Package com.twelvemonkeys.util
Class TimeoutMap<K,V>
java.lang.Object
java.util.AbstractMap<K,V>
com.twelvemonkeys.util.AbstractDecoratedMap<K,V>
com.twelvemonkeys.util.TimeoutMap<K,V>
- All Implemented Interfaces:
ExpiringMap<K,
,V> Serializable
,Cloneable
,Map<K,
V>
public class TimeoutMap<K,V>
extends AbstractDecoratedMap<K,V>
implements ExpiringMap<K,V>, Serializable, Cloneable
A
Map
implementation that removes (expires) its elements after
a given period. The map is by default backed by a HashMap
,
or can be instantiated with any given Map
as backing.
Notes to consider when using this map:
- Elements may not expire on the exact millisecond as expected.
- The value returned by the
size()
method of the map, or any of its collection views, may not represent the exact number of entries in the map at any given time. - Elements in this map may expire at any time
(but never between invocations of
Iterator.hasNext()
andIterator.next()
orIterator.remove()
, when iterating the collection views).
- Version:
- $Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/util/TimeoutMap.java#2 $
- See Also:
-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate class
private class
private class
Keeps track of timed objectsprivate class
Note: Iterating through this iterator will remove any expired values.private class
Nested classes/interfaces inherited from class com.twelvemonkeys.util.AbstractDecoratedMap
AbstractDecoratedMap.BasicEntry<K,
V>, AbstractDecoratedMap.EntrySet, AbstractDecoratedMap.KeySet, AbstractDecoratedMap.Values Nested classes/interfaces inherited from class java.util.AbstractMap
AbstractMap.SimpleEntry<K,
V>, AbstractMap.SimpleImmutableEntry<K, V> -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected long
Expiry timeprivate long
Fields inherited from class com.twelvemonkeys.util.AbstractDecoratedMap
entries, modCount
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Constructor Summary
ConstructorsConstructorDescriptionCreates aTimeoutMap
with the default expiry time of 1 minute.TimeoutMap
(long pExpiryTime) Creates aTimeoutMap
with the given expiry time (milliseconds).TimeoutMap
(Map<? extends K, ? extends V> pContents) Creates aTimeoutMap
containing the same elements as the given map with the default expiry time of 1 minute.TimeoutMap
(Map<K, Map.Entry<K, V>> pBacking, Map<? extends K, ? extends V> pContents, long pExpiryTime) Creates aTimeoutMap
with the given expiry time (milliseconds). -
Method Summary
Modifier and TypeMethodDescriptionvoid
clear()
Removes all mappings from this map.boolean
containsKey
(Object pKey) Returnstrue
if this map contains a mapping for the specified pKey.(package private) TimeoutMap<K,
V>.TimedEntry createEntry
(K pKey, V pValue) entrySet()
Returns the value to which this map maps the specified pKey.long
Gets the maximum time any value will be kept in the map, before it expires.boolean
isEmpty()
Returnstrue
if this map contains no key-value mappings.keySet()
void
processRemoved
(Map.Entry pRemoved) May be used by clients as a call-back to notify when mappings expire from the map.Associates the specified pValue with the specified pKey in this map (optional operation).Removes the mapping for this pKey from this map if present (optional operation).protected void
Removes any expired mappings.private void
removeExpiredEntriesSynced
(long pTime) Okay, I guess this do resemble DCL...void
setExpiryTime
(long pExpiryTime) Sets the maximum time any value will be kept in the map, before it expires.int
size()
Returns the number of key-value mappings in this map.values()
Methods inherited from class com.twelvemonkeys.util.AbstractDecoratedMap
clone, containsValue, getEntry, init, removeEntry
Methods inherited from class java.util.AbstractMap
equals, hashCode, putAll, toString
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, containsValue, equals, forEach, getOrDefault, hashCode, merge, putAll, putIfAbsent, remove, replace, replace, replaceAll
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Field Details
-
expiryTime
protected long expiryTimeExpiry time -
nextExpiryTime
private volatile long nextExpiryTime
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-
Constructor Details
-
TimeoutMap
public TimeoutMap()Creates aTimeoutMap
with the default expiry time of 1 minute. ThisTimeoutMap
will be backed by a newHashMap
instance.This is constructor is here to comply with the recommendations for "standard" constructors in the
Map
interface.- See Also:
-
TimeoutMap
Creates aTimeoutMap
containing the same elements as the given map with the default expiry time of 1 minute. ThisTimeoutMap
will be backed by a newHashMap
instance, and not the map passed in as a paramter.This is constructor is here to comply with the recommendations for "standard" constructors in the
Map
interface.- Parameters:
pContents
- the map whose mappings are to be placed in this map. May benull
.- See Also:
-
TimeoutMap
public TimeoutMap(long pExpiryTime) Creates aTimeoutMap
with the given expiry time (milliseconds). ThisTimeoutMap
will be backed by a newHashMap
instance.- Parameters:
pExpiryTime
- the expiry time (time to live) for elements in this map
-
TimeoutMap
public TimeoutMap(Map<K, Map.Entry<K, V>> pBacking, Map<? extends K, ? extends V> pContents, long pExpiryTime) Creates aTimeoutMap
with the given expiry time (milliseconds). ThisTimeoutMap
will be backed by the givenMap
.Note that structurally modifying the backing map directly (not through this map or its collection views), is not allowed, and will produce undeterministic exceptions.
- Parameters:
pBacking
- the map that will be used as backing.pContents
- the map whose mappings are to be placed in this map. May benull
.pExpiryTime
- the expiry time (time to live) for elements in this map
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Method Details
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getExpiryTime
public long getExpiryTime()Gets the maximum time any value will be kept in the map, before it expires.- Returns:
- the expiry time
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setExpiryTime
public void setExpiryTime(long pExpiryTime) Sets the maximum time any value will be kept in the map, before it expires. Removes any items that are older than the specified time.- Parameters:
pExpiryTime
- the expiry time (time to live) for elements in this map
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size
public int size()Returns the number of key-value mappings in this map. If the map contains more thanInteger.MAX_VALUE
elements, returnsInteger.MAX_VALUE
. -
isEmpty
public boolean isEmpty()Returnstrue
if this map contains no key-value mappings. -
containsKey
Returnstrue
if this map contains a mapping for the specified pKey.- Specified by:
containsKey
in interfaceMap<K,
V> - Overrides:
containsKey
in classAbstractDecoratedMap<K,
V> - Parameters:
pKey
- pKey whose presence in this map is to be tested.- Returns:
true
if this map contains a mapping for the specified pKey.
-
get
Returns the value to which this map maps the specified pKey. Returnsnull
if the map contains no mapping for this pKey. A return value ofnull
does not necessarily indicate that the map contains no mapping for the pKey; it's also possible that the map explicitly maps the pKey tonull
. ThecontainsKey
operation may be used to distinguish these two cases. -
put
Associates the specified pValue with the specified pKey in this map (optional operation). If the map previously contained a mapping for this pKey, the old pValue is replaced.- Specified by:
put
in interfaceMap<K,
V> - Specified by:
put
in classAbstractDecoratedMap<K,
V> - Parameters:
pKey
- pKey with which the specified pValue is to be associated.pValue
- pValue to be associated with the specified pKey.- Returns:
- previous pValue associated with specified pKey, or
null
if there was no mapping for pKey. Anull
return can also indicate that the map previously associatednull
with the specified pKey, if the implementation supportsnull
values.
-
remove
Removes the mapping for this pKey from this map if present (optional operation).- Specified by:
remove
in interfaceMap<K,
V> - Specified by:
remove
in classAbstractDecoratedMap<K,
V> - Parameters:
pKey
- pKey whose mapping is to be removed from the map.- Returns:
- previous value associated with specified pKey, or
null
if there was no mapping for pKey. Anull
return can also indicate that the map previously associatednull
with the specified pKey, if the implementation supportsnull
values.
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clear
public void clear()Removes all mappings from this map. -
createEntry
- Overrides:
createEntry
in classAbstractDecoratedMap<K,
V>
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removeExpiredEntries
protected void removeExpiredEntries()Removes any expired mappings. -
removeExpiredEntriesSynced
private void removeExpiredEntriesSynced(long pTime) Okay, I guess this do resemble DCL...- Parameters:
pTime
- now
-
values
-
entrySet
-
keySet
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newKeyIterator
- Specified by:
newKeyIterator
in classAbstractDecoratedMap<K,
V>
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newValueIterator
- Specified by:
newValueIterator
in classAbstractDecoratedMap<K,
V>
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newEntryIterator
- Specified by:
newEntryIterator
in classAbstractDecoratedMap<K,
V>
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processRemoved
Description copied from interface:ExpiringMap
May be used by clients as a call-back to notify when mappings expire from the map.- Specified by:
processRemoved
in interfaceExpiringMap<K,
V> - Parameters:
pRemoved
- the removed mapping
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