Mercurial > hg
view mercurial/mdiff.py @ 14451:c78d41db6f88
patch: refactor file creation/removal detection
The patcher has to know if a file is being created or removed to check if the
target already exists, or to actually unlink the file when a hunk emptying it
is applied. This was done by embedding the creation/removal information in the
first (and only) hunk attached to the file.
There are two problems with this approach:
- creation/removal is really a property of the file being patched and not its
hunk.
- for regular patches, file creation cannot be deduced at parsing time: there
are case where the *stripped* file paths must be compared. Modifying hunks
after their creation is clumsy and prevent further refactorings related to
copies handling.
Instead, we delegate this job to selectfile() which has all the relevant
information, and remove the hunk createfile() and rmfile() methods.
author | Patrick Mezard <pmezard@gmail.com> |
---|---|
date | Fri, 27 May 2011 21:50:09 +0200 |
parents | 8eb758ea738c |
children | 16dc9a32ca04 |
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# mdiff.py - diff and patch routines for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from i18n import _ import bdiff, mpatch, util import re, struct def splitnewlines(text): '''like str.splitlines, but only split on newlines.''' lines = [l + '\n' for l in text.split('\n')] if lines: if lines[-1] == '\n': lines.pop() else: lines[-1] = lines[-1][:-1] return lines class diffopts(object): '''context is the number of context lines text treats all files as text showfunc enables diff -p output git enables the git extended patch format nodates removes dates from diff headers ignorews ignores all whitespace changes in the diff ignorewsamount ignores changes in the amount of whitespace ignoreblanklines ignores changes whose lines are all blank upgrade generates git diffs to avoid data loss ''' defaults = { 'context': 3, 'text': False, 'showfunc': False, 'git': False, 'nodates': False, 'ignorews': False, 'ignorewsamount': False, 'ignoreblanklines': False, 'upgrade': False, } __slots__ = defaults.keys() def __init__(self, **opts): for k in self.__slots__: v = opts.get(k) if v is None: v = self.defaults[k] setattr(self, k, v) try: self.context = int(self.context) except ValueError: raise util.Abort(_('diff context lines count must be ' 'an integer, not %r') % self.context) def copy(self, **kwargs): opts = dict((k, getattr(self, k)) for k in self.defaults) opts.update(kwargs) return diffopts(**opts) defaultopts = diffopts() def wsclean(opts, text, blank=True): if opts.ignorews: text = re.sub('[ \t\r]+', '', text) elif opts.ignorewsamount: text = re.sub('[ \t\r]+', ' ', text) text = text.replace(' \n', '\n') if blank and opts.ignoreblanklines: text = re.sub('\n+', '', text) return text def diffline(revs, a, b, opts): parts = ['diff'] if opts.git: parts.append('--git') if revs and not opts.git: parts.append(' '.join(["-r %s" % rev for rev in revs])) if opts.git: parts.append('a/%s' % a) parts.append('b/%s' % b) else: parts.append(a) return ' '.join(parts) + '\n' def unidiff(a, ad, b, bd, fn1, fn2, r=None, opts=defaultopts): def datetag(date, addtab=True): if not opts.git and not opts.nodates: return '\t%s\n' % date if addtab and ' ' in fn1: return '\t\n' return '\n' if not a and not b: return "" epoch = util.datestr((0, 0)) if not opts.text and (util.binary(a) or util.binary(b)): if a and b and len(a) == len(b) and a == b: return "" l = ['Binary file %s has changed\n' % fn1] elif not a: b = splitnewlines(b) if a is None: l1 = '--- /dev/null%s' % datetag(epoch, False) else: l1 = "--- %s%s" % ("a/" + fn1, datetag(ad)) l2 = "+++ %s%s" % ("b/" + fn2, datetag(bd)) l3 = "@@ -0,0 +1,%d @@\n" % len(b) l = [l1, l2, l3] + ["+" + e for e in b] elif not b: a = splitnewlines(a) l1 = "--- %s%s" % ("a/" + fn1, datetag(ad)) if b is None: l2 = '+++ /dev/null%s' % datetag(epoch, False) else: l2 = "+++ %s%s" % ("b/" + fn2, datetag(bd)) l3 = "@@ -1,%d +0,0 @@\n" % len(a) l = [l1, l2, l3] + ["-" + e for e in a] else: al = splitnewlines(a) bl = splitnewlines(b) l = list(_unidiff(a, b, al, bl, opts=opts)) if not l: return "" l.insert(0, "--- a/%s%s" % (fn1, datetag(ad))) l.insert(1, "+++ b/%s%s" % (fn2, datetag(bd))) for ln in xrange(len(l)): if l[ln][-1] != '\n': l[ln] += "\n\ No newline at end of file\n" if r: l.insert(0, diffline(r, fn1, fn2, opts)) return "".join(l) # creates a headerless unified diff # t1 and t2 are the text to be diffed # l1 and l2 are the text broken up into lines def _unidiff(t1, t2, l1, l2, opts=defaultopts): def contextend(l, len): ret = l + opts.context if ret > len: ret = len return ret def contextstart(l): ret = l - opts.context if ret < 0: return 0 return ret def yieldhunk(hunk): (astart, a2, bstart, b2, delta) = hunk aend = contextend(a2, len(l1)) alen = aend - astart blen = b2 - bstart + aend - a2 func = "" if opts.showfunc: # walk backwards from the start of the context # to find a line starting with an alphanumeric char. for x in xrange(astart - 1, -1, -1): t = l1[x].rstrip() if funcre.match(t): func = ' ' + t[:40] break yield "@@ -%d,%d +%d,%d @@%s\n" % (astart + 1, alen, bstart + 1, blen, func) for x in delta: yield x for x in xrange(a2, aend): yield ' ' + l1[x] if opts.showfunc: funcre = re.compile('\w') # bdiff.blocks gives us the matching sequences in the files. The loop # below finds the spaces between those matching sequences and translates # them into diff output. # if opts.ignorews or opts.ignorewsamount: t1 = wsclean(opts, t1, False) t2 = wsclean(opts, t2, False) diff = bdiff.blocks(t1, t2) hunk = None for i, s1 in enumerate(diff): # The first match is special. # we've either found a match starting at line 0 or a match later # in the file. If it starts later, old and new below will both be # empty and we'll continue to the next match. if i > 0: s = diff[i - 1] else: s = [0, 0, 0, 0] delta = [] a1 = s[1] a2 = s1[0] b1 = s[3] b2 = s1[2] old = l1[a1:a2] new = l2[b1:b2] # bdiff sometimes gives huge matches past eof, this check eats them, # and deals with the special first match case described above if not old and not new: continue if opts.ignoreblanklines: if wsclean(opts, "".join(old)) == wsclean(opts, "".join(new)): continue astart = contextstart(a1) bstart = contextstart(b1) prev = None if hunk: # join with the previous hunk if it falls inside the context if astart < hunk[1] + opts.context + 1: prev = hunk astart = hunk[1] bstart = hunk[3] else: for x in yieldhunk(hunk): yield x if prev: # we've joined the previous hunk, record the new ending points. hunk[1] = a2 hunk[3] = b2 delta = hunk[4] else: # create a new hunk hunk = [astart, a2, bstart, b2, delta] delta[len(delta):] = [' ' + x for x in l1[astart:a1]] delta[len(delta):] = ['-' + x for x in old] delta[len(delta):] = ['+' + x for x in new] if hunk: for x in yieldhunk(hunk): yield x def patchtext(bin): pos = 0 t = [] while pos < len(bin): p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12]) pos += 12 t.append(bin[pos:pos + l]) pos += l return "".join(t) def patch(a, bin): if len(a) == 0: # skip over trivial delta header return buffer(bin, 12) return mpatch.patches(a, [bin]) # similar to difflib.SequenceMatcher.get_matching_blocks def get_matching_blocks(a, b): return [(d[0], d[2], d[1] - d[0]) for d in bdiff.blocks(a, b)] def trivialdiffheader(length): return struct.pack(">lll", 0, 0, length) patches = mpatch.patches patchedsize = mpatch.patchedsize textdiff = bdiff.bdiff