def test_piece_queue_one_piece(self):
test_bytes = '\x00'
test_hash = hashlib.sha1(test_bytes).digest()
piece = Piece(fake_client, 1, 1, test_hash, test_dir)
piece_queue = PieceQueue([piece])
test_piece = piece_queue.get_first_piece()
self.assertEqual(test_piece.index, piece.index)
def test_piece_queue_random(self):
test_bytes = '\x00'
test_hash = hashlib.sha1(test_bytes).digest()
piece = Piece(fake_client, 1, 1, test_hash, test_dir)
piece_queue = PieceQueue([piece])
test_piece = piece_queue.get_next_random()
self.assertEqual(test_piece.index, piece.index)
test_piece.add_block(0, test_bytes)
self.assertTrue(piece.check_if_finished())
self.assertTrue(piece.check_info_hash())
def test_piece_queue_random_five(self):
pieces = []
test_bytes_list = ['\x00', '\x01', '\x02', '\x03', '\x04']
for i in range(5):
test_bytes = test_bytes_list[i]
test_hash = hashlib.sha1(test_bytes).digest()
piece = Piece(fake_client, i, 1, test_hash, test_dir)
pieces.append(piece)
piece_queue = PieceQueue(pieces)
for i in xrange(5):
test_piece = piece_queue.get_next_random()
self.assertEqual(test_piece.index, pieces[test_piece.index].index)
def test_piece_queue_random_two(self):
test_bytes0 = '\x00'
test_hash0 = hashlib.sha1(test_bytes0).digest()
piece0 = Piece(fake_client, 0, 1, test_hash0, test_dir)
test_bytes1 = '\x01'
test_hash1 = hashlib.sha1(test_bytes1).digest()
piece1 = Piece(fake_client, 1, 1, test_hash1, test_dir)
pieces = [piece0, piece1]
piece_queue = PieceQueue(pieces)
test_piece = piece_queue.get_next_random()
# print test_piece.index
# print pieces[test_piece.index].index
self.assertEqual(test_piece.index, pieces[test_piece.index].index)
def setup_pieces(self, length, hash_bytes):
hash_list = self.process_raw_hash_list(hash_bytes, 20)
logging.info('setting up pieces for file length, %s', length)
pieces = []
self.num_pieces = len(hash_list)
logging.info('dividing up file into %s pieces', self.num_pieces)
self.bitfield = BitArray(self.num_pieces)
last_piece_length = self.file_length - (self.num_pieces - 1) * length
for i in range(self.num_pieces):
if i == self.num_pieces - 1:
length = last_piece_length
pieces.append(Piece(self, i, length, hash_list[i], self.dload_dir))
self.pieces = pieces
self.piece_queue = PieceQueue(pieces)
class Client(object):
def __init__(self, torrent):
self.torrent = torrent
self.torrent_state = 'random'
self.reactor = Reactor()
self.reactor_activated = False
self.peer_id = '-TZ-0000-00000000000'
self.peers = []
self.decode_torrent_and_setup_pieces()
self.handshake = self.build_handshake()
self.setup_tracker()
self.stitcher = Stitcher(self)
self.setup_peers()
def decode_torrent_and_setup_pieces(self):
f = open(self.torrent, 'r')
metainfo = B.bdecode(f.read())
data = metainfo['info'] # Un-bencoded dictionary
self.info_hash = H.sha1(B.bencode(data)).digest()
self.announce_url = self.find_http_announce_url(metainfo)
#self.announce_url = 'http://tracker.ccc.de:6969/announce'
self.file_name = data['name'] # Dir name if multi, otherwise file name
self.piece_length = data['piece length']
if 'files' in data: # Multifile torrent
self.setup_multi_file_info(data)
else:
self.setup_single_file_info(data)
self.setup_download_directory()
self.check_if_dload_file_exists()
self.setup_pieces(self.piece_length, data['pieces'])
def find_http_announce_url(self, metainfo):
print metainfo.keys()
# print metainfo['announce-list']
if self.is_http_url(metainfo['announce']):
return metainfo['announce']
elif 'announce-list' in metainfo.keys():
for url in metainfo['announce-list']:
url = url[0]
if self.is_http_url(url):
print url
return url
raise SystemExit('UDP announce urls are not supported. Currently only HTTP is supported.')
def is_http_url(self, url):
return 'http://' in url
def setup_multi_file_info(self, metainfo):
self.is_multi_file = True
self.files = metainfo['files'] # dictionary of file lengths + paths
self.file_length = sum([file_dict['length'] for file_dict in self.files]) # file_length = total # bytes to dload
def setup_single_file_info(self, metainfo):
self.is_multi_file = False
self.file_length = metainfo['length']
def build_handshake(self):
logging.info('Building handshake')
pstr = 'BitTorrent protocol'
handshake = struct.pack('B' + str(len(pstr)) + 's8x20s20s',
# 8x => reserved null bytes
len(pstr),
pstr,
self.info_hash,
self.peer_id
)
assert handshake != None
assert len(handshake) == 49 + len(pstr)
logging.info('Handshake constructed.')
return handshake
def setup_tracker(self):
self.tracker = Tracker(self, self.announce_url)
def setup_peers(self):
peer_ips = self.tracker.send_request_and_parse_response()
self.connect_to_peers(peer_ips)
def connect_to_peers(self, peer_tuples):
peers = [Peer(ip, port, self) for ip, port in peer_tuples]
logging.debug('Attempting to connect to peers %s', peer_tuples)
for peer in peers:
try:
if peer.ip == self.get_self_ip():
logging.info('Skipping peer; cannot connect to self')
continue
peer.connect()
peer_handshake = peer.send_and_receive_handshake(self.handshake)
logging.debug('Handshake returned.')
if peer.verify_handshake(peer_handshake, self.info_hash):
logging.debug('Handshake verified. Adding peer to peer list')
self.add_peer(peer)
if not self.reactor_activated:
self.activate_reactor()
self.reactor_activated = True
except IOError as e:
logging.warning('Error in construct_peers! %s', e)
self.manage_requests(5)
def get_self_ip(self):
# http://stackoverflow.com/questions/166506/finding-local-ip-addresses-using-pythons-stdlib/166520#166520
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(('8.8.8.8', 80))
ip = s.getsockname()[0]
s.close()
return ip
def add_peer(self, peer):
logging.info('Adding peer %s to peer list (in add_peer)', peer)
self.peers.append(peer)
self.reactor.add_peer_socket(peer)
def activate_reactor(self):
logging.debug('Activating reactor.')
self.reactor.get_data()
def process_raw_hash_list(self, hash_list, size):
tmp_hash = ''
piece_hashes = []
for char in hash_list:
if len(tmp_hash) < size:
tmp_hash = tmp_hash + char
else:
piece_hashes.append(tmp_hash)
tmp_hash = char
piece_hashes.append(tmp_hash)
return piece_hashes
def setup_pieces(self, length, hash_bytes):
hash_list = self.process_raw_hash_list(hash_bytes, 20)
logging.info('setting up pieces for file length, %s', length)
pieces = []
self.num_pieces = len(hash_list)
logging.info('dividing up file into %s pieces', self.num_pieces)
self.bitfield = BitArray(self.num_pieces)
last_piece_length = self.file_length - (self.num_pieces - 1) * length
for i in range(self.num_pieces):
if i == self.num_pieces - 1:
length = last_piece_length
pieces.append(Piece(self, i, length, hash_list[i], self.dload_dir))
self.pieces = pieces
self.piece_queue = PieceQueue(pieces)
def setup_download_directory(self):
dir_name = self.torrent
if dir_name.endswith('.torrent'):
dir_name = dir_name[:-8]
self.dload_dir = os.path.join(os.path.abspath(os.curdir), dir_name)
try:
os.makedirs(self.dload_dir)
except OSError:
if not os.path.isdir(self.dload_dir):
raise SystemExit('Cannot create directory to download torrent files into. Please check if a file named ' + dir_name + ' exists')
# raise OSError('Cannot create directory to download torrent files to.')
def check_if_dload_file_exists(self):
file_path = os.path.join(self.dload_dir, self.file_name)
if os.path.exists(file_path):
raise SystemExit('This file has already been downloaded.')
# Do something to cancel the rest of the setup
def add_piece_to_queue(self, piece):
self.piece_queue.put(piece)
def add_piece_to_bitfield(self, index):
if not self.bitfield[index]:
self.bitfield.invert(index)
self.manage_requests()
else:
logging.warning('Should never get save same piece more than once!')
def add_peer_to_piece_peer_list(self, piece_index, peer):
# print 'Adding piece', piece_index, 'to peer', peer
self.pieces[piece_index].add_peer_to_peer_list(peer)
def manage_requests(self, num_pieces=1):
logging.info('Sending more piece requests')
logging.info('Piece queue has %s pieces', self.piece_queue.length())
if not self.piece_queue.empty():
self.manage_piece_queue_state();
for i in xrange(num_pieces):
self.request_next_piece();
logging.info('Cleaning up piece queue')
else:
# Count outstanding requests to decide when to go into endgame
self.torrent_state = 'endgame'
self.start_endgame()
def start_endgame(self):
self.blasted_requests = []
for i in xrange(ENDGAME_MAX_BLASTS):
self.send_endgame_request()
def send_endgame_request(self):
block_info = self.select_outstanding_request()
if block_info:
self.blasted_requests.append(block_info)
self.pieces(block_info[0]).request_block_endgame(block_info)
def select_outstanding_request(self):
# TODO: Use filter instead of picking at random
peers_with_requests = filter(lambda peer: len(peer.outstanding_requests) > 0, self.peers)
if len(peers_with_requests):
peer = random.choice(peers_with_requests)
block_info = random.choice(peer.outstanding_requests)
return block_info
def manage_piece_queue_state(self):
# This should probably only get called occasionally
logging.debug('Have received %s pieces, need %s more', self.bitfield.count(1), self.bitfield.count(0))
if self.bitfield.count(1) > PIECE_THRESHOLD and self.piece_queue.length() > PIECE_THRESHOLD:
self.piece_queue.update_piece_order()
self.torrent_state = 'rarest_first'
# DISPATCHES TO PIECE
def request_block(self, block_info):
piece_index = block_info[0]
self.pieces[piece_index].request_block(block_info)
def request_next_piece(self):
next_piece = self.piece_queue.get_next_piece(self.torrent_state)
logging.info('Requesting piece %s', next_piece)
if next_piece:
try:
next_piece.request_all_blocks()
except IndexError as e:
self.piece_queue.put(next_piece)
logging.error(e)
def add_block(self, block_info, block):
(piece_index, begin, block_length) = block_info
logging.info('Writing block of length %s at index %s for piece %s',
block_length, begin, piece_index)
piece = self.pieces[piece_index]
logging.info('Piece has index %s', piece.index)
piece.add_block(begin, block)
self.tracker.update_download_stats(block_length)
if self.torrent_state == 'endgame' and block_info in self.blasted_requests:
piece = self.pieces[block_info[0]]
piece.cancel_block(block_info, self)
if self.bitfield.count(0) > 0:
self.send_endgame_request()
if self.num_pieces - self.bitfield.count(1) == 0:
self.finalize_download()
def finalize_download(self):
logging.info('Finalizing download')
if not self.tracker.is_download_complete():
raise SystemExit('Download didnt complete. Shutting down.')
self.stitch_files()
self.tracker.send_completed_msg_to_tracker_server()
logging.info('Shutting down connection with peers')
for peer in self.peers:
peer.close()
print 'Quitting client'
logging.info('Download completed. Quitting client.')
sys.exit()
def stitch_files(self):
print 'stitching...'
logging.info('Wrote all pieces, stitching them together')
self.stitcher.stitch()
logging.info('Stitching completed.')
def finalize_piece(self, piece):
if piece.check_info_hash():
logging.debug('Yay! Correct info hash!')
self.add_piece_to_bitfield(piece_index)
else:
logging.debug('Incorrect infohash, starting over with piece %s', piece_index)
piece.reset()
