Fix get timestamp

Readme.md

@@ -71,7 +71,7 @@ same as MongoId.parse(id.toString()), see below
 
 #### id.getTimestamp( )
 
-same as MongoId.getTimestam(id.toString()), see below
+same as MongoId.getTimestamp(id.toString()), see below
 
 #### id.toString( )
 

mongoid.js

@@ -3,7 +3,7 @@
  * Ids are a hex number built out of the timestamp, a per-server unique id,
  * the process id and a sequence number.
  *
- * Copyright (C) 2014 Andras Radics
+ * Copyright (C) 2014,2016 Andras Radics
  * Licensed under the Apache License, Version 2.0
  *
  * MongoDB object ids are 12 bytes (24 hexadecimal chars), composed out of
@@ -64,8 +64,10 @@ var timestampCache = (function() {
         if (!_timestamp || ++_ncalls > 1000) {
             _ncalls = 0;
             _timestamp = Date.now();
-            _timestampStr = hexFormat(Math.floor(_timestamp/1000), 8);
-            setTimeout(function(){ _timestamp = null; }, 10);
+            var msToNextTimestamp = 1000 - _timestamp % 1000;
+            setTimeout(function(){ _timestamp = null; }, Math.min(msToNextTimestamp - 1, 100));
+            _timestamp -= _timestamp % 1000;
+            _timestampStr = hexFormat(_timestamp/1000, 8);
         }
         return _timestampStr;
     }
@@ -76,7 +78,9 @@ MongoId.prototype._getTimestampStr = timestampCache[1];
 
 var _hexDigits = ['0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'];
 MongoId.prototype.fetch = function() {
+    this.sequenceId += 1;
     if (this.sequenceId >= 0x1000000) {
+        // sequence wrapped, we can make an id only if the timestamp advanced
         var _timestamp = this._getTimestamp();
         if (_timestamp === this.sequenceStartTimestamp) {
             // TODO: find a more elegant way to deal with overflow
@@ -86,8 +90,8 @@ MongoId.prototype.fetch = function() {
         this.sequenceStartTimestamp = _timestamp;
     }
 
-    if (++this.sequenceId % 16 === 0) {
-        this.sequencePrefix = hexFormat((this.sequenceId / 16 | 0).toString(16), 5);
+    if ((this.sequenceId & 0xF) === 0) {
+        this.sequencePrefix = hexFormat((this.sequenceId >>> 4).toString(16), 5);
     }
     return this._getTimestampStr() + this.processIdStr + this.sequencePrefix + _hexDigits[this.sequenceId % 16];
 };
@@ -124,7 +128,7 @@ MongoId.prototype.parse = function( idstring ) {
 MongoId.getTimestamp = function( idstring ) {
     return parseInt(idstring.slice(0, 8), 16) * 1000;
 };
-MongoId.prototype.getTimestamp = function( idstring ) {
+MongoId.prototype.getTimestamp = function( ) {
     return MongoId.getTimestamp(this.toString());
 };
 

test/test-mongoid.js

@@ -57,7 +57,7 @@ module.exports.require = {
 module.exports.mongoid_function = {
     testShouldReturn24CharHexString: function(test) {
         var id = mongoid();
-        test.ok(id.match(/[0-9a-fA-F]{24}/), "should return a 24-char id string");
+        test.ok(id.match(/^[0-9a-fA-F]{24}$/), "should return a 24-char id string");
         test.done();
     },
 
@@ -76,6 +76,26 @@ module.exports.mongoid_function = {
         test.ok(t2-t1 < 100, "should generate > 100k ids / sec");
         test.done();
     },
+
+    'should throw Error if wrapped in same second': function(t) {
+        factory = new MongoId(0x111111);
+        factory.sequenceId = 0xffffff;
+        factory.sequencePrefix = "fffff";
+        // note: race condition: this test will fail if the seconds increase before the fetch
+        t.throws(function(){ factory.fetch() }, 'should throw');
+        t.done();
+    },
+
+    'should wrap at max id': function(t) {
+        factory = new MongoId(0x222222);
+        factory.sequenceId = 0xfffffe;
+        factory.sequencePrefix = "fffff";
+        factory.sequenceStartTimestamp -= 1000;
+        t.equal(factory.fetch().slice(-6), 'ffffff');
+        t.equal(factory.fetch().slice(-6), '000000');
+        t.equal(factory.fetch().slice(-6), '000001');
+        t.done();
+    },
 };
 
 module.exports.MongoId_class = {