com.marklogic.hub.util

Class DiskQueue<E extends java.io.Serializable>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<java.lang.String>

com.marklogic.hub.util.DiskQueue<E>

Type Parameters:

E - - A Serializable Class

All Implemented Interfaces:

java.lang.AutoCloseable, java.lang.Iterable<java.lang.String>, java.util.Collection<java.lang.String>, java.util.Queue<java.lang.String>

public class DiskQueue<E extends java.io.Serializable>
extends java.util.AbstractQueue<java.lang.String>
implements java.lang.AutoCloseable

A queue that writes extra elements to disk, and reads them in as needed. This implementation is optimized for being filled once (ie by the iterator in a reducer) and then incrementally read. So it wouldn't work very well if reads/writes were happening simultaneously, once anything had spilled to disk.

Constructor Summary

Constructors

Constructor and Description
DiskQueue(int maxInMemorySize) Construct a disk-backed queue that keeps at most maxInMemorySize elements in memory.
DiskQueue(int maxInMemorySize, java.io.File tempDir) Construct a disk-backed queue that keeps at most maxInMemorySize elements in memory.

Method Summary

Modifier and Type	Method and Description
void	clear()
void	close()
java.util.Iterator<java.lang.String>	iterator()
boolean	offer(java.lang.String element)
java.lang.String	peek()
java.lang.String	poll()
java.lang.String	remove()
int	size()

Methods inherited from class java.util.AbstractQueue

add, addAll, element

Methods inherited from class java.util.AbstractCollection

contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

contains, containsAll, equals, hashCode, isEmpty, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

DiskQueue

public DiskQueue(int maxInMemorySize)

Construct a disk-backed queue that keeps at most maxInMemorySize elements in memory.

Parameters:

maxInMemorySize - Maximum number of elements to keep in memory.

DiskQueue

public DiskQueue(int maxInMemorySize,
                 java.io.File tempDir)

Construct a disk-backed queue that keeps at most maxInMemorySize elements in memory.

Parameters:

maxInMemorySize - Maximum number of elements to keep in memory.

tempDir - Directory where queue temporary files will be written to.

Method Detail

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

iterator

public java.util.Iterator<java.lang.String> iterator()

Specified by:

iterator in interface java.lang.Iterable<java.lang.String>

Specified by:

iterator in interface java.util.Collection<java.lang.String>

Specified by:

iterator in class java.util.AbstractCollection<java.lang.String>

size

public int size()

Specified by:

size in interface java.util.Collection<java.lang.String>

Specified by:

size in class java.util.AbstractCollection<java.lang.String>

offer

public boolean offer(java.lang.String element)

Specified by:

offer in interface java.util.Queue<java.lang.String>

peek

public java.lang.String peek()

Specified by:

peek in interface java.util.Queue<java.lang.String>

remove

public java.lang.String remove()

Specified by:

remove in interface java.util.Queue<java.lang.String>

Overrides:

remove in class java.util.AbstractQueue<java.lang.String>

poll

public java.lang.String poll()

Specified by:

poll in interface java.util.Queue<java.lang.String>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<java.lang.String>

Overrides:

clear in class java.util.AbstractQueue<java.lang.String>