Re: [PATCH v3 04/14] commit-graph: implement write_commit_graph()

Derrick Stolee [off-list ref] writes:

+struct packed_oid_list {
+	struct object_id **list;
+	int nr;
+	int alloc;
+};

What is the typical access pattern for this data structure?  If it
is pretty much "allocate and grow as we find more", then a dynamic
array of struct (rather than a dynamic array of pointers to struct)
would be a lot more appropriate.  IOW

	struct packed_oid_list {
		struct object_id *list;
		int nr, alloc;
	};

The version in the posted patch has to pay malloc overhead plus an
extra pointer for each object id in the list; unless you often
replace elements in the list randomly and/or you borrow object ID
field in other existing data structure whose lifetime is longer than
this list by pointing at it, I do not see how the extra indirection
is worth it.