Mercurial > hg
view mercurial/config.py @ 34880:9e18ab7f7240
sparse-read: move from a recursive-based approach to a heap-based one
The previous recursive approach was trying to optimise each read slice to have
a good density. It had the tendency to over-optimize smaller slices while
leaving larger hole in others.
The new approach focuses on improving the combined density of all the reads,
instead of the individual slices. It slices at the largest gaps first, as they
reduce the total amount of read data the most efficiently.
Another benefit of this approach is that we iterate over the delta chain only
once, reducing the overhead of slicing long delta chains.
On the repository we use for tests, the new approach shows similar or faster
performance than the current default linear full read.
The repository contains about 450,000 revisions with many concurrent
topological branches. Tests have been run on two versions of the repository:
one built with the current delta constraint, and the other with an unlimited
delta span (using 'experimental.maxdeltachainspan=0')
Below are timings for building 1% of all the revision in the manifest log using
'hg perfrevlogrevisions -m'. Times are given in seconds. They include the new
couple of follow-up changeset in this series.
delta-span standard unlimited
linear-read 922s 632s
sparse-read 814s 566s
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Wed, 18 Oct 2017 12:53:00 +0200 |
parents | e5a2cfc524d4 |
children | 6d6bc544467a |
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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, pycompat, util, ) class config(object): def __init__(self, data=None, includepaths=None): self._data = {} self._unset = [] self._includepaths = includepaths or [] if data: for k in data._data: self._data[k] = data[k].copy() self._source = data._source.copy() else: self._source = util.cowdict() 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): self._source = self._source.preparewrite() for s, n in src._unset: ds = self._data.get(s, None) if ds is not None and n in ds: self._data[s] = ds.preparewrite() del self._data[s][n] del self._source[(s, n)] for s in src: ds = self._data.get(s, None) if ds: self._data[s] = ds.preparewrite() else: self._data[s] = util.cowsortdict() 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 list(self._data.get(section, {}).iteritems()) def set(self, section, item, value, source=""): if pycompat.ispy3: assert not isinstance(value, str), ( 'config values may not be unicode strings on Python 3') if section not in self: self._data[section] = util.cowsortdict() else: self._data[section] = self._data[section].preparewrite() self._data[section][item] = value if source: self._source = self._source.preparewrite() self._source[(section, item)] = source def restore(self, data): """restore data returned by self.backup""" self._source = self._source.preparewrite() if len(data) == 4: # restore old data section, item, value, source = data self._data[section] = self._data[section].preparewrite() 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 if remap: section = remap.get(section, section) 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.cowsortdict() 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: self._data[section] = self._data[section].preparewrite() 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, 'rb') assert getattr(fp, 'mode', r'rb') == r'rb', ( 'config files must be opened in binary mode, got fp=%r mode=%r' % ( fp, fp.mode)) self.parse(path, fp.read(), sections=sections, remap=remap, include=self.read) def parselist(value): """parse a configuration value as a list of comma/space separated strings >>> parselist(b'this,is "a small" ,test') ['this', 'is', 'a small', 'test'] """ def _parse_plain(parts, s, offset): whitespace = False while offset < len(s) and (s[offset:offset + 1].isspace() or s[offset:offset + 1] == ','): whitespace = True offset += 1 if offset >= len(s): return None, parts, offset if whitespace: parts.append('') if s[offset:offset + 1] == '"' and not parts[-1]: return _parse_quote, parts, offset + 1 elif s[offset:offset + 1] == '"' and parts[-1][-1] == '\\': parts[-1] = parts[-1][:-1] + s[offset:offset + 1] return _parse_plain, parts, offset + 1 parts[-1] += s[offset:offset + 1] return _parse_plain, parts, offset + 1 def _parse_quote(parts, s, offset): if offset < len(s) and s[offset:offset + 1] == '"': # "" parts.append('') offset += 1 while offset < len(s) and (s[offset:offset + 1].isspace() or s[offset:offset + 1] == ','): offset += 1 return _parse_plain, parts, offset while offset < len(s) and s[offset:offset + 1] != '"': if (s[offset:offset + 1] == '\\' and offset + 1 < len(s) and s[offset + 1:offset + 2] == '"'): offset += 1 parts[-1] += '"' else: parts[-1] += s[offset:offset + 1] offset += 1 if offset >= len(s): real_parts = _configlist(parts[-1]) if not real_parts: parts[-1] = '"' else: real_parts[0] = '"' + real_parts[0] parts = parts[:-1] parts.extend(real_parts) return None, parts, offset offset += 1 while offset < len(s) and s[offset:offset + 1] in [' ', ',']: offset += 1 if offset < len(s): if offset + 1 == len(s) and s[offset:offset + 1] == '"': parts[-1] += '"' offset += 1 else: parts.append('') else: return None, parts, offset return _parse_plain, parts, offset def _configlist(s): s = s.rstrip(' ,') if not s: return [] parser, parts, offset = _parse_plain, [''], 0 while parser: parser, parts, offset = parser(parts, s, offset) return parts if value is not None and isinstance(value, bytes): result = _configlist(value.lstrip(' ,\n')) else: result = value return result or []