From 91de27c54a6ede76b3859bc89f4c387705025f6e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Date: Thu, 11 May 2017 09:41:07 +0000 Subject: [PATCH 1/2] perf: add function to setup a fresh test repo MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- t/perf/README | 1 + t/perf/perf-lib.sh | 19 +++++++++++++++---- 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/t/perf/README b/t/perf/README index 49ea4349be..de2fe15696 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 ab4b8b06ae..b6fc880395 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" } From 62ca75a6b9cb2e51b4eed7c551f13975b440a86c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Date: Thu, 11 May 2017 09:41:08 +0000 Subject: [PATCH 2/2] 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 Reviewed-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- t/perf/p0100-globbing.sh | 43 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100755 t/perf/p0100-globbing.sh diff --git a/t/perf/p0100-globbing.sh b/t/perf/p0100-globbing.sh new file mode 100755 index 0000000000..dd18a9ce2b --- /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