When running a command like "git show" or "git diff" in a partial clone, batch all missing blobs to be fetched as one request.
This is similar to c0c578b33c ("unpack-trees: batch fetching of missing blobs", 2017-12-08), but for another command.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- Here's an improvement for those having partial clones.
I couldn't find a good place to place the test (a place that checks how diff interfaces with the object store would be ideal), so I created a new one. Let me know if there's a better place to put it. --- diff.c | 27 +++++++++++++ t/t4067-diff-partial-clone.sh | 76 +++++++++++++++++++++++++++++++++++ 2 files changed, 103 insertions(+) create mode 100755 t/t4067-diff-partial-clone.sh
Show changes to 2 files +103 −0
diff.c, t/t4067-diff-partial-clone.sh
diff --git a/diff.c b/diff.c index ec5c095199..0e08d05b14 100644 --- a/diff.c +++ b/diff.c @@ -25,6 +25,7 @@ #include "packfile.h" #include "parse-options.h" #include "help.h" +#include "fetch-object.h" #ifdef NO_FAST_WORKING_DIRECTORY #define FAST_WORKING_DIRECTORY 0 @@ -6067,6 +6068,32 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o) if (o->color_moved) o->emitted_symbols = &esm; + if (repository_format_partial_clone) { + /* + * Prefetch the diff pairs that are about to be flushed. + */ + struct oid_array to_fetch = OID_ARRAY_INIT; + int fetch_if_missing_store = fetch_if_missing; + + fetch_if_missing = 0; + for (i = 0; i < q->nr; i++) { + struct diff_filepair *p = q->queue[i]; + if (!check_pair_status(p)) + continue; + if (p->one && p->one->oid_valid && + !has_object_file(&p->one->oid)) + oid_array_append(&to_fetch, &p->one->oid); + if (p->two && p->two->oid_valid && + !has_object_file(&p->two->oid)) + oid_array_append(&to_fetch, &p->two->oid); + } + if (to_fetch.nr) + fetch_objects(repository_format_partial_clone, + to_fetch.oid, to_fetch.nr); + fetch_if_missing = fetch_if_missing_store; + oid_array_clear(&to_fetch); + } + for (i = 0; i < q->nr; i++) { struct diff_filepair *p = q->queue[i]; if (check_pair_status(p)) diff --git a/t/t4067-diff-partial-clone.sh b/t/t4067-diff-partial-clone.sh new file mode 100755 index 0000000000..38f03be114 --- /dev/null +++ b/t/t4067-diff-partial-clone.sh @@ -0,0 +1,76 @@ +#!/bin/sh + +test_description='behavior of diff when reading objects in a partial clone' + +. ./test-lib.sh + +test_expect_success 'git show batches blobs' ' + test_create_repo server && + echo a >server/a && + echo b >server/b && + git -C server add a b && + git -C server commit -m x && + + test_config -C server uploadpack.allowfilter 1 && + test_config -C server uploadpack.allowanysha1inwant 1 && + git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client && + + # Ensure that there is exactly 1 negotiation by checking that there is + # only 1 "done" line sent. ("done" marks the end of negotiation.) + GIT_TRACE_PACKET="$(pwd)/trace" git -C client show HEAD && + grep "git> done" trace >done_lines && + test_line_count = 1 done_lines +' + +test_expect_success 'diff batches blobs' ' + rm -rf server client trace && + + test_create_repo server && + echo a >server/a && + echo b >server/b && + git -C server add a b && + git -C server commit -m x && + echo c >server/c && + echo d >server/d && + git -C server add c d && + git -C server commit -m x && + + test_config -C server uploadpack.allowfilter 1 && + test_config -C server uploadpack.allowanysha1inwant 1 && + git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client && + + # Ensure that there is exactly 1 negotiation by checking that there is + # only 1 "done" line sent. ("done" marks the end of negotiation.) + GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff HEAD^ HEAD && + grep "git> done" trace >done_lines && + test_line_count = 1 done_lines +' + +test_expect_success 'diff skips same-OID blobs' ' + rm -rf server client trace && + + test_create_repo server && + echo a >server/a && + echo b >server/b && + git -C server add a b && + git -C server commit -m x && + echo another-a >server/a && + git -C server add a && + git -C server commit -m x && + + test_config -C server uploadpack.allowfilter 1 && + test_config -C server uploadpack.allowanysha1inwant 1 && + git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client && + + echo a | git hash-object --stdin >hash-old-a && + echo another-a | git hash-object --stdin >hash-new-a && + echo b | git hash-object --stdin >hash-b && + + # Ensure that only a and another-a are fetched. + GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff HEAD^ HEAD && + grep "want $(cat hash-old-a)" trace && + grep "want $(cat hash-new-a)" trace && + ! grep "want $(cat hash-b)" trace +' + +test_done
-- 2.21.0.155.ge902e9bcae.dirty
