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Viewing changes to bzrlib/merge3.py

  • Committer: Martin Pool
  • Date: 2005-07-06 04:09:02 UTC
  • Revision ID: mbp@sourcefrog.net-20050706040902-5b98f739e5ee1841
- avoid copying string lists when handling unmatched regions

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Lines of Context:
bzrlib/merge3.py
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        return None
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def compare_range(a, astart, aend, b, bstart, bend):
 
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    """Compare a[astart:aend] == b[bstart:bend], without slicing.
 
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    """
 
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    if (aend-astart) != (bend-bstart):
 
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        return False
 
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    for ia, ib in zip(xrange(astart, aend), xrange(bstart, bend)):
 
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        if a[ia] != b[ib]:
 
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            return False
 
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    else:
 
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        return True
 
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class Merge3(object):
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    """3-way merge of texts.
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            #print 'unmatched a=%d, b=%d' % (len_a, len_b)
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            if len_a or len_b:
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                lines_base = self.base[iz:zmatch]
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                lines_a = self.a[ia:amatch]
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                lines_b = self.b[ib:bmatch]
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                # we check the len just as a shortcut
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                equal_a = (len_a == len_base
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                           and lines_a == lines_base)
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                equal_b = (len_b == len_base
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                           and lines_b == lines_base)
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                same = (len_a == len_b
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                        and lines_a == lines_b)
 
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                # try to avoid actually slicing the lists
 
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                equal_a = compare_range(self.a, ia, amatch,
 
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                                        self.base, iz, zmatch)
 
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                equal_b = compare_range(self.b, ib, bmatch,
 
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                                        self.base, iz, zmatch)
 
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                same = compare_range(self.a, ia, amatch,
 
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                                     self.b, ib, bmatch)
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                if same:
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                    yield 'same', ia, amatch
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                elif not equal_a and not equal_b:
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                    yield 'conflict', iz, zmatch, ia, amatch, ib, bmatch
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                else:
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                    assert 0
 
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                    raise AssertionError("can't handle a=b=base but unmatched")
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                ia = amatch
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                ib = bmatch