reftable/system: add abstraction to retrieve time in milliseconds

We directly call gettimeofday(3p), which may not be available on some
platforms. Provide the infrastructure to let projects easily use their
own implementations of this function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 13 insertions, 23 deletions

diff --git a/reftable/stack.c b/reftable/stack.c
index fa87b46c37..1fba96ddb3 100644
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -365,45 +365,26 @@ done:
 	return err;
 }
 
-/* return negative if a before b. */
-static int tv_cmp(struct timeval *a, struct timeval *b)
-{
-	time_t diff = a->tv_sec - b->tv_sec;
-	int udiff = a->tv_usec - b->tv_usec;
-
-	if (diff != 0)
-		return diff;
-
-	return udiff;
-}
-
 static int reftable_stack_reload_maybe_reuse(struct reftable_stack *st,
 					     int reuse_open)
 {
 	char **names = NULL, **names_after = NULL;
-	struct timeval deadline;
+	uint64_t deadline;
 	int64_t delay = 0;
 	int tries = 0, err;
 	int fd = -1;
 
-	err = gettimeofday(&deadline, NULL);
-	if (err < 0)
-		goto out;
-	deadline.tv_sec += 3;
+	deadline = reftable_time_ms() + 3000;
 
 	while (1) {
-		struct timeval now;
-
-		err = gettimeofday(&now, NULL);
-		if (err < 0)
-			goto out;
+		uint64_t now = reftable_time_ms();
 
 		/*
 		 * Only look at deadlines after the first few times. This
 		 * simplifies debugging in GDB.
 		 */
 		tries++;
-		if (tries > 3 && tv_cmp(&now, &deadline) >= 0)
+		if (tries > 3 && now >= deadline)
 			goto out;
 
 		fd = open(st->list_file, O_RDONLY);
diff --git a/reftable/system.c b/reftable/system.c
index 4d7e366b55..cd76e56be8 100644
--- a/reftable/system.c
+++ b/reftable/system.c
@@ -4,6 +4,7 @@
 #include "basics.h"
 #include "reftable-error.h"
 #include "../lockfile.h"
+#include "../trace.h"
 #include "../tempfile.h"
 #include "../write-or-die.h"
 
@@ -137,3 +138,8 @@ int reftable_fsync(int fd)
 {
 	return fsync_component(FSYNC_COMPONENT_REFERENCE, fd);
 }
+
+uint64_t reftable_time_ms(void)
+{
+	return getnanotime() / 1000000;
+}
diff --git a/reftable/system.h b/reftable/system.h
index a7eb6acd4a..071bfa3d58 100644
--- a/reftable/system.h
+++ b/reftable/system.h
@@ -111,4 +111,7 @@ int flock_release(struct reftable_flock *l);
  */
 int flock_commit(struct reftable_flock *l);
 
+/* Report the time in milliseconds. */
+uint64_t reftable_time_ms(void);
+
 #endif