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 <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

loose.c

@@ -1,6 +1,7 @@
 #include"git-compat-util.h"
 #include"hash.h"
 #include"path.h"
+#include"object-file.h"
 #include"odb.h"
 #include"hex.h"
 #include"repository.h"
@@ -54,7 +55,7 @@ static int insert_loose_map(struct odb_source *source,
 inserted |= insert_oid_pair(map->to_compat, oid, compat_oid);
 inserted |= insert_oid_pair(map->to_storage, compat_oid, oid);
 if (inserted)
-oidtree_insert(source->loose_objects_cache, compat_oid);
+oidtree_insert(source->loose->cache, compat_oid);
 
 returninserted;
 }
@@ -66,9 +67,9 @@ static int load_one_loose_object_map(struct repository *repo, struct odb_source
 
 if (!source->loose_map)
 loose_object_map_init(&source->loose_map);
-if (!source->loose_objects_cache){
-ALLOC_ARRAY(source->loose_objects_cache, 1);
-oidtree_init(source->loose_objects_cache);
+if (!source->loose->cache){
+ALLOC_ARRAY(source->loose->cache, 1);
+oidtree_init(source->loose->cache);
  }
 
 insert_loose_map(source, repo->hash_algo->empty_tree, repo->compat_hash_algo->empty_tree);

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))
 return1;
  }
 return0;
@@ -1802,44 +1802,44 @@ static int append_loose_object(const struct object_id *oid,
 return0;
 }
 
-structoidtree*odb_loose_cache(structodb_source*source,
-conststructobject_id*oid)
+structoidtree*odb_source_loose_cache(structodb_source*source,
+conststructobject_id*oid)
 {
 intsubdir_nr=oid->hash[0];
 structstrbufbuf=STRBUF_INIT;
-size_tword_bits=bitsizeof(source->loose_objects_subdir_seen[0]);
+size_tword_bits=bitsizeof(source->loose->subdir_seen[0]);
 size_tword_index=subdir_nr / word_bits;
 size_tmask= (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)
-returnsource->loose_objects_cache;
-if (!source->loose_objects_cache){
-ALLOC_ARRAY(source->loose_objects_cache, 1);
-oidtree_init(source->loose_objects_cache);
+returnsource->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);
-returnsource->loose_objects_cache;
+returnsource->loose->cache;
 }
 
 voidodb_clear_loose_cache(structodb_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));
 }
 
 staticintcheck_stream_oid(git_zstream*stream,
@@ -2006,5 +2006,8 @@ struct odb_source_loose *odb_source_loose_new(struct odb_source *source)
 
 voidodb_source_loose_free(structodb_source_loose*loose)
 {
+if (!loose)
+return;
+odb_clear_loose_cache(loose->source);
 free(loose);
 }

object-file.h

@@ -20,6 +20,18 @@ struct odb_source;
 
 structodb_source_loose{
 structodb_source*source;
+
+/*
+ * Used to store the results of readdir(3) calls when we are OK
+ * sacrificing accuracy due to races for speed. That includes
+ * object existence with OBJECT_INFO_QUICK, as well as
+ * our search for unique abbreviated hashes. Don't use it for tasks
+ * requiring greater accuracy!
+ *
+ * Be sure to call odb_load_loose_cache() before using.
+ */
+uint32_tsubdir_seen[8]; /* 256 bits */
+structoidtree*cache;
 };
 
 structodb_source_loose*odb_source_loose_new(structodb_source*source);
@@ -29,8 +41,8 @@ void odb_source_loose_free(struct odb_source_loose *loose);
  * Populate and return the loose object cache array corresponding to the
  * given object ID.
  */
-structoidtree*odb_loose_cache(structodb_source*source,
-conststructobject_id*oid);
+structoidtree*odb_source_loose_cache(structodb_source*source,
+conststructobject_id*oid);
 
 /* Empty the loose object cache for the specified object directory. */
 voidodb_clear_loose_cache(structodb_source*source);

object-name.c

@@ -116,7 +116,7 @@ static void find_short_object_filename(struct disambiguate_state *ds)
 structodb_source*source;
 
 for (source=ds->repo->objects->sources; source&& !ds->ambiguous; source=source->next)
-oidtree_each(odb_loose_cache(source, &ds->bin_pfx),
+oidtree_each(odb_source_loose_cache(source, &ds->bin_pfx),
 &ds->bin_pfx, ds->len, match_prefix, ds);
 }
 

odb.c

@@ -370,7 +370,6 @@ static void odb_source_free(struct odb_source *source)
 {
 free(source->path);
 odb_source_loose_free(source->loose);
-odb_clear_loose_cache(source);
 loose_object_map_clear(&source->loose_map);
 free(source);
 }

odb.h

@@ -51,18 +51,6 @@ struct odb_source{
 /* Private state for loose objects. */
 structodb_source_loose*loose;
 
-/*
- * Used to store the results of readdir(3) calls when we are OK
- * sacrificing accuracy due to races for speed. That includes
- * object existence with OBJECT_INFO_QUICK, as well as
- * our search for unique abbreviated hashes. Don't use it for tasks
- * requiring greater accuracy!
- *
- * Be sure to call odb_load_loose_cache() before using.
- */
-uint32_tloose_objects_subdir_seen[8]; /* 256 bits */
-structoidtree*loose_objects_cache;
-
 /* Map between object IDs for loose objects. */
 structloose_object_map*loose_map;