101 lines
3.3 KiB
Python
101 lines
3.3 KiB
Python
import logging
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from twisted.internet import defer
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log = logging.getLogger(__name__)
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class DownloadManager(object):
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#implements(interfaces.IDownloadManager)
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def __init__(self, blob_manager):
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self.blob_manager = blob_manager
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self.blob_info_finder = None
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self.progress_manager = None
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self.blob_handler = None
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self.connection_manager = None
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self.blobs = {}
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self.blob_infos = {}
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######### IDownloadManager #########
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def start_downloading(self):
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d = self.blob_info_finder.get_initial_blobs()
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log.debug("Requested the initial blobs from the info finder")
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d.addCallback(self.add_blobs_to_download)
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d.addCallback(lambda _: self.resume_downloading())
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return d
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@defer.inlineCallbacks
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def resume_downloading(self):
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yield self.connection_manager.start()
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yield self.progress_manager.start()
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defer.returnValue(True)
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@defer.inlineCallbacks
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def stop_downloading(self):
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yield self.progress_manager.stop()
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yield self.connection_manager.stop()
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defer.returnValue(True)
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def add_blobs_to_download(self, blob_infos):
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log.debug("Adding %s blobs to blobs", len(blob_infos))
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def add_blob_to_list(blob, blob_num):
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self.blobs[blob_num] = blob
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log.debug(
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"Added blob (hash: %s, number %s) to the list", blob.blob_hash, blob_num)
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def error_during_add(err):
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log.warning(
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"An error occurred adding the blob to blobs. Error:%s", err.getErrorMessage())
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return err
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ds = []
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for blob_info in blob_infos:
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if not blob_info.blob_num in self.blobs:
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self.blob_infos[blob_info.blob_num] = blob_info
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log.debug(
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"Trying to get the blob associated with blob hash %s", blob_info.blob_hash)
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d = self.blob_manager.get_blob(blob_info.blob_hash, blob_info.length)
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d.addCallback(add_blob_to_list, blob_info.blob_num)
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d.addErrback(error_during_add)
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ds.append(d)
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dl = defer.DeferredList(ds)
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return dl
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def stream_position(self):
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return self.progress_manager.stream_position()
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def needed_blobs(self):
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return self.progress_manager.needed_blobs()
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def final_blob_num(self):
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return self.blob_info_finder.final_blob_num()
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def handle_blob(self, blob_num):
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return self.blob_handler.handle_blob(self.blobs[blob_num], self.blob_infos[blob_num])
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def calculate_total_bytes(self):
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return sum([bi.length for bi in self.blob_infos.itervalues()])
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def calculate_bytes_left_to_output(self):
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if not self.blobs:
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return self.calculate_total_bytes()
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else:
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to_be_outputted = [
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b for n, b in self.blobs.iteritems()
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if n >= self.progress_manager.last_blob_outputted
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]
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return sum([b.length for b in to_be_outputted if b.length is not None])
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def calculate_bytes_left_to_download(self):
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if not self.blobs:
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return self.calculate_total_bytes()
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else:
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return sum([b.length for b in self.needed_blobs() if b.length is not None])
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def get_head_blob_hash(self):
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return self.blobs[0].blob_hash
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