"git read-tree" checks the existence of the blobs referenced by the
given tree, but does not bulk prefetch them. Add a bulk prefetch.
The lack of prefetch here was noticed at $DAYJOB during a merge
involving some specific commits, but I couldn't find a minimal merge
that didn't also trigger the prefetch in check_updates() in
unpack-trees.c (and in all these cases, the lack of prefetch in
cache-tree.c didn't matter because all the relevant blobs would have
already been prefetched by then). This is why I used read-tree here to
exercise this code path.
Signed-off-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
---
cache-tree.c | 11 ++++++++--
t/t1022-read-tree-partial-clone.sh | 33 ++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+), 2 deletions(-)
create mode 100755 t/t1022-read-tree-partial-clone.sh
diff --git a/cache-tree.c b/cache-tree.c
index 45e58666af..9ba2c7c6b2 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -237,6 +237,11 @@ int cache_tree_fully_valid(struct cache_tree *it)
return 1;
}
+static int must_check_existence(const struct cache_entry *ce)
+{
+ return !(has_promisor_remote() && ce_skip_worktree(ce));
+}
+
static int update_one(struct cache_tree *it,
struct cache_entry **cache,
int entries,
@@ -378,8 +383,7 @@ static int update_one(struct cache_tree *it,
}
ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
- (has_promisor_remote() &&
- ce_skip_worktree(ce));
+ !must_check_existence(ce);
if (is_null_oid(oid) ||
(!ce_missing_ok && !has_object_file(oid))) {
strbuf_release(&buffer);
@@ -466,6 +470,9 @@ int cache_tree_update(struct index_state *istate, int flags)
if (!istate->cache_tree)
istate->cache_tree = cache_tree();
+ if (!(flags & WRITE_TREE_MISSING_OK) && has_promisor_remote())
+ prefetch_cache_entries(istate, must_check_existence);
+
trace_performance_enter();
trace2_region_enter("cache_tree", "update", the_repository);
i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
diff --git a/t/t1022-read-tree-partial-clone.sh b/t/t1022-read-tree-partial-clone.sh
new file mode 100755
index 0000000000..a763e27c7d
--- /dev/null
+++ b/t/t1022-read-tree-partial-clone.sh
@@ -0,0 +1,33 @@
+#!/bin/sh
+
+test_description='git read-tree in partial clones'
+
+TEST_NO_CREATE_REPO=1
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+test_expect_success 'read-tree in partial clone prefetches in one batch' '
+ test_when_finished "rm -rf server client trace" &&
+
+ git init server &&
+ echo foo >server/one &&
+ echo bar >server/two &&
+ git -C server add one two &&
+ git -C server commit -m "initial commit" &&
+ TREE=$(git -C server rev-parse HEAD^{tree}) &&
+
+ git -C server config uploadpack.allowfilter 1 &&
+ git -C server config uploadpack.allowanysha1inwant 1 &&
+ git clone --bare --filter=blob:none "file://$(pwd)/server" client &&
+ GIT_TRACE_PACKET="$(pwd)/trace" git -C client read-tree $TREE &&
+
+ # "done" marks the end of negotiation (once per fetch). Expect that
+ # only one fetch occurs.
+ grep "fetch> done" trace >donelines &&
+ test_line_count = 1 donelines
+'
+
+test_done
--
2.32.0.432.gabb21c7263-goog
