We'll the connectivity check logic for git-receive-pack(1) in the
following commits to make it perform better. As a preparatory step, add
some benchmarks such that we can measure these changes.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 t/perf/p5400-receive-pack.sh | 74 ++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100755 t/perf/p5400-receive-pack.sh

diff --git a/t/perf/p5400-receive-pack.sh b/t/perf/p5400-receive-pack.sh
new file mode 100755
index 0000000000..2b0c89d977
--- /dev/null
+++ b/t/perf/p5400-receive-pack.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+test_description="Tests performance of receive-pack"
+
+. ./perf-lib.sh
+
+test_perf_large_repo
+
+test_expect_success 'setup' '
+	# Create a main branch such that we do not have to rely on any specific
+	# branch to exist in the perf repository.
+	git switch --force-create main &&
+
+	TARGET_REPO_CLONE=$(pwd)/target-clone.git &&
+	git clone --bare --dissociate --branch main "$(pwd)" "$TARGET_REPO_CLONE" &&
+	TARGET_REPO_REFS=$(pwd)/target-refs.git &&
+	git clone --bare --dissociate --branch main "$(pwd)" "$TARGET_REPO_REFS" &&
+	TARGET_REPO_EMPTY=$(pwd)/target-empty.git &&
+	git init --bare "$TARGET_REPO_EMPTY" &&
+
+	# Set up a pre-receive hook such that no refs will ever be changed.
+	# This easily allows multiple perf runs, but still exercises
+	# server-side reference negotiation and checking for consistency.
+	mkdir hooks &&
+	write_script hooks/pre-receive <<-EOF &&
+		#!/bin/sh
+		echo "failed in pre-receive hook"
+		exit 1
+	EOF
+	cat >config <<-EOF &&
+		[core]
+			hooksPath=$(pwd)/hooks
+	EOF
+	GIT_CONFIG_GLOBAL="$(pwd)/config" &&
+	export GIT_CONFIG_GLOBAL &&
+
+	# Create a reference for each commit in the target repository with
+	# extra-refs. While this may be an atypical setup, biggish repositories
+	# easily end up with hundreds of thousands of refs, and this is a good
+	# enough approximation.
+	git -C "$TARGET_REPO_REFS" log --all --format="tformat:create refs/commit/%h %H" |
+		git -C "$TARGET_REPO_REFS" update-ref --stdin &&
+
+	git switch --create updated &&
+	test_commit --no-tag updated
+'
+
+while read name repo
+do
+	refs=("create updated:new")
+
+	# If the target repository is the empty one, then the only thing we can
+	# do is to create a new branch.
+	if test "$repo" != "$TARGET_REPO_EMPTY"
+	then
+		refs+=("update updated:main" "reset main~:main" "delete :main")
+	fi
+
+	while read desc ref
+	do
+		test_expect_success "setup $name $desc" "
+			test_must_fail git push --force '$repo' '$ref' \
+				--receive-pack='tee pack | git receive-pack' 2>err &&
+			grep 'failed in pre-receive hook' err
+		"
+
+		test_perf "receive-pack $name $desc" "
+			git receive-pack '$repo' <pack >negotiation &&
+			grep 'pre-receive hook declined' negotiation
+		"
+	done < <(printf "%s\n" "${refs[@]}")
+done < <(printf "%s\n" "clone $TARGET_REPO_CLONE" "extrarefs $TARGET_REPO_REFS" "empty $TARGET_REPO_EMPTY")
+
+test_done
-- 
2.31.1