[PATCH 3/9] libtraceeval: Add traceeval_iterator_stat()

[Steven Rostedt <rostedt@xxxxxxxxxxx>]

From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>

Add traceeval_iterator_stat() that will return a stat of a value of the
current entry from a traceeval_iterator_next() loop.

Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 include/traceeval-hist.h |  2 ++
 samples/task-eval.c      |  6 ++---
 src/histograms.c         | 47 ++++++++++++++++++++++++++++++++--------
 3 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/include/traceeval-hist.h b/include/traceeval-hist.h
index 837a74f61a66..d511c9c5f14c 100644
--- a/include/traceeval-hist.h
+++ b/include/traceeval-hist.h
@@ -188,5 +188,7 @@ int traceeval_iterator_next(struct traceeval_iterator *iter,
 			    const union traceeval_data **keys);
 int traceeval_iterator_query(struct traceeval_iterator *iter,
 			     const union traceeval_data **results);
+struct traceeval_stat *traceeval_iterator_stat(struct traceeval_iterator *iter,
+					       struct traceeval_type *type);
 
 #endif /* __LIBTRACEEVAL_HIST_H__ */
diff --git a/samples/task-eval.c b/samples/task-eval.c
index 18e07f44e11e..bde167d1219b 100644
--- a/samples/task-eval.c
+++ b/samples/task-eval.c
@@ -706,7 +706,7 @@ static void display_cpus(struct traceeval *teval)
 		int state = keys[1].number;
 		int cpu = keys[0].number;
 
-		stat = traceeval_stat(teval, keys, &delta_vals[0]);
+		stat = traceeval_iterator_stat(iter, &delta_vals[0]);
 		if (!stat)
 			continue; // die?
 
@@ -773,7 +773,7 @@ static void display_threads(struct traceeval *teval)
 		int state = keys[1].number;
 		int tid = keys[0].number;
 
-		stat = traceeval_stat(teval, keys, &delta_vals[0]);
+		stat = traceeval_iterator_stat(iter, &delta_vals[0]);
 		if (!stat)
 			continue; // die?
 
@@ -875,7 +875,7 @@ static void display(struct task_data *tdata)
 	while (traceeval_iterator_next(iter, &keys) > 0) {
 		int state = keys[1].number;
 
-		stat = traceeval_stat(teval, keys, &delta_vals[0]);
+		stat = traceeval_iterator_stat(iter, &delta_vals[0]);
 		if (!stat)
 			continue;
 
diff --git a/src/histograms.c b/src/histograms.c
index 4f603ce36c8c..fddd0f3587e2 100644
--- a/src/histograms.c
+++ b/src/histograms.c
@@ -812,16 +812,11 @@ static int update_entry(struct traceeval *teval, struct entry *entry,
 	return -1;
 }
 
-struct traceeval_stat *traceeval_stat(struct traceeval *teval,
-				      const union traceeval_data *keys,
-				      struct traceeval_type *type)
+static bool is_stat_type(struct traceeval_type *type)
 {
-	struct entry *entry;
-	int ret;
-
 	/* Only value numbers have stats */
 	if (!(type->flags & TRACEEVAL_FL_VALUE))
-		return NULL;
+		return false;
 
 	switch (type->type) {
 	case TRACEEVAL_TYPE_NUMBER:
@@ -829,10 +824,21 @@ struct traceeval_stat *traceeval_stat(struct traceeval *teval,
 	case TRACEEVAL_TYPE_NUMBER_32:
 	case TRACEEVAL_TYPE_NUMBER_16:
 	case TRACEEVAL_TYPE_NUMBER_8:
-		break;
+		return true;
 	default:
-		return NULL;
+		return false;
 	}
+}
+
+struct traceeval_stat *traceeval_stat(struct traceeval *teval,
+				      const union traceeval_data *keys,
+				      struct traceeval_type *type)
+{
+	struct entry *entry;
+	int ret;
+
+	if (!is_stat_type(type))
+		return NULL;
 
 	ret = get_entry(teval, keys, &entry);
 	if (ret <= 0)
@@ -1336,3 +1342,26 @@ int traceeval_iterator_query(struct traceeval_iterator *iter,
 
 	return 1;
 }
+
+/**
+ * traceeval_iterator_stat - return the stats from the last iterator entry
+ * @iter: The iterator to retrieve the stats from
+ * @type: The value type to get the stat from
+ *
+ * Returns the stats of the @type for the current iterator entry on success,
+ * or NULL if not found or an error occurred.
+ */
+struct traceeval_stat *traceeval_iterator_stat(struct traceeval_iterator *iter,
+					       struct traceeval_type *type)
+{
+	struct entry *entry;
+
+	if (!is_stat_type(type))
+		return NULL;
+
+	if (iter->next < 1 || iter->next > iter->nr_entries)
+		return NULL;
+
+	entry = iter->entries[iter->next - 1];
+	return &entry->val_stats[type->index];
+}
-- 
2.40.1