Mercurial > hg
view mercurial/config.py @ 30446:b324b4e431e5
posix: give checkexec a fast path; keep the check files and test read only
Before, Mercurial would create a new temporary file every time, stat it, change
its exec mode, stat it again, and delete it. Most of this dance was done to
handle the rare and not-so-essential case of VFAT mounts on unix. The cost of
that was paid by the much more common and important case of using normal file
systems.
Instead, try to create and preserve .hg/cache/checkisexec and
.hg/cache/checknoexec with and without exec flag set. If the files exist and
have correct exec flags set, we can conclude that that file system supports the
exec flag. Best case, the whole exec check can thus be done with two stat
calls. Worst case, we delete the wrong files and check as usual. That will be
because temporary loss of exec bit or on file systems without support for the
exec bit. In that case we check as we did before, with the additional overhead
of one extra stat call.
It is possible that this different test algorithm in some cases on odd file
systems will give different behaviour. Again, I think it will be rare and
special cases and I think it is worth the risk.
test-clone.t happens to show the situation where checkisexec is left behind
from the old style check, while checknoexec only will be created next time a
exec check will be performed.
author | Mads Kiilerich <madski@unity3d.com> |
---|---|
date | Wed, 14 Jan 2015 01:15:26 +0100 |
parents | 954002426f78 |
children | fd3f4bf9325e |
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# config.py - configuration parsing for Mercurial # # Copyright 2009 Matt Mackall <mpm@selenic.com> and others # # 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 errno import os from .i18n import _ from . import ( error, util, ) class config(object): def __init__(self, data=None, includepaths=[]): self._data = {} self._source = {} self._unset = [] self._includepaths = includepaths if data: for k in data._data: self._data[k] = data[k].copy() self._source = data._source.copy() def copy(self): return config(self) def __contains__(self, section): return section in self._data def hasitem(self, section, item): return item in self._data.get(section, {}) def __getitem__(self, section): return self._data.get(section, {}) def __iter__(self): for d in self.sections(): yield d def update(self, src): for s, n in src._unset: if s in self and n in self._data[s]: del self._data[s][n] del self._source[(s, n)] for s in src: if s not in self: self._data[s] = util.sortdict() self._data[s].update(src._data[s]) self._source.update(src._source) def get(self, section, item, default=None): return self._data.get(section, {}).get(item, default) def backup(self, section, item): """return a tuple allowing restore to reinstall a previous value The main reason we need it is because it handles the "no data" case. """ try: value = self._data[section][item] source = self.source(section, item) return (section, item, value, source) except KeyError: return (section, item) def source(self, section, item): return self._source.get((section, item), "") def sections(self): return sorted(self._data.keys()) def items(self, section): return self._data.get(section, {}).items() def set(self, section, item, value, source=""): if section not in self: self._data[section] = util.sortdict() self._data[section][item] = value if source: self._source[(section, item)] = source def restore(self, data): """restore data returned by self.backup""" if len(data) == 4: # restore old data section, item, value, source = data self._data[section][item] = value self._source[(section, item)] = source else: # no data before, remove everything section, item = data if section in self._data: self._data[section].pop(item, None) self._source.pop((section, item), None) def parse(self, src, data, sections=None, remap=None, include=None): sectionre = util.re.compile(br'\[([^\[]+)\]') itemre = util.re.compile(br'([^=\s][^=]*?)\s*=\s*(.*\S|)') contre = util.re.compile(br'\s+(\S|\S.*\S)\s*$') emptyre = util.re.compile(br'(;|#|\s*$)') commentre = util.re.compile(br'(;|#)') unsetre = util.re.compile(br'%unset\s+(\S+)') includere = util.re.compile(br'%include\s+(\S|\S.*\S)\s*$') section = "" item = None line = 0 cont = False for l in data.splitlines(True): line += 1 if line == 1 and l.startswith('\xef\xbb\xbf'): # Someone set us up the BOM l = l[3:] if cont: if commentre.match(l): continue m = contre.match(l) if m: if sections and section not in sections: continue v = self.get(section, item) + "\n" + m.group(1) self.set(section, item, v, "%s:%d" % (src, line)) continue item = None cont = False m = includere.match(l) if m and include: expanded = util.expandpath(m.group(1)) includepaths = [os.path.dirname(src)] + self._includepaths for base in includepaths: inc = os.path.normpath(os.path.join(base, expanded)) try: include(inc, remap=remap, sections=sections) break except IOError as inst: if inst.errno != errno.ENOENT: raise error.ParseError(_("cannot include %s (%s)") % (inc, inst.strerror), "%s:%s" % (src, line)) continue if emptyre.match(l): continue m = sectionre.match(l) if m: section = m.group(1) if remap: section = remap.get(section, section) if section not in self: self._data[section] = util.sortdict() continue m = itemre.match(l) if m: item = m.group(1) cont = True if sections and section not in sections: continue self.set(section, item, m.group(2), "%s:%d" % (src, line)) continue m = unsetre.match(l) if m: name = m.group(1) if sections and section not in sections: continue if self.get(section, name) is not None: del self._data[section][name] self._unset.append((section, name)) continue raise error.ParseError(l.rstrip(), ("%s:%s" % (src, line))) def read(self, path, fp=None, sections=None, remap=None): if not fp: fp = util.posixfile(path) self.parse(path, fp.read(), sections, remap, self.read)