CSP for Java
(JCSP) 1.1-rc4

org.jcsp.util.ints
Class OverFlowingBufferInt

java.lang.Object
  extended by org.jcsp.util.ints.OverFlowingBufferInt
All Implemented Interfaces:
Serializable, Cloneable, ChannelDataStoreInt

public class OverFlowingBufferInt
extends Object
implements ChannelDataStoreInt, Serializable

This is used to create a buffered integer channel that always accepts input, discarding its last entered data if full.

Description

OverFlowingBufferInt is an implementation of ChannelDataStoreInt that yields a FIFO buffered semantics for a channel. When empty, the channel blocks readers. When full, a writer will be accepted but the written value overflows the buffer and is lost to the channel. See the static construction methods of Channel (Channel.one2oneInt(org.jcsp.util.ints.ChannelDataStoreInt) etc.).

The getState method returns EMPTY or NONEMPTYFULL, but never FULL.

Author:
P.D. Austin
See Also:
ZeroBufferInt, BufferInt, OverWriteOldestBufferInt, OverWritingBufferInt, InfiniteBufferInt, ChannelInt, Serialized Form

Field Summary
 
Fields inherited from interface org.jcsp.util.ints.ChannelDataStoreInt
EMPTY, FULL, NONEMPTYFULL
 
Constructor Summary
OverFlowingBufferInt(int size)
          Construct a new OverFlowingBufferInt with the specified size.
 
Method Summary
 Object clone()
          Returns a new (and EMPTY) OverFlowingBufferInt with the same creation parameters as this one.
 void endGet()
          Removes the oldest integer from the buffer.
 int get()
          Returns the oldest int from the OverFlowingBufferInt and removes it.
 int getState()
          Returns the current state of the OverFlowingBufferInt.
 void put(int value)
          Puts a new int into the OverFlowingBufferInt.
 void removeAll()
           
 int startGet()
          Returns the oldest integer 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 Detail

OverFlowingBufferInt

public OverFlowingBufferInt(int size)
Construct a new OverFlowingBufferInt with the specified size.

Parameters:
size - the number of ints the OverFlowingBufferInt can store.
Throws:
BufferIntSizeError - if size is zero or negative. Note: no action should be taken to try/catch this exception - application code generating it is in error and needs correcting.
Method Detail

get

public int get()
Returns the oldest int from the OverFlowingBufferInt and removes it.

Pre-condition: getState must not currently return EMPTY.

Specified by:
get in interface ChannelDataStoreInt
Returns:
the oldest int from the OverFlowingBufferInt

startGet

public int startGet()
Returns the oldest integer from the buffer but does not remove it. Pre-condition: getState must not currently return EMPTY.

Specified by:
startGet in interface ChannelDataStoreInt
Returns:
the oldest int from the Buffer
See Also:
ChannelDataStoreInt.endGet()

endGet

public void endGet()
Removes the oldest integer from the buffer.

Specified by:
endGet in interface ChannelDataStoreInt
See Also:
ChannelDataStoreInt.startGet()

put

public void put(int value)
Puts a new int into the OverFlowingBufferInt.

If OverFlowingBufferInt is full, the item is discarded.

Specified by:
put in interface ChannelDataStoreInt
Parameters:
value - the int to put into the OverFlowingBufferInt

getState

public int getState()
Returns the current state of the OverFlowingBufferInt.

Specified by:
getState in interface ChannelDataStoreInt
Returns:
the current state of the OverFlowingBufferInt (EMPTY or NONEMPTYFULL)

clone

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

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

Specified by:
clone in interface ChannelDataStoreInt
Overrides:
clone in class Object
Returns:
the cloned instance of this OverFlowingBufferInt.

removeAll

public void removeAll()
Specified by:
removeAll in interface ChannelDataStoreInt

CSP for Java
(JCSP) 1.1-rc4

Submit a bug or feature to jcsp-team@kent.ac.uk
Version 1.1-rc4 of the JCSP API Specification (Copyright 1997-2008 P.D.Austin and P.H.Welch - All Rights Reserved)
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