shared: Add timespec_from_proto helper function

Add helper function to convert tv_sec_hi, tv_sec_lo, tv_nsec triplets,
used for sending high-resolution timestamp data over the wayland
protocol, to struct timespec values. Replace existing conversion code
with the helper function.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

tests/presentation-test.c

@@ -34,6 +34,7 @@
 
 #include "shared/helpers.h"
 #include "shared/xalloc.h"
+#include "shared/timespec-util.h"
 #include "weston-test-client-helper.h"
 #include "presentation-time-client-protocol.h"
 
@@ -85,14 +86,6 @@ struct feedback {
 	uint32_t flags;
 };
 
-static void
-timespec_from_proto(struct timespec *tm, uint32_t tv_sec_hi,
-		    uint32_t tv_sec_lo, uint32_t tv_nsec)
-{
-	tm->tv_sec = ((uint64_t)tv_sec_hi << 32) + tv_sec_lo;
-	tm->tv_nsec = tv_nsec;
-}
-
 static void
 feedback_sync_output(void *data,
 		     struct wp_presentation_feedback *presentation_feedback,

tests/timespec-test.c

@@ -238,6 +238,23 @@ ZUC_TEST(timespec_test, timespec_from_msec)
 	ZUC_ASSERT_EQ(1000000, a.tv_nsec);
 }
 
+ZUC_TEST(timespec_test, timespec_from_proto)
+{
+	struct timespec a;
+
+	timespec_from_proto(&a, 0, 0, 0);
+	ZUC_ASSERT_EQ(0, a.tv_sec);
+	ZUC_ASSERT_EQ(0, a.tv_nsec);
+
+	timespec_from_proto(&a, 0, 1234, 9999);
+	ZUC_ASSERT_EQ(1234, a.tv_sec);
+	ZUC_ASSERT_EQ(9999, a.tv_nsec);
+
+	timespec_from_proto(&a, 0x1234, 0x5678, 1);
+	ZUC_ASSERT_EQ((time_t)0x0000123400005678LL, a.tv_sec);
+	ZUC_ASSERT_EQ(1, a.tv_nsec);
+}
+
 ZUC_TEST(timespec_test, timespec_is_zero)
 {
 	struct timespec zero = { 0 };