Node (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

Type Parameters:

E - the type of Entry used in the index

All Superinterfaces:

elki.persistent.Page

All Known Implementing Classes:

AbstractNode
```
public interface Node<E>
extends elki.persistent.Page
```
This interface defines the common requirements of nodes in an index structure. A node has to extend the page interface for persistent storage and has to provide an enumeration over its children.

Since:

0.1

Author:

Elke Achtert

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`int`	`addEntry(E entry)`	Adds a new entry to this node's children and returns the index of the entry in the children array.
`java.util.Iterator<IndexTreePath<E>>`	`children(IndexTreePath<E> parentPath)`	Returns an enumeration of the children paths of this node.
`E`	`getEntry(int index)`	Returns the entry at the specified index.
`int`	`getNumEntries()`	Returns the number of entries of this node.
`boolean`	`isLeaf()`	Returns true if this node is a leaf node, false otherwise.

Methods inherited from interface elki.persistent.Page
getPageID, isDirty, setDirty, setPageID

- Method Detail
  - children
```
java.util.Iterator<IndexTreePath<E>> children(IndexTreePath<E> parentPath)
```
    Returns an enumeration of the children paths of this node.
    
    Parameters:
    
    parentPath - the path to this node
    
    Returns:
    
    an enumeration of the children paths of this node
  - getNumEntries
```
int getNumEntries()
```
    Returns the number of entries of this node.
    
    Returns:
    
    the number of entries of this node
  - isLeaf
```
boolean isLeaf()
```
    Returns true if this node is a leaf node, false otherwise.
    
    Returns:
    
    true if this node is a leaf node, false otherwise
  - getEntry
```
E getEntry(int index)
```
    Returns the entry at the specified index.
    
    Parameters:
    
    index - the index of the entry to be returned
    
    Returns:
    
    the entry at the specified index
  - addEntry
```
int addEntry(E entry)
```
    Adds a new entry to this node's children and returns the index of the entry in the children array. An IllegalStateException will be thrown when inserting leaf entries into directory nodes or conversely.
    
    Parameters:
    
    entry - the entry to be added
    
    Returns:
    
    the index of the entry in this node's children array
    
    Throws:
    
    java.lang.IllegalStateException - when inserting leaf entries into non-leaf nodes or conversely