root/branches/libffado-2.0/support/mixer-qt4/ffado_configuration.py

#!/usr/bin/python
#
# Copyright (C) 2008 by Arnold Krille
#
# This file is part of FFADO
# FFADO = Free Firewire (pro-)audio drivers for linux
#
# FFADO is based upon FreeBoB.
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
#

import re, os

import shlex

import logging
log = logging.getLogger('configparser')

class DeviceList:
        def __init__( self, filename="" ):
                self.devices = list()
                if not filename == "":
                        self.updateFromFile( filename )

        def updateFromFile( self, filename, must_exist=False ):
                filename = os.path.expanduser(filename)
                log.debug("DeviceList::updateFromFile(%s)" % filename)
                if not os.path.exists( filename ):
                        if must_exist:
                                log.error("cannot open file")
                        return
                f = open( filename, "r" )

                lex = Parser( f )
                config = {}
                while lex.peaktoken() != lex.eof:
                        tmp = lex.parsenamedvalue()
                        if tmp != None:
                                config[ tmp[0] ] = tmp[1]
                for dev in config["device_definitions"]:
                        self.addDevice( dev )

        def getDeviceById( self, vendor, model ):
                log.debug("DeviceList::getDeviceById( %s, %s )" % (vendor, model ))
                for dev in self.devices:
                        if int("%s" % dev['vendorid'], 0) == int("%s" % vendor, 0) and \
                           int("%s" % dev['modelid'], 0) == int("%s" % model, 0):
                                return dev
                tmp = dict()
                self.devices.append( tmp )
                return tmp

        def addDevice( self, device_dict ):
                log.debug("DeviceList::addDevice()")
                dev = self.getDeviceById( device_dict['vendorid'], device_dict['modelid'] )
                dev.update( device_dict )

class Parser:
        def __init__( self, file ):
                self.lex = shlex.shlex( file )
                self.eof = self.lex.eof

        def peaktoken( self ):
                token = self.lex.get_token()
                self.lex.push_token( token )
                return token

        def parselist( self, level="" ):
                token = self.peaktoken()
                if token != "(":
                        return
                self.lex.get_token()
                log.debug("%sWill parse list" % level)
                ret = []
                token = self.peaktoken()
                while token != ")":
                        ret.append( self.parsenamedvalue( level+"  " ) )
                        token = self.peaktoken()
                log.debug("%slist is %s" % (level, str(ret)))
                self.lex.get_token()
                if self.peaktoken() == ",":
                        log.debug("%sFound a delimiter" % level)
                        self.lex.get_token()
                return ret

        def parsemap( self, level="" ):
                token = self.lex.get_token()
                if token != "{":
                        return
                log.debug("%sWill parse map" % level)
                ret = {}
                token = self.peaktoken()
                while token != "}":
                        #self.push_token( token )
                        tmp = self.parsenamedvalue( level+"  " )
                        if tmp != None:
                                ret[ tmp[0] ] = tmp[1]
                        token = self.peaktoken()
                token = self.lex.get_token()
                log.debug("%sMap ended with '%s' and '%s'"% (level,token,self.peaktoken()))
                if self.peaktoken() in (",",";"):
                        log.debug("%sFound a delimiter!" % level)
                        self.lex.get_token()
                return ret

        def parsevalue( self, level="" ):
                token = self.lex.get_token()
                log.debug("%sparsevalue() called on token '%s'" % (level, token))
                self.lex.push_token( token )
                if token == "(":
                        value = self.parselist( level+"  " )
                elif token == "{":
                        value = self.parsemap( level+"  " )
                else:
                        value = self.lex.get_token().replace( "\"", "" )
                token = self.peaktoken()
                if token == ";":
                        log.debug("%sFound a delimiter!" % level)
                        self.lex.get_token()
                return value

        def parsenamedvalue( self, level="" ):
                token = self.lex.get_token()
                log.debug("%sparsenamedvalue() called on token '%s'" % (level, token))
                if token == "{":
                        self.lex.push_token( token )
                        return self.parsemap( level+"  " )
                if len(token) > 0 and token not in ("{","}","(",")",",",";"):
                        log.debug("%sGot name '%s'" %(level,token))
                        name = token
                        token = self.lex.get_token()
                        if token in ("=",":"):
                                #print "%sWill parse value" % level
                                value = self.parsevalue( level )
                                return (name,value)
                log.debug("%sparsenamedvalue() will return None!" % level)
                return

#
# Have kind of a test directly included...
#
if __name__ == "__main__":

        import sys

        file = sys.argv[1]

        log.setLevel(logging.DEBUG)
        devs = DeviceList( file )

        print devs.devices