lbry-sdk/lbry/stream/managed_stream.py
2020-06-06 13:20:26 -04:00

529 lines
23 KiB
Python

import os
import asyncio
import time
import typing
import logging
import binascii
from aiohttp.web import Request, StreamResponse, HTTPRequestRangeNotSatisfiable
from lbry.utils import generate_id
from lbry.error import DownloadSDTimeoutError
from lbry.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.blob import MAX_BLOB_SIZE
if typing.TYPE_CHECKING:
from lbry.conf import Config
from lbry.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.blockchain.transaction import Transaction
log = logging.getLogger(__name__)
class StoredContentClaim:
pass
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:
STATUS_RUNNING = "running"
STATUS_STOPPED = "stopped"
STATUS_FINISHED = "finished"
SAVING_ID = 1
STREAMING_ID = 2
__slots__ = [
'loop',
'config',
'blob_manager',
'sd_hash',
'download_directory',
'_file_name',
'_added_on',
'_status',
'stream_claim_info',
'download_id',
'rowid',
'content_fee',
'purchase_receipt',
'downloader',
'analytics_manager',
'fully_reflected',
'file_output_task',
'delayed_stop_task',
'streaming_responses',
'streaming',
'_running',
'saving',
'finished_writing',
'started_writing',
'finished_write_attempt'
]
def __init__(self, loop: asyncio.AbstractEventLoop, config: 'Config', blob_manager: 'BlobManager',
sd_hash: str, download_directory: typing.Optional[str] = None, file_name: typing.Optional[str] = None,
status: typing.Optional[str] = STATUS_STOPPED, claim: typing.Optional['StoredContentClaim'] = None,
download_id: typing.Optional[str] = None, rowid: typing.Optional[int] = None,
descriptor: typing.Optional[StreamDescriptor] = None,
content_fee: typing.Optional['Transaction'] = None,
analytics_manager: typing.Optional['AnalyticsManager'] = None,
added_on: typing.Optional[int] = None):
self.loop = loop
self.config = config
self.blob_manager = blob_manager
self.sd_hash = sd_hash
self.download_directory = download_directory
self._file_name = file_name
self._status = status
self.stream_claim_info = claim
self.download_id = download_id or binascii.hexlify(generate_id()).decode()
self.rowid = rowid
self.content_fee = content_fee
self.purchase_receipt = None
self._added_on = added_on
self.downloader = StreamDownloader(self.loop, self.config, self.blob_manager, sd_hash, descriptor)
self.analytics_manager = analytics_manager
self.fully_reflected = asyncio.Event(loop=self.loop)
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.streaming = asyncio.Event(loop=self.loop)
self._running = asyncio.Event(loop=self.loop)
self.saving = asyncio.Event(loop=self.loop)
self.finished_writing = asyncio.Event(loop=self.loop)
self.started_writing = asyncio.Event(loop=self.loop)
self.finished_write_attempt = asyncio.Event(loop=self.loop)
@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) -> typing.Optional[str]:
return self._file_name or (self.descriptor.suggested_file_name if self.descriptor else None)
@property
def added_on(self) -> typing.Optional[int]:
return self._added_on
@property
def status(self) -> str:
return self._status
@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 finished(self) -> bool:
return self.status == self.STATUS_FINISHED
@property
def running(self) -> bool:
return self.status == self.STATUS_RUNNING
@property
def claim_id(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.claim_id
@property
def txid(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.txid
@property
def nout(self) -> typing.Optional[int]:
return None if not self.stream_claim_info else self.stream_claim_info.nout
@property
def outpoint(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.outpoint
@property
def claim_height(self) -> typing.Optional[int]:
return None if not self.stream_claim_info else self.stream_claim_info.height
@property
def channel_claim_id(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.channel_claim_id
@property
def channel_name(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.channel_name
@property
def claim_name(self) -> typing.Optional[str]:
return None if not self.stream_claim_info else self.stream_claim_info.claim_name
@property
def metadata(self) -> typing.Optional[typing.Dict]:
return None if not self.stream_claim_info else self.stream_claim_info.claim.stream.to_dict()
@property
def metadata_protobuf(self) -> bytes:
if self.stream_claim_info:
return binascii.hexlify(self.stream_claim_info.claim.to_bytes())
@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 full_path(self) -> typing.Optional[str]:
return os.path.join(self.download_directory, os.path.basename(self.file_name)) \
if self.file_name and self.download_directory else None
@property
def output_file_exists(self):
return os.path.isfile(self.full_path) if self.full_path else False
@property
def mime_type(self):
return guess_media_type(os.path.basename(self.descriptor.suggested_file_name))[0]
@classmethod
async def create(cls, loop: asyncio.AbstractEventLoop, config: 'Config', blob_manager: 'BlobManager',
file_path: str, key: typing.Optional[bytes] = None,
iv_generator: typing.Optional[typing.Generator[bytes, None, None]] = None) -> 'ManagedStream':
"""
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, node: typing.Optional['Node'] = None, timeout: typing.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(node), 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:
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: typing.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, node: typing.Optional['Node'] = None) -> 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(node)
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(handle: typing.IO, data: bytes):
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:
with open(output_path, 'wb') as file_write_handle:
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, file_write_handle, 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: typing.Optional[str] = None, download_directory: typing.Optional[str] = None,
node: typing.Optional['Node'] = None):
await self.start(node)
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:
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 blob_hash in we_have:
await protocol.send_blob(blob_hash)
sent.append(blob_hash)
except (asyncio.TimeoutError, ValueError):
return sent
except ConnectionRefusedError:
return sent
finally:
if protocol.transport:
protocol.transport.close()
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 sent
def set_claim(self, claim_info: typing.Dict, claim: 'Claim'):
self.stream_claim_info = StoredContentClaim(
f"{claim_info['txid']}:{claim_info['nout']}", claim_info['claim_id'],
claim_info['name'], claim_info['amount'], claim_info['height'],
binascii.hexlify(claim.to_bytes()).decode(), claim.signing_channel_id, claim_info['address'],
claim_info['claim_sequence'], claim_info.get('channel_name')
)
async def update_content_claim(self, claim_info: typing.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