Mercurial > hg
view mercurial/changelog.py @ 17013:c8eda7bbdcab
strip: incrementally update the branchheads cache after a strip
This function augments strip to incrementally update the branchheads cache
rather than recompute it from scratch. This speeds up the performance of strip
and rebase on repos with long history. The performance optimization only
happens if the revisions stripped are all on the same branch and the parents of
the stripped revisions are also on that same branch.
This adds a few test cases, particularly one that reproduces the extra heads
that mpm observed.
author | Joshua Redstone <joshua.redstone@fb.com> |
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date | Fri, 18 May 2012 12:45:47 -0700 |
parents | bc84a1aeaf5a |
children | 62c56c94c77e |
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# changelog.py - changelog 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 node import bin, hex, nullid from i18n import _ import util, error, revlog, encoding _defaultextra = {'branch': 'default'} def _string_escape(text): """ >>> d = {'nl': chr(10), 'bs': chr(92), 'cr': chr(13), 'nul': chr(0)} >>> s = "ab%(nl)scd%(bs)s%(bs)sn%(nul)sab%(cr)scd%(bs)s%(nl)s" % d >>> s 'ab\\ncd\\\\\\\\n\\x00ab\\rcd\\\\\\n' >>> res = _string_escape(s) >>> s == res.decode('string_escape') True """ # subset of the string_escape codec text = text.replace('\\', '\\\\').replace('\n', '\\n').replace('\r', '\\r') return text.replace('\0', '\\0') def decodeextra(text): """ >>> decodeextra(encodeextra({'foo': 'bar', 'baz': chr(0) + '2'})) {'foo': 'bar', 'baz': '\\x002', 'branch': 'default'} >>> decodeextra(encodeextra({'foo': 'bar', 'baz': chr(92) + chr(0) + '2'})) {'foo': 'bar', 'baz': '\\\\\\x002', 'branch': 'default'} """ extra = _defaultextra.copy() for l in text.split('\0'): if l: if '\\0' in l: # fix up \0 without getting into trouble with \\0 l = l.replace('\\\\', '\\\\\n') l = l.replace('\\0', '\0') l = l.replace('\n', '') k, v = l.decode('string_escape').split(':', 1) extra[k] = v return extra def encodeextra(d): # keys must be sorted to produce a deterministic changelog entry items = [_string_escape('%s:%s' % (k, d[k])) for k in sorted(d)] return "\0".join(items) class appender(object): '''the changelog index must be updated last on disk, so we use this class to delay writes to it''' def __init__(self, fp, buf): self.data = buf self.fp = fp self.offset = fp.tell() self.size = util.fstat(fp).st_size def end(self): return self.size + len("".join(self.data)) def tell(self): return self.offset def flush(self): pass def close(self): self.fp.close() def seek(self, offset, whence=0): '''virtual file offset spans real file and data''' if whence == 0: self.offset = offset elif whence == 1: self.offset += offset elif whence == 2: self.offset = self.end() + offset if self.offset < self.size: self.fp.seek(self.offset) def read(self, count=-1): '''only trick here is reads that span real file and data''' ret = "" if self.offset < self.size: s = self.fp.read(count) ret = s self.offset += len(s) if count > 0: count -= len(s) if count != 0: doff = self.offset - self.size self.data.insert(0, "".join(self.data)) del self.data[1:] s = self.data[0][doff:doff + count] self.offset += len(s) ret += s return ret def write(self, s): self.data.append(str(s)) self.offset += len(s) def delayopener(opener, target, divert, buf): def o(name, mode='r'): if name != target: return opener(name, mode) if divert: return opener(name + ".a", mode.replace('a', 'w')) # otherwise, divert to memory return appender(opener(name, mode), buf) return o class changelog(revlog.revlog): def __init__(self, opener): revlog.revlog.__init__(self, opener, "00changelog.i") if self._initempty: # changelogs don't benefit from generaldelta self.version &= ~revlog.REVLOGGENERALDELTA self._generaldelta = False self._realopener = opener self._delayed = False self._divert = False # hiddenrevs: revs that should be hidden by command and tools self.hiddenrevs = set() def delayupdate(self): "delay visibility of index updates to other readers" self._delayed = True self._divert = (len(self) == 0) self._delaybuf = [] self.opener = delayopener(self._realopener, self.indexfile, self._divert, self._delaybuf) def finalize(self, tr): "finalize index updates" self._delayed = False self.opener = self._realopener # move redirected index data back into place if self._divert: nfile = self.opener(self.indexfile + ".a") n = nfile.name nfile.close() util.rename(n, n[:-2]) elif self._delaybuf: fp = self.opener(self.indexfile, 'a') fp.write("".join(self._delaybuf)) fp.close() self._delaybuf = [] # split when we're done self.checkinlinesize(tr) def readpending(self, file): r = revlog.revlog(self.opener, file) self.index = r.index self.nodemap = r.nodemap self._nodecache = r._nodecache self._chunkcache = r._chunkcache def writepending(self): "create a file containing the unfinalized state for pretxnchangegroup" if self._delaybuf: # make a temporary copy of the index fp1 = self._realopener(self.indexfile) fp2 = self._realopener(self.indexfile + ".a", "w") fp2.write(fp1.read()) # add pending data fp2.write("".join(self._delaybuf)) fp2.close() # switch modes so finalize can simply rename self._delaybuf = [] self._divert = True if self._divert: return True return False def checkinlinesize(self, tr, fp=None): if not self._delayed: revlog.revlog.checkinlinesize(self, tr, fp) def read(self, node): """ format used: nodeid\n : manifest node in ascii user\n : user, no \n or \r allowed time tz extra\n : date (time is int or float, timezone is int) : extra is metadatas, encoded and separated by '\0' : older versions ignore it files\n\n : files modified by the cset, no \n or \r allowed (.*) : comment (free text, ideally utf-8) changelog v0 doesn't use extra """ text = self.revision(node) if not text: return (nullid, "", (0, 0), [], "", _defaultextra) last = text.index("\n\n") desc = encoding.tolocal(text[last + 2:]) l = text[:last].split('\n') manifest = bin(l[0]) user = encoding.tolocal(l[1]) tdata = l[2].split(' ', 2) if len(tdata) != 3: time = float(tdata[0]) try: # various tools did silly things with the time zone field. timezone = int(tdata[1]) except ValueError: timezone = 0 extra = _defaultextra else: time, timezone = float(tdata[0]), int(tdata[1]) extra = decodeextra(tdata[2]) files = l[3:] return (manifest, user, (time, timezone), files, desc, extra) def add(self, manifest, files, desc, transaction, p1, p2, user, date=None, extra=None): # Convert to UTF-8 encoded bytestrings as the very first # thing: calling any method on a localstr object will turn it # into a str object and the cached UTF-8 string is thus lost. user, desc = encoding.fromlocal(user), encoding.fromlocal(desc) user = user.strip() # An empty username or a username with a "\n" will make the # revision text contain two "\n\n" sequences -> corrupt # repository since read cannot unpack the revision. if not user: raise error.RevlogError(_("empty username")) if "\n" in user: raise error.RevlogError(_("username %s contains a newline") % repr(user)) # strip trailing whitespace and leading and trailing empty lines desc = '\n'.join([l.rstrip() for l in desc.splitlines()]).strip('\n') if date: parseddate = "%d %d" % util.parsedate(date) else: parseddate = "%d %d" % util.makedate() if extra: branch = extra.get("branch") if branch in ("default", ""): del extra["branch"] elif branch in (".", "null", "tip"): raise error.RevlogError(_('the name \'%s\' is reserved') % branch) if extra: extra = encodeextra(extra) parseddate = "%s %s" % (parseddate, extra) l = [hex(manifest), user, parseddate] + sorted(files) + ["", desc] text = "\n".join(l) return self.addrevision(text, transaction, len(self), p1, p2)