Add an alpm_db_get_valid() public function

This allows one to check if a database is valid or invalid.

Signed-off-by: Dan McGee <dan@archlinux.org>

lib/libalpm/alpm.h

@@ -382,6 +382,14 @@ int alpm_db_unregister_all(alpm_handle_t *handle);
  */
 const char *alpm_db_get_name(const alpm_db_t *db);
 
+/** Check the validity of a database.
+ * This is most useful for sync databases and verifying signature status.
+ * If invalid, the handle error code will be set accordingly.
+ * @param db pointer to the package database
+ * @return 0 if valid, -1 if invalid (pm_errno is set accordingly)
+ */
+int alpm_db_get_valid(alpm_db_t *db);
+
 /** @name Accessors to the list of servers for a database.
  * @{
  */

lib/libalpm/be_local.c

@@ -915,6 +915,7 @@ int _alpm_local_db_remove(alpm_db_t *db, alpm_pkg_t *info)
 }
 
 struct db_operations local_db_ops = {
+	.validate         = local_db_validate,
 	.populate         = local_db_populate,
 	.unregister       = _alpm_db_unregister,
 };

lib/libalpm/be_sync.c

@@ -580,6 +580,7 @@ error:
 }
 
 struct db_operations sync_db_ops = {
+	.validate         = sync_db_validate,
 	.populate         = sync_db_populate,
 	.unregister       = _alpm_db_unregister,
 };

lib/libalpm/db.c

@@ -219,6 +219,14 @@ const char SYMEXPORT *alpm_db_get_name(const alpm_db_t *db)
 	return db->treename;
 }
 
+/** Check the validity of a database. */
+int SYMEXPORT alpm_db_get_valid(alpm_db_t *db)
+{
+	ASSERT(db != NULL, return -1);
+	db->handle->pm_errno = 0;
+	return db->ops->validate(db);
+}
+
 /** Get a package entry from a package database. */
 alpm_pkg_t SYMEXPORT *alpm_db_get_pkg(alpm_db_t *db, const char *name)
 {

lib/libalpm/db.h

@@ -51,6 +51,7 @@ enum _alpm_dbstatus_t {
 };
 
 struct db_operations {
+	int (*validate) (alpm_db_t *);
 	int (*populate) (alpm_db_t *);
 	void (*unregister) (alpm_db_t *);
 };