Caffeine cache 3.1.8 · com.github.benmanes.caffeine.cache.CacheLoader

Method Summary

Modifier and Type	Method and Description
public default CompletableFuture<? extends V>	Returns: the future value associated with `key` asyncLoad(K the non-null key whose value should be loaded key, Executor the executor that asynchronously loads the entry executor) Implements com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoad. Asynchronously computes or retrieves the value corresponding to `key`.
public default CompletableFuture<? extends Map<? extends K, ? extends V>>	Returns: a future containing the map from each key in `keys` to the value associated with that key; may not contain null values asyncLoadAll(Set<? extends K> the unique, non-null keys whose values should be loaded keys, Executor the executor that with asynchronously loads the entries executor) Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoadAll. Asynchronously computes or retrieves the values corresponding to `keys`.
public default CompletableFuture<? extends V>	Returns: a future containing the new value associated with `key`, or containing `null` if the mapping is to be removed asyncReload(K the non-null key whose value should be loaded key, V the non-null old value corresponding to `key` oldValue, Executor the executor with which the entry is asynchronously loaded executor) Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncReload. Asynchronously computes or retrieves a replacement value corresponding to an already-cached `key`.
public static < the key type K, the value type V> CacheLoader<K, V>	Returns: a cache loader that delegates to the supplied `mappingFunction` bulk(Function<? super Set<? extends K>, ? extends Map<? extends K, ? extends V>> the function to compute the values mappingFunction) Hides com.github.benmanes.caffeine.cache.AsyncCacheLoader.bulk. Returns a cache loader that delegates to the supplied mapping function for retrieving the values.
public @Nullable V	Returns: the value associated with `key` or `null` if not found load(K the non-null key whose value should be loaded key) Computes or retrieves the value corresponding to `key`.
public default Map<? extends K, ? extends V>	Returns: a map from each key in `keys` to the value associated with that key; may not contain null values loadAll(Set<? extends K> the unique, non-null keys whose values should be loaded keys) Computes or retrieves the values corresponding to `keys`.
public default @Nullable V	Returns: the new value associated with `key`, or `null` if the mapping is to be removed reload(K the non-null key whose value should be loaded key, V the non-null old value corresponding to `key` oldValue) Computes or retrieves a replacement value corresponding to an already-cached `key`.

Inherited from com.github.benmanes.caffeine.cache.AsyncCacheLoader:: bulk

Method Detail

asyncLoad back to summary

asyncLoad	back to summary
public default CompletableFuture<? extends V> asyncLoad(K key, Executor executor) throws Exception Implements com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoad. Asynchronously computes or retrieves the value corresponding to `key`. Parameters key:K the non-null key whose value should be loaded executor:Executor the executor that asynchronously loads the entry Returns:CompletableFuture<? extends V> the future value associated with `key` Annotations @Override Exceptions Exception: Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoad. or Error, in which case the mapping is unchanged

public default CompletableFuture<? extends V> asyncLoad(K key, Executor executor) throws Exception

Implements com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoad.

Asynchronously computes or retrieves the value corresponding to key.

Parameters

key:K: the non-null key whose value should be loaded
executor:Executor: the executor that asynchronously loads the entry

Returns:CompletableFuture<? extends V>

the future value associated with key

Annotations

@Override

Exceptions

Exception:

Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoad.

or Error, in which case the mapping is unchanged

asyncLoadAll back to summary

asyncLoadAll	back to summary
public default CompletableFuture<? extends Map<? extends K, ? extends V>> asyncLoadAll(Set<? extends K> keys, Executor executor) throws Exception Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoadAll. Asynchronously computes or retrieves the values corresponding to `keys`. This method is called by `AsyncLoadingCache#getAll`. If the returned map doesn't contain all requested `keys`, then the entries it does contain will be cached, and `getAll` will return the partial results. If the returned map contains extra keys not present in `keys` then all returned entries will be cached, but only the entries for `keys`, will be returned from `getAll`. This method should be overridden when bulk retrieval is significantly more efficient than many individual lookups. Note that `AsyncLoadingCache#getAll` will defer to individual calls to `AsyncLoadingCache#get` if this method is not overridden. Warning loading must not attempt to update any mappings of this cache directly. Parameters keys:Set<? extends K> the unique, non-null keys whose values should be loaded executor:Executor the executor that with asynchronously loads the entries Returns:CompletableFuture<? extends Map<? extends K, ? extends V>> a future containing the map from each key in `keys` to the value associated with that key; may not contain null values Annotations @Override Exceptions Exception: Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoadAll. or Error, in which case the mappings are unchanged

public default CompletableFuture<? extends Map<? extends K, ? extends V>> asyncLoadAll(Set<? extends K> keys, Executor executor) throws Exception

Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoadAll.

Asynchronously computes or retrieves the values corresponding to keys. This method is called by AsyncLoadingCache#getAll.

If the returned map doesn't contain all requested keys, then the entries it does contain will be cached, and getAll will return the partial results. If the returned map contains extra keys not present in keys then all returned entries will be cached, but only the entries for keys, will be returned from getAll.

This method should be overridden when bulk retrieval is significantly more efficient than many individual lookups. Note that AsyncLoadingCache#getAll will defer to individual calls to AsyncLoadingCache#get if this method is not overridden.

Warning

loading must not attempt to update any mappings of this cache directly.

Parameters

keys:Set<? extends K>: the unique, non-null keys whose values should be loaded
executor:Executor: the executor that with asynchronously loads the entries

Returns:CompletableFuture<? extends Map<? extends K, ? extends V>>

a future containing the map from each key in keys to the value associated with that key; may not contain null values

Annotations

@Override

Exceptions

Exception:

Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncLoadAll.

or Error, in which case the mappings are unchanged

asyncReload back to summary

asyncReload	back to summary
public default CompletableFuture<? extends V> asyncReload(K key, V oldValue, Executor executor) throws Exception Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncReload. Asynchronously computes or retrieves a replacement value corresponding to an already-cached `key`. If the replacement value is not found then the mapping will be removed if `null` is computed. This method is called when an existing cache entry is refreshed by `Caffeine#refreshAfterWrite`, or through a call to `LoadingCache#refresh`. Warning loading must not attempt to update any mappings of this cache directly or block waiting for other cache operations to complete. Note all exceptions thrown by this method will be logged and then swallowed. Parameters key:K the non-null key whose value should be loaded oldValue:V the non-null old value corresponding to `key` executor:Executor the executor with which the entry is asynchronously loaded Returns:CompletableFuture<? extends V> a future containing the new value associated with `key`, or containing `null` if the mapping is to be removed Annotations @Override Exceptions Exception: Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncReload. or Error, in which case the mapping is unchanged

public default CompletableFuture<? extends V> asyncReload(K key, V oldValue, Executor executor) throws Exception

Overrides default com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncReload.

Asynchronously computes or retrieves a replacement value corresponding to an already-cached key. If the replacement value is not found then the mapping will be removed if null is computed. This method is called when an existing cache entry is refreshed by Caffeine#refreshAfterWrite, or through a call to LoadingCache#refresh.

Warning

loading must not attempt to update any mappings of this cache directly or block waiting for other cache operations to complete.

Note

all exceptions thrown by this method will be logged and then swallowed.

Parameters

key:K: the non-null key whose value should be loaded
oldValue:V: the non-null old value corresponding to key
executor:Executor: the executor with which the entry is asynchronously loaded

Returns:CompletableFuture<? extends V>

a future containing the new value associated with key, or containing null if the mapping is to be removed

Annotations

@Override

Exceptions

Exception:

Doc from com.github.benmanes.caffeine.cache.AsyncCacheLoader.asyncReload.

or Error, in which case the mapping is unchanged

bulk back to summary

bulk	back to summary
public static <K, V> CacheLoader<K, V> bulk(Function<? super Set<? extends K>, ? extends Map<? extends K, ? extends V>> mappingFunction) Hides com.github.benmanes.caffeine.cache.AsyncCacheLoader.bulk. Returns a cache loader that delegates to the supplied mapping function for retrieving the values. Note that `load` will silently discard any additional mappings loaded when retrieving the `key` prior to returning to the value to the cache. Usage example: `CacheLoader<Key, Graph> loader = CacheLoader.bulk(keys -> createExpensiveGraphs(keys)); LoadingCache<Key, Graph> cache = Caffeine.newBuilder().build(loader);` Parameters <K> the key type <V> the value type mappingFunction:Function<? super Set<? extends K>, ? extends Map<? extends K, ? extends V>> the function to compute the values Returns:CacheLoader<K, V> a cache loader that delegates to the supplied `mappingFunction` Annotations @SuppressWarnings:FunctionalInterfaceClash Exceptions NullPointerException: if the mappingFunction is null

public static <K, V> CacheLoader<K, V> bulk(Function<? super Set<? extends K>, ? extends Map<? extends K, ? extends V>> mappingFunction)

Hides com.github.benmanes.caffeine.cache.AsyncCacheLoader.bulk.

Returns a cache loader that delegates to the supplied mapping function for retrieving the values. Note that load will silently discard any additional mappings loaded when retrieving the key prior to returning to the value to the cache.

Usage example:

CacheLoader<Key, Graph> loader = CacheLoader.bulk(keys -> createExpensiveGraphs(keys));
  LoadingCache<Key, Graph> cache = Caffeine.newBuilder().build(loader);

Parameters

<K>: the key type
<V>: the value type
mappingFunction:Function<? super Set<? extends K>, ? extends Map<? extends K, ? extends V>>: the function to compute the values

Returns:CacheLoader<K, V>

a cache loader that delegates to the supplied mappingFunction

Annotations

@SuppressWarnings:FunctionalInterfaceClash

Exceptions

NullPointerException:: if the mappingFunction is null

load back to summary

load	back to summary
public @Nullable V load(K key) throws Exception Computes or retrieves the value corresponding to `key`. Warning loading must not attempt to update any mappings of this cache directly. Parameters key:K the non-null key whose value should be loaded Returns:@Nullable V the value associated with `key` or `null` if not found Exceptions Exception: or Error, in which case the mapping is unchanged InterruptedException: if this method is interrupted. `InterruptedException` is treated like any other `Exception` in all respects except that, when it is caught, the thread's interrupt status is set

public @Nullable V load(K key) throws Exception

Computes or retrieves the value corresponding to key.

Warning

loading must not attempt to update any mappings of this cache directly.

Parameters

key:K: the non-null key whose value should be loaded

Returns:@Nullable V

the value associated with key or null if not found

Exceptions

Exception:: or Error, in which case the mapping is unchanged
InterruptedException:: if this method is interrupted. InterruptedException is treated like any other Exception in all respects except that, when it is caught, the thread's interrupt status is set

loadAll back to summary

loadAll	back to summary
public default Map<? extends K, ? extends V> loadAll(Set<? extends K> keys) throws Exception Computes or retrieves the values corresponding to `keys`. This method is called by `LoadingCache#getAll`. If the returned map doesn't contain all requested `keys`, then the entries it does contain will be cached, and `getAll` will return the partial results. If the returned map contains extra keys not present in `keys` then all returned entries will be cached, but only the entries for `keys`, will be returned from `getAll`. This method should be overridden when bulk retrieval is significantly more efficient than many individual lookups. Note that `LoadingCache#getAll` will defer to individual calls to `LoadingCache#get` if this method is not overridden. Warning loading must not attempt to update any mappings of this cache directly. Parameters keys:Set<? extends K> the unique, non-null keys whose values should be loaded Returns:Map<? extends K, ? extends V> a map from each key in `keys` to the value associated with that key; may not contain null values Exceptions Exception: or Error, in which case the mappings are unchanged InterruptedException: if this method is interrupted. `InterruptedException` is treated like any other `Exception` in all respects except that, when it is caught, the thread's interrupt status is set

public default Map<? extends K, ? extends V> loadAll(Set<? extends K> keys) throws Exception

Computes or retrieves the values corresponding to keys. This method is called by LoadingCache#getAll.

This method should be overridden when bulk retrieval is significantly more efficient than many individual lookups. Note that LoadingCache#getAll will defer to individual calls to LoadingCache#get if this method is not overridden.

Warning

loading must not attempt to update any mappings of this cache directly.

Parameters

keys:Set<? extends K>: the unique, non-null keys whose values should be loaded

Returns:Map<? extends K, ? extends V>

a map from each key in keys to the value associated with that key; may not contain null values

Exceptions

Exception:: or Error, in which case the mappings are unchanged
InterruptedException:: if this method is interrupted. InterruptedException is treated like any other Exception in all respects except that, when it is caught, the thread's interrupt status is set

reload back to summary

reload	back to summary
public default @Nullable V reload(K key, V oldValue) throws Exception Computes or retrieves a replacement value corresponding to an already-cached `key`. If the replacement value is not found, then the mapping will be removed if `null` is returned. This method is called when an existing cache entry is refreshed by `Caffeine#refreshAfterWrite`, or through a call to `LoadingCache#refresh`. Warning loading must not attempt to update any mappings of this cache directly or block waiting for other cache operations to complete. Note all exceptions thrown by this method will be logged and then swallowed. Parameters key:K the non-null key whose value should be loaded oldValue:V the non-null old value corresponding to `key` Returns:@Nullable V the new value associated with `key`, or `null` if the mapping is to be removed Exceptions Exception: or Error, in which case the mapping is unchanged InterruptedException: if this method is interrupted. `InterruptedException` is treated like any other `Exception` in all respects except that, when it is caught, the thread's interrupt status is set

public default @Nullable V reload(K key, V oldValue) throws Exception

Computes or retrieves a replacement value corresponding to an already-cached key. If the replacement value is not found, then the mapping will be removed if null is returned. This method is called when an existing cache entry is refreshed by Caffeine#refreshAfterWrite, or through a call to LoadingCache#refresh.

Warning

loading must not attempt to update any mappings of this cache directly or block waiting for other cache operations to complete.

Note

all exceptions thrown by this method will be logged and then swallowed.

Parameters

key:K: the non-null key whose value should be loaded
oldValue:V: the non-null old value corresponding to key

Returns:@Nullable V

the new value associated with key, or null if the mapping is to be removed

Exceptions

Exception:: or Error, in which case the mapping is unchanged
InterruptedException:: if this method is interrupted. InterruptedException is treated like any other Exception in all respects except that, when it is caught, the thread's interrupt status is set

public Interface CacheLoader<K, V>

Method Summary

Method Detail