README.md (2992B)
1 # yeast 2 3 [](http://unshift.io)[](http://browsenpm.org/package/yeast)[](https://travis-ci.org/unshiftio/yeast)[](https://david-dm.org/unshiftio/yeast)[](https://coveralls.io/r/unshiftio/yeast?branch=master)[](https://webchat.freenode.net/?channels=unshift) 4 5 [](https://saucelabs.com/u/yeast) 6 7 Yeast is a unique id generator. It has been primarily designed to generate a 8 unique id which can be used for cache busting. A common practice for this is 9 to use a timestamp, but there are couple of downsides when using timestamps. 10 11 1. The timestamp is already 13 chars long. This might not matter for 1 request 12 but if you make hundreds of them this quickly adds up in bandwidth and 13 processing time. 14 2. It's not unique enough. If you generate two stamps right after each other, 15 they would be identical because the timing accuracy is limited to 16 milliseconds. 17 18 Yeast solves both of these issues by: 19 20 1. Compressing the generated timestamp using a custom `encode()` function that 21 returns a string representation of the number. 22 2. Seeding the id in case of collision (when the id is identical to the previous 23 one). 24 25 To keep the strings unique it will use the `.` char to separate the generated 26 stamp from the seed. 27 28 ## Installation 29 30 The module is intended to be used in browsers as well as in Node.js and is 31 therefore released in the npm registry and can be installed using: 32 33 ``` 34 npm install --save yeast 35 ``` 36 37 ## Usage 38 39 All the examples assume that this library is initialized as follow: 40 41 ```js 42 'use strict'; 43 44 var yeast = require('yeast'); 45 ``` 46 47 To generate an id just call the `yeast` function. 48 49 ```js 50 console.log(yeast(), yeast(), yeast()); // outputs: KyxidwN KyxidwN.0 KyxidwN.1 51 52 setTimeout(function () { 53 console.log(yeast()); // outputs: KyxidwO 54 }); 55 ``` 56 57 ### yeast.encode(num) 58 59 An helper function that returns a string representing the specified number. The 60 returned string contains only URL safe characters. 61 62 ```js 63 yeast.encode(+new Date()); // outputs: Kyxjuo1 64 ``` 65 66 ### yeast.decode(str) 67 68 An helper function that returns the integer value specified by the given string. 69 This function can be used to retrieve the timestamp from a `yeast` id. 70 71 ```js 72 var id = yeast(); // holds the value: Kyxl1OU 73 74 yeast.decode(id); // outputs: 1439816226334 75 ``` 76 77 That's all folks. If you have ideas on how we can further compress the ids 78 please open an issue! 79 80 ## License 81 82 [MIT](LICENSE)