mixer/{alsa,pulse}: convert to C++

1 files changed, 433 insertions, 0 deletions

diff --git a/src/mixer/AlsaMixerPlugin.cxx b/src/mixer/AlsaMixerPlugin.cxx
new file mode 100644
index 00000000..6623d12e
--- /dev/null
+++ b/src/mixer/AlsaMixerPlugin.cxx
@@ -0,0 +1,433 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "mixer_api.h"
+#include "output_api.h"
+#include "event_pipe.h"
+
+#include <glib.h>
+#include <alsa/asoundlib.h>
+
+#define VOLUME_MIXER_ALSA_DEFAULT		"default"
+#define VOLUME_MIXER_ALSA_CONTROL_DEFAULT	"PCM"
+#define VOLUME_MIXER_ALSA_INDEX_DEFAULT		0
+
+struct alsa_mixer_source {
+	GSource source;
+
+	snd_mixer_t *mixer;
+
+	/** a linked list of all registered GPollFD objects */
+	GSList *fds;
+};
+
+struct alsa_mixer {
+	/** the base mixer class */
+	struct mixer base;
+
+	const char *device;
+	const char *control;
+	unsigned int index;
+
+	snd_mixer_t *handle;
+	snd_mixer_elem_t *elem;
+	long volume_min;
+	long volume_max;
+	int volume_set;
+
+	struct alsa_mixer_source *source;
+};
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+alsa_mixer_quark(void)
+{
+	return g_quark_from_static_string("alsa_mixer");
+}
+
+/*
+ * GSource helper functions
+ *
+ */
+
+static GSList **
+find_fd(GSList **list_r, int fd)
+{
+	while (true) {
+		GSList *list = *list_r;
+		if (list == NULL)
+			return NULL;
+
+		GPollFD *p = (GPollFD *)list->data;
+		if (p->fd == fd)
+			return list_r;
+
+		list_r = &list->next;
+	}
+}
+
+static void
+alsa_mixer_update_fd(struct alsa_mixer_source *source, const struct pollfd *p,
+		     GSList **old_r)
+{
+	GSList **found_r = find_fd(old_r, p->fd);
+	if (found_r == NULL) {
+		/* new fd */
+		GPollFD *q = g_new(GPollFD, 1);
+		q->fd = p->fd;
+		q->events = p->events;
+		g_source_add_poll(&source->source, q);
+		source->fds = g_slist_prepend(source->fds, q);
+		return;
+	}
+
+	GSList *found = *found_r;
+	*found_r = found->next;
+
+	GPollFD *q = (GPollFD *)found->data;
+	if (q->events != p->events) {
+		/* refresh events */
+		g_source_remove_poll(&source->source, q);
+		q->events = p->events;
+		g_source_add_poll(&source->source, q);
+	}
+
+	found->next = source->fds;
+	source->fds = found;
+}
+
+static void
+alsa_mixer_update_fds(struct alsa_mixer_source *source)
+{
+	int count = snd_mixer_poll_descriptors_count(source->mixer);
+	if (count < 0)
+		count = 0;
+
+	struct pollfd *pfds = g_new(struct pollfd, count);
+	count = snd_mixer_poll_descriptors(source->mixer, pfds, count);
+	if (count < 0)
+		count = 0;
+
+	GSList *old = source->fds;
+	source->fds = NULL;
+
+	for (int i = 0; i < count; ++i)
+		alsa_mixer_update_fd(source, &pfds[i], &old);
+	g_free(pfds);
+
+	for (; old != NULL; old = old->next) {
+		GPollFD *q = (GPollFD *)old->data;
+		g_source_remove_poll(&source->source, q);
+		g_free(q);
+	}
+
+	g_slist_free(old);
+}
+
+/*
+ * GSource methods
+ *
+ */
+
+static gboolean
+alsa_mixer_source_prepare(GSource *_source, G_GNUC_UNUSED gint *timeout_r)
+{
+	struct alsa_mixer_source *source = (struct alsa_mixer_source *)_source;
+	alsa_mixer_update_fds(source);
+
+	return false;
+}
+
+static gboolean
+alsa_mixer_source_check(GSource *_source)
+{
+	struct alsa_mixer_source *source = (struct alsa_mixer_source *)_source;
+
+	for (const GSList *i = source->fds; i != NULL; i = i->next) {
+		const GPollFD *poll_fd = (GPollFD *)i->data;
+		if (poll_fd->revents != 0)
+			return true;
+	}
+
+	return false;
+}
+
+static gboolean
+alsa_mixer_source_dispatch(GSource *_source,
+			   G_GNUC_UNUSED GSourceFunc callback,
+			   G_GNUC_UNUSED gpointer user_data)
+{
+	struct alsa_mixer_source *source = (struct alsa_mixer_source *)_source;
+
+	snd_mixer_handle_events(source->mixer);
+	return true;
+}
+
+static void
+alsa_mixer_source_finalize(GSource *_source)
+{
+	struct alsa_mixer_source *source = (struct alsa_mixer_source *)_source;
+
+	for (GSList *i = source->fds; i != NULL; i = i->next)
+		g_free(i->data);
+
+	g_slist_free(source->fds);
+}
+
+static GSourceFuncs alsa_mixer_source_funcs = {
+	alsa_mixer_source_prepare,
+	alsa_mixer_source_check,
+	alsa_mixer_source_dispatch,
+	alsa_mixer_source_finalize,
+	nullptr,
+	nullptr,
+};
+
+/*
+ * libasound callbacks
+ *
+ */
+
+static int
+alsa_mixer_elem_callback(G_GNUC_UNUSED snd_mixer_elem_t *elem, unsigned mask)
+{
+	if (mask & SND_CTL_EVENT_MASK_VALUE)
+		event_pipe_emit(PIPE_EVENT_MIXER);
+
+	return 0;
+}
+
+/*
+ * mixer_plugin methods
+ *
+ */
+
+static struct mixer *
+alsa_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param,
+		G_GNUC_UNUSED GError **error_r)
+{
+	struct alsa_mixer *am = g_new(struct alsa_mixer, 1);
+
+	mixer_init(&am->base, &alsa_mixer_plugin);
+
+	am->device = config_get_block_string(param, "mixer_device",
+					     VOLUME_MIXER_ALSA_DEFAULT);
+	am->control = config_get_block_string(param, "mixer_control",
+					      VOLUME_MIXER_ALSA_CONTROL_DEFAULT);
+	am->index = config_get_block_unsigned(param, "mixer_index",
+					      VOLUME_MIXER_ALSA_INDEX_DEFAULT);
+
+	return &am->base;
+}
+
+static void
+alsa_mixer_finish(struct mixer *data)
+{
+	struct alsa_mixer *am = (struct alsa_mixer *)data;
+
+	g_free(am);
+
+	/* free libasound's config cache */
+	snd_config_update_free_global();
+}
+
+G_GNUC_PURE
+static snd_mixer_elem_t *
+alsa_mixer_lookup_elem(snd_mixer_t *handle, const char *name, unsigned idx)
+{
+	for (snd_mixer_elem_t *elem = snd_mixer_first_elem(handle);
+	     elem != NULL; elem = snd_mixer_elem_next(elem)) {
+		if (snd_mixer_elem_get_type(elem) == SND_MIXER_ELEM_SIMPLE &&
+		    g_ascii_strcasecmp(snd_mixer_selem_get_name(elem),
+				       name) == 0 &&
+		    snd_mixer_selem_get_index(elem) == idx)
+			return elem;
+	}
+
+	return NULL;
+}
+
+static bool
+alsa_mixer_setup(struct alsa_mixer *am, GError **error_r)
+{
+	int err;
+
+	if ((err = snd_mixer_attach(am->handle, am->device)) < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "failed to attach to %s: %s",
+			    am->device, snd_strerror(err));
+		return false;
+	}
+
+	if ((err = snd_mixer_selem_register(am->handle, NULL,
+		    NULL)) < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "snd_mixer_selem_register() failed: %s",
+			    snd_strerror(err));
+		return false;
+	}
+
+	if ((err = snd_mixer_load(am->handle)) < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "snd_mixer_load() failed: %s\n",
+			    snd_strerror(err));
+		return false;
+	}
+
+	am->elem = alsa_mixer_lookup_elem(am->handle, am->control, am->index);
+	if (am->elem == NULL) {
+		g_set_error(error_r, alsa_mixer_quark(), 0,
+			    "no such mixer control: %s", am->control);
+		return false;
+	}
+
+	snd_mixer_selem_get_playback_volume_range(am->elem,
+						  &am->volume_min,
+						  &am->volume_max);
+
+	snd_mixer_elem_set_callback(am->elem, alsa_mixer_elem_callback);
+
+	am->source = (struct alsa_mixer_source *)
+		g_source_new(&alsa_mixer_source_funcs, sizeof(*am->source));
+	am->source->mixer = am->handle;
+	am->source->fds = NULL;
+	g_source_attach(&am->source->source, g_main_context_default());
+
+	return true;
+}
+
+static bool
+alsa_mixer_open(struct mixer *data, GError **error_r)
+{
+	struct alsa_mixer *am = (struct alsa_mixer *)data;
+	int err;
+
+	am->volume_set = -1;
+
+	err = snd_mixer_open(&am->handle, 0);
+	if (err < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "snd_mixer_open() failed: %s", snd_strerror(err));
+		return false;
+	}
+
+	if (!alsa_mixer_setup(am, error_r)) {
+		snd_mixer_close(am->handle);
+		return false;
+	}
+
+	return true;
+}
+
+static void
+alsa_mixer_close(struct mixer *data)
+{
+	struct alsa_mixer *am = (struct alsa_mixer *)data;
+
+	assert(am->handle != NULL);
+
+	g_source_destroy(&am->source->source);
+	g_source_unref(&am->source->source);
+
+	snd_mixer_elem_set_callback(am->elem, NULL);
+	snd_mixer_close(am->handle);
+}
+
+static int
+alsa_mixer_get_volume(struct mixer *mixer, GError **error_r)
+{
+	struct alsa_mixer *am = (struct alsa_mixer *)mixer;
+	int err;
+	int ret;
+	long level;
+
+	assert(am->handle != NULL);
+
+	err = snd_mixer_handle_events(am->handle);
+	if (err < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "snd_mixer_handle_events() failed: %s",
+			    snd_strerror(err));
+		return false;
+	}
+
+	err = snd_mixer_selem_get_playback_volume(am->elem,
+						  SND_MIXER_SCHN_FRONT_LEFT,
+						  &level);
+	if (err < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "failed to read ALSA volume: %s",
+			    snd_strerror(err));
+		return false;
+	}
+
+	ret = ((am->volume_set / 100.0) * (am->volume_max - am->volume_min)
+	       + am->volume_min) + 0.5;
+	if (am->volume_set > 0 && ret == level) {
+		ret = am->volume_set;
+	} else {
+		ret = (int)(100 * (((float)(level - am->volume_min)) /
+				   (am->volume_max - am->volume_min)) + 0.5);
+	}
+
+	return ret;
+}
+
+static bool
+alsa_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
+{
+	struct alsa_mixer *am = (struct alsa_mixer *)mixer;
+	float vol;
+	long level;
+	int err;
+
+	assert(am->handle != NULL);
+
+	vol = volume;
+
+	am->volume_set = vol + 0.5;
+
+	level = (long)(((vol / 100.0) * (am->volume_max - am->volume_min) +
+			am->volume_min) + 0.5);
+	level = level > am->volume_max ? am->volume_max : level;
+	level = level < am->volume_min ? am->volume_min : level;
+
+	err = snd_mixer_selem_set_playback_volume_all(am->elem, level);
+	if (err < 0) {
+		g_set_error(error_r, alsa_mixer_quark(), err,
+			    "failed to set ALSA volume: %s",
+			    snd_strerror(err));
+		return false;
+	}
+
+	return true;
+}
+
+const struct mixer_plugin alsa_mixer_plugin = {
+	alsa_mixer_init,
+	alsa_mixer_finish,
+	alsa_mixer_open,
+	alsa_mixer_close,
+	alsa_mixer_get_volume,
+	alsa_mixer_set_volume,
+	true,
+};