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

91 lines
3.2 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.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Shy Shalom <shooshX@gmail.com>
* Kohei TAKETA <k-tak@void.in> (Java port)
* Rudi Pettazzi <rudi.pettazzi@gmail.com> (C# port)
*
* Alternatively, the contents of this file may be used under the terms of
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* 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
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* ***** END LICENSE BLOCK ***** */
namespace UniversalDetector.Core
{
/// <summary>
/// Parallel state machine for the Coding Scheme Method
/// </summary>
public class CodingStateMachine
{
private int currentState;
private SMModel model;
private int currentCharLen;
private int currentBytePos;
public CodingStateMachine(SMModel model)
{
this.currentState = SMModel.START;
this.model = model;
}
public int NextState(byte b)
{
// for each byte we get its class, if it is first byte,
// we also get byte length
int byteCls = model.GetClass(b);
if (currentState == SMModel.START) {
currentBytePos = 0;
currentCharLen = model.charLenTable[byteCls];
}
// from byte's class and stateTable, we get its next state
currentState = model.stateTable.Unpack(
currentState * model.ClassFactor + byteCls);
currentBytePos++;
return currentState;
}
public void Reset()
{
currentState = SMModel.START;
}
public int CurrentCharLen
{
get { return currentCharLen; }
}
public string ModelName
{
get { return model.Name; }
}
}
}