lbry-sdk/lbrynet/lbrynet_daemon/Downloader.py
Job Evers-Meltzer 1151019186 Improve downloader error handling
Instead of having an error cause a timeout, send
the error directly to the callback
2017-01-13 08:24:05 -06:00

167 lines
7 KiB
Python

import logging
import os
from copy import deepcopy
from twisted.internet import defer
from twisted.internet.task import LoopingCall
from lbrynet.core.Error import InsufficientFundsError, KeyFeeAboveMaxAllowed
from lbrynet.core.StreamDescriptor import download_sd_blob
from lbrynet.metadata.Fee import FeeValidator
from lbrynet.lbryfilemanager.EncryptedFileDownloader import ManagedEncryptedFileDownloaderFactory
from lbrynet import conf
INITIALIZING_CODE = 'initializing'
DOWNLOAD_METADATA_CODE = 'downloading_metadata'
DOWNLOAD_TIMEOUT_CODE = 'timeout'
DOWNLOAD_RUNNING_CODE = 'running'
# TODO: is this ever used?
DOWNLOAD_STOPPED_CODE = 'stopped'
STREAM_STAGES = [
(INITIALIZING_CODE, 'Initializing'),
(DOWNLOAD_METADATA_CODE, 'Downloading metadata'),
(DOWNLOAD_RUNNING_CODE, 'Started stream'),
(DOWNLOAD_STOPPED_CODE, 'Paused stream'),
(DOWNLOAD_TIMEOUT_CODE, 'Stream timed out')
]
log = logging.getLogger(__name__)
class GetStream(object):
def __init__(self, sd_identifier, session, wallet,
lbry_file_manager, exchange_rate_manager,
max_key_fee, data_rate=0.5, timeout=None,
download_directory=None, file_name=None):
if timeout is None:
timeout = conf.settings.download_timeout
self.wallet = wallet
self.resolved_name = None
self.description = None
self.fee = None
self.data_rate = data_rate
self.file_name = file_name
self.session = session
self.exchange_rate_manager = exchange_rate_manager
self.payment_rate_manager = self.session.payment_rate_manager
self.lbry_file_manager = lbry_file_manager
self.sd_identifier = sd_identifier
self.sd_hash = None
self.max_key_fee = max_key_fee
self.stream_info = None
self.stream_info_manager = None
self._d = defer.Deferred(None)
self.timeout = timeout
self.timeout_counter = 0
self.download_directory = download_directory
self.download_path = None
self.downloader = None
# fired after the metadata has been downloaded and the
# actual file has been started
self.finished = defer.Deferred(None)
self.checker = LoopingCall(self.check_status)
self.code = STREAM_STAGES[0]
def check_status(self):
self.timeout_counter += 1
# download_path is set after the sd blob has been downloaded
if self.download_path:
self.checker.stop()
self.finished.callback((True, self.sd_hash, self.download_path))
elif self.timeout_counter >= self.timeout:
log.info("Timeout downloading lbry://%s" % self.resolved_name)
self.checker.stop()
self._d.cancel()
self.code = STREAM_STAGES[4]
self.finished.callback((False, None, None))
def _convert_max_fee(self):
max_fee = FeeValidator(self.max_key_fee)
if max_fee.currency_symbol == "LBC":
return max_fee.amount
return self.exchange_rate_manager.to_lbc(self.max_key_fee).amount
def start(self, stream_info, name):
def _cancel(err):
if self.checker:
self.checker.stop()
self.finished.errback(err)
def _set_status(x, status):
log.info("Download lbry://%s status changed to %s" % (self.resolved_name, status))
self.code = next(s for s in STREAM_STAGES if s[0] == status)
return x
def get_downloader_factory(metadata):
for factory in metadata.factories:
if isinstance(factory, ManagedEncryptedFileDownloaderFactory):
return factory, metadata
raise Exception('No suitable factory was found in {}'.format(metadata.factories))
def make_downloader(args):
factory, metadata = args
return factory.make_downloader(metadata,
[self.data_rate, True],
self.payment_rate_manager,
download_directory=self.download_directory,
file_name=self.file_name)
self.resolved_name = name
self.stream_info = deepcopy(stream_info)
self.description = self.stream_info['description']
self.sd_hash = self.stream_info['sources']['lbry_sd_hash']
if 'fee' in self.stream_info:
self.fee = FeeValidator(self.stream_info['fee'])
max_key_fee = self._convert_max_fee()
converted_fee = self.exchange_rate_manager.to_lbc(self.fee).amount
if converted_fee > self.wallet.wallet_balance:
msg = "Insufficient funds to download lbry://{}. Need {:0.2f}, have {:0.2f}".format(
self.resolved_name, converted_fee, self.wallet.wallet_balance)
raise InsufficientFundsError(msg)
if converted_fee > max_key_fee:
msg = "Key fee {:0.2f} above limit of {:0.2f} didn't download lbry://{}".format(
converted_fee, max_key_fee, self.resolved_name)
raise KeyFeeAboveMaxAllowed(msg)
log.info(
"Key fee %f below limit of %f, downloading lbry://%s",
converted_fee, max_key_fee, self.resolved_name)
self.checker.start(1)
self._d.addCallback(lambda _: _set_status(None, DOWNLOAD_METADATA_CODE))
self._d.addCallback(lambda _: download_sd_blob(
self.session, self.sd_hash, self.payment_rate_manager))
self._d.addCallback(self.sd_identifier.get_metadata_for_sd_blob)
self._d.addCallback(lambda r: _set_status(r, DOWNLOAD_RUNNING_CODE))
self._d.addCallback(get_downloader_factory)
self._d.addCallback(make_downloader)
self._d.addCallbacks(self._start_download, _cancel)
self._d.callback(None)
return self.finished
def _start_download(self, downloader):
log.info('Starting download for %s', self.resolved_name)
self.downloader = downloader
self.download_path = os.path.join(downloader.download_directory, downloader.file_name)
d = self._pay_key_fee()
d.addCallback(lambda _: log.info(
"Downloading %s --> %s", self.sd_hash, self.downloader.file_name))
d.addCallback(lambda _: self.downloader.start())
def _pay_key_fee(self):
if self.fee is not None:
fee_lbc = self.exchange_rate_manager.to_lbc(self.fee).amount
reserved_points = self.wallet.reserve_points(self.fee.address, fee_lbc)
if reserved_points is None:
log.warning('Unable to pay the key fee of %s for %s', fee_lbc, self.resolved_name)
# TODO: If we get here, nobody will know that there was an error
# as nobody actually cares about self._d
return defer.fail(InsufficientFundsError())
return self.wallet.send_points_to_address(reserved_points, fee_lbc)
return defer.succeed(None)