/*
* Copyright (c) 2006 Josef Cejka
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup generic
* @{
*/
/** @file
*/
#include <print.h>
#include <printf/printf_core.h>
#include <string.h>
#include <memstr.h>
typedef struct {
size_t size; /* Total size of the buffer (in bytes) */
size_t len; /* Number of already used bytes */
char *dst; /* Destination */
} vsnprintf_data_t;
/** Write UTF-8 string to given buffer.
*
* Write at most data->size plain characters including trailing zero.
* According to C99, snprintf() has to return number of characters that
* would have been written if enough space had been available. Hence
* the return value is not the number of actually printed characters
* but size of the input string.
*
* @param str Source UTF-8 string to print.
* @param size Number of plain characters in str.
* @param data Structure describing destination string, counter
* of used space and total string size.
*
* @return Number of UTF-8 characters to print (not characters actually
* printed).
*
*/
static int vsnprintf_write_utf8(const char *str, size_t size, vsnprintf_data_t *data)
{
size_t left = data->size - data->len;
if (left == 0)
return ((int) size);
if (left == 1) {
/* We have only one free byte left in buffer
* -> store trailing zero
*/
data->dst[data->size - 1] = 0;
data->len = data->size;
return ((int) size);
}
if (left <= size) {
/* We have not enought space for whole string
* with the trailing zero => print only a part
* of string
*/
index_t index = 0;
while (index < size) {
wchar_t uc = utf8_decode(str, &index, size - 1);
if (!utf8_encode(uc, data->dst, &data->len, data->size - 2))
break;
data->len++;
index++;
}
/* Put trailing zero at end, but not count it
* into data->len so it could be rewritten next time
*/
data->dst[data->len] = 0;
return ((int) size);
}
/* Buffer is big enought to print the whole string */
memcpy((void *)(data
->dst
+ data
->len
), (void *) str
, size
); data->len += size;
/* Put trailing zero at end, but not count it
* into data->len so it could be rewritten next time
*/
data->dst[data->len] = 0;
return ((int) size);
}
/** Write UTF-32 string to given buffer.
*
* Write at most data->size plain characters including trailing zero.
* According to C99, snprintf() has to return number of characters that
* would have been written if enough space had been available. Hence
* the return value is not the number of actually printed characters
* but size of the input string.
*
* @param str Source UTF-32 string to print.
* @param size Number of bytes in str.
* @param data Structure describing destination string, counter
* of used space and total string size.
*
* @return Number of UTF-8 characters to print (not characters actually
* printed).
*
*/
static int vsnprintf_write_utf32(const wchar_t *str, size_t size, vsnprintf_data_t *data)
{
index_t index = 0;
while (index < (size / sizeof(wchar_t))) {
size_t left = data->size - data->len;
if (left == 0)
return ((int) size);
if (left == 1) {
/* We have only one free byte left in buffer
* -> store trailing zero
*/
data->dst[data->size - 1] = 0;
data->len = data->size;
return ((int) size);
}
if (!utf8_encode(str[index], data->dst, &data->len, data->size - 2))
break;
data->len++;
index++;
}
/* Put trailing zero at end, but not count it
* into data->len so it could be rewritten next time
*/
data->dst[data->len] = 0;
return ((int) size);
}
int vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
{
vsnprintf_data_t data = {
size,
0,
str
};
printf_spec_t ps = {
(int(*) (const char *, size_t, void *)) vsnprintf_write_utf8,
(int(*) (const wchar_t *, size_t, void *)) vsnprintf_write_utf32,
&data
};
/* Print 0 at end of string - fix the case that nothing will be printed */
if (size > 0)
str[0] = 0;
/* vsnprintf_write ensures that str will be terminated by zero. */
return printf_core(fmt, &ps, ap);
}
/** @}
*/