use send for child process

bcrypt.js

@@ -2,28 +2,40 @@
 'use strict';
 
 var bcrypt = require('bcryptjs'),
-	async = require('async'),
+	async = require('async');
-	action = process.argv[2];
 
-switch(action) {
-	case 'compare':
-			bcrypt.compare(process.argv[3], process.argv[4], function(err, res) {
-				process.stdout.write(res ? 'true' : 'false');
-			});
-		break;
 
-	case 'hash':
+process.on('message', function(msg) {
+	if (msg.type === 'hash') {
+		hashPassword(msg.password, msg.rounds);
+	} else if (msg.type === 'compare') {
+		compare(msg.password, msg.hash);
+	}
+});
+
+function hashPassword(password, rounds) {
 	async.waterfall([
-				async.apply(bcrypt.genSalt, parseInt(process.argv[3], 10)),
+		function(next) {
+			bcrypt.genSalt(parseInt(rounds, 10), next);
+		},
 		function(salt, next) {
-					bcrypt.hash(process.argv[4], salt, next);
+			bcrypt.hash(password, salt, next);
 		}
 	], function(err, hash) {
-				if (!err) {
+		if (err) {
-					process.stdout.write(hash);
+			return process.send({err: err.message});
-				} else {
-					process.stderr.write(err.message);
 		}
+		process.send({result: hash});
+		process.disconnect();
+	});
+}
+
+function compare(password, hash) {
+	bcrypt.compare(password, hash, function(err, res) {
+		if (err) {
+			return process.send({err: err.message});
+		}
+		process.send({result: res});
+		process.disconnect();
  	});
-		break;
 }

src/password.js

@@ -4,34 +4,28 @@
 	var fork = require('child_process').fork;
 
 	module.hash = function(rounds, password, callback) {
-		var child = fork('./bcrypt', ['hash', rounds, password], {
+		forkChild({type: 'hash', rounds: rounds, password: password}, callback);
-				silent: true
-			}),
-			response = '';
-
-		child.stdout.on('data', function(chunk) {
-			response += chunk.toString();
-		});
-
-		child.stdout.on('end', function() {
-			callback(null, response);
-		});
 	};
 
 	module.compare = function(password, hash, callback) {
-		var child = fork('./bcrypt', ['compare', password, hash], {
+		forkChild({type: 'compare', password: password, hash: hash}, callback);
-				silent: true
-			}),
-			response = '';
-
-		child.stdout.on('data', function(chunk) {
-			response += chunk.toString();
-		});
-
-		child.stdout.on('end', function() {
-			callback(null, response === 'true');
-		});
 	};
 
+	function forkChild(message, callback) {
+		var child = fork('./bcrypt', {
+				silent: true
+			});
+
+		child.on('message', function(msg) {
+			if (msg.err) {
+				return callback(new Error(msg.err));
+			}
+
+			callback(null, msg.result);
+		});
+
+		child.send(message);
+	}
+
 	return module;
 })(exports);