Guava: Google Core Libraries for Java 32.1.2-jre · com.google.common.cache.CacheStats

Modifier and Type	Field and Description
private final long	evictionCount
private final long	hitCount
private final long	loadExceptionCount
private final long	loadSuccessCount
private final long	missCount
private final long	totalLoadTime

Access	Constructor and Description
public	CacheStats(long hitCount, long missCount, long loadSuccessCount, long loadExceptionCount, long totalLoadTime, long evictionCount) Constructs a new `CacheStats` instance.

Method Summary

Modifier and Type	Method and Description
public double	averageLoadPenalty() Returns the average time spent loading new values.
public boolean	equals(Object the reference object with which to compare. object) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public long	evictionCount() Returns the number of times an entry has been evicted.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for the object.
public long	hitCount() Returns the number of times `Cache` lookup methods have returned a cached value.
public double	hitRate() Returns the ratio of cache requests which were hits.
public long	loadCount() Returns the total number of times that `Cache` lookup methods attempted to load new values.
public long	loadExceptionCount() Returns the number of times `Cache` lookup methods threw an exception while loading a new value.
public double	loadExceptionRate() Returns the ratio of cache loading attempts which threw exceptions.
public long	loadSuccessCount() Returns the number of times `Cache` lookup methods have successfully loaded a new value.
public CacheStats	minus(CacheStats other) Returns a new `CacheStats` representing the difference between this `CacheStats` and `other`.
public long	missCount() Returns the number of times `Cache` lookup methods have returned an uncached (newly loaded) value, or null.
public double	missRate() Returns the ratio of cache requests which were misses.
public CacheStats	plus(CacheStats other) Returns a new `CacheStats` representing the sum of this `CacheStats` and `other`.
public long	requestCount() Returns the number of times `Cache` lookup methods have returned either a cached or uncached value.
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.
public long	totalLoadTime() Returns the total number of nanoseconds the cache has spent loading new values.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

evictionCount	back to summary
private final long evictionCount

hitCount	back to summary
private final long hitCount

loadExceptionCount	back to summary
private final long loadExceptionCount

loadSuccessCount	back to summary
private final long loadSuccessCount

missCount	back to summary
private final long missCount

totalLoadTime	back to summary
private final long totalLoadTime Annotations @SuppressWarnings:GoodTime

CacheStats	back to summary
public CacheStats(long hitCount, long missCount, long loadSuccessCount, long loadExceptionCount, long totalLoadTime, long evictionCount) Constructs a new `CacheStats` instance. Five parameters of the same type in a row is a bad thing, but this class is not constructed by end users and is too fine-grained for a builder. Annotations @SuppressWarnings:GoodTime

Method Detail

averageLoadPenalty	back to summary
public double averageLoadPenalty() Returns the average time spent loading new values. This is defined as `totalLoadTime / (loadSuccessCount + loadExceptionCount)`. Note the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

equals back to summary

equals	back to summary
public boolean equals(Object object) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters object:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public boolean equals(Object object)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

object:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

evictionCount	back to summary
public long evictionCount() Returns the number of times an entry has been evicted. This count does not include manual invalidations.

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object.

Annotations

@Override

hitCount	back to summary
public long hitCount() Returns the number of times `Cache` lookup methods have returned a cached value.

hitRate	back to summary
public double hitRate() Returns the ratio of cache requests which were hits. This is defined as `hitCount / requestCount`, or `1.0` when `requestCount == 0`. Note that `hitRate + missRate =~ 1.0`.

loadCount back to summary

loadCount	back to summary
public long loadCount() Returns the total number of times that `Cache` lookup methods attempted to load new values. This includes both successful load operations and those that threw exceptions. This is defined as `loadSuccessCount + loadExceptionCount`. Note the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

public long loadCount()

Returns the total number of times that Cache lookup methods attempted to load new values. This includes both successful load operations and those that threw exceptions. This is defined as loadSuccessCount + loadExceptionCount.

Note

the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

loadExceptionCount back to summary

loadExceptionCount	back to summary
public long loadExceptionCount() Returns the number of times `Cache` lookup methods threw an exception while loading a new value. This is usually incremented in conjunction with `missCount`, though `missCount` is also incremented when cache loading completes successfully (see `loadSuccessCount`). Multiple concurrent misses for the same key will result in a single load operation. This may be incremented not in conjunction with `missCount` if the load occurs as a result of a refresh or if the cache loader returned more items than was requested. `missCount` may also be incremented not in conjunction with this (nor `loadSuccessCount`) on calls to `getIfPresent`.

public long loadExceptionCount()

Returns the number of times Cache lookup methods threw an exception while loading a new value. This is usually incremented in conjunction with missCount, though missCount is also incremented when cache loading completes successfully (see loadSuccessCount). Multiple concurrent misses for the same key will result in a single load operation. This may be incremented not in conjunction with missCount if the load occurs as a result of a refresh or if the cache loader returned more items than was requested. missCount may also be incremented not in conjunction with this (nor loadSuccessCount) on calls to getIfPresent.

loadExceptionRate back to summary

loadExceptionRate	back to summary
public double loadExceptionRate() Returns the ratio of cache loading attempts which threw exceptions. This is defined as `loadExceptionCount / (loadSuccessCount + loadExceptionCount)`, or `0.0` when `loadSuccessCount + loadExceptionCount == 0`. Note the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

public double loadExceptionRate()

Returns the ratio of cache loading attempts which threw exceptions. This is defined as loadExceptionCount / (loadSuccessCount + loadExceptionCount), or 0.0 when loadSuccessCount + loadExceptionCount == 0.

Note

the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

loadSuccessCount back to summary

loadSuccessCount	back to summary
public long loadSuccessCount() Returns the number of times `Cache` lookup methods have successfully loaded a new value. This is usually incremented in conjunction with `missCount`, though `missCount` is also incremented when an exception is encountered during cache loading (see `loadExceptionCount`). Multiple concurrent misses for the same key will result in a single load operation. This may be incremented not in conjunction with `missCount` if the load occurs as a result of a refresh or if the cache loader returned more items than was requested. `missCount` may also be incremented not in conjunction with this (nor `loadExceptionCount`) on calls to `getIfPresent`.

public long loadSuccessCount()

Returns the number of times Cache lookup methods have successfully loaded a new value. This is usually incremented in conjunction with missCount, though missCount is also incremented when an exception is encountered during cache loading (see loadExceptionCount). Multiple concurrent misses for the same key will result in a single load operation. This may be incremented not in conjunction with missCount if the load occurs as a result of a refresh or if the cache loader returned more items than was requested. missCount may also be incremented not in conjunction with this (nor loadExceptionCount) on calls to getIfPresent.

minus	back to summary
public CacheStats minus(CacheStats other) Returns a new `CacheStats` representing the difference between this `CacheStats` and `other`. Negative values, which aren't supported by `CacheStats` will be rounded up to zero.

missCount	back to summary
public long missCount() Returns the number of times `Cache` lookup methods have returned an uncached (newly loaded) value, or null. Multiple concurrent calls to `Cache` lookup methods on an absent value can result in multiple misses, all returning the results of a single cache load operation.

missRate back to summary

missRate	back to summary
public double missRate() Returns the ratio of cache requests which were misses. This is defined as `missCount / requestCount`, or `0.0` when `requestCount == 0`. Note that `hitRate + missRate =~ 1.0`. Cache misses include all requests which weren't cache hits, including requests which resulted in either successful or failed loading attempts, and requests which waited for other threads to finish loading. It is thus the case that `missCount >= loadSuccessCount + loadExceptionCount`. Multiple concurrent misses for the same key will result in a single load operation.

public double missRate()

Returns the ratio of cache requests which were misses. This is defined as missCount / requestCount, or 0.0 when requestCount == 0. Note that hitRate + missRate =~ 1.0. Cache misses include all requests which weren't cache hits, including requests which resulted in either successful or failed loading attempts, and requests which waited for other threads to finish loading. It is thus the case that missCount >= loadSuccessCount + loadExceptionCount. Multiple concurrent misses for the same key will result in a single load operation.

plus back to summary

plus	back to summary
public CacheStats plus(CacheStats other) Returns a new `CacheStats` representing the sum of this `CacheStats` and `other`. Note the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector. Since 11.0

public CacheStats plus(CacheStats other)

Returns a new CacheStats representing the sum of this CacheStats and other.

Note

the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

Since: 11.0

requestCount	back to summary
public long requestCount() Returns the number of times `Cache` lookup methods have returned either a cached or uncached value. This is defined as `hitCount + missCount`. Note the values of the metrics are undefined in case of overflow (though it is guaranteed not to throw an exception). If you require specific handling, we recommend implementing your own stats collector.

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Returns:String a string representation of the object. Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object.

Annotations

@Override

totalLoadTime back to summary

totalLoadTime	back to summary
public long totalLoadTime() Returns the total number of nanoseconds the cache has spent loading new values. This can be used to calculate the miss penalty. This value is increased every time `loadSuccessCount` or `loadExceptionCount` is incremented. Annotations @SuppressWarnings:GoodTime

public long totalLoadTime()

Returns the total number of nanoseconds the cache has spent loading new values. This can be used to calculate the miss penalty. This value is increased every time loadSuccessCount or loadExceptionCount is incremented.

Annotations

@SuppressWarnings:GoodTime

public final Class CacheStats

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail