Package org.wso2.carbon.logging.appender.http.utils.queue

Class PersistentQueue<T extends Serializable>

java.lang.Object
org.wso2.carbon.logging.appender.http.utils.queue.PersistentQueue<T>
Type Parameters:
T - type of the object to be stored in the queue.
All Implemented Interfaces:
AutoCloseable
public class PersistentQueue<T extends Serializable> extends Object implements AutoCloseable
This class implements a file based queue which can be used to store objects in serialized form in a persistent manner and consumed later.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PersistentQueue(String queueDirectoryPath, long maxDiskSpaceInBytes, long maxBatchSizeInBytes)
    Constructor of the PersistentQueue class.

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    calculateDiskUsage()
    Loops through each file in the queue directory and calculates the disk usage of the queue.
    void
    close()
    Closes the queue.
    T
    dequeue()
    Dequeues the next object from the queue.
    void
    enqueue(T object)
    Enqueues the given object to the queue.
    float
    getUsedSpaceFraction()
    Returns the fraction of the disk space used by the queue.
    boolean
    isEmpty()
    Checks if the queue is empty.
    boolean
    isFull()
    Checks if the queue is full.
    T
    peek()
    Peeks the next object from the queue without removing it.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • PersistentQueue

      public PersistentQueue(String queueDirectoryPath, long maxDiskSpaceInBytes, long maxBatchSizeInBytes) throws PersistentQueueException
      Constructor of the PersistentQueue class.
      Parameters:
      queueDirectoryPath - path of the queue directory.
      maxDiskSpaceInBytes - maximum disk space that can be used by the queue.
      maxBatchSizeInBytes - maximum size of a single queue block.
      Throws:
      PersistentQueueException - if an error occurs while creating the queue.

  • Method Details

    • enqueue

      public void enqueue(T object) throws PersistentQueueException
      Enqueues the given object to the queue.
      Parameters:
      object - object to be enqueued.
      Throws:
      PersistentQueueException - if an error occurs while enqueuing the object.

    • dequeue

      public T dequeue() throws PersistentQueueException
      Dequeues the next object from the queue.
      Returns:
      dequeued object.
      Throws:
      PersistentQueueException - if an error occurs while dequeue the object.

    • peek

      public T peek() throws PersistentQueueException
      Peeks the next object from the queue without removing it.
      Returns:
      peeked object.
      Throws:
      PersistentQueueException - if an error occurs while peeking the object.

    • isEmpty

      public boolean isEmpty()
      Checks if the queue is empty.
      Returns:
      boolean if the queue is empty.

    • isFull

      public boolean isFull()
      Checks if the queue is full.
      Returns:
      boolean if the queue is full.

    • calculateDiskUsage

      public long calculateDiskUsage() throws PersistentQueueException
      Loops through each file in the queue directory and calculates the disk usage of the queue.
      Returns:
      disk usage of the queue.
      Throws:
      PersistentQueueException - if an error occurs while calculating the disk usage.

    • getUsedSpaceFraction

      public float getUsedSpaceFraction()
      Returns the fraction of the disk space used by the queue.
      Returns:
      fraction of the disk space used by the queue.

    • close

      public void close() throws PersistentQueueException
      Closes the queue.
      Specified by:
      close in interface AutoCloseable
      Throws:
      PersistentQueueException - if an error occurs while closing the queue.