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/* ***** 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
{
/// <summary>
/// Multi-byte charsets probers
/// </summary>
public class MBCSGroupProber : CharsetProber
{
private const int PROBERS_NUM = 7;
private readonly static string[] ProberName =
{ "UTF8", "SJIS", "EUCJP", "GB18030", "EUCKR", "Big5", "EUCTW" };
private CharsetProber[] probers = new CharsetProber[PROBERS_NUM];
private bool[] isActive = new bool[PROBERS_NUM];
private int bestGuess;
private int activeNum;
public MBCSGroupProber()
{
probers[0] = new UTF8Prober();
probers[1] = new SJISProber();
probers[2] = new EUCJPProber();
probers[3] = new GB18030Prober();
probers[4] = new EUCKRProber();
probers[5] = new Big5Prober();
probers[6] = new EUCTWProber();
Reset();
}
public override string GetCharsetName()
{
if (bestGuess == -1) {
GetConfidence();
if (bestGuess == -1)
bestGuess = 0;
}
return probers[bestGuess].GetCharsetName();
}
public override void Reset()
{
activeNum = 0;
for (int i = 0; i < probers.Length; i++) {
if (probers[i] != null) {
probers[i].Reset();
isActive[i] = true;
++activeNum;
} else {
isActive[i] = false;
}
}
bestGuess = -1;
state = ProbingState.Detecting;
}
public override ProbingState HandleData(byte[] buf, int offset, int len)
{
// do filtering to reduce load to probers
byte[] highbyteBuf = new byte[len];
int hptr = 0;
//assume previous is not ascii, it will do no harm except add some noise
bool keepNext = true;
int max = offset + len;
for (int i = offset; i < max; i++) {
if ((buf[i] & 0x80) != 0) {
highbyteBuf[hptr++] = buf[i];
keepNext = true;
} else {
//if previous is highbyte, keep this even it is a ASCII
if (keepNext) {
highbyteBuf[hptr++] = buf[i];
keepNext = false;
}
}
}
ProbingState st = ProbingState.NotMe;
for (int i = 0; i < probers.Length; i++) {
if (!isActive[i])
continue;
st = probers[i].HandleData(highbyteBuf, 0, hptr);
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;
float cf = 0.0f;
if (state == ProbingState.FoundIt) {
return 0.99f;
} else if (state == ProbingState.NotMe) {
return 0.01f;
} else {
for (int i = 0; i < PROBERS_NUM; i++) {
if (!isActive[i])
continue;
cf = probers[i].GetConfidence();
if (bestConf < cf) {
bestConf = cf;
bestGuess = i;
}
}
}
return bestConf;
}
public override void DumpStatus()
{
float cf;
GetConfidence();
for (int i = 0; i < PROBERS_NUM; i++) {
if (!isActive[i]) {
//Console.WriteLine(" MBCS inactive: {0} (confidence is too low).", ProberName[i]);
} else {
cf = probers[i].GetConfidence();
//Console.WriteLine(" MBCS {0}: [{1}]", cf, ProberName[i]);
}
}
}
}
}
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