LruCache

open class LruCache<K : Any, V : Any>(maxSize: Int)(source)

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.

Parameters

maxSize

for caches that do not override sizeOf, 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.

Constructors

LruCache

fun LruCache(maxSize: Int)

Creates a new LruCache

Functions

create

protected open fun create(key: K): V?

Called after a cache miss to compute a value for the corresponding key. Returns the computed value or null if no value can be computed. The default implementation returns null.

createCount

fun createCount(): Int

Returns the number of times create returned a value.

entryRemoved

protected open fun entryRemoved( evicted: Boolean, key: K, oldValue: V, newValue: V?)

Called for entries that have been evicted or removed. This method is invoked when a value is evicted to make space, removed by a call to remove, or replaced by a call to put. The default implementation does nothing.

evictAll

fun evictAll()

Clear the cache, calling entryRemoved on each removed entry.

evictionCount

fun evictionCount(): Int

Returns the number of values that have been evicted.

get

operator fun get(key: K): V?

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.

hitCount

fun hitCount(): Int

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

maxSize

fun maxSize(): Int

For caches that do not override sizeOf, 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.

missCount

fun missCount(): Int

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

put

fun put(key: K, value: V): V?

Caches value for key. The value is moved to the head of the queue.

putCount

fun putCount(): Int

Returns the number of times put was called.

remove

fun remove(key: K): V?

Removes the entry for key if it exists.

resize

open fun resize(maxSize: Int)

Sets the size of the cache.

size

fun size(): Int

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

sizeOf

protected open fun sizeOf(key: K, value: V): Int

Returns the size of the entry for key and value in user-defined units. The default implementation returns 1 so that size is the number of entries and max size is the maximum number of entries.

snapshot

fun snapshot(): MutableMap<K, V>

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

toString

open override fun toString(): String

trimToSize

open fun trimToSize(maxSize: Int)

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