Modifier and Type	Class and Description
public static interface	Cache.CycleHandler< Key type. K> Should a cycle be detected during computation of a value for given key, this interface allows client code to register a callback that would get invoked in such a case.
private class	Cache.OriginThreadAwareFuture Helper class, that remembers the future task origin thread, so that cycles could be detected.

Modifier and Type	Field and Description
private final ConcurrentHashMap<K, Cache<K, V>.OriginThreadAwareFuture>	cache
private final Computable<K, V>	computable
private final Cache.CycleHandler<K>	cycleHandler
private static final Cache.CycleHandler<Object>	EMPTY_HANDLER

Access	Constructor and Description
public	Cache(Computable<K, V> computable) Create new cache with given computable to compute values.
public	Cache(Computable<K, V> computable, Cache.CycleHandler<K> cycleHandler) Create new cache with given computable and cycle handler.

Modifier and Type	Method and Description
public void	clear() Empty cache.
public V	compute(final K key) Implements org.glassfish.hk2.utilities.cache.Computable.compute. Defines an expensive computation to retrieve value V from key K.
public boolean	Returns: true if given key is present in the cache. containsKey(final K key) Returns true if the key has already been cached.
public void	remove(final K item key. key) Remove item from the cache.
public int	Returns: The number of elements in the cache size() Returns the size of the cache

cache	back to summary
private final ConcurrentHashMap<K, Cache<K, V>.OriginThreadAwareFuture> cache

computable	back to summary
private final Computable<K, V> computable

cycleHandler	back to summary
private final Cache.CycleHandler<K> cycleHandler

EMPTY_HANDLER	back to summary
private static final Cache.CycleHandler<Object> EMPTY_HANDLER

Cache	back to summary
public Cache(Computable<K, V> computable) Create new cache with given computable to compute values. Detected cycles will be ignored as there is a no-op cycle handler registered by default. Annotations @SuppressWarnings:unchecked

Cache	back to summary
public Cache(Computable<K, V> computable, Cache.CycleHandler<K> cycleHandler) Create new cache with given computable and cycle handler.

clear	back to summary
public void clear() Empty cache.

compute	back to summary
public V compute(final K key) Implements org.glassfish.hk2.utilities.cache.Computable.compute. Doc from org.glassfish.hk2.utilities.cache.Computable.compute. Defines an expensive computation to retrieve value V from key K. Annotations @Override

containsKey	back to summary
public boolean containsKey(final K key) Returns true if the key has already been cached. Returns:boolean true if given key is present in the cache.

remove	back to summary
public void remove(final K key) Remove item from the cache. Parameters key:K item key.

size	back to summary
public int size() Returns the size of the cache Returns:int The number of elements in the cache

Modifier and Type	Method and Description
public void	handleCycle(K instance that caused the cycle. key) Handle cycle that was detected while computing a cache value for given key.

handleCycle	back to summary
public void handleCycle(K key) Handle cycle that was detected while computing a cache value for given key. This method would typically just throw a runtime exception. Parameters key:K instance that caused the cycle.

org.glassfish.hk2.utilities.cache back to summary

private Class Cache.OriginThreadAwareFuture

Class Inheritance

extends Object
implements Future<V>

java.lang.Object
org.glassfish.hk2.utilities.cache.Cache.OriginThreadAwareFuture

All Implemented Interfaces

java.util.concurrent.Future

Helper class, that remembers the future task origin thread, so that cycles could be detected. If any thread starts computation for given key and the same thread requests the computed value before the computation stops, a cycle is detected and registered cycle handler is called.

Field Summary

Modifier and Type	Field and Description
private final FutureTask<V>	future
private volatile long	threadId

Constructor Summary

Access	Constructor and Description
pack-priv	OriginThreadAwareFuture(Cache<K, V> cache, final K key)

Method Summary

Modifier and Type	Method and Description
public boolean	cancel(boolean mayInterruptIfRunning) Implements java.util.concurrent.Future.cancel. Attempts to cancel execution of this task.
public boolean	equals(Object obj) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public V	get() Implements java.util.concurrent.Future.get. Waits if necessary for the computation to complete, and then retrieves its result.
public V	get(long timeout, TimeUnit unit) Implements java.util.concurrent.Future.get. Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for this object.
public boolean	isCancelled() Implements java.util.concurrent.Future.isCancelled. Returns `true` if this task was cancelled before it completed normally.
public boolean	isDone() Implements java.util.concurrent.Future.isDone. Returns `true` if this task completed.
public void	run()

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

Field Detail

future	back to summary
private final FutureTask<V> future

threadId	back to summary
private volatile long threadId

Constructor Detail

OriginThreadAwareFuture	back to summary
pack-priv OriginThreadAwareFuture(Cache<K, V> cache, final K key)

Method Detail

cancel back to summary

cancel	back to summary
public boolean cancel(boolean mayInterruptIfRunning) Implements java.util.concurrent.Future.cancel. Doc from java.util.concurrent.Future.cancel. Attempts to cancel execution of this task. This method has no effect if the task is already completed or cancelled, or could not be cancelled for some other reason. Otherwise, if this task has not started when `cancel` is called, this task should never run. If the task has already started, then the `mayInterruptIfRunning` parameter determines whether the thread executing this task (when known by the implementation) is interrupted in an attempt to stop the task. The return value from this method does not necessarily indicate whether the task is now cancelled; use `isCancelled`. Annotations @Override

public boolean cancel(boolean mayInterruptIfRunning)

Implements java.util.concurrent.Future.cancel.

Doc from java.util.concurrent.Future.cancel.

Attempts to cancel execution of this task. This method has no effect if the task is already completed or cancelled, or could not be cancelled for some other reason. Otherwise, if this task has not started when cancel is called, this task should never run. If the task has already started, then the mayInterruptIfRunning parameter determines whether the thread executing this task (when known by the implementation) is interrupted in an attempt to stop the task.

The return value from this method does not necessarily indicate whether the task is now cancelled; use isCancelled.

Annotations

@Override

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Annotations @SuppressWarnings:unchecked @Override

public boolean equals(Object obj)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Annotations

@SuppressWarnings:unchecked
@Override

get	back to summary
public V get() throws InterruptedException, ExecutionException Implements java.util.concurrent.Future.get. Doc from java.util.concurrent.Future.get. Waits if necessary for the computation to complete, and then retrieves its result. Annotations @Override Exceptions InterruptedException: if the current thread was interrupted while waiting ExecutionException: if the computation threw an exception

get

back to summary

public V get() throws InterruptedException, ExecutionException

Implements java.util.concurrent.Future.get.

Doc from java.util.concurrent.Future.get.

Waits if necessary for the computation to complete, and then retrieves its result.

Annotations

@Override

Exceptions

InterruptedException:: if the current thread was interrupted while waiting
ExecutionException:: if the computation threw an exception

get	back to summary
public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException Implements java.util.concurrent.Future.get. Doc from java.util.concurrent.Future.get. Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available. Annotations @Override Exceptions InterruptedException: if the current thread was interrupted while waiting ExecutionException: if the computation threw an exception TimeoutException: if the wait timed out

get

back to summary

public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException

Implements java.util.concurrent.Future.get.

Doc from java.util.concurrent.Future.get.

Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.

Annotations

@Override

Exceptions

InterruptedException:: if the current thread was interrupted while waiting
ExecutionException:: if the computation threw an exception
TimeoutException:: if the wait timed out

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Annotations

@Override

isCancelled back to summary

isCancelled	back to summary
public boolean isCancelled() Implements java.util.concurrent.Future.isCancelled. Doc from java.util.concurrent.Future.isCancelled. Returns `true` if this task was cancelled before it completed normally. Annotations @Override

public boolean isCancelled()

Implements java.util.concurrent.Future.isCancelled.

Doc from java.util.concurrent.Future.isCancelled.

Returns true if this task was cancelled before it completed normally.

Annotations

@Override

isDone back to summary

isDone	back to summary
public boolean isDone() Implements java.util.concurrent.Future.isDone. Doc from java.util.concurrent.Future.isDone. Returns `true` if this task completed. Completion may be due to normal termination, an exception, or cancellation -- in all of these cases, this method will return `true`. Annotations @Override

public boolean isDone()

Implements java.util.concurrent.Future.isDone.

Doc from java.util.concurrent.Future.isDone.

Returns true if this task completed. Completion may be due to normal termination, an exception, or cancellation -- in all of these cases, this method will return true.

Annotations

@Override

run	back to summary
public void run()

public Class Cache<K, V>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public Interface Cache.CycleHandler<K>

Method Summary

Method Detail

private Class Cache.OriginThreadAwareFuture

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail