ca.uhn.hl7v2.concurrent

Class BlockingHashMap<K,V>

java.lang.Object

ca.uhn.hl7v2.concurrent.BlockingHashMap<K,V>

Type Parameters:

K -

V -

All Implemented Interfaces:

BlockingMap<K,V>, Map<K,V>

public class BlockingHashMap<K,V>
extends Object
implements BlockingMap<K,V>

Default Implementation of a BlockingMap.

Note: While it is not actively prevented that more then one thread waits for an entry, it is not guaranteed that all waiting threads will receive the entry once it became available. Other implementations may choose to count the waiting threads and/or to remove an available value after a grace period.

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
BlockingHashMap()
BlockingHashMap(ExecutorService executor)

Method Summary

Methods

Modifier and Type	Method and Description
Future<V>	asyncPoll(K key, long timeout, TimeUnit unit) Polls for an entry in a background thread.
Future<V>	asyncTake(K key) Waits for an entry in a background thread.
void	clear() Clears all existing entries.
boolean	containsKey(Object key) Returns true if an entry with the given key is available
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key) Returns an available entry without removing it from the map
boolean	give(K key, V value) Adds an entry only if there's already a consumer waiting for the value.
boolean	isEmpty() Returns true if no entry is available for consumers
Set<K>	keySet() Returns the keys of available entries
V	poll(K key, long timeout, TimeUnit unit) Waits for the specified amount of time for an entry with the given key and returns the associated value.
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> t)
V	remove(Object key) Removes an entry, regardless whether a value has been set or not.
int	size() Returns the number of available values
V	take(K key) Waits for an entry for the given key and returns the associated value.
Collection<V>	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

BlockingHashMap

public BlockingHashMap()

BlockingHashMap

public BlockingHashMap(ExecutorService executor)

Method Detail

keySet

public Set<K> keySet()

Returns the keys of available entries

Specified by:

keySet in interface Map<K,V>

See Also:

Map.keySet()

get

public V get(Object key)

Returns an available entry without removing it from the map

Specified by:

get in interface Map<K,V>

See Also:

Map.get(java.lang.Object)

containsKey

public boolean containsKey(Object key)

Returns true if an entry with the given key is available

Specified by:

containsKey in interface Map<K,V>

See Also:

Map.containsKey(java.lang.Object)

put

public V put(K key,
    V value)

Specified by:

put in interface Map<K,V>

See Also:

Map.put(java.lang.Object, java.lang.Object)

give

public boolean give(K key,
           V value)

Description copied from interface: BlockingMap

Adds an entry only if there's already a consumer waiting for the value.

Specified by:

give in interface BlockingMap<K,V>

Parameters:

key - key for the entry to be added

value - entry to be added

Returns:

true if entry was added and a consumer is already waiting for the value, false otherwise

See Also:

BlockingMap.give(java.lang.Object, java.lang.Object)

take

public V take(K key)
       throws InterruptedException

Description copied from interface: BlockingMap

Waits for an entry for the given key and returns the associated value. May return null if the producer withdraws the entry without providing a value.

Specified by:

take in interface BlockingMap<K,V>

Parameters:

key - key for the entry

Returns:

the value of the entry

Throws:

InterruptedException

asyncTake

public Future<V> asyncTake(K key)
                    throws InterruptedException

Description copied from interface: BlockingMap

Waits for an entry in a background thread.

Specified by:

asyncTake in interface BlockingMap<K,V>

Parameters:

key - key for the entry

Returns:

Future the result

Throws:

InterruptedException

poll

public V poll(K key,
     long timeout,
     TimeUnit unit)
       throws InterruptedException

Description copied from interface: BlockingMap

Waits for the specified amount of time for an entry with the given key and returns the associated value. Returns null if no value was provided within the poll time. May return null if the producer withdraws the entry without providing a value.

Specified by:

poll in interface BlockingMap<K,V>

Parameters:

key - key for the entry

timeout - timeout before the methods returns

unit - time unit used in conjunction with timout

Returns:

the value of the entry

Throws:

InterruptedException

asyncPoll

public Future<V> asyncPoll(K key,
                  long timeout,
                  TimeUnit unit)

Description copied from interface: BlockingMap

Polls for an entry in a background thread.

Specified by:

asyncPoll in interface BlockingMap<K,V>

Parameters:

key - key for the entry

Returns:

Future the result

isEmpty

public boolean isEmpty()

Returns true if no entry is available for consumers

Specified by:

isEmpty in interface Map<K,V>

See Also:

Map.isEmpty()

size

public int size()

Returns the number of available values

Specified by:

size in interface Map<K,V>

See Also:

Map.size()

remove

public V remove(Object key)

Removes an entry, regardless whether a value has been set or not. Waiting consumers will receive a null value.

Specified by:

remove in interface Map<K,V>

See Also:

Map.remove(java.lang.Object)

clear

public void clear()

Clears all existing entries. Waiting consumers will receive a null value for each removed entry.

Specified by:

clear in interface Map<K,V>

See Also:

Map.clear()

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

entrySet

public Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

putAll

public void putAll(Map<? extends K,? extends V> t)

Specified by:

putAll in interface Map<K,V>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>