Class CyclicBuffer

java.lang.Object
org.apache.log4j.helpers.CyclicBuffer

public class CyclicBuffer extends Object
CyclicBuffer is used by other appenders to hold LoggingEvents for immediate or differed display.

This buffer gives read access to any element in the buffer not just the first or last element.

Since:
0.9.0
Author:
Ceki Gülcü
  • Constructor Details

    • CyclicBuffer

      public CyclicBuffer(int maxSize) throws IllegalArgumentException
      Instantiate a new CyclicBuffer of at most maxSize events. The maxSize argument must a positive integer.
      Parameters:
      maxSize - The maximum number of elements in the buffer.
      Throws:
      IllegalArgumentException
  • Method Details

    • add

      public void add(LoggingEvent event)
      Add an event as the last event in the buffer.
    • get

      public LoggingEvent get(int i)
      Get the ith oldest event currently in the buffer. If i is outside the range 0 to the number of elements currently in the buffer, then null is returned.
    • getMaxSize

      public int getMaxSize()
    • get

      public LoggingEvent get()
      Get the oldest (first) element in the buffer. The oldest element is removed from the buffer.
    • length

      public int length()
      Get the number of elements in the buffer. This number is guaranteed to be in the range 0 to maxSize (inclusive).
    • resize

      public void resize(int newSize)
      Resize the cyclic buffer to newSize.
      Throws:
      IllegalArgumentException - if newSize is negative.