boinc/sched/boinc_config.py

#!/usr/bin/env python

# $Id$

# boinc_config.py - module to read config.xml

# The contents of this file are subject to the BOINC Public 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:#boinc.berkeley.edu/license_1.0.txt
#
# 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 the Berkeley Open Infrastructure for Network Computing.
#
# The Initial Developer of the Original Code is the SETI@home project.
# Portions created by the SETI@home project are Copyright (C) 2002
# University of California at Berkeley. All Rights Reserved.
#
# Contributor(s):
#

## SYNOPSIS:  parses config.xml

## USAGE:     from boinc_config import config
#             config.read()
#             print config.config.db_name
#             print config.tasks[4].cmd
#             config.enabled = True
#             boinc_config.config.write()

# TODO: create a Boinc package and remove these Boinc prefix qualifiers

import sys
import xml.dom.minidom

CONFIG_FILE = '../config.xml'

def _get_elements(node, name):
    return node.getElementsByTagName(name)

def _get_element(node, name, optional=False):
    try:
        return _get_elements(node,name)[0]
    except IndexError:
        if optional:
            new_element = xml.dom.minidom.Element(name)
            node.appendChild(new_element)
            return new_element
        raise SystemExit("ERROR: Couldn't find xml node <%s>"% name)

def _get_element_data(node):
    return node and node.firstChild and node.firstChild.data

def _get_element_int(node, default=0):
    try:
        return int(_get_element_data(node))
    except:
        return default

def _get_child_elements(node):
    return filter(lambda node: node.nodeType == node.ELEMENT_NODE, node.childNodes)

def _set_element(node, new_data):
    if node.firstChild and node.firstChild.data:
        node.firstChild.data = str(new_data)
    else:
        new_data_node = xml.dom.minidom.Text()
        new_data_node.data = str(new_data)
        node.appendChild(new_data_node)

class ConfigDict:
    def __init__(self, dom_node):
        self.node = dom_node
        for node in _get_child_elements(self.node):
            self.__dict__[node.nodeName] = _get_element_data(node)
    def save(self):
        for key in self.__dict__:
            _set_element( _get_element(self.node,key,1), str(self.__dict__[key]) )
    def debug_print(self):
        for key in self.__dict__.keys():
            print key.rjust(15), '=', self.__dict__[key]

def newConfigDict(name):
    return ConfigDict(xml.dom.minidom.Element(name))

class ConfigDictList(list):
    def __init__(self, dom_node):
        self.node = dom_node
        list.__init__(self, map(ConfigDict, _get_child_elements(self.node)))
    def save(self):
        map(ConfigDict.save, self)
    def append(self, cd):
        list.append(self, cd)
        self.node.appendChild(cd.node)
    def make_node_and_append(self, name):
        '''Make a new ConfigDict and append it. Returns new ConfigDict.'''
        cd = newConfigDict(name)
        self.append(cd)
        return cd

class XMLConfig:
    def __init__(self, filename):
        self.filename = filename
    def read(self):
        self.xml     = xml.dom.minidom.parse(open(self.filename))
        self._get_elements()
        return self
    def _get_elements(self):
        pass
    def write(self):
        self._set_elements()
        self.xml.writexml(open(self.filename,'w'))
        return self
    def _set_elements(self):
        pass

class BoincConfig(XMLConfig):
    def _get_elements(self):
        self.xml_boinc   = _get_element(self.xml,  'boinc')
        self.xml_config  = _get_element(self.xml_boinc, 'config')
        self.xml_tasks   = _get_element(self.xml_boinc, 'tasks')
        self.xml_enabled = _get_element(self.xml_boinc, 'enabled', optional=1)
        self.enabled     = _get_element_int(self.xml_enabled)
        self.config      = ConfigDict(self.xml_config)
        self.tasks       = ConfigDictList(self.xml_tasks)
    def _set_elements(self):
        _set_element( self.xml_enabled, self.enabled )
        self.config.save()
        self.tasks.save()

    def debug_print_all(self):
        '''print everything to stdout.'''

        print 'Debug dump of', self.filename
        print '-- parsed xml -------------------------------------------------------'
        self.xml.writexml(sys.stdout)
        print
        print '-- Enabled =', self.enabled
        print '-- Config -----------------------------------------------------------'
        self.config.debug_print()
        print
        print '-- Tasks ------------------------------------------------------------'
        for task in self.tasks:
            task.debug_print()
            print

class BoincCronStatus(XMLConfig):
    def _get_elements(self):
        self.xml_boinc    = _get_element(self.xml,  'boinc')
        self.xml_tasks    = _get_element(self.xml_boinc, 'tasks')
        self.tasks        = ConfigDictList(self.xml_tasks)
    def _set_elements(self):
        self.tasks.save()

# don't read config by default, so that user could see help message even if
# config doesn't load correctly.
config = BoincConfig(CONFIG_FILE)

if __name__ == '__main__':
    config.read()
    config.debug_print_all()
    config.write()