Rewrite PulseAudio backend into a threaded class

Converts the Mixer PulseAudio backend from a C library to a PaClient
class which runs in its own QThread.  This faciliates isolation of
PaControlModel updates to the QML thread where they belong. It also
provides the foundation for runtime updates of the model and reuse
of the PaClient class in other apps.

AGL-Bug: SPEC-548
Change-Id: I13c4c220fde2fd4bc4aea2e04f39152a963b5fa0
Signed-off-by: Matt Porter <mporter@konsulko.com>

1 files changed, 228 insertions, 0 deletions

diff --git a/app/paclient.cpp b/app/paclient.cpp
new file mode 100644
index 0000000..78567ce
--- /dev/null
+++ b/app/paclient.cpp
@@ -0,0 +1,228 @@
+/*
+ * Copyright (C) 2016,2017 Konsulko Group
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "paclient.h"
+
+#include <QtCore/QDebug>
+
+PaClient::PaClient()
+	: m_init(false), m_ml(nullptr), m_mlapi(nullptr), m_ctx(nullptr)
+{
+}
+
+PaClient::~PaClient()
+{
+	if (m_init)
+		close();
+}
+
+void PaClient::close()
+{
+	if (!m_init) return;
+	pa_threaded_mainloop_stop(m_ml);
+	pa_threaded_mainloop_free(m_ml);
+	m_init = false;
+}
+
+static void set_sink_volume_cb(pa_context *c, int success, void *data __attribute__((unused)))
+{
+	if (!success)
+		qWarning() << "PaClient: set sink volume: " <<
+			pa_strerror(pa_context_errno(c));
+}
+
+static void set_source_volume_cb(pa_context *c, int success, void *data __attribute__((unused)))
+{
+	if (!success)
+		qWarning() << "PaClient: set source volume: " <<
+			pa_strerror(pa_context_errno(c));
+}
+
+void PaClient::setVolume(uint32_t type, uint32_t index, uint32_t channel, uint32_t volume)
+{
+	pa_operation *o;
+	pa_context *c = context();
+	CState *cstate = NULL;
+
+	foreach (cstate, m_cstatelist)
+		if ((cstate->index == index) && (cstate->type == type))
+			break;
+
+	cstate->cvolume.values[channel] = volume;
+
+	if (type == C_SINK) {
+		if (!(o = pa_context_set_sink_volume_by_index(c, index, &cstate->cvolume, set_sink_volume_cb, NULL))) {
+			qWarning() << "PaClient: set sink #" << index <<
+				" channel #" << channel <<
+				" volume: " << pa_strerror(pa_context_errno(c));
+			return;
+		}
+		pa_operation_unref(o);
+	} else if (type == C_SOURCE) {
+		if (!(o = pa_context_set_source_volume_by_index(c, index, &cstate->cvolume, set_source_volume_cb, NULL))) {
+			qWarning() << "PaClient: set source #" << index <<
+				" channel #" << channel <<
+				" volume: " << pa_strerror(pa_context_errno(c));
+			return;
+		}
+		pa_operation_unref(o);
+	}
+}
+
+void get_source_list_cb(pa_context *c,
+		const pa_source_info *i,
+		int eol,
+		void *data)
+{
+	int chan;
+
+	PaClient *self = reinterpret_cast<PaClient*>(data);
+
+	if (eol < 0) {
+		qWarning() << "PaClient: get source list: " <<
+			pa_strerror(pa_context_errno(c));
+
+		self->close();
+		return;
+	}
+
+	if (!eol) {
+		self->addOneControlState(C_SOURCE, i->index, &i->volume);
+		for (chan = 0; chan < i->channel_map.channels; chan++) {
+			emit self->controlAdded(i->index, QString(i->description), C_SOURCE, chan,
+						channel_position_string[i->channel_map.map[chan]],
+						i->volume.values[chan]);
+		}
+	}
+}
+
+void get_sink_list_cb(pa_context *c,
+		const pa_sink_info *i,
+		int eol,
+		void *data)
+{
+	int chan;
+	PaClient *self = reinterpret_cast<PaClient*>(data);
+
+	if(eol < 0) {
+		qWarning() << "PaClient: get sink list: " <<
+			pa_strerror(pa_context_errno(c));
+		self->close();
+		return;
+	}
+
+	if(!eol) {
+		self->addOneControlState(C_SINK, i->index, &i->volume);
+		for (chan = 0; chan < i->channel_map.channels; chan++) {
+			emit self->controlAdded(i->index, QString(i->description), C_SINK, chan,
+						 channel_position_string[i->channel_map.map[chan]],
+						 i->volume.values[chan]);
+		}
+	}
+}
+
+void context_state_cb(pa_context *c, void *data)
+{
+	pa_operation *o;
+	PaClient *self = reinterpret_cast<PaClient*>(data);
+
+	switch (pa_context_get_state(c)) {
+		case PA_CONTEXT_CONNECTING:
+		case PA_CONTEXT_AUTHORIZING:
+		case PA_CONTEXT_SETTING_NAME:
+			break;
+		case PA_CONTEXT_READY:
+			// Fetch the controls of interest
+			if (!(o = pa_context_get_source_info_list(c, get_source_list_cb, data))) {
+				qWarning() << "PaClient: get source info list: " <<
+					pa_strerror(pa_context_errno(c));
+				return;
+			}
+			pa_operation_unref(o);
+			if (!(o = pa_context_get_sink_info_list(c, &get_sink_list_cb, data))) {
+				qWarning() << "PaClient: get sink info list: " <<
+					pa_strerror(pa_context_errno(c));
+				return;
+			}
+			break;
+		case PA_CONTEXT_TERMINATED:
+			self->close();
+			break;
+
+		case PA_CONTEXT_FAILED:
+		default:
+			qCritical() << "PaClient: connection failed: " <<
+				pa_strerror(pa_context_errno(c));
+			self->close();
+			break;
+	}
+}
+
+void PaClient::init()
+{
+	m_ml = pa_threaded_mainloop_new();
+	if (!m_ml) {
+		qCritical("PaClient: failed to create mainloop");
+		return;
+	}
+
+	pa_threaded_mainloop_set_name(m_ml, "PaClient mainloop");
+
+	m_mlapi = pa_threaded_mainloop_get_api(m_ml);
+
+	lock();
+
+	m_ctx = pa_context_new(m_mlapi, "Mixer");
+	if (!m_ctx) {
+		qCritical("PaClient: failed to create context");
+		pa_threaded_mainloop_free(m_ml);
+		return;
+	}
+	pa_context_set_state_callback(m_ctx, context_state_cb, this);
+
+	if (pa_context_connect(m_ctx, 0, (pa_context_flags_t)0, 0) < 0) {
+		qCritical("PaClient: failed to connect");
+		pa_context_unref(m_ctx);
+		pa_threaded_mainloop_free(m_ml);
+		return;
+	}
+
+	if (pa_threaded_mainloop_start(m_ml) != 0) {
+		qCritical("PaClient: failed to start mainloop");
+		pa_context_unref(m_ctx);
+		pa_threaded_mainloop_free(m_ml);
+		return;
+	}
+
+	unlock();
+
+	m_init = true;
+}
+
+void PaClient::addOneControlState(int type, int index, const pa_cvolume *cvolume)
+{
+	int i;
+	CState *cstate;
+
+	cstate = new CState;
+	cstate->type = type;
+	cstate->index = index;
+	cstate->cvolume.channels = cvolume->channels;
+	for (i = 0; i < cvolume->channels; i++)
+		cstate->cvolume.values[i] = cvolume->values[i];
+
+	m_cstatelist.append(cstate);
+}