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#
# Copyright 2008 Sun Microsystems, Inc. All rights reserved.
# Use is subject to license terms.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301 USA.
#
import os
_parsers = [ ]
class parser(object):
"""
Base class for particular config file format definitions of
a VM instance.
Warning: this interface is not (yet) considered stable and may
change at will.
"""
@staticmethod
def identify_file(input_file):
"""
Return True if the given file is of this format.
"""
raise NotImplementedError
@staticmethod
def import_file(input_file):
"""
Import a configuration file. Raises if the file couldn't be
opened, or parsing otherwise failed.
"""
raise NotImplementedError
@staticmethod
def export(vm):
"""
Export a configuration file as a string.
@vm vm configuration instance
Raises ValueError if configuration is not suitable.
"""
raise NotImplementedError
def register_parser(new_parser):
"""
Register a particular config format parser. This should be called by each
config plugin on import.
"""
global _parsers
_parsers += [ new_parser ]
def parser_by_name(name):
"""
Return the parser of the given name.
"""
parsers = [p for p in _parsers if p.name == name]
if len(parsers):
return parsers[0]
def find_parser_by_file(input_file):
"""
Return the parser that is capable of comprehending the given file.
"""
for p in _parsers:
if p.identify_file(input_file):
return p
return None
def formats():
"""
Return a list of supported formats.
"""
return [p.name for p in _parsers]
def input_formats():
"""
Return a list of supported input formats.
"""
return [p.name for p in _parsers if p.can_import]
def output_formats():
"""
Return a list of supported output formats.
"""
return [p.name for p in _parsers if p.can_export]
def find_input(path, format=None):
"""
Search for a configuration file automatically. If @format is given,
then only search using a matching format parser.
"""
if os.path.isdir(path):
files = os.listdir(path)
for p in _parsers:
if not p.can_identify:
continue
if format and format != p.name:
continue
if os.path.isfile(path):
if p.identify_file(path):
return (path, p.name)
elif os.path.isdir(path):
for cfgfile in [ x for x in files if x.endswith(p.suffix) ]:
if p.identify_file(os.path.join(path, cfgfile)):
return (os.path.join(path, cfgfile), p.name)
raise StandardError(_("Unknown format"))
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