From 91de27c54a6ede76b3859bc89f4c387705025f6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Thu, 11 May 2017 09:41:07 +0000
Subject: perf: add function to setup a fresh test repo
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Content-Type: text/plain; charset=UTF-8
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Add a function to setup a fresh test repo via 'git init' to compliment
the existing functions to copy over a normal & large repo.

Some performance tests don't need any existing repository data at all
to be significant, e.g. tests which stress glob matches against single
pathological revisions or files, which I'm about to add in a
subsequent commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/perf/README b/t/perf/README
index 49ea434..de2fe15 100644
--- a/t/perf/README
+++ b/t/perf/README
@@ -106,6 +106,7 @@ sources perf-lib.sh:
 
 After that you will want to use some of the following:
 
+	test_perf_fresh_repo    # sets up an empty repository
 	test_perf_default_repo  # sets up a "normal" repository
 	test_perf_large_repo    # sets up a "large" repository
 
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index ab4b8b0..b6fc880 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -78,6 +78,10 @@ if test -z "$GIT_PERF_LARGE_REPO"; then
 	GIT_PERF_LARGE_REPO=$TEST_DIRECTORY/..
 fi
 
+test_perf_do_repo_symlink_config_ () {
+	test_have_prereq SYMLINKS || git config core.symlinks false
+}
+
 test_perf_create_repo_from () {
 	test "$#" = 2 ||
 	error "bug in the test script: not 2 parameters to test-create-repo"
@@ -102,15 +106,22 @@ test_perf_create_repo_from () {
 	) &&
 	(
 		cd "$repo" &&
-		"$MODERN_GIT" init -q && {
-			test_have_prereq SYMLINKS ||
-			git config core.symlinks false
-		} &&
+		"$MODERN_GIT" init -q &&
+		test_perf_do_repo_symlink_config_ &&
 		mv .git/hooks .git/hooks-disabled 2>/dev/null
 	) || error "failed to copy repository '$source' to '$repo'"
 }
 
 # call at least one of these to establish an appropriately-sized repository
+test_perf_fresh_repo () {
+	repo="${1:-$TRASH_DIRECTORY}"
+	"$MODERN_GIT" init -q "$repo" &&
+	(
+		cd "$repo" &&
+		test_perf_do_repo_symlink_config_
+	)
+}
+
 test_perf_default_repo () {
 	test_perf_create_repo_from "${1:-$TRASH_DIRECTORY}" "$GIT_PERF_REPO"
 }
-- 
cgit v0.10.2-6-g49f6


From 62ca75a6b9cb2e51b4eed7c551f13975b440a86c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Thu, 11 May 2017 09:41:08 +0000
Subject: perf: add test showing exponential growth in path globbing
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a test showing that runtimes of the wildmatch() function used for
globbing in git grow exponentially in the face of some pathological
globs.

This issue affects both globs matching filenames via e.g. ls-files,
and globs matching refnames via e.g. for-each-ref.

As noted in the test description this is a test to see whether Git
suffers from the issue noted in an article Russ Cox posted today about
common bugs in various glob implementations:
https://research.swtch.com/glob

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/perf/p0100-globbing.sh b/t/perf/p0100-globbing.sh
new file mode 100755
index 0000000..dd18a9c
--- /dev/null
+++ b/t/perf/p0100-globbing.sh
@@ -0,0 +1,43 @@
+#!/bin/sh
+
+test_description="Tests pathological globbing performance
+
+Shows how Git's globbing performance performs when given the sort of
+pathological patterns described in at https://research.swtch.com/glob
+"
+
+. ./perf-lib.sh
+
+test_globs_big='10 25 50 75 100'
+test_globs_small='1 2 3 4 5 6'
+
+test_perf_fresh_repo
+
+test_expect_success 'setup' '
+	for i in $(test_seq 1 100)
+	do
+		printf "a" >>refname &&
+		for j in $(test_seq 1 $i)
+		do
+			printf "a*" >>refglob.$i
+		done &&
+		echo b >>refglob.$i
+	done &&
+	test_commit test $(cat refname).t "" $(cat refname).t
+'
+
+for i in $test_globs_small
+do
+	test_perf "refglob((a*)^nb) against tag (a^100).t; n = $i" '
+		git for-each-ref "refs/tags/$(cat refglob.'$i')b"
+	'
+done
+
+for i in $test_globs_small
+do
+	test_perf "fileglob((a*)^nb) against file (a^100).t; n = $i" '
+		git ls-files "$(cat refglob.'$i')b"
+	'
+done
+
+test_done
-- 
cgit v0.10.2-6-g49f6