ConcurrentCacheMap (TomP2P 4.2 API)

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net.tomp2p.utils
Class ConcurrentCacheMap<K,V>

java.lang.Object
  net.tomp2p.utils.ConcurrentCacheMap<K,V>

All Implemented Interfaces:: ConcurrentMap<K,V>, Map<K,V>

public class ConcurrentCacheMap<K,V>
extends Object
implements ConcurrentMap<K,V>
extends Object
implements ConcurrentMap<K,V>

A map with expiration and more or less LRU. Since the maps are separated in segments, the LRU is done for each segment. A segment is chosen based on the hash of the key. If one segments is more loaded than another, then an entry of the loaded segment may get evicted before an entry used least recently from an other segment. The expiration is done best effort. There is no thread checking for timed out entries since the cache has a fixed size. Once an entry times out, it remains in the map until it either is accessed or evicted. A test showed that for the default entry size of 1024, this map has a size of 967 if 1024 items are inserted. This is due to the segmentation and hashing.

Author:: Thomas Bocek

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map
`Map.Entry<K,V>`

Field Summary
`static int`	`DEFAULT_TIME_TO_LIVE`
`static int`	`MAX_ENTRIES`
`static int`	`SEGMENT_NR`

Constructor Summary
`ConcurrentCacheMap()` Creates a new instance of ConcurrentCacheMap using the supplied values and a `CacheMap` for the internal data structure.
`ConcurrentCacheMap(int timeToLive)` Creates a new instance of ConcurrentCacheMap using the supplied values and a `CacheMap` for the internal data structure.
`ConcurrentCacheMap(int timeToLive, int maxEntries, boolean refreshTimeout)` Creates a new instance of ConcurrentCacheMap using the supplied values and a `CacheMap` for the internal data structure.

Method Summary
`void`	`clear()`
`boolean`	`containsKey(Object key)`
`boolean`	`containsValue(Object value)`
`Set<Map.Entry<K,V>>`	`entrySet()`
`boolean`	`equals(Object obj)`
`int`	`expiredCounter()`
`V`	`get(Object key)`
`int`	`hashCode()`
`boolean`	`isEmpty()`
`Set<K>`	`keySet()`
`V`	`put(K key, V value)`
`void`	`putAll(Map<? extends K,? extends V> inMap)`
`V`	`putIfAbsent(K key, V value)` This does not reset the timer!
`V`	`remove(Object key)`
`boolean`	`remove(Object key, Object value)`
`V`	`replace(K key, V value)`
`boolean`	`replace(K key, V oldValue, V newValue)`
`int`	`size()`
`Collection<V>`	`values()`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

Field Detail

SEGMENT_NR

public static final int SEGMENT_NR

See Also:: Constant Field Values

MAX_ENTRIES

public static final int MAX_ENTRIES

See Also:: Constant Field Values

DEFAULT_TIME_TO_LIVE

public static final int DEFAULT_TIME_TO_LIVE

See Also:: Constant Field Values

Constructor Detail