import binascii import logging from zope.interface import implements from twisted.internet import defer, reactor from lbrynet.interfaces import IPeerFinder from lbrynet.core.utils import short_hash log = logging.getLogger(__name__) class DHTPeerFinder(object): """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.next_manage_call = None def run_manage_loop(self): self._manage_peers() self.next_manage_call = reactor.callLater(60, self.run_manage_loop) def stop(self): log.info("Stopping DHT peer finder.") if self.next_manage_call is not None and self.next_manage_call.active(): self.next_manage_call.cancel() self.next_manage_call = None def _manage_peers(self): pass @defer.inlineCallbacks def find_peers_for_blob(self, blob_hash, timeout=None, filter_self=False): """ 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 """ def _trigger_timeout(): if not finished_deferred.called: log.debug("Peer search for %s timed out", short_hash(blob_hash)) finished_deferred.cancel() bin_hash = binascii.unhexlify(blob_hash) finished_deferred = self.dht_node.getPeersForBlob(bin_hash) if timeout is not None: reactor.callLater(timeout, _trigger_timeout) try: peer_list = yield finished_deferred except defer.CancelledError: peer_list = [] peers = set(peer_list) good_peers = [] for host, port in peers: if filter_self and (host, port) == (self.dht_node.externalIP, self.dht_node.peerPort): continue peer = self.peer_manager.get_peer(host, port) if peer.is_available() is True: good_peers.append(peer) defer.returnValue(good_peers) def get_most_popular_hashes(self, num_to_return): return self.dht_node.get_most_popular_hashes(num_to_return)