playlist/CloseSongEnumerator: new wrapper class

Simplifies a lot of code, because we don't need to return both the
SongEnumerator and the InputStream.

11 files changed, 111 insertions, 62 deletions

diff --git a/Makefile.am b/Makefile.am
index 374c09f52..19e4b255d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1150,6 +1150,8 @@ endif
 libplaylist_plugins_a_SOURCES = \
 	src/playlist/PlaylistPlugin.hxx \
 	src/playlist/SongEnumerator.hxx \
+	src/playlist/CloseSongEnumerator.cxx \
+	src/playlist/CloseSongEnumerator.hxx \
 	src/playlist/MemorySongEnumerator.cxx \
 	src/playlist/MemorySongEnumerator.hxx \
 	src/playlist/plugins/ExtM3uPlaylistPlugin.cxx \
diff --git a/src/playlist/CloseSongEnumerator.cxx b/src/playlist/CloseSongEnumerator.cxx
new file mode 100644
index 000000000..6a4042395
--- /dev/null
+++ b/src/playlist/CloseSongEnumerator.cxx
@@ -0,0 +1,34 @@
+/*
+ * 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 "CloseSongEnumerator.hxx"
+#include "input/InputStream.hxx"
+
+CloseSongEnumerator::~CloseSongEnumerator()
+{
+	delete other;
+	is->Close();
+}
+
+DetachedSong *
+CloseSongEnumerator::NextSong()
+{
+	return other->NextSong();
+}
diff --git a/src/playlist/CloseSongEnumerator.hxx b/src/playlist/CloseSongEnumerator.hxx
new file mode 100644
index 000000000..5a95cc28b
--- /dev/null
+++ b/src/playlist/CloseSongEnumerator.hxx
@@ -0,0 +1,47 @@
+/*
+ * 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_CLOSE_SONG_ENUMERATOR_HXX
+#define MPD_CLOSE_SONG_ENUMERATOR_HXX
+
+#include "SongEnumerator.hxx"
+#include "Compiler.h"
+
+struct InputStream;
+
+/**
+ * A #SongEnumerator wrapper that closes an #InputStream automatically
+ * after deleting the #SongEnumerator
+ */
+class CloseSongEnumerator final : public SongEnumerator {
+	SongEnumerator *const other;
+
+	InputStream *const is;
+
+public:
+	gcc_nonnull_all
+	CloseSongEnumerator(SongEnumerator *_other, InputStream *const _is)
+		:other(_other), is(_is) {}
+
+	virtual ~CloseSongEnumerator();
+
+	virtual DetachedSong *NextSong() override;
+};
+
+#endif
diff --git a/src/playlist/PlaylistAny.cxx b/src/playlist/PlaylistAny.cxx
index 04efbb569..671802e7d 100644
--- a/src/playlist/PlaylistAny.cxx
+++ b/src/playlist/PlaylistAny.cxx
@@ -21,6 +21,7 @@
 #include "PlaylistAny.hxx"
 #include "PlaylistMapper.hxx"
 #include "PlaylistRegistry.hxx"
+#include "CloseSongEnumerator.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
 #include "input/InputStream.hxx"
@@ -29,16 +30,13 @@
 #include <assert.h>
 
 static SongEnumerator *
-playlist_open_remote(const char *uri, Mutex &mutex, Cond &cond,
-		     InputStream **is_r)
+playlist_open_remote(const char *uri, Mutex &mutex, Cond &cond)
 {
 	assert(uri_has_scheme(uri));
 
 	SongEnumerator *playlist = playlist_list_open_uri(uri, mutex, cond);
-	if (playlist != nullptr) {
-		*is_r = nullptr;
+	if (playlist != nullptr)
 		return playlist;
-	}
 
 	Error error;
 	InputStream *is = InputStream::OpenReady(uri, mutex, cond, error);
@@ -55,15 +53,13 @@ playlist_open_remote(const char *uri, Mutex &mutex, Cond &cond,
 		return nullptr;
 	}
 
-	*is_r = is;
-	return playlist;
+	return new CloseSongEnumerator(playlist, is);
 }
 
 SongEnumerator *
-playlist_open_any(const char *uri, Mutex &mutex, Cond &cond,
-		  InputStream **is_r)
+playlist_open_any(const char *uri, Mutex &mutex, Cond &cond)
 {
 	return uri_has_scheme(uri)
-		? playlist_open_remote(uri, mutex, cond, is_r)
-		: playlist_mapper_open(uri, mutex, cond, is_r);
+		? playlist_open_remote(uri, mutex, cond)
+		: playlist_mapper_open(uri, mutex, cond);
 }
diff --git a/src/playlist/PlaylistAny.hxx b/src/playlist/PlaylistAny.hxx
index c472afb31..6ee792993 100644
--- a/src/playlist/PlaylistAny.hxx
+++ b/src/playlist/PlaylistAny.hxx
@@ -23,19 +23,13 @@
 class Mutex;
 class Cond;
 class SongEnumerator;
-struct InputStream;
 
 /**
  * Opens a playlist from the specified URI, which can be either an
  * absolute remote URI (with a scheme) or a relative path to the
  * music orplaylist directory.
- *
- * @param is_r on success, an input_stream object may be returned
- * here, which must be closed after the playlist_provider object is
- * freed
  */
 SongEnumerator *
-playlist_open_any(const char *uri, Mutex &mutex, Cond &cond,
-		  InputStream **is_r);
+playlist_open_any(const char *uri, Mutex &mutex, Cond &cond);
 
 #endif
diff --git a/src/playlist/PlaylistMapper.cxx b/src/playlist/PlaylistMapper.cxx
index ec32abd32..1211e892c 100644
--- a/src/playlist/PlaylistMapper.cxx
+++ b/src/playlist/PlaylistMapper.cxx
@@ -28,14 +28,11 @@
 #include <assert.h>
 
 static SongEnumerator *
-playlist_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
-		   InputStream **is_r)
+playlist_open_path(const char *path_fs, Mutex &mutex, Cond &cond)
 {
 	auto playlist = playlist_list_open_uri(path_fs, mutex, cond);
-	if (playlist != nullptr)
-		*is_r = nullptr;
-	else
-		playlist = playlist_list_open_path(path_fs, mutex, cond, is_r);
+	if (playlist == nullptr)
+		playlist = playlist_list_open_path(path_fs, mutex, cond);
 
 	return playlist;
 }
@@ -44,8 +41,7 @@ playlist_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
  * Load a playlist from the configured playlist directory.
  */
 static SongEnumerator *
-playlist_open_in_playlist_dir(const char *uri, Mutex &mutex, Cond &cond,
-			      InputStream **is_r)
+playlist_open_in_playlist_dir(const char *uri, Mutex &mutex, Cond &cond)
 {
 	assert(spl_valid_name(uri));
 
@@ -61,7 +57,7 @@ playlist_open_in_playlist_dir(const char *uri, Mutex &mutex, Cond &cond,
 		AllocatedPath::Build(playlist_directory_fs, uri_fs);
 	assert(!path_fs.IsNull());
 
-	return playlist_open_path(path_fs.c_str(), mutex, cond, is_r);
+	return playlist_open_path(path_fs.c_str(), mutex, cond);
 }
 
 #ifdef ENABLE_DATABASE
@@ -70,8 +66,7 @@ playlist_open_in_playlist_dir(const char *uri, Mutex &mutex, Cond &cond,
  * Load a playlist from the configured music directory.
  */
 static SongEnumerator *
-playlist_open_in_music_dir(const char *uri, Mutex &mutex, Cond &cond,
-			   InputStream **is_r)
+playlist_open_in_music_dir(const char *uri, Mutex &mutex, Cond &cond)
 {
 	assert(uri_safe_local(uri));
 
@@ -79,26 +74,24 @@ playlist_open_in_music_dir(const char *uri, Mutex &mutex, Cond &cond,
 	if (path.IsNull())
 		return nullptr;
 
-	return playlist_open_path(path.c_str(), mutex, cond, is_r);
+	return playlist_open_path(path.c_str(), mutex, cond);
 }
 
 #endif
 
 SongEnumerator *
-playlist_mapper_open(const char *uri, Mutex &mutex, Cond &cond,
-		     InputStream **is_r)
+playlist_mapper_open(const char *uri, Mutex &mutex, Cond &cond)
 {
 	if (spl_valid_name(uri)) {
-		auto playlist = playlist_open_in_playlist_dir(uri, mutex, cond,
-							      is_r);
+		auto playlist = playlist_open_in_playlist_dir(uri,
+							      mutex, cond);
 		if (playlist != nullptr)
 			return playlist;
 	}
 
 #ifdef ENABLE_DATABASE
 	if (uri_safe_local(uri)) {
-		auto playlist = playlist_open_in_music_dir(uri, mutex, cond,
-							   is_r);
+		auto playlist = playlist_open_in_music_dir(uri, mutex, cond);
 		if (playlist != nullptr)
 			return playlist;
 	}
diff --git a/src/playlist/PlaylistMapper.hxx b/src/playlist/PlaylistMapper.hxx
index a460cb124..01c982763 100644
--- a/src/playlist/PlaylistMapper.hxx
+++ b/src/playlist/PlaylistMapper.hxx
@@ -23,18 +23,12 @@
 class Mutex;
 class Cond;
 class SongEnumerator;
-struct InputStream;
 
 /**
  * Opens a playlist from an URI relative to the playlist or music
  * directory.
- *
- * @param is_r on success, an input_stream object may be returned
- * here, which must be closed after the playlist_provider object is
- * freed
  */
 SongEnumerator *
-playlist_mapper_open(const char *uri, Mutex &mutex, Cond &cond,
-		     InputStream **is_r);
+playlist_mapper_open(const char *uri, Mutex &mutex, Cond &cond);
 
 #endif
diff --git a/src/playlist/PlaylistQueue.cxx b/src/playlist/PlaylistQueue.cxx
index 9adea317f..85bf7ca72 100644
--- a/src/playlist/PlaylistQueue.cxx
+++ b/src/playlist/PlaylistQueue.cxx
@@ -22,9 +22,9 @@
 #include "PlaylistAny.hxx"
 #include "PlaylistSong.hxx"
 #include "Playlist.hxx"
-#include "input/InputStream.hxx"
 #include "SongEnumerator.hxx"
 #include "DetachedSong.hxx"
+#include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 #include "fs/Traits.hxx"
 
@@ -72,8 +72,7 @@ playlist_open_into_queue(const char *uri,
 	Mutex mutex;
 	Cond cond;
 
-	InputStream *is;
-	auto playlist = playlist_open_any(uri, mutex, cond, &is);
+	auto playlist = playlist_open_any(uri, mutex, cond);
 	if (playlist == nullptr)
 		return PlaylistResult::NO_SUCH_LIST;
 
@@ -82,9 +81,5 @@ playlist_open_into_queue(const char *uri,
 					 start_index, end_index,
 					 dest, pc, loader);
 	delete playlist;
-
-	if (is != nullptr)
-		is->Close();
-
 	return result;
 }
diff --git a/src/playlist/PlaylistRegistry.cxx b/src/playlist/PlaylistRegistry.cxx
index 55064849b..6b594e3c5 100644
--- a/src/playlist/PlaylistRegistry.cxx
+++ b/src/playlist/PlaylistRegistry.cxx
@@ -20,6 +20,7 @@
 #include "config.h"
 #include "PlaylistRegistry.hxx"
 #include "PlaylistPlugin.hxx"
+#include "CloseSongEnumerator.hxx"
 #include "plugins/ExtM3uPlaylistPlugin.hxx"
 #include "plugins/M3uPlaylistPlugin.hxx"
 #include "plugins/XspfPlaylistPlugin.hxx"
@@ -279,8 +280,7 @@ playlist_suffix_supported(const char *suffix)
 }
 
 SongEnumerator *
-playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
-			InputStream **is_r)
+playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond)
 {
 	const char *suffix;
 
@@ -301,7 +301,7 @@ playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
 
 	auto playlist = playlist_list_open_stream_suffix(*is, suffix);
 	if (playlist != nullptr)
-		*is_r = is;
+		playlist = new CloseSongEnumerator(playlist, is);
 	else
 		is->Close();
 
diff --git a/src/playlist/PlaylistRegistry.hxx b/src/playlist/PlaylistRegistry.hxx
index 0079fa68e..d8a24f4af 100644
--- a/src/playlist/PlaylistRegistry.hxx
+++ b/src/playlist/PlaylistRegistry.hxx
@@ -77,7 +77,6 @@ playlist_suffix_supported(const char *suffix);
  * @return a playlist, or nullptr on error
  */
 SongEnumerator *
-playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
-			InputStream **is_r);
+playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond);
 
 #endif
diff --git a/src/playlist/Print.cxx b/src/playlist/Print.cxx
index b5398e67d..5031a4b94 100644
--- a/src/playlist/Print.cxx
+++ b/src/playlist/Print.cxx
@@ -23,10 +23,10 @@
 #include "PlaylistSong.hxx"
 #include "SongEnumerator.hxx"
 #include "SongPrint.hxx"
-#include "input/InputStream.hxx"
 #include "DetachedSong.hxx"
 #include "SongLoader.hxx"
 #include "fs/Traits.hxx"
+#include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 
 static void
@@ -59,16 +59,11 @@ playlist_file_print(Client &client, const char *uri, bool detail)
 	Mutex mutex;
 	Cond cond;
 
-	InputStream *is;
-	SongEnumerator *playlist = playlist_open_any(uri, mutex, cond, &is);
+	SongEnumerator *playlist = playlist_open_any(uri, mutex, cond);
 	if (playlist == nullptr)
 		return false;
 
 	playlist_provider_print(client, uri, *playlist, detail);
 	delete playlist;
-
-	if (is != nullptr)
-		is->Close();
-
 	return true;
 }