ValueWatcher (Starjava UTIL API)

java.lang.Object

uk.ac.starlink.util.ValueWatcher

public class ValueWatcher extends Object

Looks out for an unused value in a sequence of submitted numbers. This can be used to identify a suitable 'magic' representation for a bad value.

Since:: 22 Jun 2006
Author:: Mark Taylor

Constructor Summary

Constructors

Constructor

Description

ValueWatcher(long loBound, long hiBound)

Constructs a ValueWatcher which will look out for values in the range covered by loBound and hiBound inclusive.
Method Summary

Modifier and Type

Method

Description

Long

getUnused()

Returns a value in the range loBound..hiBound which has never been sumitted to useValue(long).

void

useValue(long val)

Takes note of a value.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- ValueWatcher
  
  public ValueWatcher(long loBound, long hiBound)
  
  Constructs a ValueWatcher which will look out for values in the range covered by loBound and hiBound inclusive. These shouldn't be arbitrarily far apart - storage of up to about one bit per value in the range will be required.
  
  Parameters:
  
  loBound - lower bound to watch for (inclusive)
  
  hiBound - upper bound to watch for (inclusive)
Method Details
- useValue
  
  public void useValue(long val)
  
  Takes note of a value. val will never subsequently be returned from getUnused().
  
  Parameters:
  
  val - value to note
- getUnused
  
  public Long getUnused()
  
  Returns a value in the range loBound..hiBound which has never been sumitted to useValue(long). If there is no such value, returns null.
  
  Returns:
  
  unused value in range