Add retry_max_delay option

- add option
- add test

index.js

@@ -51,11 +51,14 @@ function RedisClient(stream, options) {
     if (options.connect_timeout && !isNaN(options.connect_timeout) && options.connect_timeout > 0) {
         this.connect_timeout = +options.connect_timeout;
     }
-
     this.enable_offline_queue = true;
     if (typeof this.options.enable_offline_queue === "boolean") {
         this.enable_offline_queue = this.options.enable_offline_queue;
     }
+	this.retry_max_delay = null;
+	if (options.retry_max_delay !== undefined && !isNaN(options.retry_max_delay) && options.retry_max_delay > 0) {
+		this.retry_max_delay = options.retry_max_delay;
+	}
 
     this.initialize_retry_vars();
     this.pub_sub_mode = false;
@@ -429,7 +432,11 @@ RedisClient.prototype.connection_gone = function (why) {
         return;
     }
 
+	if (this.retry_max_delay !== null && this.retry_delay > this.retry_max_delay) {
+		this.retry_delay = this.retry_max_delay;
+	} else {
 		this.retry_delay = Math.floor(this.retry_delay * this.retry_backoff);
+	}
 
     if (exports.debug_mode) {
         console.log("Retry connection in " + this.retry_delay + " ms");

test.js

@@ -1798,6 +1798,28 @@ tests.auth = function () {
     });
 };
 
+tests.reconnectRetryMaxDelay = function() {
+	var time = new Date().getTime(),
+		name = 'reconnectRetryMaxDelay',
+		reconnecting = false;
+	var client = redis.createClient(PORT, HOST, {
+		retry_max_delay: 1
+	});
+	client.on('ready', function() {
+		if (!reconnecting) {
+			reconnecting = true;
+			client.retry_delay = 1000;
+			client.retry_backoff = 1;
+			client.stream.end();
+		} else {
+			client.end();
+			var lasted = new Date().getTime() - time;
+			assert.ok(lasted < 1000);
+			next(name);
+		}
+	});
+};
+
 all_tests = Object.keys(tests);
 all_start = new Date();
 test_count = 0;