Package org.apache.calcite.util

Class LazyReference<T>

java.lang.Object

org.apache.calcite.util.LazyReference<T>

Type Parameters:

T - Element Type

public class LazyReference<T>
extends Object

This class can is able to do a lazy initiaization of an object based on a Supplier.

In contrast to Suppliers.memoize, the supplier is passed at the later point in time, during the call to getOrCompute. This allows the usage in abstract base classes with a supplier method, implemented in a derived class.

Constructor Summary

Constructors

Constructor	Description
LazyReference()

Method Summary

Modifier and Type	Method	Description
T	getOrCompute(Supplier<T> supplier)	Atomically sets the value to supplier.get() if the current value was not set yet.
void	reset()	Resets the current value.

Methods inherited from class java.lang.Object

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

Constructor Details

LazyReference

public LazyReference()

Method Details

getOrCompute

public T getOrCompute(Supplier<T> supplier)

Atomically sets the value to supplier.get() if the current value was not set yet.

This method is reentrant. Different threads will get the same result.

Parameters:

supplier - supplier for the new value

Returns:

the current value.

reset

public void reset()

Resets the current value.