charsetgroupprober.js
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/*
* The Original Code is Mozilla Universal charset detector code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2001
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* António Afonso (antonio.afonso gmail.com) - port to JavaScript
* Mark Pilgrim - port to Python
* Shy Shalom - original C code
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
var constants = require('./constants');
var CharSetProber = require('./charsetprober');
var logger = require('./logger');
function CharSetGroupProber() {
CharSetProber.apply(this);
var self = this;
function init() {
self._mActiveNum = 0;
self._mProbers = [];
self._mBestGuessProber = null;
}
this.reset = function() {
CharSetGroupProber.prototype.reset.apply(this);
this._mActiveNum = 0;
for( var i = 0, prober; prober = this._mProbers[i]; i++ ) {
if( prober ) {
prober.reset();
prober.active = true;
this._mActiveNum++;
}
}
this._mBestGuessProber = null;
}
this.getCharsetName = function() {
if( !this._mBestGuessProber ) {
this.getConfidence();
if( !this._mBestGuessProber ) return null;
}
return this._mBestGuessProber.getCharsetName();
}
this.feed = function(aBuf) {
for( var i = 0, prober; prober = this._mProbers[i]; i++ ) {
if( !prober || !prober.active ) continue;
var st = prober.feed(aBuf);
if( !st ) continue;
if( st == constants.foundIt ) {
this._mBestGuessProber = prober;
return this.getState();
} else if( st == constants.notMe ) {
prober.active = false;
this._mActiveNum--;
if( this._mActiveNum <= 0 ) {
this._mState = constants.notMe;
return this.getState();
}
}
}
return this.getState();
}
this.getConfidence = function() {
var st = this.getState();
if( st == constants.foundIt ) {
return 0.99;
} else if( st == constants.notMe ) {
return 0.01;
}
var bestConf = 0.0;
this._mBestGuessProber = null;
for( var i = 0, prober; prober = this._mProbers[i]; i++ ) {
if( !prober ) continue;
if( !prober.active ) {
logger.log(prober.getCharsetName() + " not active\n");
continue;
}
var cf = prober.getConfidence();
logger.log(prober.getCharsetName() + " confidence = " + cf + "\n");
if( bestConf < cf ) {
bestConf = cf;
this._mBestGuessProber = prober;
}
}
if( !this._mBestGuessProber ) return 0.0;
return bestConf;
}
init();
}
CharSetGroupProber.prototype = new CharSetProber();
module.exports = CharSetGroupProber