com.elasticpath.xpf.connectivity.cache.impl

Class XPFSynchronizedCacheSupportImpl<K,V>

java.lang.Object

com.elasticpath.xpf.connectivity.cache.impl.XPFSynchronizedCacheSupportImpl<K,V>

Type Parameters:

K - the cache key type

V - the result type

All Implemented Interfaces:

XPFSynchronizedCacheSupport<K,V>

public class XPFSynchronizedCacheSupportImpl<K,V>
extends Object
implements XPFSynchronizedCacheSupport<K,V>

A support class for managing interactions with a SimpleTimeoutCache backed by EhCache. This implementation provides the following guarantees:

1. Threads will only be blocked if there is a cache miss and there is already an evaluation running for an equivalent cache key. Lookups for different cache keys will not be blocked.

2. Only one evaluation will be executed for a cache miss of a given cache key.

3. While a cache miss evaluation is in progress, requests from separate threads for the same cache key will block until evaluation is complete and they will get the cached value after the evaluation completes.

tldr: This class virtually eliminates unnecessary cache miss evaluations and blocks threads only when a cache miss occurs for an equivalent cache key.

Constructor Summary

Constructors

Constructor and Description
XPFSynchronizedCacheSupportImpl()

Method Summary

Modifier and Type	Method and Description
V	get(K cacheKey, Function<K,V> fallbackLoaderFunction, Function<K,XPFCacheResult<V>> checkCacheFunction, BiFunction<K,V,V> populateCacheFunction) Get the requested key from the cache, or use the fallback loader function if the key is not present.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XPFSynchronizedCacheSupportImpl

public XPFSynchronizedCacheSupportImpl()

Method Detail

get

public V get(K cacheKey,
             Function<K,V> fallbackLoaderFunction,
             Function<K,XPFCacheResult<V>> checkCacheFunction,
             BiFunction<K,V,V> populateCacheFunction)

Description copied from interface: XPFSynchronizedCacheSupport

Get the requested key from the cache, or use the fallback loader function if the key is not present. In the case of a miss, this method will cache the result of the fallback loader execution, ensuring that the cache population function is only invoked once per cache miss for a particular cache key.

Specified by:

get in interface XPFSynchronizedCacheSupport<K,V>

Parameters:

cacheKey - the cache key object

fallbackLoaderFunction - the function for populating the cache

checkCacheFunction - the function for retrieving the passed key from the cache

populateCacheFunction - the function for populating the cache with the passed key and value

Returns:

the result