MusicPipe: expose the C++ API

src/DecoderAPI.cxx

@@ -164,7 +164,7 @@ decoder_command_finished(struct decoder *decoder)
 	if (decoder->initial_seek_running) {
 		assert(!decoder->seeking);
 		assert(decoder->chunk == NULL);
-		assert(music_pipe_empty(dc->pipe));
+		assert(dc->pipe->IsEmpty());
 
 		decoder->initial_seek_running = false;
 		decoder->timestamp = dc->start_ms / 1000.;
@@ -182,7 +182,7 @@ decoder_command_finished(struct decoder *decoder)
 			decoder->chunk = NULL;
 		}
 
-		music_pipe_clear(dc->pipe, dc->buffer);
+		dc->pipe->Clear(dc->buffer);
 
 		decoder->timestamp = dc->seek_where;
 	}

src/DecoderControl.cxx

@@ -105,12 +105,11 @@ decoder_control::IsCurrentSong(const Song *_song) const
 void
 decoder_control::Start(Song *_song,
 		       unsigned _start_ms, unsigned _end_ms,
-		       music_buffer *_buffer, music_pipe *_pipe)
+		       music_buffer *_buffer, MusicPipe &_pipe)
 {
 	assert(_song != NULL);
 	assert(_buffer != NULL);
-	assert(_pipe != NULL);
-	assert(music_pipe_empty(_pipe));
+	assert(_pipe.IsEmpty());
 
 	if (song != nullptr)
 		song->Free();
@@ -119,7 +118,7 @@ decoder_control::Start(Song *_song,
 	start_ms = _start_ms;
 	end_ms = _end_ms;
 	buffer = _buffer;
-	pipe = _pipe;
+	pipe = &_pipe;
 
 	dc_command(this, DECODE_COMMAND_START);
 }

src/DecoderControl.hxx

@@ -31,6 +31,7 @@
 #include <assert.h>
 
 struct Song;
+class MusicPipe;
 
 enum decoder_state {
 	DECODE_STATE_STOP = 0,
@@ -127,7 +128,7 @@ struct decoder_control {
 	 * The destination pipe for decoded chunks.  The caller thread
 	 * owns this object, and is responsible for freeing it.
 	 */
-	struct music_pipe *pipe;
+	MusicPipe *pipe;
 
 	float replay_gain_db;
 	float replay_gain_prev_db;
@@ -287,7 +288,7 @@ struct decoder_control {
 	 * the caller)
 	 */
 	void Start(Song *song, unsigned start_ms, unsigned end_ms,
-		   music_buffer *buffer, music_pipe *pipe);
+		   music_buffer *buffer, MusicPipe &pipe);
 
 	void Stop();
 

src/DecoderInternal.cxx

@@ -100,7 +100,7 @@ decoder_flush_chunk(struct decoder *decoder)
 	if (decoder->chunk->IsEmpty())
 		music_buffer_return(dc->buffer, decoder->chunk);
 	else
-		music_pipe_push(dc->pipe, decoder->chunk);
+		dc->pipe->Push(decoder->chunk);
 
 	decoder->chunk = NULL;
 }

src/MusicChunk.hxx

@@ -36,7 +36,7 @@ struct Tag;
 
 /**
  * A chunk of music data.  Its format is defined by the
- * music_pipe_append() caller.
+ * MusicPipe::Push() caller.
  */
 struct music_chunk {
 	/** the next chunk in a linked list */

src/MusicPipe.cxx

@@ -21,74 +21,15 @@
 #include "MusicPipe.hxx"
 #include "MusicBuffer.hxx"
 #include "MusicChunk.hxx"
-#include "thread/Mutex.hxx"
-
-#include <glib.h>
-
-#include <assert.h>
-
-struct music_pipe {
-	/** the first chunk */
-	struct music_chunk *head;
-
-	/** a pointer to the tail of the chunk */
-	struct music_chunk **tail_r;
-
-	/** the current number of chunks */
-	unsigned size;
-
-	/** a mutex which protects #head and #tail_r */
-	mutable Mutex mutex;
 
 #ifndef NDEBUG
-	AudioFormat audio_format;
-#endif
-
-	music_pipe()
-		:head(nullptr), tail_r(&head), size(0) {
-#ifndef NDEBUG
-		audio_format.Clear();
-#endif
-	}
-
-	~music_pipe() {
-		assert(head == nullptr);
-		assert(tail_r == &head);
-	}
-};
-
-struct music_pipe *
-music_pipe_new(void)
-{
-	return new music_pipe();
-}
-
-void
-music_pipe_free(struct music_pipe *mp)
-{
-	delete mp;
-}
-
-#ifndef NDEBUG
-
-bool
-music_pipe_check_format(const struct music_pipe *pipe,
-			const AudioFormat audio_format)
-{
-	assert(pipe != NULL);
-
-	return !pipe->audio_format.IsDefined() ||
-		pipe->audio_format == audio_format;
-}
 
 bool
-music_pipe_contains(const struct music_pipe *mp,
-		    const struct music_chunk *chunk)
+MusicPipe::Contains(const music_chunk *chunk) const
 {
-	const ScopeLock protect(mp->mutex);
+	const ScopeLock protect(mutex);
 
-	for (const struct music_chunk *i = mp->head;
-	     i != NULL; i = i->next)
+	for (const struct music_chunk *i = head; i != nullptr; i = i->next)
 		if (i == chunk)
 			return true;
 
@@ -97,40 +38,34 @@ music_pipe_contains(const struct music_pipe *mp,
 
 #endif
 
-const struct music_chunk *
-music_pipe_peek(const struct music_pipe *mp)
-{
-	return mp->head;
-}
-
-struct music_chunk *
-music_pipe_shift(struct music_pipe *mp)
+music_chunk *
+MusicPipe::Shift()
 {
-	const ScopeLock protect(mp->mutex);
+	const ScopeLock protect(mutex);
 
-	struct music_chunk *chunk = mp->head;
-	if (chunk != NULL) {
+	music_chunk *chunk = head;
+	if (chunk != nullptr) {
 		assert(!chunk->IsEmpty());
 
-		mp->head = chunk->next;
-		--mp->size;
+		head = chunk->next;
+		--size;
 
-		if (mp->head == NULL) {
-			assert(mp->size == 0);
-			assert(mp->tail_r == &chunk->next);
+		if (head == nullptr) {
+			assert(size == 0);
+			assert(tail_r == &chunk->next);
 
-			mp->tail_r = &mp->head;
+			tail_r = &head;
 		} else {
-			assert(mp->size > 0);
-			assert(mp->tail_r != &chunk->next);
+			assert(size > 0);
+			assert(tail_r != &chunk->next);
 		}
 
 #ifndef NDEBUG
 		/* poison the "next" reference */
-		chunk->next = (struct music_chunk *)(void *)0x01010101;
+		chunk->next = (music_chunk *)(void *)0x01010101;
 
-		if (mp->size == 0)
-			mp->audio_format.Clear();
+		if (size == 0)
+			audio_format.Clear();
 #endif
 	}
 
@@ -138,41 +73,34 @@ music_pipe_shift(struct music_pipe *mp)
 }
 
 void
-music_pipe_clear(struct music_pipe *mp, struct music_buffer *buffer)
+MusicPipe::Clear(music_buffer *buffer)
 {
-	struct music_chunk *chunk;
+	music_chunk *chunk;
 
-	while ((chunk = music_pipe_shift(mp)) != NULL)
+	while ((chunk = Shift()) != nullptr)
 		music_buffer_return(buffer, chunk);
 }
 
 void
-music_pipe_push(struct music_pipe *mp, struct music_chunk *chunk)
+MusicPipe::Push(music_chunk *chunk)
 {
 	assert(!chunk->IsEmpty());
 	assert(chunk->length == 0 || chunk->audio_format.IsValid());
 
-	const ScopeLock protect(mp->mutex);
+	const ScopeLock protect(mutex);
 
-	assert(mp->size > 0 || !mp->audio_format.IsDefined());
-	assert(!mp->audio_format.IsDefined() ||
-	       chunk->CheckFormat(mp->audio_format));
+	assert(size > 0 || !audio_format.IsDefined());
+	assert(!audio_format.IsDefined() ||
+	       chunk->CheckFormat(audio_format));
 
 #ifndef NDEBUG
-	if (!mp->audio_format.IsDefined() && chunk->length > 0)
-		mp->audio_format = chunk->audio_format;
+	if (!audio_format.IsDefined() && chunk->length > 0)
+		audio_format = chunk->audio_format;
 #endif
 
-	chunk->next = NULL;
-	*mp->tail_r = chunk;
-	mp->tail_r = &chunk->next;
-
-	++mp->size;
-}
+	chunk->next = nullptr;
+	*tail_r = chunk;
+	tail_r = &chunk->next;
 
-unsigned
-music_pipe_size(const struct music_pipe *mp)
-{
-	const ScopeLock protect(mp->mutex);
-	return mp->size;
+	++size;
 }

src/MusicPipe.hxx

@@ -20,12 +20,15 @@
 #ifndef MPD_PIPE_H
 #define MPD_PIPE_H
 
+#include "thread/Mutex.hxx"
 #include "gcc.h"
 
 #ifndef NDEBUG
-struct AudioFormat;
+#include "AudioFormat.hxx"
 #endif
 
+#include <assert.h>
+
 struct music_chunk;
 struct music_buffer;
 
@@ -33,80 +36,98 @@ struct music_buffer;
  * A queue of #music_chunk objects.  One party appends chunks at the
  * tail, and the other consumes them from the head.
  */
-struct music_pipe;
+class MusicPipe {
+	/** the first chunk */
+	music_chunk *head;
 
-/**
- * Creates a new #music_pipe object.  It is empty.
- */
-gcc_malloc
-struct music_pipe *
-music_pipe_new(void);
+	/** a pointer to the tail of the chunk */
+	music_chunk **tail_r;
 
-/**
- * Frees the object.  It must be empty now.
- */
-void
-music_pipe_free(struct music_pipe *mp);
+	/** the current number of chunks */
+	unsigned size;
 
-#ifndef NDEBUG
-
-/**
- * Checks if the audio format if the chunk is equal to the specified
- * audio_format.
- */
-bool
-music_pipe_check_format(const struct music_pipe *pipe,
-			AudioFormat audio_format);
-
-/**
- * Checks if the specified chunk is enqueued in the music pipe.
- */
-bool
-music_pipe_contains(const struct music_pipe *mp,
-		    const struct music_chunk *chunk);
+	/** a mutex which protects #head and #tail_r */
+	mutable Mutex mutex;
 
+#ifndef NDEBUG
+	AudioFormat audio_format;
 #endif
 
-/**
- * Returns the first #music_chunk from the pipe.  Returns NULL if the
- * pipe is empty.
- */
-gcc_pure
-const struct music_chunk *
-music_pipe_peek(const struct music_pipe *mp);
-
-/**
- * Removes the first chunk from the head, and returns it.
- */
-struct music_chunk *
-music_pipe_shift(struct music_pipe *mp);
+public:
+	/**
+	 * Creates a new #MusicPipe object.  It is empty.
+	 */
+	MusicPipe()
+		:head(nullptr), tail_r(&head), size(0) {
+#ifndef NDEBUG
+		audio_format.Clear();
+#endif
+	}
 
-/**
- * Clears the whole pipe and returns the chunks to the buffer.
- *
- * @param buffer the buffer object to return the chunks to
- */
-void
-music_pipe_clear(struct music_pipe *mp, struct music_buffer *buffer);
+	/**
+	 * Frees the object.  It must be empty now.
+	 */
+	~MusicPipe() {
+		assert(head == nullptr);
+		assert(tail_r == &head);
+	}
 
-/**
- * Pushes a chunk to the tail of the pipe.
- */
-void
-music_pipe_push(struct music_pipe *mp, struct music_chunk *chunk);
+#ifndef NDEBUG
+	/**
+	 * Checks if the audio format if the chunk is equal to the specified
+	 * audio_format.
+	 */
+	gcc_pure
+	bool CheckFormat(AudioFormat other) const {
+		return !audio_format.IsDefined() ||
+			audio_format == other;
+	}
+
+	/**
+	 * Checks if the specified chunk is enqueued in the music pipe.
+	 */
+	gcc_pure
+	bool Contains(const music_chunk *chunk) const;
+#endif
 
-/**
- * Returns the number of chunks currently in this pipe.
- */
-gcc_pure
-unsigned
-music_pipe_size(const struct music_pipe *mp);
-
-gcc_pure
-static inline bool
-music_pipe_empty(const struct music_pipe *mp)
-{
-	return music_pipe_size(mp) == 0;
-}
+	/**
+	 * Returns the first #music_chunk from the pipe.  Returns
+	 * nullptr if the pipe is empty.
+	 */
+	gcc_pure
+	const music_chunk *Peek() const {
+		return head;
+	}
+
+	/**
+	 * Removes the first chunk from the head, and returns it.
+	 */
+	music_chunk *Shift();
+
+	/**
+	 * Clears the whole pipe and returns the chunks to the buffer.
+	 *
+	 * @param buffer the buffer object to return the chunks to
+	 */
+	void Clear(music_buffer *buffer);
+
+	/**
+	 * Pushes a chunk to the tail of the pipe.
+	 */
+	void Push(music_chunk *chunk);
+
+	/**
+	 * Returns the number of chunks currently in this pipe.
+	 */
+	gcc_pure
+	unsigned GetSize() const {
+		return size;
+	}
+
+	gcc_pure
+	bool IsEmpty() const {
+		return GetSize() == 0;
+	}
+};
 
 #endif

src/OutputAll.cxx

@@ -50,10 +50,10 @@ static unsigned int num_audio_outputs;
 static struct music_buffer *g_music_buffer;
 
 /**
- * The #music_pipe object which feeds all audio outputs.  It is filled
+ * The #MusicPipe object which feeds all audio outputs.  It is filled
  * by audio_output_all_play().
  */
-static struct music_pipe *g_mp;
+static MusicPipe *g_mp;
 
 /**
  * The "elapsed_time" stamp of the most recently finished chunk.
@@ -262,7 +262,7 @@ audio_output_all_update(void)
 
 	for (i = 0; i < num_audio_outputs; ++i)
 		ret = audio_output_update(audio_outputs[i],
-					  input_audio_format, g_mp) || ret;
+					  input_audio_format, *g_mp) || ret;
 
 	return ret;
 }
@@ -292,7 +292,7 @@ audio_output_all_play(struct music_chunk *chunk, Error &error)
 		return false;
 	}
 
-	music_pipe_push(g_mp, chunk);
+	g_mp->Push(chunk);
 
 	for (i = 0; i < num_audio_outputs; ++i)
 		audio_output_play(audio_outputs[i]);
@@ -316,15 +316,14 @@ audio_output_all_open(const AudioFormat audio_format,
 
 	/* the audio format must be the same as existing chunks in the
 	   pipe */
-	assert(g_mp == NULL || music_pipe_check_format(g_mp, audio_format));
+	assert(g_mp == NULL || g_mp->CheckFormat(audio_format));
 
 	if (g_mp == NULL)
-		g_mp = music_pipe_new();
+		g_mp = new MusicPipe();
 	else
 		/* if the pipe hasn't been cleared, the the audio
 		   format must not have changed */
-		assert(music_pipe_empty(g_mp) ||
-		       audio_format == input_audio_format);
+		assert(g_mp->IsEmpty() || audio_format == input_audio_format);
 
 	input_audio_format = audio_format;
 
@@ -366,7 +365,7 @@ chunk_is_consumed_in(const struct audio_output *ao,
 	if (ao->chunk == NULL)
 		return false;
 
-	assert(chunk == ao->chunk || music_pipe_contains(g_mp, ao->chunk));
+	assert(chunk == ao->chunk || g_mp->Contains(ao->chunk));
 
 	if (chunk != ao->chunk) {
 		assert(chunk->next != NULL);
@@ -401,7 +400,7 @@ static void
 clear_tail_chunk(gcc_unused const struct music_chunk *chunk, bool *locked)
 {
 	assert(chunk->next == NULL);
-	assert(music_pipe_contains(g_mp, chunk));
+	assert(g_mp->Contains(chunk));
 
 	for (unsigned i = 0; i < num_audio_outputs; ++i) {
 		struct audio_output *ao = audio_outputs[i];
@@ -433,13 +432,13 @@ audio_output_all_check(void)
 	assert(g_music_buffer != NULL);
 	assert(g_mp != NULL);
 
-	while ((chunk = music_pipe_peek(g_mp)) != NULL) {
-		assert(!music_pipe_empty(g_mp));
+	while ((chunk = g_mp->Peek()) != nullptr) {
+		assert(!g_mp->IsEmpty());
 
 		if (!chunk_is_consumed(chunk))
 			/* at least one output is not finished playing
 			   this chunk */
-			return music_pipe_size(g_mp);
+			return g_mp->GetSize();
 
 		if (chunk->length > 0 && chunk->times >= 0.0)
 			/* only update elapsed_time if the chunk
@@ -453,7 +452,7 @@ audio_output_all_check(void)
 			clear_tail_chunk(chunk, locked);
 
 		/* remove the chunk from the pipe */
-		shifted = music_pipe_shift(g_mp);
+		shifted = g_mp->Shift();
 		assert(shifted == chunk);
 
 		if (is_tail)
@@ -523,7 +522,7 @@ audio_output_all_cancel(void)
 	/* clear the music pipe and return all chunks to the buffer */
 
 	if (g_mp != NULL)
-		music_pipe_clear(g_mp, g_music_buffer);
+		g_mp->Clear(g_music_buffer);
 
 	/* the audio outputs are now waiting for a signal, to
 	   synchronize the cleared music pipe */
@@ -546,8 +545,8 @@ audio_output_all_close(void)
 	if (g_mp != NULL) {
 		assert(g_music_buffer != NULL);
 
-		music_pipe_clear(g_mp, g_music_buffer);
-		music_pipe_free(g_mp);
+		g_mp->Clear(g_music_buffer);
+		delete g_mp;
 		g_mp = NULL;
 	}
 
@@ -569,8 +568,8 @@ audio_output_all_release(void)
 	if (g_mp != NULL) {
 		assert(g_music_buffer != NULL);
 
-		music_pipe_clear(g_mp, g_music_buffer);
-		music_pipe_free(g_mp);
+		g_mp->Clear(g_music_buffer);
+		delete g_mp;
 		g_mp = NULL;
 	}
 

src/OutputAll.hxx

@@ -104,7 +104,7 @@ audio_output_all_set_replay_gain_mode(enum replay_gain_mode mode);
 
 /**
  * Enqueue a #music_chunk object for playing, i.e. pushes it to a
- * #music_pipe.
+ * #MusicPipe.
  *
  * @param chunk the #music_chunk object to be played
  * @return true on success, false if no audio output was able to play
@@ -117,13 +117,13 @@ audio_output_all_play(struct music_chunk *chunk, Error &error);
  * Checks if the output devices have drained their music pipe, and
  * returns the consumed music chunks to the #music_buffer.
  *
- * @return the number of chunks to play left in the #music_pipe
+ * @return the number of chunks to play left in the #MusicPipe
  */
 unsigned
 audio_output_all_check(void);
 
 /**
- * Checks if the size of the #music_pipe is below the #threshold.  If
+ * Checks if the size of the #MusicPipe is below the #threshold.  If
  * not, it attempts to synchronize with all output threads, and waits
  * until another #music_chunk is finished.
  *

src/OutputControl.cxx

@@ -141,14 +141,13 @@ audio_output_disable(struct audio_output *ao)
 static bool
 audio_output_open(struct audio_output *ao,
 		  const AudioFormat audio_format,
-		  const struct music_pipe *mp)
+		  const MusicPipe &mp)
 {
 	bool open;
 
 	assert(ao != NULL);
 	assert(ao->allow_play);
 	assert(audio_format.IsValid());
-	assert(mp != NULL);
 
 	if (ao->fail_timer != NULL) {
 		g_timer_destroy(ao->fail_timer);
@@ -156,12 +155,12 @@ audio_output_open(struct audio_output *ao,
 	}
 
 	if (ao->open && audio_format == ao->in_audio_format) {
-		assert(ao->pipe == mp ||
+		assert(ao->pipe == &mp ||
 		       (ao->always_on && ao->pause));
 
 		if (ao->pause) {
 			ao->chunk = NULL;
-			ao->pipe = mp;
+			ao->pipe = ∓
 
 			/* unpause with the CANCEL command; this is a
 			   hack, but suits well for forcing the thread
@@ -179,7 +178,7 @@ audio_output_open(struct audio_output *ao,
 	ao->in_audio_format = audio_format;
 	ao->chunk = NULL;
 
-	ao->pipe = mp;
+	ao->pipe = ∓
 
 	if (ao->thread == NULL)
 		audio_output_thread_start(ao);
@@ -223,10 +222,8 @@ audio_output_close_locked(struct audio_output *ao)
 bool
 audio_output_update(struct audio_output *ao,
 		    const AudioFormat audio_format,
-		    const struct music_pipe *mp)
+		    const MusicPipe &mp)
 {
-	assert(mp != NULL);
-
 	const ScopeLock protect(ao->mutex);
 
 	if (ao->enabled && ao->really_enabled) {

src/OutputControl.hxx

@@ -27,7 +27,7 @@
 struct audio_output;
 struct AudioFormat;
 struct config_param;
-struct music_pipe;
+class MusicPipe;
 struct player_control;
 
 void
@@ -54,7 +54,7 @@ audio_output_disable(struct audio_output *ao);
 bool
 audio_output_update(struct audio_output *ao,
 		    AudioFormat audio_format,
-		    const struct music_pipe *mp);
+		    const MusicPipe &mp);
 
 void
 audio_output_play(struct audio_output *ao);

src/OutputInternal.hxx

@@ -31,6 +31,7 @@
 
 class Error;
 class Filter;
+class MusicPipe;
 struct config_param;
 
 enum audio_output_command {
@@ -209,7 +210,7 @@ struct audio_output {
 	/**
 	 * The music pipe which provides music chunks to be played.
 	 */
-	const struct music_pipe *pipe;
+	const MusicPipe *pipe;
 
 	/**
 	 * This mutex protects #open, #fail_timer, #chunk and

src/OutputThread.cxx

@@ -263,7 +263,7 @@ ao_reopen(struct audio_output *ao)
 {
 	if (!ao->config_audio_format.IsFullyDefined()) {
 		if (ao->open) {
-			const struct music_pipe *mp = ao->pipe;
+			const MusicPipe *mp = ao->pipe;
 			ao_close(ao, true);
 			ao->pipe = mp;
 		}
@@ -484,7 +484,7 @@ ao_next_chunk(struct audio_output *ao)
 		/* continue the previous play() call */
 		? ao->chunk->next
 		/* get the first chunk from the pipe */
-		: music_pipe_peek(ao->pipe);
+		: ao->pipe->Peek();
 }
 
 /**
@@ -621,7 +621,7 @@ static gpointer audio_output_task(gpointer arg)
 		case AO_COMMAND_DRAIN:
 			if (ao->open) {
 				assert(ao->chunk == NULL);
-				assert(music_pipe_peek(ao->pipe) == NULL);
+				assert(ao->pipe->Peek() == nullptr);
 
 				ao->mutex.unlock();
 				ao_plugin_drain(ao);

src/PlayerThread.cxx

@@ -54,7 +54,7 @@ struct player {
 
 	struct decoder_control *dc;
 
-	struct music_pipe *pipe;
+	MusicPipe *pipe;
 
 	/**
 	 * are we waiting for buffered_before_play?
@@ -166,7 +166,7 @@ player_command_finished(struct player_control *pc)
  * Player lock is not held.
  */
 static void
-player_dc_start(struct player *player, struct music_pipe *pipe)
+player_dc_start(struct player *player, MusicPipe &pipe)
 {
 	struct player_control *pc = player->pc;
 	struct decoder_control *dc = player->dc;
@@ -224,10 +224,10 @@ player_dc_stop(struct player *player)
 	if (dc->pipe != NULL) {
 		/* clear and free the decoder pipe */
 
-		music_pipe_clear(dc->pipe, player_buffer);
+		dc->pipe->Clear(player_buffer);
 
 		if (dc->pipe != player->pipe)
-			music_pipe_free(dc->pipe);
+			delete dc->pipe;
 
 		dc->pipe = NULL;
 	}
@@ -493,10 +493,10 @@ static bool player_seek_decoder(struct player *player)
 
 		/* clear music chunks which might still reside in the
 		   pipe */
-		music_pipe_clear(player->pipe, player_buffer);
+		player->pipe->Clear(player_buffer);
 
 		/* re-start the decoder */
-		player_dc_start(player, player->pipe);
+		player_dc_start(player, *player->pipe);
 		if (!player_wait_for_decoder(player)) {
 			/* decoder failure */
 			player_command_finished(pc);
@@ -506,8 +506,8 @@ static bool player_seek_decoder(struct player *player)
 		if (!player_dc_at_current_song(player)) {
 			/* the decoder is already decoding the "next" song,
 			   but it is the same song file; exchange the pipe */
-			music_pipe_clear(player->pipe, player_buffer);
-			music_pipe_free(player->pipe);
+			player->pipe->Clear(player_buffer);
+			delete player->pipe;
 			player->pipe = dc->pipe;
 		}
 
@@ -734,11 +734,10 @@ play_next_chunk(struct player *player)
 	struct music_chunk *chunk = NULL;
 	if (player->xfade == XFADE_ENABLED &&
 	    player_dc_at_next_song(player) &&
-	    (cross_fade_position = music_pipe_size(player->pipe))
+	    (cross_fade_position = player->pipe->GetSize())
 	    <= player->cross_fade_chunks) {
 		/* perform cross fade */
-		struct music_chunk *other_chunk =
-			music_pipe_shift(dc->pipe);
+		music_chunk *other_chunk = dc->pipe->Shift();
 
 		if (!player->cross_fading) {
 			/* beginning of the cross fade - adjust
@@ -750,7 +749,7 @@ play_next_chunk(struct player *player)
 		}
 
 		if (other_chunk != NULL) {
-			chunk = music_pipe_shift(player->pipe);
+			chunk = player->pipe->Shift();
 			assert(chunk != NULL);
 			assert(chunk->other == NULL);
 
@@ -806,7 +805,7 @@ play_next_chunk(struct player *player)
 	}
 
 	if (chunk == NULL)
-		chunk = music_pipe_shift(player->pipe);
+		chunk = player->pipe->Shift();
 
 	assert(chunk != NULL);
 
@@ -848,8 +847,8 @@ play_next_chunk(struct player *player)
 	   larger block at a time */
 	dc->Lock();
 	if (!dc->IsIdle() &&
-	    music_pipe_size(dc->pipe) <= (pc->buffered_before_play +
-					 music_buffer_size(player_buffer) * 3) / 4)
+	    dc->pipe->GetSize() <= (pc->buffered_before_play +
+				    music_buffer_size(player_buffer) * 3) / 4)
 		dc->Signal();
 	dc->Unlock();
 
@@ -874,7 +873,7 @@ player_song_border(struct player *player)
 	g_message("played \"%s\"", uri);
 	g_free(uri);
 
-	music_pipe_free(player->pipe);
+	delete player->pipe;
 	player->pipe = player->dc->pipe;
 
 	audio_output_all_song_border();
@@ -910,15 +909,15 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 
 	pc->Unlock();
 
-	player.pipe = music_pipe_new();
+	player.pipe = new MusicPipe();
 
-	player_dc_start(&player, player.pipe);
+	player_dc_start(&player, *player.pipe);
 	if (!player_wait_for_decoder(&player)) {
 		assert(player.song == NULL);
 
 		player_dc_stop(&player);
 		player_command_finished(pc);
-		music_pipe_free(player.pipe);
+		delete player.pipe;
 		GlobalEvents::Emit(GlobalEvents::PLAYLIST);
 		pc->Lock();
 		return;
@@ -949,7 +948,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 			   until the buffer is large enough, to
 			   prevent stuttering on slow machines */
 
-			if (music_pipe_size(player.pipe) < pc->buffered_before_play &&
+			if (player.pipe->GetSize() < pc->buffered_before_play &&
 			    !dc->LockIsIdle()) {
 				/* not enough decoded buffer space yet */
 
@@ -996,7 +995,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 
 			assert(dc->pipe == NULL || dc->pipe == player.pipe);
 
-			player_dc_start(&player, music_pipe_new());
+			player_dc_start(&player, *new MusicPipe());
 		}
 
 		if (/* no cross-fading if MPD is going to pause at the
@@ -1035,7 +1034,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 			if (pc->command == PLAYER_COMMAND_NONE)
 				pc->Wait();
 			continue;
-		} else if (!music_pipe_empty(player.pipe)) {
+		} else if (!player.pipe->IsEmpty()) {
 			/* at least one music chunk is ready - send it
 			   to the audio output */
 
@@ -1056,7 +1055,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 			/* check the size of the pipe again, because
 			   the decoder thread may have added something
 			   since we last checked */
-			if (music_pipe_empty(player.pipe)) {
+			if (player.pipe->IsEmpty()) {
 				/* wait for the hardware to finish
 				   playback */
 				audio_output_all_drain();
@@ -1075,8 +1074,8 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 
 	player_dc_stop(&player);
 
-	music_pipe_clear(player.pipe, player_buffer);
-	music_pipe_free(player.pipe);
+	player.pipe->Clear(player_buffer);
+	delete player.pipe;
 
 	delete player.cross_fade_tag;
 

src/PlayerThread.hxx

@@ -31,7 +31,7 @@
  *
  * The player thread itself does not do any I/O.  It synchronizes with
  * other threads via #GMutex and #GCond objects, and passes
- * #music_chunk instances around in #music_pipe objects.
+ * #music_chunk instances around in #MusicPipe objects.
  */
 
 #ifndef MPD_PLAYER_THREAD_HXX