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50 lines
1.4 KiB
Python
50 lines
1.4 KiB
Python
"""
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This file defines a basic download-to-memory consumer, suitable for use in
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a filenode's read() method. See download_to_data() for an example of its use.
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Ported to Python 3.
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"""
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from __future__ import absolute_import
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from __future__ import division
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from __future__ import print_function
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from __future__ import unicode_literals
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from future.utils import PY2
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if PY2:
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from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min # noqa: F401
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from zope.interface import implementer
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from twisted.internet.interfaces import IConsumer
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@implementer(IConsumer)
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class MemoryConsumer(object):
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def __init__(self):
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self.chunks = []
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self.done = False
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def registerProducer(self, p, streaming):
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self.producer = p
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if streaming:
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# call resumeProducing once to start things off
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p.resumeProducing()
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else:
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while not self.done:
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p.resumeProducing()
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def write(self, data):
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self.chunks.append(data)
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def unregisterProducer(self):
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self.done = True
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def download_to_data(n, offset=0, size=None):
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"""
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Return Deferred that fires with results of reading from the given filenode.
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"""
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d = n.read(MemoryConsumer(), offset, size)
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d.addCallback(lambda mc: b"".join(mc.chunks))
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return d
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