Mercurial > hg > mercurial-crew-with-dirclash
view contrib/simplemerge @ 5192:33015dac5df5
convert: fix mercurial_sink.putcommit
Changeset 4ebc8693ce72 added some code to putcommit to avoid creating a
revision that touches no files, but this can break regular conversions
from some repositories:
- conceptually, since we're converting a repo, we should try to make
the new hg repo as similar as possible to the original repo - we
should create a new changeset, even if the original revision didn't
touch any files (maybe the commit message had some important bit);
- even if a "regular" revision that doesn't touch any file may seem
weird (and maybe even broken), it's completely legitimate for a merge
revision to not touch any file, and, if we just skip it, the
converted repo will end up with wrong history and possibly an extra
head.
As an example, say the crew and main hg repos are sync'ed. Somebody
sends an important patch to the mailing list. Matt quickly applies
and pushes it. But at the same time somebody also applies it to crew
and pushes it. Suppose the commit message ended up being a bit
different (say, there was a typo and somebody didn't fix it) or that
the date ended up being different (because of different patch-applying
scripts): the changeset hashes will be different, but the manifests
will be the same.
Since both changesets were pushed to public repos, it's hard to recall
them. If both are merged, the manifest from the resulting merge
revision will have the exact same contents as its parents - i.e. the
merge revision really doesn't touch any file at all.
To keep the file filtering stuff "working", the generic code was changed
to skip empty revisions if we're filtering the repo, fixing a bug in the
process (we want parents[0] instead of tip).
author | Alexis S. L. Carvalho <alexis@cecm.usp.br> |
---|---|
date | Fri, 17 Aug 2007 20:18:05 -0300 |
parents | ea7b982b6c08 |
children |
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#!/usr/bin/env python # Copyright (C) 2004, 2005 Canonical Ltd # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # mbp: "you know that thing where cvs gives you conflict markers?" # s: "i hate that." from mercurial import demandimport demandimport.enable() from mercurial import util, mdiff, fancyopts from mercurial.i18n import _ class CantReprocessAndShowBase(Exception): pass def warn(message): sys.stdout.flush() sys.stderr.write(message) sys.stderr.flush() def intersect(ra, rb): """Given two ranges return the range where they intersect or None. >>> intersect((0, 10), (0, 6)) (0, 6) >>> intersect((0, 10), (5, 15)) (5, 10) >>> intersect((0, 10), (10, 15)) >>> intersect((0, 9), (10, 15)) >>> intersect((0, 9), (7, 15)) (7, 9) """ assert ra[0] <= ra[1] assert rb[0] <= rb[1] sa = max(ra[0], rb[0]) sb = min(ra[1], rb[1]) if sa < sb: return sa, sb else: return None def compare_range(a, astart, aend, b, bstart, bend): """Compare a[astart:aend] == b[bstart:bend], without slicing. """ if (aend-astart) != (bend-bstart): return False for ia, ib in zip(xrange(astart, aend), xrange(bstart, bend)): if a[ia] != b[ib]: return False else: return True class Merge3Text(object): """3-way merge of texts. Given strings BASE, OTHER, THIS, tries to produce a combined text incorporating the changes from both BASE->OTHER and BASE->THIS.""" def __init__(self, basetext, atext, btext, base=None, a=None, b=None): self.basetext = basetext self.atext = atext self.btext = btext if base is None: base = mdiff.splitnewlines(basetext) if a is None: a = mdiff.splitnewlines(atext) if b is None: b = mdiff.splitnewlines(btext) self.base = base self.a = a self.b = b def merge_lines(self, name_a=None, name_b=None, name_base=None, start_marker='<<<<<<<', mid_marker='=======', end_marker='>>>>>>>', base_marker=None, reprocess=False): """Return merge in cvs-like form. """ self.conflicts = False newline = '\n' if len(self.a) > 0: if self.a[0].endswith('\r\n'): newline = '\r\n' elif self.a[0].endswith('\r'): newline = '\r' if base_marker and reprocess: raise CantReprocessAndShowBase() if name_a: start_marker = start_marker + ' ' + name_a if name_b: end_marker = end_marker + ' ' + name_b if name_base and base_marker: base_marker = base_marker + ' ' + name_base merge_regions = self.merge_regions() if reprocess is True: merge_regions = self.reprocess_merge_regions(merge_regions) for t in merge_regions: what = t[0] if what == 'unchanged': for i in range(t[1], t[2]): yield self.base[i] elif what == 'a' or what == 'same': for i in range(t[1], t[2]): yield self.a[i] elif what == 'b': for i in range(t[1], t[2]): yield self.b[i] elif what == 'conflict': self.conflicts = True yield start_marker + newline for i in range(t[3], t[4]): yield self.a[i] if base_marker is not None: yield base_marker + newline for i in range(t[1], t[2]): yield self.base[i] yield mid_marker + newline for i in range(t[5], t[6]): yield self.b[i] yield end_marker + newline else: raise ValueError(what) def merge_annotated(self): """Return merge with conflicts, showing origin of lines. Most useful for debugging merge. """ for t in self.merge_regions(): what = t[0] if what == 'unchanged': for i in range(t[1], t[2]): yield 'u | ' + self.base[i] elif what == 'a' or what == 'same': for i in range(t[1], t[2]): yield what[0] + ' | ' + self.a[i] elif what == 'b': for i in range(t[1], t[2]): yield 'b | ' + self.b[i] elif what == 'conflict': yield '<<<<\n' for i in range(t[3], t[4]): yield 'A | ' + self.a[i] yield '----\n' for i in range(t[5], t[6]): yield 'B | ' + self.b[i] yield '>>>>\n' else: raise ValueError(what) def merge_groups(self): """Yield sequence of line groups. Each one is a tuple: 'unchanged', lines Lines unchanged from base 'a', lines Lines taken from a 'same', lines Lines taken from a (and equal to b) 'b', lines Lines taken from b 'conflict', base_lines, a_lines, b_lines Lines from base were changed to either a or b and conflict. """ for t in self.merge_regions(): what = t[0] if what == 'unchanged': yield what, self.base[t[1]:t[2]] elif what == 'a' or what == 'same': yield what, self.a[t[1]:t[2]] elif what == 'b': yield what, self.b[t[1]:t[2]] elif what == 'conflict': yield (what, self.base[t[1]:t[2]], self.a[t[3]:t[4]], self.b[t[5]:t[6]]) else: raise ValueError(what) def merge_regions(self): """Return sequences of matching and conflicting regions. This returns tuples, where the first value says what kind we have: 'unchanged', start, end Take a region of base[start:end] 'same', astart, aend b and a are different from base but give the same result 'a', start, end Non-clashing insertion from a[start:end] Method is as follows: The two sequences align only on regions which match the base and both descendents. These are found by doing a two-way diff of each one against the base, and then finding the intersections between those regions. These "sync regions" are by definition unchanged in both and easily dealt with. The regions in between can be in any of three cases: conflicted, or changed on only one side. """ # section a[0:ia] has been disposed of, etc iz = ia = ib = 0 for zmatch, zend, amatch, aend, bmatch, bend in self.find_sync_regions(): #print 'match base [%d:%d]' % (zmatch, zend) matchlen = zend - zmatch assert matchlen >= 0 assert matchlen == (aend - amatch) assert matchlen == (bend - bmatch) len_a = amatch - ia len_b = bmatch - ib len_base = zmatch - iz assert len_a >= 0 assert len_b >= 0 assert len_base >= 0 #print 'unmatched a=%d, b=%d' % (len_a, len_b) if len_a or len_b: # try to avoid actually slicing the lists equal_a = compare_range(self.a, ia, amatch, self.base, iz, zmatch) equal_b = compare_range(self.b, ib, bmatch, self.base, iz, zmatch) same = compare_range(self.a, ia, amatch, self.b, ib, bmatch) if same: yield 'same', ia, amatch elif equal_a and not equal_b: yield 'b', ib, bmatch elif equal_b and not equal_a: yield 'a', ia, amatch elif not equal_a and not equal_b: yield 'conflict', iz, zmatch, ia, amatch, ib, bmatch else: raise AssertionError("can't handle a=b=base but unmatched") ia = amatch ib = bmatch iz = zmatch # if the same part of the base was deleted on both sides # that's OK, we can just skip it. if matchlen > 0: assert ia == amatch assert ib == bmatch assert iz == zmatch yield 'unchanged', zmatch, zend iz = zend ia = aend ib = bend def reprocess_merge_regions(self, merge_regions): """Where there are conflict regions, remove the agreed lines. Lines where both A and B have made the same changes are eliminated. """ for region in merge_regions: if region[0] != "conflict": yield region continue type, iz, zmatch, ia, amatch, ib, bmatch = region a_region = self.a[ia:amatch] b_region = self.b[ib:bmatch] matches = mdiff.get_matching_blocks(''.join(a_region), ''.join(b_region)) next_a = ia next_b = ib for region_ia, region_ib, region_len in matches[:-1]: region_ia += ia region_ib += ib reg = self.mismatch_region(next_a, region_ia, next_b, region_ib) if reg is not None: yield reg yield 'same', region_ia, region_len+region_ia next_a = region_ia + region_len next_b = region_ib + region_len reg = self.mismatch_region(next_a, amatch, next_b, bmatch) if reg is not None: yield reg def mismatch_region(next_a, region_ia, next_b, region_ib): if next_a < region_ia or next_b < region_ib: return 'conflict', None, None, next_a, region_ia, next_b, region_ib mismatch_region = staticmethod(mismatch_region) def find_sync_regions(self): """Return a list of sync regions, where both descendents match the base. Generates a list of (base1, base2, a1, a2, b1, b2). There is always a zero-length sync region at the end of all the files. """ ia = ib = 0 amatches = mdiff.get_matching_blocks(self.basetext, self.atext) bmatches = mdiff.get_matching_blocks(self.basetext, self.btext) len_a = len(amatches) len_b = len(bmatches) sl = [] while ia < len_a and ib < len_b: abase, amatch, alen = amatches[ia] bbase, bmatch, blen = bmatches[ib] # there is an unconflicted block at i; how long does it # extend? until whichever one ends earlier. i = intersect((abase, abase+alen), (bbase, bbase+blen)) if i: intbase = i[0] intend = i[1] intlen = intend - intbase # found a match of base[i[0], i[1]]; this may be less than # the region that matches in either one assert intlen <= alen assert intlen <= blen assert abase <= intbase assert bbase <= intbase asub = amatch + (intbase - abase) bsub = bmatch + (intbase - bbase) aend = asub + intlen bend = bsub + intlen assert self.base[intbase:intend] == self.a[asub:aend], \ (self.base[intbase:intend], self.a[asub:aend]) assert self.base[intbase:intend] == self.b[bsub:bend] sl.append((intbase, intend, asub, aend, bsub, bend)) # advance whichever one ends first in the base text if (abase + alen) < (bbase + blen): ia += 1 else: ib += 1 intbase = len(self.base) abase = len(self.a) bbase = len(self.b) sl.append((intbase, intbase, abase, abase, bbase, bbase)) return sl def find_unconflicted(self): """Return a list of ranges in base that are not conflicted.""" am = mdiff.get_matching_blocks(self.basetext, self.atext) bm = mdiff.get_matching_blocks(self.basetext, self.btext) unc = [] while am and bm: # there is an unconflicted block at i; how long does it # extend? until whichever one ends earlier. a1 = am[0][0] a2 = a1 + am[0][2] b1 = bm[0][0] b2 = b1 + bm[0][2] i = intersect((a1, a2), (b1, b2)) if i: unc.append(i) if a2 < b2: del am[0] else: del bm[0] return unc # bzr compatible interface, for the tests class Merge3(Merge3Text): """3-way merge of texts. Given BASE, OTHER, THIS, tries to produce a combined text incorporating the changes from both BASE->OTHER and BASE->THIS. All three will typically be sequences of lines.""" def __init__(self, base, a, b): basetext = '\n'.join([i.strip('\n') for i in base] + ['']) atext = '\n'.join([i.strip('\n') for i in a] + ['']) btext = '\n'.join([i.strip('\n') for i in b] + ['']) if util.binary(basetext) or util.binary(atext) or util.binary(btext): raise util.Abort(_("don't know how to merge binary files")) Merge3Text.__init__(self, basetext, atext, btext, base, a, b) def simplemerge(local, base, other, **opts): def readfile(filename): f = open(filename, "rb") text = f.read() f.close() if util.binary(text): msg = _("%s looks like a binary file.") % filename if not opts.get('text'): raise util.Abort(msg) elif not opts.get('quiet'): warn(_('warning: %s\n') % msg) return text name_a = local name_b = other labels = opts.get('label', []) if labels: name_a = labels.pop(0) if labels: name_b = labels.pop(0) if labels: raise util.Abort(_("can only specify two labels.")) localtext = readfile(local) basetext = readfile(base) othertext = readfile(other) orig = local local = os.path.realpath(local) if not opts.get('print'): opener = util.opener(os.path.dirname(local)) out = opener(os.path.basename(local), "w", atomictemp=True) else: out = sys.stdout reprocess = not opts.get('no_minimal') m3 = Merge3Text(basetext, localtext, othertext) for line in m3.merge_lines(name_a=name_a, name_b=name_b, reprocess=reprocess): out.write(line) if not opts.get('print'): out.rename() if m3.conflicts: if not opts.get('quiet'): warn(_("warning: conflicts during merge.\n")) return 1 options = [('L', 'label', [], _('labels to use on conflict markers')), ('a', 'text', None, _('treat all files as text')), ('p', 'print', None, _('print results instead of overwriting LOCAL')), ('', 'no-minimal', None, _('do not try to minimize conflict regions')), ('h', 'help', None, _('display help and exit')), ('q', 'quiet', None, _('suppress output'))] usage = _('''simplemerge [OPTS] LOCAL BASE OTHER Simple three-way file merge utility with a minimal feature set. Apply to LOCAL the changes necessary to go from BASE to OTHER. By default, LOCAL is overwritten with the results of this operation. ''') def showhelp(): sys.stdout.write(usage) sys.stdout.write('\noptions:\n') out_opts = [] for shortopt, longopt, default, desc in options: out_opts.append(('%2s%s' % (shortopt and '-%s' % shortopt, longopt and ' --%s' % longopt), '%s' % desc)) opts_len = max([len(opt[0]) for opt in out_opts]) for first, second in out_opts: sys.stdout.write(' %-*s %s\n' % (opts_len, first, second)) class ParseError(Exception): """Exception raised on errors in parsing the command line.""" def main(argv): try: opts = {} try: args = fancyopts.fancyopts(argv[1:], options, opts) except fancyopts.getopt.GetoptError, e: raise ParseError(e) if opts['help']: showhelp() return 0 if len(args) != 3: raise ParseError(_('wrong number of arguments')) return simplemerge(*args, **opts) except ParseError, e: sys.stdout.write("%s: %s\n" % (sys.argv[0], e)) showhelp() return 1 except util.Abort, e: sys.stderr.write("abort: %s\n" % e) return 255 except KeyboardInterrupt: return 255 if __name__ == '__main__': import sys import os sys.exit(main(sys.argv))