Mercurial > hg
view mercurial/manifest.py @ 24223:b4df0d0c49e7
manifest: move parsing functions up in file
These functions are about to change signature and be hidden inside the
manifestdict constructor. Doing the code motion now as an isolated
change to make things easier to review.
author | Augie Fackler <augie@google.com> |
---|---|
date | Sat, 07 Mar 2015 11:42:05 -0500 |
parents | feddc5284724 |
children | d71837d06597 |
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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 # Pure Python fallback def _parsemanifest(mfdict, fdict, lines): bin = revlog.bin for l in lines.splitlines(): f, n = l.split('\0') if len(n) > 40: fdict[f] = n[40:] mfdict[f] = bin(n[:40]) else: mfdict[f] = bin(n) def _parse(lines): mfdict = manifestdict() try: parsers.parse_manifest(mfdict, mfdict._flags, lines) except AttributeError: _parsemanifest(mfdict, mfdict._flags, lines) return mfdict class manifestdict(dict): def __init__(self): self._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 setflag(self, f, flags): """Set the flags (symlink, executable) for path f.""" self._flags[f] = flags def copy(self): copy = manifestdict() dict.__init__(copy, self) copy._flags = dict.copy(self._flags) return copy 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 filesnotin(self, m2): '''Set of files in this manifest that are not in the other''' files = set(self.iterkeys()) files.difference_update(m2.iterkeys()) return files def matches(self, match): '''generate a new manifest filtered by the match argument''' if match.always(): return self.copy() files = match.files() if (match.matchfn == match.exact or (not match.anypats() and util.all(fn in self for fn in files))): return self.intersectfiles(files) m = self.copy() for fn in m.keys(): if not match(fn): del m[fn] return m def diff(self, m2, clean=False): '''Finds changes between the current manifest and m2. Args: m2: the manifest to which this manifest should be compared. clean: if true, include files unchanged between these manifests with a None value in the returned dictionary. 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)) elif clean: diff[fn] = None 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 class manifest(revlog.revlog): def __init__(self, opener): # During normal operations, we expect to deal with not more than four # revs at a time (such as during commit --amend). When rebasing large # stacks of commits, the number can go up, hence the config knob below. cachesize = 4 opts = getattr(opener, 'options', None) if opts is not None: cachesize = opts.get('manifestcachesize', cachesize) self._mancache = util.lrucachedict(cachesize) 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) m = _parse(text) self._mancache[node] = (m, arraytext) return m 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: m = self._mancache[node][0] return m.get(f), m.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, m, 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 = m.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 = m.text() arraytext = array.array('c', text) cachedelta = None n = self.addrevision(text, transaction, link, p1, p2, cachedelta) self._mancache[n] = (m, arraytext) return n