fiftyone.mobile.detection.entities.stream
Class BaseList<T extends BaseEntity>

java.lang.Object
  fiftyone.mobile.detection.entities.stream.BaseList<T>

All Implemented Interfaces:

Disposable, ICacheList, ReadonlyList<T>, Iterable<T>

Direct Known Subclasses:

StreamFixedList, StreamVariableList

public abstract class BaseList<T extends BaseEntity>
extends Object
implements ReadonlyList<T>, ICacheList, Disposable

Lists can be stored as a set of related objects entirely within memory, or the relevant objects loaded as required from a file or other permanent store as required.

This class provides core functions needed for lists which load objects as required. It implements the Cache to store frequently requested objects and improve memory usage and performance.

Interface implementations are used to create new instances of items to add to the list in order to avoid creating many inherited list classes for each BaseEntity type.

Should not be referenced directly.

Field Summary

Cache<T>	cache Used to store previously accessed items to improve performance and reduce memory consumption associated with creating new instances of entities already in use.
protected Dataset	dataSet The dataset which contains the list.
(package private) BaseEntityFactory<T>	entityFactory
(package private) Header	header Information about the data structure the list is associated with.
(package private) Pool	pool Pools of binary readers connected to the data source.

Constructor Summary

BaseList(Dataset dataSet, BinaryReader reader, Source source, BaseEntityFactory<T> entityFactory)
Constructs a new instance of BaseList ready to read entities from the source.

Method Summary

protected abstract T	createEntity(int offset, BinaryReader reader)
void	dispose() Disposes of the pool of readers.
T	get(int offsetOrIndex) Retrieves the record at the offset or index requested
int	getCount()
double	getPercentageMisses()
int	size()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

iterator

Field Detail

cache

public final Cache<T extends BaseEntity> cache

Used to store previously accessed items to improve performance and reduce memory consumption associated with creating new instances of entities already in use.

pool

final Pool pool

Pools of binary readers connected to the data source.

dataSet

protected final Dataset dataSet

The dataset which contains the list.

header

final Header header

Information about the data structure the list is associated with.

entityFactory

final BaseEntityFactory<T extends BaseEntity> entityFactory

Constructor Detail

BaseList

public BaseList(Dataset dataSet,
                BinaryReader reader,
                Source source,
                BaseEntityFactory<T> entityFactory)

Constructs a new instance of BaseList ready to read entities from the source.

Parameters:

dataSet - Dataset being created

reader - Reader used to initialise the header only

source - Source data file containing the entire data structure

Method Detail

createEntity

protected abstract T createEntity(int offset,
                                  BinaryReader reader)
                                              throws IOException

Throws:

IOException

getPercentageMisses

public double getPercentageMisses()

Specified by:

getPercentageMisses in interface ICacheList

getCount

public int getCount()

get

public T get(int offsetOrIndex)
                         throws IOException

Retrieves the record at the offset or index requested

Specified by:

get in interface ReadonlyList<T extends BaseEntity>

Parameters:

offsetOrIndex - Index or offset of the record required

Returns:

A new instance of the item at the offset or index

Throws:

IOException

dispose

public void dispose()

Disposes of the pool of readers.

Specified by:

dispose in interface Disposable

size

public int size()

Specified by:

size in interface ReadonlyList<T extends BaseEntity>