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  • Committer: John Arbash Meinel
  • Date: 2009-04-22 17:18:45 UTC
  • mto: This revision was merged to the branch mainline in revision 4301.
  • Revision ID: john@arbash-meinel.com-20090422171845-5dmqokv8ygf3cvs5
Add the ability to convert a gc block into 'human readable' form.

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bzrlib/groupcompress.py
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                 ]
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        return ''.join(chunks)
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    def _dump(self, include_text=False):
 
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        """Take this block, and spit out a human-readable structure.
 
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        :param include_text: Inserts also include text bits, chose whether you
 
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            want this displayed in the dump or not.
 
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        :return: A dump of the given block. The layout is something like:
 
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            [('f', length), ('d', delta_length, text_length, [delta_info])]
 
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            delta_info := [('i', num_bytes, text), ('c', offset, num_bytes),
 
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            ...]
 
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        """
 
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        self._ensure_content()
 
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        result = []
 
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        pos = 0
 
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        while pos < self._content_length:
 
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            kind = self._content[pos]
 
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            pos += 1
 
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            if kind not in ('f', 'd'):
 
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                raise ValueError('invalid kind character: %r' % (kind,))
 
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            content_len, len_len = decode_base128_int(
 
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                                self._content[pos:pos + 5])
 
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            pos += len_len
 
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            if content_len + pos > self._content_length:
 
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                raise ValueError('invalid content_len %d for record @ pos %d'
 
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                                 % (content_len, pos - len_len - 1))
 
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            if kind == 'f': # Fulltext
 
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                result.append(('f', content_len))
 
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            elif kind == 'd': # Delta
 
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                delta_content = self._content[pos:pos+content_len]
 
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                delta_info = []
 
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                # The first entry in a delta is the decompressed length
 
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                decomp_len, delta_pos = decode_base128_int(delta_content)
 
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                result.append(('d', content_len, decomp_len, delta_info))
 
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                measured_len = 0
 
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                while delta_pos < content_len:
 
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                    c = ord(delta_content[delta_pos])
 
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                    delta_pos += 1
 
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                    if c & 0x80: # Copy
 
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                        (offset, length,
 
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                         delta_pos) = decode_copy_instruction(delta_content, c,
 
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                                                              delta_pos)
 
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                        delta_info.append(('c', offset, length))
 
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                        measured_len += length
 
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                    else: # Insert
 
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                        if include_text:
 
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                            txt = delta_content[delta_pos:delta_pos+c]
 
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                        else:
 
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                            txt = ''
 
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                        delta_info.append(('i', c, txt))
 
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                        measured_len += c
 
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                        delta_pos += c
 
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                if delta_pos != content_len:
 
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                    raise ValueError('Delta consumed a bad number of bytes:'
 
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                                     ' %d != %d' % (delta_pos, content_len))
 
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                if measured_len != decomp_len:
 
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                    raise ValueError('Delta claimed fulltext was %d bytes, but'
 
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                                     ' extraction resulted in %d bytes'
 
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                                     % (decomp_len, measured_len))
 
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            pos += content_len
 
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        return result
 
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class _LazyGroupCompressFactory(object):
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    """Yield content from a GroupCompressBlock on demand."""
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    apply_delta_to_source,
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    encode_base128_int,
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    decode_base128_int,
 
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    decode_copy_instruction,
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    LinesDeltaIndex,
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    )
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try: