yeast - npm Package Compare versions

Comparing version 0.0.0 to 0.1.1

index.js

 'use strict';
 
-var seed = 0
+var alphabet = [
+  '0', '1', '2', '3', '4', '5', '6', '7',
+  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
+  'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
+  'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
+  'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
+  'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l',
+  'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
+  'u', 'v', 'w', 'x', 'y', 'z', '-', '_'
+];
+
+var length = alphabet.length
+  , map = {}
+  , seed = 0
+  , i = 0
   , prev;
 
 /**
+ * Return a string representing the specified number.
+ *
+ * @param {Number} num The number to convert.
+ * @returns {String} The string representation of the number.
+ * @api public
+ */
+function encode(num) {
+  var encoded = '';
+
+  do {
+    encoded = alphabet[num % length] + encoded;
+    num = Math.floor(num / length);
+  } while (num > 0);
+
+  return encoded;
+}
+
+/**
+ * Return the integer value specified by the given string.
+ *
+ * @param {String} str The string to convert.
+ * @returns {Number} The integer value represented by the string.
+ * @api public
+ */
+function decode(str) {
+  var decoded = 0
+    , i = 0;
+
+  while (i < str.length) {
+    decoded = decoded * length + map[str.charAt(i)];
+    i++;
+  }
+
+  return decoded;
+}
+
+/**
  * Yeast: A tiny growing id generator.
@@ -12,7 +63,22 @@ *
  */
-module.exports = function yeast() {
-  var now = (+new Date()).toString(36);
+function yeast() {
+  var now = encode(+new Date());
 
   if (now !== prev) return seed = 0, prev = now;
-  return now+':'+ (seed++).toString(36);
-};
+  return now +'.'+ encode(seed++);
+}
+
+//
+// Map each character to its index.
+//
+while (i < length) {
+  map[alphabet[i]] = i;
+  i++;
+}
+
+//
+// Expose the `yeast`, `encode` and `decode` functions.
+//
+yeast.encode = encode;
+yeast.decode = decode;
+module.exports = yeast;

package.json

 {
   "name": "yeast",
-  "version": "0.0.0",
+  "version": "0.1.1",
   "description": "Tiny but linear growing unique id generator",
   "main": "index.js",
   "scripts": {
-    "test": "mocha --reporter spec --ui bdd test.js"
+    "100%": "istanbul check-coverage --statements 100 --functions 100 --lines 100 --branches 100",
+    "test": "mocha test.js",
+    "watch": "mocha --watch test.js",
+    "coverage": "istanbul cover _mocha -- test.js",
+    "test-travis": "istanbul cover _mocha --report lcovonly -- test.js"
   },
@@ -26,6 +30,7 @@ "repository": {
   "devDependencies": {
-    "assume": "0.0.9",
-    "mocha": "2.0.1",
-    "pre-commit": "0.0.9"
+    "assume": "1.2.x",
+    "istanbul": "0.3.x",
+    "mocha": "2.2.x",
+    "pre-commit": "1.1.x"
   }
 }

README.md

 # yeast
 
-Yeast is a unique id generator. It was primary designed to generate a unique id
-which can be used for cache busting in requests. A common practise for this is
-to use a time stamp. But there are couple of down sides when using timestamps.
+[![Made by unshift](https://img.shields.io/badge/made%20by-unshift-00ffcc.svg?style=flat-square)](http://unshift.io)[![Version npm](https://img.shields.io/npm/v/yeast.svg?style=flat-square)](http://browsenpm.org/package/yeast)[![Build Status](https://img.shields.io/travis/unshiftio/yeast/master.svg?style=flat-square)](https://travis-ci.org/unshiftio/yeast)[![Dependencies](https://img.shields.io/david/unshiftio/yeast.svg?style=flat-square)](https://david-dm.org/unshiftio/yeast)[![Coverage Status](https://img.shields.io/coveralls/unshiftio/yeast/master.svg?style=flat-square)](https://coveralls.io/r/unshiftio/yeast?branch=master)[![IRC channel](https://img.shields.io/badge/IRC-irc.freenode.net%23unshift-00a8ff.svg?style=flat-square)](https://webchat.freenode.net/?channels=unshift)
 
-1. The times tamp is already 13 chars long. This might not matter for 1 request
+Yeast is a unique id generator. It has been primary designed to generate a
+unique id which can be used for cache busting. A common practice for this is
+to use a timestamp, but there are couple of downsides when using timestamps.
+
+1. The timestamp is already 13 chars long. This might not matter for 1 request
    but if you make hundreds of them this quickly adds up in bandwidth and
    processing time.
-2. It's not unique enough. If you generate two stamps right after each other the
-   time wouldn't have passed yet so they would be identical.
+2. It's not unique enough. If you generate two stamps right after each other,
+   they would be identical because the timing accuracy is limited to
+   milliseconds.
 
 Yeast solves both of these issues by:
 
-1. Compressing the generated time stamp to a string instead of a number using
-   `toSting(36)`.
-2. Seed the generated id when the previous generated id is the same as the one
-   it just generated.
+1. Compressing the generated timestamp using a custom `encode()` function that
+   returns a string representation of the number.
+2. Seeding the id in case of collision (when the id is identical to the previous
+   one).
 
-To keep the strings unique it will use the `:` char to separate the generated
-stamp from the seed. As we're using `toString(36)` to encode the time stamp you
-can still retrieve the actual time stamp by parsing it again using
-`parseInt(yeastID, 36)`.
+To keep the strings unique it will use the `.` char to separate the generated
+stamp from the seed.
 
@@ -28,3 +29,3 @@ ## Installation
 The module is intended to be used in browsers as well as in Node.js and is
-therefor released in the npm registry and can be installed using:
+therefore released in the npm registry and can be installed using:
 
@@ -37,4 +38,3 @@ ```
 
-This module only exposes one single interface, so when you require yeast it will
-return a function that generates the unique ids:
+All the examples assume that this library is initialized as follow:
 
@@ -45,10 +45,34 @@ ```js
 var yeast = require('yeast');
+```
 
-console.log(yeast(), yeast(), yeast()); // outputs: i24hcpc4 i24hcpc4:0 i24hcpc4:1
+To generate an id just call the `yeast` function.
 
+```js
+console.log(yeast(), yeast(), yeast()); // outputs: KyxidwN KyxidwN:0 KyxidwN:1
+
 setTimeout(function () {
-  console.log(yeast()); // outputs: i24hd9hw
+  console.log(yeast()); // outputs: KyxidwO
 });
 ```
 
+### yeast.encode(num)
+
+An helper function that returns a string representing the specified number. The
+returned string contains only URL safe characters.
+
+```js
+yeast.encode(+new Date()); // outputs: Kyxjuo1
+```
+
+### yeast.decode(str)
+
+An helper function that returns the integer value specified by the given string.
+This function can be used to retrieve the timestamp from a `yeast` id.
+
+```js
+var id = yeast(); // holds the value: Kyxl1OU
+
+yeast.decode(id); // outputs: 1439816226334
+```
+
 That's all folks. If you have ideas on how we can further compress the ids
@@ -59,2 +83,2 @@ please open an issue!
 
-MIT
+[MIT](LICENSE)

No alert changes

Improved metrics

Total package byte prevSize

6553

increased by77.73%

Lines of code

71

increased by54.35%

Number of lines in readme file

81

increased by42.11%

Worsened metrics

Dev dependency count

4

increased by33.33%

Number of package files

4

decreased by-20%

No dependency changes