mirror of
https://github.com/fofolee/uTools-quickcommand.git
synced 2025-06-09 23:16:18 +08:00
138 lines
5.1 KiB
JavaScript
138 lines
5.1 KiB
JavaScript
/*
|
|
* 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 SingleByteCharSetProber(model, reversed, nameProber) {
|
|
CharSetProber.apply(this);
|
|
|
|
var SAMPLE_SIZE = 64;
|
|
var SB_ENOUGH_REL_THRESHOLD = 1024;
|
|
var POSITIVE_SHORTCUT_THRESHOLD = 0.95;
|
|
var NEGATIVE_SHORTCUT_THRESHOLD = 0.05;
|
|
var SYMBOL_CAT_ORDER = 250;
|
|
var NUMBER_OF_SEQ_CAT = 4;
|
|
var POSITIVE_CAT = NUMBER_OF_SEQ_CAT - 1;
|
|
//var NEGATIVE_CAT = 0;
|
|
|
|
var self = this;
|
|
|
|
function init(model, reversed, nameProber) {
|
|
self._mModel = model;
|
|
self._mReversed = reversed; // "true" if we need to reverse every pair in the model lookup
|
|
self._mNameProber = nameProber; // Optional auxiliary prober for name decision
|
|
self.reset();
|
|
}
|
|
|
|
this.reset = function() {
|
|
SingleByteCharSetProber.prototype.reset.apply(this);
|
|
this._mLastOrder = 255; // char order of last character
|
|
this._mSeqCounters = [];
|
|
for( var i = 0; i < NUMBER_OF_SEQ_CAT; this._mSeqCounters[i++] = 0 );
|
|
this._mTotalSeqs = 0;
|
|
this._mTotalChar = 0;
|
|
this._mFreqChar = 0; // characters that fall in our sampling range
|
|
}
|
|
|
|
this.getCharsetName = function() {
|
|
if( this._mNameProber ) {
|
|
return this._mNameProber.getCharsetName();
|
|
} else {
|
|
return this._mModel.charsetName;
|
|
}
|
|
}
|
|
|
|
this.feed = function(aBuf) {
|
|
if( ! this._mModel.keepEnglishLetter ) {
|
|
aBuf = this.filterWithoutEnglishLetters(aBuf);
|
|
}
|
|
var aLen = aBuf.length;
|
|
if( !aLen ) {
|
|
return this.getState();
|
|
}
|
|
for( var i = 0, c; i < aLen; i++ )
|
|
{
|
|
c = aBuf.charCodeAt(i);
|
|
var order = this._mModel.charToOrderMap[c];
|
|
if( order < SYMBOL_CAT_ORDER ) {
|
|
this._mTotalChar++;
|
|
}
|
|
if( order < SAMPLE_SIZE ) {
|
|
this._mFreqChar++;
|
|
if( this._mLastOrder < SAMPLE_SIZE ) {
|
|
this._mTotalSeqs++;
|
|
if( !this._mReversed ) {
|
|
this._mSeqCounters[this._mModel.precedenceMatrix[(this._mLastOrder * SAMPLE_SIZE) + order]]++;
|
|
} else { // reverse the order of the letters in the lookup
|
|
this._mSeqCounters[this._mModel.precedenceMatrix[(order * SAMPLE_SIZE) + this._mLastOrder]]++;
|
|
}
|
|
}
|
|
}
|
|
this._mLastOrder = order;
|
|
}
|
|
|
|
if( this.getState() == constants.detecting ) {
|
|
if( self._mTotalSeqs > SB_ENOUGH_REL_THRESHOLD ) {
|
|
var cf = this.getConfidence();
|
|
if( cf > POSITIVE_SHORTCUT_THRESHOLD ) {
|
|
logger.log(this._mModel.charsetName + " confidence = " + cf + ", we have a winner\n");
|
|
} else if( cf < NEGATIVE_SHORTCUT_THRESHOLD ) {
|
|
logger.log(this._mModel.charsetName + " confidence = " + cf + ", below negative shortcut threshhold " + NEGATIVE_SHORTCUT_THRESHOLD + "\n");
|
|
this._mState = constants.notMe;
|
|
}
|
|
}
|
|
}
|
|
|
|
return this.getState();
|
|
}
|
|
|
|
this.getConfidence = function() {
|
|
var r = 0.01;
|
|
if( this._mTotalSeqs > 0 ) {
|
|
//logger.log(this._mSeqCounters[POSITIVE_CAT] + " " + this._mTotalSeqs + " " + this._mModel.mTypicalPositiveRatio);
|
|
r = (1.0 * this._mSeqCounters[POSITIVE_CAT]) / this._mTotalSeqs / this._mModel.mTypicalPositiveRatio;
|
|
//logger.log(r + " " + this._mFreqChar + " " + this._mTotalChar);
|
|
r *= this._mFreqChar / this._mTotalChar;
|
|
if( r >= 1.0 ) {
|
|
r = 0.99;
|
|
}
|
|
}
|
|
return r;
|
|
}
|
|
|
|
reversed = reversed !== undefined ? reversed : false;
|
|
nameProber = nameProber !== undefined ? nameProber : null;
|
|
init(model, reversed, nameProber);
|
|
}
|
|
SingleByteCharSetProber.prototype = new CharSetProber();
|
|
|
|
module.exports = SingleByteCharSetProber
|