1 files changed, 68 insertions, 0 deletions
diff --git a/src/lib/metrics/metrics_store_entry.h b/src/lib/metrics/metrics_store_entry.h
new file mode 100644
index 0000000000..8e8a8f3917
--- /dev/null
+++ b/src/lib/metrics/metrics_store_entry.h
@@ -0,0 +1,68 @@
+/* Copyright (c) 2020, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file metrics_store_entry.h
+ * @brief Header for lib/metrics/metrics_store_entry.c
+ **/
+
+#ifndef TOR_LIB_METRICS_METRICS_STORE_ENTRY_H
+#define TOR_LIB_METRICS_METRICS_STORE_ENTRY_H
+
+#include "lib/cc/torint.h"
+
+#include "lib/metrics/metrics_common.h"
+
+#ifdef METRICS_STORE_ENTRY_PRIVATE
+
+/** Metrics store entry. They reside in a metrics_store_t object and are
+ * opaque to the outside world. */
+struct metrics_store_entry_t {
+  /** Type of entry. */
+  metrics_type_t type;
+
+  /** Name. */
+  char *name;
+
+  /** Help comment string. */
+  char *help;
+
+  /** Labels attached to that entry. If NULL, no labels.
+   *
+   * Labels are used to add extra context to a metrics. For example, a label
+   * could be an onion address so the metrics can be differentiate. */
+  smartlist_t *labels;
+
+  /* Actual data. */
+  union {
+    metrics_counter_t counter;
+    metrics_gauge_t gauge;
+  } u;
+};
+
+#endif /* METRICS_STORE_ENTRY_PRIVATE */
+
+typedef struct metrics_store_entry_t metrics_store_entry_t;
+
+/* Allocators. */
+metrics_store_entry_t *metrics_store_entry_new(const metrics_type_t type,
+                                               const char *name,
+                                               const char *help);
+
+void metrics_store_entry_free_(metrics_store_entry_t *entry);
+#define metrics_store_entry_free(entry) \
+  FREE_AND_NULL(metrics_store_entry_t, metrics_store_entry_free_, (entry));
+
+/* Accessors. */
+int64_t metrics_store_entry_get_value(const metrics_store_entry_t *entry);
+bool metrics_store_entry_has_label(const metrics_store_entry_t *entry,
+                                   const char *label);
+
+/* Modifiers. */
+void metrics_store_entry_add_label(metrics_store_entry_t *entry,
+                                   const char *label);
+void metrics_store_entry_reset(metrics_store_entry_t *entry);
+void metrics_store_entry_update(metrics_store_entry_t *entry,
+                                const int64_t value);
+
+#endif /* !defined(TOR_LIB_METRICS_METRICS_STORE_ENTRY_H) */