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# ***** BEGIN LICENSE BLOCK ***** 

# Version: MPL 1.1/GPL 2.0/LGPL 2.1 

# 

# The contents of this file are subject to the Mozilla Public License Version 

# 1.1 (the "License"); you may not use this file except in compliance with 

# the License. You may obtain a copy of the License at 

# http://www.mozilla.org/MPL/ 

# 

# 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 configman 

# 

# The Initial Developer of the Original Code is 

# Mozilla Foundation 

# Portions created by the Initial Developer are Copyright (C) 2011 

# the Initial Developer. All Rights Reserved. 

# 

# Contributor(s): 

#    K Lars Lohn, lars@mozilla.com 

#    Peter Bengtsson, peterbe@mozilla.com 

# 

# Alternatively, the contents of this file may be used under the terms of 

# either the GNU General Public License Version 2 or later (the "GPL"), or 

# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), 

# in which case the provisions of the GPL or the LGPL are applicable instead 

# of those above. If you wish to allow use of your version of this file only 

# under the terms of either the GPL or the LGPL, and not to allow others to 

# use your version of this file under the terms of the MPL, indicate your 

# decision by deleting the provisions above and replace them with the notice 

# and other provisions required by the GPL or the LGPL. If you do not delete 

# the provisions above, a recipient may use your version of this file under 

# the terms of any one of the MPL, the GPL or the LGPL. 

# 

# ***** END LICENSE BLOCK ***** 

 

"""This module implements a configuration value source comprising a stream of 

textual key/value pairs.  The implementation uses a ContextManger to iterate 

through the stream.  The ContextManager can represent any number of sources, 

like files or database results.  If supplied with a simple string rather than 

a ContextManager, the value source will assume it is a file pathname and try 

to open it. 

""" 

 

import functools 

import sys 

 

from .. import namespace 

from .. import option as opt 

from .. import converters as conv 

 

from source_exceptions import ValueException, CantHandleTypeException 

 

function_type = type(lambda x: x)  # TODO: just how do you express the Fuction 

                                   # type as a constant? 

                                   # (peter: why not use inspect.isfunction()?) 

 

# the list of types that the contstuctor can handle. 

can_handle = (basestring, 

              function_type  # this is to say that this ValueSource is willing 

                             # to try a function that will return a 

                             # context manager 

             ) 

 

file_name_extension = 'conf' 

 

 

class NotAConfigFileError(ValueException): 

    pass 

 

 

class ValueSource(object): 

 

    def __init__(self, candidate, the_config_manager=None): 

        if (isinstance(candidate, basestring) and 

            candidate.endswith(file_name_extension)): 

            # we're trusting the string represents a filename 

            opener = functools.partial(open, candidate) 

        elif isinstance(candidate, function_type): 

            # we're trusting that the function when called with no parameters 

            # will return a Context Manager Type. 

            opener = candidate 

        else: 

            raise CantHandleTypeException("don't know how to handle" 

                                                     " %s." % str(candidate)) 

        self.values = {} 

        try: 

            with opener() as f: 

                previous_key = None 

                for line in f: 

                    if line.strip().startswith('#') or not line.strip(): 

                        continue 

                    if line[0] in ' \t' and previous_key: 

                        line = line[1:] 

                        self.values[previous_key] = '%s%s' % \ 

                                            (self.values[previous_key], 

                                             line.rstrip()) 

                        continue 

                    try: 

                        key, value = line.split("=", 1) 

                        self.values[key.strip()] = value.strip() 

                        previous_key = key 

                    except ValueError: 

                        self.values[line] = '' 

        except Exception, x: 

            raise NotAConfigFileError("couldn't interpret %s as a context " 

                                          "file: %s" % (candidate, str(x))) 

 

    def get_values(self, config_manager, ignore_mismatches): 

        """the 'config_manager' and 'ignore_mismatches' are dummy values for 

        this implementation of a ValueSource.""" 

        return self.values 

 

    @staticmethod 

    def write(option_iter, output_stream=sys.stdout, comments=True): 

        for qkey, key, val in option_iter(): 

            if isinstance(val, namespace.Namespace): 

                print >> output_stream, '#%s' % ('-' * 79) 

                print >> output_stream, '# %s - %s\n' % (key, val._doc) 

            elif isinstance(val, opt.Option): 

                if comments: 

                    print >> output_stream, '# name:', qkey 

                    print >> output_stream, '# doc:', val.doc 

                    print >> output_stream, '# converter:', \ 

                        conv.py_obj_to_str(val.from_string_converter) 

                val_str = conv.option_value_str(val) 

                print >> output_stream, '%s=%s\n' % (qkey, val_str) 

            elif isinstance(val, opt.Aggregation): 

                # there is nothing to do for Aggregations at this time 

                # it appears here anyway as a marker for future enhancements 

                pass