import asyncio import binascii import os import logging import random from hashlib import sha1 from tempfile import mkdtemp from typing import Optional, Tuple import libtorrent log = logging.getLogger(__name__) DEFAULT_FLAGS = ( # fixme: somehow the logic here is inverted? libtorrent.add_torrent_params_flags_t.flag_auto_managed | libtorrent.add_torrent_params_flags_t.flag_update_subscribe | libtorrent.add_torrent_params_flags_t.flag_sequential_download | libtorrent.add_torrent_params_flags_t.flag_paused ) class TorrentHandle: def __init__(self, loop, executor, handle): self._loop = loop self._executor = executor self._handle: libtorrent.torrent_handle = handle self.started = asyncio.Event(loop=loop) self.finished = asyncio.Event(loop=loop) self.metadata_completed = asyncio.Event(loop=loop) self.size = 0 self.total_wanted_done = 0 self.name = '' self.tasks = [] self._torrent_info: libtorrent.torrent_info = handle.torrent_file() self._base_path = None @property def torrent_file(self) -> Optional[libtorrent.file_storage]: return self._torrent_info.files() @property def largest_file(self) -> Optional[str]: if self.torrent_file is None: return None index = self.largest_file_index return os.path.join(self._base_path, self.torrent_file.file_path(index)) @property def save_path(self) -> Optional[str]: return self._base_path @property def largest_file_index(self): largest_size, index = 0, 0 for file_num in range(self.torrent_file.num_files()): if self.torrent_file.file_size(file_num) > largest_size: largest_size = self.torrent_file.file_size(file_num) index = file_num return index def stop_tasks(self): while self.tasks: self.tasks.pop().cancel() def byte_range_to_piece_range( self, file_index, start_offset, end_offset) -> Tuple[libtorrent.peer_request, libtorrent.peer_request]: start_piece = self._torrent_info.map_file(file_index, start_offset, 0) end_piece = self._torrent_info.map_file(file_index, end_offset, 0) return start_piece, end_piece async def stream_range_as_completed(self, file_index, start, end): first_piece, final_piece = self.byte_range_to_piece_range(file_index, start, end) start_piece_offset = final_piece.start piece_size = self._torrent_info.piece_length() log.info("Streaming torrent from piece %d to %d (bytes: %d -> %d): %s", first_piece.piece, final_piece.piece, start, end, self.name) self.prioritize(file_index, start, end) await self.resume() for piece_index in range(first_piece.piece, final_piece.piece + 1): while not self._handle.have_piece(piece_index): log.info("Waiting for piece %d: %s", piece_index, self.name) self._handle.set_piece_deadline(piece_index, 0) await asyncio.sleep(0.2) log.info("Streaming piece offset %d / %d for torrent %s", piece_index, final_piece.piece, self.name) yield piece_size - start_piece_offset def _show_status(self): # fixme: cleanup if not self._handle.is_valid(): return status = self._handle.status() self._base_path = status.save_path if status.has_metadata: self.size = status.total_wanted self.total_wanted_done = status.total_wanted_done self.name = status.name if not self.metadata_completed.is_set(): self.metadata_completed.set() self._torrent_info = self._handle.torrent_file() log.info("Metadata completed for btih:%s - %s", status.info_hash, self.name) # prioritize first 2mb self.prioritize(self.largest_file_index, 0, 2 * 1024 * 1024) first_piece = self.torrent_file.piece_index_at_file(self.largest_file_index) if not self.started.is_set(): if self._handle.have_piece(first_piece): log.debug("Got first piece, set started - %s", self.name) self.started.set() log.debug('%.2f%% complete (down: %.1f kB/s up: %.1f kB/s peers: %d seeds: %d) %s - %s', status.progress * 100, status.download_rate / 1000, status.upload_rate / 1000, status.num_peers, status.num_seeds, status.state, status.save_path) if (status.is_finished or status.is_seeding) and not self.finished.is_set(): self.finished.set() log.info("Torrent finished: %s", self.name) def prioritize(self, file_index, start, end, cleanup=False): first_piece, last_piece = self.byte_range_to_piece_range(file_index, start, end) priorities = self._handle.get_piece_priorities() priorities = [0 if cleanup else 1 for _ in priorities] self._handle.clear_piece_deadlines() for idx, piece_number in enumerate(range(first_piece.piece, last_piece.piece)): priorities[piece_number] = 7 - idx if 0 <= idx <= 6 else 1 self._handle.set_piece_deadline(piece_number, idx) log.debug("Prioritizing pieces for %s: %s", self.name, priorities) self._handle.prioritize_pieces(priorities) async def status_loop(self): while True: self._show_status() if self.finished.is_set(): break await asyncio.sleep(0.1) async def pause(self): await self._loop.run_in_executor( self._executor, self._handle.pause ) async def resume(self): await self._loop.run_in_executor( self._executor, lambda: self._handle.resume() # pylint: disable=unnecessary-lambda ) class TorrentSession: def __init__(self, loop, executor): self._loop = loop self._executor = executor self._session: Optional[libtorrent.session] = None self._handles = {} self.tasks = [] self.wait_start = True async def add_fake_torrent(self): tmpdir = mkdtemp() info, btih = _create_fake_torrent(tmpdir) flags = libtorrent.add_torrent_params_flags_t.flag_seed_mode handle = self._session.add_torrent({ 'ti': info, 'save_path': tmpdir, 'flags': flags }) self._handles[btih] = TorrentHandle(self._loop, self._executor, handle) return btih async def bind(self, interface: str = '0.0.0.0', port: int = 10889): settings = { 'listen_interfaces': f"{interface}:{port}", 'enable_natpmp': False, 'enable_upnp': False } self._session = await self._loop.run_in_executor( self._executor, libtorrent.session, settings # pylint: disable=c-extension-no-member ) self.tasks.append(self._loop.create_task(self.process_alerts())) def stop(self): while self.tasks: self.tasks.pop().cancel() self._session.save_state() self._session.pause() self._session.stop_dht() self._session.stop_lsd() self._session.stop_natpmp() self._session.stop_upnp() self._session = None def _pop_alerts(self): for alert in self._session.pop_alerts(): log.info("torrent alert: %s", alert) async def process_alerts(self): while True: await self._loop.run_in_executor( self._executor, self._pop_alerts ) await asyncio.sleep(1) async def pause(self): await self._loop.run_in_executor( self._executor, lambda: self._session.save_state() # pylint: disable=unnecessary-lambda ) await self._loop.run_in_executor( self._executor, lambda: self._session.pause() # pylint: disable=unnecessary-lambda ) async def resume(self): await self._loop.run_in_executor( self._executor, self._session.resume ) def _add_torrent(self, btih: str, download_directory: Optional[str]): params = {'info_hash': binascii.unhexlify(btih.encode()), 'flags': DEFAULT_FLAGS} if download_directory: params['save_path'] = download_directory handle = self._session.add_torrent(params) handle.force_dht_announce() self._handles[btih] = TorrentHandle(self._loop, self._executor, handle) def full_path(self, btih): return self._handles[btih].largest_file def save_path(self, btih): return self._handles[btih].save_path async def add_torrent(self, btih, download_path): await self._loop.run_in_executor( self._executor, self._add_torrent, btih, download_path ) self._handles[btih].tasks.append(self._loop.create_task(self._handles[btih].status_loop())) await self._handles[btih].metadata_completed.wait() if self.wait_start: # fixme: temporary until we add streaming support, otherwise playback fails! await self._handles[btih].started.wait() def remove_torrent(self, btih, remove_files=False): if btih in self._handles: handle = self._handles[btih] handle.stop_tasks() self._session.remove_torrent(handle._handle, 1 if remove_files else 0) self._handles.pop(btih) async def save_file(self, btih, download_directory): handle = self._handles[btih] await handle.resume() def get_size(self, btih): return self._handles[btih].size def get_name(self, btih): return self._handles[btih].name def get_downloaded(self, btih): return self._handles[btih].total_wanted_done def is_completed(self, btih): return self._handles[btih].finished.is_set() def stream_largest_file(self, btih, start, end): handle = self._handles[btih] return handle.stream_range_as_completed(handle.largest_file_index, start, end) def get_magnet_uri(btih): return f"magnet:?xt=urn:btih:{btih}" def _create_fake_torrent(tmpdir): # beware, that's just for testing path = os.path.join(tmpdir, 'tmp') with open(path, 'wb') as myfile: size = myfile.write(bytes([random.randint(0, 255) for _ in range(40)]) * 1024) file_storage = libtorrent.file_storage() file_storage.add_file('tmp', size) t = libtorrent.create_torrent(file_storage, 0, 4 * 1024 * 1024) libtorrent.set_piece_hashes(t, tmpdir) info = libtorrent.torrent_info(t.generate()) btih = sha1(info.metadata()).hexdigest() return info, btih async def main(): if os.path.exists("~/Downloads/ubuntu-18.04.3-live-server-amd64.torrent"): os.remove("~/Downloads/ubuntu-18.04.3-live-server-amd64.torrent") if os.path.exists("~/Downloads/ubuntu-18.04.3-live-server-amd64.iso"): os.remove("~/Downloads/ubuntu-18.04.3-live-server-amd64.iso") btih = "dd8255ecdc7ca55fb0bbf81323d87062db1f6d1c" executor = None session = TorrentSession(asyncio.get_event_loop(), executor) await session.bind() await session.add_torrent(btih, os.path.expanduser("~/Downloads")) while True: session.full_path(btih) await asyncio.sleep(1) await session.pause() executor.shutdown() if __name__ == "__main__": logging.basicConfig(level=logging.DEBUG, format="%(asctime)s %(levelname)-4s %(name)s:%(lineno)d: %(message)s") log = logging.getLogger(__name__) asyncio.run(main())