Add client notification API

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

diff --git a/src/common/notification.c b/src/common/notification.c
new file mode 100644 (file)
index 0000000..5062ca5
--- /dev/null
+++ b/src/common/notification.c
@@ -0,0 +1,176 @@
+/*
+ * 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
+ssize_t lttng_notification_serialize(struct lttng_notification *notification,
+               char *buf)
+{
+       ssize_t ret, condition_size, evaluation_size, offset = 0;
+       struct lttng_notification_comm notification_comm;
+
+       if (!notification) {
+               ret = -1;
+               goto end;
+       }
+
+       offset += sizeof(notification_comm);
+       condition_size = lttng_condition_serialize(notification->condition,
+                       buf ? (buf + offset) : NULL);
+       if (condition_size < 0) {
+               ret = condition_size;
+               goto end;
+       }
+       offset += condition_size;
+
+       evaluation_size = lttng_evaluation_serialize(notification->evaluation,
+                       buf ? (buf + offset) : NULL);
+       if (evaluation_size < 0) {
+               ret = evaluation_size;
+               goto end;
+       }
+       offset += evaluation_size;
+
+       if (buf) {
+               notification_comm.length =
+                               (uint32_t) (condition_size + evaluation_size);
+               memcpy(buf, &notification_comm, sizeof(notification_comm));
+       }
+       ret = offset;
+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;
+}