playlist/Plugin: pass InputStreamPtr&& to open_stream()

Obsolete class CloseSongEnumerator, which was a kludge.

Makefile.am

@@ -1468,8 +1468,6 @@ 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 \

src/input/TextInputStream.cxx

@@ -26,6 +26,11 @@
 
 #include <assert.h>
 
+TextInputStream::TextInputStream(InputStreamPtr &&_is)
+	:is(std::move(_is)) {}
+
+TextInputStream::~TextInputStream() {}
+
 char *
 TextInputStream::ReadLine()
 {
@@ -54,7 +59,7 @@ TextInputStream::ReadLine()
 		--dest.size;
 
 		Error error;
-		size_t nbytes = is.LockRead(dest.data, dest.size, error);
+		size_t nbytes = is->LockRead(dest.data, dest.size, error);
 		if (nbytes > 0)
 			buffer.Append(nbytes);
 		else if (error.IsDefined()) {

src/input/TextInputStream.hxx

@@ -20,12 +20,13 @@
 #ifndef MPD_TEXT_INPUT_STREAM_HXX
 #define MPD_TEXT_INPUT_STREAM_HXX
 
+#include "input/Ptr.hxx"
 #include "util/StaticFifoBuffer.hxx"
 
 class InputStream;
 
 class TextInputStream {
-	InputStream &is;
+	InputStreamPtr is;
 	StaticFifoBuffer<char, 4096> buffer;
 
 public:
@@ -35,12 +36,16 @@ public:
 	 *
 	 * @param _is an open #InputStream object
 	 */
-	explicit TextInputStream(InputStream &_is)
+	explicit TextInputStream(InputStreamPtr &&_is);
-		:is(_is) {}
+	~TextInputStream();
 
 	TextInputStream(const TextInputStream &) = delete;
 	TextInputStream& operator=(const TextInputStream &) = delete;
 
+	InputStreamPtr &&StealInputStream() {
+		return std::move(is);
+	}
+
 	/**
 	 * Reads the next line from the stream with newline character stripped.
 	 *

src/playlist/CloseSongEnumerator.cxx

@@ -1,35 +0,0 @@
-/*
- * Copyright (C) 2003-2015 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"
-#include "DetachedSong.hxx"
-
-CloseSongEnumerator::~CloseSongEnumerator()
-{
-	delete other;
-	delete is;
-}
-
-std::unique_ptr<DetachedSong>
-CloseSongEnumerator::NextSong()
-{
-	return other->NextSong();
-}

src/playlist/CloseSongEnumerator.hxx

@@ -1,47 +0,0 @@
-/*
- * Copyright (C) 2003-2015 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"
-
-class 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 std::unique_ptr<DetachedSong> NextSong() override;
-};
-
-#endif

src/playlist/PlaylistPlugin.hxx

@@ -20,8 +20,9 @@
 #ifndef MPD_PLAYLIST_PLUGIN_HXX
 #define MPD_PLAYLIST_PLUGIN_HXX
 
+#include "input/Ptr.hxx"
+
 struct ConfigBlock;
-class InputStream;
 struct Tag;
 class Mutex;
 class Cond;
@@ -57,8 +58,11 @@ struct playlist_plugin {
 	 * Opens the playlist in the specified input stream.  It has
 	 * either matched one of the suffixes or one of the MIME
 	 * types.
+	 *
+	 * @parm is the input stream; the pointer will not be
+	 * invalidated when the function returns nullptr
 	 */
-	SongEnumerator *(*open_stream)(InputStream &is);
+	SongEnumerator *(*open_stream)(InputStreamPtr &&is);
 
 	const char *const*schemes;
 	const char *const*suffixes;
@@ -101,9 +105,9 @@ playlist_plugin_open_uri(const struct playlist_plugin *plugin, const char *uri,
 
 static inline SongEnumerator *
 playlist_plugin_open_stream(const struct playlist_plugin *plugin,
-			    InputStream &is)
+			    InputStreamPtr &&is)
 {
-	return plugin->open_stream(is);
+	return plugin->open_stream(std::move(is));
 }
 
 #endif

src/playlist/PlaylistRegistry.cxx

@@ -183,7 +183,7 @@ playlist_list_open_uri(const char *uri, Mutex &mutex, Cond &cond)
 }
 
 static SongEnumerator *
-playlist_list_open_stream_mime2(InputStream &is, const char *mime)
+playlist_list_open_stream_mime2(InputStreamPtr &&is, const char *mime)
 {
 	assert(mime != nullptr);
 
@@ -193,10 +193,10 @@ playlist_list_open_stream_mime2(InputStream &is, const char *mime)
 		    string_array_contains(plugin->mime_types, mime)) {
 			/* rewind the stream, so each plugin gets a
 			   fresh start */
-			is.Rewind(IgnoreError());
+			is->Rewind(IgnoreError());
 
 			auto playlist = playlist_plugin_open_stream(plugin,
-								    is);
+								    std::move(is));
 			if (playlist != nullptr)
 				return playlist;
 		}
@@ -206,24 +206,25 @@ playlist_list_open_stream_mime2(InputStream &is, const char *mime)
 }
 
 static SongEnumerator *
-playlist_list_open_stream_mime(InputStream &is, const char *full_mime)
+playlist_list_open_stream_mime(InputStreamPtr &&is, const char *full_mime)
 {
 	assert(full_mime != nullptr);
 
 	const char *semicolon = strchr(full_mime, ';');
 	if (semicolon == nullptr)
-		return playlist_list_open_stream_mime2(is, full_mime);
+		return playlist_list_open_stream_mime2(std::move(is),
+						       full_mime);
 
 	if (semicolon == full_mime)
 		return nullptr;
 
 	/* probe only the portion before the semicolon*/
 	const std::string mime(full_mime, semicolon);
-	return playlist_list_open_stream_mime2(is, mime.c_str());
+	return playlist_list_open_stream_mime2(std::move(is), mime.c_str());
 }
 
 SongEnumerator *
-playlist_list_open_stream_suffix(InputStream &is, const char *suffix)
+playlist_list_open_stream_suffix(InputStreamPtr &&is, const char *suffix)
 {
 	assert(suffix != nullptr);
 
@@ -233,9 +234,10 @@ playlist_list_open_stream_suffix(InputStream &is, const char *suffix)
 		    string_array_contains(plugin->suffixes, suffix)) {
 			/* rewind the stream, so each plugin gets a
 			   fresh start */
-			is.Rewind(IgnoreError());
+			is->Rewind(IgnoreError());
 
-			auto playlist = playlist_plugin_open_stream(plugin, is);
+			auto playlist = playlist_plugin_open_stream(plugin,
+								    std::move(is));
 			if (playlist != nullptr)
 				return playlist;
 		}
@@ -245,13 +247,14 @@ playlist_list_open_stream_suffix(InputStream &is, const char *suffix)
 }
 
 SongEnumerator *
-playlist_list_open_stream(InputStream &is, const char *uri)
+playlist_list_open_stream(InputStreamPtr &&is, const char *uri)
 {
-	assert(is.IsReady());
+	assert(is->IsReady());
 
-	const char *const mime = is.GetMimeType();
+	const char *const mime = is->GetMimeType();
 	if (mime != nullptr) {
-		auto playlist = playlist_list_open_stream_mime(is, mime);
+		auto playlist = playlist_list_open_stream_mime(std::move(is),
+							       mime);
 		if (playlist != nullptr)
 			return playlist;
 	}
@@ -261,7 +264,8 @@ playlist_list_open_stream(InputStream &is, const char *uri)
 		? uri_get_suffix(uri, suffix_buffer)
 		: nullptr;
 	if (suffix != nullptr) {
-		auto playlist = playlist_list_open_stream_suffix(is, suffix);
+		auto playlist = playlist_list_open_stream_suffix(std::move(is),
+								 suffix);
 		if (playlist != nullptr)
 			return playlist;
 	}

src/playlist/PlaylistRegistry.hxx

@@ -20,10 +20,11 @@
 #ifndef MPD_PLAYLIST_REGISTRY_HXX
 #define MPD_PLAYLIST_REGISTRY_HXX
 
+#include "input/Ptr.hxx"
+
 class Mutex;
 class Cond;
 class SongEnumerator;
-class InputStream;
 
 extern const struct playlist_plugin *const playlist_plugins[];
 
@@ -52,7 +53,7 @@ SongEnumerator *
 playlist_list_open_uri(const char *uri, Mutex &mutex, Cond &cond);
 
 SongEnumerator *
-playlist_list_open_stream_suffix(InputStream &is, const char *suffix);
+playlist_list_open_stream_suffix(InputStreamPtr &&is, const char *suffix);
 
 /**
  * Opens a playlist from an input stream.
@@ -62,7 +63,7 @@ playlist_list_open_stream_suffix(InputStream &is, const char *suffix);
  * used to select the appropriate playlist plugin
  */
 SongEnumerator *
-playlist_list_open_stream(InputStream &is, const char *uri);
+playlist_list_open_stream(InputStreamPtr &&is, const char *uri);
 
 /**
  * Determines if there is a playlist plugin which can handle the

src/playlist/PlaylistStream.cxx

@@ -20,7 +20,6 @@
 #include "config.h"
 #include "PlaylistStream.hxx"
 #include "PlaylistRegistry.hxx"
-#include "CloseSongEnumerator.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
 #include "input/InputStream.hxx"
@@ -50,12 +49,8 @@ try {
 		return nullptr;
 	}
 
-	auto playlist = playlist_list_open_stream_suffix(*is,
+	return playlist_list_open_stream_suffix(std::move(is),
 						suffix_utf8.c_str());
-	if (playlist != nullptr)
-		playlist = new CloseSongEnumerator(playlist, is.release());
-
-	return playlist;
 } catch (const std::runtime_error &e) {
 	LogError(e);
 	return nullptr;
@@ -97,11 +92,7 @@ try {
 		return nullptr;
 	}
 
-	playlist = playlist_list_open_stream(*is, uri);
+	return playlist_list_open_stream(std::move(is), uri);
-	if (playlist == nullptr)
-		return nullptr;
-
-	return new CloseSongEnumerator(playlist, is.release());
 } catch (const std::runtime_error &e) {
 	LogError(e);
 	return nullptr;

src/playlist/plugins/AsxPlaylistPlugin.cxx

@@ -144,7 +144,7 @@ asx_char_data(void *user_data, const XML_Char *s, int len)
  */
 
 static SongEnumerator *
-asx_open_stream(InputStream &is)
+asx_open_stream(InputStreamPtr &&is)
 {
 	AsxParser parser;
 
@@ -154,7 +154,7 @@ asx_open_stream(InputStream &is)
 		expat.SetCharacterDataHandler(asx_char_data);
 
 		Error error;
-		if (!expat.Parse(is, error)) {
+		if (!expat.Parse(*is, error)) {
 			LogError(error);
 			return nullptr;
 		}

src/playlist/plugins/CuePlaylistPlugin.cxx

@@ -27,22 +27,21 @@
 #include <string>
 
 class CuePlaylist final : public SongEnumerator {
-	InputStream &is;
 	TextInputStream tis;
 	CueParser parser;
 
  public:
-	CuePlaylist(InputStream &_is)
+	CuePlaylist(InputStreamPtr &&is)
-		:is(_is), tis(is) {
+		:tis(std::move(is)) {
 	}
 
 	virtual std::unique_ptr<DetachedSong> NextSong() override;
 };
 
 static SongEnumerator *
-cue_playlist_open_stream(InputStream &is)
+cue_playlist_open_stream(InputStreamPtr &&is)
 {
-	return new CuePlaylist(is);
+	return new CuePlaylist(std::move(is));
 }
 
 std::unique_ptr<DetachedSong>

src/playlist/plugins/ExtM3uPlaylistPlugin.cxx

@@ -27,6 +27,7 @@
 #include "util/StringUtil.hxx"
 #include "util/StringCompare.hxx"
 #include "input/TextInputStream.hxx"
+#include "input/InputStream.hxx"
 
 #include <string.h>
 #include <stdlib.h>
@@ -35,28 +36,36 @@ class ExtM3uPlaylist final : public SongEnumerator {
 	TextInputStream tis;
 
 public:
-	ExtM3uPlaylist(InputStream &is)
+	ExtM3uPlaylist(InputStreamPtr &&is)
-		:tis(is) {
+		:tis(std::move(is)) {
 	}
 
-	bool CheckFirstLine() {
+	/**
+	 * @return nullptr if ExtM3U was recognized, or the original
+	 * InputStream on error
+	 */
+	InputStreamPtr CheckFirstLine() {
 		char *line = tis.ReadLine();
 		if (line == nullptr)
-			return false;
+			return tis.StealInputStream();
 
 		StripRight(line);
-		return strcmp(line, "#EXTM3U") == 0;
+		if (strcmp(line, "#EXTM3U") != 0)
+			return tis.StealInputStream();
+
+		return nullptr;
 	}
 
 	virtual std::unique_ptr<DetachedSong> NextSong() override;
 };
 
 static SongEnumerator *
-extm3u_open_stream(InputStream &is)
+extm3u_open_stream(InputStreamPtr &&is)
 {
-	ExtM3uPlaylist *playlist = new ExtM3uPlaylist(is);
+	ExtM3uPlaylist *playlist = new ExtM3uPlaylist(std::move(is));
 
-	if (!playlist->CheckFirstLine()) {
+	is = playlist->CheckFirstLine();
+	if (is) {
 		/* no EXTM3U header: fall back to the plain m3u
 		   plugin */
 		delete playlist;

src/playlist/plugins/M3uPlaylistPlugin.cxx

@@ -29,17 +29,17 @@ class M3uPlaylist final : public SongEnumerator {
 	TextInputStream tis;
 
 public:
-	M3uPlaylist(InputStream &is)
+	M3uPlaylist(InputStreamPtr &&is)
-		:tis(is) {
+		:tis(std::move(is)) {
 	}
 
 	virtual std::unique_ptr<DetachedSong> NextSong() override;
 };
 
 static SongEnumerator *
-m3u_open_stream(InputStream &is)
+m3u_open_stream(InputStreamPtr &&is)
 {
-	return new M3uPlaylist(is);
+	return new M3uPlaylist(std::move(is));
 }
 
 std::unique_ptr<DetachedSong>

src/playlist/plugins/PlsPlaylistPlugin.cxx

@@ -22,6 +22,7 @@
 #include "../PlaylistPlugin.hxx"
 #include "../MemorySongEnumerator.hxx"
 #include "input/TextInputStream.hxx"
+#include "input/InputStream.hxx"
 #include "DetachedSong.hxx"
 #include "tag/TagBuilder.hxx"
 #include "util/ASCII.hxx"
@@ -142,17 +143,22 @@ ParsePls(TextInputStream &is, std::forward_list<DetachedSong> &songs)
 }
 
 static bool
-ParsePls(InputStream &is, std::forward_list<DetachedSong> &songs)
+ParsePls(InputStreamPtr &&is, std::forward_list<DetachedSong> &songs)
 {
-	TextInputStream tis(is);
+	TextInputStream tis(std::move(is));
-	return ParsePls(tis, songs);
+	if (!ParsePls(tis, songs)) {
+		is = tis.StealInputStream();
+		return false;
+	}
+
+	return true;
 }
 
 static SongEnumerator *
-pls_open_stream(InputStream &is)
+pls_open_stream(InputStreamPtr &&is)
 {
 	std::forward_list<DetachedSong> songs;
-	if (!ParsePls(is, songs))
+	if (!ParsePls(std::move(is), songs))
 		return nullptr;
 
 	return new MemorySongEnumerator(std::move(songs));

src/playlist/plugins/RssPlaylistPlugin.cxx

@@ -142,7 +142,7 @@ rss_char_data(void *user_data, const XML_Char *s, int len)
  */
 
 static SongEnumerator *
-rss_open_stream(InputStream &is)
+rss_open_stream(InputStreamPtr &&is)
 {
 	RssParser parser;
 
@@ -152,7 +152,7 @@ rss_open_stream(InputStream &is)
 		expat.SetCharacterDataHandler(rss_char_data);
 
 		Error error;
-		if (!expat.Parse(is, error)) {
+		if (!expat.Parse(*is, error)) {
 			LogError(error);
 			return nullptr;
 		}

src/playlist/plugins/XspfPlaylistPlugin.cxx

@@ -189,7 +189,7 @@ xspf_char_data(void *user_data, const XML_Char *s, int len)
  */
 
 static SongEnumerator *
-xspf_open_stream(InputStream &is)
+xspf_open_stream(InputStreamPtr &&is)
 {
 	XspfParser parser;
 
@@ -199,7 +199,7 @@ xspf_open_stream(InputStream &is)
 		expat.SetCharacterDataHandler(xspf_char_data);
 
 		Error error;
-		if (!expat.Parse(is, error)) {
+		if (!expat.Parse(*is, error)) {
 			LogError(error);
 			return nullptr;
 		}

test/dump_playlist.cxx

@@ -98,7 +98,7 @@ try {
 
 		/* open the playlist */
 
-		playlist = playlist_list_open_stream(*is, uri);
+		playlist = playlist_list_open_stream(std::move(is), uri);
 		if (playlist == NULL) {
 			fprintf(stderr, "Failed to open playlist\n");
 			return 2;

test/dump_text_file.cxx

@@ -44,23 +44,23 @@ dump_text_file(TextInputStream &is)
 }
 
 static int
-dump_input_stream(InputStream &is)
+dump_input_stream(InputStreamPtr &&is)
 {
 	{
-		TextInputStream tis(is);
+		TextInputStream tis(std::move(is));
 		dump_text_file(tis);
 	}
 
-	is.Lock();
+	is->Lock();
 
 	Error error;
-	if (!is.Check(error)) {
+	if (!is->Check(error)) {
 		LogError(error);
-		is.Unlock();
+		is->Unlock();
 		return EXIT_FAILURE;
 	}
 
-	is.Unlock();
+	is->Unlock();
 
 	return 0;
 }
@@ -98,7 +98,7 @@ int main(int argc, char **argv)
 
 		auto is = InputStream::OpenReady(argv[1], mutex, cond, error);
 		if (is) {
-			ret = dump_input_stream(*is);
+			ret = dump_input_stream(std::move(is));
 		} else {
 			if (error.IsDefined())
 				LogError(error);