com.inaccel.coral.shm

Class Cube

java.lang.Object

com.inaccel.coral.shm.Cube

All Implemented Interfaces:

Serializable

public class Cube
extends Object
implements Serializable

This class defines methods for manipulating shared memory cubes. The content of a shared memory cube is backed by a shared memory file.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Cube.Slice This class defines methods for manipulating shared memory cube slices.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ID The id of a shared memory cube.

Constructor Summary

Constructors

Constructor and Description
Cube(String id, String pid, String namespace) Defines a shared memory cube.

Method Summary

Modifier and Type	Method and Description
static Cube	alloc(long size) Allocates a shared memory cube with the given size.
boolean	equals(Object obj)
static boolean	exists(Cube cube) Tests whether a cube exists.
static void	free(Cube cube) Frees the shared memory cube.
static Principal	getOwner(Cube cube) Returns the owner of a cube.
int	hashCode()
String	id() Returns the cube id.
static int	index(long offset, int unit) Returns the cube index of the specified offset.
static ByteBuffer[]	map(Cube cube) Maps the shared memory cube identified to the address space of the calling process.
static Long	size(Cube cube) Returns the size of a cube (in bytes).
String	toPath()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ID

public static final String ID

The id of a shared memory cube.

See Also:

Constant Field Values

Constructor Detail

Cube

public Cube(String id,
            String pid,
            String namespace)

Defines a shared memory cube.

Parameters:

id - The cube id.

pid - The cube owner's pid.

namespace - The cube owner's namespace.

Method Detail

toPath

public String toPath()

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

alloc

public static Cube alloc(long size)
                  throws FileNotFoundException,
                         IOException

Allocates a shared memory cube with the given size.

Parameters:

size - The desired size of the cube.

Returns:

The shared memory cube.

Throws:

FileNotFoundException

IOException

free

public static void free(Cube cube)

Frees the shared memory cube.

Parameters:

cube - The shared memory cube.

id

public String id()

Returns the cube id.

Returns:

The cube id.

map

public static ByteBuffer[] map(Cube cube)
                        throws FileNotFoundException,
                               IOException

Maps the shared memory cube identified to the address space of the calling process.

Parameters:

cube - The shared memory cube.

Returns:

The mapped byte buffer array.

Throws:

FileNotFoundException

IOException

exists

public static boolean exists(Cube cube)
                      throws IOException

Tests whether a cube exists.

Parameters:

cube - The shared memory cube.

Returns:

True if the cube exists; false if the cube does not exist or its existence cannot be determined.

Throws:

IOException

getOwner

public static Principal getOwner(Cube cube)
                          throws IOException

Returns the owner of a cube.

Parameters:

cube - The shared memory cube.

Returns:

A principal representing the owner of the cube.

Throws:

IOException

size

public static Long size(Cube cube)
                 throws IOException

Returns the size of a cube (in bytes).

Parameters:

cube - The shared memory cube.

Returns:

The cube size, in bytes.

Throws:

IOException

index

public static int index(long offset,
                        int unit)

Returns the cube index of the specified offset.

Parameters:

offset - The offset.

unit - The unit size.

Returns:

The cube index.