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 *strstr16(const char16_t*, const char16_t*); 31 32 // Version of comparison that supports embedded NULs. 33 // This is different than strncmp() because we don't stop 34 // at a nul character and consider the strings to be different 35 // if the lengths are different (thus we need to supply the 36 // lengths of both strings). This can also be used when 37 // your string is not nul-terminated as it will have the 38 // equivalent result as strcmp16 (unlike strncmp16). 39 int strzcmp16(const char16_t *s1, size_t n1, const char16_t *s2, size_t n2); 40 41 /** 42 * Measure the length of a UTF-32 string in UTF-8. If the string is invalid 43 * such as containing a surrogate character, -1 will be returned. 44 */ 45 ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len); 46 47 /** 48 * Stores a UTF-8 string converted from "src" in "dst", if "dst_length" is not 49 * large enough to store the string, the part of the "src" string is stored 50 * into "dst" as much as possible. See the examples for more detail. 51 * Returns the size actually used for storing the string. 52 * dst" is not nul-terminated when dst_len is fully used (like strncpy). 53 * 54 * \code 55 * Example 1 56 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 57 * "src_len" == 2 58 * "dst_len" >= 7 59 * -> 60 * Returned value == 6 61 * "dst" becomes \xE3\x81\x82\xE3\x81\x84\0 62 * (note that "dst" is nul-terminated) 63 * 64 * Example 2 65 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 66 * "src_len" == 2 67 * "dst_len" == 5 68 * -> 69 * Returned value == 3 70 * "dst" becomes \xE3\x81\x82\0 71 * (note that "dst" is nul-terminated, but \u3044 is not stored in "dst" 72 * since "dst" does not have enough size to store the character) 73 * 74 * Example 3 75 * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84) 76 * "src_len" == 2 77 * "dst_len" == 6 78 * -> 79 * Returned value == 6 80 * "dst" becomes \xE3\x81\x82\xE3\x81\x84 81 * (note that "dst" is NOT nul-terminated, like strncpy) 82 * \endcode 83 */ 84 void utf32_to_utf8(const char32_t* src, size_t src_len, char* dst, size_t dst_len); 85 86 /** 87 * Returns the unicode value at "index". 88 * Returns -1 when the index is invalid (equals to or more than "src_len"). 89 * If returned value is positive, it is able to be converted to char32_t, which 90 * is unsigned. Then, if "next_index" is not NULL, the next index to be used is 91 * stored in "next_index". "next_index" can be NULL. 92 */ 93 int32_t utf32_from_utf8_at(const char *src, size_t src_len, size_t index, size_t *next_index); 94 95 96 /** 97 * Returns the UTF-8 length of UTF-16 string "src". 98 */ 99 ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len); 100 101 /** 102 * Converts a UTF-16 string to UTF-8. The destination buffer must be large 103 * enough to fit the UTF-16 as measured by utf16_to_utf8_length with an added 104 * NUL terminator. 105 */ 106 void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst, size_t dst_len); 107 108 /** 109 * Returns the UTF-16 length of UTF-8 string "src". Returns -1 in case 110 * it's invalid utf8. No buffer over-read occurs because of bound checks. Using overreadIsFatal you 111 * can ask to log a message and fail in case the invalid utf8 could have caused an override if no 112 * bound checks were used (otherwise -1 is returned). 113 */ 114 ssize_t utf8_to_utf16_length(const uint8_t* src, size_t srcLen, bool overreadIsFatal = false); 115 116 /** 117 * Convert UTF-8 to UTF-16 including surrogate pairs. 118 * Returns a pointer to the end of the string (where a NUL terminator might go 119 * if you wanted to add one). At most dstLen characters are written; it won't emit half a surrogate 120 * pair. If dstLen == 0 nothing is written and dst is returned. If dstLen > SSIZE_MAX it aborts 121 * (this being probably a negative number returned as an error and casted to unsigned). 122 */ 123 char16_t* utf8_to_utf16_no_null_terminator( 124 const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen); 125 126 /** 127 * Convert UTF-8 to UTF-16 including surrogate pairs. At most dstLen - 1 128 * characters are written; it won't emit half a surrogate pair; and a NUL terminator is appended 129 * after. dstLen - 1 can be measured beforehand using utf8_to_utf16_length. Aborts if dstLen == 0 130 * (at least one character is needed for the NUL terminator) or dstLen > SSIZE_MAX (the latter 131 * case being likely a negative number returned as an error and casted to unsigned) . Returns a 132 * pointer to the NUL terminator. 133 */ 134 char16_t *utf8_to_utf16( 135 const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen); 136 137 } 138 139 #endif 140