Simple and fast NodeJS internal caching.

A simple caching module that has set, get and delete methods and works a little bit like memcached. Keys can have a timeout after which they expire and are cleaned from the cache.
All keys are stored in a single object so the practical limit is at around 1m keys.

Written in coffee-script

Install

  npm install node-cache

Or just require the node_cache.js file to get the superclass

Examples:

Initialize:

var NodeCache = require( "node-cache" );
var myCache = new NodeCache();

Store a key (SET):

myCache.set( key, val, [ ttl ], callback )

Sets a key value pair. It is possible to define a ttl (in seconds).
Returns true on success.

obj = { my: "Special", variable: 42 };
myCache.set( "myKey", obj, function( err, success ){
  if( !err && success ){
    console.log( success );
    // true
    // ... do something ...
  }
});

Retrieve a key (GET):

myCache.get( key, callback )

Gets a saved value from the cache. Returns an empty object {} if not found or expired. If the value was found it returns an object with the key value pair.

myCache.get( "myKey", function( err, value ){
  if( !err ){
    console.log( value );
    // { "myKey": { my: "Special", variable: 42 } }
    // ... do something ...
  }
});

Retrieve multiple keys (GET):

myCache.get( [ key1, key2, ... ,keyn ], callback )

Gets multiple saved values from the cache. Returns an empty object {} if not found or expired. If the value was found it returns an object with the key value pair.

myCache.get( [ "myKeyA", "myKeyB" ], function( err, value ){
  if( !err ){
    console.log( value );
    /*
      {
        "myKeyA": { my: "Special", variable: 123 },
        "myKeyB": { the: "Glory", answer: 42 }
      }
    */
    // ... do something ...
  }
});

Delete a key

myCache.del( key, callback )

Delete a key. Returns the number of deleted entries. A delete will never fail.

myCache.del( "myKey", function( err, count ){
  if( !err ){
    console.log( count ); // 1
    // ... do something ...
  }
});

Delete multiple keys

myCache.del( [ key1, key2, ... ,keyn ], callback )

Delete multiple keys. Returns the number of deleted entries. A delete will never fail.

myCache.del( [ "myKeyA", "myKeyB" ], function( err, count ){
  if( !err ){
    console.log( count ); // 2
    // ... do something ...
  }
});

Statistics

myCache.getStats()

Returns the statistics.

myCache.getStats();
  /*
    {
      keys: 0,    // global key count
      hits: 0,    // global hit count
      misses: 0,  // global miss count
      ksize: 0,   // global key size count
      vsize: 0    // global value size count
    }
  */

Flush all data

myCache.flushAll()

Flush all data.

myCache.flushAll();
myCache.getStats();
  /*
    {
      keys: 0,    // global key count
      hits: 0,    // global hit count
      misses: 0,  // global miss count
      ksize: 0,   // global key size count
      vsize: 0    // global value size count
    }
  */

Work in progress

nodecache is work in progress. Your ideas, suggestions etc. are very welcome.

License

(The MIT License)

Copyright (c) 2010 TCS <dev (at) tcs.de>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.