Re: [PATCH v3 4/4] revision: avoid hitting packfiles when commits are in commit-graph
From: Junio C Hamano <hidden>
Date: 2021-08-02 20:01:08
Patrick Steinhardt [off-list ref] writes:
quoted hunk
diff --git a/commit-graph.c b/commit-graph.c index 3860a0d847..a81d5cebc0 100644 --- a/commit-graph.c +++ b/commit-graph.c@@ -864,6 +864,48 @@ static int fill_commit_in_graph(struct repository *r, return 1; }
Describe return-value here. 0 for not-found, !0 for found?
+static int find_object_id_in_graph(const struct object_id *id, struct commit_graph *g, uint32_t *pos)
+{
+ struct commit_graph *cur_g = g;
+ uint32_t lex_index;
+
+ while (cur_g && !bsearch_graph(cur_g, (struct object_id *)id, &lex_index))
+ cur_g = cur_g->base_graph;
+
+ if (cur_g) {
+ *pos = lex_index + cur_g->num_commits_in_base;
+ return 1;
+ }
+
+ return 0;
+}Likewise, or as this is public, perhaps in commit-graph.h next to its declaration.
+int find_object_in_graph(struct repository *repo, struct object *object)
+{
+ struct commit *commit;
+ uint32_t pos;
+
+ if (object->parsed) {
+ if (object->type != OBJ_COMMIT)
+ return -1;
+ return 0;
This is puzzling---at least it is not consistent with what the
function name says ("please say if you find _this_ object in the
commit-graph file"---if that is not what this function does, it
needs a comment before the implementation).
The caller had object and we has already been parsed. If the
function were "with help from commit-graph, please tell me if you
can positively say this is a commit", the above is understandable.
If we know positively that it is not commit, we say "no, it is not a
commit" (which may be suboptimal---if the caller falls back to
another codepath, the object will still not be a commit) and if we
know it is a commit, we can say "yes, it definitely is a commit" and
the caller can stop there.
I guess my only problem with this function is that its name and what
it does does not align. If the caller uses it for the real purpose
of the function I guessed, then the logic itself may be OK.
+ } + + if (!repo->objects->commit_graph) + return -1;
There is no commit-graph, then we decline to make a decision, which makes sense.
+ if (!find_object_id_in_graph(&object->oid, repo->objects->commit_graph, &pos)) + return -1;
If it does not exist in the graph, we cannot tell, either.
quoted hunk
+ commit = object_as_type(object, OBJ_COMMIT, 1); + if (!commit) + return -1; + if (!fill_commit_in_graph(repo, commit, repo->objects->commit_graph, pos)) + return -1; + + return 0; +} + static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos) { uint32_t graph_pos = commit_graph_position(item);@@ -871,18 +913,7 @@ static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uin *pos = graph_pos; return 1; } else { - struct commit_graph *cur_g = g; - uint32_t lex_index; - - while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index)) - cur_g = cur_g->base_graph; - - if (cur_g) { - *pos = lex_index + cur_g->num_commits_in_base; - return 1; - } - - return 0; + return find_object_id_in_graph(&item->object.oid, g, pos);
And I think this one is a op-op refactoring that does not change the behaviour of find_commit_in_graph()? It might be easier if done in a separate preparatory step, but it is small enough.
quoted hunk
diff --git a/commit-graph.h b/commit-graph.h index 96c24fb577..f373fab4c0 100644 --- a/commit-graph.h +++ b/commit-graph.h@@ -139,6 +139,8 @@ int write_commit_graph(struct object_directory *odb, enum commit_graph_write_flags flags, const struct commit_graph_opts *opts); +int find_object_in_graph(struct repository *repo, struct object *object); + #define COMMIT_GRAPH_VERIFY_SHALLOW (1 << 0) int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);diff --git a/revision.c b/revision.c index 671b6d6513..c3f9cf2998 100644 --- a/revision.c +++ b/revision.c@@ -362,10 +362,12 @@ static struct object *get_reference(struct rev_info *revs, const char *name, struct object *object = lookup_unknown_object(revs->repo, oid); if (object->type == OBJ_NONE) { - int type = oid_object_info(revs->repo, oid, NULL); - if (type < 0 || !object_as_type(object, type, 1)) { - object = NULL; - goto out; + if (find_object_in_graph(revs->repo, object) < 0) { + int type = oid_object_info(revs->repo, oid, NULL); + if (type < 0 || !object_as_type(object, type, 1)) { + object = NULL; + goto out; + } } }