Package org.jcsp.util

Class Buffer

java.lang.Object
org.jcsp.util.Buffer
All Implemented Interfaces:
Serializable, Cloneable, ChannelDataStore
public class Buffer extends Object implements ChannelDataStore, Serializable
This is used to create a buffered object channel that never loses data.

Description

Buffer is an implementation of ChannelDataStore that yields a blocking FIFO buffered semantics for a channel. See the static construction methods of Channel (Channel.one2one(org.jcsp.util.ChannelDataStore) etc.).

The getState method returns EMPTY, NONEMPTYFULL or FULL according to the state of the buffer.

Author:
P.D. Austin
See Also:

  • Field Summary

    Fields inherited from interface org.jcsp.util.ChannelDataStore

    EMPTY, FULL, NONEMPTYFULL

  • Constructor Summary

    Constructors
    Constructor
    Description
    Buffer(int size)
    Construct a new Buffer with the specified size.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    clone()
    Returns a new (and EMPTY) Buffer with the same creation parameters as this one.
    void
    endGet()
    Removes the oldest object from the buffer.
    Object
    get()
    Returns the oldest Object from the Buffer and removes it.
    int
    getState()
    Returns the current state of the Buffer.
    void
    put(Object value)
    Puts a new Object into the Buffer.
    void
    removeAll()
    Deletes all items in the buffer, leaving it empty.
    Object
    startGet()
    Returns the oldest object from the buffer but does not remove it.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Buffer

      public Buffer(int size)
      Construct a new Buffer with the specified size.
      Parameters:
      size - the number of Objects the Buffer can store.
      Throws:
      BufferSizeError - if size is negative. Note: no action should be taken to try/catch this exception - application code generating it is in error and needs correcting.

  • Method Details

    • get

      public Object get()
      Returns the oldest Object from the Buffer and removes it.

      Pre-condition: getState must not currently return EMPTY.

      Specified by:
      get in interface ChannelDataStore
      Returns:
      the oldest Object from the Buffer

    • startGet

      public Object startGet()
      Returns the oldest object from the buffer but does not remove it. Pre-condition: getState must not currently return EMPTY.
      Specified by:
      startGet in interface ChannelDataStore
      Returns:
      the oldest Object from the Buffer
      See Also:

    • endGet

      public void endGet()
      Removes the oldest object from the buffer.
      Specified by:
      endGet in interface ChannelDataStore
      See Also:

    • put

      public void put(Object value)
      Puts a new Object into the Buffer.

      Pre-condition: getState must not currently return FULL.

      Specified by:
      put in interface ChannelDataStore
      Parameters:
      value - the Object to put into the Buffer

    • getState

      public int getState()
      Returns the current state of the Buffer.
      Specified by:
      getState in interface ChannelDataStore
      Returns:
      the current state of the Buffer (EMPTY, NONEMPTYFULL or FULL)

    • clone

      public Object clone()
      Returns a new (and EMPTY) Buffer with the same creation parameters as this one.

      Note: Only the size and structure of the Buffer is cloned, not any stored data.

      Specified by:
      clone in interface ChannelDataStore
      Overrides:
      clone in class Object
      Returns:
      the cloned instance of this Buffer

    • removeAll

      public void removeAll()
      Description copied from interface: ChannelDataStore
      Deletes all items in the buffer, leaving it empty.
      Specified by:
      removeAll in interface ChannelDataStore