lbry-sdk/lbry/file/file_manager.py

import asyncio
import logging
import typing
from typing import Optional
from aiohttp.web import Request
from lbry.error import ResolveError, DownloadMetadataTimeoutError, InsufficientFundsError
from lbry.error import ResolveTimeoutError, DownloadDataTimeoutError, KeyFeeAboveMaxAllowedError
from lbry.error import InvalidStreamURLError
from lbry.stream.managed_stream import ManagedStream
from lbry.torrent.torrent_manager import TorrentSource
from lbry.utils import cache_concurrent
from lbry.schema.url import URL
from lbry.wallet.dewies import dewies_to_lbc
from lbry.file.source_manager import SourceManager
from lbry.file.source import ManagedDownloadSource
from lbry.extras.daemon.storage import StoredContentClaim
if typing.TYPE_CHECKING:
    from lbry.conf import Config
    from lbry.extras.daemon.analytics import AnalyticsManager
    from lbry.extras.daemon.storage import SQLiteStorage
    from lbry.wallet import WalletManager
    from lbry.extras.daemon.exchange_rate_manager import ExchangeRateManager

log = logging.getLogger(__name__)


class FileManager:
    def __init__(self, loop: asyncio.AbstractEventLoop, config: 'Config', wallet_manager: 'WalletManager',
                 storage: 'SQLiteStorage', analytics_manager: Optional['AnalyticsManager'] = None):
        self.loop = loop
        self.config = config
        self.wallet_manager = wallet_manager
        self.storage = storage
        self.analytics_manager = analytics_manager
        self.source_managers: typing.Dict[str, SourceManager] = {}
        self.started = asyncio.Event()

    @property
    def streams(self):
        return self.source_managers['stream']._sources

    async def create_stream(self, file_path: str, key: Optional[bytes] = None, **kwargs) -> ManagedDownloadSource:
        if 'stream' in self.source_managers:
            return await self.source_managers['stream'].create(file_path, key, **kwargs)
        raise NotImplementedError

    async def start(self):
        await asyncio.gather(*(source_manager.start() for source_manager in self.source_managers.values()))
        for manager in self.source_managers.values():
            await manager.started.wait()
        self.started.set()

    def stop(self):
        for manager in self.source_managers.values():
            # fixme: pop or not?
            manager.stop()
        self.started.clear()

    @cache_concurrent
    async def download_from_uri(self, uri, exchange_rate_manager: 'ExchangeRateManager',
                                timeout: Optional[float] = None, file_name: Optional[str] = None,
                                download_directory: Optional[str] = None,
                                save_file: Optional[bool] = None, resolve_timeout: float = 3.0,
                                wallet: Optional['Wallet'] = None) -> ManagedDownloadSource:

        wallet = wallet or self.wallet_manager.default_wallet
        timeout = timeout or self.config.download_timeout
        start_time = self.loop.time()
        resolved_time = None
        stream = None
        claim = None
        error = None
        outpoint = None
        if save_file is None:
            save_file = self.config.save_files
        if file_name and not save_file:
            save_file = True
        if save_file:
            download_directory = download_directory or self.config.download_dir
        else:
            download_directory = None

        payment = None
        try:
            # resolve the claim
            try:
                if not URL.parse(uri).has_stream:
                    raise InvalidStreamURLError(uri)
            except ValueError:
                raise InvalidStreamURLError(uri)
            try:
                resolved_result = await asyncio.wait_for(
                    self.wallet_manager.ledger.resolve(
                        wallet.accounts, [uri],
                        include_purchase_receipt=True,
                        include_is_my_output=True
                    ), resolve_timeout
                )
            except asyncio.TimeoutError:
                raise ResolveTimeoutError(uri)
            except Exception as err:
                if isinstance(err, asyncio.CancelledError):
                    raise
                log.exception("Unexpected error resolving stream:")
                raise ResolveError(f"Unexpected error resolving stream: {str(err)}")
            if 'error' in resolved_result:
                raise ResolveError(f"Unexpected error resolving uri for download: {resolved_result['error']}")
            if not resolved_result or uri not in resolved_result:
                raise ResolveError(f"Failed to resolve stream at '{uri}'")
            txo = resolved_result[uri]
            if isinstance(txo, dict):
                raise ResolveError(f"Failed to resolve stream at '{uri}': {txo}")
            claim = txo.claim
            outpoint = f"{txo.tx_ref.id}:{txo.position}"
            resolved_time = self.loop.time() - start_time
            await self.storage.save_claim_from_output(self.wallet_manager.ledger, txo)

            ####################
            # update or replace
            ####################

            if claim.stream.source.bt_infohash:
                source_manager = self.source_managers['torrent']
                existing = source_manager.get_filtered(bt_infohash=claim.stream.source.bt_infohash)
            elif claim.stream.source.sd_hash:
                source_manager = self.source_managers['stream']
                existing = source_manager.get_filtered(sd_hash=claim.stream.source.sd_hash)
            else:
                raise ResolveError(f"There is nothing to download at {uri} - Source is unknown or unset")

            # resume or update an existing stream, if the stream changed: download it and delete the old one after
            to_replace, updated_stream = None, None
            if existing and existing[0].claim_id != txo.claim_id:
                raise ResolveError(f"stream for {existing[0].claim_id} collides with existing download {txo.claim_id}")
            if existing:
                log.info("claim contains a metadata only update to a stream we have")
                if claim.stream.source.bt_infohash:
                    await self.storage.save_torrent_content_claim(
                        existing[0].identifier, outpoint, existing[0].torrent_length, existing[0].torrent_name
                    )
                    claim_info = await self.storage.get_content_claim_for_torrent(existing[0].identifier)
                    existing[0].set_claim(claim_info.as_dict() if claim_info else None, claim)
                else:
                    await self.storage.save_content_claim(
                        existing[0].stream_hash, outpoint
                    )
                    await source_manager._update_content_claim(existing[0])
                updated_stream = existing[0]
            else:
                existing_for_claim_id = self.get_filtered(claim_id=txo.claim_id)
                if existing_for_claim_id:
                    log.info("claim contains an update to a stream we have, downloading it")
                    if save_file and existing_for_claim_id[0].output_file_exists:
                        save_file = False
                    if not claim.stream.source.bt_infohash:
                        existing_for_claim_id[0].downloader.node = source_manager.node
                    await existing_for_claim_id[0].start(timeout=timeout, save_now=save_file)
                    if not existing_for_claim_id[0].output_file_exists and (
                            save_file or file_name or download_directory):
                        await existing_for_claim_id[0].save_file(
                            file_name=file_name, download_directory=download_directory
                        )
                    to_replace = existing_for_claim_id[0]

            # resume or update an existing stream, if the stream changed: download it and delete the old one after
            if updated_stream:
                log.info("already have stream for %s", uri)
                if save_file and updated_stream.output_file_exists:
                    save_file = False
                if not claim.stream.source.bt_infohash:
                    updated_stream.downloader.node = source_manager.node
                await updated_stream.start(timeout=timeout, save_now=save_file)
                if not updated_stream.output_file_exists and (save_file or file_name or download_directory):
                    await updated_stream.save_file(
                        file_name=file_name, download_directory=download_directory
                    )
                return updated_stream

            ####################
            # pay fee
            ####################

            needs_purchasing = (
                not to_replace and
                not txo.is_my_output and
                txo.has_price and
                not txo.purchase_receipt
            )

            if needs_purchasing:
                payment = await self.wallet_manager.create_purchase_transaction(
                    wallet.accounts, txo, exchange_rate_manager
                )

            ####################
            # make downloader and wait for start
            ####################
            # temporary with fields we know so downloader can start. Missing fields are populated later.
            stored_claim = StoredContentClaim(outpoint=outpoint, claim_id=txo.claim_id, name=txo.claim_name,
                                              amount=txo.amount, height=txo.tx_ref.height,
                                              serialized=claim.to_bytes().hex())

            if not claim.stream.source.bt_infohash:
                # fixme: this shouldnt be here
                stream = ManagedStream(
                    self.loop, self.config, source_manager.blob_manager, claim.stream.source.sd_hash,
                    download_directory, file_name, ManagedStream.STATUS_RUNNING, content_fee=payment,
                    analytics_manager=self.analytics_manager, claim=stored_claim
                )
                stream.downloader.node = source_manager.node
            else:
                stream = TorrentSource(
                    self.loop, self.config, self.storage, identifier=claim.stream.source.bt_infohash,
                    file_name=file_name, download_directory=download_directory or self.config.download_dir,
                    status=ManagedStream.STATUS_RUNNING, claim=stored_claim, analytics_manager=self.analytics_manager,
                    torrent_session=source_manager.torrent_session
                )
            log.info("starting download for %s", uri)

            before_download = self.loop.time()
            await stream.start(timeout, save_file)

            ####################
            # success case: delete to_replace if applicable, broadcast fee payment
            ####################

            if to_replace:  # delete old stream now that the replacement has started downloading
                await source_manager.delete(to_replace)

            if payment is not None:
                await self.wallet_manager.broadcast_or_release(payment)
                payment = None  # to avoid releasing in `finally` later
                log.info("paid fee of %s for %s", dewies_to_lbc(stream.content_fee.outputs[0].amount), uri)
                await self.storage.save_content_fee(stream.stream_hash, stream.content_fee)

            source_manager.add(stream)

            if not claim.stream.source.bt_infohash:
                await self.storage.save_content_claim(stream.stream_hash, outpoint)
            else:
                await self.storage.save_torrent_content_claim(
                    stream.identifier, outpoint, stream.torrent_length, stream.torrent_name
                )
                claim_info = await self.storage.get_content_claim_for_torrent(stream.identifier)
                stream.set_claim(claim_info.as_dict() if claim_info else None, claim)
            if save_file:
                await asyncio.wait_for(stream.save_file(), timeout - (self.loop.time() - before_download))
            return stream
        except asyncio.TimeoutError:
            error = DownloadDataTimeoutError(stream.identifier)
            raise error
        except Exception as err:  # forgive data timeout, don't delete stream
            expected = (DownloadMetadataTimeoutError, DownloadDataTimeoutError, InsufficientFundsError,
                        KeyFeeAboveMaxAllowedError, ResolveError, InvalidStreamURLError)
            if isinstance(err, expected):
                log.warning("Failed to download %s: %s", uri, str(err))
            elif isinstance(err, asyncio.CancelledError):
                pass
            else:
                log.exception("Unexpected error downloading stream:")
            error = err
            raise
        finally:
            if payment is not None:
                # payment is set to None after broadcasting, if we're here an exception probably happened
                await self.wallet_manager.ledger.release_tx(payment)
            if self.analytics_manager and claim and claim.stream.source.bt_infohash:
                # TODO: analytics for torrents
                pass
            elif self.analytics_manager and (error or (stream and (stream.downloader.time_to_descriptor or
                                                                   stream.downloader.time_to_first_bytes))):
                server = self.wallet_manager.ledger.network.client.server
                self.loop.create_task(
                    self.analytics_manager.send_time_to_first_bytes(
                        resolved_time, self.loop.time() - start_time, None if not stream else stream.download_id,
                        uri, outpoint,
                        None if not stream else len(stream.downloader.blob_downloader.active_connections),
                        None if not stream else len(stream.downloader.blob_downloader.scores),
                        None if not stream else len(stream.downloader.blob_downloader.connection_failures),
                        False if not stream else stream.downloader.added_fixed_peers,
                        self.config.fixed_peer_delay if not stream else stream.downloader.fixed_peers_delay,
                        None if not stream else stream.sd_hash,
                        None if not stream else stream.downloader.time_to_descriptor,
                        None if not (stream and stream.descriptor) else stream.descriptor.blobs[0].blob_hash,
                        None if not (stream and stream.descriptor) else stream.descriptor.blobs[0].length,
                        None if not stream else stream.downloader.time_to_first_bytes,
                        None if not error else error.__class__.__name__,
                        None if not error else str(error),
                        None if not server else f"{server[0]}:{server[1]}"
                    )
                )

    async def stream_partial_content(self, request: Request, identifier: str):
        for source_manager in self.source_managers.values():
            if source_manager.get_filtered(identifier=identifier):
                return await source_manager.stream_partial_content(request, identifier)

    def get_filtered(self, *args, **kwargs) -> typing.List[ManagedDownloadSource]:
        """
        Get a list of filtered and sorted ManagedDownloadSource objects from all available source managers
        """
        result = last_error = None
        for manager in self.source_managers.values():
            try:
                result = (result or []) + manager.get_filtered(*args, **kwargs)
            except ValueError as error:
                last_error = error
        if result is not None:
            return result
        raise last_error

    async def delete(self, source: ManagedDownloadSource, delete_file=False):
        for manager in self.source_managers.values():
            await manager.delete(source, delete_file)