configparse.py

# The contents of this file are subject to the Common Public Attribution
# License Version 1.0. (the "License"); you may not use this file except in
# compliance with the License. You may obtain a copy of the License at
# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
# License Version 1.1, but Sections 14 and 15 have been added to cover use of
# software over a computer network and provide for limited attribution for the
# Original Developer. In addition, Exhibit A has been modified to be consistent
# with Exhibit B.
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
# the specific language governing rights and limitations under the License.
#
# The Original Code is reddit.
#
# The Original Developer is the Initial Developer.  The Initial Developer of
# the Original Code is reddit Inc.
#
# All portions of the code written by reddit are Copyright (c) 2006-2015 reddit
# Inc. All Rights Reserved.
###############################################################################

import re


class ConfigValue(object):
    _bool_map = dict(true=True, false=False)

    @staticmethod
    def str(v, key=None):
        return str(v)

    @staticmethod
    def int(v, key=None):
        return int(v)

    @staticmethod
    def float(v, key=None):
        return float(v)

    @staticmethod
    def bool(v, key=None):
        if v in (True, False, None):
            return bool(v)
        try:
            return ConfigValue._bool_map[v.lower()]
        except KeyError:
            raise ValueError("Unknown value for %r: %r" % (key, v))

    @staticmethod
    def tuple(v, key=None):
        return tuple(ConfigValue.to_iter(v))

    @staticmethod
    def set(v, key=None):
        return set(ConfigValue.to_iter(v))

    @staticmethod
    def set_of(value_type, delim=','):
        def parse(v, key=None):
            return set(value_type(x)
                       for x in ConfigValue.to_iter(v, delim=delim))
        return parse

    @staticmethod
    def tuple_of(value_type, delim=','):
        def parse(v, key=None):
            return tuple(value_type(x)
                         for x in ConfigValue.to_iter(v, delim=delim))
        return parse

    @staticmethod
    def dict(key_type, value_type, delim=',', kvdelim=':'):
        def parse(v, key=None):
            values = (i.partition(kvdelim)
                      for i in ConfigValue.to_iter(v, delim=delim))
            return {key_type(x): value_type(y) for x, _,  y in values}
        return parse

    @staticmethod
    def choice(**choices):
        def parse_choice(v, key=None):
            try:
                return choices[v]
            except KeyError:
                raise ValueError("Unknown option for %r: %r not in %r" % (key, v, choices.keys()))
        return parse_choice

    @staticmethod
    def to_iter(v, delim = ','):
        return (x.strip() for x in v.split(delim) if x)

    @staticmethod
    def timeinterval(v, key=None):
        # this import is at function level because it relies on the cythonized
        # modules being present which is a problem for plugin __init__s that
        # use this module since they are imported in the early stages of the
        # makefile
        from r2.lib.utils import timeinterval_fromstr
        return timeinterval_fromstr(v)

    messages_re = re.compile(r'"([^"]+)"')
    @staticmethod
    def messages(v, key=None):
        return ConfigValue.messages_re.findall(v.decode("string_escape"))

    @staticmethod
    def baseplate(baseplate_parser):
        def adapter(v, key=None):
            return baseplate_parser(v)
        return adapter


class ConfigValueParser(dict):
    def __init__(self, raw_data):
        dict.__init__(self, raw_data)
        self.config_keys = {}
        self.raw_data = raw_data

    def add_spec(self, spec):
        new_keys = []
        for parser, keys in spec.iteritems():
            # keys can be either a list or a dict
            for key in keys:
                assert key not in self.config_keys
                self.config_keys[key] = parser
                new_keys.append(key)
        self._update_values(new_keys)

    def _update_values(self, keys):
        for key in keys:
            if key not in self.raw_data:
                continue

            value = self.raw_data[key]
            if key in self.config_keys:
                parser = self.config_keys[key]
                value = parser(value, key)
            self[key] = value