Package org.springframework.util
Class ConcurrentLruCache<K,V>
java.lang.Object
org.springframework.util.ConcurrentLruCache<K,V>
- Type Parameters:
K
- the type of the key used for cache retrievalV
- the type of the cached values, does not allow null values
Simple LRU (Least Recently Used) cache, bounded by a specified cache capacity.
This is a simplified, opinionated implementation of an LRU cache for internal use in Spring Framework. It is inspired from ConcurrentLinkedHashMap.
Read and write operations are internally recorded in dedicated buffers, then drained at chosen times to avoid contention.
- Since:
- 5.3
- Author:
- Brian Clozel, Ben Manes
- See Also:
-
Constructor Summary
ConstructorDescriptionConcurrentLruCache
(int capacity, Function<K, V> generator) Create a new cache instance with the given capacity and generator function. -
Method Summary
Modifier and TypeMethodDescriptionint
capacity()
Return the maximum number of entries in the cache.void
clear()
Immediately remove all entries from this cache.boolean
Determine whether the given key is present in this cache.Retrieve an entry from the cache, potentially triggering generation of the value.boolean
Immediately remove the given key and any associated value.int
size()
Return the current size of the cache.int
Deprecated.
-
Constructor Details
-
ConcurrentLruCache
Create a new cache instance with the given capacity and generator function.- Parameters:
capacity
- the maximum number of entries in the cache (0 indicates no caching, always generating a new value)generator
- a function to generate a new value for a given key
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-
Method Details
-
get
Retrieve an entry from the cache, potentially triggering generation of the value.- Parameters:
key
- the key to retrieve the entry for- Returns:
- the cached or newly generated value
-
capacity
public int capacity()Return the maximum number of entries in the cache.- See Also:
-
sizeLimit
Deprecated.in favor ofcapacity()
as of 6.0.Return the maximum number of entries in the cache. -
size
public int size()Return the current size of the cache.- See Also:
-
clear
public void clear()Immediately remove all entries from this cache. -
contains
Determine whether the given key is present in this cache.- Parameters:
key
- the key to check for- Returns:
true
if the key is present,false
if there was no matching key
-
remove
Immediately remove the given key and any associated value.- Parameters:
key
- the key to evict the entry for- Returns:
true
if the key was present before,false
if there was no matching key
-
capacity()
as of 6.0.