Mercurial > hg
view mercurial/manifest.py @ 21990:48e32c2c499b stable
context: call normal on the right object
dirstate.normal is the method that marks files as unchanged/normal.
Rev 20a30cd41d21 started caching dirstate.normal in order to improve
performance. However, there was an error in the patch: taking the wlock, under
some conditions depending on platform, can cause a new dirstate object to be
created. Caching dirstate.normal before calling wlock would then cause the
fixup calls below to be on the old dirstate object, effectively disappearing
into the ether.
On Unix and Unix-like OSes, the condition under which we create a new dirstate
object is 'the dirstate file has been modified since the last time we opened
it'. This happens pretty rarely, so the object is usually the same -- there's
little impact.
On Windows, the condition is 'always'. This means files in the lookup state are
never marked normal, so the bug has a serious performance impact since all the
files in the lookup state are re-read every time hg status is run.
author | Siddharth Agarwal <sid0@fb.com> |
---|---|
date | Fri, 01 Aug 2014 18:30:18 -0700 |
parents | 090dcaaf3fff |
children | dc97e04c12ad |
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# manifest.py - manifest revision class for mercurial # # Copyright 2005-2007 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 mdiff, parsers, error, revlog, util, dicthelpers import array, struct class manifestdict(dict): def __init__(self, mapping=None, flags=None): if mapping is None: mapping = {} if flags is None: flags = {} dict.__init__(self, mapping) self._flags = flags def flags(self, f): return self._flags.get(f, "") def withflags(self): return set(self._flags.keys()) def set(self, f, flags): self._flags[f] = flags def copy(self): return manifestdict(self, dict.copy(self._flags)) def intersectfiles(self, files): '''make a new manifestdict with the intersection of self with files The algorithm assumes that files is much smaller than self.''' ret = manifestdict() for fn in files: if fn in self: ret[fn] = self[fn] flags = self._flags.get(fn, None) if flags: ret._flags[fn] = flags return ret def flagsdiff(self, d2): return dicthelpers.diff(self._flags, d2._flags, "") class manifest(revlog.revlog): def __init__(self, opener): # we expect to deal with not more than four revs at a time, # during a commit --amend self._mancache = util.lrucachedict(4) revlog.revlog.__init__(self, opener, "00manifest.i") def parse(self, lines): mfdict = manifestdict() parsers.parse_manifest(mfdict, mfdict._flags, lines) return mfdict def readdelta(self, node): r = self.rev(node) return self.parse(mdiff.patchtext(self.revdiff(self.deltaparent(r), r))) def readfast(self, node): '''use the faster of readdelta or read''' r = self.rev(node) deltaparent = self.deltaparent(r) if deltaparent != revlog.nullrev and deltaparent in self.parentrevs(r): return self.readdelta(node) return self.read(node) def read(self, node): if node == revlog.nullid: return manifestdict() # don't upset local cache if node in self._mancache: return self._mancache[node][0] text = self.revision(node) arraytext = array.array('c', text) mapping = self.parse(text) self._mancache[node] = (mapping, arraytext) return mapping def _search(self, m, s, lo=0, hi=None): '''return a tuple (start, end) that says where to find s within m. If the string is found m[start:end] are the line containing that string. If start == end the string was not found and they indicate the proper sorted insertion point. m should be a buffer or a string s is a string''' def advance(i, c): while i < lenm and m[i] != c: i += 1 return i if not s: return (lo, lo) lenm = len(m) if not hi: hi = lenm while lo < hi: mid = (lo + hi) // 2 start = mid while start > 0 and m[start - 1] != '\n': start -= 1 end = advance(start, '\0') if m[start:end] < s: # we know that after the null there are 40 bytes of sha1 # this translates to the bisect lo = mid + 1 lo = advance(end + 40, '\n') + 1 else: # this translates to the bisect hi = mid hi = start end = advance(lo, '\0') found = m[lo:end] if s == found: # we know that after the null there are 40 bytes of sha1 end = advance(end + 40, '\n') return (lo, end + 1) else: return (lo, lo) def find(self, node, f): '''look up entry for a single file efficiently. return (node, flags) pair if found, (None, None) if not.''' if node in self._mancache: mapping = self._mancache[node][0] return mapping.get(f), mapping.flags(f) text = self.revision(node) start, end = self._search(text, f) if start == end: return None, None l = text[start:end] f, n = l.split('\0') return revlog.bin(n[:40]), n[40:-1] def add(self, map, transaction, link, p1=None, p2=None, changed=None): # apply the changes collected during the bisect loop to our addlist # return a delta suitable for addrevision def addlistdelta(addlist, x): # for large addlist arrays, building a new array is cheaper # than repeatedly modifying the existing one currentposition = 0 newaddlist = array.array('c') for start, end, content in x: newaddlist += addlist[currentposition:start] if content: newaddlist += array.array('c', content) currentposition = end newaddlist += addlist[currentposition:] deltatext = "".join(struct.pack(">lll", start, end, len(content)) + content for start, end, content in x) return deltatext, newaddlist def checkforbidden(l): for f in l: if '\n' in f or '\r' in f: raise error.RevlogError( _("'\\n' and '\\r' disallowed in filenames: %r") % f) # if we're using the cache, make sure it is valid and # parented by the same node we're diffing against if not (changed and p1 and (p1 in self._mancache)): files = sorted(map) checkforbidden(files) # if this is changed to support newlines in filenames, # be sure to check the templates/ dir again (especially *-raw.tmpl) hex, flags = revlog.hex, map.flags text = ''.join("%s\0%s%s\n" % (f, hex(map[f]), flags(f)) for f in files) arraytext = array.array('c', text) cachedelta = None else: added, removed = changed addlist = self._mancache[p1][1] checkforbidden(added) # combine the changed lists into one list for sorting work = [(x, False) for x in added] work.extend((x, True) for x in removed) # this could use heapq.merge() (from Python 2.6+) or equivalent # since the lists are already sorted work.sort() delta = [] dstart = None dend = None dline = [""] start = 0 # zero copy representation of addlist as a buffer addbuf = util.buffer(addlist) # start with a readonly loop that finds the offset of # each line and creates the deltas for f, todelete in work: # bs will either be the index of the item or the insert point start, end = self._search(addbuf, f, start) if not todelete: l = "%s\0%s%s\n" % (f, revlog.hex(map[f]), map.flags(f)) else: if start == end: # item we want to delete was not found, error out raise AssertionError( _("failed to remove %s from manifest") % f) l = "" if dstart is not None and dstart <= start and dend >= start: if dend < end: dend = end if l: dline.append(l) else: if dstart is not None: delta.append([dstart, dend, "".join(dline)]) dstart = start dend = end dline = [l] if dstart is not None: delta.append([dstart, dend, "".join(dline)]) # apply the delta to the addlist, and get a delta for addrevision deltatext, addlist = addlistdelta(addlist, delta) cachedelta = (self.rev(p1), deltatext) arraytext = addlist text = util.buffer(arraytext) n = self.addrevision(text, transaction, link, p1, p2, cachedelta) self._mancache[n] = (map, arraytext) return n