com.tangosol.net.cache
Class SimpleCacheStatistics

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.net.cache.SimpleCacheStatistics

All Implemented Interfaces:

CacheStatistics, Serializable

public class SimpleCacheStatistics
extends Base
implements CacheStatistics, Serializable

Implementation of the CacheStatistics class intended for use by a cache to maintain its statistics.

Since:

Coherence 2.2

Author:

cp 2003.06.02

Field Summary

protected long	m_cCacheHits The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the front map.
protected long	m_cCacheMisses The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the back map.
protected long	m_cCachePuts Total number of put operations since the last statistics reset.
protected long	m_cHitsMillis Total number of milliseconds used for get operations that were hits since the last statistics reset.
protected long	m_cMissesMillis Total number of milliseconds used for get operations that were misses since the last statistics reset.
protected long	m_cPutsMillis Total number of milliseconds used for put operations since the last statistics reset.

Constructor Summary

SimpleCacheStatistics()
Default constructor.

Method Summary

double	getAverageGetMillis() Determine the average number of milliseconds per get() invocation since the cache statistics were last reset.
double	getAverageHitMillis() Determine the average number of milliseconds per get() invocation that is a hit (answered using only the front map).
double	getAverageMissMillis() Determine the average number of milliseconds per get() invocation that is a miss (uses the back map).
double	getAveragePutMillis() Determine the average number of milliseconds per put() invocation since the cache statistics were last reset.
long	getCacheHits() Determine the rough number of cache hits since the cache statistics were last reset.
long	getCacheHitsMillis() Determine the total number of milliseconds (since that last statistics reset) for the get() operations for which an entry existed in this map.
long	getCacheMisses() Determine the rough number of cache misses since the cache statistics were last reset.
long	getCacheMissesMillis() Determine the total number of milliseconds (since that last statistics reset) for the get() operations for which no entry existed in this map.
double	getHitProbability() Determine the rough probability (0 <= p <= 1) that any particular invocation that could be answered using the front or the back will be handled by the front map, based on the statistics collected since the last reset of the cache statistics.
long	getTotalGets() Determine the total number of get() operations since the cache statistics were last reset.
long	getTotalGetsMillis() Determine the total number of milliseconds spent on get() operations since the cache statistics were last reset.
long	getTotalPuts() Determine the total number of put() operations since the cache statistics were last reset.
long	getTotalPutsMillis() Determine the total number of milliseconds spent on put() operations since the cache statistics were last reset.
void	registerHit() Register a cache hit (no timing information).
void	registerHit(long lStartMillis) Register a cache hit.
void	registerHits(int cHits, long lStartMillis) Register a multiple cache hit.
void	registerMiss() Register a cache miss (no timing information).
void	registerMiss(long lStartMillis) Register a cache miss.
void	registerMisses(int cMisses, long lStartMillis) Register a multiple cache miss.
void	registerPut(long lStartMillis) Register a cache put.
void	registerPuts(int cPuts, long lStartMillis) Register a multiple cache put.
void	resetHitStatistics() Reset the cache statistics.
String	toString() For debugging purposes, format the contents of the SimpleCachingStatistics in a human readable format.

Field Detail

m_cCacheHits

protected volatile long m_cCacheHits

The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the front map.

m_cCacheMisses

protected volatile long m_cCacheMisses

The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the back map.

m_cHitsMillis

protected volatile long m_cHitsMillis

Total number of milliseconds used for get operations that were hits since the last statistics reset.

m_cMissesMillis

protected volatile long m_cMissesMillis

Total number of milliseconds used for get operations that were misses since the last statistics reset.

m_cCachePuts

protected volatile long m_cCachePuts

Total number of put operations since the last statistics reset.

m_cPutsMillis

protected volatile long m_cPutsMillis

Total number of milliseconds used for put operations since the last statistics reset.

Constructor Detail

SimpleCacheStatistics

public SimpleCacheStatistics()

Default constructor.

Method Detail

getTotalGets

public long getTotalGets()

Determine the total number of get() operations since the cache statistics were last reset.

Specified by:

getTotalGets in interface CacheStatistics

Returns:

the total number of get() operations

getTotalGetsMillis

public long getTotalGetsMillis()

Determine the total number of milliseconds spent on get() operations since the cache statistics were last reset.

Specified by:

getTotalGetsMillis in interface CacheStatistics

Returns:

the total number of milliseconds processing get() operations

getAverageGetMillis

public double getAverageGetMillis()

Determine the average number of milliseconds per get() invocation since the cache statistics were last reset.

Specified by:

getAverageGetMillis in interface CacheStatistics

Returns:

the average number of milliseconds per get() operation

getTotalPuts

public long getTotalPuts()

Determine the total number of put() operations since the cache statistics were last reset.

Specified by:

getTotalPuts in interface CacheStatistics

Returns:

the total number of put() operations

getTotalPutsMillis

public long getTotalPutsMillis()

Determine the total number of milliseconds spent on put() operations since the cache statistics were last reset.

Specified by:

getTotalPutsMillis in interface CacheStatistics

Returns:

the total number of milliseconds processing put() operations

getAveragePutMillis

public double getAveragePutMillis()

Determine the average number of milliseconds per put() invocation since the cache statistics were last reset.

Specified by:

getAveragePutMillis in interface CacheStatistics

Returns:

the average number of milliseconds per put() operation

getCacheHits

public long getCacheHits()

Determine the rough number of cache hits since the cache statistics were last reset. A cache hit is an invocation that could be answered from the front or the back and is answered by data in the front map.

Specified by:

getCacheHits in interface CacheStatistics

Returns:

the number of get() calls that have been served by existing cache entries

getCacheHitsMillis

public long getCacheHitsMillis()

Description copied from interface: CacheStatistics

Determine the total number of milliseconds (since that last statistics reset) for the get() operations for which an entry existed in this map.

Specified by:

getCacheHitsMillis in interface CacheStatistics

Returns:

the total number of milliseconds (since that last statistics reset) for the get() operations that were answered by the front map

getAverageHitMillis

public double getAverageHitMillis()

Determine the average number of milliseconds per get() invocation that is a hit (answered using only the front map).

Specified by:

getAverageHitMillis in interface CacheStatistics

Returns:

the average number of milliseconds per cache hit

getCacheMisses

public long getCacheMisses()

Determine the rough number of cache misses since the cache statistics were last reset. A cache miss is an invocation that could be answered from the front or the back and is answered by data in the back map because the data is not in the front map.

Specified by:

getCacheMisses in interface CacheStatistics

Returns:

the number of get() calls that failed to find an existing cache entry because the requested key was not in the cache

getCacheMissesMillis

public long getCacheMissesMillis()

Description copied from interface: CacheStatistics

Determine the total number of milliseconds (since that last statistics reset) for the get() operations for which no entry existed in this map.

Specified by:

getCacheMissesMillis in interface CacheStatistics

Returns:

the total number of milliseconds (since that last statistics reset) for the get() operations that went to the back map

getAverageMissMillis

public double getAverageMissMillis()

Determine the average number of milliseconds per get() invocation that is a miss (uses the back map).

Specified by:

getAverageMissMillis in interface CacheStatistics

Returns:

the average number of milliseconds per cache miss

getHitProbability

public double getHitProbability()

Determine the rough probability (0 <= p <= 1) that any particular invocation that could be answered using the front or the back will be handled by the front map, based on the statistics collected since the last reset of the cache statistics.

Specified by:

getHitProbability in interface CacheStatistics

Returns:

the cache hit probability (0 <= p <= 1)

resetHitStatistics

public void resetHitStatistics()

Reset the cache statistics.

Specified by:

resetHitStatistics in interface CacheStatistics

toString

public String toString()

For debugging purposes, format the contents of the SimpleCachingStatistics in a human readable format.

Returns:

a String representation of this object

registerHit

public void registerHit()

Register a cache hit (no timing information).

registerHit

public void registerHit(long lStartMillis)

Register a cache hit.

Parameters:

lStartMillis - the time when the get operation started

registerHits

public void registerHits(int cHits,
                         long lStartMillis)

Register a multiple cache hit.

Parameters:

cHits - the number of hits

lStartMillis - the time when the get operation started

registerMiss

public void registerMiss()

Register a cache miss (no timing information).

registerMiss

public void registerMiss(long lStartMillis)

Register a cache miss.

Parameters:

lStartMillis - the time when the get operation started

registerMisses

public void registerMisses(int cMisses,
                           long lStartMillis)

Register a multiple cache miss.

Parameters:

cMisses - the number of misses

lStartMillis - the time when the get operation started

registerPut

public void registerPut(long lStartMillis)

Register a cache put.

Parameters:

lStartMillis - the time when the put operation started

registerPuts

public void registerPuts(int cPuts,
                         long lStartMillis)

Register a multiple cache put.

Parameters:

cPuts - the number of puts

lStartMillis - the time when the put operation started