LightDirectory: new struct replacing Directory in the DB API

Makefile.am

@@ -197,6 +197,7 @@ src_mpd_SOURCES = \
 	src/SignalHandlers.cxx src/SignalHandlers.hxx \
 	src/DetachedSong.cxx src/DetachedSong.hxx \
 	src/LightSong.cxx src/LightSong.hxx \
+	src/LightDirectory.hxx \
 	src/Song.cxx src/Song.hxx \
 	src/SongUpdate.cxx \
 	src/SongPrint.cxx src/SongPrint.hxx \

src/DatabasePrint.cxx

@@ -23,17 +23,18 @@
 #include "SongFilter.hxx"
 #include "SongPrint.hxx"
 #include "TimePrint.hxx"
-#include "Directory.hxx"
 #include "Client.hxx"
 #include "tag/Tag.hxx"
 #include "LightSong.hxx"
+#include "LightDirectory.hxx"
+#include "PlaylistInfo.hxx"
 #include "DatabaseGlue.hxx"
 #include "DatabasePlugin.hxx"
 
 #include <functional>
 
 static bool
-PrintDirectoryBrief(Client &client, const Directory &directory)
+PrintDirectoryBrief(Client &client, const LightDirectory &directory)
 {
 	if (!directory.IsRoot())
 		client_printf(client, "directory: %s\n", directory.GetPath());
@@ -42,7 +43,7 @@ PrintDirectoryBrief(Client &client, const Directory &directory)
 }
 
 static bool
-PrintDirectoryFull(Client &client, const Directory &directory)
+PrintDirectoryFull(Client &client, const LightDirectory &directory)
 {
 	if (!directory.IsRoot()) {
 		client_printf(client, "directory: %s\n", directory.GetPath());
@@ -68,7 +69,7 @@ print_playlist_in_directory(Client &client,
 
 static void
 print_playlist_in_directory(Client &client,
-			    const Directory *directory,
+			    const LightDirectory *directory,
 			    const char *name_utf8)
 {
 	if (directory == nullptr || directory->IsRoot())
@@ -105,7 +106,7 @@ PrintSongFull(Client &client, const LightSong &song)
 static bool
 PrintPlaylistBrief(Client &client,
 		   const PlaylistInfo &playlist,
-		   const Directory &directory)
+		   const LightDirectory &directory)
 {
 	print_playlist_in_directory(client, &directory, playlist.name.c_str());
 	return true;
@@ -114,7 +115,7 @@ PrintPlaylistBrief(Client &client,
 static bool
 PrintPlaylistFull(Client &client,
 		  const PlaylistInfo &playlist,
-		  const Directory &directory)
+		  const LightDirectory &directory)
 {
 	print_playlist_in_directory(client, &directory, playlist.name.c_str());
 

src/DatabaseVisitor.hxx

@@ -22,14 +22,14 @@
 
 #include <functional>
 
-struct Directory;
+struct LightDirectory;
 struct LightSong;
 struct PlaylistInfo;
 class Error;
 
-typedef std::function<bool(const Directory &, Error &)> VisitDirectory;
+typedef std::function<bool(const LightDirectory &, Error &)> VisitDirectory;
 typedef std::function<bool(const LightSong &, Error &)> VisitSong;
-typedef std::function<bool(const PlaylistInfo &, const Directory &,
+typedef std::function<bool(const PlaylistInfo &, const LightDirectory &,
 			   Error &)> VisitPlaylist;
 
 typedef std::function<bool(const char *, Error &)> VisitString;

src/Directory.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "Directory.hxx"
+#include "LightDirectory.hxx"
 #include "SongFilter.hxx"
 #include "PlaylistVector.hxx"
 #include "DatabaseLock.hxx"
@@ -272,14 +273,14 @@ Directory::Walk(bool recursive, const SongFilter *filter,
 
 	if (visit_playlist) {
 		for (const PlaylistInfo &p : playlists)
-			if (!visit_playlist(p, *this, error))
+			if (!visit_playlist(p, Export(), error))
 				return false;
 	}
 
 	Directory *child;
 	directory_for_each_child(child, *this) {
 		if (visit_directory &&
-		    !visit_directory(*child, error))
+		    !visit_directory(child->Export(), error))
 			return false;
 
 		if (recursive &&
@@ -291,3 +292,9 @@ Directory::Walk(bool recursive, const SongFilter *filter,
 
 	return true;
 }
+
+LightDirectory
+Directory::Export() const
+{
+	return LightDirectory(GetPath(), mtime);
+}

src/Directory.hxx

@@ -234,6 +234,9 @@ public:
 		  VisitDirectory visit_directory, VisitSong visit_song,
 		  VisitPlaylist visit_playlist,
 		  Error &error) const;
+
+	gcc_pure
+	LightDirectory Export() const;
 };
 
 static inline bool

src/LightDirectory.hxx

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_LIGHT_DIRECTORY_HXX
+#define MPD_LIGHT_DIRECTORY_HXX
+
+#include "Compiler.h"
+
+#include <string>
+
+#include <time.h>
+
+struct Tag;
+
+/**
+ * A reference to a directory.  Unlike the #Directory class, this one
+ * consists only of pointers.  It is supposed to be as light as
+ * possible while still providing all the information MPD has about a
+ * directory.  This class does not manage any memory, and the pointers
+ * become invalid quickly.  Only to be used to pass around during
+ * well-defined situations.
+ */
+struct LightDirectory {
+	const char *uri;
+
+	time_t mtime;
+
+	constexpr LightDirectory(const char *_uri, time_t _mtime)
+		:uri(_uri), mtime(_mtime) {}
+
+	static constexpr LightDirectory Root() {
+		return LightDirectory("", 0);
+	}
+
+	bool IsRoot() const {
+		return *uri == 0;
+	}
+
+	gcc_pure
+	const char *GetPath() const {
+		return uri;
+	}
+};
+
+#endif

src/SongPrint.cxx

@@ -21,7 +21,6 @@
 #include "SongPrint.hxx"
 #include "LightSong.hxx"
 #include "DetachedSong.hxx"
-#include "Directory.hxx"
 #include "TimePrint.hxx"
 #include "TagPrint.hxx"
 #include "Mapper.hxx"

src/command/OtherCommands.cxx

@@ -42,6 +42,7 @@
 #include "Stats.hxx"
 #include "Permission.hxx"
 #include "PlaylistFile.hxx"
+#include "PlaylistVector.hxx"
 #include "ClientFile.hxx"
 #include "Client.hxx"
 #include "Idle.hxx"

src/db/ProxyDatabasePlugin.cxx

@@ -23,7 +23,8 @@
 #include "DatabaseListener.hxx"
 #include "DatabaseSelection.hxx"
 #include "DatabaseError.hxx"
-#include "Directory.hxx"
+#include "PlaylistInfo.hxx"
+#include "LightDirectory.hxx"
 #include "LightSong.hxx"
 #include "SongFilter.hxx"
 #include "Compiler.h"
@@ -71,7 +72,6 @@ class ProxyDatabase final : public Database, SocketMonitor, IdleMonitor {
 	unsigned port;
 
 	struct mpd_connection *connection;
-	Directory *root;
 
 	/* this is mutable because GetStats() must be "const" */
 	mutable time_t update_stamp;
@@ -328,7 +328,6 @@ ProxyDatabase::Open(Error &error)
 	if (!Connect(error))
 		return false;
 
-	root = Directory::NewRoot();
 	update_stamp = 0;
 
 	return true;
@@ -337,8 +336,6 @@ ProxyDatabase::Open(Error &error)
 void
 ProxyDatabase::Close()
 {
-	delete root;
-
 	if (connection != nullptr)
 		Disconnect();
 }
@@ -515,13 +512,13 @@ ProxyDatabase::ReturnSong(const LightSong *_song) const
 }
 
 static bool
-Visit(struct mpd_connection *connection, Directory &root, const char *uri,
+Visit(struct mpd_connection *connection, const char *uri,
       bool recursive, const SongFilter *filter,
       VisitDirectory visit_directory, VisitSong visit_song,
       VisitPlaylist visit_playlist, Error &error);
 
 static bool
-Visit(struct mpd_connection *connection, Directory &root,
+Visit(struct mpd_connection *connection,
       bool recursive, const SongFilter *filter,
       const struct mpd_directory *directory,
       VisitDirectory visit_directory, VisitSong visit_song,
@@ -530,11 +527,11 @@ Visit(struct mpd_connection *connection, Directory &root,
 	const char *path = mpd_directory_get_path(directory);
 
 	if (visit_directory &&
-	    !visit_directory(Directory(path, &root), error))
+	    !visit_directory(LightDirectory(path, 0), error))
 		return false;
 
 	if (recursive &&
-	    !Visit(connection, root, path, recursive, filter,
+	    !Visit(connection, path, recursive, filter,
 		   visit_directory, visit_song, visit_playlist, error))
 		return false;
 
@@ -561,7 +558,7 @@ Visit(const SongFilter *filter,
 }
 
 static bool
-Visit(const struct mpd_playlist *playlist, Directory &root,
+Visit(const struct mpd_playlist *playlist,
       VisitPlaylist visit_playlist, Error &error)
 {
 	if (!visit_playlist)
@@ -570,7 +567,7 @@ Visit(const struct mpd_playlist *playlist, Directory &root,
 	PlaylistInfo p(mpd_playlist_get_path(playlist),
 		       mpd_playlist_get_last_modified(playlist));
 
-	return visit_playlist(p, root, error);
+	return visit_playlist(p, LightDirectory::Root(), error);
 }
 
 class ProxyEntity {
@@ -612,7 +609,7 @@ ReceiveEntities(struct mpd_connection *connection)
 }
 
 static bool
-Visit(struct mpd_connection *connection, Directory &root, const char *uri,
+Visit(struct mpd_connection *connection, const char *uri,
       bool recursive, const SongFilter *filter,
       VisitDirectory visit_directory, VisitSong visit_song,
       VisitPlaylist visit_playlist, Error &error)
@@ -630,7 +627,7 @@ Visit(struct mpd_connection *connection, Directory &root, const char *uri,
 			break;
 
 		case MPD_ENTITY_TYPE_DIRECTORY:
-			if (!Visit(connection, root, recursive, filter,
+			if (!Visit(connection, recursive, filter,
 				   mpd_entity_get_directory(entity),
 				   visit_directory, visit_song, visit_playlist,
 				   error))
@@ -645,7 +642,7 @@ Visit(struct mpd_connection *connection, Directory &root, const char *uri,
 			break;
 
 		case MPD_ENTITY_TYPE_PLAYLIST:
-			if (!Visit(mpd_entity_get_playlist(entity), root,
+			if (!Visit(mpd_entity_get_playlist(entity),
 				   visit_playlist, error))
 				return false;
 			break;
@@ -702,7 +699,7 @@ ProxyDatabase::Visit(const DatabaseSelection &selection,
 		return ::SearchSongs(connection, selection, visit_song, error);
 
 	/* fall back to recursive walk (slow!) */
-	return ::Visit(connection, *root, selection.uri.c_str(),
+	return ::Visit(connection, selection.uri.c_str(),
 		       selection.recursive, selection.filter,
 		       visit_directory, visit_song, visit_playlist,
 		       error);

src/db/SimpleDatabasePlugin.cxx

@@ -21,6 +21,7 @@
 #include "SimpleDatabasePlugin.hxx"
 #include "DatabaseSelection.hxx"
 #include "DatabaseHelpers.hxx"
+#include "LightDirectory.hxx"
 #include "Directory.hxx"
 #include "Song.hxx"
 #include "SongFilter.hxx"
@@ -265,7 +266,7 @@ SimpleDatabase::Visit(const DatabaseSelection &selection,
 	}
 
 	if (selection.recursive && visit_directory &&
-	    !visit_directory(*directory, error))
+	    !visit_directory(directory->Export(), error))
 		return false;
 
 	return directory->Walk(selection.recursive, selection.filter,

src/db/UpnpDatabasePlugin.cxx

@@ -29,8 +29,7 @@
 #include "DatabasePlugin.hxx"
 #include "DatabaseSelection.hxx"
 #include "DatabaseError.hxx"
-#include "PlaylistVector.hxx"
+#include "LightDirectory.hxx"
-#include "Directory.hxx"
 #include "LightSong.hxx"
 #include "ConfigData.hxx"
 #include "tag/TagBuilder.hxx"
@@ -71,7 +70,6 @@ public:
 class UpnpDatabase : public Database {
 	LibUPnP *m_lib;
 	UPnPDeviceDirectory *m_superdir;
-	Directory *m_root;
 
 public:
 	static Database *Create(EventLoop &loop, DatabaseListener &listener,
@@ -190,7 +188,6 @@ UpnpDatabase::Open(Error &error)
 		return false;
 	}
 
-	m_root = Directory::NewRoot();
 	// Wait for device answers. This should be consistent with the value set
 	// in the lib (currently 2)
 	sleep(2);
@@ -200,7 +197,6 @@ UpnpDatabase::Open(Error &error)
 void
 UpnpDatabase::Close()
 {
-	delete m_root;
 	delete m_superdir;
 	delete m_lib;
 }
@@ -602,9 +598,8 @@ UpnpDatabase::VisitServer(ContentDirectoryService &server,
 
 		case UPnPDirObject::Type::CONTAINER:
 			if (visit_directory) {
-				Directory d((selection.uri + "/" +
+				const std::string uri = selection.uri + "/" + dirent.name;
-					     dirent.name).c_str(),
+				const LightDirectory d(uri.c_str(), 0);
-					    m_root);
 				if (!visit_directory(d, error))
 					return false;
 			}
@@ -673,7 +668,7 @@ UpnpDatabase::Visit(const DatabaseSelection &selection,
 			// pseudo-directory from the list of servers.
 			if (visit_directory) {
 				for (auto& server : servers) {
-					Directory d(server.getFriendlyName(), m_root);
+					const LightDirectory d(server.getFriendlyName(), 0);
 					if (!visit_directory(d, error))
 						return false;
 				}

test/DumpDatabase.cxx

@@ -22,7 +22,7 @@
 #include "DatabasePlugin.hxx"
 #include "DatabaseSelection.hxx"
 #include "DatabaseListener.hxx"
-#include "Directory.hxx"
+#include "LightDirectory.hxx"
 #include "LightSong.hxx"
 #include "PlaylistVector.hxx"
 #include "ConfigGlobal.hxx"
@@ -58,9 +58,9 @@ public:
 };
 
 static bool
-DumpDirectory(const Directory &directory, Error &)
+DumpDirectory(const LightDirectory &directory, Error &)
 {
-	cout << "D " << directory.path << endl;
+	cout << "D " << directory.GetPath() << endl;
 	return true;
 }
 
@@ -76,9 +76,10 @@ DumpSong(const LightSong &song, Error &)
 
 static bool
 DumpPlaylist(const PlaylistInfo &playlist,
-	     const Directory &directory, Error &)
+	     const LightDirectory &directory, Error &)
 {
-	cout << "P " << directory.path << "/" << playlist.name.c_str() << endl;
+	cout << "P " << directory.GetPath()
+	     << "/" << playlist.name.c_str() << endl;
 	return true;
 }