_port is not None:
self.listening_port.close()
self._join_task = None
self.listening_port = None
log.info("Stopped DHT node")
async def start_listening(self, interface: str = '') -> None:
if not self.listening_port:
self.listening_port, _ = await self.loop.create_datagram_endpoint(
lambda: self.protocol, (interface, self.internal_udp_port)
)
log.info("DHT node listening on UDP %s:%i", interface, self.internal_udp_port)
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else:
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log.warning("Already bound to port %s", self.listening_port)
async def join_network(self, interface: typing.Optional[str] = '',
known_node_urls: typing.Optional[typing.List[typing.Tuple[str, int]]] = None):
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if not self.listening_port:
await self.start_listening(interface)
self.protocol.ping_queue.start()
self._refresh_task = self.loop.create_task(self.refresh_node())
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# resolve the known node urls
known_node_addresses = []
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url_to_addr = {}
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if known_node_urls:
for host, port in known_node_urls:
address = await resolve_host(host)
if (address, port) not in known_node_addresses:
known_node_addresses.append((address, port))
url_to_addr[address] = host
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if known_node_addresses:
while not self.protocol.routing_table.get_peers():
success = False
# ping the seed nodes, this will set their node ids (since we don't know them ahead of time)
for address, port in known_node_addresses:
peer = self.protocol.get_rpc_peer(KademliaPeer(self.loop, address, udp_port=port))
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try:
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await peer.ping()
success = True
except asyncio.TimeoutError:
log.warning("seed node (%s:%i) timed out in %s", url_to_addr.get(address, address), port,
round(self.protocol.rpc_timeout, 2))
if success:
break
# now that we have the seed nodes in routing, to an iterative lookup of our own id to populate the buckets
# in the routing table with good peers who are near us
async with self.peer_search_junction(self.protocol.node_id, max_results=16) as junction:
async for peers in junction:
for peer in peers:
try:
await self.protocol.get_rpc_peer(peer).ping()
except (asyncio.TimeoutError, RemoteException):
pass
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log.info("Joined DHT, %i peers known in %i buckets", len(self.protocol.routing_table.get_peers()),
self.protocol.routing_table.buckets_with_contacts())
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self.joined.set()
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def start(self, interface: str, known_node_urls: typing.List[typing.Tuple[str, int]]):
self._join_task = self.loop.create_task(
self.join_network(
interface=interface, known_node_urls=known_node_urls
)
)
def get_iterative_node_finder(self, key: bytes, shortlist: typing.Optional[typing.List] = None,
bottom_out_limit: int = constants.bottom_out_limit,
max_results: int = constants.k) -> IterativeNodeFinder:
return IterativeNodeFinder(self.loop, self.protocol.peer_manager, self.protocol.routing_table, self.protocol,
key, bottom_out_limit, max_results, None, shortlist)
def get_iterative_value_finder(self, key: bytes, shortlist: typing.Optional[typing.List] = None,
bottom_out_limit: int = 40,
max_results: int = -1) -> IterativeValueFinder:
return IterativeValueFinder(self.loop, self.protocol.peer_manager, self.protocol.routing_table, self.protocol,
key, bottom_out_limit, max_results, None, shortlist)
@contextlib.asynccontextmanager
async def stream_peer_search_junction(self, hash_queue: asyncio.Queue, bottom_out_limit=20,
max_results=-1) -> AsyncGeneratorJunction:
peer_generator = AsyncGeneratorJunction(self.loop)
async def _add_hashes_from_queue():
while True:
try:
blob_hash = await hash_queue.get()
except asyncio.CancelledError:
break
peer_generator.add_generator(
self.get_iterative_value_finder(
binascii.unhexlify(blob_hash.encode()), bottom_out_limit=bottom_out_limit,
max_results=max_results
)
)
add_hashes_task = self.loop.create_task(_add_hashes_from_queue())
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try:
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async with peer_generator as junction:
yield junction
await peer_generator.finished.wait()
except asyncio.CancelledError:
if add_hashes_task and not (add_hashes_task.done() or add_hashes_task.cancelled()):
add_hashes_task.cancel()
raise
finally:
if add_hashes_task and not (add_hashes_task.done() or add_hashes_task.cancelled()):
add_hashes_task.cancel()
def peer_search_junction(self, node_id: bytes, max_results=constants.k*2,
bottom_out_limit=20) -> AsyncGeneratorJunction:
peer_generator = AsyncGeneratorJunction(self.loop)
peer_generator.add_generator(
self.get_iterative_node_finder(
node_id, bottom_out_limit=bottom_out_limit, max_results=max_results
)
)
return peer_generator
async def peer_search(self, node_id: bytes, count=constants.k, max_results=constants.k*2,
bottom_out_limit=20) -> typing.List['KademliaPeer']:
accumulated: typing.List['KademliaPeer'] = []
async with self.peer_search_junction(node_id, max_results=max_results,
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bottom_out_limit=bottom_out_limit) as junction:
async for peers in junction:
accumulated.extend(peers)
distance = Distance(node_id)
accumulated.sort(key=lambda peer: distance(peer.node_id))
return accumulated[:count]
async def _accumulate_search_junction(self, search_queue: asyncio.Queue,
result_queue: asyncio.Queue):
try:
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async with self.stream_peer_search_junction(search_queue) as search_junction: # pylint: disable=E1701
async for peers in search_junction:
if peers:
result_queue.put_nowait(peers)
except asyncio.CancelledError:
return
def accumulate_peers(self, search_queue: asyncio.Queue,
peer_queue: typing.Optional[asyncio.Queue] = None) -> typing.Tuple[
asyncio.Queue, asyncio.Task]:
q = peer_queue or asyncio.Queue()
return q, asyncio.create_task(self._accumulate_search_junction(search_queue, q))