Initial binding version

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
Change-Id: I89e493d88c7fa1309f1b2991d346fc496caa6898

1 files changed, 342 insertions, 0 deletions

diff --git a/binding/audiomixer-binding.c b/binding/audiomixer-binding.c
new file mode 100644
index 0000000..005f5c7
--- /dev/null
+++ b/binding/audiomixer-binding.c
@@ -0,0 +1,342 @@
+/*
+ * Copyright © 2019 Collabora Ltd.
+ *   @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <string.h>
+#include <json-c/json.h>
+#include <afb/afb-binding.h>
+#include <systemd/sd-event.h>
+#include "audiomixer.h"
+
+static struct audiomixer *audiomixer;
+static afb_event_t controls_changed;
+static afb_event_t volume_changed;
+static afb_event_t mute_changed;
+static sd_event_source *controls_changed_source;
+
+static int
+audiomixer_controls_changed_deferred(sd_event_source *s, void *data)
+{
+	afb_event_push(controls_changed, NULL);
+
+	sd_event_source_unref(controls_changed_source);
+	controls_changed_source = NULL;
+	return 0;
+}
+
+struct value_changed_data
+{
+	unsigned int change_mask;
+	struct mixer_control control;
+	sd_event_source *source;
+};
+
+static int
+audiomixer_value_changed_deferred(sd_event_source *s, void *data)
+{
+	struct value_changed_data *d = data;
+	json_object *json;
+
+	json = json_object_new_object();
+	json_object_object_add(json, "control",
+		json_object_new_string(d->control.name));
+
+	if (d->change_mask & MIXER_CONTROL_CHANGE_FLAG_VOLUME) {
+		json_object_object_add(json, "value",
+			json_object_new_double(d->control.volume));
+		afb_event_push(volume_changed, json);
+	} else if (d->change_mask & MIXER_CONTROL_CHANGE_FLAG_MUTE) {
+		json_object_object_add(json, "value",
+			json_object_new_int(d->control.mute));
+		afb_event_push(mute_changed, json);
+	}
+
+	sd_event_source_unref(d->source);
+	free(d);
+	return 0;
+}
+
+/* called in audiomixer's thread */
+static void
+audiomixer_controls_changed(void *data)
+{
+	sd_event *e = afb_daemon_get_event_loop();
+	sd_event_add_defer(e, &controls_changed_source,
+		audiomixer_controls_changed_deferred, NULL);
+}
+
+
+/* called in audiomixer's thread */
+static void
+audiomixer_value_changed(void *data,
+	unsigned int change_mask,
+	const struct mixer_control *control)
+{
+	sd_event *e = afb_daemon_get_event_loop();
+	struct value_changed_data *d = calloc(1, sizeof(*d));
+
+	d->change_mask = change_mask;
+	d->control = *control;
+
+	if (sd_event_add_defer(e, &d->source,
+			audiomixer_value_changed_deferred, d) < 0)
+		free(d);
+}
+
+static const struct audiomixer_events audiomixer_events = {
+	.controls_changed = audiomixer_controls_changed,
+	.value_changed = audiomixer_value_changed,
+};
+
+static int
+cleanup(sd_event_source *s, void *data)
+{
+	audiomixer_free(audiomixer);
+	audiomixer = NULL;
+	return 0;
+}
+
+static int
+init(afb_api_t api)
+{
+	sd_event *e = afb_daemon_get_event_loop();
+
+	controls_changed = afb_api_make_event(api, "controls_changed");
+	volume_changed = afb_api_make_event(api, "volume_changed");
+	mute_changed = afb_api_make_event(api, "mute_changed");
+
+	audiomixer = audiomixer_new();
+	sd_event_add_exit(e, NULL, cleanup, NULL);
+
+	audiomixer_add_event_listener(audiomixer, &audiomixer_events, NULL);
+
+	return 0;
+}
+
+static void
+list_controls_cb(afb_req_t request)
+{
+	json_object *ret_json, *nest_json;
+	const struct mixer_control **ctls;
+	unsigned int n_controls, i;
+
+	audiomixer_lock(audiomixer);
+
+	if (audiomixer_ensure_connected(audiomixer, 3) < 0) {
+		afb_req_fail(request, "failed",
+			"Could not connect to the PipeWire daemon");
+		goto unlock;
+	}
+
+	if (audiomixer_ensure_controls(audiomixer, 3) < 0) {
+		AFB_REQ_NOTICE(request, "No mixer controls were exposed "
+			"in PipeWire after 3 seconds");
+	}
+
+	ctls = audiomixer_get_active_controls(audiomixer, &n_controls);
+
+	ret_json = json_object_new_array();
+	for (i = 0; i < n_controls; i++) {
+		nest_json = json_object_new_object();
+		json_object_object_add(nest_json, "control",
+				json_object_new_string(ctls[i]->name));
+		json_object_object_add(nest_json, "volume",
+				json_object_new_double(ctls[i]->volume));
+		json_object_object_add(nest_json, "mute",
+				json_object_new_int(ctls[i]->mute));
+		json_object_array_add(ret_json, nest_json);
+	}
+	afb_req_success(request, ret_json, NULL);
+
+unlock:
+	audiomixer_unlock(audiomixer);
+}
+
+static void
+volume_cb(afb_req_t request)
+{
+	json_object *ret_json;
+	const char *control = afb_req_value(request, "control");
+	const char *value = afb_req_value(request, "value");
+	const struct mixer_control *ctl;
+	double volume;
+
+	audiomixer_lock(audiomixer);
+
+	if (!control) {
+		afb_req_fail(request, "failed",
+			"Invalid arguments: missing 'control'");
+		goto unlock;
+	}
+
+	if (audiomixer_ensure_connected(audiomixer, 3) < 0) {
+		afb_req_fail(request, "failed",
+			"Could not connect to the PipeWire daemon");
+		goto unlock;
+	}
+
+	if (audiomixer_ensure_controls(audiomixer, 3) < 0) {
+		AFB_REQ_NOTICE(request, "No mixer controls were exposed "
+			"in PipeWire after 3 seconds");
+	}
+
+	ctl = audiomixer_find_control(audiomixer, control);
+	if (!ctl) {
+		afb_req_fail(request, "failed", "Could not find control");
+		goto unlock;
+	}
+
+	if(value) {
+		char *endptr;
+		volume = strtod(value, &endptr);
+		if (endptr == value || volume < -0.00001 || volume > 1.00001) {
+			afb_req_fail(request, "failed",
+				"Invalid volume value (must be between 0.0 and 1.0)");
+			goto unlock;
+		}
+
+		audiomixer_change_volume(audiomixer, ctl, volume);
+	} else {
+		volume = ctl->volume;
+	}
+
+	ret_json = json_object_new_object();
+	json_object_object_add(ret_json, "volume", json_object_new_double(volume));
+	afb_req_success(request, ret_json, NULL);
+
+unlock:
+	audiomixer_unlock(audiomixer);
+}
+
+static void
+mute_cb(afb_req_t request)
+{
+	json_object *ret_json;
+	const char *control = afb_req_value(request, "control");
+	const char *value = afb_req_value(request, "value");
+	const struct mixer_control *ctl;
+	int mute;
+
+	audiomixer_lock(audiomixer);
+
+	if (!control) {
+		afb_req_fail(request, "failed",
+			"Invalid arguments: missing 'control'");
+		goto unlock;
+	}
+
+	if (audiomixer_ensure_connected(audiomixer, 3) < 0) {
+		afb_req_fail(request, "failed",
+			"Could not connect to the PipeWire daemon");
+		goto unlock;
+	}
+
+	if (audiomixer_ensure_controls(audiomixer, 3) < 0) {
+		AFB_REQ_NOTICE(request, "No mixer controls were exposed "
+			"in PipeWire after 3 seconds");
+	}
+
+	ctl = audiomixer_find_control(audiomixer, control);
+	if (!ctl) {
+		afb_req_fail(request, "failed", "Could not find control");
+		goto unlock;
+	}
+
+	if(value) {
+		char *endptr;
+		mute = (int) strtol(value, &endptr, 10);
+		if (endptr == value || mute < 0 || mute > 1) {
+			afb_req_fail(request, "failed",
+				"Invalid mute value (must be integer 0 or 1)");
+			goto unlock;
+		}
+
+		audiomixer_change_mute(audiomixer, ctl, mute);
+	} else {
+		mute = ctl->mute;
+	}
+
+	ret_json = json_object_new_object();
+	json_object_object_add(ret_json, "mute", json_object_new_int(mute));
+	afb_req_success(request, ret_json, NULL);
+
+unlock:
+	audiomixer_unlock(audiomixer);
+}
+
+static void
+subscribe_cb(afb_req_t request)
+{
+	const char *eventstr = afb_req_value(request, "event");
+	afb_event_t event;
+
+	if (!eventstr) {
+		afb_req_fail(request, "failed",
+			"Invalid arguments: missing 'event'");
+		return;
+	}
+
+	if (!strcmp(eventstr, "controls_changed"))
+		event = controls_changed;
+	else if (!strcmp(eventstr, "volume_changed"))
+		event = volume_changed;
+	else if (!strcmp(eventstr, "mute_changed"))
+		event = mute_changed;
+	else {
+		afb_req_fail(request, "failed", "Invalid event name");
+		return;
+	}
+
+	if (afb_req_subscribe(request, event) != 0)
+		afb_req_fail(request, "failed", "Failed to subscribe to event");
+	else
+		afb_req_success(request, NULL, "Subscribed");
+}
+
+static void
+unsubscribe_cb(afb_req_t request)
+{
+	const char *eventstr = afb_req_value(request, "event");
+	afb_event_t event;
+
+	if (!eventstr) {
+		afb_req_fail(request, "failed",
+			"Invalid arguments: missing 'event'");
+		return;
+	}
+
+	if (!strcmp(eventstr, "controls_changed"))
+		event = controls_changed;
+	else if (!strcmp(eventstr, "volume_changed"))
+		event = volume_changed;
+	else if (!strcmp(eventstr, "mute_changed"))
+		event = mute_changed;
+	else {
+		afb_req_fail(request, "failed", "Invalid event name");
+		return;
+	}
+
+	if (afb_req_unsubscribe(request, event) != 0)
+		afb_req_fail(request, "failed", "Failed to unsubscribe from event");
+	else
+		afb_req_success(request, NULL, "Unsubscribed");
+}
+
+static const afb_verb_t verbs[]= {
+	{ .verb = "list_controls", .callback = list_controls_cb, .info = "List the available controls" },
+	{ .verb = "volume",        .callback = volume_cb,        .info = "Get/Set volume" },
+	{ .verb = "mute",          .callback = mute_cb,          .info = "Get/Set mute" },
+	{ .verb = "subscribe",     .callback = subscribe_cb,     .info = "Subscribe to mixer events" },
+	{ .verb = "unsubscribe",   .callback = unsubscribe_cb,   .info = "Unsubscribe from mixer events" },
+	{ }
+};
+
+const afb_binding_t afbBindingV3 = {
+	.api  = "audiomixer",
+	.specification = "AudioMixer API",
+	.verbs = verbs,
+	.init = init,
+};