From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Add a query to the iterator that will return the values of the last entry
that matches the keys returned by the last call of traceeval_iterator_next().
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
include/traceeval-hist.h | 2 ++
samples/task-eval.c | 2 +-
src/histograms.c | 30 ++++++++++++++++++++++++++++++
3 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/include/traceeval-hist.h b/include/traceeval-hist.h
index 0cee9bcbeb83..837a74f61a66 100644
--- a/include/traceeval-hist.h
+++ b/include/traceeval-hist.h
@@ -186,5 +186,7 @@ int traceeval_iterator_sort_custom(struct traceeval_iterator *iter,
traceeval_cmp_fn sort_fn, void *data);
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);
#endif /* __LIBTRACEEVAL_HIST_H__ */
diff --git a/samples/task-eval.c b/samples/task-eval.c
index 66d0c40dc0c8..18e07f44e11e 100644
--- a/samples/task-eval.c
+++ b/samples/task-eval.c
@@ -836,7 +836,7 @@ static void display_processes(struct traceeval *teval,
struct process_data *pdata = NULL;
const char *comm = keys[0].cstring;
- ret = traceeval_query(teval_data, keys, &results);
+ ret = traceeval_iterator_query(iter, &results);
if (ret < 0)
pdie("Could not query iterator");
if (ret < 1)
diff --git a/src/histograms.c b/src/histograms.c
index 66bdc1769985..4f603ce36c8c 100644
--- a/src/histograms.c
+++ b/src/histograms.c
@@ -1306,3 +1306,33 @@ int traceeval_iterator_next(struct traceeval_iterator *iter,
*keys = entry->keys;
return 1;
}
+
+/**
+ * traceeval_iterator_query - return the results of the last entry in the iterator
+ * @iter: The iterator to retrieve the entry results from
+ * @results: The returned results of the last entry (if exists)
+ *
+ * This returns the @results of the values from the last instance of
+ * traceeval_iterator_next(). It is equivalent of calling:
+ *
+ * traceeval_query_size() with the keys returned by traceeval_iterator_next().
+ *
+ * Except that it will always quickly return the last entry, whereas the
+ * traceeval_query_size() will reset the cached next_entry and do a full
+ * lookup again.
+ *
+ * Returns 1 if another entry is returned, or 0 if not (or negative on error)
+ */
+int traceeval_iterator_query(struct traceeval_iterator *iter,
+ const union traceeval_data **results)
+{
+ struct entry *entry;
+
+ if (iter->next < 1 || iter->next > iter->nr_entries)
+ return 0;
+
+ entry = iter->entries[iter->next - 1];
+ *results = entry->vals;
+
+ return 1;
+}
--
2.40.1
|