DatabaseSong: new library merging duplicate code

Makefile.am

@@ -107,6 +107,7 @@ src_mpd_SOURCES = \
 	src/DirectorySave.cxx src/DirectorySave.hxx \
 	src/DatabaseSimple.hxx \
 	src/DatabaseGlue.cxx src/DatabaseGlue.hxx \
+	src/DatabaseSong.cxx src/DatabaseSong.hxx \
 	src/DatabasePrint.cxx src/DatabasePrint.hxx \
 	src/DatabaseQueue.cxx src/DatabaseQueue.hxx \
 	src/DatabasePlaylist.cxx src/DatabasePlaylist.hxx \

src/DatabaseSong.cxx

+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "DatabaseSong.hxx"
+#include "DatabaseGlue.hxx"
+#include "DatabasePlugin.hxx"
+#include "DetachedSong.hxx"
+
+DetachedSong *
+DatabaseDetachSong(const char *uri, Error &error)
+{
+	const Database *db = GetDatabase(error);
+	if (db == nullptr)
+		return nullptr;
+
+	Song *tmp = db->GetSong(uri, error);
+	if (tmp == nullptr)
+		return nullptr;
+
+	DetachedSong *song = new DetachedSong(*tmp);
+	db->ReturnSong(tmp);
+	return song;
+}

src/DatabaseSong.hxx

+/*
+ * 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_DATABASE_SONG_HXX
+#define MPD_DATABASE_SONG_HXX
+
+#include "Compiler.h"
+
+class DetachedSong;
+class Error;
+
+/**
+ * Look up a song in the database and convert it to a #DetachedSong
+ * instance.  The caller is responsible for freeing it.
+ *
+ * @return nullptr on error
+ */
+gcc_malloc gcc_nonnull_all
+DetachedSong *
+DatabaseDetachSong(const char *uri, Error &error);
+
+#endif

src/PlaylistEdit.cxx

@@ -32,8 +32,7 @@
 #include "Song.hxx"
 #include "DetachedSong.hxx"
 #include "Idle.hxx"
-#include "DatabaseGlue.hxx"
-#include "DatabasePlugin.hxx"
+#include "DatabaseSong.hxx"
 #include "Log.hxx"
 
 #include <stdlib.h>
@@ -113,16 +112,9 @@ playlist::AppendURI(PlayerControl &pc,
 	if (uri_has_scheme(uri)) {
 		song = new DetachedSong(uri);
 	} else {
-		const Database *db = GetDatabase();
-		if (db == nullptr)
+		song = DatabaseDetachSong(uri, IgnoreError());
+		if (song == nullptr)
 			return PlaylistResult::NO_SUCH_SONG;
-
-		Song *tmp = db->GetSong(uri, IgnoreError());
-		if (tmp == nullptr)
-			return PlaylistResult::NO_SUCH_SONG;
-
-		song = new DetachedSong(*tmp);
-		db->ReturnSong(tmp);
 	}
 
 	PlaylistResult result = AppendSong(pc, std::move(*song), added_id);

src/PlaylistFile.cxx

@@ -22,8 +22,7 @@
 #include "PlaylistSave.hxx"
 #include "PlaylistInfo.hxx"
 #include "PlaylistVector.hxx"
-#include "DatabasePlugin.hxx"
-#include "DatabaseGlue.hxx"
+#include "DatabaseSong.hxx"
 #include "DetachedSong.hxx"
 #include "Mapper.hxx"
 #include "fs/TextFile.hxx"
@@ -405,18 +404,13 @@ spl_append_uri(const char *url, const char *utf8file, Error &error)
 		return spl_append_song(utf8file, DetachedSong(url),
 				       error);
 	} else {
-		const Database *db = GetDatabase(error);
-		if (db == nullptr)
+		DetachedSong *song = DatabaseDetachSong(url, error);
+		if (song == nullptr)
 			return false;
 
-		Song *tmp = db->GetSong(url, error);
-		if (tmp == nullptr)
-			return false;
-
-		const DetachedSong song(*tmp);
-		db->ReturnSong(tmp);
-
-		return spl_append_song(utf8file, song, error);
+		bool success = spl_append_song(utf8file, *song, error);
+		delete song;
+		return success;
 	}
 }
 

src/PlaylistSong.cxx

@@ -20,8 +20,7 @@
 #include "config.h"
 #include "PlaylistSong.hxx"
 #include "Mapper.hxx"
-#include "DatabasePlugin.hxx"
-#include "DatabaseGlue.hxx"
+#include "DatabaseSong.hxx"
 #include "ls.hxx"
 #include "tag/Tag.hxx"
 #include "tag/TagBuilder.hxx"
@@ -106,17 +105,9 @@ playlist_check_load_song(const DetachedSong *song, const char *uri, bool secure)
 			return nullptr;
 		}
 	} else {
-		const Database *db = GetDatabase();
-		if (db == nullptr)
+		dest = DatabaseDetachSong(uri, IgnoreError());
+		if (dest == nullptr)
 			return nullptr;
-
-		Song *tmp = db->GetSong(uri, IgnoreError());
-		if (tmp == nullptr)
-			/* not found in database */
-			return nullptr;
-
-		dest = new DetachedSong(*tmp);
-		db->ReturnSong(tmp);
 	}
 
 	return apply_song_metadata(dest, song);