The struct member generation refers to "generation number" (or more
broadly, a reachablity index value) used by commit-graph to reduce time
taken to walk commits. However, generation is not useful in other
contexts and bloats the struct.
Let's move it to a commit-slab and shrink the struct by four bytes.
Signed-off-by: Abhishek Kumar <abhishekkumar8222@xxxxxxxxx>
---
commit-graph.c | 27 +++++++++++++++++++++++++++
commit-graph.h | 5 +++++
commit.h | 3 ---
3 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/commit-graph.c b/commit-graph.c
index e3420ddcbf..63f419048d 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -87,6 +87,33 @@ static int commit_pos_cmp(const void *va, const void *vb)
commit_pos_at(&commit_pos, b);
}
+define_commit_slab(generation_slab, uint32_t);
+static struct generation_slab generation_slab = COMMIT_SLAB_INIT(1, generation_slab);
+
+uint32_t generation(const struct commit *c)
+{
+ uint32_t *gen = generation_slab_peek(&generation_slab, c);
+
+ return gen ? *gen : GENERATION_NUMBER_INFINITY;
+}
+
+static void set_generation(const struct commit *c, const uint32_t generation)
+{
+ unsigned int i = generation_slab.slab_count;
+ uint32_t *gen = generation_slab_at(&generation_slab, c);
+
+ /*
+ * commit-slab initializes with zero, overwrite this with
+ * GENERATION_NUMBER_INFINITY
+ */
+ for (; i < generation_slab.slab_count; ++i) {
+ memset(generation_slab.slab[i], GENERATION_NUMBER_INFINITY,
+ generation_slab.slab_size * sizeof(uint32_t));
+ }
+
+ *gen = generation;
+}
+
static int commit_gen_cmp(const void *va, const void *vb)
{
const struct commit *a = *(const struct commit **)va;
diff --git a/commit-graph.h b/commit-graph.h
index 4212766a4f..653bd041ad 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -8,6 +8,10 @@
#include "object-store.h"
#include "oidset.h"
+#define GENERATION_NUMBER_INFINITY 0xFFFFFFFF
+#define GENERATION_NUMBER_MAX 0x3FFFFFFF
+#define GENERATION_NUMBER_ZERO 0
+
#define GIT_TEST_COMMIT_GRAPH "GIT_TEST_COMMIT_GRAPH"
#define GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD"
#define GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS "GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS"
@@ -137,4 +141,5 @@ void free_commit_graph(struct commit_graph *);
*/
void disable_commit_graph(struct repository *r);
+uint32_t generation(const struct commit *c);
#endif
diff --git a/commit.h b/commit.h
index 1b2dea5d85..cc610400d5 100644
--- a/commit.h
+++ b/commit.h
@@ -11,9 +11,6 @@
#include "commit-slab.h"
#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
-#define GENERATION_NUMBER_INFINITY 0xFFFFFFFF
-#define GENERATION_NUMBER_MAX 0x3FFFFFFF
-#define GENERATION_NUMBER_ZERO 0
struct commit_list {
struct commit *item;
--
2.27.0
