audio: removed audio_buffer.buffer

audio.c maintained one of MPD's many layers of audio buffers.  It was
without any benefit, since playAudio() can simply send the source
buffer directly to the audio output plugin.

src/audio.c

@@ -48,9 +48,6 @@ static uint8_t audioOpened;
 
 static struct {
 	struct audio_format format;
-
-	size_t size, position;
-	char *buffer;
 } audio_buffer;
 
 static unsigned int audio_output_count(void)
@@ -262,21 +259,17 @@ static void syncAudioDeviceStates(void)
 	}
 }
 
-static int flushAudioBuffer(void)
+int playAudio(const char *buffer, size_t length)
 {
 	int ret = -1, err;
 	unsigned int i;
 
-	if (audio_buffer.position == 0)
-		return 0;
-
 	syncAudioDeviceStates();
 
 	for (i = 0; i < audioOutputArraySize; ++i)
 		if (audio_output_is_open(&audioOutputArray[i]))
 			audio_output_play(&audioOutputArray[i],
-					  audio_buffer.buffer,
+					  buffer, length);
-					  audio_buffer.position);
 
 	while (1) {
 		int finished = 1;
@@ -308,35 +301,9 @@ static int flushAudioBuffer(void)
 		notify_wait(&audio_output_client_notify);
 	};
 
-	audio_buffer.position = 0;
-
 	return ret;
 }
 
-static size_t audio_buffer_size(const struct audio_format *af)
-{
-	return audio_format_frame_size(af) * (af->sample_rate >> 5);
-}
-
-static void audio_buffer_resize(size_t size)
-{
-	assert(audio_buffer.position == 0);
-	assert((audio_buffer.size == 0) == (audio_buffer.buffer == NULL));
-
-	if (audio_buffer.size == size)
-		return;
-
-	if (audio_buffer.buffer != NULL)
-		free(audio_buffer.buffer);
-
-	if (size > 0)
-		audio_buffer.buffer = xmalloc(size);
-	else
-		audio_buffer.buffer = NULL;
-
-	audio_buffer.size = size;
-}
-
 int openAudioDevice(const struct audio_format *audioFormat)
 {
 	int ret = -1;
@@ -347,10 +314,8 @@ int openAudioDevice(const struct audio_format *audioFormat)
 
 	if (!audioOpened ||
 	    (audioFormat != NULL && !isCurrentAudioFormat(audioFormat))) {
-		flushAudioBuffer();
 		if (audioFormat != NULL)
 			audio_buffer.format = *audioFormat;
-		audio_buffer_resize(audio_buffer_size(&audio_buffer.format));
 	}
 
 	syncAudioDeviceStates();
@@ -374,30 +339,6 @@ int openAudioDevice(const struct audio_format *audioFormat)
 	return ret;
 }
 
-int playAudio(const char *playChunk, size_t size)
-{
-	size_t send_size;
-
-	while (size > 0) {
-		send_size = audio_buffer.size - audio_buffer.position;
-		send_size = send_size < size ? send_size : size;
-
-		assert(send_size > 0);
-
-		memcpy(audio_buffer.buffer + audio_buffer.position, playChunk, send_size);
-		audio_buffer.position += send_size;
-		size -= send_size;
-		playChunk += send_size;
-
-		if (audio_buffer.position == audio_buffer.size) {
-			if (flushAudioBuffer() < 0)
-				return -1;
-		}
-	}
-
-	return 0;
-}
-
 void audio_output_pause_all(void)
 {
 	unsigned int i;
@@ -416,7 +357,6 @@ void dropBufferedAudio(void)
 	unsigned int i;
 
 	syncAudioDeviceStates();
-	audio_buffer.position = 0;
 
 	for (i = 0; i < audioOutputArraySize; ++i) {
 		if (audio_output_is_open(&audioOutputArray[i]))
@@ -430,13 +370,6 @@ void closeAudioDevice(void)
 {
 	unsigned int i;
 
-	if (audio_buffer.buffer != NULL) {
-		flushAudioBuffer();
-		free(audio_buffer.buffer);
-		audio_buffer.buffer = NULL;
-		audio_buffer.size = 0;
-	}
-
 	for (i = 0; i < audioOutputArraySize; ++i)
 		audio_output_close(&audioOutputArray[i]);