Own live camera sessions in an Android foreground service

tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamController.kt

@@ -0,0 +1,99 @@
+package com.utun.chat.data
+
+import android.content.Intent
+import android.os.Handler
+import android.os.Looper
+import android.widget.Toast
+import androidx.core.content.ContextCompat
+import com.utun.chat.ChatApplication
+import com.utun.chat.R
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import java.util.concurrent.atomic.AtomicLong
+
+enum class StreamPhase { STARTING, LIVE, STOPPING, ENDED, FAILED }
+data class StreamState(val id: Long, val group: Long, val phase: StreamPhase, val error: Int? = null) {
+    val ongoing get() = phase == StreamPhase.STARTING || phase == StreamPhase.LIVE || phase == StreamPhase.STOPPING
+}
+
+/** Один владелец публикации на процесс. StateFlow и service lifecycle — main thread; camera/audio не держат UI. */
+object StreamController {
+    private val ids = AtomicLong(System.nanoTime().coerceAtLeast(1))
+    fun nextId(): Long = ids.incrementAndGet()
+    private val main = Handler(Looper.getMainLooper())
+    private val mutable = MutableStateFlow<StreamState?>(null)
+    val state: StateFlow<StreamState?> = mutable
+    @Volatile var capturing = false
+        private set
+    private var service: StreamService? = null
+
+    fun start(group: Long, camera: String, audio: Boolean, rotation: Int) {
+        check(Looper.myLooper() == Looper.getMainLooper())
+        if (mutable.value?.ongoing == true) { LogManager.addLog("WARN", "stream", "publisher already owned"); return }
+        val id = nextId()
+        if (!NativeLib.isReady() || group == 0L || CallController.state.value?.ongoing == true ||
+            RadioAudioEngine.instance().isActive() || NativeLib.voiceIsActive()) {
+            LogManager.addLog("WARN", "stream", "start rejected: core/call/radio/voice busy group=$group")
+            mutable.value = StreamState(id, group, StreamPhase.FAILED, R.string.stream_resources_busy); return
+        }
+        capturing = true; mutable.value = StreamState(id, group, StreamPhase.STARTING)
+        try {
+            ContextCompat.startForegroundService(ChatApplication.instance, Intent(ChatApplication.instance, StreamService::class.java)
+                .putExtra("id", id).putExtra("group", group).putExtra("camera", camera).putExtra("audio", audio).putExtra("rotation", rotation))
+        } catch (e: Exception) {
+            LogManager.addLog("ERROR", "stream", "service start failed id=$id: ${e.message}")
+            capturing = false; mutable.value = StreamState(id, group, StreamPhase.FAILED, R.string.stream_failed)
+        }
+    }
+
+    fun serviceReady(id: Long, owner: StreamService): Boolean {
+        if (mutable.value?.id != id || mutable.value?.phase != StreamPhase.STARTING) return false
+        service = owner; return true
+    }
+
+    fun opened(id: Long) {
+        val st = mutable.value ?: return
+        if (st.id == id && st.phase == StreamPhase.STARTING) mutable.value = st.copy(phase = StreamPhase.LIVE)
+    }
+
+    fun failed(id: Long, detail: String) {
+        main.post {
+            val st = mutable.value ?: return@post
+            if (st.id != id || !st.ongoing) return@post
+            LogManager.addLog("ERROR", "stream", "publisher failed id=$id $detail")
+            mutable.value = st.copy(error = R.string.stream_failed); stop()
+        }
+    }
+
+    fun stop() {
+        val st = mutable.value ?: return
+        if (!st.ongoing || st.phase == StreamPhase.STOPPING) return
+        mutable.value = st.copy(phase = StreamPhase.STOPPING)
+        service?.shutdown() // До onStartCommand отменённый start завершит foreground-handshake и остановится.
+    }
+
+    fun ended(id: Long, owner: StreamService) {
+        if (service === owner) service = null
+        val st = mutable.value ?: return
+        if (st.id != id) return
+        capturing = false
+        mutable.value = st.copy(phase = if (st.error != null) StreamPhase.FAILED else StreamPhase.ENDED)
+        LogManager.addLog("INFO", "stream", "publisher released id=$id")
+    }
+
+    fun reset() {
+        val st = mutable.value
+        if (st?.ongoing == true) {
+            mutable.value = st.copy(phase = StreamPhase.STOPPING, error = R.string.stream_failed)
+            service?.shutdown(abort = true)
+        }
+    }
+
+    /** Звонок/рация/голосовое не отбирают микрофон у foreground-трансляции. */
+    fun blocksCapture(): Boolean {
+        if (!capturing) return false
+        LogManager.addLog("WARN", "stream", "microphone/camera owned by stream id=${mutable.value?.id}")
+        main.post { Toast.makeText(AppLanguage.context(), R.string.stream_resources_busy, Toast.LENGTH_SHORT).show() }
+        return true
+    }
+}

tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamService.kt

@@ -0,0 +1,113 @@
+package com.utun.chat.data
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.app.Service
+import android.content.Intent
+import android.content.pm.ServiceInfo
+import android.os.Build
+import android.os.IBinder
+import android.os.PowerManager
+import androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import com.utun.chat.MainActivity
+import com.utun.chat.R
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+/** Foreground-владелец камеры, микрофона и CPU lock; не восстанавливает live session после смерти процесса. */
+class StreamService : Service() {
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate)
+    private var capture: StreamCaptureEngine? = null
+    private var lock: PowerManager.WakeLock? = null
+    private var id = 0L
+    private var stopping = false
+    private var aborting = false
+    private var poll: Job? = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent?.action == "stop") { StreamController.stop(); return START_NOT_STICKY }
+        if (id != 0L) return START_NOT_STICKY
+        id = intent?.getLongExtra("id", 0) ?: 0
+        val audio = intent?.getBooleanExtra("audio", true) ?: true
+        try {
+            val notifications = getSystemService(NotificationManager::class.java)
+            notifications.createNotificationChannel(NotificationChannel("live_stream", getString(R.string.stream_title), NotificationManager.IMPORTANCE_LOW))
+            val open = PendingIntent.getActivity(this, 0, Intent(this, MainActivity::class.java), PendingIntent.FLAG_IMMUTABLE)
+            val stop = PendingIntent.getService(this, 0, Intent(this, StreamService::class.java).setAction("stop"), PendingIntent.FLAG_IMMUTABLE)
+            val notification = NotificationCompat.Builder(this, "live_stream").setSmallIcon(android.R.drawable.ic_menu_camera)
+                .setContentTitle(getString(R.string.stream_live)).setContentIntent(open).setOngoing(true)
+                .addAction(android.R.drawable.ic_media_pause, getString(R.string.stream_stop), stop).build()
+            val type = if (Build.VERSION.SDK_INT >= 30) ServiceInfo.FOREGROUND_SERVICE_TYPE_CAMERA or
+                (if (audio) ServiceInfo.FOREGROUND_SERVICE_TYPE_MICROPHONE else 0) else 0
+            ServiceCompat.startForeground(this, 1004, notification, type)
+            if (id == 0L || !StreamController.serviceReady(id, this)) { finish(); return START_NOT_STICKY }
+            lock = getSystemService(PowerManager::class.java).newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "utun:live_stream").apply {
+                setReferenceCounted(false); acquire()
+            }
+            val group = intent!!.getLongExtra("group", 0)
+            capture = StreamCaptureEngine(this, id, group, intent.getStringExtra("camera") ?: error("Missing camera"),
+                audio, intent.getIntExtra("rotation", 0)) { detail -> StreamController.failed(id, detail) }.also { it.start() }
+            poll = scope.launch {
+                val deadline = System.nanoTime() + 10_000_000_000
+                var opened = false
+                while (true) {
+                    val event = NativeLib.streamPull(id)
+                    if (event != null) when (event[0].toInt()) {
+                        4 -> { opened = true; StreamController.opened(id) }
+                        5 -> { finish(); return@launch }
+                        6 -> { StreamController.failed(id, "native session closed"); shutdown(abort = true); return@launch }
+                    }
+                    if (!NativeLib.isReady() || (!opened && System.nanoTime() > deadline)) {
+                        StreamController.failed(id, "core stopped/open timeout"); shutdown(abort = true); return@launch
+                    }
+                    delay(20)
+                }
+            }
+            LogManager.addLog("INFO", "stream", "foreground started id=$id group=$group microphone=$audio CPU lock=${lock?.isHeld}")
+        } catch (e: Exception) {
+            StreamController.failed(id, "foreground service: ${e.message}")
+            shutdown(abort = true)
+        }
+        return START_NOT_STICKY
+    }
+
+    /** Producers завершатся до FIN; при уничтожении ядра очередь не ждём. */
+    fun shutdown(abort: Boolean = false) {
+        aborting = aborting || abort
+        if (stopping) return
+        stopping = true
+        val engine = capture
+        if (engine == null) { NativeLib.streamStop(id); finish(); return }
+        engine.stop {
+            scope.launch {
+                capture = null; NativeLib.streamStop(id)
+                if (aborting) finish()
+                else scope.launch { delay(4000); if (stopping) finish() }
+            }
+        }
+    }
+
+    private fun finish() {
+        poll?.cancel(); poll = null
+        lock?.let { if (it.isHeld) it.release() }; lock = null
+        StreamController.ended(id, this)
+        stopForeground(STOP_FOREGROUND_REMOVE); stopSelf()
+    }
+
+    override fun onDestroy() {
+        poll?.cancel()
+        capture?.stop { NativeLib.streamStop(id) }; capture = null
+        lock?.let { if (it.isHeld) it.release() }; lock = null
+        StreamController.ended(id, this); scope.cancel()
+        LogManager.addLog("INFO", "stream", "foreground destroyed id=$id")
+        super.onDestroy()
+    }
+    override fun onBind(intent: Intent?): IBinder? = null
+}