LruCache

public class LruCache
extends Object

java.lang.Object
   ↳ androidx.collection.LruCache<K, V>


Static library version of android.util.LruCache. Used to write apps that run on API levels prior to 12. When running on API level 12 or above, this implementation is still used; it does not try to switch to the framework's implementation. See the framework SDK documentation for a class overview.

Summary

Public constructors

LruCache(int maxSize)

Public methods

final int createCount()

Returns the number of times create(Object) returned a value.

final void evictAll()

Clear the cache, calling entryRemoved(boolean, K, V, V) on each removed entry.

final int evictionCount()

Returns the number of values that have been evicted.

final V get(K key)

Returns the value for key if it exists in the cache or can be created by #create.

final int hitCount()

Returns the number of times get(K) returned a value that was already present in the cache.

final int maxSize()

For caches that do not override sizeOf(K, V), this returns the maximum number of entries in the cache.

final int missCount()

Returns the number of times get(K) returned null or required a new value to be created.

final V put(K key, V value)

Caches value for key.

final int putCount()

Returns the number of times put(K, V) was called.

final V remove(K key)

Removes the entry for key if it exists.

void resize(int maxSize)

Sets the size of the cache.

final int size()

For caches that do not override sizeOf(K, V), this returns the number of entries in the cache.

final Map<K, V> snapshot()

Returns a copy of the current contents of the cache, ordered from least recently accessed to most recently accessed.

final String toString()
void trimToSize(int maxSize)

Remove the eldest entries until the total of remaining entries is at or below the requested size.

Protected methods

V create(K key)

Called after a cache miss to compute a value for the corresponding key.

void entryRemoved(boolean evicted, K key, V oldValue, V newValue)

Called for entries that have been evicted or removed.

int sizeOf(K key, V value)

Returns the size of the entry for key and value in user-defined units.

Inherited methods

Public constructors

LruCache

public LruCache (int maxSize)

Parameters
maxSize int: for caches that do not override sizeOf(K, V), this is the maximum number of entries in the cache. For all other caches, this is the maximum sum of the sizes of the entries in this cache.

Public methods

createCount

public final int createCount ()

Returns the number of times create(Object) returned a value.

Returns
int

evictAll

public final void evictAll ()

Clear the cache, calling entryRemoved(boolean, K, V, V) on each removed entry.

evictionCount

public final int evictionCount ()

Returns the number of values that have been evicted.

Returns
int

get

public final V get (K key)

Returns the value for key if it exists in the cache or can be created by #create. If a value was returned, it is moved to the head of the queue. This returns null if a value is not cached and cannot be created.

Parameters
key K

Returns
V

hitCount

public final int hitCount ()

Returns the number of times get(K) returned a value that was already present in the cache.

Returns
int

maxSize

public final int maxSize ()

For caches that do not override sizeOf(K, V), this returns the maximum number of entries in the cache. For all other caches, this returns the maximum sum of the sizes of the entries in this cache.

Returns
int

missCount

public final int missCount ()

Retur