org.apache.activemq.store.kahadb.disk.util

Class SequenceSet

java.lang.Object

org.apache.activemq.store.kahadb.disk.util.LinkedNodeList<Sequence>

org.apache.activemq.store.kahadb.disk.util.SequenceSet

All Implemented Interfaces:

Iterable<Long>

public class SequenceSet
extends LinkedNodeList<Sequence>
implements Iterable<Long>

Keeps track of a added long values. Collapses ranges of numbers using a Sequence representation. Use to keep track of received message ids to find out if a message is duplicate or if there are any missing messages.

Author:

chirino

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SequenceSet.Marshaller

Constructor Summary

Constructors

Constructor and Description
SequenceSet()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(long value)
void	add(Sequence value)
boolean	contains(int first, int last)
boolean	contains(long value) Returns true if the value given is contained within one of the sequences held in this set.
Sequence	get(int value)
List<Sequence>	getMissing(long first, long last)
List<Sequence>	getReceived()
Iterator<Long>	iterator()
long	rangeSize() Computes the size of this Sequence by summing the values of all the contained sequences.
boolean	remove(long value) Removes the given value from the Sequence set, splitting a contained sequence if necessary.
long	removeFirst() Removes and returns the first element from this list.
Sequence	removeFirstSequence(long count) Removes and returns the first sequence that is count range large.
Sequence	removeLastSequence() Removes and returns the last sequence from this list.

Methods inherited from class org.apache.activemq.store.kahadb.disk.util.LinkedNodeList

addFirst, addFirst, addLast, addLast, clear, getHead, getTail, isEmpty, reparent, rotate, rotateTo, size, toArrayList, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceSet

public SequenceSet()

Method Detail

add

public void add(Sequence value)

add

public boolean add(long value)

Parameters:

value - the value to add to the list

Returns:

false if the value was a duplicate.

remove

public boolean remove(long value)

Removes the given value from the Sequence set, splitting a contained sequence if necessary.

Parameters:

value - The value that should be removed from the SequenceSet.

Returns:

true if the value was removed from the set, false if there was no sequence in the set that contained the given value.

removeFirst

public long removeFirst()

Removes and returns the first element from this list.

Returns:

the first element from this list.

Throws:

NoSuchElementException - if this list is empty.

removeLastSequence

public Sequence removeLastSequence()

Removes and returns the last sequence from this list.

Returns:

the last sequence from this list or null if the list is empty.

removeFirstSequence

public Sequence removeFirstSequence(long count)

Removes and returns the first sequence that is count range large.

Returns:

a sequence that is count range large, or null if no sequence is that large in the list.

getMissing

public List<Sequence> getMissing(long first,
                        long last)

Returns:

all the id Sequences that are missing from this set that are not in between the range provided.

getReceived

public List<Sequence> getReceived()

Returns:

all the Sequence that are in this list

contains

public boolean contains(long value)

Returns true if the value given is contained within one of the sequences held in this set.

Parameters:

value - The value to search for in the set.

Returns:

true if the value is contained in the set.

contains

public boolean contains(int first,
               int last)

get

public Sequence get(int value)

rangeSize

public long rangeSize()

Computes the size of this Sequence by summing the values of all the contained sequences.

Returns:

the total number of values contained in this set if it were to be iterated over like an array.

iterator

public Iterator<Long> iterator()

Specified by:

iterator in interface Iterable<Long>