X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=apt_p2p%2FPeerManager.py;h=7513dfd318e1defd2b56642c8e001d62735dc12d;hb=a5dd904be839e2b2896483724d6238b5a970b5de;hp=447e69759bcacd16f2d98f235447349479995776;hpb=e6042f7b9084b3a317e3b61be4931c5eeed9fa41;p=quix0rs-apt-p2p.git diff --git a/apt_p2p/PeerManager.py b/apt_p2p/PeerManager.py index 447e697..7513dfd 100644 --- a/apt_p2p/PeerManager.py +++ b/apt_p2p/PeerManager.py @@ -8,219 +8,21 @@ from binascii import b2a_hex, a2b_hex import sha from twisted.internet import reactor, defer -from twisted.python import log, filepath +from twisted.python import log from twisted.trial import unittest from twisted.web2 import stream from twisted.web2.http import Response, splitHostPort from HTTPDownloader import Peer +from Streams import GrowingFileStream, StreamToFile from util import uncompact from Hash import PIECE_SIZE from apt_p2p_Khashmir.bencode import bdecode from apt_p2p_conf import config - class PeerError(Exception): """An error occurred downloading from peers.""" -class GrowingFileStream(stream.FileStream): - """Modified to stream data from a file as it becomes available. - - @ivar CHUNK_SIZE: the maximum size of chunks of data to send at a time - @ivar deferred: waiting for the result of the last read attempt - @ivar available: the number of bytes that are currently available to read - @ivar position: the current position in the file where the next read will begin - @ivar finished: True when no more data will be coming available - """ - - CHUNK_SIZE = 4*1024 - - def __init__(self, f, length = None): - stream.FileStream.__init__(self, f) - self.length = length - self.deferred = None - self.available = 0L - self.position = 0L - self.finished = False - - def updateAvailable(self, newlyAvailable): - """Update the number of bytes that are available. - - Call it with 0 to trigger reading of a fully read file. - - @param newlyAvailable: the number of bytes that just became available - """ - assert not self.finished - self.available += newlyAvailable - - # If a read is pending, let it go - if self.deferred and self.position < self.available: - # Try to read some data from the file - length = self.available - self.position - readSize = min(length, self.CHUNK_SIZE) - self.f.seek(self.position) - b = self.f.read(readSize) - bytesRead = len(b) - - # Check if end of file was reached - if bytesRead: - self.position += bytesRead - deferred = self.deferred - self.deferred = None - deferred.callback(b) - - def allAvailable(self): - """Indicate that no more data will be coming available.""" - self.finished = True - - # If a read is pending, let it go - if self.deferred: - if self.position < self.available: - # Try to read some data from the file - length = self.available - self.position - readSize = min(length, self.CHUNK_SIZE) - self.f.seek(self.position) - b = self.f.read(readSize) - bytesRead = len(b) - - # Check if end of file was reached - if bytesRead: - self.position += bytesRead - deferred = self.deferred - self.deferred = None - deferred.callback(b) - else: - # We're done - self._close() - deferred = self.deferred - self.deferred = None - deferred.callback(None) - else: - # We're done - self._close() - deferred = self.deferred - self.deferred = None - deferred.callback(None) - - def read(self, sendfile=False): - assert not self.deferred, "A previous read is still deferred." - - if self.f is None: - return None - - length = self.available - self.position - readSize = min(length, self.CHUNK_SIZE) - - # If we don't have any available, we're done or deferred - if readSize <= 0: - if self.finished: - self._close() - return None - else: - self.deferred = defer.Deferred() - return self.deferred - - # Try to read some data from the file - self.f.seek(self.position) - b = self.f.read(readSize) - bytesRead = len(b) - if not bytesRead: - # End of file was reached, we're done or deferred - if self.finished: - self._close() - return None - else: - self.deferred = defer.Deferred() - return self.deferred - else: - self.position += bytesRead - return b - - def _close(self): - """Close the temporary file and remove it.""" - self.f.close() - filepath.FilePath(self.f.name).remove() - self.f = None - -class StreamToFile: - """Save a stream to a partial file and hash it. - - @type stream: L{twisted.web2.stream.IByteStream} - @ivar stream: the input stream being read - @type outFile: L{twisted.python.filepath.FilePath} - @ivar outFile: the file being written - @type hash: C{sha1} - @ivar hash: the hash object for the data - @type position: C{int} - @ivar position: the current file position to write the next data to - @type length: C{int} - @ivar length: the position in the file to not write beyond - @type doneDefer: L{twisted.internet.defer.Deferred} - @ivar doneDefer: the deferred that will fire when done writing - """ - - def __init__(self, inputStream, outFile, start = 0, length = None): - """Initializes the file. - - @type inputStream: L{twisted.web2.stream.IByteStream} - @param inputStream: the input stream to read from - @type outFile: L{twisted.python.filepath.FilePath} - @param outFile: the file to write to - @type start: C{int} - @param start: the file position to start writing at - (optional, defaults to the start of the file) - @type length: C{int} - @param length: the maximum amount of data to write to the file - (optional, defaults to not limiting the writing to the file - """ - self.stream = inputStream - self.outFile = outFile - self.hash = sha.new() - self.position = start - self.length = None - if length is not None: - self.length = start + length - self.doneDefer = None - - def run(self): - """Start the streaming. - - @rtype: L{twisted.internet.defer.Deferred} - """ - log.msg('Started streaming %r bytes to file at position %d' % (self.length, self.position)) - self.doneDefer = stream.readStream(self.stream, self._gotData) - self.doneDefer.addCallbacks(self._done, self._error) - return self.doneDefer - - def _gotData(self, data): - """Process the received data.""" - if self.outFile.closed: - raise PeerError, "outFile was unexpectedly closed" - - if data is None: - raise PeerError, "Data is None?" - - # Make sure we don't go too far - if self.length is not None and self.position + len(data) > self.length: - data = data[:(self.length - self.position)] - - # Write and hash the streamed data - self.outFile.seek(self.position) - self.outFile.write(data) - self.hash.update(data) - self.position += len(data) - - def _done(self, result): - """Return the result.""" - log.msg('Streaming is complete') - return self.hash.digest() - - def _error(self, err): - """Log the error.""" - log.msg('Streaming error') - log.err(err) - return err - class FileDownload: """Manage a download from a list of peers or a mirror. @@ -276,6 +78,7 @@ class FileDownload: self.compact_peers = compact_peers self.path = '/~/' + quote_plus(hash.expected()) + self.defer = None self.mirror_path = None self.pieces = None self.started = False @@ -369,7 +172,7 @@ class FileDownload: # del self.peers[site] # Start the DHT lookup - lookupDefer = self.manager.dht.getValue(key) + lookupDefer = self.manager.dht.get(key) lookupDefer.addBoth(self._getDHTPieces, key) def _getDHTPieces(self, results, key): @@ -485,12 +288,12 @@ class FileDownload: """Sort the peers by their rank (highest ranked at the end).""" def sort(a, b): """Sort peers by their rank.""" - if a.rank > b.rank: + if self.peers[a]['peer'].rank > self.peers[b]['peer'].rank: return 1 - elif a.rank < b.rank: + elif self.peers[a]['peer'].rank < self.peers[b]['peer'].rank: return -1 return 0 - self.peerlist.sort(sort) + self.sitelist.sort(sort) def startDownload(self): """Start the download from the peers.""" @@ -501,111 +304,169 @@ class FileDownload: log.msg('Starting to download %s' % self.path) self.started = True assert self.pieces, "You must initialize the piece hashes first" - self.peerlist = [self.peers[site]['peer'] for site in self.peers] - # Use the mirror if there are few peers - if len(self.peerlist) < config.getint('DEFAULT', 'MIN_DOWNLOAD_PEERS'): - parsed = urlparse(self.mirror) - if parsed[0] == "http": - site = splitHostPort(parsed[0], parsed[1]) - self.mirror_path = urlunparse(('', '') + parsed[2:]) - peer = self.manager.getPeer(site, mirror = True) - self.peerlist.append(peer) + self.sitelist = self.peers.keys() # Special case if there's only one good peer left -# if len(self.peerlist) == 1: -# log.msg('Downloading from peer %r' % (self.peerlist[0], )) -# self.defer.callback(self.peerlist[0].get(self.path)) +# if len(self.sitelist) == 1: +# log.msg('Downloading from peer %r' % (self.peers[self.sitelist[0]]['peer'], )) +# self.defer.callback(self.peers[self.sitelist[0]]['peer'].get(self.path)) # return - # Start sending the return file - self.stream = GrowingFileStream(self.file, self.hash.expSize) - resp = Response(200, {}, self.stream) - self.defer.callback(resp) - # Begin to download the pieces self.outstanding = 0 self.nextFinish = 0 self.completePieces = [False for piece in self.pieces] + self.addedMirror = False + self.addMirror() self.getPieces() + + def addMirror(self): + """Use the mirror if there are few peers.""" + if not self.addedMirror and len(self.sitelist) + self.outstanding < config.getint('DEFAULT', 'MIN_DOWNLOAD_PEERS'): + self.addedMirror = True + parsed = urlparse(self.mirror) + if parsed[0] == "http": + site = splitHostPort(parsed[0], parsed[1]) + self.mirror_path = urlunparse(('', '') + parsed[2:]) + peer = self.manager.getPeer(site, mirror = True) + self.peers[site] = {} + self.peers[site]['peer'] = peer + self.sitelist.append(site) #{ Downloading the pieces def getPieces(self): """Download the next pieces from the peers.""" + if self.file.closed: + log.msg('Download has been aborted for %s' % self.path) + self.stream.allAvailable(remove = True) + return + self.sort() piece = self.nextFinish - while self.outstanding < 4 and self.peerlist and piece < len(self.completePieces): + while self.outstanding < 4 and self.sitelist and piece < len(self.completePieces): if self.completePieces[piece] == False: # Send a request to the highest ranked peer - peer = self.peerlist.pop() - self.completePieces[piece] = peer - log.msg('Sending a request for piece %d to peer %r' % (piece, peer)) + site = self.sitelist.pop() + self.completePieces[piece] = site + log.msg('Sending a request for piece %d to peer %r' % (piece, self.peers[site]['peer'])) self.outstanding += 1 - if peer.mirror: - df = peer.getRange(self.mirror_path, piece*PIECE_SIZE, (piece+1)*PIECE_SIZE - 1) + path = self.path + if self.peers[site]['peer'].mirror: + path = self.mirror_path + if len(self.completePieces) > 1: + df = self.peers[site]['peer'].getRange(path, piece*PIECE_SIZE, (piece+1)*PIECE_SIZE - 1) else: - df = peer.getRange(self.path, piece*PIECE_SIZE, (piece+1)*PIECE_SIZE - 1) + df = self.peers[site]['peer'].get(path) reactor.callLater(0, df.addCallbacks, *(self._getPiece, self._getError), - **{'callbackArgs': (piece, peer), - 'errbackArgs': (piece, peer)}) + **{'callbackArgs': (piece, site), + 'errbackArgs': (piece, site)}) piece += 1 # Check if we're done if self.outstanding <= 0 and self.nextFinish >= len(self.completePieces): - log.msg('We seem to be done with all pieces') - self.stream.allAvailable() + log.msg('Download is complete for %s' % self.path) + self.stream.allAvailable(remove = True) + + # Check if we ran out of peers + if self.outstanding <= 0 and not self.sitelist and False in self.completePieces: + log.msg("Download failed, no peers left to try.") + if self.defer: + # Send a return error + df = self.defer + self.defer = None + resp = Response(500, {}, None) + df.callback(resp) + else: + # Already streaming the response, try and abort + self.stream.allAvailable(remove = True) - def _getPiece(self, response, piece, peer): + def _getPiece(self, response, piece, site): """Process the retrieved headers from the peer.""" - log.msg('Got response for piece %d from peer %r' % (piece, peer)) - if ((len(self.completePieces) > 1 and response.code != 206) or + if response.code == 404: + # Peer no longer has this file, move on + log.msg('Peer sharing piece %d no longer has it: %r' % (piece, self.peers[site]['peer'])) + self.completePieces[piece] = False + if response.stream and response.stream.length: + stream.readAndDiscard(response.stream) + + # Don't add the site back, just move on + site = None + elif ((len(self.completePieces) > 1 and response.code != 206) or (response.code not in (200, 206))): # Request failed, try a different peer - log.msg('Wrong response type %d for piece %d from peer %r' % (response.code, piece, peer)) - peer.hashError('Peer responded with the wrong type of download: %r' % response.code) + log.msg('Wrong response type %d for piece %d from peer %r' % (response.code, piece, self.peers[site]['peer'])) + self.peers[site]['peer'].hashError('Peer responded with the wrong type of download: %r' % response.code) self.completePieces[piece] = False + self.peers[site]['errors'] = self.peers[site].get('errors', 0) + 1 if response.stream and response.stream.length: stream.readAndDiscard(response.stream) + + # After 3 errors in a row, drop the peer + if self.peers[site]['errors'] >= 3: + site = None else: + if self.defer: + # Start sending the return file + df = self.defer + self.defer = None + self.stream = GrowingFileStream(self.file, self.hash.expSize) + + # Get the headers from the peer's response + headers = {} + if response.headers.hasHeader('last-modified'): + headers['last-modified'] = response.headers.getHeader('last-modified') + resp = Response(200, headers, self.stream) + df.callback(resp) + # Read the response stream to the file - log.msg('Streaming piece %d from peer %r' % (piece, peer)) + log.msg('Streaming piece %d from peer %r' % (piece, self.peers[site]['peer'])) if response.code == 206: - df = StreamToFile(response.stream, self.file, piece*PIECE_SIZE, - PIECE_SIZE).run() + df = StreamToFile(self.hash.newPieceHasher(), response.stream, + self.file, piece*PIECE_SIZE, PIECE_SIZE).run() else: - df = StreamToFile(response.stream, self.file).run() + df = StreamToFile(self.hash.newHasher(), response.stream, + self.file).run() reactor.callLater(0, df.addCallbacks, *(self._gotPiece, self._gotError), - **{'callbackArgs': (piece, peer), - 'errbackArgs': (piece, peer)}) + **{'callbackArgs': (piece, site), + 'errbackArgs': (piece, site)}) self.outstanding -= 1 - self.peerlist.append(peer) + if site: + self.sitelist.append(site) + else: + self.addMirror() self.getPieces() - def _getError(self, err, piece, peer): + def _getError(self, err, piece, site): """Peer failed, try again.""" - log.msg('Got error for piece %d from peer %r' % (piece, peer)) + log.msg('Got error for piece %d from peer %r' % (piece, self.peers[site]['peer'])) self.outstanding -= 1 - self.peerlist.append(peer) + self.peers[site]['errors'] = self.peers[site].get('errors', 0) + 1 + if self.peers[site]['errors'] < 3: + self.sitelist.append(site) + else: + self.addMirror() self.completePieces[piece] = False self.getPieces() log.err(err) - def _gotPiece(self, response, piece, peer): + def _gotPiece(self, hash, piece, site): """Process the retrieved piece from the peer.""" - log.msg('Finished streaming piece %d from peer %r: %r' % (piece, peer, response)) - if self.pieces[piece] and response != self.pieces[piece]: + if self.pieces[piece] and hash.digest() != self.pieces[piece]: # Hash doesn't match - log.msg('Hash error for piece %d from peer %r' % (piece, peer)) - peer.hashError('Piece received from peer does not match expected') + log.msg('Hash error for piece %d from peer %r' % (piece, self.peers[site]['peer'])) + self.peers[site]['peer'].hashError('Piece received from peer does not match expected') + self.peers[site]['errors'] = self.peers[site].get('errors', 0) + 1 self.completePieces[piece] = False else: # Successfully completed one of several pieces - log.msg('Finished with piece %d from peer %r' % (piece, peer)) + log.msg('Finished with piece %d from peer %r' % (piece, self.peers[site]['peer'])) self.completePieces[piece] = True + self.peers[site]['errors'] = 0 while (self.nextFinish < len(self.completePieces) and self.completePieces[self.nextFinish] == True): self.nextFinish += 1 @@ -613,10 +474,11 @@ class FileDownload: self.getPieces() - def _gotError(self, err, piece, peer): + def _gotError(self, err, piece, site): """Piece download failed, try again.""" - log.msg('Error streaming piece %d from peer %r: %r' % (piece, peer, response)) + log.msg('Error streaming piece %d from peer %r: %r' % (piece, self.peers[site]['peer'], err)) log.err(err) + self.peers[site]['errors'] = self.peers[site].get('errors', 0) + 1 self.completePieces[piece] = False self.getPieces() @@ -625,7 +487,7 @@ class PeerManager: @type cache_dir: L{twisted.python.filepath.FilePath} @ivar cache_dir: the directory to use for storing all files - @type dht: L{interfaces.IDHT} + @type dht: L{DHTManager.DHT} @ivar dht: the DHT instance @type stats: L{stats.StatsLogger} @ivar stats: the statistics logger to record sent data to