Added watchForUpgrade()

Author: ionut.stan

package.json

@@ -1,7 +1,7 @@
 {
   "name": "jsonrpc-bidirectional",
   "description": "Bidirectional JSONRPC over web sockets or HTTP with extensive plugin support.",
-  "version": "5.6.7",
+  "version": "5.7.0",
   "scripts": {
     "build": "node build.js",
     "test": "node --expose-gc --max-old-space-size=1024 tests/main.js",
@@ -35,6 +35,7 @@
   },
   "dependencies": {
     "extendable-error-class": "^0.1.1",
+    "fs-promise": "^2.0.3",
     "node-fetch": "^1.6.3",
     "sleep-promise": "^2.0.0"
   },

src/NodeClusterBase/MasterEndpoint.js

@@ -1,5 +1,7 @@
 const cluster = require("cluster");
 const os = require("os");
+const assert = require("assert");
+const fs = require("fs-promise");
 
 const sleep = require("sleep-promise");
 const JSONRPC = {
@@ -47,6 +49,7 @@ class MasterEndpoint extends JSONRPC.EndpointBase
 		this.objWorkerIDToState = {};
 
 		this._bWorkersStarted = false;
+		this._bWatchingForUpgrade = false;
 	}
 
 
@@ -146,6 +149,64 @@ class MasterEndpoint extends JSONRPC.EndpointBase
 	}
 
 
+	/**
+	 * If the version in package.json changes, this.gracefulExit() will be invoked.
+	 * 
+	 * @param {string} strPackageJSONPath
+	 * 
+	 * @returns {undefined}
+	 */
+	async watchForUpgrade(strPackageJSONPath)
+	{
+		assert(typeof strPackageJSONPath === "string");
+
+		if(this._bWatchingForUpgrade)
+		{
+			return;
+		}
+
+		this._bWatchingForUpgrade = true;
+
+		const strVersion = JSON.parse(await fs.readFile(strPackageJSONPath, "utf8")).version;
+		let nPackageJSONModificationTime = (await fs.stat(strPackageJSONPath)).mtime.getTime();
+		let strVersionNew = strVersion;
+
+		const nIntervalMilliseconds = 10 * 1000;
+
+		const nIntervalID = setInterval(
+			async () => {
+				try
+				{
+					if(nPackageJSONModificationTime !== (await fs.stat(strPackageJSONPath)).mtime.getTime())
+					{
+						nPackageJSONModificationTime = (await fs.stat(strPackageJSONPath)).mtime.getTime();
+						strVersionNew = JSON.parse(await fs.readFile(strPackageJSONPath, "utf8")).version;
+					}
+
+					if(strVersionNew !== strVersion)
+					{
+						clearInterval(nIntervalID);
+
+						console.log(`
+							Updated. 
+							Detected new version ${strVersionNew}. 
+							Old version ${strVersion}. 
+							Attempting to exit gracefully to allow starting with new version.
+						`.replace(/^\t+/gm, ""));
+
+						await this.gracefulExit(null);
+					}
+				}
+				catch(error)
+				{
+					console.error(error);
+				}
+			},
+			nIntervalMilliseconds
+		);
+	}
+
+
 	/**
 	 * Signals a worker's JSONRPC endpoint is ready to receive calls.
 	 * 

src/NodeClusterBase/WorkerClient.js

@@ -13,7 +13,7 @@ class WorkerClient extends JSONRPC.Client
 	 */
 	async gracefulExit()
 	{
-		return this.rpc("gracefulExit", []);
+		return this.rpc("gracefulExit", [], /*bNotification*/ true);
 	}
 };
 

src/Plugins/Client/WorkerTransport.js

@@ -178,7 +178,6 @@ class WorkerTransport extends JSONRPC.ClientPluginBase
 	 */
 	async beforeJSONDecode(outgoingRequest)
 	{
-		outgoingRequest.responseObject = outgoingRequest.responseBody;
 	}
 
 

tests/main_NodeClusterBase.js

@@ -1,8 +1,12 @@
 const JSONRPC = require("..");
+
 const cluster = require("cluster");
 const assert = require("assert");
+const path = require("path");
+
 const sleep = require("sleep-promise");
 
+
 process.on(
 	"unhandledRejection", 
 	(reason, promise) => 
@@ -33,6 +37,7 @@ setInterval(() => {}, 10000);
 		{
 			const endpoint = new JSONRPC.NodeClusterBase.MasterEndpoint(JSONRPC.NodeClusterBase.WorkerClient);
 			await endpoint.start();
+			await endpoint.watchForUpgrade(path.join(path.dirname(__dirname), "package.json"));
 
 			let bNotReady;
 			console.log("Waiting for workers to all signal they are ready.");
@@ -62,7 +67,7 @@ setInterval(() => {}, 10000);
 			assert(await endpoint.masterClient.ping("Test") === "Test", "Calling MasterEndpoint.ping() returned the wrong thing.");
 
 			console.log("Will call masterClient.gracefulExit().");
-			await sleep(4000);
+			await sleep(40000);
 			// This will call all worker's gracefulExit() methods.
 			await endpoint.masterClient.gracefulExit();
 		}