SparkCache

Provides the ability to cache javascript objects. This includes complex objects with functions. Any javascript object can be cached. This allows you to create objects of a particular structure from your JSON data in mongo that can speed up access.

This differs slighty from storing data in mongo as the data is stored in memory and expired on a LRU basis. This means access time is significantly faster for these in memory objects

Cached objects are backed by mongo for up to 30 days, so if an item is expired in memory, when you try to access it again it will be reloaded.

There is a limited amount of memory available on servers, so this should be used for few, shared configuration type objects

Using this for player data or having a large amount of objects could slow down you application as the store / reload process is more expensive than a mongo find for JSON data

Code using SparkCache should be written with the expectation that the cache may return null (if data is expired) so should be able to reconstruct and re-cache the data in this scenario.

e.g.

var theCache = Spark.getCache();

put

signature put(string key, JSON object)

returns void

Adds an object to the cache

example

theCache.put("key", myObject);

get

signature get(string key)

returns JSON

Gets an objects from the cache

returns

A JavaScipt object, or null depending on whether put has ben called for the given key

example

var myObject = theCache.get("key");

remove

signature remove(string key)

returns void

Remove an object from the cache

The object will be removed form the cache, and form the database. Subsequent calls to get will return null

example

 theCache.remove("key")

removeAll

signature removeAll()

returns void

Clears everything from the cache

example

 theCache.removeAll()

signature removeAll(string pattern)

returns void

Clears all objects from the cache where the keys match the regex pattern provided.

the match pattern is ultimately used by mongo to do a $regex query, which uses

"Perl Compatible Regular Expressions" (PCRE) as the matching engine.

 theCache.removeAll("match\..*\.2014)