/** dropt_ssclear
*
* Clears and re-initializes a dropt_stringstream.
*
* PARAMETERS:
* IN/OUT ss : The dropt_stringstream
*/
void
dropt_ssclear(dropt_stringstream* ss)
{
assert(ss != NULL);
ss->string[0] = DROPT_TEXT_LITERAL('\0');
ss->used = 0;
dropt_ssresize(ss, default_stringstream_buffer_size);
}
/** dropt_ssfinalize
*
* Finalizes a dropt_stringstream; returns the contained string and
* destroys the dropt_stringstream.
*
* PARAMETERS:
* IN/OUT ss : The dropt_stringstream.
*
* RETURNS:
* The dropt_stringstream's string, which is always NUL-terminated.
* Note that the caller assumes ownership of the returned string and
* is responsible for calling free() on it when no longer needed.
*/
dropt_char*
dropt_ssfinalize(dropt_stringstream* ss)
{
dropt_char* s;
assert(ss != NULL);
/* Shrink to fit. */
dropt_ssresize(ss, 0);
s = ss->string;
ss->string = NULL;
dropt_ssclose(ss);
return s;
}
/** dropt_vssprintf
*
* Appends a formatted string with vprintf semantics to a
* dropt_stringstream.
*
* PARAMETERS:
* IN/OUT ss : The dropt_stringstream.
* IN format : printf-style format specifier. Must not be NULL.
* IN args : Arguments to insert into the formatted string.
*
* RETURNS:
* The number of characters written to the dropt_stringstream,
* excluding the NUL-terminator.
* Returns a negative value on error.
*/
int
dropt_vssprintf(dropt_stringstream * ss, const dropt_char * format, va_list args)
{
int n;
va_list argsCopy;
assert(ss != NULL);
assert(format != NULL);
va_copy(argsCopy, args);
n = dropt_vsnprintf(NULL, 0, format, argsCopy);
va_end(argsCopy);
if (n > 0) {
size_t available = dropt_ssgetfreespace(ss);
if ((unsigned int) n >= available) {
/* It's possible that newSize < ss->maxSize if
* GROWN_STRINGSTREAM_BUFFER_SIZE overflows, but it should be
* safe since we'll recompute the available space.
*/
size_t newSize = GROWN_STRINGSTREAM_BUFFER_SIZE(ss->maxSize, n);
dropt_ssresize(ss, newSize);
available = dropt_ssgetfreespace(ss);
}
assert(available > 0); /* Space always is reserved for NUL. */
/* snprintf's family of functions return the number of characters
* that would be output with a sufficiently large buffer, excluding
* NUL.
*/
n = dropt_vsnprintf(ss->string + ss->used, available, format, args);
/* We couldn't allocate enough space. */
if ((unsigned int) n >= available) {
n = -1;
}
if (n > 0) {
ss->used += n;
}
}
return n;
}
