mbcharsetprober.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 CharSetProber = require('./charsetprober');
var constants = require('./constants');
var logger = require('./logger');
function MultiByteCharSetProber() {
CharSetProber.apply(this);
var self = this;
function init() {
self._mDistributionAnalyzer = null;
self._mCodingSM = null;
//self._mLastChar = ["\x00", "\x00"];
self._mLastChar = "\x00\x00";
}
this.reset = function() {
MultiByteCharSetProber.prototype.reset.apply(this);
if( this._mCodingSM ) {
this._mCodingSM.reset();
}
if( this._mDistributionAnalyzer ) {
this._mDistributionAnalyzer.reset();
}
//this._mLastChar = ["\x00", "\x00"];
this._mLastChar = "\x00\x00";
}
this.getCharsetName = function() {
}
this.feed = function(aBuf) {
var aLen = aBuf.length;
for( var i = 0; i < aLen; i++ ) {
var codingState = this._mCodingSM.nextState(aBuf[i]);
if( codingState == constants.error ) {
logger.log(this.getCharsetName() + " prober hit error at byte " + i + "\n");
this._mState = constants.notMe;
break;
} else if( codingState == constants.itsMe ) {
this._mState = constants.foundIt;
break;
} else if( codingState == constants.start ) {
var charLen = this._mCodingSM.getCurrentCharLen();
if( i == 0 ) {
this._mLastChar[1] = aBuf[0];
this._mDistributionAnalyzer.feed(this._mLastChar, charLen);
} else {
this._mDistributionAnalyzer.feed(aBuf.slice(i-1,i+1), charLen);
}
}
}
this._mLastChar[0] = aBuf[aLen - 1];
if( this.getState() == constants.detecting ) {
if( this._mDistributionAnalyzer.gotEnoughData() &&
this.getConfidence() > constants.SHORTCUT_THRESHOLD ) {
this._mState = constants.foundIt;
}
}
return this.getState();
}
this.getConfidence = function() {
return this._mDistributionAnalyzer.getConfidence();
}
}
MultiByteCharSetProber.prototype = new CharSetProber();
module.exports = MultiByteCharSetProber