Add rpc handler methods to Room class for convenience (#663)

+---
+"client-sdk-android": patch
+---
+
+Add rpc handler methods to Room class for convenience.

@@ -47,6 +47,7 @@ import io.livekit.android.room.metrics.collectMetrics
 import io.livekit.android.room.network.NetworkCallbackManagerFactory
 import io.livekit.android.room.participant.*
 import io.livekit.android.room.provisions.LKObjects
+import io.livekit.android.room.rpc.RpcManager
 import io.livekit.android.room.track.*
 import io.livekit.android.room.types.toSDKType
 import io.livekit.android.room.util.ConnectionWarmer
@@ -69,6 +70,7 @@ import livekit.org.webrtc.audio.AudioDeviceModule
 import java.net.URI
 import java.util.Date
 import javax.inject.Named
+import kotlin.time.Duration
 
 class Room
 @AssistedInject
@@ -108,7 +110,7 @@ constructor(
     private val connectionWarmer: ConnectionWarmer,
     private val audioRecordPrewarmer: AudioRecordPrewarmer,
     private val incomingDataStreamManager: IncomingDataStreamManager,
-) : RTCEngine.Listener, ParticipantListener, IncomingDataStreamManager by incomingDataStreamManager {
+) : RTCEngine.Listener, ParticipantListener, RpcManager, IncomingDataStreamManager by incomingDataStreamManager {
 
     private lateinit var coroutineScope: CoroutineScope
     private val eventBus = BroadcastEventBus<RoomEvent>()
@@ -1040,6 +1042,19 @@ constructor(
         },
     )
 
+    // ----------------------------------- RpcManager ------------------------------------//
+    override suspend fun registerRpcMethod(method: String, handler: RpcHandler) {
+        localParticipant.registerRpcMethod(method, handler)
+    }
+
+    override fun unregisterRpcMethod(method: String) {
+        localParticipant.unregisterRpcMethod(method)
+    }
+
+    override suspend fun performRpc(destinationIdentity: Participant.Identity, method: String, payload: String, responseTimeout: Duration): String {
+        return localParticipant.performRpc(destinationIdentity, method, payload, responseTimeout)
+    }
+
     // ----------------------------------- RTCEngine.Listener ------------------------------------//
 
     /**

@@ -109,7 +109,9 @@ internal constructor(
     @Named(InjectionNames.SENDER)
     private val capabilitiesGetter: CapabilitiesGetter,
     private val outgoingDataStreamManager: OutgoingDataStreamManager,
-) : Participant(Sid(""), null, coroutineDispatcher), OutgoingDataStreamManager by outgoingDataStreamManager {
+) : Participant(Sid(""), null, coroutineDispatcher),
+    OutgoingDataStreamManager by outgoingDataStreamManager,
+    RpcManager {
 
     var audioTrackCaptureDefaults: LocalAudioTrackOptions by defaultsManager::audioTrackCaptureDefaults
     var audioTrackPublishDefaults: AudioTrackPublishDefaults by defaultsManager::audioTrackPublishDefaults
@@ -988,7 +990,7 @@ internal constructor(
      * @see performRpc
      */
     @Suppress("RedundantSuspendModifier")
-    suspend fun registerRpcMethod(
+    override suspend fun registerRpcMethod(
         method: String,
         handler: RpcHandler,
     ) {
@@ -1000,7 +1002,7 @@ internal constructor(
      *
      * @param method The name of the RPC method to unregister
      */
-    fun unregisterRpcMethod(
+    override fun unregisterRpcMethod(
         method: String,
     ) {
         this.rpcHandlers.remove(method)
@@ -1056,11 +1058,11 @@ internal constructor(
      * @return The response payload.
      * @throws RpcError on failure. Details in [RpcError.message].
      */
-    suspend fun performRpc(
+    override suspend fun performRpc(
         destinationIdentity: Identity,
         method: String,
         payload: String,
-        responseTimeout: Duration = 10.seconds,
+        responseTimeout: Duration,
     ): String = coroutineScope {
         val maxRoundTripLatency = 2.seconds
 

@@ -16,8 +16,78 @@
 
 package io.livekit.android.room.rpc
 
-class RpcManager {
+import io.livekit.android.room.participant.Participant.Identity
+import io.livekit.android.room.participant.RpcHandler
+import io.livekit.android.room.participant.RpcInvocationData
+import io.livekit.android.rpc.RpcError
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.seconds
+
+interface RpcManager {
     companion object {
         const val RPC_VERSION = 1
     }
+
+    /**
+     * Establishes the participant as a receiver for calls of the specified RPC method.
+     * Will overwrite any existing callback for the same method.
+     *
+     * Example:
+     * ```kt
+     * room.registerRpcMethod("greet") { (requestId, callerIdentity, payload, responseTimeout) ->
+     *     Log.i("TAG", "Received greeting from ${callerIdentity}: ${payload}")
+     *
+     *     // Return a string
+     *     "Hello, ${callerIdentity}!"
+     * }
+     * ```
+     *
+     * The handler receives an [RpcInvocationData] with the following parameters:
+     * - `requestId`: A unique identifier for this RPC request
+     * - `callerIdentity`: The identity of the RemoteParticipant who initiated the RPC call
+     * - `payload`: The data sent by the caller (as a string)
+     * - `responseTimeout`: The maximum time available to return a response
+     *
+     * The handler should return a string.
+     * If unable to respond within [RpcInvocationData.responseTimeout], the request will result in an error on the caller's side.
+     *
+     * You may throw errors of type [RpcError] with a string `message` in the handler,
+     * and they will be received on the caller's side with the message intact.
+     * Other errors thrown in your handler will not be transmitted as-is, and will instead arrive to the caller as `1500` ("Application Error").
+     *
+     * @param method The name of the indicated RPC method
+     * @param handler Will be invoked when an RPC request for this method is received
+     * @see RpcHandler
+     * @see RpcInvocationData
+     * @see performRpc
+     */
+    @Suppress("RedundantSuspendModifier")
+    suspend fun registerRpcMethod(
+        method: String,
+        handler: RpcHandler,
+    )
+
+    /**
+     * Unregisters a previously registered RPC method.
+     *
+     * @param method The name of the RPC method to unregister
+     */
+    fun unregisterRpcMethod(method: String)
+
+    /**
+     * Initiate an RPC call to a remote participant
+     * @param destinationIdentity The identity of the destination participant.
+     * @param method The method name to call.
+     * @param payload The payload to pass to the method.
+     * @param responseTimeout Timeout for receiving a response after initial connection.
+     *      Defaults to 10000. Max value of UInt.MAX_VALUE milliseconds.
+     * @return The response payload.
+     * @throws RpcError on failure. Details in [RpcError.message].
+     */
+    suspend fun performRpc(
+        destinationIdentity: Identity,
+        method: String,
+        payload: String,
+        responseTimeout: Duration = 10.seconds,
+    ): String
 }