use SongIterator

src/actions.cpp

@@ -1319,30 +1319,31 @@ void EditLibraryTag::run()
 	if (!new_tag.empty() && new_tag != myLibrary->Tags.current().value().tag())
 	{
 		Statusbar::print("Updating tags...");
-		Mpd.StartSearch(1);
+		Mpd.StartSearch(true);
 		Mpd.AddSearch(Config.media_lib_primary_tag, myLibrary->Tags.current().value().tag());
 		MPD::MutableSong::SetFunction set = tagTypeToSetFunction(Config.media_lib_primary_tag);
 		assert(set);
 		bool success = true;
 		std::string dir_to_update;
-		Mpd.CommitSearchSongs([set, &dir_to_update, &new_tag, &success](MPD::Song s) {
-			if (!success)
-				return;
-			MPD::MutableSong ms = s;
+		for (MPD::SongIterator s = Mpd.CommitSearchSongs(), end; s != end; ++s)
+		{
+			MPD::MutableSong ms = std::move(*s);
 			ms.setTags(set, new_tag, Config.tags_separator);
 			Statusbar::printf("Updating tags in \"%1%\"...", ms.getName());
 			std::string path = Config.mpd_music_dir + ms.getURI();
 			if (!Tags::write(ms))
 			{
+				success = false;
 				const char msg[] = "Error while updating tags in \"%1%\"";
 				Statusbar::printf(msg, wideShorten(ms.getURI(), COLS-const_strlen(msg)));
-				success = false;
+				s.finish();
+				break;
 			}
 			if (dir_to_update.empty())
-				dir_to_update = s.getURI();
+				dir_to_update = ms.getURI();
 			else
-				dir_to_update = getSharedDirectory(dir_to_update, s.getURI());
-		});
+				dir_to_update = getSharedDirectory(dir_to_update, ms.getURI());
+		};
 		if (success)
 		{
 			Mpd.UpdateDirectory(dir_to_update);

src/browser.cpp

@@ -139,8 +139,10 @@ void Browser::enterPressed()
 		}
 		case itPlaylist:
 		{
-			MPD::SongList list;
-			Mpd.GetPlaylistContentNoInfo(item.name, vectorMoveInserter(list));
+			MPD::SongList list(
+				std::make_move_iterator(Mpd.GetPlaylistContentNoInfo(item.name)),
+				std::make_move_iterator(MPD::SongIterator())
+			);
 			bool success = addSongsToPlaylist(list.begin(), list.end(), true, -1);
 			Statusbar::printf("Playlist \"%1%\" loaded%2%",
 				item.name, withErrors(success)
@@ -366,7 +368,11 @@ MPD::SongList Browser::getSelectedSongs()
 			result.push_back(*item.song);
 		else if (item.type == itPlaylist)
 		{
-			Mpd.GetPlaylistContent(item.name, vectorMoveInserter(result));
+			std::copy(
+				std::make_move_iterator(Mpd.GetPlaylistContent(item.name)),
+				std::make_move_iterator(MPD::SongIterator()),
+				std::back_inserter(result)
+			);
 		}
 	};
 	for (auto it = w.begin(); it != w.end(); ++it)

src/media_library.cpp

@@ -350,14 +350,15 @@ void MediaLibrary::update()
 			Mpd.StartSearch(true);
 			Mpd.AddSearch(Config.media_lib_primary_tag, primary_tag);
 			std::map<std::tuple<std::string, std::string>, time_t> albums;
-			Mpd.CommitSearchSongs([&albums](MPD::Song s) {
-				auto key = std::make_tuple(s.getAlbum(), s.getDate());
+			for (MPD::SongIterator s = Mpd.CommitSearchSongs(), end; s != end; ++s)
+			{
+				auto key = std::make_tuple(s->getAlbum(), s->getDate());
 				auto it = albums.find(key);
 				if (it == albums.end())
-					albums[key] = s.getMTime();
+					albums[key] = s->getMTime();
 				else
-					it->second = s.getMTime();
-			});
+					it->second = s->getMTime();
+			};
 			withUnfilteredMenuReapplyFilter(Albums, [this, &albums, &primary_tag]() {
 				size_t idx = 0;
 				for (auto it = albums.begin(); it != albums.end(); ++it, ++idx)
@@ -404,17 +405,17 @@ void MediaLibrary::update()
 		}
 		withUnfilteredMenuReapplyFilter(Songs, [this, &album]() {
 			size_t idx = 0;
-			Mpd.CommitSearchSongs([this, &idx](MPD::Song s) {
-				bool is_playlist = myPlaylist->checkForSong(s);
+			for (MPD::SongIterator s = Mpd.CommitSearchSongs(), end; s != end; ++s, ++idx)
+			{
+				bool is_playlist = myPlaylist->checkForSong(*s);
 				if (idx < Songs.size())
 				{
-					Songs[idx].value() = s;
+					Songs[idx].value() = std::move(*s);
 					Songs[idx].setBold(is_playlist);
 				}
 				else
-					Songs.addItem(s, is_playlist);
-				++idx;
-			});
+					Songs.addItem(std::move(*s), is_playlist);
+			};
 			if (idx < Songs.size())
 				Songs.resizeList(idx);
 			std::sort(Songs.begin(), Songs.end(), SortSongs(!album.isAllTracksEntry()));
@@ -738,7 +739,11 @@ MPD::SongList MediaLibrary::getSelectedSongs()
 		auto tag_handler = [&result](const std::string &tag) {
 			Mpd.StartSearch(true);
 			Mpd.AddSearch(Config.media_lib_primary_tag, tag);
-			Mpd.CommitSearchSongs(vectorMoveInserter(result));
+			std::copy(
+				std::make_move_iterator(Mpd.CommitSearchSongs()),
+				std::make_move_iterator(MPD::SongIterator()),
+				std::back_inserter(result)
+			);
 		};
 		bool any_selected = false;
 		for (auto &e : Tags)
@@ -771,7 +776,11 @@ MPD::SongList MediaLibrary::getSelectedSongs()
 					Mpd.AddSearch(MPD_TAG_ALBUM, sc.entry().album());
 				Mpd.AddSearch(MPD_TAG_DATE, sc.entry().date());
 				size_t begin = result.size();
-				Mpd.CommitSearchSongs(vectorMoveInserter(result));
+				std::copy(
+					std::make_move_iterator(Mpd.CommitSearchSongs()),
+					std::make_move_iterator(MPD::SongIterator()),
+					std::back_inserter(result)
+				);
 				std::sort(result.begin()+begin, result.end(), SortSongs(false));
 			}
 		}
@@ -1046,10 +1055,12 @@ void MediaLibrary::AddToPlaylist(bool add_n_play)
 		if ((!Tags.empty() && isActiveWindow(Tags))
 		||  (isActiveWindow(Albums) && Albums.current().value().isAllTracksEntry()))
 		{
-			MPD::SongList list;
 			Mpd.StartSearch(true);
 			Mpd.AddSearch(Config.media_lib_primary_tag, Tags.current().value().tag());
-			Mpd.CommitSearchSongs(vectorMoveInserter(list));
+			MPD::SongList list(
+				std::make_move_iterator(Mpd.CommitSearchSongs()),
+				std::make_move_iterator(MPD::SongIterator())
+			);
 			bool success = addSongsToPlaylist(list.begin(), list.end(), add_n_play, -1);
 			std::string tag_type = boost::locale::to_lower(
 				tagTypeToString(Config.media_lib_primary_tag));

src/mpdpp.cpp

@@ -33,37 +33,43 @@ namespace MPD {
 
 SongIterator::~SongIterator()
 {
-	// if iterator wasn't fully traversed, clean up
-	if (m_connection.get() != nullptr)
+	if (m_connection)
+		finish();
+}
+
+void SongIterator::finish()
+{
+	// clean up
+	assert(m_connection);
 	mpd_response_finish(m_connection.get());
+	m_song = Song();
+	m_connection = nullptr;
 }
 
-Song &SongIterator::operator*()
+Song &SongIterator::operator*() const
 {
-	assert(m_connection.get() != nullptr);
+	assert(m_connection);
 	assert(!m_song.empty());
-	return m_song;
+	// we could make m_song a pointer to a Song and dereference here,
+	// but it's retarded as Song itself is essentially wrapper to
+	// std::shared_ptr. on the other hand, we need constness for the
+	// iterator to be able to play along with std::move_iterator.
+	return const_cast<Song &>(m_song);
 }
 
-Song *SongIterator::operator->()
+Song *SongIterator::operator->() const
 {
-	assert(m_connection.get() != nullptr);
-	assert(!m_song.empty());
-	return &m_song;
+	return &**this;
 }
 
 SongIterator &SongIterator::operator++()
 {
-	assert(m_connection.get() != nullptr);
+	assert(m_connection);
 	mpd_song *s = mpd_recv_song(m_connection.get());
 	if (s != nullptr)
 		m_song = Song(s);
 	else
-	{
-		mpd_response_finish(m_connection.get());
-		m_song = Song();
-		m_connection = nullptr;
-	}
+		finish();
 	return *this;
 }
 
@@ -74,6 +80,13 @@ SongIterator SongIterator::operator++(int)
 	return it;
 }
 
+SongIterator::SongIterator(std::shared_ptr<mpd_connection> conn)
+: m_connection(std::move(conn))
+{
+	// get the first element
+	++*this;
+}
+
 Connection::Connection() : m_connection(nullptr),
 				m_command_list_active(false),
 				m_idle(false),
@@ -336,14 +349,12 @@ void Connection::Rename(const std::string &from, const std::string &to)
 	checkErrors();
 }
 
-void Connection::GetPlaylistChanges(unsigned version, SongConsumer f)
+SongIterator Connection::GetPlaylistChanges(unsigned version)
 {
 	prechecksNoCommandsList();
 	mpd_send_queue_changes_meta(m_connection.get(), version);
-	while (mpd_song *s = mpd_recv_song(m_connection.get()))
-		f(Song(s));
-	mpd_response_finish(m_connection.get());
 	checkErrors();
+	return SongIterator(m_connection);
 }
 
 Song Connection::GetCurrentSong()
@@ -366,24 +377,22 @@ Song Connection::GetSong(const std::string &path)
 	return Song(s);
 }
 
-void Connection::GetPlaylistContent(const std::string &path, SongConsumer f)
+SongIterator Connection::GetPlaylistContent(const std::string &path)
 {
 	prechecksNoCommandsList();
 	mpd_send_list_playlist_meta(m_connection.get(), path.c_str());
-	while (mpd_song *s = mpd_recv_song(m_connection.get()))
-		f(Song(s));
-	mpd_response_finish(m_connection.get());
+	SongIterator result(m_connection);
 	checkErrors();
+	return result;
 }
 
-void Connection::GetPlaylistContentNoInfo(const std::string &path, SongConsumer f)
+SongIterator Connection::GetPlaylistContentNoInfo(const std::string &path)
 {
 	prechecksNoCommandsList();
 	mpd_send_list_playlist(m_connection.get(), path.c_str());
-	while (mpd_song *s = mpd_recv_song(m_connection.get()))
-		f(Song(s));
-	mpd_response_finish(m_connection.get());
+	SongIterator result(m_connection);
 	checkErrors();
+	return result;
 }
 
 void Connection::GetSupportedExtensions(std::set<std::string> &acc)
@@ -546,15 +555,15 @@ bool Connection::AddRandomTag(mpd_tag_type tag, size_t number)
 		auto it = tags.begin()+rand()%(tags.size()-number);
 		for (size_t i = 0; i < number && it != tags.end(); ++i)
 		{
-			StartSearch(1);
+			StartSearch(true);
 			AddSearch(tag, *it++);
-			SongList songs;
-			CommitSearchSongs([&songs](MPD::Song s) {
-				songs.push_back(s);
-			});
+			std::vector<std::string> paths;
+			MPD::SongIterator s = CommitSearchSongs(), end;
+			for (; s != end; ++s)
+				paths.push_back(s->getURI());
 			StartCommandsList();
-			for (auto s = songs.begin(); s != songs.end(); ++s)
-				AddSong(*s);
+			for (const auto &path : paths)
+				AddSong(path);
 			CommitCommandsList();
 		}
 	}
@@ -706,14 +715,12 @@ void Connection::AddSearchURI(const std::string &str) const
 	mpd_search_add_uri_constraint(m_connection.get(), MPD_OPERATOR_DEFAULT, str.c_str());
 }
 
-void Connection::CommitSearchSongs(SongConsumer f)
+SongIterator Connection::CommitSearchSongs()
 {
 	prechecksNoCommandsList();
 	mpd_search_commit(m_connection.get());
-	while (mpd_song *s = mpd_recv_song(m_connection.get()))
-		f(Song(s));
-	mpd_response_finish(m_connection.get());
 	checkErrors();
+	return SongIterator(m_connection);
 }
 
 void Connection::CommitSearchTags(StringConsumer f)
@@ -786,14 +793,12 @@ void Connection::GetDirectories(const std::string &directory, StringConsumer f)
 	checkErrors();
 }
 
-void Connection::GetSongs(const std::string &directory, SongConsumer f)
+SongIterator Connection::GetSongs(const std::string &directory)
 {
 	prechecksNoCommandsList();
 	mpd_send_list_meta(m_connection.get(), directory.c_str());
-	while (mpd_song *s = mpd_recv_song(m_connection.get()))
-		f(Song(s));
-	mpd_response_finish(m_connection.get());
 	checkErrors();
+	return SongIterator(m_connection);
 }
 
 void Connection::GetOutputs(OutputConsumer f)

src/mpdpp.h

@@ -152,8 +152,10 @@ struct SongIterator : std::iterator<std::forward_iterator_tag, Song>
 	SongIterator() : m_connection(nullptr) { }
 	~SongIterator();
 
-	Song &operator*();
-	Song *operator->();
+	void finish();
+
+	Song &operator*() const;
+	Song *operator->() const;
 
 	SongIterator &operator++();
 	SongIterator operator++(int);
@@ -167,7 +169,7 @@ struct SongIterator : std::iterator<std::forward_iterator_tag, Song>
 	}
 
 private:
-	SongIterator(std::shared_ptr<mpd_connection> conn) : m_connection(std::move(conn)) { }
+	SongIterator(std::shared_ptr<mpd_connection> conn);
 
 	std::shared_ptr<mpd_connection> m_connection;
 	Song m_song;
@@ -175,8 +177,6 @@ private:
 
 class Connection : private boost::noncopyable
 {
-	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;
@@ -221,12 +221,12 @@ public:
 	void Shuffle();
 	void ClearMainPlaylist();
 	
-	void GetPlaylistChanges(unsigned, SongConsumer f);
+	SongIterator GetPlaylistChanges(unsigned);
 	
 	Song GetCurrentSong();
 	Song GetSong(const std::string &);
-	void GetPlaylistContent(const std::string &name, SongConsumer f);
-	void GetPlaylistContentNoInfo(const std::string &name, SongConsumer f);
+	SongIterator GetPlaylistContent(const std::string &name);
+	SongIterator GetPlaylistContentNoInfo(const std::string &name);
 	
 	void GetSupportedExtensions(std::set<std::string> &);
 	
@@ -266,14 +266,14 @@ public:
 	void AddSearch(mpd_tag_type item, const std::string &str) const;
 	void AddSearchAny(const std::string &str) const;
 	void AddSearchURI(const std::string &str) const;
-	void CommitSearchSongs(SongConsumer f);
+	SongIterator CommitSearchSongs();
 	void CommitSearchTags(StringConsumer f);
 	
 	void GetPlaylists(StringConsumer f);
 	void GetList(mpd_tag_type type, StringConsumer f);
 	void GetDirectory(const std::string &directory, ItemConsumer f);
 	void GetDirectoryRecursive(const std::string &directory, SongConsumer f);
-	void GetSongs(const std::string &directory, SongConsumer f);
+	SongIterator GetSongs(const std::string &directory);
 	void GetDirectories(const std::string &directory, StringConsumer f);
 	
 	void GetOutputs(OutputConsumer f);

src/playlist_editor.cpp

@@ -167,16 +167,18 @@ void PlaylistEditor::update()
 			Content.clearSearchResults();
 			withUnfilteredMenuReapplyFilter(Content, [this]() {
 				size_t idx = 0;
-				Mpd.GetPlaylistContent(Playlists.current().value(), [this, &idx](MPD::Song s) {
+				MPD::SongIterator s = Mpd.GetPlaylistContent(Playlists.current().value()), end;
+				for (; s != end; ++s, ++idx)
+				{
+					bool is_bold = myPlaylist->checkForSong(*s);
 					if (idx < Content.size())
 					{
-						Content[idx].value() = s;
-						Content[idx].setBold(myPlaylist->checkForSong(s));
+						Content[idx].setBold(is_bold);
+						Content[idx].value() = std::move(*s);
 					}
 					else
-						Content.addItem(s, myPlaylist->checkForSong(s));
-					++idx;
-				});
+						Content.addItem(std::move(*s), is_bold);
+				}
 				if (idx < Content.size())
 					Content.resizeList(idx);
 				std::string title;
@@ -484,14 +486,18 @@ MPD::SongList PlaylistEditor::getSelectedSongs()
 			if (e.isSelected())
 			{
 				any_selected = true;
-				Mpd.GetPlaylistContent(e.value(), vectorMoveInserter(result));
+				std::copy(
+					std::make_move_iterator(Mpd.GetPlaylistContent(e.value())),
+					std::make_move_iterator(MPD::SongIterator()),
+					std::back_inserter(result)
+				);
 			}
 		}
 		// if no item is selected, add songs from right column
 		if (!any_selected && !Content.empty())
 		{
 			withUnfilteredMenu(Content, [this, &result]() {
-				result.insert(result.end(), Content.beginV(), Content.endV());
+				std::copy(Content.beginV(), Content.endV(), std::back_inserter(result));
 			});
 		}
 	}

src/search_engine.cpp

@@ -439,9 +439,8 @@ void SearchEngine::Search()
 			Mpd.AddSearch(MPD_TAG_DATE, itsConstraints[9]);
 		if (!itsConstraints[10].empty())
 			Mpd.AddSearch(MPD_TAG_COMMENT, itsConstraints[10]);
-		Mpd.CommitSearchSongs([this](MPD::Song s) {
-			w.addItem(s);
-		});
+		for (MPD::SongIterator s = Mpd.CommitSearchSongs(), end; s != end; ++s)
+			w.addItem(std::move(*s));
 		return;
 	}
 	

src/song.h

@@ -44,6 +44,14 @@ struct Song
 	
 	Song(mpd_song *s);
 
+	Song(const Song &rhs) : m_song(rhs.m_song), m_hash(rhs.m_hash) { }
+	Song(Song &&rhs) : m_song(std::move(rhs.m_song)), m_hash(rhs.m_hash) { }
+	Song &operator=(Song rhs) {
+		m_song = std::move(rhs.m_song);
+		m_hash = rhs.m_hash;
+		return *this;
+	}
+	
 	std::string get(mpd_tag_type type, unsigned idx = 0) const;
 	
 	virtual std::string getURI(unsigned idx = 0) const;

src/status.cpp

@@ -398,19 +398,21 @@ void Status::Changes::playlist(unsigned previous_version)
 			myPlaylist->main().resizeList(m_playlist_length);
 		}
 		
-		Mpd.GetPlaylistChanges(previous_version, [](MPD::Song s) {
-			size_t pos = s.getPosition();
+		MPD::SongIterator s = Mpd.GetPlaylistChanges(previous_version), end;
+		for (; s != end; ++s)
+		{
+			size_t pos = s->getPosition();
+			myPlaylist->registerSong(*s);
 			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->unregisterSong(old_s);
-				old_s = s;
+				old_s = std::move(*s);
 			}
 			else // otherwise just add it to playlist
-				myPlaylist->main().addItem(s);
-			myPlaylist->registerSong(s);
-		});
+				myPlaylist->main().addItem(std::move(*s));
+		}
 	});
 	
 	myPlaylist->reloadTotalLength();

src/tag_editor.cpp

@@ -252,9 +252,9 @@ void TagEditor::update()
 	if (Tags->reallyEmpty())
 	{
 		Tags->reset();
-		Mpd.GetSongs(Dirs->current().value().second, [this](MPD::Song s) {
-			Tags->addItem(s);
-		});
+		MPD::SongIterator s = Mpd.GetSongs(Dirs->current().value().second), end;
+		for (; s != end; ++s)
+			Tags->addItem(std::move(*s));
 		std::sort(Tags->beginV(), Tags->endV(),
 			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
 		Tags->refresh();