/* ***** 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>
* Kohei Taketa <k-tak@void.in> (Java 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 ***** */
package org.mozilla.universalchardet.prober;
import java.nio.ByteBuffer;
import org.mozilla.universalchardet.Constants;
public class Latin1Prober extends CharsetProber
{
////////////////////////////////////////////////////////////////
// constants
////////////////////////////////////////////////////////////////
public static final byte UDF = 0;
public static final byte OTH = 1;
public static final byte ASC = 2;
public static final byte ASS = 3;
public static final byte ACV = 4;
public static final byte ACO = 5;
public static final byte ASV = 6;
public static final byte ASO = 7;
public static final int CLASS_NUM = 8;
public static final int FREQ_CAT_NUM = 4;
////////////////////////////////////////////////////////////////
// fields
////////////////////////////////////////////////////////////////
private ProbingState state;
private byte lastCharClass;
private int[] freqCounter;
////////////////////////////////////////////////////////////////
// methods
////////////////////////////////////////////////////////////////
public Latin1Prober()
{
super();
this.freqCounter = new int[FREQ_CAT_NUM];
reset();
}
@Override
public String getCharSetName()
{
return Constants.CHARSET_WINDOWS_1252;
}
@Override
public float getConfidence()
{
if (this.state == ProbingState.NOT_ME) {
return 0.01f;
}
float confidence;
int total = 0;
for (int i=0; i<this.freqCounter.length; ++i) {
total += this.freqCounter[i];
}
if (total <= 0) {
confidence = 0.0f;
} else {
confidence = this.freqCounter[3] * 1.0f / total;
confidence -= this.freqCounter[1] * 20.0f / total;
}
if (confidence < 0.0f) {
confidence = 0.0f;
}
// lower the confidence of latin1 so that other more accurate detector
// can take priority.
confidence *= 0.50f;
return confidence;
}
@Override
public ProbingState getState()
{
return this.state;
}
@Override
public ProbingState handleData(byte[] buf, int offset, int length)
{
ByteBuffer newBufTmp = filterWithEnglishLetters(buf, offset, length);
byte charClass;
byte freq;
byte[] newBuf = newBufTmp.array();
int newBufLen = newBufTmp.position();
for (int i=0; i<newBufLen; ++i) {
int c = newBuf[i] & 0xFF;
charClass = latin1CharToClass[c];
freq = latin1ClassModel[this.lastCharClass * CLASS_NUM + charClass];
if (freq == 0) {
this.state = ProbingState.NOT_ME;
break;
}
++this.freqCounter[freq];
this.lastCharClass = charClass;
}
return this.state;
}
@Override
public void reset()
{
this.state = ProbingState.DETECTING;
this.lastCharClass = OTH;
for (int i=0; i<this.freqCounter.length; ++i) {
this.freqCounter[i] = 0;
}
}
@Override
public void setOption()
{}
////////////////////////////////////////////////////////////////
// constants continued
////////////////////////////////////////////////////////////////
private static final byte[] latin1CharToClass = new byte[] {
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 00 - 07
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 08 - 0F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 10 - 17
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 18 - 1F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 20 - 27
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 28 - 2F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 30 - 37
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 38 - 3F
OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 40 - 47
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 48 - 4F
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 50 - 57
ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH, // 58 - 5F
OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 60 - 67
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 68 - 6F
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 70 - 77
ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH, // 78 - 7F
OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH, // 80 - 87
OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF, // 88 - 8F
UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 90 - 97
OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO, // 98 - 9F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A0 - A7
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A8 - AF
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B0 - B7
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B8 - BF
ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO, // C0 - C7
ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV, // C8 - CF
ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH, // D0 - D7
ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO, // D8 - DF
ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO, // E0 - E7
ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV, // E8 - EF
ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH, // F0 - F7
ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO, // F8 - FF
};
private static final byte[] latin1ClassModel = new byte[] {
/* UDF OTH ASC ASS ACV ACO ASV ASO */
/*UDF*/ 0, 0, 0, 0, 0, 0, 0, 0,
/*OTH*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASC*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASS*/ 0, 3, 3, 3, 1, 1, 3, 3,
/*ACV*/ 0, 3, 3, 3, 1, 2, 1, 2,
/*ACO*/ 0, 3, 3, 3, 3, 3, 3, 3,
/*ASV*/ 0, 3, 1, 3, 1, 1, 1, 3,
/*ASO*/ 0, 3, 1, 3, 1, 1, 3, 3,
};
}
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