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view mercurial/mdiff.py @ 48687:f8f2ecdde4b5
branchmap: skip obsolete revisions while computing heads
It's time to make this part of core Mercurial obsolescence-aware.
Not considering obsolete revisions when computing heads is clearly what
Mercurial should do. But there are a couple of small issues:
- Let's say tip of the repo is obsolete. There are two ways of finding tiprev
for branchcache (both are in use): looking at input data for update() and
looking at computed heads after update(). Previously, repo tip would be
tiprev of the branchcache. With this patch, an obsolete revision can no
longer be tiprev. And depending on what way we use for finding tiprev (input
data vs computed heads) we'll get a different result. This is relevant when
recomputing cache key from cache contents, and may lead to updating cache for
obsolete revisions multiple times (not from scratch, because it still would
be considered valid for a subset of revisions in the repo).
- If all commits on a branch are obsolete, the branchcache will include that
branch, but the list of heads will be empty (that's why there's now `if not
heads` when recomputing tiprev/tipnode from cache contents). Having an entry
for every branch is currently required for notify extension (and
test-notify.t to pass), because notify doesn't handle revsets in its
subscription config very well and will throw an error if e.g. a branch
doesn't exist.
- Cloning static HTTP repos may try to stat() a non-existent obsstore file. The
issue is that we now care about obsolescence during clone, but statichttpvfs
doesn't implement a stat method, so a regular vfs.stat() is used, and it
assumes that file is local and calls os.stat(). During a clone, we're trying
to stat() .hg/store/obsstore, but in static HTTP case we provide a literal
URL to the obsstore file on the remote as if it were a local file path. On
windows it actually results in a failure in test-static-http.t.
The first issue is going to be addressed in a series dedicated to making sure
branchcache is properly and timely written on disk (it wasn't perfect even
before this patch, but there aren't enough tests to demonstrate that). The
second issue will be addressed in a future patch for notify extension that will
make it not raise an exception if a branch doesn't exist. And the third one was
partially addressed in the previous patch in this series and will be properly
fixed in a future patch when this series is accepted.
filteredhash() grows a keyword argument to make sure that branchcache is also
invalidated when there are new obsolete revisions in its repo view. This way
the on-disk cache format is unchanged and compatible between versions (although
it will obviously be recomputed when switching versions before/after this patch
and the repo has obsolete revisions).
There's one test that uses plain `hg up` without arguments while updated to a
pruned commit. To make this test pass, simply return current working directory
parent. Later in this series this code will be replaced by what prune command
does: updating to the closest non-obsolete ancestor.
Test changes:
test-branch-change.t: update branch head and cache update message. The head of
default listed in hg heads is changed because revision 2 was rewritten as 7,
and 1 is the closest ancestor on the same branch, so it's the head of default
now.
The cache invalidation message appears now because of the cache hash change,
since we're now accounting for obsolete revisions. Here's some context:
"served.hidden" repo filter means everything is visible (no filtered
revisions), so before this series branch2-served.hidden file would not contain
any cache hash, only revnum and node. Now it also has a hash when there are
obsolete changesets in the repo. The command that the message appears for is
changing branch of 5 and 6, which are now obsolete, so the cache hash changes.
In general, when cache is simply out-of-date, it can be updated using the old
version as a base. But if cache hash differs, then the cache for that
particular repo filter is recomputed (at least with the current
implementation). This is what happens here.
test-obsmarker-template.t: the pull reports 2 heads changed, but after that the
repo correctly sees only 1. The new message could be better, but it's still an
improvement over the previous one where hg pull suggested merging with an
obsolete revision.
test-obsolete.t: we can see these revisions in hg log --hidden, but they
shouldn't be considered heads even with --hidden.
test-rebase-obsolete{,2}.t: there were new heads created previously after
making new orphan changesets, but they weren't detected. Now we are properly
detecting and reporting them.
test-rebase-obsolete4.t: there's only one head now because the other head is
pruned and was falsely reported before.
test-static-http.t: add obsstore to the list of requested files. This file
doesn't exist on the remotes, but clients want it anyway (they get 404). This
is fine, because there are other nonexistent files that clients request, like
.hg/bookmarks or .hg/cache/tags2-served.
Differential Revision: https://phab.mercurial-scm.org/D12097
author | Anton Shestakov <av6@dwimlabs.net> |
---|---|
date | Fri, 07 Jan 2022 11:53:23 +0300 |
parents | 67064c238ae7 |
children | 6000f5b25c9b |
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# mdiff.py - diff and patch routines for mercurial # # Copyright 2005, 2006 Olivia Mackall <olivia@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 .pycompat import ( getattr, setattr, ) from . import ( diffhelper, encoding, error, policy, pycompat, util, ) from .utils import dateutil bdiff = policy.importmod('bdiff') mpatch = policy.importmod('mpatch') blocks = bdiff.blocks fixws = bdiff.fixws patches = mpatch.patches patchedsize = mpatch.patchedsize textdiff = bdiff.bdiff splitnewlines = bdiff.splitnewlines # TODO: this looks like it could be an attrs, which might help pytype 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 """ _HAS_DYNAMIC_ATTRIBUTES = True defaults = { b'context': 3, b'text': False, b'showfunc': False, b'git': False, b'nodates': False, b'nobinary': False, b'noprefix': False, b'index': 0, b'ignorews': False, b'ignorewsamount': False, b'ignorewseol': False, b'ignoreblanklines': False, b'upgrade': False, b'showsimilarity': False, b'worddiff': False, b'xdiff': False, } def __init__(self, **opts): opts = pycompat.byteskwargs(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.InputError( _(b'diff context lines count must be an integer, not %r') % pycompat.bytestr(self.context) ) def copy(self, **kwargs): opts = {k: getattr(self, k) for k in self.defaults} opts = pycompat.strkwargs(opts) 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(b'\n+', b'\n', text).strip(b'\n') if opts.ignorewseol: text = re.sub(br'[ \t\r\f]+\n', br'\n', text) 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, b'=' if i1 >= e1 or lines1[i1] == 0 or i2 >= e2 or lines2[i2] == 0: # Consume the block of blank lines btype = b'~' 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 hunkinrange(hunk, linerange): """Return True if `hunk` defined as (start, length) is in `linerange` defined as (lowerbound, upperbound). >>> hunkinrange((5, 10), (2, 7)) True >>> hunkinrange((5, 10), (6, 12)) True >>> hunkinrange((5, 10), (13, 17)) True >>> hunkinrange((5, 10), (3, 17)) True >>> hunkinrange((5, 10), (1, 3)) False >>> hunkinrange((5, 10), (18, 20)) False >>> hunkinrange((5, 10), (1, 5)) False >>> hunkinrange((5, 10), (15, 27)) False """ start, length = hunk lowerbound, upperbound = linerange return lowerbound < start + length and start < upperbound 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 == b'=': # 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 == b'=': lba = a2 - (b2 - lbb) else: lba = a1 if b1 < ubb <= b2: if stype == b'=': uba = a1 + (ubb - b1) else: uba = a2 if hunkinrange((b1, (b2 - b1)), rangeb): filteredblocks.append(block) if lba is None or uba is None or uba < lba: raise error.InputError(_(b'line range exceeds file size')) return filteredblocks, (lba, uba) def chooseblocksfunc(opts=None): if ( opts is None or not opts.xdiff or not util.safehasattr(bdiff, b'xdiffblocks') ): return bdiff.blocks else: return bdiff.xdiffblocks 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 or opts.ignorewseol: text1 = wsclean(opts, text1, False) text2 = wsclean(opts, text2, False) diff = chooseblocksfunc(opts)(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 = b'!' if opts.ignoreblanklines: if lines1 is None: lines1 = splitnewlines(text1) if lines2 is None: lines2 = splitnewlines(text2) old = wsclean(opts, b"".join(lines1[s[0] : s[1]])) new = wsclean(opts, b"".join(lines2[s[2] : s[3]])) if old == new: type = b'~' yield s, type yield s1, b'=' def unidiff(a, ad, b, bd, fn1, fn2, binary, opts=defaultopts): """Return a unified diff as a (headers, hunks) tuple. If the diff is not null, `headers` is a list with unified diff header lines "--- <original>" and "+++ <new>" and `hunks` is a generator yielding (hunkrange, hunklines) coming from _unidiff(). Otherwise, `headers` and `hunks` are empty. Set binary=True if either a or b should be taken as a binary file. """ def datetag(date, fn=None): if not opts.git and not opts.nodates: return b'\t%s' % date if fn and b' ' in fn: return b'\t' return b'' sentinel = [], () if not a and not b: return sentinel if opts.noprefix: aprefix = bprefix = b'' else: aprefix = b'a/' bprefix = b'b/' epoch = dateutil.datestr((0, 0)) fn1 = util.pconvert(fn1) fn2 = util.pconvert(fn2) if binary: if a and b and len(a) == len(b) and a == b: return sentinel headerlines = [] hunks = ((None, [b'Binary file %s has changed\n' % fn1]),) elif not a: without_newline = not b.endswith(b'\n') b = splitnewlines(b) if a is None: l1 = b'--- /dev/null%s' % datetag(epoch) else: l1 = b"--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1)) l2 = b"+++ %s%s" % (bprefix + fn2, datetag(bd, fn2)) headerlines = [l1, l2] size = len(b) hunkrange = (0, 0, 1, size) hunklines = [b"@@ -0,0 +1,%d @@\n" % size] + [b"+" + e for e in b] if without_newline: hunklines[-1] += b'\n' hunklines.append(diffhelper.MISSING_NEWLINE_MARKER) hunks = ((hunkrange, hunklines),) elif not b: without_newline = not a.endswith(b'\n') a = splitnewlines(a) l1 = b"--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1)) if b is None: l2 = b'+++ /dev/null%s' % datetag(epoch) else: l2 = b"+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2)) headerlines = [l1, l2] size = len(a) hunkrange = (1, size, 0, 0) hunklines = [b"@@ -1,%d +0,0 @@\n" % size] + [b"-" + e for e in a] if without_newline: hunklines[-1] += b'\n' hunklines.append(diffhelper.MISSING_NEWLINE_MARKER) hunks = ((hunkrange, hunklines),) else: hunks = _unidiff(a, b, opts=opts) if not next(hunks): return sentinel headerlines = [ b"--- %s%s%s" % (aprefix, fn1, datetag(ad, fn1)), b"+++ %s%s%s" % (bprefix, fn2, datetag(bd, fn2)), ] return headerlines, hunks def _unidiff(t1, t2, opts=defaultopts): """Yield hunks of a headerless unified diff from t1 and t2 texts. Each hunk consists of a (hunkrange, hunklines) tuple where `hunkrange` is a tuple (s1, l1, s2, l2) representing the range information of the hunk to form the '@@ -s1,l1 +s2,l2 @@' header and `hunklines` is a list of lines of the hunk combining said header followed by line additions and deletions. The hunks are prefixed with a bool. """ l1 = splitnewlines(t1) l2 = splitnewlines(t2) 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, b''] def yieldhunk(hunk): (astart, a2, bstart, b2, delta) = hunk aend = contextend(a2, len(l1)) alen = aend - astart blen = b2 - bstart + aend - a2 func = b"" 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 pycompat.xrange(astart - 1, lastpos - 1, -1): if l1[i][0:1].isalnum(): func = b' ' + l1[i].rstrip() # split long function name if ASCII. otherwise we have no # idea where the multi-byte boundary is, so just leave it. if encoding.isasciistr(func): func = func[:41] 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 hunkrange = astart, alen, bstart, blen hunklines = ( [b"@@ -%d,%d +%d,%d @@%s\n" % (hunkrange + (func,))] + delta + [b' ' + l1[x] for x in pycompat.xrange(a2, aend)] ) # If either file ends without a newline and the last line of # that file is part of a hunk, a marker is printed. If the # last line of both files is identical and neither ends in # a newline, print only one marker. That's the only case in # which the hunk can end in a shared line without a newline. skip = False if not t1.endswith(b'\n') and astart + alen == len(l1) + 1: for i in pycompat.xrange(len(hunklines) - 1, -1, -1): if hunklines[i].startswith((b'-', b' ')): if hunklines[i].startswith(b' '): skip = True hunklines[i] += b'\n' hunklines.insert(i + 1, diffhelper.MISSING_NEWLINE_MARKER) break if not skip and not t2.endswith(b'\n') and bstart + blen == len(l2) + 1: for i in pycompat.xrange(len(hunklines) - 1, -1, -1): if hunklines[i].startswith(b'+'): hunklines[i] += b'\n' hunklines.insert(i + 1, diffhelper.MISSING_NEWLINE_MARKER) break yield hunkrange, hunklines # 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 has_hunks = False for s, stype in allblocks(t1, t2, opts, l1, l2): a1, a2, b1, b2 = s if stype != b'!': if stype == b'~': # 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: if not has_hunks: has_hunks = True yield True 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) :] = [b' ' + x for x in l1[astart:a1]] delta[len(delta) :] = [b'-' + x for x in old] delta[len(delta) :] = [b'+' + x for x in new] if hunk: if not has_hunks: has_hunks = True yield True for x in yieldhunk(hunk): yield x elif not has_hunks: yield False def b85diff(to, tn): '''print base85-encoded binary diff''' def fmtline(line): l = len(line) if l <= 26: l = pycompat.bytechr(ord(b'A') + l - 1) else: l = pycompat.bytechr(l - 26 + ord(b'a') - 1) return b'%c%s\n' % (l, util.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 = b'' if tn is None: tn = b'' if to == tn: return b'' # TODO: deltas ret = [] ret.append(b'GIT binary patch\n') ret.append(b'literal %d\n' % len(tn)) for l in chunk(zlib.compress(tn)): ret.append(fmtline(l)) ret.append(b'\n') return b''.join(ret) def patchtext(bin): pos = 0 t = [] while pos < len(bin): p1, p2, l = struct.unpack(b">lll", bin[pos : pos + 12]) pos += 12 t.append(bin[pos : pos + l]) pos += l return b"".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(b">lll", 0, 0, length) if length else b'' def replacediffheader(oldlen, newlen): return struct.pack(b">lll", 0, oldlen, newlen)