update

node_modules/backo2/index.js

@@ -0,0 +1,85 @@
+
+/**
+ * Expose `Backoff`.
+ */
+
+module.exports = Backoff;
+
+/**
+ * Initialize backoff timer with `opts`.
+ *
+ * - `min` initial timeout in milliseconds [100]
+ * - `max` max timeout [10000]
+ * - `jitter` [0]
+ * - `factor` [2]
+ *
+ * @param {Object} opts
+ * @api public
+ */
+
+function Backoff(opts) {
+  opts = opts || {};
+  this.ms = opts.min || 100;
+  this.max = opts.max || 10000;
+  this.factor = opts.factor || 2;
+  this.jitter = opts.jitter > 0 && opts.jitter <= 1 ? opts.jitter : 0;
+  this.attempts = 0;
+}
+
+/**
+ * Return the backoff duration.
+ *
+ * @return {Number}
+ * @api public
+ */
+
+Backoff.prototype.duration = function(){
+  var ms = this.ms * Math.pow(this.factor, this.attempts++);
+  if (this.jitter) {
+    var rand =  Math.random();
+    var deviation = Math.floor(rand * this.jitter * ms);
+    ms = (Math.floor(rand * 10) & 1) == 0  ? ms - deviation : ms + deviation;
+  }
+  return Math.min(ms, this.max) | 0;
+};
+
+/**
+ * Reset the number of attempts.
+ *
+ * @api public
+ */
+
+Backoff.prototype.reset = function(){
+  this.attempts = 0;
+};
+
+/**
+ * Set the minimum duration
+ *
+ * @api public
+ */
+
+Backoff.prototype.setMin = function(min){
+  this.ms = min;
+};
+
+/**
+ * Set the maximum duration
+ *
+ * @api public
+ */
+
+Backoff.prototype.setMax = function(max){
+  this.max = max;
+};
+
+/**
+ * Set the jitter
+ *
+ * @api public
+ */
+
+Backoff.prototype.setJitter = function(jitter){
+  this.jitter = jitter;
+};
+