Package elki.persistent

Interface PageHeader

All Known Implementing Classes:

DefaultPageHeader, MkTreeHeader, RdKNNTreeHeader, TreeIndexHeader

public interface PageHeader

Defines the requirements for a header of a persistent page file. A header must at least store the size of a page in Bytes.

Since:

0.1

Author:

Elke Achtert

Method Summary

Modifier and Type	Method	Description
int	getPageSize()	Returns the size of a page in Bytes.
int	getReservedPages()	Returns the number of pages necessary for the header
void	readHeader(java.nio.ByteBuffer data)	Initializes this header from the specified file.
default void	readHeader(java.nio.channels.FileChannel file)	Read the header from an input file.
int	size()	Returns the size of this header in Bytes.
void	writeHeader(java.nio.ByteBuffer buffer)	Writes this header to the specified file.
default void	writeHeader(java.nio.channels.FileChannel file)	Read the header from an input file.

Method Detail

size

int size()

Returns the size of this header in Bytes.

Returns:

the size of this header in Bytes

readHeader

default void readHeader(java.nio.channels.FileChannel file)
                 throws java.io.IOException

Read the header from an input file.

Parameters:

file - File to read from

Throws:

java.io.IOException

readHeader

void readHeader(java.nio.ByteBuffer data)

Initializes this header from the specified file.

Parameters:

data - byte array with the page data.

writeHeader

default void writeHeader(java.nio.channels.FileChannel file)
                  throws java.io.IOException

Read the header from an input file.

Parameters:

file - File to read from

Throws:

java.io.IOException

writeHeader

void writeHeader(java.nio.ByteBuffer buffer)
          throws java.io.IOException

Writes this header to the specified file.

Parameters:

buffer - Buffer to write to

Throws:

java.io.IOException - IOException if an I/O-error occurs during writing

getPageSize

int getPageSize()

Returns the size of a page in Bytes.

Returns:

the size of a page in Bytes

getReservedPages

int getReservedPages()

Returns the number of pages necessary for the header

Returns:

the number of pages