lbry-sdk/lbry/stream/managed_stream.py
2022-03-08 20:40:09 -05:00

433 lines
20 KiB
Python

import os
import asyncio
import time
import typing
import logging
from typing import Optional
from aiohttp.web import Request, StreamResponse, HTTPRequestRangeNotSatisfiable
from lbry.error import DownloadSDTimeoutError
from scribe.schema.mime_types import guess_media_type
from lbry.stream.downloader import StreamDownloader
from lbry.stream.descriptor import StreamDescriptor, sanitize_file_name
from lbry.stream.reflector.client import StreamReflectorClient
from lbry.extras.daemon.storage import StoredContentClaim
from lbry.blob import MAX_BLOB_SIZE
from lbry.file.source import ManagedDownloadSource
if typing.TYPE_CHECKING:
from lbry.conf import Config
from scribe.schema.claim import Claim
from lbry.blob.blob_manager import BlobManager
from lbry.blob.blob_info import BlobInfo
from lbry.dht.node import Node
from lbry.extras.daemon.analytics import AnalyticsManager
from lbry.wallet.transaction import Transaction
log = logging.getLogger(__name__)
def _get_next_available_file_name(download_directory: str, file_name: str) -> str:
base_name, ext = os.path.splitext(os.path.basename(file_name))
i = 0
while os.path.isfile(os.path.join(download_directory, file_name)):
i += 1
file_name = "%s_%i%s" % (base_name, i, ext)
return file_name
async def get_next_available_file_name(loop: asyncio.AbstractEventLoop, download_directory: str, file_name: str) -> str:
return await loop.run_in_executor(None, _get_next_available_file_name, download_directory, file_name)
class ManagedStream(ManagedDownloadSource):
def __init__(self, loop: asyncio.AbstractEventLoop, config: 'Config', blob_manager: 'BlobManager',
sd_hash: str, download_directory: Optional[str] = None, file_name: Optional[str] = None,
status: Optional[str] = ManagedDownloadSource.STATUS_STOPPED,
claim: Optional[StoredContentClaim] = None,
download_id: Optional[str] = None, rowid: Optional[int] = None,
descriptor: Optional[StreamDescriptor] = None,
content_fee: Optional['Transaction'] = None,
analytics_manager: Optional['AnalyticsManager'] = None,
added_on: Optional[int] = None):
super().__init__(loop, config, blob_manager.storage, sd_hash, file_name, download_directory, status, claim,
download_id, rowid, content_fee, analytics_manager, added_on)
self.blob_manager = blob_manager
self.purchase_receipt = None
self.downloader = StreamDownloader(self.loop, self.config, self.blob_manager, sd_hash, descriptor)
self.analytics_manager = analytics_manager
self.reflector_progress = 0
self.uploading_to_reflector = False
self.file_output_task: typing.Optional[asyncio.Task] = None
self.delayed_stop_task: typing.Optional[asyncio.Task] = None
self.streaming_responses: typing.List[typing.Tuple[Request, StreamResponse]] = []
self.fully_reflected = asyncio.Event(loop=self.loop)
self.streaming = asyncio.Event(loop=self.loop)
self._running = asyncio.Event(loop=self.loop)
@property
def sd_hash(self) -> str:
return self.identifier
@property
def is_fully_reflected(self) -> bool:
return self.fully_reflected.is_set()
@property
def descriptor(self) -> StreamDescriptor:
return self.downloader.descriptor
@property
def stream_hash(self) -> str:
return self.descriptor.stream_hash
@property
def file_name(self) -> Optional[str]:
return self._file_name or (self.descriptor.suggested_file_name if self.descriptor else None)
@property
def written_bytes(self) -> int:
return 0 if not self.output_file_exists else os.stat(self.full_path).st_size
@property
def completed(self):
return self.written_bytes >= self.descriptor.lower_bound_decrypted_length()
@property
def stream_url(self):
return f"http://{self.config.streaming_host}:{self.config.streaming_port}/stream/{self.sd_hash}"
async def update_status(self, status: str):
assert status in [self.STATUS_RUNNING, self.STATUS_STOPPED, self.STATUS_FINISHED]
self._status = status
await self.blob_manager.storage.change_file_status(self.stream_hash, status)
@property
def blobs_completed(self) -> int:
return sum([1 if b.blob_hash in self.blob_manager.completed_blob_hashes else 0
for b in self.descriptor.blobs[:-1]])
@property
def blobs_in_stream(self) -> int:
return len(self.descriptor.blobs) - 1
@property
def blobs_remaining(self) -> int:
return self.blobs_in_stream - self.blobs_completed
@property
def mime_type(self):
return guess_media_type(os.path.basename(self.descriptor.suggested_file_name))[0]
@property
def download_path(self):
return f"{self.download_directory}/{self._file_name}" if self.download_directory and self._file_name else None
# @classmethod
# async def create(cls, loop: asyncio.AbstractEventLoop, config: 'Config',
# file_path: str, key: Optional[bytes] = None,
# iv_generator: Optional[typing.Generator[bytes, None, None]] = None) -> 'ManagedDownloadSource':
# """
# Generate a stream from a file and save it to the db
# """
# descriptor = await StreamDescriptor.create_stream(
# loop, blob_manager.blob_dir, file_path, key=key, iv_generator=iv_generator,
# blob_completed_callback=blob_manager.blob_completed
# )
# await blob_manager.storage.store_stream(
# blob_manager.get_blob(descriptor.sd_hash), descriptor
# )
# row_id = await blob_manager.storage.save_published_file(descriptor.stream_hash, os.path.basename(file_path),
# os.path.dirname(file_path), 0)
# return cls(loop, config, blob_manager, descriptor.sd_hash, os.path.dirname(file_path),
# os.path.basename(file_path), status=cls.STATUS_FINISHED, rowid=row_id, descriptor=descriptor)
async def start(self, timeout: Optional[float] = None,
save_now: bool = False):
timeout = timeout or self.config.download_timeout
if self._running.is_set():
return
log.info("start downloader for stream (sd hash: %s)", self.sd_hash)
self._running.set()
try:
await asyncio.wait_for(self.downloader.start(), timeout, loop=self.loop)
except asyncio.TimeoutError:
self._running.clear()
raise DownloadSDTimeoutError(self.sd_hash)
if self.delayed_stop_task and not self.delayed_stop_task.done():
self.delayed_stop_task.cancel()
self.delayed_stop_task = self.loop.create_task(self._delayed_stop())
if not await self.blob_manager.storage.file_exists(self.sd_hash):
if save_now:
if not self._file_name:
self._file_name = await get_next_available_file_name(
self.loop, self.download_directory,
self._file_name or sanitize_file_name(self.descriptor.suggested_file_name)
)
file_name, download_dir = self._file_name, self.download_directory
else:
file_name, download_dir = None, None
self._added_on = int(time.time())
self.rowid = await self.blob_manager.storage.save_downloaded_file(
self.stream_hash, file_name, download_dir, 0.0, added_on=self._added_on
)
if self.status != self.STATUS_RUNNING:
await self.update_status(self.STATUS_RUNNING)
async def stop(self, finished: bool = False):
"""
Stop any running save/stream tasks as well as the downloader and update the status in the database
"""
self.stop_tasks()
if (finished and self.status != self.STATUS_FINISHED) or self.status == self.STATUS_RUNNING:
await self.update_status(self.STATUS_FINISHED if finished else self.STATUS_STOPPED)
async def _aiter_read_stream(self, start_blob_num: Optional[int] = 0, connection_id: int = 0)\
-> typing.AsyncIterator[typing.Tuple['BlobInfo', bytes]]:
if start_blob_num >= len(self.descriptor.blobs[:-1]):
raise IndexError(start_blob_num)
for i, blob_info in enumerate(self.descriptor.blobs[start_blob_num:-1]):
assert i + start_blob_num == blob_info.blob_num
if connection_id == self.STREAMING_ID:
decrypted = await self.downloader.cached_read_blob(blob_info)
else:
decrypted = await self.downloader.read_blob(blob_info, connection_id)
yield (blob_info, decrypted)
async def stream_file(self, request: Request) -> StreamResponse:
log.info("stream file to browser for lbry://%s#%s (sd hash %s...)", self.claim_name, self.claim_id,
self.sd_hash[:6])
headers, size, skip_blobs, first_blob_start_offset = self._prepare_range_response_headers(
request.headers.get('range', 'bytes=0-')
)
await self.start()
response = StreamResponse(
status=206,
headers=headers
)
await response.prepare(request)
self.streaming_responses.append((request, response))
self.streaming.set()
wrote = 0
try:
async for blob_info, decrypted in self._aiter_read_stream(skip_blobs, connection_id=self.STREAMING_ID):
if not wrote:
decrypted = decrypted[first_blob_start_offset:]
if (blob_info.blob_num == len(self.descriptor.blobs) - 2) or (len(decrypted) + wrote >= size):
decrypted += (b'\x00' * (size - len(decrypted) - wrote - (skip_blobs * (MAX_BLOB_SIZE - 1))))
log.debug("sending browser final blob (%i/%i)", blob_info.blob_num + 1,
len(self.descriptor.blobs) - 1)
await response.write_eof(decrypted)
else:
log.debug("sending browser blob (%i/%i)", blob_info.blob_num + 1, len(self.descriptor.blobs) - 1)
await response.write(decrypted)
wrote += len(decrypted)
log.info("sent browser %sblob %i/%i", "(final) " if response._eof_sent else "",
blob_info.blob_num + 1, len(self.descriptor.blobs) - 1)
if response._eof_sent:
break
return response
except ConnectionResetError:
log.warning("connection was reset after sending browser %i blob bytes", wrote)
raise asyncio.CancelledError("range request transport was reset")
finally:
response.force_close()
if (request, response) in self.streaming_responses:
self.streaming_responses.remove((request, response))
if not self.streaming_responses:
self.streaming.clear()
@staticmethod
def _write_decrypted_blob(output_path: str, data: bytes):
with open(output_path, 'ab') as handle:
handle.write(data)
handle.flush()
async def _save_file(self, output_path: str):
log.info("save file for lbry://%s#%s (sd hash %s...) -> %s", self.claim_name, self.claim_id, self.sd_hash[:6],
output_path)
self.saving.set()
self.finished_write_attempt.clear()
self.finished_writing.clear()
self.started_writing.clear()
try:
open(output_path, 'wb').close() # pylint: disable=consider-using-with
async for blob_info, decrypted in self._aiter_read_stream(connection_id=self.SAVING_ID):
log.info("write blob %i/%i", blob_info.blob_num + 1, len(self.descriptor.blobs) - 1)
await self.loop.run_in_executor(None, self._write_decrypted_blob, output_path, decrypted)
if not self.started_writing.is_set():
self.started_writing.set()
await self.update_status(ManagedStream.STATUS_FINISHED)
if self.analytics_manager:
self.loop.create_task(self.analytics_manager.send_download_finished(
self.download_id, self.claim_name, self.sd_hash
))
self.finished_writing.set()
log.info("finished saving file for lbry://%s#%s (sd hash %s...) -> %s", self.claim_name, self.claim_id,
self.sd_hash[:6], self.full_path)
await self.blob_manager.storage.set_saved_file(self.stream_hash)
except Exception as err:
if os.path.isfile(output_path):
log.warning("removing incomplete download %s for %s", output_path, self.sd_hash)
os.remove(output_path)
if isinstance(err, asyncio.TimeoutError):
self.downloader.stop()
await self.blob_manager.storage.change_file_download_dir_and_file_name(
self.stream_hash, None, None
)
self._file_name, self.download_directory = None, None
await self.blob_manager.storage.clear_saved_file(self.stream_hash)
await self.update_status(self.STATUS_STOPPED)
return
elif not isinstance(err, asyncio.CancelledError):
log.exception("unexpected error encountered writing file for stream %s", self.sd_hash)
raise err
finally:
self.saving.clear()
self.finished_write_attempt.set()
async def save_file(self, file_name: Optional[str] = None, download_directory: Optional[str] = None):
await self.start()
if self.file_output_task and not self.file_output_task.done(): # cancel an already running save task
self.file_output_task.cancel()
self.download_directory = download_directory or self.download_directory or self.config.download_dir
if not self.download_directory:
raise ValueError("no directory to download to")
if not (file_name or self._file_name or self.descriptor.suggested_file_name):
raise ValueError("no file name to download to")
if not os.path.isdir(self.download_directory):
log.warning("download directory '%s' does not exist, attempting to make it", self.download_directory)
os.mkdir(self.download_directory)
self._file_name = await get_next_available_file_name(
self.loop, self.download_directory,
file_name or self._file_name or sanitize_file_name(self.descriptor.suggested_file_name)
)
await self.blob_manager.storage.change_file_download_dir_and_file_name(
self.stream_hash, self.download_directory, self.file_name
)
await self.update_status(ManagedStream.STATUS_RUNNING)
self.file_output_task = self.loop.create_task(self._save_file(self.full_path))
try:
await asyncio.wait_for(self.started_writing.wait(), self.config.download_timeout, loop=self.loop)
except asyncio.TimeoutError:
log.warning("timeout starting to write data for lbry://%s#%s", self.claim_name, self.claim_id)
self.stop_tasks()
await self.update_status(ManagedStream.STATUS_STOPPED)
def stop_tasks(self):
if self.file_output_task and not self.file_output_task.done():
self.file_output_task.cancel()
self.file_output_task = None
while self.streaming_responses:
req, response = self.streaming_responses.pop()
response.force_close()
req.transport.close()
self.downloader.stop()
self._running.clear()
async def upload_to_reflector(self, host: str, port: int) -> typing.List[str]:
sent = []
protocol = StreamReflectorClient(self.blob_manager, self.descriptor)
try:
self.uploading_to_reflector = True
await self.loop.create_connection(lambda: protocol, host, port)
await protocol.send_handshake()
sent_sd, needed = await protocol.send_descriptor()
if sent_sd: # reflector needed the sd blob
sent.append(self.sd_hash)
if not sent_sd and not needed: # reflector already has the stream
if not self.fully_reflected.is_set():
self.fully_reflected.set()
await self.blob_manager.storage.update_reflected_stream(self.sd_hash, f"{host}:{port}")
return []
we_have = [
blob_hash for blob_hash in needed if blob_hash in self.blob_manager.completed_blob_hashes
]
log.info("we have %i/%i needed blobs needed by reflector for lbry://%s#%s", len(we_have), len(needed),
self.claim_name, self.claim_id)
for i, blob_hash in enumerate(we_have):
await protocol.send_blob(blob_hash)
sent.append(blob_hash)
self.reflector_progress = int((i + 1) / len(we_have) * 100)
except (asyncio.TimeoutError, ValueError):
return sent
except ConnectionError:
return sent
except (OSError, Exception) as err:
if isinstance(err, asyncio.CancelledError):
log.warning("stopped uploading %s#%s to reflector", self.claim_name, self.claim_id)
elif isinstance(err, OSError):
log.warning(
"stopped uploading %s#%s to reflector because blobs were deleted or moved", self.claim_name,
self.claim_id
)
else:
log.exception("unexpected error reflecting %s#%s", self.claim_name, self.claim_id)
return sent
finally:
if protocol.transport:
protocol.transport.close()
self.uploading_to_reflector = False
return sent
async def update_content_claim(self, claim_info: Optional[typing.Dict] = None):
if not claim_info:
claim_info = await self.blob_manager.storage.get_content_claim(self.stream_hash)
self.set_claim(claim_info, claim_info['value'])
async def _delayed_stop(self):
stalled_count = 0
while self._running.is_set():
if self.saving.is_set() or self.streaming.is_set():
stalled_count = 0
else:
stalled_count += 1
if stalled_count > 1:
log.info("stopping inactive download for lbry://%s#%s (%s...)", self.claim_name, self.claim_id,
self.sd_hash[:6])
await self.stop()
return
await asyncio.sleep(1, loop=self.loop)
def _prepare_range_response_headers(self, get_range: str) -> typing.Tuple[typing.Dict[str, str], int, int, int]:
if '=' in get_range:
get_range = get_range.split('=')[1]
start, end = get_range.split('-')
size = 0
for blob in self.descriptor.blobs[:-1]:
size += blob.length - 1
if self.stream_claim_info and self.stream_claim_info.claim.stream.source.size:
size_from_claim = int(self.stream_claim_info.claim.stream.source.size)
if not size_from_claim <= size <= size_from_claim + 16:
raise ValueError("claim contains implausible stream size")
log.debug("using stream size from claim")
size = size_from_claim
elif self.stream_claim_info:
log.debug("estimating stream size")
start = int(start)
if not 0 <= start < size:
raise HTTPRequestRangeNotSatisfiable()
end = int(end) if end else size - 1
if end >= size:
raise HTTPRequestRangeNotSatisfiable()
skip_blobs = start // (MAX_BLOB_SIZE - 2) # -2 because ... dont remember
skip = skip_blobs * (MAX_BLOB_SIZE - 1) # -1 because
skip_first_blob = start - skip
start = skip_first_blob + skip
final_size = end - start + 1
headers = {
'Accept-Ranges': 'bytes',
'Content-Range': f'bytes {start}-{end}/{size}',
'Content-Length': str(final_size),
'Content-Type': self.mime_type
}
return headers, size, skip_blobs, skip_first_blob