jellyfin-server/Emby.Server.Implementations/TextEncoding/UniversalDetector/Core/EscCharsetProber.cs
2019-01-13 21:37:13 +01:00

114 lines
4.3 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 ***** */
namespace UniversalDetector.Core
{
public class EscCharsetProber : CharsetProber
{
private const int CHARSETS_NUM = 4;
private string detectedCharset;
private CodingStateMachine[] codingSM;
int activeSM;
public EscCharsetProber()
{
codingSM = new CodingStateMachine[CHARSETS_NUM];
codingSM[0] = new CodingStateMachine(new HZSMModel());
codingSM[1] = new CodingStateMachine(new ISO2022CNSMModel());
codingSM[2] = new CodingStateMachine(new ISO2022JPSMModel());
codingSM[3] = new CodingStateMachine(new ISO2022KRSMModel());
Reset();
}
public override void Reset()
{
state = ProbingState.Detecting;
for (int i = 0; i < CHARSETS_NUM; i++)
codingSM[i].Reset();
activeSM = CHARSETS_NUM;
detectedCharset = null;
}
public override ProbingState HandleData(byte[] buf, int offset, int len)
{
int max = offset + len;
for (int i = offset; i < max && state == ProbingState.Detecting; i++)
{
for (int j = activeSM - 1; j >= 0; j--)
{
// byte is feed to all active state machine
int codingState = codingSM[j].NextState(buf[i]);
if (codingState == SMModel.ERROR)
{
// got negative answer for this state machine, make it inactive
activeSM--;
if (activeSM == 0)
{
state = ProbingState.NotMe;
return state;
}
else if (j != activeSM)
{
var t = codingSM[activeSM];
codingSM[activeSM] = codingSM[j];
codingSM[j] = t;
}
}
else if (codingState == SMModel.ITSME)
{
state = ProbingState.FoundIt;
detectedCharset = codingSM[j].ModelName;
return state;
}
}
}
return state;
}
public override string GetCharsetName()
{
return detectedCharset;
}
public override float GetConfidence()
{
return 0.99f;
}
}
}