com.kheops.util

Class KMemoryDataCache

java.lang.Object

com.kheops.util.KAbstractDataCache

com.kheops.util.KMemoryDataCache

All Implemented Interfaces:

KSchedulerClient

public class KMemoryDataCache
extends KAbstractDataCache
implements KSchedulerClient

A class used to store and retrieve data stored on memory.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	KMemoryDataCache.CachedData This inner-class encapsutale the concept of cache It constains the data as well as the amount of time that the data can remain in memory before it becomes expired

Field Summary

Fields inherited from class com.kheops.util.KAbstractDataCache

currentSize, hits, maximumSize, misses

Constructor Summary

Constructors

Constructor and Description
KMemoryDataCache(long maximumSize) Constructs a KMemoryDataCache with the specified maximum size

Method Summary

Modifier and Type	Method and Description
boolean	contains(java.lang.String key) Checks if the table contains the data with the specified keys
void	export(KAbstractDataCache cache)
long	getCount()
long	getCount(java.lang.String partialKey)
long	getCurrentSize() Gets the memory cache current size
long	getCurrentSize(java.lang.String partialKey)
long	getMaximumSize() Gets the memory cache maximum allowed size
void	remove(java.lang.String key) Removes the memory cache with the specified key
void	removeAll()
void	removeMatching(java.lang.String partialKey)
byte[]	retrieve(java.lang.String key) Retrieves the data previously stored using the specified key.
void	schCallback(int jobId) This method is called by the KScheduler to remove the expired data
void	store(java.lang.String key, byte[] data)
void	store(java.lang.String key, byte[] data, long timeTolive) Stores the specified data in memory cache using the specified key.

Methods inherited from class com.kheops.util.KAbstractDataCache

getHits, getMisses, getMonitoringInfo, getMonitoringInfo

Methods inherited from class java.lang.Object

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

Constructor Detail

KMemoryDataCache

public KMemoryDataCache(long maximumSize)

Constructs a KMemoryDataCache with the specified maximum size

Parameters:

maximumSize - the maximum size of memory data cache allowed

Method Detail

store

public void store(java.lang.String key,
                  byte[] data)

Specified by:

store in class KAbstractDataCache

store

public void store(java.lang.String key,
                  byte[] data,
                  long timeTolive)

Stores the specified data in memory cache using the specified key. The specified time to live (in ms) is the data expiration time. After this time is expired, the data will be removed from the cache. If timeToLive is CacheConstants.CACHE_TIMEOUT_NEVER_EXPIRE, expiration will be disabled for this data (it will stay in cache until explicitly removed using the remove(String key) method.

Parameters:

key - the key of the KMemoryDataCache where to store the data

data - the data to be stored

timeTolive - amount of time before the data expires

retrieve

public byte[] retrieve(java.lang.String key)

Retrieves the data previously stored using the specified key. If the data does not exist, no exception is thrown but the method returns null.

Parameters:

key - unique identifier used to search for the corresponding data

Returns:

data the data retrieved from memory
this method keeps the count of sucessfull and unsecessfull data retrieval

contains

public boolean contains(java.lang.String key)

Checks if the table contains the data with the specified keys

Parameters:

key - the corresponding key

Returns:

the boolean value of the result

getCurrentSize

public long getCurrentSize()

Gets the memory cache current size

Overrides:

getCurrentSize in class KAbstractDataCache

Returns:

the current cache size

getMaximumSize

public long getMaximumSize()

Gets the memory cache maximum allowed size

Overrides:

getMaximumSize in class KAbstractDataCache

Returns:

the maximum cache size

remove

public void remove(java.lang.String key)

Removes the memory cache with the specified key

Parameters:

key - the key of the data to be removed

schCallback

public void schCallback(int jobId)

This method is called by the KScheduler to remove the expired data

Specified by:

schCallback in interface KSchedulerClient

Parameters:

jobId - the corresponding job Id

removeAll

public void removeAll()

Specified by:

removeAll in class KAbstractDataCache

removeMatching

public void removeMatching(java.lang.String partialKey)

Specified by:

removeMatching in class KAbstractDataCache

export

public void export(KAbstractDataCache cache)
            throws java.io.IOException

Specified by:

export in class KAbstractDataCache

Throws:

java.io.IOException

getCount

public long getCount()

Specified by:

getCount in class KAbstractDataCache

getCount

public long getCount(java.lang.String partialKey)

Specified by:

getCount in class KAbstractDataCache

getCurrentSize

public long getCurrentSize(java.lang.String partialKey)

Specified by:

getCurrentSize in class KAbstractDataCache