/* * Copyright 2003-2017 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_DATABASE_INTERFACE_HXX #define MPD_DATABASE_INTERFACE_HXX #include "Visitor.hxx" #include "tag/Type.h" #include "util/Compiler.h" #include struct DatabasePlugin; struct DatabaseStats; struct DatabaseSelection; struct LightSong; class TagMask; 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. * * Throws #DatabaseError or std::runtime_error on error. */ virtual void Open() { } /** * Close the database, free allocated memory. */ virtual void Close() {} /** * Look up a song (including tag data) in the database. When * you don't need this anymore, call ReturnSong(). * * Throws std::runtime_error (or its derivative * #DatabaseError) on error. "Not found" is an error that * throws DatabaseErrorCode::NOT_FOUND. * * @param uri_utf8 the URI of the song within the music * directory (UTF-8) * @return a pointer that must be released with ReturnSong() */ virtual const LightSong *GetSong(const char *uri_utf8) const = 0; /** * Mark the song object as "unused". Call this on objects * returned by GetSong(). */ virtual void ReturnSong(const LightSong *song) const = 0; /** * Visit the selected entities. */ virtual void Visit(const DatabaseSelection &selection, VisitDirectory visit_directory, VisitSong visit_song, VisitPlaylist visit_playlist) const = 0; void Visit(const DatabaseSelection &selection, VisitDirectory visit_directory, VisitSong visit_song) const { Visit(selection, visit_directory, visit_song, VisitPlaylist()); } void Visit(const DatabaseSelection &selection, VisitSong visit_song) const { return Visit(selection, VisitDirectory(), visit_song); } /** * Visit all unique tag values. */ virtual void VisitUniqueTags(const DatabaseSelection &selection, TagType tag_type, TagMask group_mask, VisitTag visit_tag) const = 0; virtual DatabaseStats GetStats(const DatabaseSelection &selection) const = 0; /** * Update the database. * * Throws #std::runtime_error on error. * * @return the job id or 0 if not implemented */ virtual unsigned Update(gcc_unused const char *uri_utf8, gcc_unused bool discard) { /* not implemented: return 0 */ return 0; } /** * Returns the time stamp of the last database update. * Returns a negative value if that is not not known/available. */ gcc_pure virtual std::chrono::system_clock::time_point GetUpdateStamp() const noexcept = 0; }; #endif