trace-cmd: Move merge sort of reading records into library

The merge sort of reading the record timestamps and ording the
records by time, regardless of CPU, has been moved from the
trace-cmd.c file into the libtracecmd library code trace-input.c.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 48 insertions, 0 deletions

diff --git a/trace-input.c b/trace-input.c
index dc1167a..ece0aab 100644
--- a/trace-input.c
+++ b/trace-input.c
@@ -1339,6 +1339,54 @@ tracecmd_read_data(struct tracecmd_input *handle, int cpu)
         return record;
 }
 
+/**
+ * tracecmd_read_next_data - read 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_read_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. The CPU cursor of the returned record is moved to the
+ * next record.
+ *
+ * Multiple reads of this function will return a serialized list
+ * of all records for all CPUs in order of time stamp.
+ *
+ * The record returned must be freed.
+ */
+struct record *
+tracecmd_read_next_data(struct tracecmd_input *handle, int *rec_cpu)
+{
+        unsigned long long ts;
+        struct record *record;
+        int next;
+        int cpu;
+
+        if (rec_cpu)
+                *rec_cpu = -1;
+
+        next = -1;
+        ts = 0;
+
+        for (cpu = 0; cpu < handle->cpus; cpu++) {
+                record = tracecmd_peek_data(handle, cpu);
+                if (record && (!ts || record->ts < ts)) {
+                        ts = record->ts;
+                        next = cpu;
+                }
+        }
+
+        if (next >= 0) {
+                if (rec_cpu)
+                        *rec_cpu = next;
+                return tracecmd_read_data(handle, next);
+        }
+
+        return NULL;
+}
+
 static int init_cpu(struct tracecmd_input *handle, int cpu)
 {
         struct cpu_data *cpu_data = &handle->cpu_data[cpu];