codingstatemachine.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')
function CodingStateMachine(sm) {
var self = this;
function init(sm) {
self._mModel = sm;
self._mCurrentBytePos = 0;
self._mCurrentCharLen = 0;
self.reset();
}
this.reset = function() {
this._mCurrentState = constants.start;
}
this.nextState = function(c) {
// for each byte we get its class
// if it is first byte, we also get byte length
var byteCls = this._mModel.classTable[c.charCodeAt(0)];
if( this._mCurrentState == constants.start ) {
this._mCurrentBytePos = 0;
this._mCurrentCharLen = this._mModel.charLenTable[byteCls];
}
// from byte's class and stateTable, we get its next state
this._mCurrentState = this._mModel.stateTable[this._mCurrentState * this._mModel.classFactor + byteCls];
this._mCurrentBytePos++;
return this._mCurrentState;
}
this.getCurrentCharLen = function() {
return this._mCurrentCharLen;
}
this.getCodingStateMachine = function() {
return this._mModel.name;
}
init(sm);
}
module.exports = CodingStateMachine