312 lines
No EOL
15 KiB
Python
312 lines
No EOL
15 KiB
Python
from collections import defaultdict
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import logging
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from twisted.internet import defer
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from twisted.python.failure import Failure
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from zope.interface import implements
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from lbrynet.core.Error import PriceDisagreementError, DownloadCanceledError, InsufficientFundsError
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from lbrynet.core.Error import InvalidResponseError, RequestCanceledError, NoResponseError
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from lbrynet.core.Error import ConnectionClosedBeforeResponseError
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from lbrynet.core.client.ClientRequest import ClientRequest, ClientBlobRequest
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from lbrynet.interfaces import IRequestCreator
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class BlobRequester(object):
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implements(IRequestCreator)
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def __init__(self, blob_manager, peer_finder, payment_rate_manager, wallet, download_manager):
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self.blob_manager = blob_manager
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self.peer_finder = peer_finder
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self.payment_rate_manager = payment_rate_manager
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self.wallet = wallet
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self.download_manager = download_manager
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self._peers = defaultdict(int) # {Peer: score}
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self._available_blobs = defaultdict(list) # {Peer: [blob_hash]}
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self._unavailable_blobs = defaultdict(list) # {Peer: [blob_hash]}}
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self._protocol_prices = {} # {ClientProtocol: price}
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self._price_disagreements = [] # [Peer]
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self._incompatible_peers = []
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######## IRequestCreator #########
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def send_next_request(self, peer, protocol):
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sent_request = False
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if self._blobs_to_download() and self._should_send_request_to(peer):
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a_r = self._get_availability_request(peer)
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d_r = self._get_download_request(peer)
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p_r = None
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if a_r is not None or d_r is not None:
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p_r = self._get_price_request(peer, protocol)
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if a_r is not None:
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d1 = protocol.add_request(a_r)
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d1.addCallback(self._handle_availability, peer, a_r)
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d1.addErrback(self._request_failed, "availability request", peer)
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sent_request = True
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if d_r is not None:
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reserved_points = self._reserve_points(peer, protocol, d_r.max_pay_units)
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if reserved_points is not None:
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# Note: The following three callbacks will be called when the blob has been
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# fully downloaded or canceled
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d_r.finished_deferred.addCallbacks(self._download_succeeded, self._download_failed,
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callbackArgs=(peer, d_r.blob),
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errbackArgs=(peer,))
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d_r.finished_deferred.addBoth(self._pay_or_cancel_payment, protocol, reserved_points, d_r.blob)
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d_r.finished_deferred.addErrback(self._handle_download_error, peer, d_r.blob)
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d2 = protocol.add_blob_request(d_r)
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# Note: The following two callbacks will be called as soon as the peer sends its
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# response, which will be before the blob has finished downloading, but may be
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# after the blob has been canceled. For example,
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# 1) client sends request to Peer A
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# 2) the blob is finished downloading from peer B, and therefore this one is canceled
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# 3) client receives response from Peer A
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# Therefore, these callbacks shouldn't rely on there being a blob about to be
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# downloaded.
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d2.addCallback(self._handle_incoming_blob, peer, d_r)
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d2.addErrback(self._request_failed, "download request", peer)
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sent_request = True
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else:
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d_r.cancel(InsufficientFundsError())
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return defer.fail(InsufficientFundsError())
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if sent_request is True:
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if p_r is not None:
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d3 = protocol.add_request(p_r)
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d3.addCallback(self._handle_price_response, peer, p_r, protocol)
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d3.addErrback(self._request_failed, "price request", peer)
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return defer.succeed(sent_request)
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def get_new_peers(self):
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d = self._get_hash_for_peer_search()
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d.addCallback(self._find_peers_for_hash)
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return d
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######### internal calls #########
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def _download_succeeded(self, arg, peer, blob):
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logging.info("Blob %s has been successfully downloaded from %s", str(blob), str(peer))
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self._update_local_score(peer, 5.0)
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peer.update_stats('blobs_downloaded', 1)
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peer.update_score(5.0)
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self.blob_manager.blob_completed(blob)
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return arg
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def _download_failed(self, reason, peer):
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if not reason.check(DownloadCanceledError, PriceDisagreementError):
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self._update_local_score(peer, -10.0)
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return reason
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def _pay_or_cancel_payment(self, arg, protocol, reserved_points, blob):
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if blob.length != 0 and (not isinstance(arg, Failure) or arg.check(DownloadCanceledError)):
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self._pay_peer(protocol, blob.length, reserved_points)
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else:
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self._cancel_points(reserved_points)
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return arg
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def _handle_download_error(self, err, peer, blob_to_download):
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if not err.check(DownloadCanceledError, PriceDisagreementError, RequestCanceledError):
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logging.warning("An error occurred while downloading %s from %s. Error: %s",
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blob_to_download.blob_hash, str(peer), err.getTraceback())
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if err.check(PriceDisagreementError):
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# Don't kill the whole connection just because a price couldn't be agreed upon.
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# Other information might be desired by other request creators at a better rate.
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return True
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return err
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def _get_hash_for_peer_search(self):
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r = None
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blobs_to_download = self._blobs_to_download()
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if blobs_to_download:
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blobs_without_sources = self._blobs_without_sources()
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if not blobs_without_sources:
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blob_hash = blobs_to_download[0].blob_hash
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else:
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blob_hash = blobs_without_sources[0].blob_hash
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r = blob_hash
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logging.debug("Blob requester peer search response: %s", str(r))
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return defer.succeed(r)
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def _find_peers_for_hash(self, h):
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if h is None:
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return None
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else:
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d = self.peer_finder.find_peers_for_blob(h)
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def choose_best_peers(peers):
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bad_peers = self._get_bad_peers()
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return [p for p in peers if not p in bad_peers]
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d.addCallback(choose_best_peers)
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return d
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def _should_send_request_to(self, peer):
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if self._peers[peer] < -5.0:
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return False
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if peer in self._price_disagreements:
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return False
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if peer in self._incompatible_peers:
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return False
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return True
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def _get_bad_peers(self):
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return [p for p in self._peers.iterkeys() if not self._should_send_request_to(p)]
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def _hash_available(self, blob_hash):
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for peer in self._available_blobs:
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if blob_hash in self._available_blobs[peer]:
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return True
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return False
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def _hash_available_on(self, blob_hash, peer):
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if blob_hash in self._available_blobs[peer]:
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return True
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return False
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def _blobs_to_download(self):
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needed_blobs = self.download_manager.needed_blobs()
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return sorted(needed_blobs, key=lambda b: b.is_downloading())
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def _blobs_without_sources(self):
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return [b for b in self.download_manager.needed_blobs() if not self._hash_available(b.blob_hash)]
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def _get_availability_request(self, peer):
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all_needed = [b.blob_hash for b in self._blobs_to_download() if not b.blob_hash in self._available_blobs[peer]]
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# sort them so that the peer will be asked first for blobs it hasn't said it doesn't have
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to_request = sorted(all_needed, key=lambda b: b in self._unavailable_blobs[peer])[:20]
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if to_request:
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r_dict = {'requested_blobs': to_request}
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response_identifier = 'available_blobs'
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request = ClientRequest(r_dict, response_identifier)
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return request
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return None
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def _get_download_request(self, peer):
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request = None
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to_download = [b for b in self._blobs_to_download() if self._hash_available_on(b.blob_hash, peer)]
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while to_download and request is None:
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blob_to_download = to_download[0]
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to_download = to_download[1:]
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if not blob_to_download.is_validated():
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d, write_func, cancel_func = blob_to_download.open_for_writing(peer)
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def counting_write_func(data):
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peer.update_stats('blob_bytes_downloaded', len(data))
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return write_func(data)
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if d is not None:
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request_dict = {'requested_blob': blob_to_download.blob_hash}
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response_identifier = 'incoming_blob'
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request = ClientBlobRequest(request_dict, response_identifier, counting_write_func, d,
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cancel_func, blob_to_download)
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logging.info("Requesting blob %s from %s", str(blob_to_download), str(peer))
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return request
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def _price_settled(self, protocol):
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if protocol in self._protocol_prices:
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return True
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return False
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def _get_price_request(self, peer, protocol):
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request = None
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if not protocol in self._protocol_prices:
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self._protocol_prices[protocol] = self.payment_rate_manager.get_rate_blob_data(peer)
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request_dict = {'blob_data_payment_rate': self._protocol_prices[protocol]}
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request = ClientRequest(request_dict, 'blob_data_payment_rate')
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return request
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def _update_local_score(self, peer, amount):
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self._peers[peer] += amount
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def _reserve_points(self, peer, protocol, max_bytes):
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assert protocol in self._protocol_prices
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points_to_reserve = 1.0 * max_bytes * self._protocol_prices[protocol] / 2**20
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return self.wallet.reserve_points(peer, points_to_reserve)
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def _pay_peer(self, protocol, num_bytes, reserved_points):
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assert num_bytes != 0
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assert protocol in self._protocol_prices
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point_amount = 1.0 * num_bytes * self._protocol_prices[protocol] / 2**20
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self.wallet.send_points(reserved_points, point_amount)
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self.payment_rate_manager.record_points_paid(point_amount)
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def _cancel_points(self, reserved_points):
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self.wallet.cancel_point_reservation(reserved_points)
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def _handle_availability(self, response_dict, peer, request):
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if not request.response_identifier in response_dict:
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raise InvalidResponseError("response identifier not in response")
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logging.debug("Received a response to the availability request")
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blob_hashes = response_dict[request.response_identifier]
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for blob_hash in blob_hashes:
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if blob_hash in request.request_dict['requested_blobs']:
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logging.debug("The server has indicated it has the following blob available: %s", blob_hash)
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self._available_blobs[peer].append(blob_hash)
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if blob_hash in self._unavailable_blobs[peer]:
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self._unavailable_blobs[peer].remove(blob_hash)
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request.request_dict['requested_blobs'].remove(blob_hash)
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for blob_hash in request.request_dict['requested_blobs']:
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self._unavailable_blobs[peer].append(blob_hash)
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return True
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def _handle_incoming_blob(self, response_dict, peer, request):
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if not request.response_identifier in response_dict:
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return InvalidResponseError("response identifier not in response")
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if not type(response_dict[request.response_identifier]) == dict:
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return InvalidResponseError("response not a dict. got %s" %
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(type(response_dict[request.response_identifier]),))
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response = response_dict[request.response_identifier]
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if 'error' in response:
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# This means we're not getting our blob for some reason
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if response['error'] == "RATE_UNSET":
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# Stop the download with an error that won't penalize the peer
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request.cancel(PriceDisagreementError())
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else:
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# The peer has done something bad so we should get out of here
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return InvalidResponseError("Got an unknown error from the peer: %s" %
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(response['error'],))
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else:
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if not 'blob_hash' in response:
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return InvalidResponseError("Missing the required field 'blob_hash'")
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if not response['blob_hash'] == request.request_dict['requested_blob']:
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return InvalidResponseError("Incoming blob does not match expected. Incoming: %s. Expected: %s" %
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(response['blob_hash'], request.request_dict['requested_blob']))
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if not 'length' in response:
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return InvalidResponseError("Missing the required field 'length'")
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if not request.blob.set_length(response['length']):
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return InvalidResponseError("Could not set the length of the blob")
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return True
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def _handle_price_response(self, response_dict, peer, request, protocol):
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if not request.response_identifier in response_dict:
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return InvalidResponseError("response identifier not in response")
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assert protocol in self._protocol_prices
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response = response_dict[request.response_identifier]
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if response == "RATE_ACCEPTED":
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return True
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else:
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del self._protocol_prices[protocol]
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self._price_disagreements.append(peer)
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return True
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def _request_failed(self, reason, request_type, peer):
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if reason.check(RequestCanceledError):
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return
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if reason.check(NoResponseError):
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self._incompatible_peers.append(peer)
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return
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logging.warning("Blob requester: a request of type '%s' failed. Reason: %s, Error type: %s",
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str(request_type), reason.getErrorMessage(), reason.type)
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self._update_local_score(peer, -10.0)
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if isinstance(reason, InvalidResponseError):
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peer.update_score(-10.0)
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else:
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peer.update_score(-2.0)
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if reason.check(ConnectionClosedBeforeResponseError):
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return
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# Only unexpected errors should be returned, as they are indicative of real problems
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# and may be shown to the user.
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return reason |