import random import threading import time import addresses from debug import logger from helper_threading import StoppableThread from network.connectionpool import BMConnectionPool import protocol from state import missingObjects class DownloadThread(threading.Thread, StoppableThread): minPending = 200 maxRequestChunk = 1000 requestTimeout = 60 cleanInterval = 60 requestExpires = 3600 def __init__(self): threading.Thread.__init__(self, name="Downloader") self.initStop() self.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 = BMConnectionPool().inboundConnections.values() + BMConnectionPool().outboundConnections.values() random.shuffle(connections) try: requestChunk = max(int(min(DownloadThread.maxRequestChunk, len(missingObjects)) / len(connections)), 1) except ZeroDivisionError: requestChunk = 1 for i in connections: now = time.time() timedOut = now - DownloadThread.requestTimeout try: request = i.objectsNewToMe.randomKeys(requestChunk) except KeyError: continue payload = bytearray() payload.extend(addresses.encodeVarint(len(request))) for chunk in request: payload.extend(chunk) missingObjects[chunk] = now i.append_write_buf(protocol.CreatePacket('getdata', payload)) logger.debug("%s:%i Requesting %i objects", i.destination.host, i.destination.port, len(request)) requested += len(request) if time.time() >= self.lastCleaned + DownloadThread.cleanInterval: self.cleanPending() if not requested: self.stop.wait(5)