Mercurial > hg-stable
view mercurial/mdiff.py @ 30777:7de7afd8bdd9
repair: begin implementation of in-place upgrading
Now that all the upgrade planning work is in place, we can start
doing the real work: actually upgrading a repository.
The main goal of this commit is to get the "framework" for running
in-place upgrade actions in place.
Rather than get too clever and low-level with regards to in-place
upgrades, our strategy is to create a new, temporary repository,
copy data to it, then replace the old data with the new. This allows
us to reuse a lot of code in localrepo.py around store interaction,
which will eventually consume the bulk of the upgrade code.
But we have to start small. This patch implements adding new
repository requirements. But it still sets up a temporary
repository and locks it and the source repo before performing the
requirements file swap. This means all the plumbing is in place
to implement store copying in subsequent commits.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 18 Dec 2016 16:59:04 -0800 |
parents | 3eeb8e138e5c |
children | d1901c4c8ec0 |
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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 __future__ import absolute_import import re import struct import zlib from .i18n import _ from . import ( base85, bdiff, error, mpatch, util, ) 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 nobinary ignores binary files noprefix disables the 'a/' and 'b/' prefixes (ignored in plain mode) 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, 'nobinary': False, 'noprefix': False, 'ignorews': False, 'ignorewsamount': False, 'ignoreblanklines': False, 'upgrade': False, } def __init__(self, **opts): for k in self.defaults.keys(): 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 error.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 = bdiff.fixws(text, 1) elif opts.ignorewsamount: text = bdiff.fixws(text, 0) if blank and opts.ignoreblanklines: text = re.sub('\n+', '\n', text).strip('\n') return text def splitblock(base1, lines1, base2, lines2, opts): # The input lines matches except for interwoven blank lines. We # transform it into a sequence of matching blocks and blank blocks. lines1 = [(wsclean(opts, l) and 1 or 0) for l in lines1] lines2 = [(wsclean(opts, l) and 1 or 0) for l in lines2] s1, e1 = 0, len(lines1) s2, e2 = 0, len(lines2) while s1 < e1 or s2 < e2: i1, i2, btype = s1, s2, '=' if (i1 >= e1 or lines1[i1] == 0 or i2 >= e2 or lines2[i2] == 0): # Consume the block of blank lines btype = '~' while i1 < e1 and lines1[i1] == 0: i1 += 1 while i2 < e2 and lines2[i2] == 0: i2 += 1 else: # Consume the matching lines while i1 < e1 and lines1[i1] == 1 and lines2[i2] == 1: i1 += 1 i2 += 1 yield [base1 + s1, base1 + i1, base2 + s2, base2 + i2], btype s1 = i1 s2 = i2 def blocksinrange(blocks, rangeb): """filter `blocks` like (a1, a2, b1, b2) from items outside line range `rangeb` from ``(b1, b2)`` point of view. Return `filteredblocks, rangea` where: * `filteredblocks` is list of ``block = (a1, a2, b1, b2), stype`` items of `blocks` that are inside `rangeb` from ``(b1, b2)`` point of view; a block ``(b1, b2)`` being inside `rangeb` if ``rangeb[0] < b2 and b1 < rangeb[1]``; * `rangea` is the line range w.r.t. to ``(a1, a2)`` parts of `blocks`. """ lbb, ubb = rangeb lba, uba = None, None filteredblocks = [] for block in blocks: (a1, a2, b1, b2), stype = block if lbb >= b1 and ubb <= b2 and stype == '=': # rangeb is within a single "=" hunk, restrict back linerange1 # by offsetting rangeb lba = lbb - b1 + a1 uba = ubb - b1 + a1 else: if b1 <= lbb < b2: if stype == '=': lba = a2 - (b2 - lbb) else: lba = a1 if b1 < ubb <= b2: if stype == '=': uba = a1 + (ubb - b1) else: uba = a2 if lbb < b2 and b1 < ubb: filteredblocks.append(block) if lba is None or uba is None or uba < lba: raise error.Abort(_('line range exceeds file size')) return filteredblocks, (lba, uba) def allblocks(text1, text2, opts=None, lines1=None, lines2=None): """Return (block, type) tuples, where block is an mdiff.blocks line entry. type is '=' for blocks matching exactly one another (bdiff blocks), '!' for non-matching blocks and '~' for blocks matching only after having filtered blank lines. line1 and line2 are text1 and text2 split with splitnewlines() if they are already available. """ if opts is None: opts = defaultopts if opts.ignorews or opts.ignorewsamount: text1 = wsclean(opts, text1, False) text2 = wsclean(opts, text2, False) diff = bdiff.blocks(text1, text2) 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] s = [s[1], s1[0], s[3], s1[2]] # bdiff sometimes gives huge matches past eof, this check eats them, # and deals with the special first match case described above if s[0] != s[1] or s[2] != s[3]: type = '!' if opts.ignoreblanklines: if lines1 is None: lines1 = splitnewlines(text1) if lines2 is None: lines2 = splitnewlines(text2) old = wsclean(opts, "".join(lines1[s[0]:s[1]])) new = wsclean(opts, "".join(lines2[s[2]:s[3]])) if old == new: type = '~' yield s, type yield s1, '=' def unidiff(a, ad, b, bd, fn1, fn2, opts=defaultopts): def datetag(date, fn=None): if not opts.git and not opts.nodates: return '\t%s\n' % date if fn and ' ' in fn: return '\t\n' return '\n' if not a and not b: return "" if opts.noprefix: aprefix = bprefix = '' else: aprefix = 'a/' bprefix = 'b/' epoch = util.datestr((0, 0)) fn1 = util.pconvert(fn1) fn2 = util.pconvert(fn2) 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) else: l1 = "--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1)) l2 = "+++ %s%s" % (bprefix + fn2, datetag(bd, fn2)) 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%s" % (aprefix, fn1, datetag(ad, fn1)) if b is None: l2 = '+++ /dev/null%s' % datetag(epoch) else: l2 = "+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2)) 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, "--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1))) l.insert(1, "+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2))) for ln in xrange(len(l)): if l[ln][-1] != '\n': l[ln] += "\n\ No newline at end of file\n" 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 lastfunc = [0, ''] 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: lastpos, func = lastfunc # walk backwards from the start of the context up to the start of # the previous hunk context until we find a line starting with an # alphanumeric char. for i in xrange(astart - 1, lastpos - 1, -1): if l1[i][0].isalnum(): func = ' ' + l1[i].rstrip()[:40] lastfunc[1] = func break # by recording this hunk's starting point as the next place to # start looking for function lines, we avoid reading any line in # the file more than once. lastfunc[0] = astart # zero-length hunk ranges report their start line as one less if alen: astart += 1 if blen: bstart += 1 yield "@@ -%d,%d +%d,%d @@%s\n" % (astart, alen, bstart, blen, func) for x in delta: yield x for x in xrange(a2, aend): yield ' ' + l1[x] # 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. # hunk = None ignoredlines = 0 for s, stype in allblocks(t1, t2, opts, l1, l2): a1, a2, b1, b2 = s if stype != '!': if stype == '~': # The diff context lines are based on t1 content. When # blank lines are ignored, the new lines offsets must # be adjusted as if equivalent blocks ('~') had the # same sizes on both sides. ignoredlines += (b2 - b1) - (a2 - a1) continue delta = [] old = l1[a1:a2] new = l2[b1:b2] b1 -= ignoredlines b2 -= ignoredlines 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 b85diff(to, tn): '''print base85-encoded binary diff''' def fmtline(line): l = len(line) if l <= 26: l = chr(ord('A') + l - 1) else: l = chr(l - 26 + ord('a') - 1) return '%c%s\n' % (l, base85.b85encode(line, True)) def chunk(text, csize=52): l = len(text) i = 0 while i < l: yield text[i:i + csize] i += csize if to is None: to = '' if tn is None: tn = '' if to == tn: return '' # TODO: deltas ret = [] ret.append('GIT binary patch\n') ret.append('literal %s\n' % len(tn)) for l in chunk(zlib.compress(tn)): ret.append(fmtline(l)) ret.append('\n') return ''.join(ret) 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 util.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) if length else '' def replacediffheader(oldlen, newlen): return struct.pack(">lll", 0, oldlen, newlen) patches = mpatch.patches patchedsize = mpatch.patchedsize textdiff = bdiff.bdiff