Mercurial > hg
view mercurial/config.py @ 25561:50a6c3c55db1 stable
parsers: do not cache RevlogError type (issue4451)
Index lookups raise RevlogError when the lookup fails. The previous
implementation was caching a reference to the RevlogError type in a
static variable. This assumed that the "mercurial.error" module was
only loaded once and there was only a single copy of it floating
around in memory. Unfortunately, in some situations - including
certain mod_wsgi configurations - this was not the case: the
"mercurial.error" module could be reloaded. It was possible for a
"RevlogError" reference from the first interpreter to be used by
a second interpreter. While the underlying thing was a
"mercurial.error.RevlogError," the object IDs were different, so
the Python code in revlog.py was failing to catch the exception! This
error has existed since the C index lookup code was implemented in
changeset e8d37b78acfb, which was first released in Mercurial 2.2 in
2012.
http://emptysqua.re/blog/python-c-extensions-and-mod-wsgi/#static-variables-are-shared
contains more details.
This patch removes the caching of the RevlogError type from the
function.
Since pretty much the entire function was refactored and the return
value of the function wasn't used, I changed the function signature
to not return anything.
For reasons unknown to me, we were calling PyErr_SetObject()
with the type of RevlogError and an instance of RevlogError. This
was equivalent to the Python code "raise RevlogError(RevlogError)".
This seemed wonky and completely unnecessary. The Python code only
cares about the type of the exception, not its contents. So I got
rid of this complexity.
This is my first Python C extension patch. Please give extra scrutiny
to it during review.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 12 Jun 2015 14:43:59 -0700 |
parents | fdfc9faca273 |
children | 3182965b3971 |
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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 i18n import _ import error, util import os, errno class config(object): def __init__(self, data=None): self._data = {} self._source = {} self._unset = [] 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 __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(r'\[([^\[]+)\]') itemre = util.re.compile(r'([^=\s][^=]*?)\s*=\s*(.*\S|)') contre = util.re.compile(r'\s+(\S|\S.*\S)\s*$') emptyre = util.re.compile(r'(;|#|\s*$)') commentre = util.re.compile(r'(;|#)') unsetre = util.re.compile(r'%unset\s+(\S+)') includere = util.re.compile(r'%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: inc = util.expandpath(m.group(1)) base = os.path.dirname(src) inc = os.path.normpath(os.path.join(base, inc)) if include: try: include(inc, remap=remap, sections=sections) except IOError, 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)