1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/extensions/universalchardet/src/base/nsLatin1Prober.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,149 @@
1.4 +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsLatin1Prober.h"
1.10 +#include "prmem.h"
1.11 +#include <stdio.h>
1.12 +
1.13 +#define UDF 0 // undefined
1.14 +#define OTH 1 //other
1.15 +#define ASC 2 // ascii capital letter
1.16 +#define ASS 3 // ascii small letter
1.17 +#define ACV 4 // accent capital vowel
1.18 +#define ACO 5 // accent capital other
1.19 +#define ASV 6 // accent small vowel
1.20 +#define ASO 7 // accent small other
1.21 +#define CLASS_NUM 8 // total classes
1.22 +
1.23 +static const unsigned char Latin1_CharToClass[] =
1.24 +{
1.25 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 00 - 07
1.26 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 08 - 0F
1.27 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 10 - 17
1.28 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 18 - 1F
1.29 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 20 - 27
1.30 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 28 - 2F
1.31 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 30 - 37
1.32 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 38 - 3F
1.33 + OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 40 - 47
1.34 + ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 48 - 4F
1.35 + ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, // 50 - 57
1.36 + ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH, // 58 - 5F
1.37 + OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 60 - 67
1.38 + ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 68 - 6F
1.39 + ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, // 70 - 77
1.40 + ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH, // 78 - 7F
1.41 + OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH, // 80 - 87
1.42 + OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF, // 88 - 8F
1.43 + UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // 90 - 97
1.44 + OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO, // 98 - 9F
1.45 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A0 - A7
1.46 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // A8 - AF
1.47 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B0 - B7
1.48 + OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, // B8 - BF
1.49 + ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO, // C0 - C7
1.50 + ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV, // C8 - CF
1.51 + ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH, // D0 - D7
1.52 + ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO, // D8 - DF
1.53 + ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO, // E0 - E7
1.54 + ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV, // E8 - EF
1.55 + ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH, // F0 - F7
1.56 + ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO, // F8 - FF
1.57 +};
1.58 +
1.59 +
1.60 +/* 0 : illegal
1.61 + 1 : very unlikely
1.62 + 2 : normal
1.63 + 3 : very likely
1.64 +*/
1.65 +static const unsigned char Latin1ClassModel[] =
1.66 +{
1.67 +/* UDF OTH ASC ASS ACV ACO ASV ASO */
1.68 +/*UDF*/ 0, 0, 0, 0, 0, 0, 0, 0,
1.69 +/*OTH*/ 0, 3, 3, 3, 3, 3, 3, 3,
1.70 +/*ASC*/ 0, 3, 3, 3, 3, 3, 3, 3,
1.71 +/*ASS*/ 0, 3, 3, 3, 1, 1, 3, 3,
1.72 +/*ACV*/ 0, 3, 3, 3, 1, 2, 1, 2,
1.73 +/*ACO*/ 0, 3, 3, 3, 3, 3, 3, 3,
1.74 +/*ASV*/ 0, 3, 1, 3, 1, 1, 1, 3,
1.75 +/*ASO*/ 0, 3, 1, 3, 1, 1, 3, 3,
1.76 +};
1.77 +
1.78 +void nsLatin1Prober::Reset(void)
1.79 +{
1.80 + mState = eDetecting;
1.81 + mLastCharClass = OTH;
1.82 + for (int i = 0; i < FREQ_CAT_NUM; i++)
1.83 + mFreqCounter[i] = 0;
1.84 +}
1.85 +
1.86 +
1.87 +nsProbingState nsLatin1Prober::HandleData(const char* aBuf, uint32_t aLen)
1.88 +{
1.89 + char *newBuf1 = 0;
1.90 + uint32_t newLen1 = 0;
1.91 +
1.92 + if (!FilterWithEnglishLetters(aBuf, aLen, &newBuf1, newLen1)) {
1.93 + newBuf1 = (char*)aBuf;
1.94 + newLen1 = aLen;
1.95 + }
1.96 +
1.97 + unsigned char charClass;
1.98 + unsigned char freq;
1.99 + for (uint32_t i = 0; i < newLen1; i++)
1.100 + {
1.101 + charClass = Latin1_CharToClass[(unsigned char)newBuf1[i]];
1.102 + freq = Latin1ClassModel[mLastCharClass*CLASS_NUM + charClass];
1.103 + if (freq == 0) {
1.104 + mState = eNotMe;
1.105 + break;
1.106 + }
1.107 + mFreqCounter[freq]++;
1.108 + mLastCharClass = charClass;
1.109 + }
1.110 +
1.111 + if (newBuf1 != aBuf)
1.112 + PR_FREEIF(newBuf1);
1.113 +
1.114 + return mState;
1.115 +}
1.116 +
1.117 +float nsLatin1Prober::GetConfidence(void)
1.118 +{
1.119 + if (mState == eNotMe)
1.120 + return 0.01f;
1.121 +
1.122 + float confidence;
1.123 + uint32_t total = 0;
1.124 + for (int32_t i = 0; i < FREQ_CAT_NUM; i++)
1.125 + total += mFreqCounter[i];
1.126 +
1.127 + if(!total)
1.128 + confidence = 0.0f;
1.129 + else
1.130 + {
1.131 + confidence = mFreqCounter[3]*1.0f / total;
1.132 + confidence -= mFreqCounter[1]*20.0f/total;
1.133 + }
1.134 +
1.135 + if (confidence < 0.0f)
1.136 + confidence = 0.0f;
1.137 +
1.138 + // lower the confidence of latin1 so that other more accurate detector
1.139 + // can take priority.
1.140 + confidence *= 0.50f;
1.141 +
1.142 + return confidence;
1.143 +}
1.144 +
1.145 +#ifdef DEBUG_chardet
1.146 +void nsLatin1Prober::DumpStatus()
1.147 +{
1.148 + printf(" Latin1Prober: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
1.149 +}
1.150 +#endif
1.151 +
1.152 +
