Package org.terracotta.statistics

Class ValueStatistics

java.lang.Object

org.terracotta.statistics.ValueStatistics

public class ValueStatistics
extends java.lang.Object

Constructor Summary

Constructors

Constructor	Description
ValueStatistics()

Method Summary

Modifier and Type	Method	Description
static <T extends java.io.Serializable> ConstantValueStatistic<T>	constant(StatisticType type, T value)
static <T extends java.lang.Number> ValueStatistic<T>	counter(java.util.function.Supplier<T> supplier)
static <T extends java.lang.Number> ValueStatistic<T>	gauge(java.util.function.Supplier<T> supplier)
static <T extends java.io.Serializable> ValueStatistic<T>	memoize(long delay, java.util.concurrent.TimeUnit unit, ValueStatistic<T> valueStatistic)	Returns a ValueStatistic that caches the value of a statistic for at least a specific amount of time.
static <T extends java.io.Serializable> ConstantValueStatistic<T>	nullValue(StatisticType type)
static <T extends java.lang.Number> ValueStatistic<T>	rate(java.util.function.Supplier<T> supplier)
static <T extends java.lang.Number> ValueStatistic<T>	ratio(java.util.function.Supplier<T> supplier)
static <T extends java.io.Serializable> ValueStatistic<T>	supply(StatisticType type, java.util.function.Supplier<T> supplier)
static <T extends Table> ValueStatistic<T>	table(java.util.function.Supplier<T> supplier)

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueStatistics

public ValueStatistics()

Method Detail

nullValue

public static <T extends java.io.Serializable> ConstantValueStatistic<T> nullValue(StatisticType type)

constant

public static <T extends java.io.Serializable> ConstantValueStatistic<T> constant(StatisticType type,
                                                                                  T value)

supply

public static <T extends java.io.Serializable> ValueStatistic<T> supply(StatisticType type,
                                                                        java.util.function.Supplier<T> supplier)

gauge

public static <T extends java.lang.Number> ValueStatistic<T> gauge(java.util.function.Supplier<T> supplier)

counter

public static <T extends java.lang.Number> ValueStatistic<T> counter(java.util.function.Supplier<T> supplier)

rate

public static <T extends java.lang.Number> ValueStatistic<T> rate(java.util.function.Supplier<T> supplier)

ratio

public static <T extends java.lang.Number> ValueStatistic<T> ratio(java.util.function.Supplier<T> supplier)

table

public static <T extends Table> ValueStatistic<T> table(java.util.function.Supplier<T> supplier)

memoize

public static <T extends java.io.Serializable> ValueStatistic<T> memoize(long delay,
                                                                         java.util.concurrent.TimeUnit unit,
                                                                         ValueStatistic<T> valueStatistic)

Returns a ValueStatistic that caches the value of a statistic for at least a specific amount of time.

This method does not block.

When the delay expires, if several threads are coming at the same time to read the expired value, then only one will do the update and set a new expiring delay and read the new value. The other threads can continue to read the current expired value for their next call until it gets updated.

If the caching delay is smaller than the time it takes for a statistic value to be computed, then it is possible that a new thread starts asking for a new value before the previous update is completed. In this case, there is no guarantee that the cached value will be updated in order because it depends on the time took to get the new value.

Type Parameters:

T - The statistic type

Parameters:

delay - The delay

unit - The unit of time

valueStatistic - The delegate statistic that will provide the value

Returns:

the memoizing statistic