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;
#if JSON_HAVE_LOCALECONV
from_locale(buffer);
#endif
/* 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;
}
int os_dtostr(double value, char *dst, size_t size)
{
int ret;
char *start, *end;
size_t length;
ret = snprintf(dst, size, "%.17g", value);
if(ret < 0)
return -1;
length = (size_t)ret;
if(length >= size)
return -1;
from_locale(dst);
/* Make sure there's a dot or 'e' in the output. Otherwise
a real is converted to an integer when decoding */
if(strchr(dst, '.') == NULL && strchr(dst, 'e') == NULL) {
if(length + 3 >= size) {
/* No space to append ".0" */
return -1;
}
dst[length] = '.';
dst[length + 1] = '0';
dst[length + 2] = '\0';
length += 2;
}
/* Remove leading '+' from positive exponent. Also remove leading
zeros from exponents (added by some printf() implementations) */
start = strchr(dst, 'e');
if(start) {
start++;
end = start + 1;
if(*start == '-')
start++;
while(*end == '0')
end++;
if(end != start) {
memmove(start, end, length - (size_t)(end - dst));
length -= (size_t)(end - start);
}
}
return (int)length;
}
