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

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.
java.nio.ByteBuffer	write(java.nio.ByteBuffer buff, java.lang.Object obj) Write the object.

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

java.nio.ByteBuffer write(java.nio.ByteBuffer buff,
                          java.lang.Object obj)

Write the object.

Parameters:

buff - the target buffer

obj - the value

Returns:

the byte buffer

read

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

Read an object.

Parameters:

buff - the source buffer

Returns:

the object