Function string_filter

src/jrd/filters.cpp:1298–1357

static ISC_STATUS string_filter(USHORT action, BlobControl* control)
{
/**************************************
 *
 *	s t r i n g _ f i l t e r
 *
 **************************************
 *
 * Functional description
 *	Handle stuff for batched string filters.  This is used by filter_blr
 *	and filter_acl.
 *
 **************************************/
	filter_tmp* string;

	switch (action)
	{
	case isc_blob_filter_close:
		while (string = (filter_tmp*) control->ctl_data[0])
		{
			control->ctl_data[0] = (IPTR) string->tmp_next;
			gds__free(string);
		}
		return FB_SUCCESS;

	case isc_blob_filter_get_segment:
	{
		if (!(string = (filter_tmp*) control->ctl_data[1]))
			return isc_segstr_eof;

		USHORT length = string->tmp_length - control->ctl_data[2];
		const bool outOfBuffer = (length > control->ctl_buffer_length);

		if (outOfBuffer)
			length = control->ctl_buffer_length;
		memcpy(control->ctl_buffer, string->tmp_string + (USHORT) control->ctl_data[2], length);
		control->ctl_data[2] += length;
		if (control->ctl_data[2] == string->tmp_length) {
			control->ctl_data[1] = (IPTR) string->tmp_next;
			control->ctl_data[2] = 0;
		}
		control->ctl_segment_length = length;
		return (!outOfBuffer) ? FB_SUCCESS : isc_segment;
	}

	case isc_blob_filter_put_segment:
	case isc_blob_filter_create:
	case isc_blob_filter_seek:
	case isc_blob_filter_open:
		return isc_uns_ext;

	case isc_blob_filter_alloc:
	case isc_blob_filter_free:
		return FB_SUCCESS;

	default:
		BUGCHECK(289);			// Unknown blob filter ACTION
		return isc_uns_ext;