stat_item: make next_id argument name consistent

Let osmo_stat_item_get_next, osmo_stat_item_discard,
osmo_stat_item_discard_all consistently refer to their next_id arg as
such (and not idx or next_idx). It refers to an ID (item->values[i].id),
not an index (item->values[i]), and it is always the next one, never the
current one.

Do the same change for _index/_idx variables in stats.c, which are used
as arguments to these functions. Replace rd_ with next_id_ in
stats_test.c, too.

Related: OS#5088
Change-Id: I5dd566b08dff7174d1790f49abd2d6ac020e120e

2 files changed, 26 insertions, 26 deletions

diff --git a/src/stat_item.c b/src/stat_item.c
index ba364640..31298fd7 100644
--- a/src/stat_item.c
+++ b/src/stat_item.c
@@ -195,33 +195,33 @@ void osmo_stat_item_set(struct osmo_stat_item *item, int32_t value)
 }
 
 /*! Retrieve the next value from the osmo_stat_item object.
- * If a new value has been set, it is returned. The idx is used to decide
+ * If a new value has been set, it is returned. The next_id is used to decide
  * which value to return.
- * On success, *idx is updated to refer to the next unread value. If
- * values have been missed due to FIFO overflow, *idx is incremented by
+ * On success, *next_id is updated to refer to the next unread value. If
+ * values have been missed due to FIFO overflow, *next_id is incremented by
  * (1 + num_lost).
  * This way, the osmo_stat_item object can be kept stateless from the reader's
  * perspective and therefore be used by several backends simultaneously.
  *
- * \param val	the osmo_stat_item object
- * \param idx	identifies the next value to be read
- * \param value	a pointer to store the value
+ * \param val     the osmo_stat_item object
+ * \param next_id identifies the next value to be read
+ * \param value   a pointer to store the value
  * \returns  the increment of the index (0: no value has been read,
  *           1: one value has been taken,
  *           (1+n): n values have been skipped, one has been taken)
  */
-int osmo_stat_item_get_next(const struct osmo_stat_item *item, int32_t *next_idx,
+int osmo_stat_item_get_next(const struct osmo_stat_item *item, int32_t *next_id,
 	int32_t *value)
 {
 	const struct osmo_stat_item_value *next_value;
 	const struct osmo_stat_item_value *item_value = NULL;
-	int idx_delta;
+	int id_delta;
 	int next_offs;
 
 	next_offs = item->last_offs;
 	next_value = &item->values[next_offs];
 
-	while (next_value->id - *next_idx >= 0 &&
+	while (next_value->id - *next_id >= 0 &&
 		next_value->id != OSMO_STAT_ITEM_NOVALUE_ID)
 	{
 		item_value = next_value;
@@ -240,27 +240,27 @@ int osmo_stat_item_get_next(const struct osmo_stat_item *item, int32_t *next_idx
 
 	*value = item_value->value;
 
-	idx_delta = item_value->id + 1 - *next_idx;
+	id_delta = item_value->id + 1 - *next_id;
 
-	*next_idx = item_value->id + 1;
+	*next_id = item_value->id + 1;
 
-	return idx_delta;
+	return id_delta;
 }
 
-/*! Skip/discard all values of this item and update \a idx accordingly */
-int osmo_stat_item_discard(const struct osmo_stat_item *item, int32_t *idx)
+/*! Skip/discard all values of this item and update \a next_id accordingly */
+int osmo_stat_item_discard(const struct osmo_stat_item *item, int32_t *next_id)
 {
-	int discarded = item->values[item->last_offs].id + 1 - *idx;
-	*idx = item->values[item->last_offs].id + 1;
+	int discarded = item->values[item->last_offs].id + 1 - *next_id;
+	*next_id = item->values[item->last_offs].id + 1;
 
 	return discarded;
 }
 
-/*! Skip all values of all items and update \a idx accordingly */
-int osmo_stat_item_discard_all(int32_t *idx)
+/*! Skip all values of all items and update \a next_id accordingly */
+int osmo_stat_item_discard_all(int32_t *next_id)
 {
-	int discarded = global_value_id + 1 - *idx;
-	*idx = global_value_id + 1;
+	int discarded = global_value_id + 1 - *next_id;
+	*next_id = global_value_id + 1;
 
 	return discarded;
 }
diff --git a/src/stats.c b/src/stats.c
index f2820a45..88b733fd 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -107,7 +107,7 @@
 static LLIST_HEAD(osmo_stats_reporter_list);
 static void *osmo_stats_ctx = NULL;
 static int is_initialised = 0;
-static int32_t current_stat_item_index = 0;
+static int32_t current_stat_item_next_id = 0;
 
 static struct osmo_stats_config s_stats_config = {
 	.interval = STATS_DEFAULT_INTERVAL,
@@ -241,7 +241,7 @@ void osmo_stats_reporter_free(struct osmo_stats_reporter *srep)
 void osmo_stats_init(void *ctx)
 {
 	osmo_stats_ctx = ctx;
-	osmo_stat_item_discard_all(&current_stat_item_index);
+	osmo_stat_item_discard_all(&current_stat_item_next_id);
 
 	is_initialised = 1;
 	start_timer();
@@ -694,18 +694,18 @@ static int osmo_stat_item_handler(
 	struct osmo_stat_item_group *statg, struct osmo_stat_item *item, void *sctx_)
 {
 	struct osmo_stats_reporter *srep;
-	int32_t idx = current_stat_item_index;
+	int32_t next_id = current_stat_item_next_id;
 	int32_t value;
 	int have_value;
 
-	have_value = osmo_stat_item_get_next(item, &idx, &value) > 0;
+	have_value = osmo_stat_item_get_next(item, &next_id, &value) > 0;
 	if (!have_value) {
 		/* Send the last value in case a flush is requested */
 		value = osmo_stat_item_get_last(item);
 	} else {
 		int32_t next_val;
 		/* If we have multiple values only send the max */
-		while (osmo_stat_item_get_next(item, &idx, &next_val) > 0)
+		while (osmo_stat_item_get_next(item, &next_id, &next_val) > 0)
 			value = OSMO_MAX(value, next_val);
 	}
 
@@ -798,7 +798,7 @@ int osmo_stats_report()
 	osmo_stat_item_for_each_group(osmo_stat_item_group_handler, NULL);
 
 	/* global actions */
-	osmo_stat_item_discard_all(&current_stat_item_index);
+	osmo_stat_item_discard_all(&current_stat_item_next_id);
 	flush_all_reporters();
 	TRACE(LIBOSMOCORE_STATS_DONE());