fiftyone.mobile.detection.entities.stream

Class StreamBaseList<T extends BaseEntity>

java.lang.Object

fiftyone.mobile.detection.entities.stream.StreamBaseList<T>

Type Parameters:

T - The type of BaseEntity the list will contain.

Direct Known Subclasses:

StreamCacheList, StreamFixedList

public abstract class StreamBaseList<T extends BaseEntity>
extends Object

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.

Delegate methods 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.

Objects of this class should not be created directly as they are part of the internal logic.

Field Summary

Fields

Modifier and Type	Field and Description
protected Dataset	dataSet The dataset which contains the list.
protected Header	header Information about the data structure the list is associated with.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
protected abstract T	createEntity(int key, BinaryReader reader) Used to create a new entity of type T when an item is required from the list.
T	get(int key) Retrieves the record at the offset or index requested.
int	size() Returns The number of items in the list.

Methods inherited from class java.lang.Object

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

Field Detail

dataSet

protected final Dataset dataSet

The dataset which contains the list.

header

protected final Header header

Information about the data structure the list is associated with.

Constructor Detail

StreamBaseList

public StreamBaseList(Dataset dataSet,
                      BinaryReader reader,
                      BaseEntityFactory<T> entityFactory)

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

Parameters:

dataSet - Dataset being created.

reader - Reader used to initialise the header only.

entityFactory - a base entity factory to be used.

Method Detail

createEntity

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

Used to create a new entity of type T when an item is required from the list.

Parameters:

key - The offset position in the data structure to the entity to be returned from the list, or the index of the entity to be returned from the list.

reader - Reader connected to the source data structure and positioned to start reading.

Returns:

A new instance of type T.

Throws:

IOException - if there was a problem accessing data file.

get

public T get(int key)
      throws IOException

Retrieves the record at the offset or index requested.

Parameters:

key - Index or offset of the record required.

Returns:

A new instance of the item at the offset or index.

Throws:

IOException - if there was a problem accessing data file.

size

public int size()

Returns The number of items in the list.

Returns:

The number of items in the list.