1 : /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is Mozilla Universal charset detector code.
16 : *
17 : * The Initial Developer of the Original Code is
18 : * Netscape Communications Corporation.
19 : * Portions created by the Initial Developer are Copyright (C) 2001
20 : * the Initial Developer. All Rights Reserved.
21 : *
22 : * Contributor(s):
23 : * Shy Shalom <shooshX@gmail.com>
24 : *
25 : * Alternatively, the contents of this file may be used under the terms of
26 : * either the GNU General Public License Version 2 or later (the "GPL"), or
27 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
28 : * in which case the provisions of the GPL or the LGPL are applicable instead
29 : * of those above. If you wish to allow use of your version of this file only
30 : * under the terms of either the GPL or the LGPL, and not to allow others to
31 : * use your version of this file under the terms of the MPL, indicate your
32 : * decision by deleting the provisions above and replace them with the notice
33 : * and other provisions required by the GPL or the LGPL. If you do not delete
34 : * the provisions above, a recipient may use your version of this file under
35 : * the terms of any one of the MPL, the GPL or the LGPL.
36 : *
37 : * ***** END LICENSE BLOCK ***** */
38 : #include <stdio.h>
39 : #include "nsSBCharSetProber.h"
40 :
41 0 : nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32 aLen)
42 : {
43 : unsigned char order;
44 :
45 0 : for (PRUint32 i = 0; i < aLen; i++)
46 : {
47 0 : order = mModel->charToOrderMap[(unsigned char)aBuf[i]];
48 :
49 0 : if (order < SYMBOL_CAT_ORDER)
50 0 : mTotalChar++;
51 0 : if (order < SAMPLE_SIZE)
52 : {
53 0 : mFreqChar++;
54 :
55 0 : if (mLastOrder < SAMPLE_SIZE)
56 : {
57 0 : mTotalSeqs++;
58 0 : if (!mReversed)
59 0 : ++(mSeqCounters[mModel->precedenceMatrix[mLastOrder*SAMPLE_SIZE+order]]);
60 : else // reverse the order of the letters in the lookup
61 0 : ++(mSeqCounters[mModel->precedenceMatrix[order*SAMPLE_SIZE+mLastOrder]]);
62 : }
63 : }
64 0 : mLastOrder = order;
65 : }
66 :
67 0 : if (mState == eDetecting)
68 0 : if (mTotalSeqs > SB_ENOUGH_REL_THRESHOLD)
69 : {
70 0 : float cf = GetConfidence();
71 0 : if (cf > POSITIVE_SHORTCUT_THRESHOLD)
72 0 : mState = eFoundIt;
73 0 : else if (cf < NEGATIVE_SHORTCUT_THRESHOLD)
74 0 : mState = eNotMe;
75 : }
76 :
77 0 : return mState;
78 : }
79 :
80 0 : void nsSingleByteCharSetProber::Reset(void)
81 : {
82 0 : mState = eDetecting;
83 0 : mLastOrder = 255;
84 0 : for (PRUint32 i = 0; i < NUMBER_OF_SEQ_CAT; i++)
85 0 : mSeqCounters[i] = 0;
86 0 : mTotalSeqs = 0;
87 0 : mTotalChar = 0;
88 0 : mFreqChar = 0;
89 0 : }
90 :
91 : //#define NEGATIVE_APPROACH 1
92 :
93 0 : float nsSingleByteCharSetProber::GetConfidence(void)
94 : {
95 : #ifdef NEGATIVE_APPROACH
96 : if (mTotalSeqs > 0)
97 : if (mTotalSeqs > mSeqCounters[NEGATIVE_CAT]*10 )
98 : return ((float)(mTotalSeqs - mSeqCounters[NEGATIVE_CAT]*10))/mTotalSeqs * mFreqChar / mTotalChar;
99 : return (float)0.01;
100 : #else //POSITIVE_APPROACH
101 : float r;
102 :
103 0 : if (mTotalSeqs > 0) {
104 0 : r = ((float)1.0) * mSeqCounters[POSITIVE_CAT] / mTotalSeqs / mModel->mTypicalPositiveRatio;
105 0 : r = r*mFreqChar/mTotalChar;
106 0 : if (r >= (float)1.00)
107 0 : r = (float)0.99;
108 0 : return r;
109 : }
110 0 : return (float)0.01;
111 : #endif
112 : }
113 :
114 0 : const char* nsSingleByteCharSetProber::GetCharSetName()
115 : {
116 0 : if (!mNameProber)
117 0 : return mModel->charsetName;
118 0 : return mNameProber->GetCharSetName();
119 : }
120 :
121 : #ifdef DEBUG_chardet
122 : void nsSingleByteCharSetProber::DumpStatus()
123 : {
124 : printf(" SBCS: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
125 : }
126 : #endif
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