1 /* 2 * Copyright (C) 2005 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_UNICODE_H 18 #define ANDROID_UNICODE_H 19 20 #include <sys/types.h> 21 #include <stdint.h> 22 23 extern "C" { 24 25 // Definitions exist in C++11 26 #if defined __cplusplus && __cplusplus < 201103L 27 typedef uint32_t char32_t; 28 typedef uint16_t char16_t; 29 #endif 30 31 // Standard string functions on char16_t strings. 32 int strcmp16(const char16_t *, const char16_t *); 33 int strncmp16(const char16_t *s1, const char16_t *s2, size_t n); 34 size_t strlen16(const char16_t *); 35 size_t strnlen16(const char16_t *, size_t); 36 char16_t *strcpy16(char16_t *, const char16_t *); 37 char16_t *strncpy16(char16_t *, const char16_t *, size_t); 38 39 // Version of comparison that supports embedded nulls. 40 // This is different than strncmp() because we don't stop 41 // at a nul character and consider the strings to be different 42 // if the lengths are different (thus we need to supply the 43 // lengths of both strings). This can also be used when 44 // your string is not nul-terminated as it will have the 45 // equivalent result as strcmp16 (unlike strncmp16). 46 int strzcmp16(const char16_t *s1, size_t n1, const char16_t *s2, size_t n2); 47 48 // Version of strzcmp16 for comparing strings in different endianness. 49 int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2); 50 51 // Standard string functions on char32_t strings. 52 size_t strlen32(const char32_t *); 53 size_t strnlen32(const char32_t *, size_t); 54 55 /** 56 * Measure the length of a UTF-32 string in UTF-8. If the string is invalid 57 * such as containing a surrogate character, -1 will be returned. 58 */ 59 ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len); 60 61 /** 62 * Stores a UTF-8 string converted from "src" in "dst", if "dst_length" is not 63 * large enough to store the string, the part of the "src" string is stored 64 * into "dst" as much as possible. See the examples for more detail. 65 * Returns the size actually used for storing the string. 66 * dst" is not null-terminated when dst_len is fully used (like strncpy). 67 * 68 * Example 1 69 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 70 * "src_len" == 2 71 * "dst_len" >= 7 72 * -> 73 * Returned value == 6 74 * "dst" becomes \xE3\x81\x82\xE3\x81\x84\0 75 * (note that "dst" is null-terminated) 76 * 77 * Example 2 78 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 79 * "src_len" == 2 80 * "dst_len" == 5 81 * -> 82 * Returned value == 3 83 * "dst" becomes \xE3\x81\x82\0 84 * (note that "dst" is null-terminated, but \u3044 is not stored in "dst" 85 * since "dst" does not have enough size to store the character) 86 * 87 * Example 3 88 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 89 * "src_len" == 2 90 * "dst_len" == 6 91 * -> 92 * Returned value == 6 93 * "dst" becomes \xE3\x81\x82\xE3\x81\x84 94 * (note that "dst" is NOT null-terminated, like strncpy) 95 */ 96 void utf32_to_utf8(const char32_t* src, size_t src_len, char* dst); 97 98 /** 99 * Returns the unicode value at "index". 100 * Returns -1 when the index is invalid (equals to or more than "src_len"). 101 * If returned value is positive, it is able to be converted to char32_t, which 102 * is unsigned. Then, if "next_index" is not NULL, the next index to be used is 103 * stored in "next_index". "next_index" can be NULL. 104 */ 105 int32_t utf32_from_utf8_at(const char *src, size_t src_len, size_t index, size_t *next_index); 106 107 108 /** 109 * Returns the UTF-8 length of UTF-16 string "src". 110 */ 111 ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len); 112 113 /** 114 * Converts a UTF-16 string to UTF-8. The destination buffer must be large 115 * enough to fit the UTF-16 as measured by utf16_to_utf8_length with an added 116 * NULL terminator. 117 */ 118 void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst); 119 120 /** 121 * Returns the length of "src" when "src" is valid UTF-8 string. 122 * Returns 0 if src is NULL or 0-length string. Returns -1 when the source 123 * is an invalid string. 124 * 125 * This function should be used to determine whether "src" is valid UTF-8 126 * characters with valid unicode codepoints. "src" must be null-terminated. 127 * 128 * If you are going to use other utf8_to_... functions defined in this header 129 * with string which may not be valid UTF-8 with valid codepoint (form 0 to 130 * 0x10FFFF), you should use this function before calling others, since the 131 * other functions do not check whether the string is valid UTF-8 or not. 132 * 133 * If you do not care whether "src" is valid UTF-8 or not, you should use 134 * strlen() as usual, which should be much faster. 135 */ 136 ssize_t utf8_length(const char *src); 137 138 /** 139 * Measure the length of a UTF-32 string. 140 */ 141 size_t utf8_to_utf32_length(const char *src, size_t src_len); 142 143 /** 144 * Stores a UTF-32 string converted from "src" in "dst". "dst" must be large 145 * enough to store the entire converted string as measured by 146 * utf8_to_utf32_length plus space for a NULL terminator. 147 */ 148 void utf8_to_utf32(const char* src, size_t src_len, char32_t* dst); 149 150 /** 151 * Returns the UTF-16 length of UTF-8 string "src". 152 */ 153 ssize_t utf8_to_utf16_length(const uint8_t* src, size_t srcLen); 154 155 /** 156 * Convert UTF-8 to UTF-16 including surrogate pairs. 157 * Returns a pointer to the end of the string (where a null terminator might go 158 * if you wanted to add one). 159 */ 160 char16_t* utf8_to_utf16_no_null_terminator(const uint8_t* src, size_t srcLen, char16_t* dst); 161 162 /** 163 * Convert UTF-8 to UTF-16 including surrogate pairs. The destination buffer 164 * must be large enough to hold the result as measured by utf8_to_utf16_length 165 * plus an added NULL terminator. 166 */ 167 void utf8_to_utf16(const uint8_t* src, size_t srcLen, char16_t* dst); 168 169 /** 170 * Like utf8_to_utf16_no_null_terminator, but you can supply a maximum length of the 171 * decoded string. The decoded string will fill up to that length; if it is longer 172 * the returned pointer will be to the character after dstLen. 173 */ 174 char16_t* utf8_to_utf16_n(const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen); 175 176 } 177 178 #endif 179
