Mercurial > hg
view mercurial/manifest.py @ 23724:aafeaba22826 stable
revset: drop pre-lazyset optimization for stringset of subset == entire repo
It was introduced at e44ebd2a142a, where spanset.__contains__() did not exist.
Nowadays, we have to pay huge penalty for len(subset).
The following example showed that OR operation could be O(n * m^2)
(n: len(repo), m: number of OR operators, m >= 2) probably because of
filteredset.__len__.
revset #0: 0|1|2|3|4|5|6|7|8|9
0) wall 8.092713 comb 8.090000 user 8.090000 sys 0.000000 (best of 3)
1) wall 0.445354 comb 0.450000 user 0.430000 sys 0.020000 (best of 22)
2) wall 0.000389 comb 0.000000 user 0.000000 sys 0.000000 (best of 7347)
(0: 3.2.4, 1: 3.1.2, 2: this patch)
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Sat, 03 Jan 2015 10:25:08 +0900 |
parents | 6f53629ad273 |
children | a4679a74df14 |
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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 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 __setitem__(self, k, v): assert v is not None dict.__setitem__(self, k, v) def flags(self, f): return self._flags.get(f, "") def withflags(self): return set(self._flags.keys()) def setflag(self, f, flags): """Set the flags (symlink, executable) for path f.""" 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 diff(self, m2): '''Finds changes between the current manifest and m2. The result is returned as a dict with filename as key and values of the form ((n1,fl1),(n2,fl2)), where n1/n2 is the nodeid in the current/other manifest and fl1/fl2 is the flag in the current/other manifest. Where the file does not exist, the nodeid will be None and the flags will be the empty string.''' diff = {} for fn, n1 in self.iteritems(): fl1 = self._flags.get(fn, '') n2 = m2.get(fn, None) fl2 = m2._flags.get(fn, '') if n2 is None: fl2 = '' if n1 != n2 or fl1 != fl2: diff[fn] = ((n1, fl1), (n2, fl2)) for fn, n2 in m2.iteritems(): if fn not in self: fl2 = m2._flags.get(fn, '') diff[fn] = ((None, ''), (n2, fl2)) return diff def text(self): """Get the full data of this manifest as a bytestring.""" fl = sorted(self) _checkforbidden(fl) hex, flags = revlog.hex, self.flags # if this is changed to support newlines in filenames, # be sure to check the templates/ dir again (especially *-raw.tmpl) return ''.join("%s\0%s%s\n" % (f, hex(self[f]), flags(f)) for f in fl) def fastdelta(self, base, changes): """Given a base manifest text as an array.array and a list of changes relative to that text, compute a delta that can be used by revlog. """ delta = [] dstart = None dend = None dline = [""] start = 0 # zero copy representation of base as a buffer addbuf = util.buffer(base) # start with a readonly loop that finds the offset of # each line and creates the deltas for f, todelete in changes: # bs will either be the index of the item or the insert point start, end = _msearch(addbuf, f, start) if not todelete: l = "%s\0%s%s\n" % (f, revlog.hex(self[f]), self.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 base, and get a delta for addrevision deltatext, arraytext = _addlistdelta(base, delta) return arraytext, deltatext def _msearch(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 _checkforbidden(l): """Check filenames for illegal characters.""" for f in l: if '\n' in f or '\r' in f: raise error.RevlogError( _("'\\n' and '\\r' disallowed in filenames: %r") % f) # 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 _parse(lines): mfdict = manifestdict() parsers.parse_manifest(mfdict, mfdict._flags, lines) return mfdict 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 readdelta(self, node): r = self.rev(node) return _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 = _parse(text) self._mancache[node] = (mapping, arraytext) return mapping 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 = _msearch(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, p2, added, removed): if p1 in self._mancache: # If our first parent is in the manifest cache, we can # compute a delta here using properties we know about the # manifest up-front, which may save time later for the # revlog layer. _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() arraytext, deltatext = map.fastdelta(self._mancache[p1][1], work) cachedelta = self.rev(p1), deltatext text = util.buffer(arraytext) else: # The first parent manifest isn't already loaded, so we'll # just encode a fulltext of the manifest and pass that # through to the revlog layer, and let it handle the delta # process. text = map.text() arraytext = array.array('c', text) cachedelta = None n = self.addrevision(text, transaction, link, p1, p2, cachedelta) self._mancache[n] = (map, arraytext) return n