Merge branch 'jh/memihash-opt'

The name-hash used for detecting paths that are different only in
cases (which matter on case insensitive filesystems) has been
optimized to take advantage of multi-threading when it makes sense.

* jh/memihash-opt:
  name-hash: add test-lazy-init-name-hash to .gitignore
  name-hash: add perf test for lazy_init_name_hash
  name-hash: add test-lazy-init-name-hash
  name-hash: perf improvement for lazy_init_name_hash
  hashmap: document memihash_cont, hashmap_disallow_rehash api
  hashmap: add disallow_rehash setting
  hashmap: allow memihash computation to be continued
  name-hash: specify initial size for istate.dir_hash table

1 files changed, 19 insertions, 0 deletions

diff --git a/t/perf/p0004-lazy-init-name-hash.sh b/t/perf/p0004-lazy-init-name-hash.sh
new file mode 100644
index 0000000000..5afa8c8df3
--- /dev/null
+++ b/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