p1400: use git-update-ref --stdin to test multiple transactions

pks-t · gitster · commit 21020430a4a0 · 2020-11-16T13:44:01.000-08:00
In commit 0a0fbbe (refs: remove lookup cache for reference-transaction hook, 2020-08-25), a new benchmark was added to p1400 which has the intention to exercise creation of multiple transactions in a single process. As git-update-ref wasn't yet able to create multiple transactions with a single run we instead used git-push. As its non-atomic version creates a transaction per reference update, this was the best approximation we could make at that point in time. Now that `git-update-ref --stdin` supports creation of multiple transactions, let's convert the benchmark to use that instead. It has less overhead and it's also a lot clearer what the actual intention is. Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/perf/p1400-update-ref.sh b/t/perf/p1400-update-ref.sh
@@ -7,13 +7,14 @@ test_description="Tests performance of update-ref"
 test_perf_fresh_repo
 
 test_expect_success "setup" '
-	git init --bare target-repo.git &&
 	test_commit PRE &&
 	test_commit POST &&
-	printf "create refs/heads/%d PRE\n" $(test_seq 1000) >create &&
-	printf "update refs/heads/%d POST PRE\n" $(test_seq 1000) >update &&
-	printf "delete refs/heads/%d POST\n" $(test_seq 1000) >delete &&
-	git update-ref --stdin <create
+	for i in $(test_seq 5000)
+	do
+		printf "start\ncreate refs/heads/%d PRE\ncommit\n" $i &&
+		printf "start\nupdate refs/heads/%d POST PRE\ncommit\n" $i &&
+		printf "start\ndelete refs/heads/%d POST\ncommit\n" $i
+	done >instructions
 '
 
 test_perf "update-ref" '
@@ -26,14 +27,7 @@ test_perf "update-ref" '
 '
 
 test_perf "update-ref --stdin" '
-	git update-ref --stdin <update &&
-	git update-ref --stdin <delete &&
-	git update-ref --stdin <create
-'
-
-test_perf "nonatomic push" '
-	git push ./target-repo.git $(test_seq 1000) &&
-	git push --delete ./target-repo.git $(test_seq 1000)
+	git update-ref --stdin <instructions >/dev/null
 '
 
 test_done
