fetch: remove fetch_if_missing=0
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> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan committed
Nov 5, 2019 at 10:56 UTC
6462d5eb9a5b23ab9cff4e3c92ff930600562d8f
3 files changed
+74
-4
builtin/fetch.c
+2
-3
@@ -1074,7 +1074,8 @@ static int check_exist_and_connected(struct ref *ref_map)
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* we need all direct targets to exist.
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*/
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for (r = rm; r; r = r->next) {
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- if (!has_object_file(&r->old_oid))
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+ if (!has_object_file_with_flags(&r->old_oid,
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+ OBJECT_INFO_SKIP_FETCH_OBJECT))
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return -1;
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}
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@@ -1822,8 +1823,6 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
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}
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}
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- fetch_if_missing = 0;
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-
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if (remote) {
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if (filter_options.choice || has_promisor_remote())
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fetch_one_setup_partial(remote);
fetch-pack.c
+2
-1
@@ -673,7 +673,8 @@ static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
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struct object *o;
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if (!has_object_file_with_flags(&ref->old_oid,
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- OBJECT_INFO_QUICK))
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+ OBJECT_INFO_QUICK |
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+ OBJECT_INFO_SKIP_FETCH_OBJECT))
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continue;
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o = parse_object(the_repository, &ref->old_oid);
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if (!o)
t/t5616-partial-clone.sh
+70
@@ -296,6 +296,76 @@ test_expect_success 'partial clone with unresolvable sparse filter fails cleanly
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test_i18ngrep "unable to parse sparse filter data in" err
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'
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+setup_triangle () {
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+ rm -rf big-blob.txt server client promisor-remote &&
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+
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+ printf "line %d\n" $(test_seq 1 100) >big-blob.txt &&
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+
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+ # Create a server with 2 commits: a commit with a big blob and a child
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+ # commit with an incremental change. Also, create a partial clone
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+ # client that only contains the first commit.
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+ git init server &&
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+ git -C server config --local uploadpack.allowfilter 1 &&
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+ cp big-blob.txt server &&
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+ git -C server add big-blob.txt &&
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+ git -C server commit -m "initial" &&
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+ git clone --bare --filter=tree:0 "file://$(pwd)/server" client &&
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+ echo another line >>server/big-blob.txt &&
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+ git -C server commit -am "append line to big blob" &&
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+
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+ # Create a promisor remote that only contains the blob from the first
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+ # commit, and set it as the promisor remote of client. Thus, whenever
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+ # the client lazy fetches, the lazy fetch will succeed only if it is
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+ # for this blob.
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+ git init promisor-remote &&
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+ test_commit -C promisor-remote one && # so that ref advertisement is not empty
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+ git -C promisor-remote config --local uploadpack.allowanysha1inwant 1 &&
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+ git -C promisor-remote hash-object -w --stdin <big-blob.txt &&
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+ git -C client remote set-url origin "file://$(pwd)/promisor-remote"
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+}
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+
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+# NEEDSWORK: The tests beginning with "fetch lazy-fetches" below only
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+# test that "fetch" avoid fetching trees and blobs, but not commits or
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+# tags. Revisit this if Git is ever taught to support partial clones
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+# with commits and/or tags filtered out.
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+
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+test_expect_success 'fetch lazy-fetches only to resolve deltas' '
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+ setup_triangle &&
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+
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+ # Exercise to make sure it works. Git will not fetch anything from the
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+ # promisor remote other than for the big blob (because it needs to
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+ # resolve the delta).
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+ GIT_TRACE_PACKET="$(pwd)/trace" git -C client \
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+ fetch "file://$(pwd)/server" master &&
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+
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+ # Verify the assumption that the client needed to fetch the delta base
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+ # to resolve the delta.
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+ git hash-object big-blob.txt >hash &&
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+ grep "want $(cat hash)" trace
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+'
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+
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+test_expect_success 'fetch lazy-fetches only to resolve deltas, protocol v2' '
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+ setup_triangle &&
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+
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+ git -C server config --local protocol.version 2 &&
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+ git -C client config --local protocol.version 2 &&
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+ git -C promisor-remote config --local protocol.version 2 &&
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+
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+ # Exercise to make sure it works. Git will not fetch anything from the
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+ # promisor remote other than for the big blob (because it needs to
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+ # resolve the delta).
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+ GIT_TRACE_PACKET="$(pwd)/trace" git -C client \
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+ fetch "file://$(pwd)/server" master &&
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+
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+ # Verify that protocol version 2 was used.
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+ grep "fetch< version 2" trace &&
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+
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+ # Verify the assumption that the client needed to fetch the delta base
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+ # to resolve the delta.
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+ git hash-object big-blob.txt >hash &&
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+ grep "want $(cat hash)" trace
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+'
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+
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. "$TEST_DIRECTORY"/lib-httpd.sh
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start_httpd
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