Package org.palladiosimulator.edp2.repository.local.dao.internal.backgroundlist

Class BackgroundMemoryListImpl<V,Q extends javax.measure.quantity.Quantity>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<javax.measure.Measure<V,Q>>

org.palladiosimulator.edp2.repository.local.dao.internal.backgroundlist.BackgroundMemoryListImpl<V,Q>

Type Parameters:

V - Value type of the measurements to be stored. Most often used values are Double or Long

Q - Quantity to be stored, see Quantity

All Implemented Interfaces:

Iterable<javax.measure.Measure<V,Q>>, Collection<javax.measure.Measure<V,Q>>, List<javax.measure.Measure<V,Q>>, BackgroundMemoryList<V,Q>, BinaryMeasurementsList<V,Q>

public class BackgroundMemoryListImpl<V,Q extends javax.measure.quantity.Quantity>
extends AbstractList<javax.measure.Measure<V,Q>>
implements BackgroundMemoryList<V,Q>

A generic list implementation that consumes a constant amount of main memory regardless of the number of elements in the list. It relies on HDD memory as background storage. It uses views on the data stored in form of chunks. A chunk contains a limited number of data elements. Chunks are (de-)serialized to disk depending on the requested data elements. The list has some restrictions: First, all elements have to be serializable with constant memory footprint. Second, deletion of elements in the list is not implemented. Third, insertion is only possible at the end of the list. Fourth, all list elements are persisted with the same unit, so unit conversion and conversion losses may apply.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BackgroundMemoryListImpl.BinaryRepresentation	Describes the representation and storage of the values in binary format.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_CHUNK_SIZE	Default Number of data elements per chunk.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
BackgroundMemoryListImpl(String absoluteFilename, Serializer<V> serialiser, int chunkSize, BackgroundMemoryListImpl.BinaryRepresentation binaryRepresentation, javax.measure.unit.Unit<Q> unit)	Constructor for background memory lists.
BackgroundMemoryListImpl(String absoluteFilename, Serializer<V> serialiser, BackgroundMemoryListImpl.BinaryRepresentation binaryRepresentation, javax.measure.unit.Unit<Q> unit)	Constructor for background memory lists.

Method Summary

Modifier and Type	Method	Description
void	add(int index, javax.measure.Measure<V,Q> element)
void	close()	Closes the link to the file on background storage.
void	flush()
javax.measure.Measure<V,Q>	get(int index)
boolean	isClosed()	Get the status of the link to the attached file.
void	open()	Opens the link to the file on background storage.
javax.measure.Measure<V,Q>	remove(int index)
javax.measure.Measure<V,Q>	set(int index, javax.measure.Measure<V,Q> element)
int	size()

Methods inherited from class java.util.AbstractList

add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

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

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

add, addAll, addAll, clear, contains, containsAll, equals, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, removeAll, replaceAll, retainAll, sort, spliterator, subList, toArray, toArray

Field Detail

DEFAULT_CHUNK_SIZE

public static final int DEFAULT_CHUNK_SIZE

Default Number of data elements per chunk.

See Also:

Constant Field Values

Constructor Detail

BackgroundMemoryListImpl

public BackgroundMemoryListImpl(String absoluteFilename,
                                Serializer<V> serialiser,
                                BackgroundMemoryListImpl.BinaryRepresentation binaryRepresentation,
                                javax.measure.unit.Unit<Q> unit)
                         throws IOException

Constructor for background memory lists.

Parameters:

absoluteFilename - Path to the file used as background storage.

serialiser - The (de-)serializer to use upon serialization of data to the background storage.

Throws:

IOException - Thrown if file IO fails.

BackgroundMemoryListImpl

public BackgroundMemoryListImpl(String absoluteFilename,
                                Serializer<V> serialiser,
                                int chunkSize,
                                BackgroundMemoryListImpl.BinaryRepresentation binaryRepresentation,
                                javax.measure.unit.Unit<Q> unit)
                         throws IOException

Constructor for background memory lists.

Parameters:

absoluteFilename - Path to the file used as background storage.

serialiser - The (de-)serializer to use upon serialization of data to the background storage.

chunkSize - The size of the chunk in elements which should be used.

Throws:

IOException - Thrown if file IO fails.

Method Detail

open

public void open()
          throws IOException

Description copied from interface: BackgroundMemoryList

Opens the link to the file on background storage. Only allowed if there is no open link.

Specified by:

open in interface BackgroundMemoryList<V,Q extends javax.measure.quantity.Quantity>

Throws:

IOException - Thrown if file IO fails.

isClosed

public boolean isClosed()

Description copied from interface: BackgroundMemoryList

Get the status of the link to the attached file. Any read or write operation is only allowed in open state.

Specified by:

isClosed in interface BackgroundMemoryList<V,Q extends javax.measure.quantity.Quantity>

Returns:

true if the link to the attached file is closed.

add

public void add(int index,
                javax.measure.Measure<V,Q> element)

Specified by:

add in interface List<V>

Overrides:

add in class AbstractList<javax.measure.Measure<V,Q extends javax.measure.quantity.Quantity>>

get

public javax.measure.Measure<V,Q> get(int index)

Specified by:

get in interface List<V>

Specified by:

get in class AbstractList<javax.measure.Measure<V,Q extends javax.measure.quantity.Quantity>>

set

public javax.measure.Measure<V,Q> set(int index,
                                            javax.measure.Measure<V,Q> element)

Specified by:

set in interface List<V>

Overrides:

set in class AbstractList<javax.measure.Measure<V,Q extends javax.measure.quantity.Quantity>>

remove

public javax.measure.Measure<V,Q> remove(int index)

Specified by:

remove in interface List<V>

Overrides:

remove in class AbstractList<javax.measure.Measure<V,Q extends javax.measure.quantity.Quantity>>

size

public int size()

Specified by:

size in interface Collection<V>

Specified by:

size in interface List<V>

Specified by:

size in class AbstractCollection<javax.measure.Measure<V,Q extends javax.measure.quantity.Quantity>>

close

public void close()
           throws IOException

Description copied from interface: BackgroundMemoryList

Closes the link to the file on background storage. There are no further add or get operations allowed after closing.

Specified by:

close in interface BackgroundMemoryList<V,Q extends javax.measure.quantity.Quantity>

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface BackgroundMemoryList<V,Q extends javax.measure.quantity.Quantity>

Throws:

IOException