jellyfin-server/Emby.Common.Implementations/TextEncoding/UniversalDetector/Core/SBCSGroupProber.cs
2017-04-18 01:53:39 -04:00

181 lines
7.2 KiB
C#

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* 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):
* Shy Shalom <shooshX@gmail.com>
* Rudi Pettazzi <rudi.pettazzi@gmail.com> (C# port)
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
using System;
namespace UniversalDetector.Core
{
public class SBCSGroupProber : CharsetProber
{
private const int PROBERS_NUM = 13;
private CharsetProber[] probers = new CharsetProber[PROBERS_NUM];
private bool[] isActive = new bool[PROBERS_NUM];
private int bestGuess;
private int activeNum;
public SBCSGroupProber()
{
probers[0] = new SingleByteCharSetProber(new Win1251Model());
probers[1] = new SingleByteCharSetProber(new Koi8rModel());
probers[2] = new SingleByteCharSetProber(new Latin5Model());
probers[3] = new SingleByteCharSetProber(new MacCyrillicModel());
probers[4] = new SingleByteCharSetProber(new Ibm866Model());
probers[5] = new SingleByteCharSetProber(new Ibm855Model());
probers[6] = new SingleByteCharSetProber(new Latin7Model());
probers[7] = new SingleByteCharSetProber(new Win1253Model());
probers[8] = new SingleByteCharSetProber(new Latin5BulgarianModel());
probers[9] = new SingleByteCharSetProber(new Win1251BulgarianModel());
HebrewProber hebprober = new HebrewProber();
probers[10] = hebprober;
// Logical
probers[11] = new SingleByteCharSetProber(new Win1255Model(), false, hebprober);
// Visual
probers[12] = new SingleByteCharSetProber(new Win1255Model(), true, hebprober);
hebprober.SetModelProbers(probers[11], probers[12]);
// disable latin2 before latin1 is available, otherwise all latin1
// will be detected as latin2 because of their similarity.
//probers[13] = new SingleByteCharSetProber(new Latin2HungarianModel());
//probers[14] = new SingleByteCharSetProber(new Win1250HungarianModel());
Reset();
}
public override ProbingState HandleData(byte[] buf, int offset, int len)
{
ProbingState st = ProbingState.NotMe;
//apply filter to original buffer, and we got new buffer back
//depend on what script it is, we will feed them the new buffer
//we got after applying proper filter
//this is done without any consideration to KeepEnglishLetters
//of each prober since as of now, there are no probers here which
//recognize languages with English characters.
byte[] newBuf = FilterWithoutEnglishLetters(buf, offset, len);
if (newBuf.Length == 0)
return state; // Nothing to see here, move on.
for (int i = 0; i < PROBERS_NUM; i++) {
if (!isActive[i])
continue;
st = probers[i].HandleData(newBuf, 0, newBuf.Length);
if (st == ProbingState.FoundIt) {
bestGuess = i;
state = ProbingState.FoundIt;
break;
} else if (st == ProbingState.NotMe) {
isActive[i] = false;
activeNum--;
if (activeNum <= 0) {
state = ProbingState.NotMe;
break;
}
}
}
return state;
}
public override float GetConfidence()
{
float bestConf = 0.0f, cf;
switch (state) {
case ProbingState.FoundIt:
return 0.99f; //sure yes
case ProbingState.NotMe:
return 0.01f; //sure no
default:
for (int i = 0; i < PROBERS_NUM; i++)
{
if (!isActive[i])
continue;
cf = probers[i].GetConfidence();
if (bestConf < cf)
{
bestConf = cf;
bestGuess = i;
}
}
break;
}
return bestConf;
}
public override void DumpStatus()
{
float cf = GetConfidence();
// Console.WriteLine(" SBCS Group Prober --------begin status");
for (int i = 0; i < PROBERS_NUM; i++) {
if (isActive[i])
probers[i].DumpStatus();
//else
//Console.WriteLine(" inactive: [{0}] (i.e. confidence is too low).", probers[i].GetCharsetName());
}
//Console.WriteLine(" SBCS Group found best match [{0}] confidence {1}.", probers[bestGuess].GetCharsetName(), cf);
}
public override void Reset ()
{
int activeNum = 0;
for (int i = 0; i < PROBERS_NUM; i++) {
if (probers[i] != null) {
probers[i].Reset();
isActive[i] = true;
activeNum++;
} else {
isActive[i] = false;
}
}
bestGuess = -1;
state = ProbingState.Detecting;
}
public override string GetCharsetName()
{
//if we have no answer yet
if (bestGuess == -1) {
GetConfidence();
//no charset seems positive
if (bestGuess == -1)
bestGuess = 0;
}
return probers[bestGuess].GetCharsetName();
}
}
}