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#include "jansson_private.h"
#include "strbuffer.h"
#include <assert.h>
#include <errno.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
/* need jansson_private_config.h to get the correct snprintf */
#ifdef HAVE_CONFIG_H
#include <jansson_private_config.h>
#endif
/*
- This code assumes that the decimal separator is exactly one
character.
- If setlocale() is called by another thread between the call to
get_decimal_point() and the call to sprintf() or strtod(), the
result may be wrong. setlocale() is not thread-safe and should
not be used this way. Multi-threaded programs should use
uselocale() instead.
*/
static char get_decimal_point() {
char buf[3];
sprintf(buf, "%#.0f", 1.0); // "1." in the current locale
return buf[1];
}
static void to_locale(strbuffer_t *strbuffer) {
char point;
char *pos;
point = get_decimal_point();
if (point == '.') {
/* No conversion needed */
return;
}
pos = strchr(strbuffer->value, '.');
if (pos)
*pos = point;
}
static void from_locale(char *buffer) {
char point;
char *pos;
point = get_decimal_point();
if (point == '.') {
/* No conversion needed */
return;
}
pos = strchr(buffer, point);
if (pos)
*pos = '.';
}
int jsonp_strtod(strbuffer_t *strbuffer, double *out) {
double value;
char *end;
to_locale(strbuffer);
errno = 0;
value = strtod(strbuffer->value, &end);
assert(end == strbuffer->value + strbuffer->length);
if ((value == HUGE_VAL || value == -HUGE_VAL) && errno == ERANGE) {
/* Overflow */
return -1;
}
*out = value;
return 0;
}
int jsonp_dtostr(char *buffer, size_t size, double value, int precision) {
int ret;
char *start, *end;
size_t length;
if (precision == 0)
precision = 17;
ret = snprintf(buffer, size, "%.*g", precision, value);
if (ret < 0)
return -1;
length = (size_t)ret;
if (length >= size)
return -1;
from_locale(buffer);
/* Make sure there's a dot or 'e' in the output. Otherwise
a real is converted to an integer when decoding */
if (strchr(buffer, '.') == NULL && strchr(buffer, 'e') == NULL) {
if (length + 3 >= size) {
/* No space to append ".0" */
return -1;
}
buffer[length] = '.';
buffer[length + 1] = '0';
buffer[length + 2] = '\0';
length += 2;
}
/* Remove leading '+' from positive exponent. Also remove leading
zeros from exponents (added by some printf() implementations) */
start = strchr(buffer, 'e');
if (start) {
start++;
end = start + 1;
if (*start == '-')
start++;
while (*end == '0')
end++;
if (end != start) {
memmove(start, end, length - (size_t)(end - buffer));
length -= (size_t)(end - start);
}
}
return (int)length;
}
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