Image-cache NPM

image-cache

Powerful image cache for NodeJS

What is image-cache?

image-cache is nodejs module for cache image and serve with base64 format. image-cache using Asynchronous calls for best Performance.

New

Now image-cache using google proxy cache for best caching.

Installation

to install image-cache on your project, you can use NPM and Yarn with the following command,

NPM

npm install --save image-cache

Yarn

yarn add image-cache

Usage

Start using image-cache

var imageCache = require('image-cache');

API

setOptions

is a function to replace options from default options. this function not returning something. for using this function, add this code after defining all variable.

imageCache.setOptions({
   compressed: false

   // write your custom options here
});

API

Key	Data Type	Default Value	Description
`dir`	`string`	`path.join(__dirname, 'cache/')`	directory root for cached files
`compressed`	`boolean`	true	compressing cache output with zlib compressing maybe can make your processing cache little bit longer. for example without compressing is 6-7ms when using compressing is 150-185ms, but your cache file is a litle bit smaller than without compressing
`extname`	`string`	`.cache`	file extension for your cache files
`googleCache`	`boolean`	`true`	using google cache proxy

isCached()

Check is your image already cached or not. this function need 2 params.

imageCache.isCached(url, callback);

Params

Key	Data Type
`url`	`string`
`callback`	`function`

Example

imageCache.isCached(url, function(exist) {
   if (exist) {
      // do something with cached image
   }
});

isCachedSync()

Check is your image is cached with Synchronous processing. return as boolean

Example

var exists = imageCache.isCachedSync(url);

API

Params	Data Type	Description
`url`	`string`	url of your image

getCache()

Get Cached Image

Example

imageCache.getCache(url, function(error, image) {
   console.log(image);

   // do something with image
});

API Callback

Key	Data Type	Description
`image`	`object`	cache data object
`image.error`	`boolean`	cache data error indicator
`image.url`	`string`	image source url before transform to base64 format
`image.hashFile`	`string`	filename cache
`image.timestamp`	`integer`	timestamp when cache created
`image.compressed`	`boolean`	is that cache compressed
`image.data`	`string`	base64 code, ugly text from your beauty images

getCacheSync

Get Cached image with Synchronous processing.

Example

var image = imageCache.getCache('http://domain/path/to/image.png');

API

API return same like .getCache()

setCache()

Set new Cache, write cache files into options.dir Directory. set cache is working with multiple images.

imageCache.setCache(images, callback);

Params

Key	Data Type
`images`	`array`	`string`
`callback`	`function`

Example

let images = 'https://eladnava.com/content/images/2015/11/js-6.jpg';
imageCache.setCache(images, function(error) {
   console.log(error);
});

API Callback

Key	Data Type	Description
`error`	`object`	this error came from `fs.writeFile`

flushCache()

Delete all cache files on your directory. this code will delete all cache on options.dir with extension name same as options.extname.

Example

imageCache.flushCache(function(error, results) {
   if (error) {
      console.log(error);
   } else {
      console.log(results);
   }
});

API Callback

Key	Data Type	Description
`results`	`object`	details
`results.deleted`	`number`	total of deleted files
`results.totalFiles`	`number`	total files on directory
`results.dir`	`string`	Directory cache images

flushCacheSync()

same like flushCache, but using Synchronous processing.

Example

var results = imageCache.flushCache();

API

same like flushCache()

Key	Data Type	Description
`results.error`	`boolean`	error statement
`results.message`	`string`	error message

fetchImage()

fetchImage is a function to store cache and get cache data in one time. fetchImage using Async processing for best performace. fetchImage() check your cache file first, if your image is not available in cache folder then this function will get image and return your cache data.

fetchImage() using Promise. fetchImage callback is return as Array.

Params

Key	Data Type	Description
`image`	`string` or `array`	image or array of images

Example

var image = "http://path.to/image.jpg";

imageCache.fetchImage(image).then((images) => {
   images.forEach((image) => {
      console.log(image);

      // { ... }
   });
   console.log(images);

   // [ { ... } ]
});

API

Key	Data Type	Description
`images`	`array`	cache data array group
`image`	`object`	cache data object
`image.error`	`boolean`	cache data error indicator
`image.url`	`string`	image source url before transform to base64 format
`image.hashFile`	`string`	filename cache
`image.timestamp`	`integer`	timestamp when cache created
`image.compressed`	`boolean`	is that cache compressed
`image.data`	`string`	base64 code, ugly text from your beauty images
`image.cache`	`string`	cache status is "MISS" or "HIT"