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 // Standard string functions on char16_t strings. 26 int strcmp16(const char16_t *, const char16_t *); 27 int strncmp16(const char16_t *s1, const char16_t *s2, size_t n); 28 size_t strlen16(const char16_t *); 29 size_t strnlen16(const char16_t *, size_t); 30 char16_t *strcpy16(char16_t *, const char16_t *); 31 char16_t *strncpy16(char16_t *, const char16_t *, size_t); 32 char16_t *strstr16(const char16_t*, const char16_t*); 33 34 // Version of comparison that supports embedded NULs. 35 // This is different than strncmp() because we don't stop 36 // at a nul character and consider the strings to be different 37 // if the lengths are different (thus we need to supply the 38 // lengths of both strings). This can also be used when 39 // your string is not nul-terminated as it will have the 40 // equivalent result as strcmp16 (unlike strncmp16). 41 int strzcmp16(const char16_t *s1, size_t n1, const char16_t *s2, size_t n2); 42 43 // Version of strzcmp16 for comparing strings in different endianness. 44 int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2); 45 46 // Standard string functions on char32_t strings. 47 size_t strlen32(const char32_t *); 48 size_t strnlen32(const char32_t *, size_t); 49 50 /** 51 * Measure the length of a UTF-32 string in UTF-8. If the string is invalid 52 * such as containing a surrogate character, -1 will be returned. 53 */ 54 ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len); 55 56 /** 57 * Stores a UTF-8 string converted from "src" in "dst", if "dst_length" is not 58 * large enough to store the string, the part of the "src" string is stored 59 * into "dst" as much as possible. See the examples for more detail. 60 * Returns the size actually used for storing the string. 61 * dst" is not nul-terminated when dst_len is fully used (like strncpy). 62 * 63 * \code 64 * Example 1 65 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 66 * "src_len" == 2 67 * "dst_len" >= 7 68 * -> 69 * Returned value == 6 70 * "dst" becomes \xE3\x81\x82\xE3\x81\x84\0 71 * (note that "dst" is nul-terminated) 72 * 73 * Example 2 74 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 75 * "src_len" == 2 76 * "dst_len" == 5 77 * -> 78 * Returned value == 3 79 * "dst" becomes \xE3\x81\x82\0 80 * (note that "dst" is nul-terminated, but \u3044 is not stored in "dst" 81 * since "dst" does not have enough size to store the character) 82 * 83 * Example 3 84 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 85 * "src_len" == 2 86 * "dst_len" == 6 87 * -> 88 * Returned value == 6 89 * "dst" becomes \xE3\x81\x82\xE3\x81\x84 90 * (note that "dst" is NOT nul-terminated, like strncpy) 91 * \endcode 92 */ 93 void utf32_to_utf8(const char32_t* src, size_t src_len, char* dst, size_t dst_len); 94 95 /** 96 * Returns the unicode value at "index". 97 * Returns -1 when the index is invalid (equals to or more than "src_len"). 98 * If returned value is positive, it is able to be converted to char32_t, which 99 * is unsigned. Then, if "next_index" is not NULL, the next index to be used is 100 * stored in "next_index". "next_index" can be NULL. 101 */ 102 int32_t utf32_from_utf8_at(const char *src, size_t src_len, size_t index, size_t *next_index); 103 104 105 /** 106 * Returns the UTF-8 length of UTF-16 string "src". 107 */ 108 ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len); 109 110 /** 111 * Converts a UTF-16 string to UTF-8. The destination buffer must be large 112 * enough to fit the UTF-16 as measured by utf16_to_utf8_length with an added 113 * NUL terminator. 114 */ 115 void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst, size_t dst_len); 116 117 /** 118 * Returns the length of "src" when "src" is valid UTF-8 string. 119 * Returns 0 if src is NULL or 0-length string. Returns -1 when the source 120 * is an invalid string. 121 * 122 * This function should be used to determine whether "src" is valid UTF-8 123 * characters with valid unicode codepoints. "src" must be nul-terminated. 124 * 125 * If you are going to use other utf8_to_... functions defined in this header 126 * with string which may not be valid UTF-8 with valid codepoint (form 0 to 127 * 0x10FFFF), you should use this function before calling others, since the 128 * other functions do not check whether the string is valid UTF-8 or not. 129 * 130 * If you do not care whether "src" is valid UTF-8 or not, you should use 131 * strlen() as usual, which should be much faster. 132 */ 133 ssize_t utf8_length(const char *src); 134 135 /** 136 * Measure the length of a UTF-32 string. 137 */ 138 size_t utf8_to_utf32_length(const char *src, size_t src_len); 139 140 /** 141 * Stores a UTF-32 string converted from "src" in "dst". "dst" must be large 142 * enough to store the entire converted string as measured by 143 * utf8_to_utf32_length plus space for a NUL terminator. 144 */ 145 void utf8_to_utf32(const char* src, size_t src_len, char32_t* dst); 146 147 /** 148 * Returns the UTF-16 length of UTF-8 string "src". Returns -1 in case 149 * it's invalid utf8. No buffer over-read occurs because of bound checks. Using overreadIsFatal you 150 * can ask to log a message and fail in case the invalid utf8 could have caused an override if no 151 * bound checks were used (otherwise -1 is returned). 152 */ 153 ssize_t utf8_to_utf16_length(const uint8_t* src, size_t srcLen, bool overreadIsFatal = false); 154 155 /** 156 * Convert UTF-8 to UTF-16 including surrogate pairs. 157 * Returns a pointer to the end of the string (where a NUL terminator might go 158 * if you wanted to add one). At most dstLen characters are written; it won't emit half a surrogate 159 * pair. If dstLen == 0 nothing is written and dst is returned. If dstLen > SSIZE_MAX it aborts 160 * (this being probably a negative number returned as an error and casted to unsigned). 161 */ 162 char16_t* utf8_to_utf16_no_null_terminator( 163 const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen); 164 165 /** 166 * Convert UTF-8 to UTF-16 including surrogate pairs. At most dstLen - 1 167 * characters are written; it won't emit half a surrogate pair; and a NUL terminator is appended 168 * after. dstLen - 1 can be measured beforehand using utf8_to_utf16_length. Aborts if dstLen == 0 169 * (at least one character is needed for the NUL terminator) or dstLen > SSIZE_MAX (the latter 170 * case being likely a negative number returned as an error and casted to unsigned) . Returns a 171 * pointer to the NUL terminator. 172 */ 173 char16_t *utf8_to_utf16( 174 const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen); 175 176 } 177 178 #endif 179
