diff mbox series

[v2,2/2] t7063: mtime-mangling instead of delays in untracked cache testing

Message ID 3e3c9c7faace505958aa01ff82bef5fad3204c67.1646127910.git.gitgitgadget@gmail.com (mailing list archive)
State Superseded
Headers show
Series Reduce explicit sleep calls in t7063 untracked cache tests | expand

Commit Message

Tao Klerks March 1, 2022, 9:45 a.m. UTC 
From: Tao Klerks <tao@klerks.biz>

The untracked cache test uses an avoid_racy function to deal with
an mtime-resolution challenge in testing: If an untracked cache
entry's mtime falls in the same second as the mtime of the index
the untracked cache was stored in, then it cannot be trusted.

Explicitly delaying tests is a simple effective strategy to
avoid these issues, but should be avoided where possible.

Switch from a delay-based strategy to instead backdating
all file changes using test-tool chmtime, where that is an
option, to shave 9 seconds off the test run time.

Don't update test cases that delay for other reasons, for now at
least (4 seconds).

Signed-off-by: Tao Klerks <tao@klerks.biz>
---
 t/t7063-status-untracked-cache.sh | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

Comments

Junio C Hamano March 1, 2022, 6:03 p.m. UTC | #1 
"Tao Klerks via GitGitGadget" <gitgitgadget@gmail.com> writes:

> +chmtime_worktree_root () {
> +	# chmtime doesnt handle relative paths on windows, so need
> +	# to "hardcode" a reference to the worktree folder name.
> +	test-tool -C .. chmtime $1 worktree
> +}
> +

Enclose $1 in a pair of double-quotes to help readers.  They do not
have to wonder if the caller is interested in (or has to worry
about) triggering word splitting at $IFS if you did so.

>  avoid_racy() {
>  	sleep 1
>  }
> @@ -90,6 +96,9 @@ test_expect_success 'setup' '
>  	cd worktree &&
>  	mkdir done dtwo dthree &&
>  	touch one two three done/one dtwo/two dthree/three &&
> +	test-tool chmtime =-300 one two three done/one dtwo/two dthree/three &&
> +	test-tool chmtime =-300 done dtwo dthree &&
> +	chmtime_worktree_root =-300 &&

I am wondering if it is better to spelling it out like this:

	test-tool -C.. chmtime =-300 worktree &&

instead of hiding the fact that "../worktree" is being touched
behind a one-line helper.  Being able to explicitly write "worktree"
in the context that this particular code path uses the "worktree"
directory is a big plus, but at the same time, bypassing the helper
makes it unclear why we just don't chmtime "../worktree", and will
strongly tempt future developers into breaking it, so, I dunno.

What's the reason why utime() works only on a path in the current
directory and cannot take "../worktree" again?  If we cannot solve
that, I guess an extra helper with a big comment, like we see in
this patch, would be the least bad solution.

Thanks.
Tao Klerks March 1, 2022, 10:13 p.m. UTC | #2 
On Tue, Mar 1, 2022 at 7:03 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> "Tao Klerks via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > +chmtime_worktree_root () {
> > +     # chmtime doesnt handle relative paths on windows, so need
> > +     # to "hardcode" a reference to the worktree folder name.
> > +     test-tool -C .. chmtime $1 worktree
> > +}
> > +
>
> Enclose $1 in a pair of double-quotes to help readers.  They do not
> have to wonder if the caller is interested in (or has to worry
> about) triggering word splitting at $IFS if you did so.

Absolutely, thx.

>
> >  avoid_racy() {
> >       sleep 1
> >  }
> > @@ -90,6 +96,9 @@ test_expect_success 'setup' '
> >       cd worktree &&
> >       mkdir done dtwo dthree &&
> >       touch one two three done/one dtwo/two dthree/three &&
> > +     test-tool chmtime =-300 one two three done/one dtwo/two dthree/three &&
> > +     test-tool chmtime =-300 done dtwo dthree &&
> > +     chmtime_worktree_root =-300 &&
>
> I am wondering if it is better to spelling it out like this:
>
>         test-tool -C.. chmtime =-300 worktree &&
>
> instead of hiding the fact that "../worktree" is being touched
> behind a one-line helper.  Being able to explicitly write "worktree"
> in the context that this particular code path uses the "worktree"
> directory is a big plus, but at the same time, bypassing the helper
> makes it unclear why we just don't chmtime "../worktree", and will
> strongly tempt future developers into breaking it, so, I dunno.
>
> What's the reason why utime() works only on a path in the current
> directory and cannot take "../worktree" again? If we cannot solve
> that, I guess an extra helper with a big comment, like we see in
> this patch, would be the least bad solution.
>

Heh. It didn't work, in my initial tests. Now it does. It turns out I was
initially getting the directory handle with
"FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES", and
everything worked except modifying the current folder via a relative
path expression, which yielded a "Permission denied" error. I
worked around it by explicitly changing the current directory...

Then I realized FILE_WRITE_DATA wasn't necessary (but didn't
connect the dots). Then you noted the "-C .." arg to test-tool
(and I still didn't connect the dots).

The problem was never relative paths, but rather trying to get a
writable handle to the current directory. The only reason "-C .."
worked was that I already stopped trying to get a writable handle.

I have no idea what it means to get a writable handle to a
directory, but apparently you can't do it for your current
directory. Now I know.

Thanks for the nudge, this is all clean now.
diff mbox series

Patch

diff --git a/t/t7063-status-untracked-cache.sh b/t/t7063-status-untracked-cache.sh
index a0c123b0a77..eae57dc78a6 100755
--- a/t/t7063-status-untracked-cache.sh
+++ b/t/t7063-status-untracked-cache.sh
@@ -24,6 +24,12 @@  sync_mtime () {
 	find . -type d -exec ls -ld {} + >/dev/null
 }
 
+chmtime_worktree_root () {
+	# chmtime doesnt handle relative paths on windows, so need
+	# to "hardcode" a reference to the worktree folder name.
+	test-tool -C .. chmtime $1 worktree
+}
+
 avoid_racy() {
 	sleep 1
 }
@@ -90,6 +96,9 @@  test_expect_success 'setup' '
 	cd worktree &&
 	mkdir done dtwo dthree &&
 	touch one two three done/one dtwo/two dthree/three &&
+	test-tool chmtime =-300 one two three done/one dtwo/two dthree/three &&
+	test-tool chmtime =-300 done dtwo dthree &&
+	chmtime_worktree_root =-300 &&
 	git add one two done/one &&
 	: >.git/info/exclude &&
 	git update-index --untracked-cache &&
@@ -142,7 +151,6 @@  two
 EOF
 
 test_expect_success 'status first time (empty cache)' '
-	avoid_racy &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../actual &&
@@ -166,7 +174,6 @@  test_expect_success 'untracked cache after first status' '
 '
 
 test_expect_success 'status second time (fully populated cache)' '
-	avoid_racy &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../actual &&
@@ -190,8 +197,8 @@  test_expect_success 'untracked cache after second status' '
 '
 
 test_expect_success 'modify in root directory, one dir invalidation' '
-	avoid_racy &&
 	: >four &&
+	test-tool chmtime =-240 four &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../actual &&
@@ -241,7 +248,6 @@  EOF
 '
 
 test_expect_success 'new .gitignore invalidates recursively' '
-	avoid_racy &&
 	echo four >.gitignore &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
@@ -292,7 +298,6 @@  EOF
 '
 
 test_expect_success 'new info/exclude invalidates everything' '
-	avoid_racy &&
 	echo three >>.git/info/exclude &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
@@ -520,14 +525,14 @@  test_expect_success 'create/modify files, some of which are gitignored' '
 	echo three >done/three && # three is gitignored
 	echo four >done/four && # four is gitignored at a higher level
 	echo five >done/five && # five is not gitignored
-	echo test >base && #we need to ensure that the root dir is touched
-	rm base &&
+	test-tool chmtime =-180 done/two done/three done/four done/five done &&
+	# we need to ensure that the root dir is touched (in the past);
+	chmtime_worktree_root =-180 &&
 	sync_mtime
 '
 
 test_expect_success 'test sparse status with untracked cache' '
 	: >../trace.output &&
-	avoid_racy &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../status.actual &&
 	iuc status --porcelain >../status.iuc &&
@@ -570,7 +575,6 @@  EOF
 '
 
 test_expect_success 'test sparse status again with untracked cache' '
-	avoid_racy &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../status.actual &&
@@ -597,11 +601,11 @@  EOF
 test_expect_success 'set up for test of subdir and sparse checkouts' '
 	mkdir done/sub &&
 	mkdir done/sub/sub &&
-	echo "sub" > done/sub/sub/file
+	echo "sub" > done/sub/sub/file &&
+	test-tool chmtime =-120 done/sub/sub/file done/sub/sub done/sub done
 '
 
 test_expect_success 'test sparse status with untracked cache and subdir' '
-	avoid_racy &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../status.actual &&
@@ -651,7 +655,6 @@  EOF
 '
 
 test_expect_success 'test sparse status again with untracked cache and subdir' '
-	avoid_racy &&
 	: >../trace.output &&
 	GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.output" \
 	git status --porcelain >../status.actual &&