[PATCH v2] upload-pack: do not lazy-fetch "have" objects
- From
- Jonathan Tan <jonathantanmy@google.com>
- Date
- Jul 16, 2020, 18:09 UTC
- Message-ID
- <20200716180950.2852753-1-jonathantanmy@google.com>
- In-Reply-To
- <xmqqk0z3gy5y.fsf@gitster.c.googlers.com>
When upload-pack receives a request containing "have" hashes, it (among other things) checks if the served repository has the corresponding objects. However, it does not do so with the OBJECT_INFO_SKIP_FETCH_OBJECT flag, so if serving a partial clone, a lazy fetch will be triggered first.
This was discovered at $DAYJOB when a user fetched from a partial clone (into another partial clone - although this would also happen if the repo to be fetched into is not a partial clone).
Therefore, whenever "have" hashes are checked for existence, pass the OBJECT_INFO_SKIP_FETCH_OBJECT flag. Also add the OBJECT_INFO_QUICK flag to improve performance, as it is typical that such objects do not exist in the serving repo, and the consequences of a false negative are minor (usually, a slightly larger pack sent).
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- Differences from v1: OBJECT_INFO_QUICK is also used wherever OBJECT_INFO_SKIP_FETCH_OBJECT is added.
Using OBJECT_INFO_QUICK makes sense to me, so here's an updated patch. --- t/t5616-partial-clone.sh | 38 ++++++++++++++++++++++++++++++++++++++ upload-pack.c | 6 ++++-- 2 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 8a27452a51..37de0afb02 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -422,6 +422,44 @@ test_expect_success 'single-branch tag following respects partial clone' ' test_must_fail git -C single rev-parse --verify refs/tags/C ' +test_expect_success 'fetch from a partial clone, protocol v0' ' + rm -rf server client trace && + + # Pretend that the server is a partial clone + git init server && + git -C server remote add a_remote "file://$(pwd)/" && + test_config -C server core.repositoryformatversion 1 && + test_config -C server extensions.partialclone a_remote && + test_config -C server protocol.version 0 && + test_commit -C server foo && + + # Fetch from the server + git init client && + test_config -C client protocol.version 0 && + test_commit -C client bar && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch "file://$(pwd)/server" && + ! grep "version 2" trace +' + +test_expect_success 'fetch from a partial clone, protocol v2' ' + rm -rf server client trace && + + # Pretend that the server is a partial clone + git init server && + git -C server remote add a_remote "file://$(pwd)/" && + test_config -C server core.repositoryformatversion 1 && + test_config -C server extensions.partialclone a_remote && + test_config -C server protocol.version 2 && + test_commit -C server foo && + + # Fetch from the server + git init client && + test_config -C client protocol.version 2 && + test_commit -C client bar && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch "file://$(pwd)/server" && + grep "version 2" trace +' + . "$TEST_DIRECTORY"/lib-httpd.sh start_httpd diff --git a/upload-pack.c b/upload-pack.c index 951a2b23aa..8673741070 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -482,7 +482,8 @@ static int got_oid(struct upload_pack_data *data, { if (get_oid_hex(hex, oid)) die("git upload-pack: expected SHA1 object, got '%s'", hex); - if (!has_object_file(oid)) + if (!has_object_file_with_flags(oid, + OBJECT_INFO_QUICK | OBJECT_INFO_SKIP_FETCH_OBJECT)) return -1; return do_got_oid(data, oid); } @@ -1423,7 +1424,8 @@ static int process_haves(struct upload_pack_data *data, struct oid_array *common for (i = 0; i < data->haves.nr; i++) { const struct object_id *oid = &data->haves.oid[i]; - if (!has_object_file(oid)) + if (!has_object_file_with_flags(oid, + OBJECT_INFO_QUICK | OBJECT_INFO_SKIP_FETCH_OBJECT)) continue; oid_array_append(common, oid);
-- 2.27.0.389.gc38d7665816-goog