Submodule status improvements

This fixes the way that submodule status is checked to bypass just
about all of the caching in the submodule object.  Based on the
ignore value, it will try to do the minimum work necessary to find
the current status of the submodule - but it will actually go to
disk to get all of the current values.

This also removes the custom refcounting stuff in favor of the
common git_refcount style.  Right now, it is still for internal
purposes only, but it should make it easier to add true submodule
refcounting in the future with a public git_submodule_free call
that will allow bindings not to worry about the submodule object
getting freed from underneath them.

include/git2/submodule.h

@@ -119,19 +119,9 @@ typedef enum {
 	GIT_SUBMODULE_STATUS_WD_UNTRACKED      = (1u << 13),
 } git_submodule_status_t;
 
-#define GIT_SUBMODULE_STATUS__IN_FLAGS \
-	(GIT_SUBMODULE_STATUS_IN_HEAD | \
-	GIT_SUBMODULE_STATUS_IN_INDEX | \
-	GIT_SUBMODULE_STATUS_IN_CONFIG | \
-	GIT_SUBMODULE_STATUS_IN_WD)
-
-#define GIT_SUBMODULE_STATUS__INDEX_FLAGS \
-	(GIT_SUBMODULE_STATUS_INDEX_ADDED | \
-	GIT_SUBMODULE_STATUS_INDEX_DELETED | \
-	GIT_SUBMODULE_STATUS_INDEX_MODIFIED)
-
-#define GIT_SUBMODULE_STATUS__WD_FLAGS \
-	~(GIT_SUBMODULE_STATUS__IN_FLAGS | GIT_SUBMODULE_STATUS__INDEX_FLAGS)
+#define GIT_SUBMODULE_STATUS__IN_FLAGS		0x000Fu
+#define GIT_SUBMODULE_STATUS__INDEX_FLAGS	0x0070u
+#define GIT_SUBMODULE_STATUS__WD_FLAGS		0x3F80u
 
 #define GIT_SUBMODULE_STATUS_IS_UNMODIFIED(S) \
 	(((S) & ~GIT_SUBMODULE_STATUS__IN_FLAGS) == 0)

src/submodule.h

@@ -48,6 +48,10 @@
  * an entry for every submodule found in the HEAD and index, and for every
  * submodule described in .gitmodules.  The fields are as follows:
  *
+ * - `rc` tracks the refcount of how many hash table entries in the
+ *   git_submodule_cache there are for this submodule.  It only comes into
+ *   play if the name and path of the submodule differ.
+ *
  * - `name` is the name of the submodule from .gitmodules.
  * - `path` is the path to the submodule from the repo root.  It is almost
  *    always the same as `name`.
@@ -58,18 +62,12 @@
  * - `ignore_default` is the ignore value from the config
  * - `fetch_recurse` is 0 or 1 - see gitmodules(5) fetchRecurseSubmodules.
  *
- * - `owner` is the git_repository containing this submodule
+ * - `repo` is the parent repository that contains this submodule.
  * - `flags` after for internal use, tracking where this submodule has been
  *   found (head, index, config, workdir) and known status info, etc.
  * - `head_oid` is the SHA1 for the submodule path in the repo HEAD.
  * - `index_oid` is the SHA1 for the submodule recorded in the index.
  * - `wd_oid` is the SHA1 for the HEAD of the checked out submodule.
- * - `wd_index_path` is the path to the index of the checked out submodule
- * - `wd_last_index` is a timestamp of that submodule index so we can
- *   quickly check if the `wd_oid` should be rechecked
- * - `refcount` tracks how many hash table entries in the
- *   git_submodule_cache there are for this submodule.  It only comes into
- *   play if the name and path of the submodule differ.
  *
  * If the submodule has been added to .gitmodules but not yet git added,
  * then the `index_oid` will be zero but still marked valid.  If the
@@ -77,9 +75,11 @@
  * then the `index_oid` will be set, but the `url` will be NULL.
  */
 struct git_submodule {
+	git_refcount rc;
+
 	/* information from config */
 	char *name;
-	char *path; /* important: may point to same string data as "name" */
+	char *path; /* important: may just point to "name" string */
 	char *url;
 	git_submodule_update_t update;
 	git_submodule_update_t update_default;
@@ -88,14 +88,11 @@ struct git_submodule {
 	int fetch_recurse;
 
 	/* internal information */
-	git_repository *owner;
+	git_repository *repo;
 	uint32_t flags;
 	git_oid head_oid;
 	git_oid index_oid;
 	git_oid wd_oid;
-	char *wd_head_path;
-	git_futils_filestamp wd_stamp;
-	int refcount;
 };
 
 /* Additional flags on top of public GIT_SUBMODULE_STATUS values */
@@ -113,4 +110,21 @@ enum {
 #define GIT_SUBMODULE_STATUS__CLEAR_INTERNAL(S) \
 	((S) & ~(0xFFFFFFFFu << 20))
 
+/* Internal status fn returns status and optionally the various OIDs */
+extern int git_submodule__status(
+	unsigned int *out_status,
+	git_oid *out_head_id,
+	git_oid *out_index_id,
+	git_oid *out_wd_id,
+	git_submodule *sm,
+	git_submodule_ignore_t ign);
+
+/* Open submodule repository as bare repo for quick HEAD check, etc. */
+extern int git_submodule_open_bare(
+	git_repository **repo,
+	git_submodule *submodule);
+
+/* Release reference to submodule object - not currently for external use */
+extern void git_submodule_free(git_submodule *sm);
+
 #endif