Package org.apache.lucene.store

# Class RateLimiter

java.lang.Object
org.apache.lucene.store.RateLimiter

Direct Known Subclasses:
  `MergeRateLimiter`, `RateLimiter.SimpleRateLimiter`

public abstract class RateLimiter extends Object
Abstract base class to rate limit IO. Typically implementations are shared across multiple IndexInputs or IndexOutputs (for example those involved all merging). Those IndexInputs and IndexOutputs would call `pause(long)` whenever the have read or written more than `getMinPauseCheckBytes()` bytes.

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static class`
  `RateLimiter.SimpleRateLimiter`
  Simple class to rate limit IO.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RateLimiter()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `abstract double`
  `getMBPerSec()`
  The current MB per second rate limit.
  `abstract long`
  `getMinPauseCheckBytes()`
  How many bytes caller should add up itself before invoking `pause(long)`.
  `abstract long`
  `pause(long bytes)`
  Pauses, if necessary, to keep the instantaneous IO rate at or below the target.
  `abstract void`
  `setMBPerSec(double mbPerSec)`
  Sets an updated MB per second rate limit.

  ### Methods inherited from class java.lang.Object

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

- ## Constructor Details

  - ### RateLimiter

    public RateLimiter()

- ## Method Details

  - ### setMBPerSec

    public abstract void setMBPerSec(double mbPerSec)
    Sets an updated MB per second rate limit. A subclass is allowed to perform dynamic updates of the rate limit during use.

  - ### getMBPerSec

    public abstract double getMBPerSec()
    The current MB per second rate limit.

  - ### pause

    public abstract long pause(long bytes) throws IOException
    Pauses, if necessary, to keep the instantaneous IO rate at or below the target.

    Note: the implementation is thread-safe

    Returns:
      the pause time in nano seconds
    Throws:
      `IOException`

  - ### getMinPauseCheckBytes

    public abstract long getMinPauseCheckBytes()
    How many bytes caller should add up itself before invoking `pause(long)`. NOTE: The value returned by this method may change over time and is not guaranteed to be constant throughout the lifetime of the RateLimiter. Users are advised to refresh their local values with calls to this method to ensure consistency.