Use the dynamic buffer to serialize notification objects

[lttng-tools.git] / src / common / notification.c

/*
 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License, version 2.1 only,
 * as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <lttng/notification/notification-internal.h>
#include <lttng/condition/condition-internal.h>
#include <lttng/condition/evaluation-internal.h>
#include <lttng/condition/condition.h>
#include <lttng/condition/evaluation.h>
#include <assert.h>

LTTNG_HIDDEN
struct lttng_notification *lttng_notification_create(
		struct lttng_condition *condition,
		struct lttng_evaluation *evaluation)
{
	struct lttng_notification *notification = NULL;

	if (!condition || !evaluation) {
		goto end;
	}

	notification = zmalloc(sizeof(struct lttng_notification));
	if (!notification) {
		goto end;
	}

	notification->condition = condition;
	notification->evaluation = evaluation;
	notification->owns_elements = false;
end:
	return notification;
}

LTTNG_HIDDEN
int lttng_notification_serialize(struct lttng_notification *notification,
		struct lttng_dynamic_buffer *buf)
{
	int ret;
	size_t header_offset, size_before_payload;
	struct lttng_notification_comm notification_comm = { 0 };
	struct lttng_notification_comm *header;

	header_offset = buf->size;
	ret = lttng_dynamic_buffer_append(buf, &notification_comm,
			sizeof(notification_comm));

	size_before_payload = buf->size;
	ret = lttng_condition_serialize(notification->condition,
			buf);
	if (ret) {
		goto end;
	}

	ret = lttng_evaluation_serialize(notification->evaluation, buf);
	if (ret) {
		goto end;
	}

	/* Update payload size. */
	header = (struct lttng_notification_comm *) ((char *) buf->data + header_offset);
	header->length = (uint32_t) (buf->size - size_before_payload);
end:
	return ret;

}

LTTNG_HIDDEN
ssize_t lttng_notification_create_from_buffer(
		const struct lttng_buffer_view *src_view,
		struct lttng_notification **notification)
{
	ssize_t ret, notification_size = 0, condition_size, evaluation_size;
	const struct lttng_notification_comm *notification_comm;
	struct lttng_condition *condition;
	struct lttng_evaluation *evaluation;
	struct lttng_buffer_view condition_view;
	struct lttng_buffer_view evaluation_view;

	if (!src_view || !notification) {
		ret = -1;
		goto end;
	}

	notification_comm =
			(const struct lttng_notification_comm *) src_view->data;
	notification_size += sizeof(*notification_comm);

	/* struct lttng_condition */
	condition_view = lttng_buffer_view_from_view(src_view,
			sizeof(*notification_comm), -1);
	condition_size = lttng_condition_create_from_buffer(&condition_view,
			&condition);
	if (condition_size < 0) {
		ret = condition_size;
		goto end;
	}
	notification_size += condition_size;

	/* struct lttng_evaluation */
	evaluation_view = lttng_buffer_view_from_view(&condition_view,
			condition_size, -1);
	evaluation_size = lttng_evaluation_create_from_buffer(&evaluation_view,
			&evaluation);
	if (evaluation_size < 0) {
		ret = evaluation_size;
		goto end;
	}
	notification_size += evaluation_size;

	/* Unexpected size of inner-elements; the buffer is corrupted. */
	if ((ssize_t) notification_comm->length !=
			condition_size + evaluation_size) {
		ret = -1;
		goto error;
	}

	*notification = lttng_notification_create(condition, evaluation);
	if (!*notification) {
		ret = -1;
		goto error;
	}
	ret = notification_size;
	(*notification)->owns_elements = true;
end:
	return ret;
error:
	lttng_condition_destroy(condition);
	lttng_evaluation_destroy(evaluation);
	return ret;
}

void lttng_notification_destroy(struct lttng_notification *notification)
{
	if (!notification) {
		return;
	}

	if (notification->owns_elements) {
		lttng_condition_destroy(notification->condition);
		lttng_evaluation_destroy(notification->evaluation);
	}
	free(notification);
}

const struct lttng_condition *lttng_notification_get_condition(
		struct lttng_notification *notification)
{
	return notification ? notification->condition : NULL;
}

const struct lttng_evaluation *lttng_notification_get_evaluation(
		struct lttng_notification *notification)
{
	return notification ? notification->evaluation : NULL;
}