lib/refs: Add methods for setting/listing collection–refs

These are tuples of (collection ID, ref name) which are a globally-unique
form of local ref. They use OstreeCollectionRef as an identifier, and hence
need to be accessed using new API, as the existing API uses string
identifiers and sometimes accepts refspecs. Remote names are not
supported as part an OstreeCollectionRef.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #924
Approved by: cgwalters

src/libostree/ostree-repo-private.h

@@ -48,6 +48,8 @@ G_BEGIN_DECLS
 /* Well-known keys for the additional metadata field in a summary file. */
 #define OSTREE_SUMMARY_LAST_MODIFIED "ostree.summary.last-modified"
 #define OSTREE_SUMMARY_EXPIRES "ostree.summary.expires"
+#define OSTREE_SUMMARY_COLLECTION_ID "ostree.summary.collection-id"
+#define OSTREE_SUMMARY_COLLECTION_MAP "ostree.summary.collection-map"
 
 /* Well-known keys for the additional metadata field in a commit in a ref entry
  * in a summary file. */
@@ -96,7 +98,8 @@ struct OstreeRepo {
   GFile *sysroot_dir;
   char *remotes_config_dir;
 
-  GHashTable *txn_refs;
+  GHashTable *txn_refs;  /* (element-type utf8 utf8) */
+  GHashTable *txn_collection_refs;  /* (element-type OstreeCollectionRef utf8) */
   GMutex txn_stats_lock;
   OstreeRepoTransactionStats txn_stats;
 
@@ -221,7 +224,13 @@ _ostree_repo_update_refs (OstreeRepo        *self,
                           GCancellable      *cancellable,
                           GError           **error);
 
-gboolean      
+gboolean
+_ostree_repo_update_collection_refs (OstreeRepo    *self,
+                                     GHashTable    *refs,
+                                     GCancellable  *cancellable,
+                                     GError       **error);
+
+gboolean
 _ostree_repo_file_replace_contents (OstreeRepo    *self,
                                     int            dfd,
                                     const char    *path,
@@ -230,13 +239,13 @@ _ostree_repo_file_replace_contents (OstreeRepo    *self,
                                     GCancellable  *cancellable,
                                     GError       **error);
 
-gboolean      
-_ostree_repo_write_ref (OstreeRepo    *self,
-                        const char    *remote,
-                        const char    *ref,
-                        const char    *rev,
-                        GCancellable  *cancellable,
-                        GError       **error);
+gboolean
+_ostree_repo_write_ref (OstreeRepo                 *self,
+                        const char                 *remote,
+                        const OstreeCollectionRef  *ref,
+                        const char                 *rev,
+                        GCancellable               *cancellable,
+                        GError                    **error);
 
 OstreeRepoFile *
 _ostree_repo_file_new_for_commit (OstreeRepo  *repo,
@@ -358,6 +367,22 @@ gboolean      ostree_repo_set_collection_id (OstreeRepo   *self,
                                              const gchar  *collection_id,
                                              GError      **error);
 
+gboolean      ostree_repo_list_collection_refs (OstreeRepo    *self,
+                                                const char    *match_collection_id,
+                                                GHashTable   **out_all_refs,
+                                                GCancellable  *cancellable,
+                                                GError       **error);
+
+void          ostree_repo_transaction_set_collection_ref (OstreeRepo                *self,
+                                                          const OstreeCollectionRef *ref,
+                                                          const char                *checksum);
+
+gboolean      ostree_repo_set_collection_ref_immediate (OstreeRepo                 *self,
+                                                        const OstreeCollectionRef  *ref,
+                                                        const char                 *checksum,
+                                                        GCancellable               *cancellable,
+                                                        GError                    **error);
+
 #endif  /* !OSTREE_ENABLE_EXPERIMENTAL_API */
 
 G_END_DECLS