metrics: new metrics interface

Signed-off-by: Eduardo Silva <[email protected]>

include/fluent-bit/flb_metrics.h

@@ -0,0 +1,42 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/* Fluent Bit
+ * ==========
+ * Copyright (C) 2015-2017 Treasure Data Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http:https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLB_METRICS_H
+#define FLB_METRICS_H
+
+struct flb_metric {
+ int id;
+ char title[32];
+ size_t val;
+ struct mk_list _head;
+};
+
+struct flb_metrics {
+ char title[32]; /* Title or id for this metrics context */
+ int count; /* Total count of metrics registered */
+ struct mk_list list; /* Head of metrics list */
+};
+
+struct flb_metrics *flb_metrics_create(char *title);
+struct flb_metric *flb_metrics_get_id(int id, struct flb_metrics *metrics);
+int flb_metrics_add(int id, char *title, struct flb_metrics *metrics);
+int flb_metrics_sum(int id, size_t val, struct flb_metrics *metrics);
+int flb_metrics_destroy(struct flb_metrics *metrics);
+
+#endif

src/flb_metrics.c

@@ -0,0 +1,176 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/* Fluent Bit
+ * ==========
+ * Copyright (C) 2015-2017 Treasure Data Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http:https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Metrics interface is a helper to gather general metrics from the core or
+ * plugins at runtime.
+ */
+
+#include <fluent-bit/flb_info.h>
+#include <fluent-bit/flb_mem.h>
+#include <fluent-bit/flb_utils.h>
+#include <fluent-bit/flb_metrics.h>
+
+static int id_exists(int id, struct flb_metrics *metrics)
+{
+ struct mk_list *head;
+ struct flb_metric *metric;
+
+ mk_list_foreach(head, &metrics->list) {
+ metric = mk_list_entry(head, struct flb_metric, _head);
+ if (metric->id == id) {
+ return FLB_TRUE;
+ }
+ }
+
+ return FLB_FALSE;
+}
+
+static int id_get(struct flb_metrics *metrics)
+{
+ int id;
+ int ret = FLB_FALSE;
+
+ /* Try to use 'count' as an id */
+ id = metrics->count;
+
+ while ((ret = id_exists(id, metrics)) == FLB_TRUE) {
+ id++;
+ }
+
+ return id;
+}
+
+struct flb_metric *flb_metrics_get_id(int id, struct flb_metrics *metrics)
+{
+ struct mk_list *head;
+ struct flb_metric *m;
+
+ mk_list_foreach(head, &metrics->list) {
+ m = mk_list_entry(head, struct flb_metric, _head);
+ if (m->id == id) {
+ return m;
+ }
+ }
+
+ return NULL;
+}
+
+struct flb_metrics *flb_metrics_create(char *title)
+{
+ int ret;
+ struct flb_metrics *metrics;
+
+ metrics = flb_malloc(sizeof(struct flb_metrics));
+ if (!metrics) {
+ flb_errno();
+ return NULL;
+ }
+ metrics->count = 0;
+
+ ret = snprintf(metrics->title, sizeof(metrics->title) - 1, "%s", title);
+ if (ret == -1) {
+ flb_errno();
+ flb_free(metrics);
+ return NULL;
+ }
+
+ mk_list_init(&metrics->list);
+ return metrics;
+}
+
+int flb_metrics_add(int id, char *title, struct flb_metrics *metrics)
+{
+ int ret;
+ struct flb_metric *m;
+
+ /* Create context */
+ m = flb_malloc(sizeof(struct flb_metric));
+ if (!m) {
+ flb_errno();
+ return -1;
+ }
+ m->val = 0;
+
+ /* Write title */
+ ret = snprintf(metrics->title, sizeof(metrics->title) - 1, "%s", title);
+ if (ret == -1) {
+ flb_errno();
+ flb_free(m);
+ return -1;
+ }
+
+ /* Assign an ID */
+ if (id >= 0) {
+ /* Check this new ID is available */
+ if (id_exists(id, metrics) == FLB_TRUE) {
+ flb_error("[metrics] id=%i already exists for metric '%s'",
+ id, metrics->title);
+ flb_free(m);
+ return -1;
+ }
+ }
+ else {
+ id = id_get(metrics);
+ }
+
+ /* Link to parent list */
+ mk_list_add(&m->_head, &metrics->list);
+ m->id = id;
+ metrics->count++;
+
+ return id;
+}
+
+int flb_metrics_sum(int id, size_t val, struct flb_metrics *metrics)
+{
+ struct flb_metric *m;
+
+ m = flb_metrics_get_id(id, metrics);
+ if (!m) {
+ return -1;
+ }
+
+ m->val += val;
+ return 0;
+}
+
+int flb_metrics_destroy(struct flb_metrics *metrics)
+{
+ int count = 0;
+ struct mk_list *tmp;
+ struct mk_list *head;
+ struct flb_metric *m;
+
+ mk_list_foreach_safe(head, tmp, &metrics->list) {
+ m = mk_list_entry(head, struct flb_metric, _head);
+ mk_list_del(&m->_head);
+ flb_free(m);
+ count++;
+ }
+
+ flb_free(metrics);
+ return count;
+}
+
+int flb_metrics_print(struct flb_metrics *metrics)
+{
+ (void) metrics;
+ return 0;
+}