packfile: move packfile store into object source

The packfile store is a member of `struct object_database`, which means
that we have a single store per database. This doesn't really make much
sense though: each source connected to the database has its own set of
packfiles, so there is a conceptual mismatch here. This hasn't really
caused much of a problem in the past, but with the advent of pluggable
object databases this is becoming more of a problem because some of the
sources may not even use packfiles in the first place.

Move the packfile store down by one level from the object database into
the object database source. This ensures that each source now has its
own packfile store, and we can eventually start to abstract it away
entirely so that the caller doesn't even know what kind of store it
uses.

Note that we only need to adjust a relatively small number of callers,
way less than one might expect. This is because most callers are using
`repo_for_each_pack()`, which handles enumeration of all packfiles that
exist in the repository. So for now, none of these callers need to be
adapted. The remaining callers that iterate through the packfiles
directly and that need adjustment are those that are a bit more tangled
with packfiles. These will be adjusted over time.

Note that this patch only moves the packfile store, and there is still a
bunch of functions that seemingly operate on a packfile store but that
end up iterating over all sources. These will be adjusted in subsequent
commits.

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

1 files changed, 23 insertions, 14 deletions

diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 7849005ccb..b8a7757cfd 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -900,7 +900,7 @@ static void end_packfile(void)
 		idx_name = keep_pack(create_index());
 
 		/* Register the packfile with core git's machinery. */
-		new_p = packfile_store_load_pack(pack_data->repo->objects->packfiles,
+		new_p = packfile_store_load_pack(pack_data->repo->objects->sources->packfiles,
 						 idx_name, 1);
 		if (!new_p)
 			die(_("core Git rejected index %s"), idx_name);
@@ -955,7 +955,7 @@ static int store_object(
 	struct object_id *oidout,
 	uintmax_t mark)
 {
-	struct packfile_store *packs = the_repository->objects->packfiles;
+	struct odb_source *source;
 	void *out, *delta;
 	struct object_entry *e;
 	unsigned char hdr[96];
@@ -979,7 +979,11 @@ static int store_object(
 	if (e->idx.offset) {
 		duplicate_count_by_type[type]++;
 		return 1;
-	} else if (packfile_list_find_oid(packfile_store_get_packs(packs), &oid)) {
+	}
+
+	for (source = the_repository->objects->sources; source; source = source->next) {
+		if (!packfile_list_find_oid(packfile_store_get_packs(source->packfiles), &oid))
+			continue;
 		e->type = type;
 		e->pack_id = MAX_PACK_ID;
 		e->idx.offset = 1; /* just not zero! */
@@ -1096,10 +1100,10 @@ static void truncate_pack(struct hashfile_checkpoint *checkpoint)
 
 static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 {
-	struct packfile_store *packs = the_repository->objects->packfiles;
 	size_t in_sz = 64 * 1024, out_sz = 64 * 1024;
 	unsigned char *in_buf = xmalloc(in_sz);
 	unsigned char *out_buf = xmalloc(out_sz);
+	struct odb_source *source;
 	struct object_entry *e;
 	struct object_id oid;
 	unsigned long hdrlen;
@@ -1179,24 +1183,29 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 	if (e->idx.offset) {
 		duplicate_count_by_type[OBJ_BLOB]++;
 		truncate_pack(&checkpoint);
+		goto out;
+	}
 
-	} else if (packfile_list_find_oid(packfile_store_get_packs(packs), &oid)) {
+	for (source = the_repository->objects->sources; source; source = source->next) {
+		if (!packfile_list_find_oid(packfile_store_get_packs(source->packfiles), &oid))
+			continue;
 		e->type = OBJ_BLOB;
 		e->pack_id = MAX_PACK_ID;
 		e->idx.offset = 1; /* just not zero! */
 		duplicate_count_by_type[OBJ_BLOB]++;
 		truncate_pack(&checkpoint);
-
-	} else {
-		e->depth = 0;
-		e->type = OBJ_BLOB;
-		e->pack_id = pack_id;
-		e->idx.offset = offset;
-		e->idx.crc32 = crc32_end(pack_file);
-		object_count++;
-		object_count_by_type[OBJ_BLOB]++;
+		goto out;
 	}
 
+	e->depth = 0;
+	e->type = OBJ_BLOB;
+	e->pack_id = pack_id;
+	e->idx.offset = offset;
+	e->idx.crc32 = crc32_end(pack_file);
+	object_count++;
+	object_count_by_type[OBJ_BLOB]++;
+
+out:
 	free(in_buf);
 	free(out_buf);
 }