db/Interface: add attribute "plugin"

The new method IsPlugin() replaces the "is_simple" flag.

src/Main.cxx

@@ -166,11 +166,10 @@ InitStorage(Error &error)
 static bool
 glue_db_init_and_load(void)
 {
-	bool is_simple;
 	Error error;
 	instance->database =
 		CreateConfiguredDatabase(*instance->event_loop, *instance,
-					 is_simple, error);
+					 error);
 	if (instance->database == nullptr) {
 		if (error.IsDefined())
 			FatalError(error);
@@ -193,7 +192,7 @@ glue_db_init_and_load(void)
 	if (!instance->database->Open(error))
 		FatalError(error);
 
-	if (!is_simple)
+	if (!instance->database->IsPlugin(simple_db_plugin))
 		return true;
 
 	SimpleDatabase &db = *(SimpleDatabase *)instance->database;

src/db/Configured.cxx

@@ -28,7 +28,7 @@
 
 Database *
 CreateConfiguredDatabase(EventLoop &loop, DatabaseListener &listener,
-			 bool &is_simple_r, Error &error)
+			 Error &error)
 {
 	const struct config_param *param = config_get_param(CONF_DATABASE);
 	const struct config_param *path = config_get_param(CONF_DB_FILE);
@@ -53,7 +53,7 @@ CreateConfiguredDatabase(EventLoop &loop, DatabaseListener &listener,
 		return nullptr;
 
 	Database *db = DatabaseGlobalInit(loop, listener, *param,
-					  is_simple_r, error);
+					  error);
 	delete allocated;
 	return db;
 }

src/db/Configured.hxx

@@ -34,6 +34,6 @@ class Error;
  */
 Database *
 CreateConfiguredDatabase(EventLoop &loop, DatabaseListener &listener,
-			 bool &is_simple_r, Error &error);
+			 Error &error);
 
 #endif

src/db/DatabaseGlue.cxx

@@ -29,11 +29,10 @@
 
 Database *
 DatabaseGlobalInit(EventLoop &loop, DatabaseListener &listener,
-		   const config_param &param, bool &is_simple, Error &error)
+		   const config_param &param, Error &error)
 {
 	const char *plugin_name =
 		param.GetBlockValue("plugin", "simple");
-	is_simple = strcmp(plugin_name, "simple") == 0;
 
 	const DatabasePlugin *plugin = GetDatabasePluginByName(plugin_name);
 	if (plugin == nullptr) {

src/db/DatabaseGlue.hxx

@@ -32,11 +32,9 @@ class Error;
  * Initialize the database library.
  *
  * @param param the database configuration block
- * @param is_simple returns whether this is the "simple" database
- * plugin
  */
 Database *
 DatabaseGlobalInit(EventLoop &loop, DatabaseListener &listener,
-		   const config_param &param, bool &is_simple, Error &error);
+		   const config_param &param, Error &error);
 
 #endif

src/db/Interface.hxx

@@ -26,18 +26,32 @@
 
 #include <time.h>
 
+struct DatabasePlugin;
 struct DatabaseStats;
 struct DatabaseSelection;
 struct LightSong;
 class Error;
 
 class Database {
+	const DatabasePlugin &plugin;
+
 public:
+	Database(const DatabasePlugin &_plugin)
+		:plugin(_plugin) {}
+
 	/**
 	 * Free instance data.
          */
 	virtual ~Database() {}
 
+	const DatabasePlugin &GetPlugin() const {
+		return plugin;
+	}
+
+	bool IsPlugin(const DatabasePlugin &other) const {
+		return &plugin == &other;
+	}
+
 	/**
          * Open the database.  Read it into memory if applicable.
 	 */

src/db/plugins/LazyDatabase.cxx

@@ -23,6 +23,9 @@
 
 #include <assert.h>
 
+LazyDatabase::LazyDatabase(Database *_db)
+	:Database(_db->GetPlugin()), db(_db), open(false) {}
+
 LazyDatabase::~LazyDatabase()
 {
 	assert(!open);

src/db/plugins/LazyDatabase.hxx

@@ -35,8 +35,7 @@ class LazyDatabase final : public Database {
 
 public:
 	gcc_nonnull_all
-	LazyDatabase(Database *_db)
-		:db(_db), open(false) {}
+	LazyDatabase(Database *_db);
 
 	virtual ~LazyDatabase();
 

src/db/plugins/ProxyDatabasePlugin.cxx

@@ -91,7 +91,8 @@ class ProxyDatabase final : public Database, SocketMonitor, IdleMonitor {
 
 public:
 	ProxyDatabase(EventLoop &_loop, DatabaseListener &_listener)
-		:SocketMonitor(_loop), IdleMonitor(_loop),
+		:Database(proxy_db_plugin),
+		 SocketMonitor(_loop), IdleMonitor(_loop),
 		 listener(_listener) {}
 
 	static Database *Create(EventLoop &loop, DatabaseListener &listener,

src/db/plugins/SimpleDatabasePlugin.cxx

@@ -40,6 +40,10 @@
 
 static constexpr Domain simple_db_domain("simple_db");
 
+inline SimpleDatabase::SimpleDatabase()
+	:Database(simple_db_plugin),
+	 path(AllocatedPath::Null()) {}
+
 Database *
 SimpleDatabase::Create(gcc_unused EventLoop &loop,
 		       gcc_unused DatabaseListener &listener,

src/db/plugins/SimpleDatabasePlugin.hxx

@@ -50,8 +50,7 @@ class SimpleDatabase : public Database {
 	mutable unsigned borrowed_song_count;
 #endif
 
-	SimpleDatabase()
-		:path(AllocatedPath::Null()) {}
+	SimpleDatabase();
 
 public:
 	gcc_pure

src/db/plugins/UpnpDatabasePlugin.cxx

@@ -75,6 +75,8 @@ class UpnpDatabase : public Database {
 	UPnPDeviceDirectory *discovery;
 
 public:
+	UpnpDatabase():Database(upnp_db_plugin) {}
+
 	static Database *Create(EventLoop &loop, DatabaseListener &listener,
 				const config_param &param,
 				Error &error);