1 /* 2 ********************************************************************** 3 * Copyright (C) 2005-2012, International Business Machines 4 * Corporation and others. All Rights Reserved. 5 ********************************************************************** 6 */ 7 8 #include "unicode/utypes.h" 9 10 #if !UCONFIG_NO_CONVERSION 11 12 #include "csrucode.h" 13 #include "csmatch.h" 14 15 U_NAMESPACE_BEGIN 16 17 CharsetRecog_Unicode::~CharsetRecog_Unicode() 18 { 19 // nothing to do 20 } 21 22 CharsetRecog_UTF_16_BE::~CharsetRecog_UTF_16_BE() 23 { 24 // nothing to do 25 } 26 27 const char *CharsetRecog_UTF_16_BE::getName() const 28 { 29 return "UTF-16BE"; 30 } 31 32 UBool CharsetRecog_UTF_16_BE::match(InputText* textIn, CharsetMatch *results) const 33 { 34 const uint8_t *input = textIn->fRawInput; 35 int32_t confidence = 0; 36 37 if (input[0] == 0xFE && input[1] == 0xFF) { 38 confidence = 100; 39 } 40 41 // TODO: Do some statastics to check for unsigned UTF-16BE 42 results->set(textIn, this, confidence); 43 return (confidence > 0); 44 } 45 46 CharsetRecog_UTF_16_LE::~CharsetRecog_UTF_16_LE() 47 { 48 // nothing to do 49 } 50 51 const char *CharsetRecog_UTF_16_LE::getName() const 52 { 53 return "UTF-16LE"; 54 } 55 56 UBool CharsetRecog_UTF_16_LE::match(InputText* textIn, CharsetMatch *results) const 57 { 58 const uint8_t *input = textIn->fRawInput; 59 int32_t confidence = 0; 60 61 if (input[0] == 0xFF && input[1] == 0xFE && (input[2] != 0x00 || input[3] != 0x00)) { 62 confidence = 100; 63 } 64 65 // TODO: Do some statastics to check for unsigned UTF-16LE 66 results->set(textIn, this, confidence); 67 return (confidence > 0); 68 } 69 70 CharsetRecog_UTF_32::~CharsetRecog_UTF_32() 71 { 72 // nothing to do 73 } 74 75 UBool CharsetRecog_UTF_32::match(InputText* textIn, CharsetMatch *results) const 76 { 77 const uint8_t *input = textIn->fRawInput; 78 int32_t limit = (textIn->fRawLength / 4) * 4; 79 int32_t numValid = 0; 80 int32_t numInvalid = 0; 81 bool hasBOM = FALSE; 82 int32_t confidence = 0; 83 84 if (getChar(input, 0) == 0x0000FEFFUL) { 85 hasBOM = TRUE; 86 } 87 88 for(int32_t i = 0; i < limit; i += 4) { 89 int32_t ch = getChar(input, i); 90 91 if (ch < 0 || ch >= 0x10FFFF || (ch >= 0xD800 && ch <= 0xDFFF)) { 92 numInvalid += 1; 93 } else { 94 numValid += 1; 95 } 96 } 97 98 99 // Cook up some sort of confidence score, based on presense of a BOM 100 // and the existence of valid and/or invalid multi-byte sequences. 101 if (hasBOM && numInvalid==0) { 102 confidence = 100; 103 } else if (hasBOM && numValid > numInvalid*10) { 104 confidence = 80; 105 } else if (numValid > 3 && numInvalid == 0) { 106 confidence = 100; 107 } else if (numValid > 0 && numInvalid == 0) { 108 confidence = 80; 109 } else if (numValid > numInvalid*10) { 110 // Probably corruput UTF-32BE data. Valid sequences aren't likely by chance. 111 confidence = 25; 112 } 113 114 results->set(textIn, this, confidence); 115 return (confidence > 0); 116 } 117 118 CharsetRecog_UTF_32_BE::~CharsetRecog_UTF_32_BE() 119 { 120 // nothing to do 121 } 122 123 const char *CharsetRecog_UTF_32_BE::getName() const 124 { 125 return "UTF-32BE"; 126 } 127 128 int32_t CharsetRecog_UTF_32_BE::getChar(const uint8_t *input, int32_t index) const 129 { 130 return input[index + 0] << 24 | input[index + 1] << 16 | 131 input[index + 2] << 8 | input[index + 3]; 132 } 133 134 CharsetRecog_UTF_32_LE::~CharsetRecog_UTF_32_LE() 135 { 136 // nothing to do 137 } 138 139 const char *CharsetRecog_UTF_32_LE::getName() const 140 { 141 return "UTF-32LE"; 142 } 143 144 int32_t CharsetRecog_UTF_32_LE::getChar(const uint8_t *input, int32_t index) const 145 { 146 return input[index + 3] << 24 | input[index + 2] << 16 | 147 input[index + 1] << 8 | input[index + 0]; 148 } 149 150 U_NAMESPACE_END 151 #endif 152 153
