Package org.deckfour.xes.model.buffered

Class XFastEventList

java.lang.Object

org.deckfour.xes.model.buffered.XFastEventList

All Implemented Interfaces:

java.lang.Cloneable

public class XFastEventList
extends java.lang.Object
implements java.lang.Cloneable

Implements a fast list of events stored in disk buffers, by using the means of the NikeFS2 virtual file system for event logs. Frees main memory for other tasks, while guaranteeing quick sequential and random access to event log data.

Author:

Christian W. Guenther (christian@deckfour.org)

Field Summary

Fields

Modifier and Type	Field	Description
protected XAttributeMapSerializer	attributeMapSerializer	Attribute map serializer.
protected XSequentialEventBuffer	buffer	Sequential event buffer used for raw buffered storage.
protected java.util.BitSet	holeFlags	Indicates the positions in the list which are no longer valid, i.e.
static int	OVERFLOW_LIMIT	Maximal number of buffered edit operations on the list, before it is consolidated to the disk buffer.
protected XEvent[]	overflowEntries	Array of additional overflow entries.
protected int[]	overflowIndices	Array of list indices for additional overflow entries.
protected int	overflowSize	Current, actual size of the overflow data structures.
protected int	size	Size of the list.

Constructor Summary

Constructors

Constructor	Description
XFastEventList(XAttributeMapSerializer attributeMapSerializer)	Creates a new fast event list.

Method Summary

Modifier and Type	Method	Description
int	append(XEvent event)	Appends the given event to the end of this fast event list.
void	cleanup()	Cleans up this fast event list after use, frees all associated resources.
java.lang.Object	clone()	Creates a clone of this list.
boolean	consolidate()	Consolidates this fast event list.
protected void	finalize()
XEvent	get(int index)	Retrieves an event at a specific index in the list.
void	insert(XEvent event, int index)	Inserts an event at a given index into the list.
int	insertOrdered(XEvent event)	Inserts the given event at its logical position in the list.
boolean	isTainted()	Checks whether this list needs consolidation, i.e.
XEvent	remove(int index)	Removes the event at the given index from this list.
XEvent	replace(XEvent event, int index)	Replaces the event at the given index with another event.
int	size()	Returns the size of this event list.

Methods inherited from class java.lang.Object

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

Field Detail

OVERFLOW_LIMIT

public static int OVERFLOW_LIMIT

Maximal number of buffered edit operations on the list, before it is consolidated to the disk buffer.

size

protected int size

Size of the list.

buffer

protected XSequentialEventBuffer buffer

Sequential event buffer used for raw buffered storage.

attributeMapSerializer

protected XAttributeMapSerializer attributeMapSerializer

Attribute map serializer.

holeFlags

protected java.util.BitSet holeFlags

Indicates the positions in the list which are no longer valid, i.e. need to be skipped.

overflowIndices

protected int[] overflowIndices

Array of list indices for additional overflow entries.

overflowEntries

protected XEvent[] overflowEntries

Array of additional overflow entries.

overflowSize

protected int overflowSize

Current, actual size of the overflow data structures.

Constructor Detail

XFastEventList

public XFastEventList(XAttributeMapSerializer attributeMapSerializer)
               throws java.io.IOException

Creates a new fast event list.

Parameters:

attributeMapSerializer - The attribute map serializer to be used.

Throws:

java.io.IOException

Method Detail

append

public int append(XEvent event)
           throws java.io.IOException

Appends the given event to the end of this fast event list.

Parameters:

event - Event to be added.

Returns:

Index of the added event.

Throws:

java.io.IOException

cleanup

public void cleanup()
             throws java.io.IOException

Cleans up this fast event list after use, frees all associated resources.

Throws:

java.io.IOException

consolidate

public boolean consolidate()
                    throws java.io.IOException

Consolidates this fast event list. Consolidation implies, that all overflow and skipping data structures are freed, and the buffered representation is brought completely in-line with the virtual current contents of the list. The actual consolidation will be skipped, if no need for it is detected by the algorithm.

Returns:

Whether consolidation has been performed.

Throws:

java.io.IOException

get

public XEvent get(int index)
           throws java.lang.IndexOutOfBoundsException,
                  java.io.IOException

Retrieves an event at a specific index in the list.

Parameters:

index - Index of the required event in the list.

Returns:

The requested event.

Throws:

java.lang.IndexOutOfBoundsException

java.io.IOException

insert

public void insert(XEvent event,
                   int index)
            throws java.lang.IndexOutOfBoundsException,
                   java.io.IOException

Inserts an event at a given index into the list.

Parameters:

event - The event to be inserted.

index - Requested index of the inserted event.

Throws:

java.lang.IndexOutOfBoundsException

java.io.IOException

insertOrdered

public int insertOrdered(XEvent event)
                  throws java.io.IOException

Inserts the given event at its logical position in the list. The logical position is determined from timestamp information, if available. Otherwise, the event is appended to the end of the list.

Parameters:

event - Event to be inserted.

Returns:

Position of the event after insertion.

Throws:

java.io.IOException

isTainted

public boolean isTainted()

Checks whether this list needs consolidation, i.e. whether the overflow and skipping structures have any content.

Returns:

Whether this list is tainted.

remove

public XEvent remove(int index)
              throws java.lang.IndexOutOfBoundsException,
                     java.io.IOException

Removes the event at the given index from this list.

Parameters:

index - Index of the event to be removed.

Returns:

The removed event.

Throws:

java.lang.IndexOutOfBoundsException

java.io.IOException

replace

public XEvent replace(XEvent event,
                      int index)
               throws java.lang.IndexOutOfBoundsException,
                      java.io.IOException

Replaces the event at the given index with another event.

Parameters:

event - Event to be inserted at the given position.

index - Position to replace event at.

Returns:

The removed event, which has been replaced.

Throws:

java.lang.IndexOutOfBoundsException

java.io.IOException

size

public int size()

Returns the size of this event list.

Returns:

The number of currently contained events.

clone

public java.lang.Object clone()

Creates a clone of this list.

Overrides:

clone in class java.lang.Object

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable