org.infinispan.commons.api.functional

Interface FunctionalMap.ReadWriteMap<K,V>

All Superinterfaces:

AutoCloseable, FunctionalMap<K,V>

Enclosing interface:

FunctionalMap<K,V>

public static interface FunctionalMap.ReadWriteMap<K,V>
extends FunctionalMap<K,V>

Exposes read-write operations that can be executed against the functional map. The read-write operations that can be applied per entry are exposed by EntryView.ReadWriteEntryView.

Read-write operations offer the possibility of writing values or metadata parameters, and returning previously stored information. Read-write operations are also crucial for implementing conditional, compare-and-swap (CAS) like operations.

Locks are acquired before executing the read-write lambda.

Method parameters for read-write operations, including lambdas, must be marshallable when running in a cluster.

Since:

8.0

Nested Class Summary

Nested classes/interfaces inherited from interface org.infinispan.commons.api.functional.FunctionalMap

FunctionalMap.ReadOnlyMap<K,V>, FunctionalMap.ReadWriteMap<K,V>, FunctionalMap.WriteOnlyMap<K,V>

Method Summary

Modifier and Type	Method and Description
<R> CompletableFuture<R>	eval(K key, Function<EntryView.ReadWriteEntryView<K,V>,R> f) Evaluate a read-write function on the value and metadata associated with the key and return a CompletableFuture with the return type of the function.
<R> CompletableFuture<R>	eval(K key, V value, BiFunction<V,EntryView.ReadWriteEntryView<K,V>,R> f) Evaluate a read-write function, with a value passed in and a EntryView.WriteEntryView of the value associated with the key, and return a CompletableFuture which will be completed with the returned value by the function.
<R> Traversable<R>	evalAll(Function<EntryView.ReadWriteEntryView<K,V>,R> f) Evaluate a read-write Function operation with the EntryView.ReadWriteEntryView of the value associated with the key, for all existing keys, and returns a Traversable to navigate each of the Function invocation returns.
<R> Traversable<R>	evalMany(Map<? extends K,? extends V> entries, BiFunction<V,EntryView.ReadWriteEntryView<K,V>,R> f) Evaluate a read-write BiFunction, with a value passed in and a EntryView.ReadWriteEntryView of the value associated with the key, for each of the keys in the set passed in, and returns an Traversable to navigate each of the BiFunction invocation returns.
<R> Traversable<R>	evalMany(Set<? extends K> keys, Function<EntryView.ReadWriteEntryView<K,V>,R> f) Evaluate a read-write Function operation with the EntryView.ReadWriteEntryView of the value associated with the key, for each of the keys in the set passed in, and returns a Traversable to navigate each of the Function invocation returns.
Listeners.ReadWriteListeners<K,V>	listeners() Allows to read-write listeners to be registered.
FunctionalMap.ReadWriteMap<K,V>	withParams(Param<?>... ps) Tweak read-write functional map executions providing Param instances.

Methods inherited from interface org.infinispan.commons.api.functional.FunctionalMap

getName, getStatus

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

withParams

FunctionalMap.ReadWriteMap<K,V> withParams(Param<?>... ps)

Tweak read-write functional map executions providing Param instances.

Specified by:

withParams in interface FunctionalMap<K,V>

eval

<R> CompletableFuture<R> eval(K key,
                              Function<EntryView.ReadWriteEntryView<K,V>,R> f)

Evaluate a read-write function on the value and metadata associated with the key and return a CompletableFuture with the return type of the function. If the user is not sure if the key is present, EntryView.ReadEntryView.find() can be used to find out for sure. This method can be used to implement single-key read-write operations in ConcurrentMap and javax.cache.Cache that do not depend on value information given by the user such as:

• Map.remove(Object)
• javax.cache.Cache#remove(Object)
• javax.cache.Cache#getAndRemove(Object)
• javax.cache.Cache#invoke(Object, EntryProcessor, Object...)

Type Parameters:

R - function return type

Parameters:

key - the key associated with the EntryView.ReadWriteEntryView to be passed to the function.

f - function that takes a EntryView.ReadWriteEntryView associated with the key, and returns a value.

Returns:

a CompletableFuture which will be completed with the returned value from the function

eval

<R> CompletableFuture<R> eval(K key,
                              V value,
                              BiFunction<V,EntryView.ReadWriteEntryView<K,V>,R> f)

Evaluate a read-write function, with a value passed in and a EntryView.WriteEntryView of the value associated with the key, and return a CompletableFuture which will be completed with the returned value by the function.

This method provides the the capability to both update the value and metadata associated with that key, and return previous value or metadata.

This method can be used to implement the vast majority of single-key read-write operations in ConcurrentMap and javax.cache.Cache such as:

• Map.put(Object, Object)
• ConcurrentMap.putIfAbsent(Object, Object)
• ConcurrentMap.replace(Object, Object)
• ConcurrentMap.replace(Object, Object, Object)
• ConcurrentMap.remove(Object, Object)
• javax.cache.Cache#getAndPut(Object, Object)
• javax.cache.Cache#putIfAbsent(Object, Object)
• javax.cache.Cache#remove(Object, Object)
• javax.cache.Cache#replace(Object, Object, Object)
• javax.cache.Cache#replace(Object, Object)
• javax.cache.Cache#getAndReplace(Object, Object)

The functionality provided by this function could indeed be implemented with eval(Object, Function), but there's a crucial difference. If you want to store a value and reference the value to be stored from the passed in operation, eval(Object, Function) needs to capture that value. Capturing means that each time the operation is called, a new lambda needs to be instantiated. By offering a BiFunction that takes user provided value as first parameter, the operation does not capture any external objects when implementing simple operations such as javax.cache.Cache#getAndPut(Object, Object), and hence, the BiFunction could be cached and reused each time it's invoked.

Type Parameters:

R - type of the function's return

Parameters:

key - the key associated with the EntryView.ReadWriteEntryView to be passed to the operation

value - value to write, passed in as first parameter to the BiFunction.

f - operation that takes a user defined value, and a EntryView.ReadWriteEntryView associated with the key, and writes to the EntryView.ReadWriteEntryView passed in, possibly returning previously stored value or metadata information

Returns:

a CompletableFuture which will be completed with the returned value from the function

evalMany

<R> Traversable<R> evalMany(Map<? extends K,? extends V> entries,
                            BiFunction<V,EntryView.ReadWriteEntryView<K,V>,R> f)

Evaluate a read-write BiFunction, with a value passed in and a EntryView.ReadWriteEntryView of the value associated with the key, for each of the keys in the set passed in, and returns an Traversable to navigate each of the BiFunction invocation returns.

This method can be used to implement operations that store a set of keys and return previous values or metadata parameters.

These kind of operations are preferred to traditional end user iterations because the internal logic can often iterate more efficiently since it knows more about the system.

Parameters:

entries - the key/value pairs associated with each of the EntryView.ReadWriteEntryView passed in the function callbacks

f - function that takes in a value associated with a key in the entries collection and the EntryView.ReadWriteEntryView associated with that key in the cache

Returns:

a Traversable to navigate each BiFunction return

evalMany

<R> Traversable<R> evalMany(Set<? extends K> keys,
                            Function<EntryView.ReadWriteEntryView<K,V>,R> f)

Evaluate a read-write Function operation with the EntryView.ReadWriteEntryView of the value associated with the key, for each of the keys in the set passed in, and returns a Traversable to navigate each of the Function invocation returns.

This method can be used to implement operations such as javax.cache.Cache#invokeAll(Set, EntryProcessor, Object...), or a remove a set of keys returning previous values or metadata parameters.

Parameters:

keys - the keys associated with each of the EntryView.ReadWriteEntryView passed in the function callbacks

f - function that the EntryView.ReadWriteEntryView associated with one of the keys passed in, and returns a value

Returns:

a Traversable to navigate each Function return

evalAll

<R> Traversable<R> evalAll(Function<EntryView.ReadWriteEntryView<K,V>,R> f)

Evaluate a read-write Function operation with the EntryView.ReadWriteEntryView of the value associated with the key, for all existing keys, and returns a Traversable to navigate each of the Function invocation returns.

This method can be used to an operation that removes all cached entries individually, and returns previous value and/or metadata parameters.

Returns:

a Traversable to navigate each Function return

listeners

Listeners.ReadWriteListeners<K,V> listeners()

Allows to read-write listeners to be registered.