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

• Compressed options default is false
• Library Core now using Javascript Classes
• New syntax and function
• 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

const 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	false	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 Using Callback

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

Example Using Promise

imageCache.isCached(url).then((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

Deprecated

get()

Get cached image

Example

imageCache.get(url, (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

Deprecated

getSync

Get Cached image with Synchronous processing.

Example

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

API

API return same like .get()

setCache()

Deprecated

store()

store new image want to cache, write cache files into options.dir Directory. set cache is working with multiple images (Array).

imageCache.store(images, callback);

Params

Key	Data Type
images	array
callback	function

Example Using Callback

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

Example Using Promise

let images = 'https://eladnava.com/content/images/2015/11/js-6.jpg';
imageCache.store(images).then((result) {
    // do something when image stored
}).catch((e) => {
    console.log(e)
});

API Callback and Promise Catch

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

flushCache()

Deprecated

flush()

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

Example Using Callback

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

Example Using Promise

imageCache.flush().then((results) => {
    console.log(results);
}).then((error) => {
    console.log(error);
});

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

flushSync()

same like flush method, but using Synchronous processing.

Example

var results = imageCache.flushSync();

API

same like flush()

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

fetchImage()

Deprecated

fetch()

fetch() is a function to store cache and get cache data in one time. fetch() using Async processing for best performace. fetch() 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.

Params

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

Example

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

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

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

   // [ { ... } ]
}).catch((error) => {

});

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"

What is MISS or HIT mean?

MISS

when your image is not available in the cache folder, image will be grab from image URL then cached on cache folder.

HIT

when your image is available in the cache folder, the image will be grab directly from cache folder.