lbry-sdk/lbrynet/dht/peerfinder.py

65 lines
2.6 KiB
Python

import binascii
import logging
from twisted.internet import defer
from lbrynet.extras.daemon import conf
log = logging.getLogger(__name__)
class DummyPeerFinder:
"""This class finds peers which have announced to the DHT that they have certain blobs"""
def find_peers_for_blob(self, blob_hash, timeout=None, filter_self=True):
return defer.succeed([])
class DHTPeerFinder(DummyPeerFinder):
"""This class finds peers which have announced to the DHT that they have certain blobs"""
#implements(IPeerFinder)
def __init__(self, dht_node, peer_manager):
"""
dht_node - an instance of dht.Node class
peer_manager - an instance of PeerManager class
"""
self.dht_node = dht_node
self.peer_manager = peer_manager
self.peers = {}
self._ongoing_searchs = {}
def find_peers_for_blob(self, blob_hash, timeout=None, filter_self=True):
"""
Find peers for blob in the DHT
blob_hash (str): blob hash to look for
timeout (int): seconds to timeout after
filter_self (bool): if True, and if a peer for a blob is itself, filter it
from the result
Returns:
list of peers for the blob
"""
self.peers.setdefault(blob_hash, {(self.dht_node.externalIP, self.dht_node.peerPort,)})
if not blob_hash in self._ongoing_searchs or self._ongoing_searchs[blob_hash].called:
self._ongoing_searchs[blob_hash] = self._execute_peer_search(blob_hash, timeout)
peers = set(self._filter_self(blob_hash) if filter_self else self.peers[blob_hash])
return defer.succeed([self.peer_manager.get_peer(*peer) for peer in peers])
@defer.inlineCallbacks
def _execute_peer_search(self, blob_hash, timeout):
bin_hash = binascii.unhexlify(blob_hash)
finished_deferred = self.dht_node.iterativeFindValue(bin_hash, exclude=self.peers[blob_hash])
timeout = timeout or conf.settings['peer_search_timeout']
if timeout:
finished_deferred.addTimeout(timeout, self.dht_node.clock)
try:
peer_list = yield finished_deferred
self.peers[blob_hash].update({(host, port) for _, host, port in peer_list})
except defer.TimeoutError:
log.debug("DHT timed out while looking peers for blob %s after %s seconds", blob_hash, timeout)
finally:
del self._ongoing_searchs[blob_hash]
def _filter_self(self, blob_hash):
my_host, my_port = self.dht_node.externalIP, self.dht_node.peerPort
return {(host, port) for host, port in self.peers[blob_hash] if (host, port) != (my_host, my_port)}