net.spy.util
Class TimeStampedHashMap<K,V>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<K,V>
          net.spy.util.TimeStampedHashMap<K,V>

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<K,V>

public class TimeStampedHashMap<K,V>
extends java.util.HashMap<K,V>

A HashMap that remembers when it was accessed. Good for caching and stuff like that.

See Also:

Serialized Form

Constructor Summary

TimeStampedHashMap()
Get an instance of TimeStampedHashMap.

Method Summary

V	get(java.lang.Object key) Get an object from the map.
long	getGetAge() How many milliseconds ago was the last get operation?
long	getHits() Get the number of hits (number of requests for items that were actually there).
long	getLastGet() Find out the last time this thing last had a Get.
long	getLastPut() Find out the last time this thing last had a Put.
long	getMisses() Get the number of misses (number of requests for items that were not actually there).
long	getNumPuts() Get the total number of put() invocations.
long	getPutAge() How many milliseconds ago was the last put operation?
long	getTimestamp() Find out the last time this thing was used (put or get was called).
long	getUseAge() How many milliseconds ago was the last put or get operation?
long	getWatermark() Get the watermark (maximum number of objects seen at any one time).
V	put(K key, V value) Put an object into the map.

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, isEmpty, keySet, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

TimeStampedHashMap

public TimeStampedHashMap()

Get an instance of TimeStampedHashMap.

Method Detail

get

public V get(java.lang.Object key)

Get an object from the map.

Specified by:

get in interface java.util.Map<K,V>

Overrides:

get in class java.util.HashMap<K,V>

Parameters:

key - the object to get

Returns:

the object, or null if it's missing

put

public V put(K key,
             V value)

Put an object into the map.

Specified by:

put in interface java.util.Map<K,V>

Overrides:

put in class java.util.HashMap<K,V>

Parameters:

key - the key to store

value - the value to store

Returns:

the object that got displaced for this store, or null

getTimestamp

public long getTimestamp()

Find out the last time this thing was used (put or get was called).

getLastGet

public long getLastGet()

Find out the last time this thing last had a Get.

getLastPut

public long getLastPut()

Find out the last time this thing last had a Put.

getPutAge

public long getPutAge()

How many milliseconds ago was the last put operation?

getGetAge

public long getGetAge()

How many milliseconds ago was the last get operation?

getUseAge

public long getUseAge()

How many milliseconds ago was the last put or get operation?

getHits

public long getHits()

Get the number of hits (number of requests for items that were actually there).

getMisses

public long getMisses()

Get the number of misses (number of requests for items that were not actually there).

getWatermark

public long getWatermark()

Get the watermark (maximum number of objects seen at any one time).

getNumPuts

public long getNumPuts()

Get the total number of put() invocations.