java.lang.Object
- com.github.benmanes.caffeine.cache.stats.CacheStats

```
@Immutable
public final class CacheStats
extends Object
```
Statistics about the performance of a Cache.
Cache statistics are incremented according to the following rules:
- When a cache lookup encounters an existing cache entry hitCount is incremented.
- When a cache lookup first encounters a missing cache entry, a new entry is loaded.
  - After successfully loading an entry missCount and loadSuccessCount are incremented, and the total loading time, in nanoseconds, is added to totalLoadTime.
  - When an exception is thrown while loading an entry or if the loaded value is {code null}, missCount and loadFailureCount are incremented, and the total loading time, in nanoseconds, is added to totalLoadTime.
  - Cache lookups that encounter a missing cache entry that is still loading will wait for loading to complete (whether successful or not) and then increment missCount.
- When an entry is computed through the asMap the loadSuccessCount or loadFailureCount is incremented.
- When an entry is evicted from the cache, evictionCount is incremented and the weight added to evictionWeight.
- No stats are modified when a cache entry is invalidated or manually removed.
- No stats are modified by non-computing operations invoked on the asMap view of the cache.
A lookup is specifically defined as an invocation of one of the methods LoadingCache.get(Object), Cache.get(Object, java.util.function.Function), or LoadingCache.getAll(Iterable).
This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of CacheStats may have unpredictable results and should be avoided.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`@org.checkerframework.checker.index.qual.NonNegative double`	`averageLoadPenalty()`	Returns the average number of nanoseconds spent loading new values.
`static CacheStats`	`empty()`	Returns a statistics instance where no cache events have been recorded.
`boolean`	`equals(@Nullable Object o)`
`@org.checkerframework.checker.index.qual.NonNegative long`	`evictionCount()`	Returns the number of times an entry has been evicted.
`@org.checkerframework.checker.index.qual.NonNegative long`	`evictionWeight()`	Returns the sum of weights of evicted entries.
`int`	`hashCode()`
`@org.checkerframework.checker.index.qual.NonNegative long`	`hitCount()`	Returns the number of times `Cache` lookup methods have returned a cached value.
`@org.checkerframework.checker.index.qual.NonNegative double`	`hitRate()`	Returns the ratio of cache requests which were hits.
`@org.checkerframework.checker.index.qual.NonNegative long`	`loadCount()`	Returns the total number of times that `Cache` lookup methods attempted to load new values.
`@org.checkerframework.checker.index.qual.NonNegative long`	`loadFailureCount()`	Returns the number of times `Cache` lookup methods failed to load a new value, either because no value was found or an exception was thrown while loading.
`@org.checkerframework.checker.index.qual.NonNegative double`	`loadFailureRate()`	Returns the ratio of cache loading attempts which threw exceptions.
`@org.checkerframework.checker.index.qual.NonNegative long`	`loadSuccessCount()`	Returns the number of times `Cache` lookup methods have successfully loaded a new value.
`CacheStats`	`minus(CacheStats other)`	Returns a new `CacheStats` representing the difference between this `CacheStats` and `other`.
`@org.checkerframework.checker.index.qual.NonNegative long`	`missCount()`	Returns the number of times `Cache` lookup methods have returned an uncached (newly loaded) value, or null.
`@org.checkerframework.checker.index.qual.NonNegative double`	`missRate()`	Returns the ratio of cache requests which were misses.
`static CacheStats`	of(@org.checkerframework.checker.index.qual.NonNegative long hitCount, @org.checkerframework.checker.index.qual.NonNegative long missCount, @org.checkerframework.checker.index.qual.NonNegative long loadSuccessCount, @org.checkerframework.checker.index.qual.NonNegative long loadFailureCount, @org.checkerframework.checker.index.qual.NonNegative long totalLoadTime, @org.checkerframework.checker.index.qual.NonNegative long evictionCount, @org.checkerframework.checker.index.qual.NonNegative long evictionWeight)	Returns a `CacheStats` representing the specified statistics.
`CacheStats`	`plus(CacheStats other)`	Returns a new `CacheStats` representing the sum of this `CacheStats` and `other`.
`@org.checkerframework.checker.index.qual.NonNegative long`	`requestCount()`	Returns the number of times `Cache` lookup methods have returned either a cached or uncached value.
`String`	`toString()`
`@org.checkerframework.checker.index.qual.NonNegative long`	`totalLoadTime()`	Returns the total number of nanoseconds the cache has spent loading new values.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Method Detail
  - of
```
public static CacheStats of(@org.checkerframework.checker.index.qual.NonNegative long hitCount,
                            @org.checkerframework.checker.index.qual.NonNegative long missCount,
                            @org.checkerframework.checker.index.qual.NonNegative long loadSuccessCount,
                            @org.checkerframework.checker.index.qual.NonNegative long loadFailureCount,
                            @org.checkerframework.checker.index.qual.NonNegative long totalLoadTime,
                            @org.checkerframework.checker.index.qual.NonNegative long evictionCount,
                            @org.checkerframework.checker.index.qual.NonNegative long evictionWeight)
```
    Returns a CacheStats representing the specified statistics.
    
    Parameters:
    
    hitCount - the number of cache hits
    
    missCount - the number of cache misses
    
    loadSuccessCount - the number of successful cache loads
    
    loadFailureCount - the number of failed cache loads
    
    totalLoadTime - the total load time (success and failure)
    
    evictionCount - the number of entries evicted from the cache
    
    evictionWeight - the sum of weights of entries evicted from the cache
    
    Returns:
    
    a CacheStats representing the specified statistics
  - empty
```
public static CacheStats empty()
```
    Returns a statistics instance where no cache events have been recorded.
    
    Returns:
    
    an empty statistics instance
  - requestCount
```
public @org.checkerframework.checker.index.qual.NonNegative 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.
    
    Returns:
    
    the hitCount + missCount
  - hitCount
```
public @org.checkerframework.checker.index.qual.NonNegative long hitCount()
```
    Returns the number of times Cache lookup methods have returned a cached value.
    
    Returns:
    
    the number of times Cache lookup methods have returned a cached value
  - hitRate
```
public @org.checkerframework.checker.index.qual.NonNegative 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.
    
    Returns:
    
    the ratio of cache requests which were hits
  - missCount
```
public @org.checkerframework.checker.index.qual.NonNegative 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.
    
    Returns:
    
    the number of times Cache lookup methods have returned an uncached (newly loaded) value, or null
  - missRate
```
public @org.checkerframework.checker.index.qual.NonNegative 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 + loadFailureCount. Multiple concurrent misses for the same key will result in a single load operation.
    
    Returns:
    
    the ratio of cache requests which were misses
  - loadCount
```
public @org.checkerframework.checker.index.qual.NonNegative long loadCount()
```
    Returns the total number of times that Cache lookup methods attempted to load new values. This includes both successful load operations, as well as those that threw exceptions. This is defined as loadSuccessCount + loadFailureCount.
    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.
    
    Returns:
    
    the loadSuccessCount + loadFailureCount
  - loadSuccessCount
```
public @org.checkerframework.checker.index.qual.NonNegative long loadSuccessCount()
```
    Returns the number of times Cache lookup methods have successfully loaded a new value. This is always incremented in conjunction with missCount, though missCount is also incremented when an exception is encountered during cache loading (see loadFailureCount). Multiple concurrent misses for the same key will result in a single load operation.
    
    Returns:
    
    the number of times Cache lookup methods have successfully loaded a new value
  - loadFailureCount
```
public @org.checkerframework.checker.index.qual.NonNegative long loadFailureCount()
```
    Returns the number of times Cache lookup methods failed to load a new value, either because no value was found or an exception was thrown while loading. This is always 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.
    
    Returns:
    
    the number of times Cache lookup methods failed to load a new value
  - loadFailureRate
```
public @org.checkerframework.checker.index.qual.NonNegative double loadFailureRate()
```
    Returns the ratio of cache loading attempts which threw exceptions. This is defined as loadFailureCount / (loadSuccessCount + loadFailureCount), or 0.0 when loadSuccessCount + loadFailureCount == 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.
    
    Returns:
    
    the ratio of cache loading attempts which threw exceptions
  - totalLoadTime
```
public @org.checkerframework.checker.index.qual.NonNegative 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 loadFailureCount is incremented.
    
    Returns:
    
    the total number of nanoseconds the cache has spent loading new values
  - averageLoadPenalty
```
public @org.checkerframework.checker.index.qual.NonNegative double averageLoadPenalty()
```
    Returns the average number of nanoseconds spent loading new values. This is defined as totalLoadTime / (loadSuccessCount + loadFailureCount).
    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.
    
    Returns:
    
    the average number of nanoseconds spent loading new values
  - evictionCount
```
public @org.checkerframework.checker.index.qual.NonNegative long evictionCount()
```
    Returns the number of times an entry has been evicted. This count does not include manual invalidations.
    
    Returns:
    
    the number of times an entry has been evicted
  - evictionWeight
```
public @org.checkerframework.checker.index.qual.NonNegative long evictionWeight()
```
    Returns the sum of weights of evicted entries. This total does not include manual invalidations.
    
    Returns:
    
    the sum of weights of evicted entities
  - minus
```
@CheckReturnValue
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.
    
    Parameters:
    
    other - the statistics to subtract with
    
    Returns:
    
    the difference between this instance and other
  - plus
```
@CheckReturnValue
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.
    
    Parameters:
    
    other - the statistics to add with
    
    Returns:
    
    the sum of the statistics
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(@Nullable Object o)
```
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class CacheStats

Method Summary

Methods inherited from class java.lang.Object

Method Detail

of

empty

requestCount

hitCount

hitRate

missCount

missRate

loadCount

loadSuccessCount

loadFailureCount

loadFailureRate

totalLoadTime

averageLoadPenalty

evictionCount

evictionWeight

minus

plus

hashCode

equals

toString