org.h2.mvstore.type

Interface DataType

All Known Implementing Classes:

ObjectDataType, RowDataType, SpatialDataType, StringDataType, TransactionStore.ArrayType, TransactionStore.VersionedValueType, ValueDataType

public interface DataType

A data type.

Method Summary

Modifier and Type	Method and Description
int	compare(java.lang.Object a, java.lang.Object b) Compare two keys.
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.
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.

Method Detail

compare

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

Compare two keys.

Parameters:

a - the first key

b - the second key

Returns:

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

Throws:

java.lang.UnsupportedOperationException - if the type is not orderable

getMemory

int getMemory(java.lang.Object obj)

Estimate the used memory in bytes.

Parameters:

obj - the object

Returns:

the used memory

write

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

Write an object.

Parameters:

buff - the target buffer

obj - the value

write

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

Write a list of objects.

Parameters:

buff - the target buffer

obj - the objects

len - the number of objects to write

key - whether the objects are keys

read

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

Read an object.

Parameters:

buff - the source buffer

Returns:

the object

read

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

Read a list of objects.

Parameters:

buff - the target buffer

obj - the objects

len - the number of objects to read

key - whether the objects are keys