org.enhydra.dods.cache.hash
Class DODSLinkedHashCache

java.lang.Object
  org.enhydra.dods.cache.hash.LinkedHashCache
      org.enhydra.dods.cache.hash.DODSLinkedHashCache

All Implemented Interfaces:

java.util.Map, DODSCache, CacheStatistics

public class DODSLinkedHashCache
extends LinkedHashCache
implements DODSCache

DODSLinkedHashCache class implements LRU cache (for storing data objects (or DataStruct objects), or simple queries, or complex queries), and provides query statistics about the cache (query number, cache hits number, their get/set/increment methods, percents of used cache, cache hits,...).

Version:

2.0 15.06.2003.

Author:

Tanja Jovanovic, Nenad Vico, Zorica Suvajdzin

Nested Class Summary

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

java.util.Map.Entry<K,V>

Field Summary

protected int	cacheAccessNum Total number of times the cache was accessed.
protected int	cacheHitsNum Number of queries performed on the cache successfully.

Fields inherited from class org.enhydra.dods.cache.hash.LinkedHashCache

maxEntries

Method Summary

void	clearStatistics() Clears statistics.
int	getCacheAccessNum() Returns total number of times the cache was accessed.
int	getCacheHitsNum() Returns number of queries performed on the cache successfully.
double	getCacheHitsPercents() Returns how much queries performed on the cache were successful.
double	getUsedPercents() Returns how much cache is currently used.
void	incrementCacheAccessNum(int num) Increases total number of times the cache was accessed.
void	incrementCacheHitsNum(int num) Increases number of queries performed on the cache successfully for one.
boolean	isNeedToSynchronize()
void	setCacheAccessNum(int num) Sets total number of times the cache was accessed.
void	setCacheHitsNum(int cacheHitsNum) Sets number of queries performed on the cache successfully.

Methods inherited from class org.enhydra.dods.cache.hash.LinkedHashCache

add, clear, containsKey, containsValue, entrySet, equals, get, getMaxEntries, hashCode, isEmpty, keySet, put, putAll, remove, setMaxEntries, size, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.enhydra.dods.cache.base.DODSCache

add, getMaxEntries, setMaxEntries

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Field Detail

cacheAccessNum

protected int cacheAccessNum

Total number of times the cache was accessed.

cacheHitsNum

protected int cacheHitsNum

Number of queries performed on the cache successfully.

Method Detail

getCacheAccessNum

public int getCacheAccessNum()

Returns total number of times the cache was accessed.

Specified by:

getCacheAccessNum in interface CacheStatistics

Returns:

total number of times the cache was accessed.

setCacheAccessNum

public void setCacheAccessNum(int num)

Sets total number of times the cache was accessed.

Specified by:

setCacheAccessNum in interface CacheStatistics

Parameters:

num - Total number of times the cache was accessed.

incrementCacheAccessNum

public void incrementCacheAccessNum(int num)

Increases total number of times the cache was accessed.

Specified by:

incrementCacheAccessNum in interface CacheStatistics

getCacheHitsNum

public int getCacheHitsNum()

Returns number of queries performed on the cache successfully.

Specified by:

getCacheHitsNum in interface CacheStatistics

Returns:

Number of queries performed on the cache successfully.

setCacheHitsNum

public void setCacheHitsNum(int cacheHitsNum)

Sets number of queries performed on the cache successfully.

Specified by:

setCacheHitsNum in interface CacheStatistics

Parameters:

cacheHitsNum - Number of queries performed on the cache successfully.

incrementCacheHitsNum

public void incrementCacheHitsNum(int num)

Increases number of queries performed on the cache successfully for one.

Specified by:

incrementCacheHitsNum in interface CacheStatistics

getUsedPercents

public double getUsedPercents()

Returns how much cache is currently used. This value is given in percents. If cache is unbounded, method returns 100%.

Specified by:

getUsedPercents in interface CacheStatistics

Returns:

Percents - how much cache is currently used.

getCacheHitsPercents

public double getCacheHitsPercents()

Returns how much queries performed on the cache were successful. This value is given in percents.

Specified by:

getCacheHitsPercents in interface CacheStatistics

Returns:

Percents - how much queries performed on the cache were successful.

clearStatistics

public void clearStatistics()

Clears statistics.

Specified by:

clearStatistics in interface CacheStatistics

isNeedToSynchronize

public boolean isNeedToSynchronize()

Specified by:

isNeedToSynchronize in interface DODSCache