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  • Committer: Bazaar Package Importer
  • Author(s): Matthias Klose
  • Date: 2007-01-17 14:52:35 UTC
  • mfrom: (1.1.5 upstream) (2.1.2 etch)
  • Revision ID: james.westby@ubuntu.com-20070117145235-btmig6qfmqfen0om
Tags: 2.5.0-0ubuntu1
New upstream version, compatible with python2.5.

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twisted/vfs/adapters/stream.py
 
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import os
 
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from zope.interface import implements
 
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from twisted.web2.stream import SimpleStream, IByteStream
 
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from twisted.vfs.ivfs import IFileSystemLeaf, VFSError
 
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from twisted.python import components
 
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class FileSystemLeafStream(SimpleStream):
 
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    implements(IByteStream)
 
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    """A stream that reads data from a FileSystemLeaf."""
 
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    # 65K, minus some slack
 
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    CHUNK_SIZE = 2 ** 2 ** 2 ** 2 - 32
 
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    def __init__(self, leaf, start=0, length=None):
 
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        """
 
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        Create the stream from leaf. If you specify start and length,
 
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        use only that portion of the leaf.
 
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        """
 
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        self.leaf = leaf
 
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        self.leaf.open(os.O_RDONLY)
 
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        self.start = start
 
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        if length is None:
 
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            self.length = leaf.getMetadata()['size']
 
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        else:
 
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            self.length = length
 
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    def read(self):
 
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        if self.leaf is None:
 
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            return None
 
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        length = self.length
 
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        if length == 0:
 
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            self.leaf = None
 
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            return None
 
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        readSize = min(length, self.CHUNK_SIZE)
 
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        b = self.leaf.readChunk(self.start, readSize)
 
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        bytesRead = len(b)
 
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        if bytesRead != readSize:
 
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            raise VFSError(
 
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                ("Ran out of data reading vfs leaf %r, expected %d more bytes,"
 
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                 " got %d") % (self.leaf, readSize, bytesRead))
 
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        else:
 
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            self.length -= bytesRead
 
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            self.start += bytesRead
 
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            return b
 
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    def close(self):
 
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        self.leaf.close()
 
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        self.leaf = None
 
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        SimpleStream.close(self)
 
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components.registerAdapter(FileSystemLeafStream, IFileSystemLeaf, IByteStream)