MusicBuffer: expose the C++ API

src/DecoderAPI.cxx

@@ -178,11 +178,11 @@ decoder_command_finished(struct decoder *decoder)
 		/* delete frames from the old song position */
 
 		if (decoder->chunk != NULL) {
-			music_buffer_return(dc->buffer, decoder->chunk);
+			dc->buffer->Return(decoder->chunk);
 			decoder->chunk = NULL;
 		}
 
-		dc->pipe->Clear(dc->buffer);
+		dc->pipe->Clear(*dc->buffer);
 
 		decoder->timestamp = dc->seek_where;
 	}

src/DecoderControl.cxx

@@ -105,10 +105,9 @@ decoder_control::IsCurrentSong(const Song *_song) const
 void
 decoder_control::Start(Song *_song,
 		       unsigned _start_ms, unsigned _end_ms,
-		       music_buffer *_buffer, MusicPipe &_pipe)
+		       MusicBuffer &_buffer, MusicPipe &_pipe)
 {
 	assert(_song != NULL);
-	assert(_buffer != NULL);
 	assert(_pipe.IsEmpty());
 
 	if (song != nullptr)
@@ -117,7 +116,7 @@ decoder_control::Start(Song *_song,
 	song = _song;
 	start_ms = _start_ms;
 	end_ms = _end_ms;
-	buffer = _buffer;
+	buffer = &_buffer;
 	pipe = &_pipe;
 
 	dc_command(this, DECODE_COMMAND_START);

src/DecoderControl.hxx

@@ -31,6 +31,7 @@
 #include <assert.h>
 
 struct Song;
+class MusicBuffer;
 class MusicPipe;
 
 enum decoder_state {
@@ -122,7 +123,7 @@ struct decoder_control {
 	float total_time;
 
 	/** the #music_chunk allocator */
-	struct music_buffer *buffer;
+	MusicBuffer *buffer;
 
 	/**
 	 * The destination pipe for decoded chunks.  The caller thread
@@ -288,7 +289,7 @@ struct decoder_control {
 	 * the caller)
 	 */
 	void Start(Song *song, unsigned start_ms, unsigned end_ms,
-		   music_buffer *buffer, MusicPipe &pipe);
+		   MusicBuffer &buffer, MusicPipe &pipe);
 
 	void Stop();
 

src/DecoderInternal.cxx

@@ -70,7 +70,7 @@ decoder_get_chunk(struct decoder *decoder)
 		return decoder->chunk;
 
 	do {
-		decoder->chunk = music_buffer_allocate(dc->buffer);
+		decoder->chunk = dc->buffer->Allocate();
 		if (decoder->chunk != NULL) {
 			decoder->chunk->replay_gain_serial =
 				decoder->replay_gain_serial;
@@ -98,7 +98,7 @@ decoder_flush_chunk(struct decoder *decoder)
 	assert(decoder->chunk != NULL);
 
 	if (decoder->chunk->IsEmpty())
-		music_buffer_return(dc->buffer, decoder->chunk);
+		dc->buffer->Return(decoder->chunk);
 	else
 		dc->pipe->Push(decoder->chunk);
 

src/MusicBuffer.cxx

@@ -20,60 +20,34 @@
 #include "config.h"
 #include "MusicBuffer.hxx"
 #include "MusicChunk.hxx"
-#include "thread/Mutex.hxx"
-#include "util/SliceBuffer.hxx"
 #include "system/FatalError.hxx"
 
 #include <assert.h>
 
-struct music_buffer : public SliceBuffer<music_chunk>  {
+MusicBuffer::MusicBuffer(unsigned num_chunks)
-	/** a mutex which protects #available */
+	:buffer(num_chunks) {
-	Mutex mutex;
+	if (buffer.IsOOM())
-
-	music_buffer(unsigned num_chunks)
-		:SliceBuffer(num_chunks) {
-		if (IsOOM())
 		FatalError("Failed to allocate buffer");
 }
-};
 
-struct music_buffer *
+music_chunk *
-music_buffer_new(unsigned num_chunks)
+MusicBuffer::Allocate()
 {
-	return new music_buffer(num_chunks);
+	const ScopeLock protect(mutex);
+	return buffer.Allocate();
 }
 
 void
-music_buffer_free(struct music_buffer *buffer)
+MusicBuffer::Return(music_chunk *chunk)
 {
-	delete buffer;
+	assert(chunk != nullptr);
-}
 
-unsigned
+	const ScopeLock protect(mutex);
-music_buffer_size(const struct music_buffer *buffer)
-{
-	return buffer->GetCapacity();
-}
-
-struct music_chunk *
-music_buffer_allocate(struct music_buffer *buffer)
-{
-	const ScopeLock protect(buffer->mutex);
-	return buffer->Allocate();
-}
-
-void
-music_buffer_return(struct music_buffer *buffer, struct music_chunk *chunk)
-{
-	assert(buffer != NULL);
-	assert(chunk != NULL);
-
-	const ScopeLock protect(buffer->mutex);
 
 	if (chunk->other != nullptr) {
 		assert(chunk->other->other == nullptr);
-		buffer->Free(chunk->other);
+		buffer.Free(chunk->other);
 	}
 
-	buffer->Free(chunk);
+	buffer.Free(chunk);
 }

src/MusicBuffer.hxx

@@ -20,48 +20,53 @@
 #ifndef MPD_MUSIC_BUFFER_HXX
 #define MPD_MUSIC_BUFFER_HXX
 
+#include "util/SliceBuffer.hxx"
+#include "thread/Mutex.hxx"
+
+struct music_chunk;
+
 /**
  * An allocator for #music_chunk objects.
  */
-struct music_buffer;
+class MusicBuffer {
+	/** a mutex which protects #buffer */
+	Mutex mutex;
 
+	SliceBuffer<music_chunk> buffer;
+
+public:
 	/**
- * Creates a new #music_buffer object.
+	 * Creates a new #MusicBuffer object.
 	 *
- * @param num_chunks the number of #music_chunk reserved in this
+	 * @param num_chunks the number of #music_chunk reserved in
- * buffer
+	 * this buffer
 	 */
-struct music_buffer *
+	MusicBuffer(unsigned num_chunks);
-music_buffer_new(unsigned num_chunks);
-
-/**
- * Frees the #music_buffer object
- */
-void
-music_buffer_free(struct music_buffer *buffer);
 
 	/**
 	 * Returns the total number of reserved chunks in this buffer.  This
 	 * is the same value which was passed to the constructor
 	 * music_buffer_new().
 	 */
-unsigned
+	gcc_pure
-music_buffer_size(const struct music_buffer *buffer);
+	unsigned GetSize() const {
+		return buffer.GetCapacity();
+	}
 
 	/**
 	 * Allocates a chunk from the buffer.  When it is not used anymore,
- * call music_buffer_return().
+	 * call Return().
 	 *
- * @return an empty chunk or NULL if there are no chunks available
+	 * @return an empty chunk or nullptr if there are no chunks
+	 * available
 	 */
-struct music_chunk *
+	music_chunk *Allocate();
-music_buffer_allocate(struct music_buffer *buffer);
 
 	/**
 	 * Returns a chunk to the buffer.  It can be reused by
- * music_buffer_allocate() then.
+	 * Allocate() then.
 	 */
-void
+	void Return(music_chunk *chunk);
-music_buffer_return(struct music_buffer *buffer, struct music_chunk *chunk);
+};
 
 #endif

src/MusicPipe.cxx

@@ -73,12 +73,12 @@ MusicPipe::Shift()
 }
 
 void
-MusicPipe::Clear(music_buffer *buffer)
+MusicPipe::Clear(MusicBuffer &buffer)
 {
 	music_chunk *chunk;
 
 	while ((chunk = Shift()) != nullptr)
-		music_buffer_return(buffer, chunk);
+		buffer.Return(chunk);
 }
 
 void

src/MusicPipe.hxx

@@ -30,7 +30,7 @@
 #include <assert.h>
 
 struct music_chunk;
-struct music_buffer;
+class MusicBuffer;
 
 /**
  * A queue of #music_chunk objects.  One party appends chunks at the
@@ -109,7 +109,7 @@ public:
 	 *
 	 * @param buffer the buffer object to return the chunks to
 	 */
-	void Clear(music_buffer *buffer);
+	void Clear(MusicBuffer &buffer);
 
 	/**
 	 * Pushes a chunk to the tail of the pipe.

src/OutputAll.cxx

@@ -45,9 +45,9 @@ static struct audio_output **audio_outputs;
 static unsigned int num_audio_outputs;
 
 /**
- * The #music_buffer object where consumed chunks are returned.
+ * The #MusicBuffer object where consumed chunks are returned.
  */
-static struct music_buffer *g_music_buffer;
+static MusicBuffer *g_music_buffer;
 
 /**
  * The #MusicPipe object which feeds all audio outputs.  It is filled
@@ -302,17 +302,16 @@ audio_output_all_play(struct music_chunk *chunk, Error &error)
 
 bool
 audio_output_all_open(const AudioFormat audio_format,
-		      struct music_buffer *buffer,
+		      MusicBuffer &buffer,
 		      Error &error)
 {
 	bool ret = false, enabled = false;
 	unsigned int i;
 
-	assert(buffer != NULL);
+	assert(g_music_buffer == NULL || g_music_buffer == &buffer);
-	assert(g_music_buffer == NULL || g_music_buffer == buffer);
 	assert((g_mp == NULL) == (g_music_buffer == NULL));
 
-	g_music_buffer = buffer;
+	g_music_buffer = &buffer;
 
 	/* the audio format must be the same as existing chunks in the
 	   pipe */
@@ -463,7 +462,7 @@ audio_output_all_check(void)
 					audio_outputs[i]->mutex.unlock();
 
 		/* return the chunk to the buffer */
-		music_buffer_return(g_music_buffer, shifted);
+		g_music_buffer->Return(shifted);
 	}
 
 	return 0;
@@ -522,7 +521,7 @@ audio_output_all_cancel(void)
 	/* clear the music pipe and return all chunks to the buffer */
 
 	if (g_mp != NULL)
-		g_mp->Clear(g_music_buffer);
+		g_mp->Clear(*g_music_buffer);
 
 	/* the audio outputs are now waiting for a signal, to
 	   synchronize the cleared music pipe */
@@ -545,7 +544,7 @@ audio_output_all_close(void)
 	if (g_mp != NULL) {
 		assert(g_music_buffer != NULL);
 
-		g_mp->Clear(g_music_buffer);
+		g_mp->Clear(*g_music_buffer);
 		delete g_mp;
 		g_mp = NULL;
 	}
@@ -568,7 +567,7 @@ audio_output_all_release(void)
 	if (g_mp != NULL) {
 		assert(g_music_buffer != NULL);
 
-		g_mp->Clear(g_music_buffer);
+		g_mp->Clear(*g_music_buffer);
 		delete g_mp;
 		g_mp = NULL;
 	}

src/OutputAll.hxx

@@ -29,7 +29,7 @@
 #include "replay_gain_info.h"
 
 struct AudioFormat;
-struct music_buffer;
+class MusicBuffer;
 struct music_chunk;
 struct player_control;
 class Error;
@@ -83,7 +83,7 @@ audio_output_all_enable_disable(void);
  */
 bool
 audio_output_all_open(AudioFormat audio_format,
-		      struct music_buffer *buffer,
+		      MusicBuffer &buffer,
 		      Error &error);
 
 /**

src/PlayerThread.cxx

@@ -141,7 +141,7 @@ struct player {
 		 elapsed_time(0.0) {}
 };
 
-static struct music_buffer *player_buffer;
+static MusicBuffer *player_buffer;
 
 static void
 player_command_finished_locked(struct player_control *pc)
@@ -180,7 +180,7 @@ player_dc_start(struct player *player, MusicPipe &pipe)
 
 	dc->Start(pc->next_song->DupDetached(),
 		  start_ms, pc->next_song->end_ms,
-		  player_buffer, pipe);
+		  *player_buffer, pipe);
 }
 
 /**
@@ -224,7 +224,7 @@ player_dc_stop(struct player *player)
 	if (dc->pipe != NULL) {
 		/* clear and free the decoder pipe */
 
-		dc->pipe->Clear(player_buffer);
+		dc->pipe->Clear(*player_buffer);
 
 		if (dc->pipe != player->pipe)
 			delete dc->pipe;
@@ -328,7 +328,7 @@ player_open_output(struct player *player)
 	       pc->state == PLAYER_STATE_PAUSE);
 
 	Error error;
-	if (audio_output_all_open(player->play_audio_format, player_buffer,
+	if (audio_output_all_open(player->play_audio_format, *player_buffer,
 				  error)) {
 		player->output_open = true;
 		player->paused = false;
@@ -441,7 +441,7 @@ player_send_silence(struct player *player)
 	assert(player->output_open);
 	assert(player->play_audio_format.IsDefined());
 
-	struct music_chunk *chunk = music_buffer_allocate(player_buffer);
+	struct music_chunk *chunk = player_buffer->Allocate();
 	if (chunk == NULL) {
 		g_warning("Failed to allocate silence buffer");
 		return false;
@@ -463,7 +463,7 @@ player_send_silence(struct player *player)
 	Error error;
 	if (!audio_output_all_play(chunk, error)) {
 		g_warning("%s", error.GetMessage());
-		music_buffer_return(player_buffer, chunk);
+		player_buffer->Return(chunk);
 		return false;
 	}
 
@@ -493,7 +493,7 @@ static bool player_seek_decoder(struct player *player)
 
 		/* clear music chunks which might still reside in the
 		   pipe */
-		player->pipe->Clear(player_buffer);
+		player->pipe->Clear(*player_buffer);
 
 		/* re-start the decoder */
 		player_dc_start(player, *player->pipe);
@@ -506,7 +506,7 @@ 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 */
-			player->pipe->Clear(player_buffer);
+			player->pipe->Clear(*player_buffer);
 			delete player->pipe;
 			player->pipe = dc->pipe;
 		}
@@ -695,7 +695,7 @@ play_chunk(struct player_control *pc,
 		update_song_tag(song, *chunk->tag);
 
 	if (chunk->length == 0) {
-		music_buffer_return(player_buffer, chunk);
+		player_buffer->Return(chunk);
 		return true;
 	}
 
@@ -776,8 +776,7 @@ play_next_chunk(struct player *player)
 				   beginning of the new song, we can
 				   easily recover by throwing it away
 				   now */
-				music_buffer_return(player_buffer,
+				player_buffer->Return(other_chunk);
-						    other_chunk);
 				other_chunk = NULL;
 			}
 
@@ -824,7 +823,7 @@ play_next_chunk(struct player *player)
 			player->play_audio_format, error)) {
 		g_warning("%s", error.GetMessage());
 
-		music_buffer_return(player_buffer, chunk);
+		player_buffer->Return(chunk);
 
 		pc->Lock();
 
@@ -848,7 +847,7 @@ play_next_chunk(struct player *player)
 	dc->Lock();
 	if (!dc->IsIdle() &&
 	    dc->pipe->GetSize() <= (pc->buffered_before_play +
-				    music_buffer_size(player_buffer) * 3) / 4)
+				    player_buffer->GetSize() * 3) / 4)
 		dc->Signal();
 	dc->Unlock();
 
@@ -1017,7 +1016,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 						dc->mixramp_prev_end,
 						dc->out_audio_format,
 						player.play_audio_format,
-						music_buffer_size(player_buffer) -
+						player_buffer->GetSize() -
 						pc->buffered_before_play);
 			if (player.cross_fade_chunks > 0) {
 				player.xfade = XFADE_ENABLED;
@@ -1074,7 +1073,7 @@ static void do_play(struct player_control *pc, struct decoder_control *dc)
 
 	player_dc_stop(&player);
 
-	player.pipe->Clear(player_buffer);
+	player.pipe->Clear(*player_buffer);
 	delete player.pipe;
 
 	delete player.cross_fade_tag;
@@ -1107,7 +1106,7 @@ player_task(gpointer arg)
 	struct decoder_control *dc = new decoder_control();
 	decoder_thread_start(dc);
 
-	player_buffer = music_buffer_new(pc->buffer_chunks);
+	player_buffer = new MusicBuffer(pc->buffer_chunks);
 
 	pc->Lock();
 
@@ -1148,8 +1147,8 @@ player_task(gpointer arg)
 			/* in the DEBUG build, check for leaked
 			   music_chunk objects by freeing the
 			   music_buffer */
-			music_buffer_free(player_buffer);
+			delete player_buffer;
-			player_buffer = music_buffer_new(pc->buffer_chunks);
+			player_buffer = new MusicBuffer(pc->buffer_chunks);
 #endif
 
 			break;
@@ -1167,7 +1166,7 @@ player_task(gpointer arg)
 			dc->Quit();
 			delete dc;
 			audio_output_all_close();
-			music_buffer_free(player_buffer);
+			delete player_buffer;
 
 			player_command_finished(pc);
 			return NULL;