Function shrink_buffer

util/cbfstool/elogtool.c:155–194

* Shrinks buffer by ~bytes_to_shrink, then appends a LOG_CLEAR event, * and finally fills the remaining area with EOL events. * Buffer offset must point to a valid event_header struct. */

 * Buffer offset must point to a valid event_header struct.
 */
static int shrink_buffer(const struct buffer *buf, size_t bytes_to_shrink)
{
	struct buffer copy, *iter = ©
	const struct event_header *event;
	uint32_t cleared;
	int remaining;
	uint8_t *data;

	assert(buffer_offset(buf) >= sizeof(struct elog_header));

	buffer_clone(&copy, buf);

	/* Save copy of first event for later */
	data = buffer_get(buf);

	/* Set buffer offset pointing to the event right after bytes_to_shrink */
	while (buffer_offset(iter) < bytes_to_shrink) {
		event = buffer_get(iter);
		assert(!(event->type == ELOG_TYPE_EOL || event->length == 0));

		buffer_seek(iter, event->length);
	}

	/* Must be relative to the buffer offset */
	cleared = buffer_offset(iter) - buffer_offset(buf);
	remaining = buffer_size(iter);

	/* Overlapping copy */
	memmove(data, data + cleared, remaining);
	memset(data + remaining, ELOG_TYPE_EOL, cleared);

	/* Re-init copy to have a clean offset. Needed for init_event() */
	buffer_clone(&copy, buf);
	buffer_seek(&copy, next_available_event_offset(&copy));

	if (!eventlog_init_event(&copy, ELOG_TYPE_LOG_CLEAR, &cleared, sizeof(cleared)))
		return ELOGTOOL_EXIT_NOT_ENOUGH_BUFFER_SPACE;

	return ELOGTOOL_EXIT_SUCCESS;
}

static int cmd_list(const struct buffer *buf, enum elogtool_flag flags)
{