From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Fri, 19 Feb 2016 02:34:12 +0000 (-0500)
Subject: ir: add bt_ctf_clock_ns_from_value() utility
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=4ef18cab9e8958617b5dd7c39105d4602c5535c2

ir: add bt_ctf_clock_ns_from_value() utility

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/formats/ctf/ir/clock.c b/formats/ctf/ir/clock.c
index 2e765430..253b033d 100644
--- a/formats/ctf/ir/clock.c
+++ b/formats/ctf/ir/clock.c
@@ -325,6 +325,19 @@ end:
 	return ret;
 }
 
+uint64_t ns_from_value(uint64_t frequency, uint64_t value)
+{
+	uint64_t ns;
+
+	if (frequency == 1000000000) {
+		ns = value;
+	} else {
+		ns = (uint64_t) ((1e9 * (double) value) / (double) frequency);
+	}
+
+	return ns;
+}
+
 int bt_ctf_clock_get_time(struct bt_ctf_clock *clock, int64_t *time)
 {
 	int ret = 0;
@@ -343,13 +356,7 @@ int bt_ctf_clock_get_time(struct bt_ctf_clock *clock, int64_t *time)
 		goto end;
 	}
 
-	/* Common case where cycles are actually nanoseconds */
-	if (clock->frequency == 1000000000) {
-		*time = (int64_t) clock->value;
-	} else {
-		*time = (int64_t) ((1e9 * (double) clock->value) /
-			(double) clock->frequency);
-	}
+	*time = (int64_t) ns_from_value(clock->frequency, clock->value);
 
 end:
 	return ret;
@@ -512,3 +519,24 @@ void bt_ctf_clock_destroy(struct bt_object *obj)
 
 	g_free(clock);
 }
+
+int64_t bt_ctf_clock_ns_from_value(struct bt_ctf_clock *clock, uint64_t value)
+{
+	int64_t ns = -1ULL;
+
+	if (!clock) {
+		goto end;
+	}
+
+	/* Initialize nanosecond timestamp to clock's offset in seconds */
+	ns = clock->offset_s * 1000000000;
+
+	/* Add offset in cycles, converted to nanoseconds */
+	ns += ns_from_value(clock->frequency, clock->offset);
+
+	/* Add given value, converter to nanoseconds */
+	ns += ns_from_value(clock->frequency, value);
+
+end:
+	return ns;
+}
diff --git a/include/babeltrace/ctf-ir/clock.h b/include/babeltrace/ctf-ir/clock.h
index ec08810b..e35882e0 100644
--- a/include/babeltrace/ctf-ir/clock.h
+++ b/include/babeltrace/ctf-ir/clock.h
@@ -237,6 +237,9 @@ extern const unsigned char *bt_ctf_clock_get_uuid(struct bt_ctf_clock *clock);
 extern int bt_ctf_clock_set_uuid(struct bt_ctf_clock *clock,
 		const unsigned char *uuid);
 
+extern int64_t bt_ctf_clock_ns_from_value(struct bt_ctf_clock *clock,
+		uint64_t value);
+
 #ifdef __cplusplus
 }
 #endif