mixer/Oss: convert to a class

src/mixer/OssMixerPlugin.cxx

@@ -40,15 +40,24 @@
 
 #define VOLUME_MIXER_OSS_DEFAULT		"/dev/mixer"
 
-struct oss_mixer {
+class OssMixer : public mixer {
-	/** the base mixer class */
-	struct mixer base;
-
 	const char *device;
 	const char *control;
 
 	int device_fd;
 	int volume_control;
+
+public:
+	OssMixer() {
+		mixer_init(this, &oss_mixer_plugin);
+	}
+
+	bool Configure(const config_param *param, GError **error_r);
+	bool Open(GError **error_r);
+	void Close();
+
+	int GetVolume(GError **error_r);
+	bool SetVolume(unsigned volume, GError **error_r);
 };
 
 /**
@@ -75,95 +84,114 @@ oss_find_mixer(const char *name)
 	return -1;
 }
 
+inline bool
+OssMixer::Configure(const config_param *param, GError **error_r)
+{
+	device = config_get_block_string(param, "mixer_device",
+					     VOLUME_MIXER_OSS_DEFAULT);
+	control = config_get_block_string(param, "mixer_control", NULL);
+
+	if (control != NULL) {
+		volume_control = oss_find_mixer(control);
+		if (volume_control < 0) {
+			g_set_error(error_r, oss_mixer_quark(), 0,
+				    "no such mixer control: %s", control);
+			return false;
+		}
+	} else
+		volume_control = SOUND_MIXER_PCM;
+
+	return true;
+}
+
 static struct mixer *
 oss_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param,
 	       GError **error_r)
 {
-	struct oss_mixer *om = g_new(struct oss_mixer, 1);
+	OssMixer *om = new OssMixer();
 
-	mixer_init(&om->base, &oss_mixer_plugin);
+	if (!om->Configure(param, error_r)) {
-
+		delete om;
-	om->device = config_get_block_string(param, "mixer_device",
+		return nullptr;
-					     VOLUME_MIXER_OSS_DEFAULT);
-	om->control = config_get_block_string(param, "mixer_control", NULL);
-
-	if (om->control != NULL) {
-		om->volume_control = oss_find_mixer(om->control);
-		if (om->volume_control < 0) {
-			g_free(om);
-			g_set_error(error_r, oss_mixer_quark(), 0,
-				    "no such mixer control: %s", om->control);
-			return NULL;
 	}
-	} else
-		om->volume_control = SOUND_MIXER_PCM;
 
-	return &om->base;
+	return om;
 }
 
 static void
 oss_mixer_finish(struct mixer *data)
 {
-	struct oss_mixer *om = (struct oss_mixer *) data;
+	OssMixer *om = (OssMixer *) data;
 
-	g_free(om);
+	delete om;
+}
+
+void
+OssMixer::Close()
+{
+	assert(device_fd >= 0);
+
+	close(device_fd);
 }
 
 static void
 oss_mixer_close(struct mixer *data)
 {
-	struct oss_mixer *om = (struct oss_mixer *) data;
+	OssMixer *om = (OssMixer *) data;
+	om->Close();
+}
 
-	assert(om->device_fd >= 0);
+inline bool
+OssMixer::Open(GError **error_r)
+{
+	device_fd = open_cloexec(device, O_RDONLY, 0);
+	if (device_fd < 0) {
+		g_set_error(error_r, oss_mixer_quark(), errno,
+			    "failed to open %s: %s",
+			    device, g_strerror(errno));
+		return false;
+	}
 
-	close(om->device_fd);
+	if (control) {
+		int devmask = 0;
+
+		if (ioctl(device_fd, SOUND_MIXER_READ_DEVMASK, &devmask) < 0) {
+			g_set_error(error_r, oss_mixer_quark(), errno,
+				    "READ_DEVMASK failed: %s",
+				    g_strerror(errno));
+			Close();
+			return false;
+		}
+
+		if (((1 << volume_control) & devmask) == 0) {
+			g_set_error(error_r, oss_mixer_quark(), 0,
+				    "mixer control \"%s\" not usable",
+				    control);
+			Close();
+			return false;
+		}
+	}
+
+	return true;
 }
 
 static bool
 oss_mixer_open(struct mixer *data, GError **error_r)
 {
-	struct oss_mixer *om = (struct oss_mixer *) data;
+	OssMixer *om = (OssMixer *) data;
 
-	om->device_fd = open_cloexec(om->device, O_RDONLY, 0);
+	return om->Open(error_r);
-	if (om->device_fd < 0) {
-		g_set_error(error_r, oss_mixer_quark(), errno,
-			    "failed to open %s: %s",
-			    om->device, g_strerror(errno));
-		return false;
-	}
-
-	if (om->control) {
-		int devmask = 0;
-
-		if (ioctl(om->device_fd, SOUND_MIXER_READ_DEVMASK, &devmask) < 0) {
-			g_set_error(error_r, oss_mixer_quark(), errno,
-				    "READ_DEVMASK failed: %s",
-				    g_strerror(errno));
-			oss_mixer_close(data);
-			return false;
-		}
-
-		if (((1 << om->volume_control) & devmask) == 0) {
-			g_set_error(error_r, oss_mixer_quark(), 0,
-				    "mixer control \"%s\" not usable",
-				    om->control);
-			oss_mixer_close(data);
-			return false;
-		}
-	}
-	return true;
 }
 
-static int
+inline int
-oss_mixer_get_volume(struct mixer *mixer, GError **error_r)
+OssMixer::GetVolume(GError **error_r)
 {
-	struct oss_mixer *om = (struct oss_mixer *)mixer;
 	int left, right, level;
 	int ret;
 
-	assert(om->device_fd >= 0);
+	assert(device_fd >= 0);
 
-	ret = ioctl(om->device_fd, MIXER_READ(om->volume_control), &level);
+	ret = ioctl(device_fd, MIXER_READ(volume_control), &level);
 	if (ret < 0) {
 		g_set_error(error_r, oss_mixer_quark(), errno,
 			    "failed to read OSS volume: %s",
@@ -182,19 +210,25 @@ oss_mixer_get_volume(struct mixer *mixer, GError **error_r)
 	return left;
 }
 
-static bool
+static int
-oss_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
+oss_mixer_get_volume(struct mixer *mixer, GError **error_r)
+{
+	OssMixer *om = (OssMixer *)mixer;
+	return om->GetVolume(error_r);
+}
+
+inline bool
+OssMixer::SetVolume(unsigned volume, GError **error_r)
 {
-	struct oss_mixer *om = (struct oss_mixer *)mixer;
 	int level;
 	int ret;
 
-	assert(om->device_fd >= 0);
+	assert(device_fd >= 0);
 	assert(volume <= 100);
 
 	level = (volume << 8) + volume;
 
-	ret = ioctl(om->device_fd, MIXER_WRITE(om->volume_control), &level);
+	ret = ioctl(device_fd, MIXER_WRITE(volume_control), &level);
 	if (ret < 0) {
 		g_set_error(error_r, oss_mixer_quark(), errno,
 			    "failed to set OSS volume: %s",
@@ -205,6 +239,13 @@ oss_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
 	return true;
 }
 
+static bool
+oss_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
+{
+	OssMixer *om = (OssMixer *)mixer;
+	return om->SetVolume(volume, error_r);
+}
+
 const struct mixer_plugin oss_mixer_plugin = {
 	oss_mixer_init,
 	oss_mixer_finish,