com.android.tools.build.apkzlib.utils

Class CachedSupplier<T>

java.lang.Object

com.android.tools.build.apkzlib.utils.CachedSupplier<T>

public class CachedSupplier<T>
extends java.lang.Object

Supplier that will cache a computed value and always supply the same value. It can be used to lazily compute data. For example:

 CachedSupplier<Integer> value = new CachedSupplier<>(() -> {
     Integer result;
     // Do some expensive computation.
     return result;
 });

 if (a) {
     // We need the result of the expensive computation.
     Integer r = value.get();
 }

 if (b) {
     // We also need the result of the expensive computation.
     Integer r = value.get();
 }

 // If neither a nor b are true, we avoid doing the computation at all.
 

Constructor Summary

Constructors

Constructor and Description
CachedSupplier(java.util.function.Supplier<T> supplier) Creates a new supplier.

Method Summary

Modifier and Type	Method and Description
T	get() Obtains the value.
boolean	isValid() Checks if the contents of the cache are valid.
void	precomputed(T t) In some cases, we may be able to precompute the cache value (or load it from somewhere we had previously stored it).
void	reset() Resets the cache forcing a get() on the supplier next time get() is invoked.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CachedSupplier

public CachedSupplier(@Nonnull
                      java.util.function.Supplier<T> supplier)

Creates a new supplier.

Method Detail

get

public T get()

Obtains the value.

Returns:

the value, either cached (if one exists) or computed

reset

public void reset()

Resets the cache forcing a get() on the supplier next time get() is invoked.

precomputed

public void precomputed(T t)

In some cases, we may be able to precompute the cache value (or load it from somewhere we had previously stored it). This method allows the cache value to be loaded.

If this method is invoked, then an invocation of get() will not trigger an invocation of the supplier provided in the constructor.

Parameters:

t - the new cache contents; will replace any currently cache content, if one exists

isValid

public boolean isValid()

Checks if the contents of the cache are valid.

Returns:

are there valid contents in the cache?