use size_t and constant pointer in ao plugins

The audio output plugins should get a constant pointer, because they
must not modify the buffer.  Since the size is a non-negative buffer
size in bytes, we should change its type to size_t.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7293 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/audioOutput.c

@@ -181,8 +181,8 @@ int openAudioOutput(AudioOutput * audioOutput, AudioFormat * audioFormat)
 	return ret;
 }
 
-static void convertAudioFormat(AudioOutput * audioOutput, char **chunkArgPtr,
-			       int *sizeArgPtr)
+static void convertAudioFormat(AudioOutput * audioOutput,
+			       const char **chunkArgPtr, size_t *sizeArgPtr)
 {
 	size_t size = pcm_sizeOfConvBuffer(&(audioOutput->inAudioFormat),
 					   *sizeArgPtr,
@@ -203,7 +203,8 @@ static void convertAudioFormat(AudioOutput * audioOutput, char **chunkArgPtr,
 	*chunkArgPtr = audioOutput->convBuffer;
 }
 
-int playAudioOutput(AudioOutput * audioOutput, char *playChunk, int size)
+int playAudioOutput(AudioOutput * audioOutput,
+		    const char *playChunk, size_t size)
 {
 	int ret;
 

src/audioOutput.h

@@ -43,7 +43,7 @@ typedef void (*AudioOutputFinishDriverFunc) (AudioOutput * audioOutput);
 typedef int (*AudioOutputOpenDeviceFunc) (AudioOutput * audioOutput);
 
 typedef int (*AudioOutputPlayFunc) (AudioOutput * audioOutput,
-				    char *playChunk, int size);
+				    const char *playChunk, size_t size);
 
 typedef void (*AudioOutputDropBufferedAudioFunc) (AudioOutput * audioOutput);
 
@@ -97,7 +97,8 @@ void unloadAudioOutputPlugin(AudioOutputPlugin * audioOutputPlugin);
 
 int initAudioOutput(AudioOutput *, ConfigParam * param);
 int openAudioOutput(AudioOutput * audioOutput, AudioFormat * audioFormat);
-int playAudioOutput(AudioOutput * audioOutput, char *playChunk, int size);
+int playAudioOutput(AudioOutput * audioOutput,
+		    const char *playChunk, size_t size);
 void dropBufferedAudioOutput(AudioOutput * audioOutput);
 void closeAudioOutput(AudioOutput * audioOutput);
 void finishAudioOutput(AudioOutput * audioOutput);

src/audioOutputs/audioOutput_alsa.c

@@ -381,7 +381,8 @@ static void alsa_closeDevice(AudioOutput * audioOutput)
 	audioOutput->open = 0;
 }
 
-static int alsa_playAudio(AudioOutput * audioOutput, char *playChunk, int size)
+static int alsa_playAudio(AudioOutput * audioOutput,
+			  const char *playChunk, size_t size)
 {
 	AlsaData *ad = audioOutput->data;
 	int ret;

src/audioOutputs/audioOutput_ao.c

@@ -199,19 +199,37 @@ static int audioOutputAo_openDevice(AudioOutput * audioOutput)
 	return 0;
 }
 
-static int audioOutputAo_play(AudioOutput * audioOutput, char *playChunk,
-			      int size)
+/**
+ * For whatever reason, libao wants a non-const pointer.  Let's hope
+ * it does not write to the buffer, and use the union deconst hack to
+ * work around this API misdesign.
+ */
+static int ao_play_deconst(ao_device *device, const void *output_samples,
+			   uint_32 num_bytes)
 {
-	int send;
+	union {
+		const void *in;
+		void *out;
+	} u;
+
+	u.in = output_samples;
+	return ao_play(device, u.out, num_bytes);
+}
+
+static int audioOutputAo_play(AudioOutput * audioOutput,
+			      const char *playChunk, size_t size)
+{
+	size_t send;
 	AoData *ad = (AoData *) audioOutput->data;
 
 	if (ad->device == NULL)
 		return -1;
 
 	while (size > 0) {
-		send = ad->writeSize > size ? size : ad->writeSize;
+		send = (size_t)ad->writeSize > size
+			? size : (size_t)ad->writeSize;
 
-		if (ao_play(ad->device, playChunk, send) == 0) {
+		if (ao_play_deconst(ad->device, playChunk, send) == 0) {
 			audioOutputAo_error();
 			ERROR("closing audio device due to write error\n");
 			audioOutputAo_closeDevice(audioOutput);

src/audioOutputs/audioOutput_fifo.c

@@ -234,11 +234,12 @@ static void fifo_dropBufferedAudio(AudioOutput *audioOutput)
 	}
 }
 
-static int fifo_playAudio(AudioOutput *audioOutput, char *playChunk, int size)
+static int fifo_playAudio(AudioOutput *audioOutput,
+			  const char *playChunk, size_t size)
 {
 	FifoData *fd = (FifoData *)audioOutput->data;
-	int offset = 0;
-	int bytes;
+	size_t offset = 0;
+	ssize_t bytes;
 
 	if (!fd->timer->started)
 		timer_start(fd->timer);

src/audioOutputs/audioOutput_jack.c

@@ -368,12 +368,13 @@ static void jack_dropBufferedAudio (AudioOutput * audioOutput)
 {
 }
 
-static int jack_playAudio(AudioOutput * audioOutput, char *buff, int size)
+static int jack_playAudio(AudioOutput * audioOutput,
+			  const char *buff, size_t size)
 {
 	JackData *jd = audioOutput->data;
 	size_t space;
-	unsigned int i;
-	short *buffer = (short *) buff;
+	size_t i;
+	const short *buffer = (const short *) buff;
 	jack_default_audio_sample_t sample;
 	size_t samples = size/4;
 

src/audioOutputs/audioOutput_mvp.c

@@ -231,10 +231,11 @@ static void mvp_dropBufferedAudio(AudioOutput * audioOutput)
 	}
 }
 
-static int mvp_playAudio(AudioOutput * audioOutput, char *playChunk, int size)
+static int mvp_playAudio(AudioOutput * audioOutput,
+			 const char *playChunk, size_t size)
 {
 	MvpData *md = audioOutput->data;
-	int ret;
+	ssize_t ret;
 
 	/* reopen the device since it was closed by dropBufferedAudio */
 	if (md->fd < 0)

src/audioOutputs/audioOutput_null.c

@@ -42,7 +42,8 @@ static void null_closeDevice(AudioOutput *audioOutput)
 	audioOutput->open = 0;
 }
 
-static int null_playAudio(AudioOutput *audioOutput, char *playChunk, int size)
+static int null_playAudio(AudioOutput *audioOutput,
+			  const char *playChunk, size_t size)
 {
 	Timer *timer = audioOutput->data;
 

src/audioOutputs/audioOutput_oss.c

@@ -521,10 +521,11 @@ static void oss_dropBufferedAudio(AudioOutput * audioOutput)
 	}
 }
 
-static int oss_playAudio(AudioOutput * audioOutput, char *playChunk, int size)
+static int oss_playAudio(AudioOutput * audioOutput,
+			 const char *playChunk, size_t size)
 {
 	OssData *od = audioOutput->data;
-	int ret;
+	ssize_t ret;
 
 	/* reopen the device since it was closed by dropBufferedAudio */
 	if (od->fd < 0 && oss_open(audioOutput) < 0)

src/audioOutputs/audioOutput_osx.c

@@ -29,9 +29,9 @@ typedef struct _OsxData {
 	pthread_mutex_t mutex;
 	pthread_cond_t condition;
 	char *buffer;
-	int bufferSize;
-	int pos;
-	int len;
+	size_t bufferSize;
+	size_t pos;
+	size_t len;
 	int started;
 } OsxData;
 
@@ -141,8 +141,8 @@ static OSStatus osx_render(void *vdata,
 {
 	OsxData *od = (OsxData *) vdata;
 	AudioBuffer *buffer = &bufferList->mBuffers[0];
-	int bufferSize = buffer->mDataByteSize;
-	int bytesToCopy;
+	size_t bufferSize = buffer->mDataByteSize;
+	size_t bytesToCopy;
 	int curpos = 0;
 
 	/*DEBUG("osx_render: enter : %i\n", (int)bufferList->mNumberBuffers);
@@ -186,7 +186,7 @@ static OSStatus osx_render(void *vdata,
 	od->len -= bytesToCopy;
 
 	if (od->pos + bytesToCopy > od->bufferSize) {
-		int bytes = od->bufferSize - od->pos;
+		size_t bytes = od->bufferSize - od->pos;
 		memcpy(buffer->mData + curpos, od->buffer + od->pos, bytes);
 		od->pos = 0;
 		curpos += bytes;
@@ -294,11 +294,12 @@ static int osx_openDevice(AudioOutput * audioOutput)
 	return 0;
 }
 
-static int osx_play(AudioOutput * audioOutput, char *playChunk, int size)
+static int osx_play(AudioOutput * audioOutput,
+		    const char *playChunk, size_t size)
 {
 	OsxData *od = (OsxData *) audioOutput->data;
-	int bytesToCopy;
-	int curpos;
+	size_t bytesToCopy;
+	size_t curpos;
 
 	/* DEBUG("osx_play: enter\n"); */
 
@@ -333,7 +334,7 @@ static int osx_play(AudioOutput * audioOutput, char *playChunk, int size)
 		od->len += bytesToCopy;
 
 		if (curpos + bytesToCopy > od->bufferSize) {
-			int bytes = od->bufferSize - curpos;
+			size_t bytes = od->bufferSize - curpos;
 			memcpy(od->buffer + curpos, playChunk, bytes);
 			curpos = 0;
 			playChunk += bytes;

src/audioOutputs/audioOutput_pulse.c

@@ -182,7 +182,8 @@ static void pulse_closeDevice(AudioOutput * audioOutput)
 	audioOutput->open = 0;
 }
 
-static int pulse_playAudio(AudioOutput * audioOutput, char *playChunk, int size)
+static int pulse_playAudio(AudioOutput * audioOutput,
+			   const char *playChunk, size_t size)
 {
 	PulseData *pd;
 	int error;

src/audioOutputs/audioOutput_shout.c

@@ -597,12 +597,14 @@ static void myShout_sendMetadata(ShoutData * sd)
 	sd->tagToSend = 0;
 }
 
-static int myShout_play(AudioOutput * audioOutput, char *playChunk, int size)
+static int myShout_play(AudioOutput * audioOutput,
+			const char *playChunk, size_t size)
 {
-	int i, j;
+	unsigned int i;
+	int j;
 	ShoutData *sd = (ShoutData *) audioOutput->data;
 	float **vorbbuf;
-	int samples;
+	unsigned int samples;
 	int bytes = sd->audioFormat->bits / 8;
 	int status;