org.dataloader

Interface CacheMap<K,V>

Type Parameters:

K - type parameter indicating the type of the cache keys

V - type parameter indicating the type of the data that is cached

All Known Implementing Classes:

DefaultCacheMap

@PublicSpi
public interface CacheMap<K,V>

CacheMap is used by data loaders that use caching promises to values aka CompletableFuture<V>. A better name for this class might have been FutureCache but that is history now.

The default implementation used by the data loader is based on a LinkedHashMap.

This is really a cache of completed CompletableFuture<V> values in memory. It is used, when caching is enabled, to give back the same future to any code that may call it. If you need a cache of the underlying values that is possible external to the JVM then you will want to use {ValueCache} which is designed for external cache access.

Method Summary

Modifier and Type	Method and Description
CacheMap<K,V>	clear() Clears all entries of the cache map
boolean	containsKey(K key) Checks whether the specified key is contained in the cache map.
CacheMap<K,V>	delete(K key) Deletes the entry with the specified key from the cache map, if it exists.
java.util.concurrent.CompletableFuture<V>	get(K key) Gets the specified key from the cache map.
java.util.Collection<java.util.concurrent.CompletableFuture<V>>	getAll() Gets a collection of CompletableFutures from the cache map.
CacheMap<K,V>	set(K key, java.util.concurrent.CompletableFuture<V> value) Creates a new cache map entry with the specified key and value, or updates the value if the key already exists.
static <K,V> CacheMap<K,V>	simpleMap() Creates a new cache map, using the default implementation that is based on a LinkedHashMap.

Method Detail

simpleMap

static <K,V> CacheMap<K,V> simpleMap()

Creates a new cache map, using the default implementation that is based on a LinkedHashMap.

Type Parameters:

K - type parameter indicating the type of the cache keys

V - type parameter indicating the type of the data that is cached

Returns:

the cache map

containsKey

boolean containsKey(K key)

Checks whether the specified key is contained in the cache map.

Parameters:

key - the key to check

Returns:

true if the cache contains the key, false otherwise

get

java.util.concurrent.CompletableFuture<V> get(K key)

Gets the specified key from the cache map.

May throw an exception if the key does not exists, depending on the cache map implementation that is used, so be sure to check containsKey(Object) first.

Parameters:

key - the key to retrieve

Returns:

the cached value, or null if not found (depends on cache implementation)

getAll

java.util.Collection<java.util.concurrent.CompletableFuture<V>> getAll()

Gets a collection of CompletableFutures from the cache map.

Returns:

the collection of cached values

set

CacheMap<K,V> set(K key,
                  java.util.concurrent.CompletableFuture<V> value)

Creates a new cache map entry with the specified key and value, or updates the value if the key already exists.

Parameters:

key - the key to cache

value - the value to cache

Returns:

the cache map for fluent coding

delete

CacheMap<K,V> delete(K key)

Deletes the entry with the specified key from the cache map, if it exists.

Parameters:

key - the key to delete

Returns:

the cache map for fluent coding

clear

CacheMap<K,V> clear()

Clears all entries of the cache map

Returns:

the cache map for fluent coding