name-hash: add perf test for lazy_init_name_hash

Created t/perf/p0004-lazy-init-name-hash.sh test
to demonstrate correctness and performance gains
with the multithreaded version of lazy_init_name_hash().

Signed-off-by: Jeff Hostetler <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jeffhostetler

t/perf/p0004-lazy-init-name-hash.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+test_description='Tests multi-threaded lazy_init_name_hash'
+. ./perf-lib.sh
+
+test_perf_large_repo
+test_checkout_worktree
+
+test_expect_success 'verify both methods build the same hashmaps' '
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --single | sort >out.single &&
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --multi  | sort >out.multi  &&
+	test_cmp out.single out.multi
+'
+
+test_expect_success 'multithreaded should be faster' '
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --perf >out.perf
+'
+
+test_done