The tracecmd_peek_next_data() is similar to tracecmd_read_next_data()
but it doesn't consume the record.
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
trace-cmd.h | 3 +++
trace-input.c | 43 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
diff --git a/trace-cmd.h b/trace-cmd.h
index cef2458..5798345 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -164,6 +164,9 @@ struct pevent_record *
tracecmd_read_next_data(struct tracecmd_input *handle, int *rec_cpu);
struct pevent_record *
+tracecmd_peek_next_data(struct tracecmd_input *handle, int *rec_cpu);
+
+struct pevent_record *
tracecmd_read_at(struct tracecmd_input *handle, unsigned long long offset,
int *cpu);
struct pevent_record *
diff --git a/trace-input.c b/trace-input.c
index 2fea066..e825328 100644
--- a/trace-input.c
+++ b/trace-input.c
@@ -1787,6 +1787,49 @@ tracecmd_read_next_data(struct tracecmd_input *handle,
int *rec_cpu)
}
/**
+ * tracecmd_peek_next_data - return the next record
+ * @handle: input handle to the trace.dat file
+ * @rec_cpu: return pointer to the CPU that the record belongs to
+ *
+ * This returns the next record by time. This is different than
+ * tracecmd_peek_data in that it looks at all CPUs. It does a peek
+ * at each CPU and the record with the earliest time stame is
+ * returned. If @rec_cpu is not NULL it gets the CPU id the record was
+ * on. It does not increment the CPU iterator.
+ */
+struct pevent_record *
+tracecmd_peek_next_data(struct tracecmd_input *handle, int *rec_cpu)
+{
+ unsigned long long ts;
+ struct pevent_record *record, *next_record = NULL;
+ int next_cpu;
+ int cpu;
+
+ if (rec_cpu)
+ *rec_cpu = -1;
+
+ next_cpu = -1;
+ ts = 0;
+
+ for (cpu = 0; cpu < handle->cpus; cpu++) {
+ record = tracecmd_peek_data(handle, cpu);
+ if (record && (!next_record || record->ts < ts)) {
+ ts = record->ts;
+ next_cpu = cpu;
+ next_record = record;
+ }
+ }
+
+ if (next_record) {
+ if (rec_cpu)
+ *rec_cpu = next_cpu;
+ return next_record;
+ }
+
+ return NULL;
+}
+
+/**
* tracecmd_read_prev - read the record before the given record
* @handle: input handle to the trace.dat file
* @record: the record to use to find the previous record.
--
2.9.0
