Package org.apache.maven.impl.cache

Interface Cache<K,V>

Type Parameters:

K - the type of keys maintained by this cache

V - the type of cached values

All Known Implementing Classes:

Cache.RefConcurrentMap

public interface Cache<K,V>

A cache interface that provides configurable reference types for both keys and values, and supports automatic cleanup of garbage-collected entries.

This cache is designed for scenarios where:

• Values should be eligible for garbage collection when memory is low
• Concurrent access is required
• Automatic cleanup of stale entries is desired

The cache can use different reference types (none, soft, weak, hard) for both keys and values, depending on the factory method used to create the cache instance.

Note: All implementations are thread-safe and optimized for concurrent read access.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	Cache.EvictionListener	Interface for listening to cache eviction events.
static class	Cache.RefConcurrentMap<K,V>	A concurrent map implementation that uses configurable reference types for both keys and values, and supports automatic cleanup of garbage-collected entries.
static enum	Cache.ReferenceType	Enumeration of reference types that can be used for individual entries.

Method Summary

Modifier and Type	Method	Description
void	clear()
default V	computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction)
V	computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction, Cache.ReferenceType referenceType)	Computes a value for the given key if it's not already present, using the specified reference type.
default boolean	containsKey(K key)
V	get(K key)
static <K, V> Cache<K,V>	newCache(Cache.ReferenceType referenceType)
static <K, V> Cache<K,V>	newCache(Cache.ReferenceType referenceType, String name)
static <K, V> Cache<K,V>	newCache(Cache.ReferenceType keyReferenceType, Cache.ReferenceType valueReferenceType)	Creates a new cache with separate reference types for keys and values.
static <K, V> Cache<K,V>	newCache(Cache.ReferenceType keyReferenceType, Cache.ReferenceType valueReferenceType, String name)
void	removeIf(BiPredicate<K,V> o)
int	size()

Method Details

computeIfAbsent

V computeIfAbsent(K key,
 Function<? super K,? extends V> mappingFunction,
 Cache.ReferenceType referenceType)

Computes a value for the given key if it's not already present, using the specified reference type.

This method allows fine-grained control over the reference type used for individual entries, overriding the cache's default reference type for this specific key-value pair.

Parameters:

key - the key whose associated value is to be returned or computed

mappingFunction - the function to compute a value

referenceType - the reference type to use for this entry (null uses cache default)

Returns:

the current (existing or computed) value associated with the specified key

computeIfAbsent

default V computeIfAbsent(K key,
 Function<? super K,? extends V> mappingFunction)

removeIf

void removeIf(BiPredicate<K,V> o)

get

V get(K key)

size

int size()

clear

void clear()

containsKey

default boolean containsKey(K key)

newCache

static <K,
V> Cache<K,V> newCache(Cache.ReferenceType referenceType)

newCache

static <K,
V> Cache<K,V> newCache(Cache.ReferenceType referenceType,
 String name)

newCache

static <K,
V> Cache<K,V> newCache(Cache.ReferenceType keyReferenceType,
 Cache.ReferenceType valueReferenceType)

Creates a new cache with separate reference types for keys and values. This allows fine-grained control over eviction behavior and enables better tracking of cache misses caused by key vs value evictions.

Parameters:

keyReferenceType - the reference type to use for keys

valueReferenceType - the reference type to use for values

Returns:

a new cache instance

newCache

static <K,
V> Cache<K,V> newCache(Cache.ReferenceType keyReferenceType,
 Cache.ReferenceType valueReferenceType,
 String name)