object-file: move loose object cache into loose source

Our loose objects use a cache that (optionally) stores all objects for
each of the opened sharding directories. This cache is located in the
`struct odb_source`, but now that we have `struct odb_source_loose` it
makes sense to move it into the latter structure so that all state that
relates to loose objects is entirely self-contained.

Do so. While at it, rename corresponding functions to have a prefix that
relates to `struct odb_source_loose`.

Note that despite this prefix, the functions still accept a `struct
odb_source` as input. This is done intentionally: once we introduce
pluggable object databases, we will continue to accept this struct but
then do a cast inside these functions to `struct odb_source_loose`. This
design is similar to how we do it for our ref backends.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 16 deletions

diff --git a/object-file.c b/object-file.c
index cd6aa561fa..fef00d6d3d 100644
--- a/object-file.c
+++ b/object-file.c
@@ -223,7 +223,7 @@ static int quick_has_loose(struct repository *r,
 
 	odb_prepare_alternates(r->objects);
 	for (source = r->objects->sources; source; source = source->next) {
-		if (oidtree_contains(odb_loose_cache(source, oid), oid))
+		if (oidtree_contains(odb_source_loose_cache(source, oid), oid))
 			return 1;
 	}
 	return 0;
@@ -1802,44 +1802,44 @@ static int append_loose_object(const struct object_id *oid,
 	return 0;
 }
 
-struct oidtree *odb_loose_cache(struct odb_source *source,
-				const struct object_id *oid)
+struct oidtree *odb_source_loose_cache(struct odb_source *source,
+				       const struct object_id *oid)
 {
 	int subdir_nr = oid->hash[0];
 	struct strbuf buf = STRBUF_INIT;
-	size_t word_bits = bitsizeof(source->loose_objects_subdir_seen[0]);
+	size_t word_bits = bitsizeof(source->loose->subdir_seen[0]);
 	size_t word_index = subdir_nr / word_bits;
 	size_t mask = (size_t)1u << (subdir_nr % word_bits);
 	uint32_t *bitmap;
 
 	if (subdir_nr < 0 ||
-	    (size_t) subdir_nr >= bitsizeof(source->loose_objects_subdir_seen))
+	    (size_t) subdir_nr >= bitsizeof(source->loose->subdir_seen))
 		BUG("subdir_nr out of range");
 
-	bitmap = &source->loose_objects_subdir_seen[word_index];
+	bitmap = &source->loose->subdir_seen[word_index];
 	if (*bitmap & mask)
-		return source->loose_objects_cache;
-	if (!source->loose_objects_cache) {
-		ALLOC_ARRAY(source->loose_objects_cache, 1);
-		oidtree_init(source->loose_objects_cache);
+		return source->loose->cache;
+	if (!source->loose->cache) {
+		ALLOC_ARRAY(source->loose->cache, 1);
+		oidtree_init(source->loose->cache);
 	}
 	strbuf_addstr(&buf, source->path);
 	for_each_file_in_obj_subdir(subdir_nr, &buf,
 				    source->odb->repo->hash_algo,
 				    append_loose_object,
 				    NULL, NULL,
-				    source->loose_objects_cache);
+				    source->loose->cache);
 	*bitmap |= mask;
 	strbuf_release(&buf);
-	return source->loose_objects_cache;
+	return source->loose->cache;
 }
 
 void odb_clear_loose_cache(struct odb_source *source)
 {
-	oidtree_clear(source->loose_objects_cache);
-	FREE_AND_NULL(source->loose_objects_cache);
-	memset(&source->loose_objects_subdir_seen, 0,
-	       sizeof(source->loose_objects_subdir_seen));
+	oidtree_clear(source->loose->cache);
+	FREE_AND_NULL(source->loose->cache);
+	memset(&source->loose->subdir_seen, 0,
+	       sizeof(source->loose->subdir_seen));
 }
 
 static int check_stream_oid(git_zstream *stream,
@@ -2006,5 +2006,8 @@ struct odb_source_loose *odb_source_loose_new(struct odb_source *source)
 
 void odb_source_loose_free(struct odb_source_loose *loose)
 {
+	if (!loose)
+		return;
+	odb_clear_loose_cache(loose->source);
 	free(loose);
 }