--- /dev/null
+"use strict";
+module.exports = Service;
+
+var util = require("../util/minimal");
+
+// Extends EventEmitter
+(Service.prototype = Object.create(util.EventEmitter.prototype)).constructor = Service;
+
+/**
+ * A service method callback as used by {@link rpc.ServiceMethod|ServiceMethod}.
+ *
+ * Differs from {@link RPCImplCallback} in that it is an actual callback of a service method which may not return `response = null`.
+ * @typedef rpc.ServiceMethodCallback
+ * @template TRes extends Message<TRes>
+ * @type {function}
+ * @param {Error|null} error Error, if any
+ * @param {TRes} [response] Response message
+ * @returns {undefined}
+ */
+
+/**
+ * A service method part of a {@link rpc.Service} as created by {@link Service.create}.
+ * @typedef rpc.ServiceMethod
+ * @template TReq extends Message<TReq>
+ * @template TRes extends Message<TRes>
+ * @type {function}
+ * @param {TReq|Properties<TReq>} request Request message or plain object
+ * @param {rpc.ServiceMethodCallback<TRes>} [callback] Node-style callback called with the error, if any, and the response message
+ * @returns {Promise<Message<TRes>>} Promise if `callback` has been omitted, otherwise `undefined`
+ */
+
+/**
+ * Constructs a new RPC service instance.
+ * @classdesc An RPC service as returned by {@link Service#create}.
+ * @exports rpc.Service
+ * @extends util.EventEmitter
+ * @constructor
+ * @param {RPCImpl} rpcImpl RPC implementation
+ * @param {boolean} [requestDelimited=false] Whether requests are length-delimited
+ * @param {boolean} [responseDelimited=false] Whether responses are length-delimited
+ */
+function Service(rpcImpl, requestDelimited, responseDelimited) {
+
+ if (typeof rpcImpl !== "function")
+ throw TypeError("rpcImpl must be a function");
+
+ util.EventEmitter.call(this);
+
+ /**
+ * RPC implementation. Becomes `null` once the service is ended.
+ * @type {RPCImpl|null}
+ */
+ this.rpcImpl = rpcImpl;
+
+ /**
+ * Whether requests are length-delimited.
+ * @type {boolean}
+ */
+ this.requestDelimited = Boolean(requestDelimited);
+
+ /**
+ * Whether responses are length-delimited.
+ * @type {boolean}
+ */
+ this.responseDelimited = Boolean(responseDelimited);
+}
+
+/**
+ * Calls a service method through {@link rpc.Service#rpcImpl|rpcImpl}.
+ * @param {Method|rpc.ServiceMethod<TReq,TRes>} method Reflected or static method
+ * @param {Constructor<TReq>} requestCtor Request constructor
+ * @param {Constructor<TRes>} responseCtor Response constructor
+ * @param {TReq|Properties<TReq>} request Request message or plain object
+ * @param {rpc.ServiceMethodCallback<TRes>} callback Service callback
+ * @returns {undefined}
+ * @template TReq extends Message<TReq>
+ * @template TRes extends Message<TRes>
+ */
+Service.prototype.rpcCall = function rpcCall(method, requestCtor, responseCtor, request, callback) {
+
+ if (!request)
+ throw TypeError("request must be specified");
+
+ var self = this;
+ if (!callback)
+ return util.asPromise(rpcCall, self, method, requestCtor, responseCtor, request);
+
+ if (!self.rpcImpl) {
+ setTimeout(function() { callback(Error("already ended")); }, 0);
+ return undefined;
+ }
+
+ try {
+ return self.rpcImpl(
+ method,
+ requestCtor[self.requestDelimited ? "encodeDelimited" : "encode"](request).finish(),
+ function rpcCallback(err, response) {
+
+ if (err) {
+ self.emit("error", err, method);
+ return callback(err);
+ }
+
+ if (response === null) {
+ self.end(/* endedByRPC */ true);
+ return undefined;
+ }
+
+ if (!(response instanceof responseCtor)) {
+ try {
+ response = responseCtor[self.responseDelimited ? "decodeDelimited" : "decode"](response);
+ } catch (err) {
+ self.emit("error", err, method);
+ return callback(err);
+ }
+ }
+
+ self.emit("data", response, method);
+ return callback(null, response);
+ }
+ );
+ } catch (err) {
+ self.emit("error", err, method);
+ setTimeout(function() { callback(err); }, 0);
+ return undefined;
+ }
+};
+
+/**
+ * Ends this service and emits the `end` event.
+ * @param {boolean} [endedByRPC=false] Whether the service has been ended by the RPC implementation.
+ * @returns {rpc.Service} `this`
+ */
+Service.prototype.end = function end(endedByRPC) {
+ if (this.rpcImpl) {
+ if (!endedByRPC) // signal end to rpcImpl
+ this.rpcImpl(null, null, null);
+ this.rpcImpl = null;
+ this.emit("end").off();
+ }
+ return this;
+};