org.exist.storage
Class StorageAddress

java.lang.Object
  org.exist.storage.StorageAddress

public class StorageAddress
extends Object

Represents a (virtual) storage address in the paged file, consisting of page number, tuple id and type indicator. The format of a storage address is as follows:

 | page    | type | tid |
 | 1 2 3 4 | 5 6   | 7 8 |
 

Constructor Summary

StorageAddress()

Method Summary

static long	createPointer(int page, short tid) Create virtual address from page number and offset (tid)
static long	createPointer(int page, short tid, short flags)
static boolean	equals(long p0, long p1) Returns true if the page number and tid of the two storage addresses is equal.
static short	indexTypeFromPointer(long pointer) Get the type indicator from a virtual address.
static int	pageFromPointer(long pointer) Get the page from a virtual address.
static long	read(VariableByteInput is)
static long	setIndexType(long pointer, short type)
static short	tidFromPointer(long pointer) Get the tid (tuple id) from a virtual address.
static String	toString(long pointer)
static void	write(long pointer, VariableByteOutputStream os)

Methods inherited from class java.lang.Object

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

Constructor Detail

StorageAddress

public StorageAddress()

Method Detail

createPointer

public static final long createPointer(int page,
                                       short tid)

Create virtual address from page number and offset (tid)

Parameters:

page - page number

tid - offset

Returns:

new virtual address in a long

createPointer

public static final long createPointer(int page,
                                       short tid,
                                       short flags)

tidFromPointer

public static final short tidFromPointer(long pointer)

Get the tid (tuple id) from a virtual address.

Parameters:

pointer -

Returns:

the tid encoded in this address

pageFromPointer

public static final int pageFromPointer(long pointer)

Get the page from a virtual address.

Parameters:

pointer -

Returns:

the page encoded in this address

indexTypeFromPointer

public static final short indexTypeFromPointer(long pointer)

Get the type indicator from a virtual address. Returns a short corresponding to the type constants defined in Type.

Parameters:

pointer -

Returns:

type indicator from a virtual address

setIndexType

public static final long setIndexType(long pointer,
                                      short type)

equals

public static final boolean equals(long p0,
                                   long p1)

Returns true if the page number and tid of the two storage addresses is equal. The type indicator is ignored.

Parameters:

p0 -

p1 -

Returns:

true if the page number and tid of the two storage addresses is equal

write

public static final void write(long pointer,
                               VariableByteOutputStream os)

read

public static final long read(VariableByteInput is)
                       throws IOException,
                              EOFException

Throws:

IOException

EOFException

toString

public static final String toString(long pointer)