Environment for
DeveLoping
KDD-Applications
Supported by Index-Structures

de.lmu.ifi.dbs.elki.index.tree
Class TreeIndexHeader

java.lang.Object
  extended by de.lmu.ifi.dbs.elki.persistent.DefaultPageHeader
      extended by de.lmu.ifi.dbs.elki.index.tree.TreeIndexHeader
All Implemented Interfaces:
PageHeader
Direct Known Subclasses:
MkMaxTreeHeader, RdKNNTreeHeader

public class TreeIndexHeader
extends DefaultPageHeader

Encapsulates the header information of a tree like index structure. This information is needed for persistent storage.

Author:
Elke Achtert

Field Summary
(package private)  int dirCapacity
          The capacity of a directory node (= 1 + maximum number of entries in a directory node).
(package private)  int dirMinimum
          The minimum number of entries in a directory node.
(package private)  int leafCapacity
          The capacity of a leaf node (= 1 + maximum number of entries in a leaf node).
(package private)  int leafMinimum
          The minimum number of entries in a leaf node.
private static int SIZE
          The size of this header.
 
Constructor Summary
TreeIndexHeader()
          Empty constructor for serialization.
TreeIndexHeader(int pageSize, int dirCapacity, int leafCapacity, int dirMinimum, int leafMinimum)
          Creates a nerw header with the specified parameters.
 
Method Summary
 int getDirCapacity()
          Returns the capacity of a directory node (= 1 + maximum number of entries in a directory node).
 int getDirMinimum()
          Returns the minmum number of entries in a directory node.
 int getLeafCapacity()
          Returns the capacity of a leaf node (= 1 + maximum number of entries in a leaf node).
 int getLeafMinimum()
          Returns the minmum number of entries in a leaf node.
 void readHeader(RandomAccessFile file)
          Initializes this header from the specified file,
 int size()
          Returns the size of this header in Bytes.
 void writeHeader(RandomAccessFile file)
          Writes this header to the specified file,
 
Methods inherited from class de.lmu.ifi.dbs.elki.persistent.DefaultPageHeader
getPageSize
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

SIZE

private static int SIZE
The size of this header.


dirCapacity

int dirCapacity
The capacity of a directory node (= 1 + maximum number of entries in a directory node).


leafCapacity

int leafCapacity
The capacity of a leaf node (= 1 + maximum number of entries in a leaf node).


dirMinimum

int dirMinimum
The minimum number of entries in a directory node.


leafMinimum

int leafMinimum
The minimum number of entries in a leaf node.

Constructor Detail

TreeIndexHeader

public TreeIndexHeader()
Empty constructor for serialization.


TreeIndexHeader

public TreeIndexHeader(int pageSize,
                       int dirCapacity,
                       int leafCapacity,
                       int dirMinimum,
                       int leafMinimum)
Creates a nerw header with the specified parameters.

Parameters:
pageSize - the size of a page in bytes
dirCapacity - the maximum number of entries in a directory node
leafCapacity - the maximum number of entries in a leaf node
dirMinimum - the minmum number of entries in a directory node
leafMinimum - the minmum number of entries in a leaf node
Method Detail

readHeader

public void readHeader(RandomAccessFile file)
                throws IOException
Initializes this header from the specified file,

Specified by:
readHeader in interface PageHeader
Overrides:
readHeader in class DefaultPageHeader
Parameters:
file - the file to which this header belongs
Throws:
IOException

writeHeader

public void writeHeader(RandomAccessFile file)
                 throws IOException
Writes this header to the specified file,

Specified by:
writeHeader in interface PageHeader
Overrides:
writeHeader in class DefaultPageHeader
Parameters:
file - the file to which this header belongs
Throws:
IOException

getDirCapacity

public int getDirCapacity()
Returns the capacity of a directory node (= 1 + maximum number of entries in a directory node).

Returns:
the capacity of a directory node (= 1 + maximum number of entries in a directory node)

getLeafCapacity

public int getLeafCapacity()
Returns the capacity of a leaf node (= 1 + maximum number of entries in a leaf node).

Returns:
the capacity of a leaf node (= 1 + maximum number of entries in a leaf node)

getDirMinimum

public int getDirMinimum()
Returns the minmum number of entries in a directory node.

Returns:
the minmum number of entries in a directory node

getLeafMinimum

public int getLeafMinimum()
Returns the minmum number of entries in a leaf node.

Returns:
the minmum number of entries in a leaf node

size

public int size()
Returns the size of this header in Bytes.

Specified by:
size in interface PageHeader
Overrides:
size in class DefaultPageHeader
Returns:
the size of this header in Bytes

Release 0.1 (2008-07-10_1838)