deegree 2.5 (2011/06/29 09:44 build-8-official)

org.deegree.io.rtree
Class PersistentPageFile

java.lang.Object
  extended by org.deegree.io.rtree.PageFile
      extended by org.deegree.io.rtree.PersistentPageFile
All Implemented Interfaces:
java.io.Serializable

 class PersistentPageFile
extends PageFile

A persistent implementation of a PageFile implemented based on a RandomAccesFile.

Structure of the File


-- Header --
int pageFileVersion
int dimension
int capacity = maxLoad + 1 for Overflow
int minimum


-- Body --
a sequence of page one after another with:
int typ - 1 LeafNode 2 NoneLeafNode
int place - index of entry of this node in father node
int counter - current used space in the node
int parentNode - page number of father node
int pageNumber - own page number
- for(i = 0; i < capacity; i++)
int data Entry i - page number of childnode or object ID of data entry
- always dependend on dimension = x
double pMin x.Dimension - pMin of the common HyperBoundingBox
double pMax x.Dimension - pMax of the common HyperBoundingBox
- for(i = 0; i < capacity; i++)
double pMin x.Dimension - pMin HyperBoundingBox for Entry i
double pMax x.Dimension - pMax HyperBoundingBox for Entry i


int entspr. 4 Bytes - double entspr. 8 Bytes


PageSize = (4 * (5 + capacity)) + (capacity + 1) * (dimension * 16)

Author:
Wolfgang Baer - WBaer@gmx.de

Field Summary
 
Fields inherited from class org.deegree.io.rtree.PageFile
capacity, dimension, minimum
 
Constructor Summary
protected PersistentPageFile(java.lang.String fileName)
          Constructor
 
Method Summary
protected  void close()
          Closes the pagefile.
protected  Node deleteNode(int pageNumber)
          Marks the node at given page number as deleted.
protected  void finalize()
           
protected  void initialize(int dimension, int capacity)
          Initializes the PersistentPageFile.
protected  Node readNode(int pageFileNumber)
          Reads a node from the PageFile for given index
protected  int writeNode(Node node)
          Writes a node into the PageFile Method tests if node has already a PageNumber, otherwise a new page number is assigned and returned.
 
Methods inherited from class org.deegree.io.rtree.PageFile
getCapacity, getDimension, getMinimum
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PersistentPageFile

protected PersistentPageFile(java.lang.String fileName)
Constructor

Parameters:
fileName -
Method Detail

initialize

protected void initialize(int dimension,
                          int capacity)
                   throws PageFileException
Initializes the PersistentPageFile. Overrides initialize in PageFile.

Overrides:
initialize in class PageFile
Parameters:
dimension - - dimension of the data
capacity - - capacity of a node
Throws:
PageFileException

readNode

protected Node readNode(int pageFileNumber)
                 throws PageFileException
Description copied from class: PageFile
Reads a node from the PageFile for given index

Specified by:
readNode in class PageFile
Parameters:
pageFileNumber - - index of page file number where node is saved
Returns:
Node
Throws:
PageFileException
See Also:
PageFile.readNode(int)

writeNode

protected int writeNode(Node node)
                 throws PageFileException
Description copied from class: PageFile
Writes a node into the PageFile Method tests if node has already a PageNumber, otherwise a new page number is assigned and returned.

Specified by:
writeNode in class PageFile
Parameters:
node - - Node to write
Returns:
int - page number
Throws:
PageFileException
See Also:
PageFile.writeNode(Node)

deleteNode

protected Node deleteNode(int pageNumber)
                   throws PageFileException
Description copied from class: PageFile
Marks the node at given page number as deleted.

Specified by:
deleteNode in class PageFile
Parameters:
pageNumber - - page number
Returns:
Node - deleted node
Throws:
PageFileException
See Also:
PageFile.deleteNode(int)

close

protected void close()
              throws PageFileException
Description copied from class: PageFile
Closes the pagefile.

Specified by:
close in class PageFile
Throws:
PageFileException
See Also:
PageFile.close()

finalize

protected void finalize()
                 throws java.lang.Throwable
Overrides:
finalize in class java.lang.Object
Throws:
java.lang.Throwable

deegree 2.5 (2011/06/29 09:44 build-8-official)

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