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