Package org.jcsp.util
Class Buffer<T>
java.lang.Object
org.jcsp.util.Buffer<T>
- All Implemented Interfaces:
Serializable
,Cloneable
,ChannelDataStore<T>
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 ofChannel
(Channel.one2one(org.jcsp.util.ChannelDataStore)
etc.).
The getState method returns EMPTY, NONEMPTYFULL or FULL according to the state of the buffer.
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final T[]
The storage for the buffered Objectsprivate int
The number of Objects stored in the Bufferprivate int
The index of the oldest element (when counter > 0)private int
The index of the next free element (when counter < buffer.length)Fields inherited from interface org.jcsp.util.ChannelDataStore
EMPTY, FULL, NONEMPTYFULL
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionclone()
Returns a new (and EMPTY) Buffer with the same creation parameters as this one.void
endGet()
Removes the oldest object from the buffer.get()
Returns the oldest Object from the Buffer and removes it.int
getState()
Returns the current state of the Buffer.void
Puts a new Object into the Buffer.void
Deletes all items in the buffer, leaving it empty.startGet()
Returns the oldest object from the buffer but does not remove it.
-
Field Details
-
buffer
The storage for the buffered Objects -
counter
private int counterThe number of Objects stored in the Buffer -
firstIndex
private int firstIndexThe index of the oldest element (when counter > 0) -
lastIndex
private int lastIndexThe index of the next free element (when counter < buffer.length)
-
-
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
Returns the oldest Object from the Buffer and removes it.Pre-condition: getState must not currently return EMPTY.
- Specified by:
get
in interfaceChannelDataStore<T>
- Returns:
- the oldest Object from the Buffer
-
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 interfaceChannelDataStore<T>
- Returns:
- the oldest Object from the Buffer
- See Also:
-
endGet
public void endGet()Removes the oldest object from the buffer.- Specified by:
endGet
in interfaceChannelDataStore<T>
- See Also:
-
put
Puts a new Object into the Buffer.Pre-condition: getState must not currently return FULL.
- Specified by:
put
in interfaceChannelDataStore<T>
- Parameters:
value
- the Object to put into the Buffer
-
getState
public int getState()Returns the current state of the Buffer.- Specified by:
getState
in interfaceChannelDataStore<T>
- Returns:
- the current state of the Buffer (EMPTY, NONEMPTYFULL or FULL)
-
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 interfaceChannelDataStore<T>
- Overrides:
clone
in classObject
- 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 interfaceChannelDataStore<T>
-