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| author |  Jonathan Tan <jonathantanmy@google.com> | 2020-04-07 15:11:43 -0700 |
|---|---|---|
| committer |  Junio C Hamano <gitster@pobox.com> | 2020-04-07 16:09:29 -0700 |
| commit | 95acf11a3dc3d18ec999f4913ec6c6a54545c6b7 (patch) | |
| tree | 3448ee7b27c3a42dfc07931e7eee15441b1b57c8 /t | |
| parent | diff: refactor object read (diff) | |
| download | tgif-95acf11a3dc3d18ec999f4913ec6c6a54545c6b7.tar.xz | |
diff: restrict when prefetching occurs
Commit 7fbbcb21b1 ("diff: batch fetching of missing blobs", 2019-04-08)
optimized "diff" by prefetching blobs in a partial clone, but there are
some cases wherein blobs do not need to be prefetched. In these cases,
any command that uses the diff machinery will unnecessarily fetch blobs.
diffcore_std() may read blobs when it calls the following functions:
(1) diffcore_skip_stat_unmatch() (controlled by the config variable
diff.autorefreshindex)
(2) diffcore_break() and diffcore_merge_broken() (for break-rewrite
detection)
(3) diffcore_rename() (for rename detection)
(4) diffcore_pickaxe() (for detecting addition/deletion of specified
string)
Instead of always prefetching blobs, teach diffcore_skip_stat_unmatch(),
diffcore_break(), and diffcore_rename() to prefetch blobs upon the first
read of a missing object. This covers (1), (2), and (3): to cover the
rest, teach diffcore_std() to prefetch if the output type is one that
includes blob data (and hence blob data will be required later anyway),
or if it knows that (4) will be run.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't')
| -rwxr-xr-x | t/t4067-diff-partial-clone.sh | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/t/t4067-diff-partial-clone.sh b/t/t4067-diff-partial-clone.sh index 4831ad35e6..c1ed1c2fc4 100755 --- a/t/t4067-diff-partial-clone.sh +++ b/t/t4067-diff-partial-clone.sh @@ -131,4 +131,52 @@ test_expect_success 'diff with rename detection batches blobs' ' test_line_count = 1 done_lines ' +test_expect_success 'diff does not fetch anything if inexact rename detection is not needed' ' + test_when_finished "rm -rf server client trace" && + + test_create_repo server && + echo a >server/a && + printf "b\nb\nb\nb\nb\n" >server/b && + git -C server add a b && + git -C server commit -m x && + mv server/b server/c && + git -C server add c && + git -C server commit -a -m x && + + test_config -C server uploadpack.allowfilter 1 && + test_config -C server uploadpack.allowanysha1inwant 1 && + git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client && + + # Ensure no fetches. + GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD && + ! test_path_exists trace +' + +test_expect_success 'diff --break-rewrites fetches only if necessary, and batches blobs if it does' ' + test_when_finished "rm -rf server client trace" && + + test_create_repo server && + echo a >server/a && + printf "b\nb\nb\nb\nb\n" >server/b && + git -C server add a b && + git -C server commit -m x && + printf "c\nc\nc\nc\nc\n" >server/b && + git -C server commit -a -m x && + + test_config -C server uploadpack.allowfilter 1 && + test_config -C server uploadpack.allowanysha1inwant 1 && + git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client && + + # Ensure no fetches. + GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD && + ! test_path_exists trace && + + # But with --break-rewrites, ensure that there is exactly 1 negotiation + # by checking that there is only 1 "done" line sent. ("done" marks the + # end of negotiation.) + GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --break-rewrites --raw -M HEAD^ HEAD && + grep "git> done" trace >done_lines && + test_line_count = 1 done_lines +' + test_done |