Package 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 @NullMarked 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
    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.
    @Nullable CompletableFuture<V>
    get(K key)
    Gets the specified key from the cache map.
    Collection<CompletableFuture<V>>
    getAll()
    Gets a collection of CompletableFutures from the cache map.
    CacheMap<K,V>
    set(K key, 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 Details

    • 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

      @Nullable CompletableFuture<V> get(K key)
      Gets the specified key from the cache map.

      May throw an exception if the key does not exist, depending on the cache map implementation that is used.

      Parameters:
      key - the key to retrieve
      Returns:
      the cached value, or null if not found (depends on cache implementation)

    • getAll

      Collection<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, 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