Rename 'statistics.c' to 'counter.c'
With stat_item, stats.c and stats_statsd.c, it is becoming a bit
difficult to understand file naming. Also, the 'statistics.c' file
actually only contained osmo_counter handling, so let's rename it to
counter.c altogether.
Change-Id: I2cfb2310543902b7da46cb15a76e2da317eaed7d
diff --git a/include/osmocom/core/counter.h b/include/osmocom/core/counter.h
new file mode 100644
index 0000000..f4429cd
--- /dev/null
+++ b/include/osmocom/core/counter.h
@@ -0,0 +1,60 @@
+#pragma once
+
+/*! \file counter.h
+ * Common routines regarding counter handling */
+
+/*! structure representing a single counter */
+struct osmo_counter {
+ struct llist_head list; /*!< internal list head */
+ const char *name; /*!< human-readable name */
+ const char *description; /*!< humn-readable description */
+ unsigned long value; /*!< current value */
+ unsigned long previous; /*!< previous value */
+};
+
+/*! Decrement counter */
+static inline void osmo_counter_dec(struct osmo_counter *ctr)
+{
+ ctr->value--;
+}
+
+/*! Increment counter */
+static inline void osmo_counter_inc(struct osmo_counter *ctr)
+{
+ ctr->value++;
+}
+
+/*! Get current value of counter */
+static inline unsigned long osmo_counter_get(struct osmo_counter *ctr)
+{
+ return ctr->value;
+}
+
+/*! Reset current value of counter to 0 */
+static inline void osmo_counter_reset(struct osmo_counter *ctr)
+{
+ ctr->value = 0;
+}
+
+/*! Allocate a new counter */
+struct osmo_counter *osmo_counter_alloc(const char *name);
+
+/*! Free the specified counter
+ * \param[in] ctr Counter
+ */
+void osmo_counter_free(struct osmo_counter *ctr);
+
+/*! Iterate over all counters
+ * \param[in] handle_counter Call-back function, aborts if rc < 0
+ * \param[in] data Private dtata handed through to \a handle_counter
+ */
+int osmo_counters_for_each(int (*handle_counter)(struct osmo_counter *, void *), void *data);
+
+/*! Resolve counter by human-readable name
+ * \param[in] name human-readable name of counter
+ * \returns pointer to counter (\ref osmo_counter) or NULL otherwise
+ */
+struct osmo_counter *osmo_counter_get_by_name(const char *name);
+
+/*! Return the counter difference since the last call to this function */
+int osmo_counter_difference(struct osmo_counter *ctr);