mpd: make functions take item consumer instead of returning vector of items

14 files changed, 206 insertions, 209 deletions

diff --git a/src/actions.cpp b/src/actions.cpp
index c181a5c6..b23d2b19 100644
--- a/src/actions.cpp
+++ b/src/actions.cpp
@@ -1407,24 +1407,28 @@ void EditLibraryTag::Run()
 		MPD::MutableSong::SetFunction set = tagTypeToSetFunction(Config.media_lib_primary_tag);
 		assert(set);
 		bool success = true;
-		MPD::SongList songs = Mpd.CommitSearchSongs();
-		for (auto s = songs.begin(); s != songs.end(); ++s)
-		{
-			MPD::MutableSong es = *s;
-			es.setTags(set, new_tag, Config.tags_separator);
-			Statusbar::msg("Updating tags in \"%s\"...", es.getName().c_str());
-			std::string path = Config.mpd_music_dir + es.getURI();
-			if (!Tags::write(es))
+		std::string dir_to_update;
+		Mpd.CommitSearchSongs([set, &dir_to_update, &new_tag, &success](MPD::Song &&s) {
+			if (!success)
+				return;
+			MPD::MutableSong ms = s;
+			ms.setTags(set, new_tag, Config.tags_separator);
+			Statusbar::msg("Updating tags in \"%s\"...", ms.getName().c_str());
+			std::string path = Config.mpd_music_dir + ms.getURI();
+			if (!Tags::write(ms))
 			{
 				const char msg[] = "Error while updating tags in \"%ls\"";
-				Statusbar::msg(msg, wideShorten(ToWString(es.getURI()), COLS-const_strlen(msg)).c_str());
+				Statusbar::msg(msg, wideShorten(ToWString(ms.getURI()), COLS-const_strlen(msg)).c_str());
 				success = false;
-				break;
 			}
-		}
+			if (dir_to_update.empty())
+				dir_to_update = s.getURI();
+			else
+				dir_to_update = getSharedDirectory(dir_to_update, s.getURI());
+		});
 		if (success)
 		{
-			Mpd.UpdateDirectory(getSharedDirectory(songs.begin(), songs.end()));
+			Mpd.UpdateDirectory(dir_to_update);
 			Statusbar::msg("Tags updated successfully");
 		}
 	}
diff --git a/src/browser.cpp b/src/browser.cpp
index 015372e5..6cc17881 100644
--- a/src/browser.cpp
+++ b/src/browser.cpp
@@ -325,16 +325,18 @@ MPD::SongList Browser::getSelectedSongs()
 			else
 #			endif // !WIN32
 			{
-				auto list = Mpd.GetDirectoryRecursive(item.name);
-				result.insert(result.end(), list.begin(), list.end());
+				Mpd.GetDirectoryRecursive(item.name, [&result](MPD::Song &&s) {
+					result.push_back(s);
+				});
 			}
 		}
 		else if (item.type == itSong)
 			result.push_back(*item.song);
 		else if (item.type == itPlaylist)
 		{
-			auto list = Mpd.GetPlaylistContent(item.name);
-			result.insert(result.end(), list.begin(), list.end());
+			Mpd.GetPlaylistContent(item.name, [&result](MPD::Song &&s) {
+				result.push_back(s);
+			});
 		}
 	};
 	for (auto it = w.begin(); it != w.end(); ++it)
@@ -395,7 +397,9 @@ void Browser::GetDirectory(std::string dir, std::string subdir)
 	if (isLocal())
 		GetLocalDirectory(list);
 	else
-		list = Mpd.GetDirectory(dir);
+		Mpd.GetDirectory(dir, [&list](MPD::Item &&item) {
+			list.push_back(item);
+		});
 #	else
 	list = Mpd.GetDirectory(dir);
 #	endif // !WIN32
diff --git a/src/media_library.cpp b/src/media_library.cpp
index a18e028e..141a56ac 100644
--- a/src/media_library.cpp
+++ b/src/media_library.cpp
@@ -324,9 +324,9 @@ void MediaLibrary::update()
 				Mpd.AddSearch(Config.media_lib_primary_tag,
 				              Tags.current().value().tag());
 				Mpd.AddSearch(MPD_TAG_ALBUM, album);
-				auto dates = Mpd.CommitSearchTags();
-				for (auto date = dates.begin(); date != dates.end(); ++date)
-					Albums.addItem(SearchConstraints(album, *date, mtime));
+				Mpd.CommitSearchTags([this, &album, &mtime](std::string &&date) {
+					Albums.addItem(SearchConstraints(album, date, mtime));
+				});
 			}
 			else
 				Albums.addItem(SearchConstraints(album, "", mtime));
@@ -347,7 +347,10 @@ void MediaLibrary::update()
 		Albums << NC::XY(0, 0) << "Fetching albums...";
 		Albums.Window::refresh();
 		Mpd.BlockIdle(true);
-		auto artists = Mpd.GetList(Config.media_lib_primary_tag);
+		MPD::StringList artists;
+		Mpd.GetList(Config.media_lib_primary_tag, [&artists](std::string &&artist) {
+			artists.push_back(artist);
+		});
 		for (auto artist = artists.begin(); artist != artists.end(); ++artist)
 		{
 			Mpd.StartFieldSearchMTime(MPD_TAG_ALBUM, Config.media_library_sort_by_mtime);
@@ -364,9 +367,9 @@ void MediaLibrary::update()
 						Mpd.StartFieldSearch(MPD_TAG_DATE);
 						Mpd.AddSearch(Config.media_lib_primary_tag, *artist);
 						Mpd.AddSearch(MPD_TAG_ALBUM, album);
-						auto dates = Mpd.CommitSearchTags();
-						for (auto date = dates.begin(); date != dates.end(); ++date)
-							Albums.addItem(SearchConstraints(*artist, album, *date, mtime));
+						Mpd.CommitSearchTags([this, &artist, &album, &mtime](std::string &&date) {
+							Albums.addItem(SearchConstraints(*artist, album, date, mtime));
+						});
 					}
 					else
 						Albums.addItem(SearchConstraints(*artist, album, *artist, mtime));
@@ -403,9 +406,9 @@ void MediaLibrary::update()
 			if (Config.media_library_display_date)
 				Mpd.AddSearch(MPD_TAG_DATE, Albums.current().value().Date);
 		}
-		auto songs = Mpd.CommitSearchSongs();
-		for (auto s = songs.begin(); s != songs.end(); ++s)
-			Songs.addItem(*s, myPlaylist->checkForSong(*s));
+		Mpd.CommitSearchSongs([this](MPD::Song &&s) {
+			Songs.addItem(s, myPlaylist->checkForSong(s));
+		});
 		
 		if (Albums.current().value().Date == AllTracksMarker)
 			std::sort(Songs.beginV(), Songs.endV(), SortAllTracks());
@@ -675,9 +678,9 @@ MPD::SongList MediaLibrary::getSelectedSongs()
 		auto tag_handler = [&result](const std::string &tag) {
 			Mpd.StartSearch(true);
 			Mpd.AddSearch(Config.media_lib_primary_tag, tag);
-			auto songs = Mpd.CommitSearchSongs();
-			std::sort(songs.begin(), songs.end(), SortAllTracks());
-			result.insert(result.end(), songs.begin(), songs.end());
+			Mpd.CommitSearchSongs([&result](MPD::Song &&s) {
+				result.push_back(s);
+			});
 		};
 		for (auto it = Tags.begin(); it != Tags.end(); ++it)
 			if (it->isSelected())
@@ -701,9 +704,11 @@ MPD::SongList MediaLibrary::getSelectedSongs()
 					              Tags.current().value().tag());
 				Mpd.AddSearch(MPD_TAG_ALBUM, sc.Album);
 				Mpd.AddSearch(MPD_TAG_DATE, sc.Date);
-				auto songs = Mpd.CommitSearchSongs();
-				std::sort(songs.begin(), songs.end(), SortSongsByTrack);
-				result.insert(result.end(), songs.begin(), songs.end());
+				size_t begin = result.size();
+				Mpd.CommitSearchSongs([&result](MPD::Song &&s) {
+					result.push_back(s);
+				});
+				std::sort(result.begin()+begin, result.end(), SortSongsByTrack);
 			}
 		}
 		// if no item is selected, add songs from right column
diff --git a/src/mpdpp.cpp b/src/mpdpp.cpp
index aa099277..3d1b5ddc 100644
--- a/src/mpdpp.cpp
+++ b/src/mpdpp.cpp
@@ -663,19 +663,17 @@ bool Connection::Rename(const std::string &from, const std::string &to)
 	}
 }
 
-SongList Connection::GetPlaylistChanges(unsigned version)
+void Connection::GetPlaylistChanges(unsigned version, SongConsumer f)
 {
-	SongList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_send_queue_changes_meta(itsConnection, version);
 	while (mpd_song *s = mpd_recv_song(itsConnection))
-		result.push_back(Song(s));
+		f(Song(s));
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 Song Connection::GetSong(const std::string &path)
@@ -706,19 +704,17 @@ Song Connection::GetCurrentlyPlayingSong()
 	return result;
 }
 
-SongList Connection::GetPlaylistContent(const std::string &path)
+void Connection::GetPlaylistContent(const std::string &path, SongConsumer f)
 {
-	SongList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_send_list_playlist_meta(itsConnection, path.c_str());
 	while (mpd_song *s = mpd_recv_song(itsConnection))
-		result.push_back(Song(s));
+		f(Song(s));
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 void Connection::GetSupportedExtensions(std::set<std::string> &acc)
@@ -944,7 +940,10 @@ bool Connection::AddRandomTag(mpd_tag_type tag, size_t number)
 		return false;
 	assert(!isCommandsListEnabled);
 	
-	auto tags = GetList(tag);
+	StringList tags;
+	GetList(tag, [&tags](std::string &&tag_name) {
+		tags.push_back(tag_name);
+	});
 	if (number > tags.size())
 	{
 		if (itsErrorHandler)
@@ -959,7 +958,10 @@ bool Connection::AddRandomTag(mpd_tag_type tag, size_t number)
 		{
 			StartSearch(1);
 			AddSearch(tag, *it++);
-			auto songs = CommitSearchSongs();
+			SongList songs;
+			CommitSearchSongs([&songs](MPD::Song &&s) {
+				songs.push_back(s);
+			});
 			StartCommandsList();
 			for (auto s = songs.begin(); s != songs.end(); ++s)
 				AddSong(*s);
@@ -1110,35 +1112,31 @@ int Connection::SavePlaylist(const std::string &name)
 		return CheckForErrors();
 }
 
-StringList Connection::GetPlaylists()
+void Connection::GetPlaylists(StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
-	auto items = GetDirectory("/");
-	for (auto it = items.begin(); it != items.end(); ++it)
-		if (it->type == itPlaylist)
-			result.push_back(it->name);
-	return result;
+		return;
+	GetDirectory("/", [&f](Item &&item) {
+		if (item.type == itPlaylist)
+			f(std::move(item.name));
+	});
 }
 
-StringList Connection::GetList(mpd_tag_type type)
+void Connection::GetList(mpd_tag_type type, StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_search_db_tags(itsConnection, type);
 	mpd_search_commit(itsConnection);
 	while (mpd_pair *item = mpd_recv_pair_tag(itsConnection, type))
 	{
-		result.push_back(item->value);
+		f(std::string(item->value));
 		mpd_return_pair(itsConnection, item);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 TagMTimeList Connection::GetListMTime(mpd_tag_type type, bool get_mtime)
@@ -1237,37 +1235,33 @@ void Connection::AddSearchURI(const std::string &str) const
 		mpd_search_add_uri_constraint(itsConnection, MPD_OPERATOR_DEFAULT, str.c_str());
 }
 
-SongList Connection::CommitSearchSongs()
+void Connection::CommitSearchSongs(SongConsumer f)
 {
-	SongList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_search_commit(itsConnection);
 	while (mpd_song *s = mpd_recv_song(itsConnection))
-		result.push_back(Song(s));
+		f(Song(s));
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-StringList Connection::CommitSearchTags()
+void Connection::CommitSearchTags(StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_search_commit(itsConnection);
 	while (mpd_pair *tag = mpd_recv_pair_tag(itsConnection, itsSearchedField))
 	{
-		result.push_back(tag->value);
+		f(std::string(tag->value));
 		mpd_return_pair(itsConnection, tag);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 TagMTimeList Connection::CommitSearchTagsMTime()
@@ -1314,14 +1308,13 @@ TagMTimeList Connection::CommitSearchTagsMTime()
 	return result;
 }
 
-ItemList Connection::GetDirectory(const std::string &path)
+void Connection::GetDirectory(const std::string &directory, ItemConsumer f)
 {
-	ItemList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
-	mpd_send_list_meta(itsConnection, path.c_str());
+	mpd_send_list_meta(itsConnection, directory.c_str());
 	while (mpd_entity *item = mpd_recv_entity(itsConnection))
 	{
 		Item it;
@@ -1343,77 +1336,68 @@ ItemList Connection::GetDirectory(const std::string &path)
 				assert(false);
 		}
 		mpd_entity_free(item);
-		result.push_back(std::move(it));
+		f(std::move(it));
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-SongList Connection::GetDirectoryRecursive(const std::string &path)
+void Connection::GetDirectoryRecursive(const std::string &directory, SongConsumer f)
 {
-	SongList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
-	mpd_send_list_all_meta(itsConnection, path.c_str());
+	mpd_send_list_all_meta(itsConnection, directory.c_str());
 	while (mpd_song *s = mpd_recv_song(itsConnection))
-		result.push_back(Song(s));
+		f(Song(s));
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-StringList Connection::GetDirectories(const std::string &path)
+void Connection::GetDirectories(const std::string &directory, StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
-	mpd_send_list_meta(itsConnection, path.c_str());
+	mpd_send_list_meta(itsConnection, directory.c_str());
 	while (mpd_directory *dir = mpd_recv_directory(itsConnection))
 	{
-		result.push_back(mpd_directory_get_path(dir));
+		f(std::string(mpd_directory_get_path(dir)));
 		mpd_directory_free(dir);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-SongList Connection::GetSongs(const std::string &path)
+void Connection::GetSongs(const std::string &directory, SongConsumer f)
 {
-	SongList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
-	mpd_send_list_meta(itsConnection, path.c_str());
+	mpd_send_list_meta(itsConnection, directory.c_str());
 	while (mpd_song *s = mpd_recv_song(itsConnection))
-		result.push_back(Song(s));
+		f(Song(s));
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-OutputList Connection::GetOutputs()
+void Connection::GetOutputs(OutputConsumer f)
 {
-	OutputList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_send_outputs(itsConnection);
 	while (mpd_output *output = mpd_recv_output(itsConnection))
 	{
-		result.push_back(Output(mpd_output_get_name(output), mpd_output_get_enabled(output)));
+		f(Output(mpd_output_get_name(output), mpd_output_get_enabled(output)));
 		mpd_output_free(output);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 bool Connection::EnableOutput(int id)
@@ -1448,40 +1432,36 @@ bool Connection::DisableOutput(int id)
 	}
 }
 
-StringList Connection::GetURLHandlers()
+void Connection::GetURLHandlers(StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_send_list_url_schemes(itsConnection);
 	while (mpd_pair *handler = mpd_recv_pair_named(itsConnection, "handler"))
 	{
-		result.push_back(handler->value);
+		f(std::string(handler->value));
 		mpd_return_pair(itsConnection, handler);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
-StringList Connection::GetTagTypes()
+void Connection::GetTagTypes(StringConsumer f)
 {
-	StringList result;
 	if (!itsConnection)
-		return result;
+		return;
 	assert(!isCommandsListEnabled);
 	GoBusy();
 	mpd_send_list_tag_types(itsConnection);
 	while (mpd_pair *tag_type = mpd_recv_pair_named(itsConnection, "tagtype"))
 	{
-		result.push_back(tag_type->value);
+		f(std::string(tag_type->value));
 		mpd_return_pair(itsConnection, tag_type);
 	}
 	mpd_response_finish(itsConnection);
 	GoIdle();
-	return result;
 }
 
 int Connection::CheckForErrors()
diff --git a/src/mpdpp.h b/src/mpdpp.h
index c099140d..f312a294 100644
--- a/src/mpdpp.h
+++ b/src/mpdpp.h
@@ -128,11 +128,14 @@ typedef std::vector<Output> OutputList;
 
 class Connection
 {
-	friend struct Statistics;
-	
 	typedef void (*StatusUpdater) (Connection *, StatusChanges, void *);
 	typedef void (*ErrorHandler) (Connection *, int, const char *, void *);
 	
+	typedef std::function<void(Item &&)> ItemConsumer;
+	typedef std::function<void(Output &&)> OutputConsumer;
+	typedef std::function<void(Song &&)> SongConsumer;
+	typedef std::function<void(std::string &&)> StringConsumer;
+	
 public:
 	Connection();
 	~Connection();
@@ -197,14 +200,14 @@ public:
 	unsigned GetBitrate() const { return itsCurrentStatus ? mpd_status_get_kbit_rate(itsCurrentStatus) : 0; }
 	
 	size_t GetPlaylistLength() const { return itsCurrentStatus ? mpd_status_get_queue_length(itsCurrentStatus) : 0; }
-	SongList GetPlaylistChanges(unsigned);
+	void GetPlaylistChanges(unsigned, SongConsumer f);
 	
 	const std::string &GetErrorMessage() const { return itsErrorMessage; }
 	
 	Song GetCurrentlyPlayingSong();
 	int GetCurrentSongPos() const;
 	Song GetSong(const std::string &);
-	SongList GetPlaylistContent(const std::string &);
+	void GetPlaylistContent(const std::string &name, SongConsumer f);
 	
 	void GetSupportedExtensions(std::set<std::string> &);
 	
@@ -246,28 +249,26 @@ public:
 	void AddSearch(mpd_tag_type, const std::string &) const;
 	void AddSearchAny(const std::string &str) const;
 	void AddSearchURI(const std::string &str) const;
-	SongList CommitSearchSongs();
-	StringList CommitSearchTags();
+	void CommitSearchSongs(SongConsumer f);
+	void CommitSearchTags(StringConsumer f);
 	TagMTimeList CommitSearchTagsMTime();
 	
-	StringList GetPlaylists();
-	StringList GetList(mpd_tag_type);
+	void GetPlaylists(StringConsumer f);
+	void GetList(mpd_tag_type type, StringConsumer f);
 	TagMTimeList GetListMTime(mpd_tag_type, bool);
-	ItemList GetDirectory(const std::string &);
-	SongList GetDirectoryRecursive(const std::string &);
-	SongList GetSongs(const std::string &);
-	StringList GetDirectories(const std::string &);
+	void GetDirectory(const std::string &directory, ItemConsumer f);
+	void GetDirectoryRecursive(const std::string &directory, SongConsumer f);
+	void GetSongs(const std::string &directory, SongConsumer f);
+	void GetDirectories(const std::string &directory, StringConsumer f);
 	
-	OutputList GetOutputs();
+	void GetOutputs(OutputConsumer f);
 	bool EnableOutput(int);
 	bool DisableOutput(int);
 	
-	StringList GetURLHandlers();
-	StringList GetTagTypes();
+	void GetURLHandlers(StringConsumer f);
+	void GetTagTypes(StringConsumer f);
 	
 private:
-	//void check
-	
 	void GoIdle();
 	int GoBusy();
 	
diff --git a/src/outputs.cpp b/src/outputs.cpp
index 287885ba..18741c2e 100644
--- a/src/outputs.cpp
+++ b/src/outputs.cpp
@@ -99,9 +99,9 @@ void Outputs::mouseButtonPressed(MEVENT me)
 void Outputs::FetchList()
 {
 	w.clear();
-	auto outputs = Mpd.GetOutputs();
-	for (auto o = outputs.begin(); o != outputs.end(); ++o)
-		w.addItem(*o, o->isEnabled());
+	Mpd.GetOutputs([this](MPD::Output &&output) {
+		w.addItem(output, output.isEnabled());
+	});
 	if (myScreen == this)
 		w.refresh();
 }
diff --git a/src/playlist_editor.cpp b/src/playlist_editor.cpp
index c125dbb0..690edc50 100644
--- a/src/playlist_editor.cpp
+++ b/src/playlist_editor.cpp
@@ -130,16 +130,18 @@ void PlaylistEditor::update()
 		playlistsUpdateRequested = false;
 		Playlists.clearSearchResults();
 		withUnfilteredMenuReapplyFilter(Playlists, [this]() {
-			auto list = Mpd.GetPlaylists();
-			std::sort(list.begin(), list.end(),
+			size_t idx = 0;
+			Mpd.GetPlaylists([this, &idx](std::string &&playlist) {
+				if (idx < Playlists.size())
+					Playlists[idx].value() = playlist;
+				else
+					Playlists.addItem(playlist);
+				++idx;
+			});
+			if (idx < Playlists.size())
+				Playlists.resizeList(idx);
+			std::sort(Playlists.beginV(), Playlists.endV(),
 				LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
-			auto playlist = list.begin();
-			if (Playlists.size() > list.size())
-				Playlists.resizeList(list.size());
-			for (auto it = Playlists.begin(); it != Playlists.end(); ++it, ++playlist)
-				it->value() = *playlist;
-			for (; playlist != list.end(); ++playlist)
-				Playlists.addItem(*playlist);
 		});
 		Playlists.refresh();
 	}
@@ -149,25 +151,27 @@ void PlaylistEditor::update()
 		contentUpdateRequested = false;
 		Content.clearSearchResults();
 		withUnfilteredMenuReapplyFilter(Content, [this]() {
-			auto list = Mpd.GetPlaylistContent(Playlists.current().value());
-			auto song = list.begin();
-			if (Content.size() > list.size())
-				Content.resizeList(list.size());
-			for (auto it = Content.begin(); it != Content.end(); ++it, ++song)
-			{
-				it->value() = *song;
-				it->setBold(myPlaylist->checkForSong(*song));
-			}
-			for (; song != list.end(); ++song)
-				Content.addItem(*song, myPlaylist->checkForSong(*song));
+			size_t idx = 0;
+			Mpd.GetPlaylistContent(Playlists.current().value(), [this, &idx](MPD::Song &&s) {
+				if (idx < Content.size())
+				{
+					Content[idx].value() = s;
+					Content[idx].setBold(myPlaylist->checkForSong(s));
+				}
+				else
+					Content.addItem(s, myPlaylist->checkForSong(s));
+				++idx;
+			});
+			if (idx < Content.size())
+				Content.resizeList(idx);
 			std::string title;
 			if (Config.titles_visibility)
 			{
 				title = "Playlist content";
 				title += " (";
-				title += unsignedLongIntTo<std::string>::apply(list.size());
+				title += unsignedLongIntTo<std::string>::apply(Content.size());
 				title += " item";
-				if (list.size() == 1)
+				if (Content.size() == 1)
 					title += ")";
 				else
 					title += "s)";
@@ -418,8 +422,9 @@ MPD::SongList PlaylistEditor::getSelectedSongs()
 			if (it->isSelected())
 			{
 				any_selected = true;
-				auto songs = Mpd.GetPlaylistContent(it->value());
-				result.insert(result.end(), songs.begin(), songs.end());
+				Mpd.GetPlaylistContent(it->value(), [&result](MPD::Song &&s) {
+					result.push_back(s);
+				});
 			}
 		}
 		// we don't check for empty result here as it's possible that
diff --git a/src/search_engine.cpp b/src/search_engine.cpp
index 12327a27..16b608d5 100644
--- a/src/search_engine.cpp
+++ b/src/search_engine.cpp
@@ -410,21 +410,19 @@ void SearchEngine::Search()
 			Mpd.AddSearch(MPD_TAG_DATE, itsConstraints[9]);
 		if (!itsConstraints[10].empty())
 			Mpd.AddSearch(MPD_TAG_COMMENT, itsConstraints[10]);
-		auto songs = Mpd.CommitSearchSongs();
-		for (auto s = songs.begin(); s != songs.end(); ++s)
-			w.addItem(*s);
+		Mpd.CommitSearchSongs([this](MPD::Song &&s) {
+			w.addItem(s);
+		});
 		return;
 	}
 	
 	MPD::SongList list;
 	if (Config.search_in_db)
-		list = Mpd.GetDirectoryRecursive("/");
+		Mpd.GetDirectoryRecursive("/", [&list](MPD::Song &&s) {
+			list.push_back(s);
+		});
 	else
-	{
-		list.reserve(myPlaylist->main().size());
-		for (auto s = myPlaylist->main().beginV(); s != myPlaylist->main().endV(); ++s)
-			list.push_back(*s);
-	}
+		list.insert(list.end(), myPlaylist->main().beginV(), myPlaylist->main().endV());
 	
 	bool any_found = 1;
 	bool found = 1;
diff --git a/src/sel_items_adder.cpp b/src/sel_items_adder.cpp
index a667e390..ec275992 100644
--- a/src/sel_items_adder.cpp
+++ b/src/sel_items_adder.cpp
@@ -198,16 +198,15 @@ void SelectedItemsAdder::populatePlaylistSelector(BaseScreen *old_screen)
 	// stored playlists don't support songs from outside of mpd database
 	if (old_screen != myBrowser || !myBrowser->isLocal())
 	{
-		auto playlists = Mpd.GetPlaylists();
-		std::sort(playlists.begin(), playlists.end(),
-			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
-		for (auto pl = playlists.begin(); pl != playlists.end(); ++pl)
-		{
-			m_playlist_selector.addItem(Component::Item::Type(*pl,
-				std::bind(&Self::addToExistingPlaylist, this, *pl)
+		size_t begin = m_playlist_selector.size();
+		Mpd.GetPlaylists([this](std::string &&playlist) {
+			m_playlist_selector.addItem(Component::Item::Type(playlist,
+				std::bind(&Self::addToExistingPlaylist, this, playlist)
 			));
-		}
-		if (!playlists.empty())
+		});
+		std::sort(m_playlist_selector.beginV()+begin, m_playlist_selector.endV(),
+			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
+		if (begin < m_playlist_selector.size())
 			m_playlist_selector.addSeparator();
 	}
 	m_playlist_selector.addItem(Component::Item::Type("Cancel",
diff --git a/src/server_info.cpp b/src/server_info.cpp
index a49e5362..762cb228 100644
--- a/src/server_info.cpp
+++ b/src/server_info.cpp
@@ -36,8 +36,12 @@ ServerInfo::ServerInfo()
 {
 	SetDimensions();
 	w = NC::Scrollpad((COLS-itsWidth)/2, (MainHeight-itsHeight)/2+MainStartY, itsWidth, itsHeight, "MPD server info", Config.main_color, Config.window_border);
-	itsURLHandlers = Mpd.GetURLHandlers();
-	itsTagTypes = Mpd.GetTagTypes();
+	Mpd.GetURLHandlers([this](std::string &&handler) {
+		itsURLHandlers.push_back(handler);
+	});
+	Mpd.GetTagTypes([this](std::string &&tag_type) {
+		itsTagTypes.push_back(tag_type);
+	});
 }
 
 void ServerInfo::switchTo()
diff --git a/src/status.cpp b/src/status.cpp
index 53f1e3be..db81dfec 100644
--- a/src/status.cpp
+++ b/src/status.cpp
@@ -141,21 +141,19 @@ void Status::Changes::playlist()
 			myPlaylist->main().resizeList(playlist_length);
 		}
 		
-		auto songs = Mpd.GetPlaylistChanges(Mpd.GetOldPlaylistID());
-		for (auto s = songs.begin(); s != songs.end(); ++s)
-		{
-			size_t pos = s->getPosition();
+		Mpd.GetPlaylistChanges(Mpd.GetOldPlaylistID(), [](MPD::Song &&s) {
+			size_t pos = s.getPosition();
 			if (pos < myPlaylist->main().size())
 			{
 				// if song's already in playlist, replace it with a new one
 				MPD::Song &old_s = myPlaylist->main()[pos].value();
 				myPlaylist->unregisterHash(old_s.getHash());
-				old_s = *s;
+				old_s = s;
 			}
 			else // otherwise just add it to playlist
-				myPlaylist->main().addItem(*s);
-			myPlaylist->registerHash(s->getHash());
-		}
+				myPlaylist->main().addItem(s);
+			myPlaylist->registerHash(s.getHash());
+		});
 	});
 	
 	if (Mpd.isPlaying())
diff --git a/src/tag_editor.cpp b/src/tag_editor.cpp
index 2e5b7cb6..2fea1ed0 100644
--- a/src/tag_editor.cpp
+++ b/src/tag_editor.cpp
@@ -226,39 +226,28 @@ void TagEditor::update()
 		Dirs->Window::clear();
 		Tags->clear();
 		
-		int highlightme = -1;
-		auto dirs = Mpd.GetDirectories(itsBrowsedDir);
-		std::sort(dirs.begin(), dirs.end(), LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
 		if (itsBrowsedDir != "/")
-		{
-			size_t slash = itsBrowsedDir.rfind("/");
-			std::string parent = slash != std::string::npos ? itsBrowsedDir.substr(0, slash) : "/";
-			Dirs->addItem(make_pair("..", parent));
-		}
+			Dirs->addItem(std::make_pair("..", getParentDirectory(itsBrowsedDir)));
 		else
 			Dirs->addItem(std::make_pair(".", "/"));
-		for (auto dir = dirs.begin(); dir != dirs.end(); ++dir)
-		{
-			size_t slash = dir->rfind("/");
-			std::string to_display = slash != std::string::npos ? dir->substr(slash+1) : *dir;
-			Dirs->addItem(make_pair(to_display, *dir));
-			if (*dir == itsHighlightedDir)
-				highlightme = Dirs->size()-1;
-		}
-		if (highlightme != -1)
-			Dirs->highlight(highlightme);
-		
+		Mpd.GetDirectories(itsBrowsedDir, [this](std::string &&directory) {
+			Dirs->addItem(std::make_pair(getBasename(directory), directory));
+			if (directory == itsHighlightedDir)
+				Dirs->highlight(Dirs->size()-1);
+		});
+		std::sort(Dirs->beginV()+1, Dirs->endV(),
+			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
 		Dirs->display();
 	}
 	
 	if (Tags->reallyEmpty())
 	{
 		Tags->reset();
-		auto songs = Mpd.GetSongs(Dirs->current().value().second);
-		std::sort(songs.begin(), songs.end(),
+		Mpd.GetSongs(Dirs->current().value().second, [this](MPD::Song &&s) {
+			Tags->addItem(s);
+		});
+		std::sort(Tags->beginV(), Tags->endV(),
 			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
-		for (auto s = songs.begin(); s != songs.end(); ++s)
-			Tags->addItem(*s);
 		Tags->refresh();
 	}
 	
@@ -279,8 +268,11 @@ void TagEditor::enterPressed()
 	
 	if (w == Dirs)
 	{
-		auto dirs = Mpd.GetDirectories(Dirs->current().value().second);
-		if (!dirs.empty())
+		bool has_subdirs = false;
+		Mpd.GetDirectories(Dirs->current().value().second, [&has_subdirs](std::string &&) {
+			has_subdirs = true;
+		});
+		if (has_subdirs)
 		{
 			itsHighlightedDir = itsBrowsedDir;
 			itsBrowsedDir = Dirs->current().value().second;
diff --git a/src/utility/comparators.h b/src/utility/comparators.h
index b5d0e2c9..5c8fccd7 100644
--- a/src/utility/comparators.h
+++ b/src/utility/comparators.h
@@ -22,6 +22,7 @@
 #define _UTILITY_COMPARATORS
 
 #include <string>
+#include "exec_item.h"
 #include "mpdpp.h"
 #include "settings.h"
 #include "menu.h"
@@ -57,6 +58,11 @@ public:
 	bool operator()(const std::pair<A, B> &a, const std::pair<A, B> &b) const {
 		return m_cmp(a.first, b.first) < 0;
 	}
+	
+	template <typename ItemT, typename FunT>
+	bool operator()(const ExecItem<ItemT, FunT> &a, const ExecItem<ItemT, FunT> &b) const {
+		return m_cmp(a.item(), b.item());
+	}
 };
 
 class LocaleBasedItemSorting
diff --git a/src/visualizer.cpp b/src/visualizer.cpp
index 8ebd2004..2c1e3611 100644
--- a/src/visualizer.cpp
+++ b/src/visualizer.cpp
@@ -217,11 +217,12 @@ void Visualizer::FindOutputID()
 	m_output_id = -1;
 	if (!Config.visualizer_output_name.empty())
 	{
-		size_t i = 0;
-		auto outputs = Mpd.GetOutputs();
-		for (auto o = outputs.begin(); o != outputs.end(); ++o, ++i)
-			if (o->name() == Config.visualizer_output_name)
-				m_output_id = i;
+		size_t idx = 0;
+		Mpd.GetOutputs([this, &idx](MPD::Output &&output) {
+			if (output.name() == Config.visualizer_output_name)
+				m_output_id = idx;
+			++idx;
+		});
 		if (m_output_id == -1)
 			Statusbar::msg("There is no output named \"%s\"", Config.visualizer_output_name.c_str());
 	}