org.h2.mvstore.type
Class ObjectDataType

java.lang.Object
  org.h2.mvstore.type.ObjectDataType

All Implemented Interfaces:

DataType

public class ObjectDataType
extends java.lang.Object
implements DataType

A data type implementation for the most common data types, including serializable objects.

Constructor Summary

ObjectDataType()

Method Summary

int	compare(java.lang.Object a, java.lang.Object b) Compare two keys.
static int	compareNotNull(byte[] data1, byte[] data2) Compare the contents of two byte arrays.
static java.lang.Object	deserialize(byte[] data) De-serialize the byte array to an object.
int	getMemory(java.lang.Object obj) Estimate the used memory in bytes.
java.lang.Object	read(java.nio.ByteBuffer buff) Read an object.
void	read(java.nio.ByteBuffer buff, java.lang.Object[] obj, int len, boolean key) Read a list of objects.
static byte[]	serialize(java.lang.Object obj) Serialize the object to a byte array.
void	write(WriteBuffer buff, java.lang.Object obj) Write an object.
void	write(WriteBuffer buff, java.lang.Object[] obj, int len, boolean key) Write a list of objects.

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectDataType

public ObjectDataType()

Method Detail

compare

public int compare(java.lang.Object a,
                   java.lang.Object b)

Description copied from interface: DataType

Compare two keys.

Specified by:

compare in interface DataType

Parameters:

a - the first key

b - the second key

Returns:

-1 if the first key is smaller, 1 if larger, and 0 if equal

getMemory

public int getMemory(java.lang.Object obj)

Description copied from interface: DataType

Estimate the used memory in bytes.

Specified by:

getMemory in interface DataType

Parameters:

obj - the object

Returns:

the used memory

read

public void read(java.nio.ByteBuffer buff,
                 java.lang.Object[] obj,
                 int len,
                 boolean key)

Description copied from interface: DataType

Read a list of objects.

Specified by:

read in interface DataType

Parameters:

buff - the target buffer

obj - the objects

len - the number of objects to read

key - whether the objects are keys

write

public void write(WriteBuffer buff,
                  java.lang.Object[] obj,
                  int len,
                  boolean key)

Description copied from interface: DataType

Write a list of objects.

Specified by:

write in interface DataType

Parameters:

buff - the target buffer

obj - the objects

len - the number of objects to write

key - whether the objects are keys

write

public void write(WriteBuffer buff,
                  java.lang.Object obj)

Description copied from interface: DataType

Write an object.

Specified by:

write in interface DataType

Parameters:

buff - the target buffer

obj - the value

read

public java.lang.Object read(java.nio.ByteBuffer buff)

Description copied from interface: DataType

Read an object.

Specified by:

read in interface DataType

Parameters:

buff - the source buffer

Returns:

the object

serialize

public static byte[] serialize(java.lang.Object obj)

Serialize the object to a byte array.

Parameters:

obj - the object to serialize

Returns:

the byte array

deserialize

public static java.lang.Object deserialize(byte[] data)

De-serialize the byte array to an object.

Parameters:

data - the byte array

Returns:

the object

compareNotNull

public static int compareNotNull(byte[] data1,
                                 byte[] data2)

Compare the contents of two byte arrays. If the content or length of the first array is smaller than the second array, -1 is returned. If the content or length of the second array is smaller than the first array, 1 is returned. If the contents and lengths are the same, 0 is returned.

This method interprets bytes as unsigned.

Parameters:

data1 - the first byte array (must not be null)

data2 - the second byte array (must not be null)

Returns:

the result of the comparison (-1, 1 or 0)