view mercurial/config.py @ 25732:b94df10cc3b5

hghave: allow adding customized features at runtime

Before this patch, there is no way to add customized features to
`hghave` without changing `hghave` and `hghave.py` themselves.

This decreases reusability of `run-tests.py` framework for third party
tools, because they may want to examine custom features at runtime
(e.g.  existence of some external tools).

To allow adding customized features at runtime, this patch makes
`hghave` import `hghaveaddon` module, only when `hghaveaddon.py` file
can be found in directories below:

  - `TESTDIR` for invocation via `run-tests.py`
  - `.` for invocation via command line

The path to the directory where `hghaveaddon.py` should be placed is
added to `sys.path` only while importing `hghaveaddon`, because:

  - `.` may not be added to `PYTHONPATH`

  - adding additional path to `sys.path` may change behavior of
    subsequent `import` for other features

`hghave` is terminated with exit code '2' at failure of `import
hghaveaddon`, because exit code '2' terminates `run-tests.py`
immediately.

This is a one of preparations for issue4677.

# config.py - configuration parsing for Mercurial
#
#  Copyright 2009 Matt Mackall <[e-mail]> 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, 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 __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 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)