perf tools: Add time-based utility functions

Add function to parse a user time string of the form <start>,<stop>
where start and stop are time in sec.nsec format. Both start and stop
times are optional.

Add function to determine if a sample time is within a given time
time window of interest.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1480439746-42695-2-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/tools/perf/util/time-utils.c b/tools/perf/util/time-utils.c
new file mode 100644
index 000000000000..0443b2afd0cf
--- /dev/null
+++ b/tools/perf/util/time-utils.c
@@ -0,0 +1,85 @@
+#include <string.h>
+#include <sys/time.h>
+#include <time.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include "perf.h"
+#include "debug.h"
+#include "time-utils.h"
+#include "util.h"
+
+static int parse_timestr_sec_nsec(struct perf_time_interval *ptime,
+                                  char *start_str, char *end_str)
+{
+        if (start_str && (*start_str != '\0') &&
+            (parse_nsec_time(start_str, &ptime->start) != 0)) {
+                return -1;
+        }
+
+        if (end_str && (*end_str != '\0') &&
+            (parse_nsec_time(end_str, &ptime->end) != 0)) {
+                return -1;
+        }
+
+        return 0;
+}
+
+int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
+{
+        char *start_str, *end_str;
+        char *d, *str;
+        int rc = 0;
+
+        if (ostr == NULL || *ostr == '\0')
+                return 0;
+
+        /* copy original string because we need to modify it */
+        str = strdup(ostr);
+        if (str == NULL)
+                return -ENOMEM;
+
+        ptime->start = 0;
+        ptime->end = 0;
+
+        /* str has the format: <start>,<stop>
+         * variations: <start>,
+         *             ,<stop>
+         *             ,
+         */
+        start_str = str;
+        d = strchr(start_str, ',');
+        if (d) {
+                *d = '\0';
+                ++d;
+        }
+        end_str = d;
+
+        rc = parse_timestr_sec_nsec(ptime, start_str, end_str);
+
+        free(str);
+
+        /* make sure end time is after start time if it was given */
+        if (rc == 0 && ptime->end && ptime->end < ptime->start)
+                return -EINVAL;
+
+        pr_debug("start time %" PRIu64 ", ", ptime->start);
+        pr_debug("end time %" PRIu64 "\n", ptime->end);
+
+        return rc;
+}
+
+bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp)
+{
+        /* if time is not set don't drop sample */
+        if (timestamp == 0)
+                return false;
+
+        /* otherwise compare sample time to time window */
+        if ((ptime->start && timestamp < ptime->start) ||
+            (ptime->end && timestamp > ptime->end)) {
+                return true;
+        }
+
+        return false;
+}