From 7ac62d3cdb89ffd22aec04f8d89dbb6e6a4e6568 Mon Sep 17 00:00:00 2001
From: Ivo Julca <ivojulca@hotmail.com>
Date: Wed, 23 Mar 2016 02:22:23 -0500
Subject: [PATCH] Refactor Verifier to use the PM API

---
 app.js      |  1 +
 verifier.js | 85 +++++++++++++++++++++++++++--------------------------
 2 files changed, 45 insertions(+), 41 deletions(-)

diff --git a/app.js b/app.js
index 0a4df73a63..a52f3b3c1f 100644
--- a/app.js
+++ b/app.js
@@ -115,6 +115,7 @@ global.Rooms = require('./rooms.js');
 
 delete process.send; // in case we're a child process
 global.Verifier = require('./verifier.js');
+Verifier.PM.spawn();
 
 global.CommandParser = require('./command-parser.js');
 
diff --git a/verifier.js b/verifier.js
index d8848bdea5..a8151dd2a2 100644
--- a/verifier.js
+++ b/verifier.js
@@ -14,55 +14,58 @@
 
 'use strict';
 
-// Because I don't want two files, we're going to fork ourselves.
+const crypto = require('crypto');
+const ProcessManager = require('./process-manager');
 
-if (!process.send) {
-	// This is the parent
+const PM = exports.PM = new ProcessManager({
+	maxProcesses: 1,
+	execFile: 'verifier.js',
+	onMessageUpstream: function (message) {
+		// Protocol:
+		// success: "[id]|1"
+		// failure: "[id]|0"
+		let pipeIndex = message.indexOf('|');
+		let id = +message.substr(0, pipeIndex);
+		let result = Boolean(~~message.slice(pipeIndex + 1));
 
-	let guid = 1;
-	let resolvers = Object.create(null);
-
-	let child = exports.child = require('child_process').fork('verifier.js', {cwd: __dirname});
-
-	exports.verify = function (data, signature) {
-		return new Promise((resolve, reject) => {
-			let localGuid = guid++;
-			resolvers[localGuid] = resolve;
-			child.send({data: data, sig: signature, guid: localGuid});
-		});
-	};
-
-	child.on('message', response => {
-		if (response.guid in resolvers) {
-			resolvers[response.guid](response.success);
-			delete resolvers[response.guid];
+		if (this.pendingTasks.has(id)) {
+			this.pendingTasks.get(id)(result);
+			this.pendingTasks.delete(id);
+			this.release();
 		}
-	});
-} else {
-	// This is the child
+	},
+	onMessageDownstream: function (message) {
+		// protocol:
+		// "[id]|{data, sig}"
+		let pipeIndex = message.indexOf('|');
+		let id = message.substr(0, pipeIndex);
 
-	global.Config = require('./config/config.js');
-	let crypto = require('crypto');
-
-	let keyalgo = Config.loginserverkeyalgo;
-	let pkey = Config.loginserverpublickey;
-
-	process.on('message', message => {
-		let verifier = crypto.createVerify(keyalgo);
-		verifier.update(message.data);
+		let data = JSON.parse(message.slice(pipeIndex + 1));
+		process.send(id + '|' + this.receive(data));
+	},
+	receive: function (data) {
+		let verifier = crypto.createVerify(Config.loginserverkeyalgo);
+		verifier.update(data.data);
 		let success = false;
 		try {
-			success = verifier.verify(pkey, message.sig, 'hex');
+			success = verifier.verify(Config.loginserverpublickey, data.sig, 'hex');
 		} catch (e) {}
-		process.send({
-			success: success,
-			guid: message.guid,
-		});
-	});
 
-	process.on('disconnect', () => {
-		process.exit();
-	});
+		return success ? 1 : 0;
+	},
+});
+
+if (process.send && module === process.mainModule) {
+	// This is a child process!
+
+	global.Config = require('./config/config.js');
 
 	require('./repl.js').start('verifier', cmd => eval(cmd));
+
+	process.on('message', message => PM.onMessageDownstream(message));
+	process.on('disconnect', () => process.exit());
 }
+
+exports.verify = function (data, signature) {
+	return PM.send({data: data, sig: signature});
+};