[PATCH v3 1/6] commit-graph: refactor preparing commit graph

[Jonathan Tan]

Two functions in the code (1) check if the repository is configured for
commit graphs, (2) call prepare_commit_graph(), and (3) check if the
graph exists. Move (1) and (3) into prepare_commit_graph(), reducing
duplication of code.

Signed-off-by: Jonathan Tan <jonathanta...@google.com>
---
 commit-graph.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/commit-graph.c b/commit-graph.c
index 41a0133ff7..1ea701ed69 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -200,15 +200,25 @@ static void prepare_commit_graph_one(const char *obj_dir)
 }
 
 static int prepare_commit_graph_run_once = 0;
-static void prepare_commit_graph(void)
+
+/*
+ * Return 1 if commit_graph is non-NULL, and 0 otherwise.
+ *
+ * On the first invocation, this function attemps to load the commit
+ * graph if the_repository is configured to have one.
+ */
+static int prepare_commit_graph(void)
 {
        struct alternate_object_database *alt;
        char *obj_dir;
 
        if (prepare_commit_graph_run_once)
-               return;
+               return !!commit_graph;
        prepare_commit_graph_run_once = 1;
 
+       if (!core_commit_graph)
+               return 0;
+
        obj_dir = get_object_directory();
        prepare_commit_graph_one(obj_dir);
        prepare_alt_odb(the_repository);
@@ -216,6 +226,7 @@ static void prepare_commit_graph(void)
             !commit_graph && alt;
             alt = alt->next)
                prepare_commit_graph_one(alt->path);
+       return !!commit_graph;
 }
 
 static void close_commit_graph(void)
@@ -337,22 +348,17 @@ static int parse_commit_in_graph_one(struct commit_graph 
*g, struct commit *item
 
 int parse_commit_in_graph(struct commit *item)
 {
-       if (!core_commit_graph)
+       if (!prepare_commit_graph())
                return 0;
-
-       prepare_commit_graph();
-       if (commit_graph)
-               return parse_commit_in_graph_one(commit_graph, item);
-       return 0;
+       return parse_commit_in_graph_one(commit_graph, item);
 }
 
 void load_commit_graph_info(struct commit *item)
 {
        uint32_t pos;
-       if (!core_commit_graph)
+       if (!prepare_commit_graph())
                return;
-       prepare_commit_graph();
-       if (commit_graph && find_commit_in_graph(item, commit_graph, &pos))
+       if (find_commit_in_graph(item, commit_graph, &pos))
                fill_commit_graph_info(item, commit_graph, pos);
 }
 
-- 
2.18.0.203.gfac676dfb9-goog