import time import addresses import helper_random import protocol from dandelion import Dandelion from debug import logger from helper_threading import StoppableThread from inventory import Inventory from network.connectionpool import BMConnectionPool from objectracker import missingObjects class DownloadThread(StoppableThread): minPending = 200 maxRequestChunk = 1000 requestTimeout = 60 cleanInterval = 60 requestExpires = 3600 def __init__(self): super(DownloadThread, self).__init__(name="Downloader") logger.info("init download thread") self.lastCleaned = time.time() def cleanPending(self): deadline = time.time() - DownloadThread.requestExpires try: toDelete = [k for k, v in missingObjects.iteritems() if v < deadline] except RuntimeError: pass else: for i in toDelete: del missingObjects[i] self.lastCleaned = time.time() def run(self): while not self._stopped: requested = 0 # Choose downloading peers randomly connections = [x for x in BMConnectionPool().inboundConnections.values() + BMConnectionPool().outboundConnections.values() if x.fullyEstablished] helper_random.randomshuffle(connections) try: requestChunk = max(int(min(DownloadThread.maxRequestChunk, len(missingObjects)) / len(connections)), 1) except ZeroDivisionError: requestChunk = 1 for i in connections: now = time.time() # avoid unnecessary delay if i.skipUntil >= now: continue try: request = i.objectsNewToMe.randomKeys(requestChunk) except KeyError: continue payload = bytearray() chunkCount = 0 for chunk in request: if chunk in Inventory() and not Dandelion().hasHash(chunk): try: del i.objectsNewToMe[chunk] except KeyError: pass continue payload.extend(chunk) chunkCount += 1 missingObjects[chunk] = now if not chunkCount: continue payload[0:0] = addresses.encodeVarint(chunkCount) i.append_write_buf(protocol.CreatePacket('getdata', payload)) logger.debug("%s:%i Requesting %i objects", i.destination.host, i.destination.port, chunkCount) requested += chunkCount if time.time() >= self.lastCleaned + DownloadThread.cleanInterval: self.cleanPending() if not requested: self.stop.wait(1)