db/proxy: implement Update()

NEWS

@@ -9,6 +9,7 @@ ver 0.19 (not yet released)
   - "list" and "count" allow grouping
 * database
   - proxy: forward "idle" events
+  - proxy: forward the "update" command
   - proxy: copy "Last-Modified" from remote directories
   - upnp: new plugin
   - cancel the update on shutdown

src/db/plugins/ProxyDatabasePlugin.cxx

@@ -120,6 +120,9 @@ public:
 			      DatabaseStats &stats,
 			      Error &error) const override;
 
+	virtual unsigned Update(const char *uri_utf8, bool discard,
+				Error &error) override;
+
 	virtual time_t GetUpdateStamp() const override {
 		return update_stamp;
 	}
@@ -809,6 +812,22 @@ ProxyDatabase::GetStats(const DatabaseSelection &selection,
 	return true;
 }
 
+unsigned
+ProxyDatabase::Update(const char *uri_utf8, bool discard,
+		      Error &error)
+{
+	if (!EnsureConnected(error))
+		return 0;
+
+	unsigned id = discard
+		? mpd_run_rescan(connection, uri_utf8)
+		: mpd_run_update(connection, uri_utf8);
+	if (id == 0)
+		CheckError(connection, error);
+
+	return id;
+}
+
 const DatabasePlugin proxy_db_plugin = {
 	"proxy",
 	DatabasePlugin::FLAG_REQUIRE_STORAGE,