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  • Committer: Andrew Bennetts
  • Date: 2007-03-26 06:24:01 UTC
  • mto: This revision was merged to the branch mainline in revision 2376.
  • Revision ID: andrew.bennetts@canonical.com-20070326062401-k3nbefzje5332jaf
Deal with review comments from Robert:

  * Add my name to the NEWS file
  * Move the test case to a new module in branch_implementations
  * Remove revision_history cruft from identitymap and test_identitymap
  * Improve some docstrings

Also, this fixes a bug where revision_history was not returning a copy of the
cached data, allowing the cache to be corrupted.

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bzrlib/tuned_gzip.py
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# we want a \n preserved, break on \n only splitlines.
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import bzrlib
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__all__ = ["GzipFile", "bytes_to_gzip"]
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def bytes_to_gzip(bytes, factory=zlib.compressobj,
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    level=zlib.Z_DEFAULT_COMPRESSION, method=zlib.DEFLATED,
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    width=-zlib.MAX_WBITS, mem=zlib.DEF_MEM_LEVEL,
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    crc32=zlib.crc32):
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    """Create a gzip file containing bytes and return its content."""
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    result = [
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        '\037\213'  # self.fileobj.write('\037\213')  # magic header
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        '\010'      # self.fileobj.write('\010')      # compression method
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                    # fname = self.filename[:-3]
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                    # flags = 0
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                    # if fname:
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                    #     flags = FNAME
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        '\x00'      # self.fileobj.write(chr(flags))
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        '\0\0\0\0'  # write32u(self.fileobj, long(time.time()))
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        '\002'      # self.fileobj.write('\002')
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        '\377'      # self.fileobj.write('\377')
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                    # if fname:
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        ''          #     self.fileobj.write(fname + '\000')
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        ]
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    # using a compressobj avoids a small header and trailer that the compress()
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    # utility function adds.
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    compress = factory(level, method, width, mem, 0)
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    result.append(compress.compress(bytes))
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    result.append(compress.flush())
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    result.append(struct.pack("<L", LOWU32(crc32(bytes))))
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    # size may exceed 2GB, or even 4GB
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    result.append(struct.pack("<L", LOWU32(len(bytes))))
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    return ''.join(result)
 
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__all__ = ["GzipFile"]
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class GzipFile(gzip.GzipFile):
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        if buf == "":
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            self._add_read_data(self.decompress.flush())
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            if len(self.decompress.unused_data) < 8:
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                raise AssertionError("what does flush do?")
 
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            assert len(self.decompress.unused_data) >= 8, "what does flush do?"
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            self._gzip_tail = self.decompress.unused_data[0:8]
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            self._read_eof()
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            # tell the driving read() call we have stuffed all the data
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                self._gzip_tail = self.decompress.unused_data[0:8]
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            elif seek_length < 0:
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                # we haven't read enough to check the checksum.
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                if not (-8 < seek_length):
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                    raise AssertionError("too great a seek")
 
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                assert -8 < seek_length, "too great a seek."
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                buf = self.fileobj.read(-seek_length)
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                self._gzip_tail = self.decompress.unused_data + buf
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            else:
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        # We then check the that the computed CRC and size of the
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        # uncompressed data matches the stored values.  Note that the size
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        # stored is the true file size mod 2**32.
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        if not (len(self._gzip_tail) == 8):
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            raise AssertionError("gzip trailer is incorrect length.")
 
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        assert len(self._gzip_tail) == 8, "gzip trailer is incorrect length."
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        crc32, isize = struct.unpack("<LL", self._gzip_tail)
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        # note that isize is unsigned - it can exceed 2GB
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        if crc32 != U32(self.crc):