dtssUtf8Encode2 Function

File

File: dtsearch.h

Syntax

C++

ptrdiff_t DLLFUNC dtssUtf8Encode2(char * dest, ptrdiff_t cchDest, const wchar_t * toEncode, ptrdiff_t cchSource, __int64 * cchNeeded);

Group

Functions

Parameters

Parameters	Description
char * dest	Buffer to receive UTF-8 text
ptrdiff_t cchDest	Size of dest buffer in bytes
ptrdiff_t cchSource	Number of unicode characters to convert
__int64 * cchNeeded	Pointer to 64-bit interer to hold the number of characters needed to store the encoded result, if the buffer provided was too small.
source	Unicode (UTF-16) text to convert

Returns

Number of characters in the conversion output, excluding the terminating null.

Description

Convert Unicode to UTF-8

Remarks

If the buffer provided in dest is insufficient to store the conversion result, the required buffer size will be provided in cchNeeded.

If the buffer provided was large enough to store the result, cchNeeded will not be changed.

To use this API efficiently, callers should initialize cchNeeded to zero, provide an output buffer that is large enough to handle the the most common cases, and then check cchNeeded after the conversion is done to determine whether a larger buffer is needed. This avoids the need to call the API twice in the most common cases.

Conversion to UTF-8 can generate output with up to 5 times the number of characters as the input, so even with a 32-bit value for cchSource, the value in cchNeeded may be too large to fit in a 32-bit integer.