In fetch_pack() (and all functions it calls), pass OBJECT_INFO_SKIP_FETCH_OBJECT whenever we query an object that could be a tree or blob that we do not want to be lazy-fetched even if it is absent. Thus, the only lazy-fetches occurring for trees and blobs are when resolving deltas.
Thus, we can remove fetch_if_missing=0 from builtin/fetch.c. Remove this, and also add a test ensuring that such objects are not lazy-fetched. (We might be able to remove fetch_if_missing=0 from other places too, but I have limited myself to builtin/fetch.c in this commit because I have not written tests for the other commands yet.)
Note that commits and tags may still be lazy-fetched. I limited myself to objects that could be trees or blobs here because Git does not support creating such commit- and tag-excluding clones yet, and even if such a clone were manually created, Git does not have good support for fetching a single commit (when fetching a commit, it and all its ancestors would be sent).
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- I've verified that this also solves the bug explained in: https://public-inbox.org/git/20191007181825.13463-1-jonathantanmy@google.com/
Quoting what I wrote from there:
Show 5 quoted lines
> (Alternatively, we > could add the equivalent of OBJECT_INFO_SKIP_FETCH_OBJECT to functions > like parse_commit() that are used by files like negotiator/default.c, or > split up commit parsing into object reading - which already has that > flag - and commit parsing.)
This commit adds OBJECT_INFO_SKIP_FETCH_OBJECT to functions, but not the parse_commit() mentioned - as stated above, this commit only handles objects that could be trees or blobs. --- builtin/fetch.c | 5 ++- fetch-pack.c | 3 +- t/t5616-partial-clone.sh | 69 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 73 insertions(+), 4 deletions(-)
Show changes to 3 files +73 −4
builtin/fetch.c, fetch-pack.c, t/t5616-partial-clone.sh
diff --git a/builtin/fetch.c b/builtin/fetch.c index 0c345b5dfe..5ff7367dd7 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -1074,7 +1074,8 @@ static int check_exist_and_connected(struct ref *ref_map) * we need all direct targets to exist. */ for (r = rm; r; r = r->next) { - if (!has_object_file(&r->old_oid)) + if (!has_object_file_with_flags(&r->old_oid, + OBJECT_INFO_SKIP_FETCH_OBJECT)) return -1; } @@ -1755,8 +1756,6 @@ int cmd_fetch(int argc, const char **argv, const char *prefix) packet_trace_identity("fetch"); - fetch_if_missing = 0; - /* Record the command line for the reflog */ strbuf_addstr(&default_rla, "fetch"); for (i = 1; i < argc; i++) diff --git a/fetch-pack.c b/fetch-pack.c index 0130b44112..37178e2d34 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -673,7 +673,8 @@ static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator, struct object *o; if (!has_object_file_with_flags(&ref->old_oid, - OBJECT_INFO_QUICK)) + OBJECT_INFO_QUICK | + OBJECT_INFO_SKIP_FETCH_OBJECT)) continue; o = parse_object(the_repository, &ref->old_oid); if (!o) diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 79f7b65f8c..1081ed2de0 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -296,6 +296,75 @@ test_expect_success 'partial clone with unresolvable sparse filter fails cleanly test_i18ngrep "unable to parse sparse filter data in" err ' +setup_triangle () { + rm -rf big-blob.txt server client promisor-remote && + + touch big-blob.txt && + for i in $(seq 1 100) + do + echo line $i >>big-blob.txt + done && + + # Create a server with 2 commits: a commit with a big blob and a child + # commit with an incremental change. Also, create a partial clone + # client that only contains the first commit. + git init server && + git -C server config --local uploadpack.allowfilter 1 && + cp big-blob.txt server && + git -C server add big-blob.txt && + git -C server commit -m "initial" && + git clone --bare --filter=tree:0 "file://$(pwd)/server" client && + echo another line >>server/big-blob.txt && + git -C server commit -am "append line to big blob" && + + # Create a promisor remote that only contains the blob from the first + # commit, and set it as the promisor remote of client. Thus, whenever + # the client lazy fetches, the lazy fetch will succeed only if it is + # for this blob. + git init promisor-remote && + test_commit -C promisor-remote one && # so that ref advertisement is not empty + git -C promisor-remote config --local uploadpack.allowanysha1inwant 1 && + git -C promisor-remote hash-object -w --stdin <big-blob.txt && + git -C client remote set-url origin "file://$(pwd)/promisor-remote" +} + +test_expect_success 'fetch lazy-fetches only to resolve deltas' ' + setup_triangle && + + # Exercise to make sure it works. Git will not fetch anything from the + # promisor remote other than for the big blob (because it needs to + # resolve the delta). + GIT_TRACE_PACKET="$(pwd)/trace" git -C client \ + fetch "file://$(pwd)/server" master && + + # Verify the assumption that the client needed to fetch the delta base + # to resolve the delta. + git hash-object big-blob.txt >hash && + grep "want $(cat hash)" trace +' + +test_expect_success 'fetch lazy-fetches only to resolve deltas, protocol v2' ' + setup_triangle && + + git -C server config --local protocol.version 2 && + git -C client config --local protocol.version 2 && + git -C promisor-remote config --local protocol.version 2 && + + # Exercise to make sure it works. Git will not fetch anything from the + # promisor remote other than for the big blob (because it needs to + # resolve the delta). + GIT_TRACE_PACKET="$(pwd)/trace" git -C client \ + fetch "file://$(pwd)/server" master && + + # Verify that protocol version 2 was used. + grep "fetch< version 2" trace && + + # Verify the assumption that the client needed to fetch the delta base + # to resolve the delta. + git hash-object big-blob.txt >hash && + grep "want $(cat hash)" trace +' + . "$TEST_DIRECTORY"/lib-httpd.sh start_httpd
-- 2.24.0.rc1.363.gb1bccd3e3d-goog
