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  • Committer: Robert Collins
  • Date: 2007-08-02 02:18:17 UTC
  • mto: (2592.3.65 repository)
  • mto: This revision was merged to the branch mainline in revision 2667.
  • Revision ID: robertc@robertcollins.net-20070802021817-n8a86kevyvk2f9jo
* ``bzrlib.pack.ContainerWriter`` now returns an offset, length tuple to
  callers when inserting data, allowing generation of readv style access
  during pack creation, without needing a separate pass across the output
  pack to gather such details. (Robert Collins)

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bzrlib/pack.py
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        :param write_func: a callable that will be called when this
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            ContainerWriter needs to write some bytes.
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        """
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        self.write_func = write_func
 
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        self._write_func = write_func
 
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        self.current_offset = 0
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    def begin(self):
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        """Begin writing a container."""
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        self.write_func(FORMAT_ONE + "\n")
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    def write_func(self, bytes):
 
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        self._write_func(bytes)
 
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        self.current_offset += len(bytes)
 
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    def end(self):
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        """Finish writing a container."""
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        self.write_func("E")
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    def add_bytes_record(self, bytes, names):
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        """Add a Bytes record with the given names."""
 
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        """Add a Bytes record with the given names.
 
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        :param bytes: The bytes to insert.
 
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        :param names: The names to give the inserted bytes.
 
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        :return: An offset, length tuple. The offset is the offset
 
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            of the record within the container, and the length is the
 
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            length of data that will need to be read to reconstitute the
 
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            record. These offset and length can only be used with the pack
 
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            interface - they might be offset by headers or other such details
 
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            and thus are only suitable for use by a ContainerReader.
 
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        """
 
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        current_offset = self.current_offset
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        # Kind marker
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        self.write_func("B")
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        # Length
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        self.write_func("\n")
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        # Finally, the contents.
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        self.write_func(bytes)
 
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        # return a memo of where we wrote data to allow random access.
 
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        return current_offset, self.current_offset - current_offset
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class BaseReader(object):