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# Copyright (C) 2005-2010 Canonical Ltd
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# Copyright (C) 2004, 2005 by Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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from __future__ import absolute_import
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# mbp: "you know that thing where cvs gives you conflict markers?"
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# s: "i hate that."
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class CantReprocessAndShowBase(errors.BzrError):
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_fmt = ("Can't reprocess and show base, because reprocessing obscures "
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"the relationship of conflicting lines to the base")
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from difflib import SequenceMatcher
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from bzrlib.errors import CantReprocessAndShowBase
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def intersect(ra, rb):
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"""Given two ranges return the range where they intersect or 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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if (aend - astart) != (bend - bstart):
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if (aend-astart) != (bend-bstart):
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for ia, ib in zip(range(astart, aend), range(bstart, bend)):
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for ia, ib in zip(xrange(astart, aend), xrange(bstart, bend)):
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class Merge3(object):
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Given BASE, OTHER, THIS, tries to produce a combined text
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incorporating the changes from both BASE->OTHER and BASE->THIS.
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All three will typically be sequences of lines."""
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def __init__(self, base, a, b, is_cherrypick=False, allow_objects=False):
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:param base: lines in BASE
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:param is_cherrypick: flag indicating if this merge is a cherrypick.
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When cherrypicking b => a, matches with b and base do not conflict.
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:param allow_objects: if True, do not require that base, a and b are
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plain Python strs. Also prevents BinaryFile from being raised.
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Lines can be any sequence of comparable and hashable Python
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textfile.check_text_lines(base)
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textfile.check_text_lines(a)
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textfile.check_text_lines(b)
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def __init__(self, base, a, b):
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self.is_cherrypick = is_cherrypick
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def merge_lines(self,
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start_marker=b'<<<<<<<',
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mid_marker=b'=======',
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end_marker=b'>>>>>>>',
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start_marker='<<<<<<<',
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"""Return merge in cvs-like form.
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if self.a[0].endswith(b'\r\n'):
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elif self.a[0].endswith(b'\r'):
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if base_marker and reprocess:
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raise CantReprocessAndShowBase()
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start_marker = start_marker + b' ' + name_a
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start_marker = start_marker + ' ' + name_a
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end_marker = end_marker + b' ' + name_b
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end_marker = end_marker + ' ' + name_b
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if name_base and base_marker:
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base_marker = base_marker + b' ' + name_base
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base_marker = base_marker + ' ' + name_base
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merge_regions = self.merge_regions()
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if reprocess is True:
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merge_regions = self.reprocess_merge_regions(merge_regions)
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for i in range(t[1], t[2]):
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elif what == 'conflict':
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yield start_marker + newline
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yield start_marker + '\n'
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for i in range(t[3], t[4]):
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if base_marker is not None:
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yield base_marker + newline
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yield base_marker + '\n'
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for i in range(t[1], t[2]):
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yield self.base[i]
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yield mid_marker + newline
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yield mid_marker + '\n'
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for i in range(t[5], t[6]):
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yield end_marker + newline
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yield end_marker + '\n'
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raise ValueError(what)
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def merge_annotated(self):
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"""Return merge with conflicts, showing origin of lines.
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Most useful for debugging merge.
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Most useful for debugging merge.
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for t in self.merge_regions():
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# section a[0:ia] has been disposed of, etc
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for zmatch, zend, amatch, aend, bmatch, bend in self.find_sync_regions():
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#print 'match base [%d:%d]' % (zmatch, zend)
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matchlen = zend - zmatch
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# matchlen == (aend - amatch)
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# matchlen == (bend - bmatch)
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assert matchlen == (aend - amatch)
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assert matchlen == (bend - bmatch)
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len_a = amatch - ia
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len_b = bmatch - ib
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len_base = zmatch - iz
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# print 'unmatched a=%d, b=%d' % (len_a, len_b)
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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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# 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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yield 'same', ia, amatch
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elif equal_a and not equal_b:
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yield 'b', ib, bmatch
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elif equal_b and not equal_a:
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yield 'a', 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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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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if equal_a and not equal_b:
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yield 'b', ib, bmatch
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elif equal_b and not equal_a:
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yield 'a', ia, amatch
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elif not equal_a and not equal_b:
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if self.is_cherrypick:
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for node in self._refine_cherrypick_conflict(
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iz, zmatch, ia, amatch,
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yield ('conflict', iz, zmatch, ia, amatch, ib,
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raise AssertionError(
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"can't handle a=b=base but unmatched")
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raise AssertionError("can't handle a=b=base but unmatched")
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# if the same part of the base was deleted on both sides
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# that's OK, we can just skip it.
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# assert ia == amatch
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# assert ib == bmatch
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# assert iz == zmatch
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yield 'unchanged', zmatch, zend
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def _refine_cherrypick_conflict(self, zstart, zend, astart, aend, bstart,
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"""When cherrypicking b => a, ignore matches with b and base."""
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# Do not emit regions which match, only regions which do not match
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matches = patiencediff.PatienceSequenceMatcher(
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None, self.base[zstart:zend], self.b[bstart:bend]
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).get_matching_blocks()
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for base_idx, b_idx, match_len in matches:
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conflict_b_len = b_idx - last_b_idx
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if conflict_b_len == 0:
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# There are no lines in b which conflict, so skip it
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zstart + last_base_idx, zstart + base_idx,
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aend, aend, bstart + last_b_idx, bstart + b_idx)
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# The first conflict gets the a-range
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yield ('conflict', zstart + last_base_idx, zstart +
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astart, aend, bstart + last_b_idx, bstart + b_idx)
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last_base_idx = base_idx + match_len
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last_b_idx = b_idx + match_len
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if last_base_idx != zend - zstart or last_b_idx != bend - bstart:
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yield ('conflict', zstart + last_base_idx, zstart + base_idx,
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aend, aend, bstart + last_b_idx, bstart + b_idx)
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# The first conflict gets the a-range
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yield ('conflict', zstart + last_base_idx, zstart + base_idx,
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astart, aend, bstart + last_b_idx, bstart + b_idx)
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yield ('conflict', zstart, zend, astart, aend, bstart, bend)
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def reprocess_merge_regions(self, merge_regions):
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"""Where there are conflict regions, remove the agreed lines.
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Lines where both A and B have made the same changes are
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for region in merge_regions:
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if region[0] != "conflict":
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type, iz, zmatch, ia, amatch, ib, bmatch = region
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a_region = self.a[ia:amatch]
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b_region = self.b[ib:bmatch]
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matches = patiencediff.PatienceSequenceMatcher(
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None, a_region, b_region).get_matching_blocks()
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matches = SequenceMatcher(None, a_region,
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b_region).get_matching_blocks()
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for region_ia, region_ib, region_len in matches[:-1]:
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if reg is not None:
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yield 'same', region_ia, region_len + region_ia
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yield 'same', region_ia, region_len+region_ia
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next_a = region_ia + region_len
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next_b = region_ib + region_len
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reg = self.mismatch_region(next_a, amatch, next_b, bmatch)
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if reg is not None:
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def mismatch_region(next_a, region_ia, next_b, region_ib):
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def mismatch_region(next_a, region_ia, next_b, region_ib):
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if next_a < region_ia or next_b < region_ib:
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return 'conflict', None, None, next_a, region_ia, next_b, region_ib
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def find_sync_regions(self):
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"""Return a list of sync regions, where both descendents match the base.
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amatches = patiencediff.PatienceSequenceMatcher(
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None, self.base, self.a).get_matching_blocks()
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bmatches = patiencediff.PatienceSequenceMatcher(
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None, self.base, self.b).get_matching_blocks()
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amatches = SequenceMatcher(None, self.base, self.a).get_matching_blocks()
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bmatches = SequenceMatcher(None, self.base, self.b).get_matching_blocks()
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len_a = len(amatches)
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len_b = len(bmatches)
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# there is an unconflicted block at i; how long does it
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# extend? until whichever one ends earlier.
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i = intersect((abase, abase + alen), (bbase, bbase + blen))
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i = intersect((abase, abase+alen), (bbase, bbase+blen))
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# found a match of base[i[0], i[1]]; this may be less than
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# the region that matches in either one
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# assert intlen <= alen
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# assert intlen <= blen
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# assert abase <= intbase
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# assert bbase <= intbase
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assert intlen <= alen
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assert intlen <= blen
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assert abase <= intbase
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assert bbase <= intbase
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asub = amatch + (intbase - abase)
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bsub = bmatch + (intbase - bbase)
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aend = asub + intlen
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bend = bsub + intlen
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# assert self.base[intbase:intend] == self.a[asub:aend], \
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# (self.base[intbase:intend], self.a[asub:aend])
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# assert self.base[intbase:intend] == self.b[bsub:bend]
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assert self.base[intbase:intend] == self.a[asub:aend], \
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(self.base[intbase:intend], self.a[asub:aend])
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assert self.base[intbase:intend] == self.b[bsub:bend]
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sl.append((intbase, intend,
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# advance whichever one ends first in the base text
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if (abase + alen) < (bbase + blen):
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intbase = len(self.base)
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abase = len(self.a)
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bbase = len(self.b)
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def find_unconflicted(self):
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"""Return a list of ranges in base that are not conflicted."""
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am = patiencediff.PatienceSequenceMatcher(
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None, self.base, self.a).get_matching_blocks()
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bm = patiencediff.PatienceSequenceMatcher(
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None, self.base, self.b).get_matching_blocks()
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# don't sync-up on lines containing only blanks or pounds
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junk_re = re.compile(r'^[ \t#]*$')
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am = SequenceMatcher(junk_re.match, self.base, self.a).get_matching_blocks()
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bm = SequenceMatcher(junk_re.match, self.base, self.b).get_matching_blocks()
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# as for diff3 and meld the syntax is "MINE BASE OTHER"
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with open(argv[1], 'rt') as f:
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with open(argv[2], 'rt') as f:
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with open(argv[3], 'rt') as f:
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a = file(argv[1], 'rt').readlines()
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base = file(argv[2], 'rt').readlines()
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b = file(argv[3], 'rt').readlines()
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m3 = Merge3(base, a, b)
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# for sr in m3.find_sync_regions():
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#for sr in m3.find_sync_regions():
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# sys.stdout.writelines(m3.merge_lines(name_a=argv[1], name_b=argv[3]))