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 /*

  * Copyright (C) 2005 The Android Open Source Project

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 #ifndef ANDROID_UNICODE_H

 #define ANDROID_UNICODE_H

 #include <sys/types.h>

 #include <stdint.h>

 extern "C" {

 #if !defined(__cplusplus) || __cplusplus == 199711L // C or C++98

 typedef uint32_t char32_t;

 typedef uint16_t char16_t;

 #endif

 // Standard string functions on char16_t strings.

 int strcmp16(const char16_t *, const char16_t *);

 int strncmp16(const char16_t *s1, const char16_t *s2, size_t n);

 size_t strlen16(const char16_t *);

 size_t strnlen16(const char16_t *, size_t);

 char16_t *strcpy16(char16_t *, const char16_t *);

 char16_t *strncpy16(char16_t *, const char16_t *, size_t);

 // Version of comparison that supports embedded nulls.

 // This is different than strncmp() because we don't stop

 // at a nul character and consider the strings to be different

 // if the lengths are different (thus we need to supply the

 // lengths of both strings).  This can also be used when

 // your string is not nul-terminated as it will have the

 // equivalent result as strcmp16 (unlike strncmp16).

 int strzcmp16(const char16_t *s1, size_t n1, const char16_t *s2, size_t n2);

 // Version of strzcmp16 for comparing strings in different endianness.

 int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2);

 // Standard string functions on char32_t strings.

 size_t strlen32(const char32_t *);

 size_t strnlen32(const char32_t *, size_t);

 /**

  * Measure the length of a UTF-32 string in UTF-8. If the string is invalid

  * such as containing a surrogate character, -1 will be returned.

  */

 ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len);

 /**

  * Stores a UTF-8 string converted from "src" in "dst", if "dst_length" is not

  * large enough to store the string, the part of the "src" string is stored

  * into "dst" as much as possible. See the examples for more detail.

  * Returns the size actually used for storing the string.

  * dst" is not null-terminated when dst_len is fully used (like strncpy).

  *

  * Example 1

  * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84)

  * "src_len" == 2

  * "dst_len" >= 7

  * ->

  * Returned value == 6

  * "dst" becomes \xE3\x81\x82\xE3\x81\x84\0

  * (note that "dst" is null-terminated)

  *

  * Example 2

  * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84)

  * "src_len" == 2

  * "dst_len" == 5

  * ->

  * Returned value == 3

  * "dst" becomes \xE3\x81\x82\0

  * (note that "dst" is null-terminated, but \u3044 is not stored in "dst"

  * since "dst" does not have enough size to store the character)

  *

  * Example 3

  * "src" == \u3042\u3044 (\xE3\x81\x82\xE3\x81\x84)

  * "src_len" == 2

  * "dst_len" == 6

  * ->

  * Returned value == 6

  * "dst" becomes \xE3\x81\x82\xE3\x81\x84

  * (note that "dst" is NOT null-terminated, like strncpy)

  */

 void utf32_to_utf8(const char32_t* src, size_t src_len, char* dst);

 /**

  * Returns the unicode value at "index".

  * Returns -1 when the index is invalid (equals to or more than "src_len").

  * If returned value is positive, it is able to be converted to char32_t, which

  * is unsigned. Then, if "next_index" is not NULL, the next index to be used is

  * stored in "next_index". "next_index" can be NULL.

  */

 int32_t utf32_from_utf8_at(const char *src, size_t src_len, size_t index, size_t *next_index);

 /**

  * Returns the UTF-8 length of UTF-16 string "src".

  */

 ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len);

 /**

  * Converts a UTF-16 string to UTF-8. The destination buffer must be large

  * enough to fit the UTF-16 as measured by utf16_to_utf8_length with an added

  * NULL terminator.

  */

 void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst);

 /**

  * Returns the length of "src" when "src" is valid UTF-8 string.

  * Returns 0 if src is NULL or 0-length string. Returns -1 when the source

  * is an invalid string.

  *

  * This function should be used to determine whether "src" is valid UTF-8

  * characters with valid unicode codepoints. "src" must be null-terminated.

  *

  * If you are going to use other utf8_to_... functions defined in this header

  * with string which may not be valid UTF-8 with valid codepoint (form 0 to

  * 0x10FFFF), you should use this function before calling others, since the

  * other functions do not check whether the string is valid UTF-8 or not.

  *

  * If you do not care whether "src" is valid UTF-8 or not, you should use

  * strlen() as usual, which should be much faster.

  */

 ssize_t utf8_length(const char *src);

 /**

  * Measure the length of a UTF-32 string.

  */

 size_t utf8_to_utf32_length(const char *src, size_t src_len);

 /**

  * Stores a UTF-32 string converted from "src" in "dst". "dst" must be large

  * enough to store the entire converted string as measured by

  * utf8_to_utf32_length plus space for a NULL terminator.

  */

 void utf8_to_utf32(const char* src, size_t src_len, char32_t* dst);

 /**

  * Returns the UTF-16 length of UTF-8 string "src".

  */

 ssize_t utf8_to_utf16_length(const uint8_t* src, size_t srcLen);

 /**

  * Convert UTF-8 to UTF-16 including surrogate pairs.

  * Returns a pointer to the end of the string (where a null terminator might go

  * if you wanted to add one).

  */

 char16_t* utf8_to_utf16_no_null_terminator(const uint8_t* src, size_t srcLen, char16_t* dst);

 /**

  * Convert UTF-8 to UTF-16 including surrogate pairs. The destination buffer

  * must be large enough to hold the result as measured by utf8_to_utf16_length

  * plus an added NULL terminator.

  */

 void utf8_to_utf16(const uint8_t* src, size_t srcLen, char16_t* dst);

 }

 #endif