https://github.com/ptarjan/node-cache

A simple in-memory cache for nodejs
https://github.com/ptarjan/node-cache

Last synced: about 2 months ago
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A simple in-memory cache for nodejs

• Host: GitHub
• URL: https://github.com/ptarjan/node-cache
• Owner: ptarjan
• License: bsd-2-clause
• Created: 2010-04-29T20:52:49.000Z (over 14 years ago)
• Default Branch: master
• Last Pushed: 2020-12-08T22:19:00.000Z (almost 4 years ago)
• Last Synced: 2024-01-31T05:59:08.232Z (8 months ago)
• Language: JavaScript
• Homepage:
• Size: 74.2 KB
• Stars: 1,566
• Watchers: 26
• Forks: 214
• Open Issues: 32
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# memory-cache [![Build Status](https://travis-ci.org/ptarjan/node-cache.svg?branch=master)](https://travis-ci.org/ptarjan/node-cache)

A simple in-memory cache for node.js

## Installation

    npm install memory-cache --save

## Usage

```javascript

var cache = require('memory-cache');

// now just use the cache

cache.put('foo', 'bar');

console.log(cache.get('foo'));

// that wasn't too interesting, here's the good part

cache.put('houdini', 'disappear', 100, function(key, value) {

    console.log(key + ' did ' + value);

}); // Time in ms

console.log('Houdini will now ' + cache.get('houdini'));

setTimeout(function() {

    console.log('Houdini is ' + cache.get('houdini'));

}, 200);

// create new cache instance

var newCache = new cache.Cache();

newCache.put('foo', 'newbaz');

setTimeout(function() {

  console.log('foo in old cache is ' + cache.get('foo'));

  console.log('foo in new cache is ' + newCache.get('foo'));

}, 200);

```

which should print

    bar

    Houdini will now disappear

    houdini did disappear

    Houdini is null

    foo in old cache is baz

    foo in new cache is newbaz

## API

### put = function(key, value, time, timeoutCallback)

* Simply stores a value

* If time isn't passed in, it is stored forever

* Will actually remove the value in the specified time in ms (via `setTimeout`)

* timeoutCallback is optional function fired after entry has expired with key and value passed (`function(key, value) {}`)

* Returns the cached value

### get = function(key)

* Retrieves a value for a given key

* If value isn't cached, returns `null`

### del = function(key)

* Deletes a key, returns a boolean specifying whether or not the key was deleted

### clear = function()

* Deletes all keys

### size = function()

* Returns the current number of entries in the cache

### memsize = function()

* Returns the number of entries taking up space in the cache

* Will usually `== size()` unless a `setTimeout` removal went wrong

### debug = function(bool)

* Turns on or off debugging

### hits = function()

* Returns the number of cache hits (only monitored in debug mode)

### misses = function()

* Returns the number of cache misses (only monitored in debug mode)

### keys = function()

* Returns all the cache keys

### exportJson = function()

* Returns a JSON string representing all the cache data

* Any timeoutCallbacks will be ignored

### importJson = function(json: string, options: { skipDuplicates: boolean })

* Merges all the data from a previous call to `export` into the cache

* Any existing entries before an `import` will remain in the cache

* Any duplicate keys will be overwritten, unless `skipDuplicates` is `true`

* Any entries that would have expired since being exported will expire upon being imported (but their callbacks will not be invoked)

* Available `options`:

  * `skipDuplicates`: If `true`, any duplicate keys will be ignored when importing them. Defaults to `false`.

* Returns the new size of the cache

### Cache = function()

* Cache constructor

* note that `require('cache')` would return the default instance of Cache

* while `require('cache').Cache` is the actual class

## Note on Patches/Pull Requests

* Fork the project.

* Make your feature addition or bug fix.

* Send me a pull request.