output: make "struct audio_output" opaque for output plugins

We have eliminated direct accesses to the audio_output struct from
the all output plugins.  Make it opaque for them, and move its real
declaration to output_internal.h, similar to decoder_internal.h.

Pass the opaque structure to plugin.init() only, which will return the
plugin's data pointer on success, and NULL on failure.  This data
pointer will be passed to all other methods instead of the
audio_output struct.

1 files changed, 27 insertions, 30 deletions

diff --git a/src/audioOutputs/audioOutput_jack.c b/src/audioOutputs/audioOutput_jack.c
index 14b1e92e4..f817bd435 100644
--- a/src/audioOutputs/audioOutput_jack.c
+++ b/src/audioOutputs/audioOutput_jack.c
@@ -29,6 +29,8 @@
 static const size_t sample_size = sizeof(jack_default_audio_sample_t);
 
 typedef struct _JackData {
+	struct audio_output *ao;
+
 	/* configuration */
 	const char *name;
 	const char *output_ports[2];
@@ -90,9 +92,8 @@ static void freeJackClient(JackData *jd)
 	pthread_cond_destroy(&jd->play_audio);
 }
 
-static void freeJackData(struct audio_output *audioOutput)
+static void freeJackData(JackData *jd)
 {
-	JackData *jd = audioOutput->data;
 	int i;
 
 	assert(jd != NULL);
@@ -111,15 +112,16 @@ static void freeJackData(struct audio_output *audioOutput)
 	free(jd);
 }
 
-static void jack_finishDriver(struct audio_output *audioOutput)
+static void jack_finishDriver(void *data)
 {
-	freeJackData(audioOutput);
+	JackData *jd = data;
+	freeJackData(jd);
 	DEBUG("disconnect_jack (pid=%d)\n", getpid ());
 }
 
 static int srate(mpd_unused jack_nframes_t rate, void *data)
 {
-	JackData *jd = (JackData *) ((struct audio_output *) data)->data;
+	JackData *jd = (JackData *)data;
 	struct audio_format *audioFormat = jd->audio_format;
 
  	audioFormat->sampleRate = (int)jack_get_sample_rate(jd->client);
@@ -182,11 +184,8 @@ static void shutdown_callback(void *arg)
 	jd->shutdown = 1;
 }
 
-static void set_audioformat(struct audio_output *audioOutput,
-			    struct audio_format *audioFormat)
+static void set_audioformat(JackData *jd, struct audio_format *audioFormat)
 {
-	JackData *jd = audioOutput->data;
-
 	audioFormat->sampleRate = (int) jack_get_sample_rate(jd->client);
 	DEBUG("samplerate = %d\n", audioFormat->sampleRate);
 	audioFormat->channels = 2;
@@ -201,9 +200,9 @@ static void error_callback(const char *msg)
 	ERROR("jack: %s\n", msg);
 }
 
-static int jack_initDriver(struct audio_output *audioOutput,
-			   mpd_unused const struct audio_format *audio_format,
-			   ConfigParam *param)
+static void *jack_initDriver(struct audio_output *ao,
+			     mpd_unused const struct audio_format *audio_format,
+			     ConfigParam *param)
 {
 	JackData *jd;
 	BlockParam *bp;
@@ -211,11 +210,12 @@ static int jack_initDriver(struct audio_output *audioOutput,
 	int val;
 	char *cp = NULL;
 
-	audioOutput->data = newJackData();
-	jd = audioOutput->data;
+	jd = newJackData();
+	jd->ao = ao;
 
 	DEBUG("jack_initDriver (pid=%d)\n", getpid());
-	if ( ! param ) return 0;
+	if (param == NULL)
+		return jd;
 
 	if ( (bp = getBlockParam(param, "ports")) ) {
 		DEBUG("output_ports=%s\n", bp->value);
@@ -261,7 +261,7 @@ static int jack_initDriver(struct audio_output *audioOutput,
 		DEBUG("name=%s\n", jd->name);
 	}
 
- 	return 0;
+	return jd;
 }
 
 static int jack_testDefault(void)
@@ -269,10 +269,8 @@ static int jack_testDefault(void)
 	return 0;
 }
 
-static int connect_jack(struct audio_output *audioOutput,
-			struct audio_format *audio_format)
+static int connect_jack(JackData *jd, struct audio_format *audio_format)
 {
-	JackData *jd = audioOutput->data;
 	const char **jports;
 	char *port_name;
 
@@ -286,7 +284,7 @@ static int connect_jack(struct audio_output *audioOutput,
 	jack_set_error_function(error_callback);
 	jack_set_process_callback(jd->client, process, (void *)jd);
 	jack_set_sample_rate_callback(jd->client, (JackProcessCallback)srate,
-				      (void *)audioOutput);
+				      (void *)jd);
 	jack_on_shutdown(jd->client, shutdown_callback, (void *)jd);
 
 	if ( jack_activate(jd->client) ) {
@@ -353,40 +351,39 @@ static int connect_jack(struct audio_output *audioOutput,
 	return 1;
 }
 
-static int jack_openDevice(struct audio_output *audioOutput,
+static int jack_openDevice(void *data,
 			   struct audio_format *audio_format)
 {
-	JackData *jd = audioOutput->data;
+	JackData *jd = data;
 
 	assert(jd != NULL);
 
-	if (jd->client == NULL && connect_jack(audioOutput,
-					       audio_format) < 0) {
+	if (jd->client == NULL && connect_jack(jd, audio_format) < 0) {
 		freeJackClient(jd);
 		return -1;
 	}
 
-	set_audioformat(audioOutput, audio_format);
+	set_audioformat(jd, audio_format);
 
 	DEBUG("jack_openDevice (pid=%d)!\n", getpid ());
 	return 0;
 }
 
 
-static void jack_closeDevice(mpd_unused struct audio_output *audioOutput)
+static void jack_closeDevice(mpd_unused void *data)
 {
 	/*jack_finishDriver(audioOutput);*/
 	DEBUG("jack_closeDevice (pid=%d)\n", getpid());
 }
 
-static void jack_dropBufferedAudio (mpd_unused struct audio_output *audioOutput)
+static void jack_dropBufferedAudio (mpd_unused void *data)
 {
 }
 
-static int jack_playAudio(struct audio_output *audioOutput,
+static int jack_playAudio(void *data,
 			  const char *buff, size_t size)
 {
-	JackData *jd = audioOutput->data;
+	JackData *jd = data;
 	size_t space;
 	size_t i;
 	const short *buffer = (const short *) buff;
@@ -398,7 +395,7 @@ static int jack_playAudio(struct audio_output *audioOutput,
 	if ( jd->shutdown ) {
 		ERROR("Refusing to play, because there is no client thread.\n");
 		freeJackClient(jd);
-		audio_output_closed(audioOutput);
+		audio_output_closed(jd->ao);
 		return 0;
 	}