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Viewing changes to groupcompress.py

  • Committer: John Arbash Meinel
  • Date: 2009-02-27 20:40:02 UTC
  • mto: (0.23.23 groupcompress_rabin)
  • mto: This revision was merged to the branch mainline in revision 4280.
  • Revision ID: john@arbash-meinel.com-20090227204002-fdzk52zc3frd4ddi
Insert a fulltext if the delta is more than half the total size.
Also, gcr deltas are more pithy, they probably are approx the same after
compression, but decrease the range limits since the copy instructions are
effectively pre-compressed.

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Lines of Context:
groupcompress.py
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        input_len = len(target_text)
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        new_chunks = ['label: %s\nsha1: %s\n' % (label, sha1)]
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        source_text = ''.join(self.lines)
 
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        # XXX: We have a few possibilities here. We could consider a few
 
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        #      different 'previous' windows, such as only the initial text, we
 
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        #      could do something with the 'just inserted' text
 
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        #      we could try a delta against whatever the last delta we
 
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        #      computed, (the idea being we just computed the delta_index, so
 
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        #      we re-use it here, and see if that is good enough, etc)
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        delta = _groupcompress_c.make_delta(source_text, target_text)
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        if delta is None:
 
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        if (delta is None
 
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            or len(delta) > len(target_text) / 2):
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            # We can't delta (perhaps source_text is empty)
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            # so mark this as an insert
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            new_chunks.insert(0, 'fulltext\n')
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                prefix = record.key[0]
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                if (last_prefix is not None and prefix != last_prefix):
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                    soft = True
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                    if basis_end > 1024 * 1024 * 4:
 
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                    if basis_end > 1024 * 1024 * 2:
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                        flush()
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                        self._compressor = GroupCompressor(self._delta)
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                        self._unadded_refs = {}
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            keys_to_add.append((key, '%d %d' % (basis_end, end_point),
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                (record.parents,)))
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            basis_end = end_point
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            if basis_end > 1024 * 1024 * 8:
 
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            if basis_end > 1024 * 1024 * 4:
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                flush()
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                self._compressor = GroupCompressor(self._delta)
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                self._unadded_refs = {}