Mercurial > hg
view mercurial/config.py @ 39559:07b58266bce3
wireprotov2: implement commands as a generator of objects
Previously, wire protocol version 2 inherited version 1's model of
having separate types to represent the results of different wire
protocol commands.
As I implemented more powerful commands in future commits, I found
I was using a common pattern of returning a special type to hold a
generator. This meant the command function required a closure to
do most of the work. That made logic flow more difficult to follow.
I also noticed that many commands were effectively a sequence of
objects to be CBOR encoded.
I think it makes sense to define version 2 commands as generators.
This way, commands can simply emit the data structures they wish to
send to the client. This eliminates the need for a closure in
command functions and removes encoding from the bodies of commands.
As part of this commit, the handling of response objects has been
moved into the serverreactor class. This puts the reactor in the
driver's seat with regards to CBOR encoding and error handling.
Having error handling in the function that emits frames is
particularly important because exceptions in that function can lead
to things getting in a bad state: I'm fairly certain that uncaught
exceptions in the frame generator were causing deadlocks.
I also introduced a dedicated error type for explicit error reporting
in command handlers. This will be used in subsequent commits.
There's still a bit of work to be done here, especially around
formalizing the error handling "protocol." I've added yet another
TODO to track this so we don't forget.
Test output changed because we're using generators and no longer know
we are at the end of the data until we hit the end of the generator.
This means we can't emit the end-of-stream flag until we've exhausted
the generator. Hence the introduction of 0-sized end-of-stream frames.
Differential Revision: https://phab.mercurial-scm.org/D4472
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 05 Sep 2018 09:06:40 -0700 |
parents | 48378d0e9479 |
children | 4ad002b2584d |
line wrap: on
line source
# 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:%d" % (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:%d" % (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 []