Close #90: add Communicator.on() message with event types.

Author: samchon

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tgrid",
-  "version": "1.0.3",
+  "version": "1.1.0",
   "main": "lib/index.js",
   "typings": "lib/index.d.ts",
   "exports": {

src/components/Communicator.ts

@@ -1,8 +1,9 @@
-import { ConditionVariable, HashMap, Pair } from "tstl";
+import { ConditionVariable, HashMap, HashSet } from "tstl";
 
 import { Driver } from "../typings/Driver";
 import { serializeError } from "../utils/internal/serializeError";
 import { Invoke } from "./Invoke";
+import { InvokeEvent } from "./InvokeEvent";
 
 /**
  * The basic communicator.
@@ -44,7 +45,15 @@ export abstract class Communicator<
   /**
    * @hidden
    */
-  private promises_: HashMap<number, Pair<FunctionLike, FunctionLike>>;
+  private promises_: HashMap<number, IFunctionReservation>;
+
+  /**
+   * @hidden
+   */
+  private event_listeners_: HashMap<
+    InvokeEvent.Type,
+    HashSet<(event: InvokeEvent) => void>
+  >;
 
   /**
    * @hidden
@@ -72,6 +81,50 @@ export abstract class Communicator<
     // OTHER MEMBERS
     this.promises_ = new HashMap();
     this.join_cv_ = new ConditionVariable();
+    this.event_listeners_ = new HashMap();
+  }
+
+  /**
+   * Add invoke event listener.
+   *
+   * Add an event listener for the invoke event. The event listener would be called
+   * when some invoke event has been occured; sending, receiving, completing, or returning.
+   *
+   * If you change the requesting parameters or returning value in the event listener,
+   * it would affect to the RPC (Remote Procedure Call) communication. Therefore, you have
+   * to be careful when modifying the remote function calling.
+   *
+   * Of course, you can utilize the event listener just for monitoring the RPC events.
+   *
+   * @param type Type of the event
+   * @param listener The listener function to enroll
+   */
+  public on<Type extends InvokeEvent.Type>(
+    type: Type,
+    listener: (event: InvokeEvent.EventMapper[Type]) => void,
+  ): void {
+    this.event_listeners_
+      .take(type, () => new HashSet())
+      .insert(listener as (event: InvokeEvent) => void);
+  }
+
+  /**
+   * Erase invoke event listener.
+   *
+   * Erase an event listener from the invoke event. The event listener would not be
+   * called anymore when the specific invoke event has been occured.
+   *
+   * @param type Type of the event
+   * @param listener The listener function to erase
+   */
+  public off<Type extends InvokeEvent.Type>(
+    type: Type,
+    listener: (event: InvokeEvent.EventMapper[Type]) => void,
+  ): void {
+    const it = this.event_listeners_.find(type);
+    if (it.equals(this.event_listeners_.end()) === false)
+      it.second.erase(listener as (event: InvokeEvent) => void);
+    if (it.second.empty()) this.event_listeners_.erase(it);
   }
 
   /**
@@ -93,7 +146,7 @@ export abstract class Communicator<
       : new Error("Connection has been closed.");
 
     for (const entry of this.promises_) {
-      const reject: FunctionLike = entry.second.second;
+      const reject: FunctionLike = entry.second.reject;
       reject(rejectError);
     }
 
@@ -116,7 +169,6 @@ export abstract class Communicator<
    */
   private _Proxy_func(name: string): FunctionLike {
     const func = (...params: any[]) => this._Call_function(name, ...params);
-
     return new Proxy(func, {
       get: ({}, newName: string) => {
         if (newName === "bind")
@@ -125,7 +177,6 @@ export abstract class Communicator<
           return (thisArg: any, ...args: any[]) => func.call(thisArg, ...args);
         else if (newName === "apply")
           return (thisArg: any, args: any[]) => func.apply(thisArg, args);
-
         return this._Proxy_func(`${name}.${newName}`);
       },
     });
@@ -155,8 +206,27 @@ export abstract class Communicator<
         })),
       };
 
+      // CALL EVENT LISTENERS
+      const eventSetIterator = this.event_listeners_.find("send");
+      if (eventSetIterator.equals(this.event_listeners_.end()) === false) {
+        const event: InvokeEvent.ISend = {
+          type: "send",
+          time: new Date(),
+          function: invoke,
+        };
+        for (const listener of eventSetIterator.second)
+          try {
+            listener(event);
+          } catch {}
+      }
+
       // DO SEND WITH PROMISE
-      this.promises_.emplace(invoke.uid, new Pair(resolve, reject));
+      this.promises_.emplace(invoke.uid, {
+        function: invoke,
+        time: new Date(),
+        resolve,
+        reject,
+      });
       await this.sendData(invoke);
     });
   }
@@ -271,14 +341,15 @@ export abstract class Communicator<
   protected replyData(invoke: Invoke): void {
     if ((invoke as Invoke.IFunction).listener)
       this._Handle_function(invoke as Invoke.IFunction).catch(() => {});
-    else this._Handle_return(invoke as Invoke.IReturn);
+    else this._Handle_complete(invoke as Invoke.IReturn);
   }
 
   /**
    * @hidden
    */
   private async _Handle_function(invoke: Invoke.IFunction): Promise<void> {
     const uid: number = invoke.uid;
+    const time: Date = new Date();
 
     try {
       //----
@@ -323,33 +394,80 @@ export abstract class Communicator<
       }
       func = func.bind(thisArg);
 
+      // CALL EVENT LISTENERS
+      const eventSetIterator: HashMap.Iterator<
+        InvokeEvent.Type,
+        HashSet<(event: InvokeEvent) => void>
+      > = this.event_listeners_.find("receive");
+      if (eventSetIterator.equals(this.event_listeners_.end()) === false) {
+        const event: InvokeEvent.IReceive = {
+          type: "receive",
+          time,
+          function: invoke,
+        };
+        for (const closure of eventSetIterator.second)
+          try {
+            closure(event);
+          } catch {}
+      }
+
       //----
       // RETURN VALUE
       //----
       // CALL FUNCTION
       const parameters: any[] = invoke.parameters.map((p) => p.value);
-      const ret: any = await func(...parameters);
-
-      await this._Send_return(uid, true, ret);
+      const result: any = await func(...parameters);
+      await this._Send_return({
+        invoke,
+        time,
+        return: {
+          uid,
+          success: true,
+          value: result,
+        },
+      });
     } catch (exp) {
-      await this._Send_return(uid, false, exp);
+      await this._Send_return({
+        invoke,
+        time,
+        return: {
+          uid,
+          success: false,
+          value: exp,
+        },
+      });
     }
   }
 
   /**
    * @hidden
    */
-  private _Handle_return(invoke: Invoke.IReturn): void {
-    // GET THE PROMISE OBJECT
+  private _Handle_complete(invoke: Invoke.IReturn): void {
+    // FIND TARGET FUNCTION CALL
     const it = this.promises_.find(invoke.uid);
     if (it.equals(this.promises_.end())) return;
 
+    // CALL EVENT LISTENERS
+    const eventSetIterator = this.event_listeners_.find("complete");
+    if (eventSetIterator.equals(this.event_listeners_.end()) === false) {
+      const event: InvokeEvent.IComplete = {
+        type: "complete",
+        function: it.second.function,
+        return: invoke,
+        requested_at: it.second.time,
+        completed_at: new Date(),
+      };
+      for (const closure of eventSetIterator.second)
+        try {
+          closure(event);
+        } catch {}
+    }
+
     // RETURNS
     const func: FunctionLike = invoke.success
-      ? it.second.first
-      : it.second.second;
+      ? it.second.resolve
+      : it.second.reject;
     this.promises_.erase(it);
-
     func(invoke.value);
   }
 
@@ -366,23 +484,39 @@ export abstract class Communicator<
   /**
    * @hidden
    */
-  private async _Send_return(
-    uid: number,
-    success: boolean,
-    value: any,
-  ): Promise<void> {
+  private async _Send_return(props: {
+    invoke: Invoke.IFunction;
+    return: Invoke.IReturn;
+    time: Date;
+  }): Promise<void> {
+    const eventSet = this.event_listeners_.find("return");
+    if (eventSet.equals(this.event_listeners_.end()) === false) {
+      const event: InvokeEvent.IReturn = {
+        type: "return",
+        function: props.invoke,
+        return: props.return,
+        requested_at: props.time,
+        completed_at: new Date(),
+      };
+      for (const closure of eventSet.second)
+        try {
+          closure(event);
+        } catch {}
+    }
+
     // SPECIAL LOGIC FOR ERROR -> FOR CLEAR JSON ENCODING
-    if (success === false && value instanceof Error)
-      value = serializeError(value);
+    if (props.return.success === false && props.return.value instanceof Error)
+      props.return.value = serializeError(props.return.value);
 
     // RETURNS
-    const ret: Invoke.IReturn = {
-      uid,
-      success,
-      value,
-    };
-    await this.sendData(ret);
+    await this.sendData(props.return);
   }
 }
 
 type FunctionLike = (...args: any[]) => any;
+interface IFunctionReservation {
+  function: Invoke.IFunction;
+  time: Date;
+  resolve: FunctionLike;
+  reject: FunctionLike;
+}

src/components/Invoke.ts

@@ -13,12 +13,12 @@ export namespace Invoke {
     /**
      * Unique identifier.
      */
-    uid: number;
+    readonly uid: number;
 
     /**
      * Target function (sometimes calsuled in objects) to call.
      */
-    listener: string;
+    readonly listener: string;
 
     /**
      * Parameters for the function call.
@@ -49,12 +49,12 @@ export namespace Invoke {
     /**
      * Unique identifier.
      */
-    uid: number;
+    readonly uid: number;
 
     /**
      * `true` -> return, `false` -> exception.
      */
-    success: boolean;
+    readonly success: boolean;
 
     /**
      * Returned value or thrown exception.