org.cloudgraph.store.mapping.codec

Class HashKeyFieldCodec

java.lang.Object

org.cloudgraph.store.mapping.codec.DefaultKeyFieldCodec

org.cloudgraph.store.mapping.codec.HashKeyFieldCodec

All Implemented Interfaces:

KeyFieldCodec

public class HashKeyFieldCodec
extends DefaultKeyFieldCodec
implements KeyFieldCodec

A non-lexicographic KeyFieldCodec which emits hash value bytes for the DataType specific byte representation for the given value.

This codec saves on space by terminating with the minimum added bytes possible for the hashed bytes for the native DataType.

Since:

1.1.0

Author:

Scott Cinnamond

See Also:

Type, DataFlavor, HashAlgorithmName

Field Summary

Fields

Modifier and Type	Field and Description
protected HashAlgorithmName	hashName

Fields inherited from class org.cloudgraph.store.mapping.codec.DefaultKeyFieldCodec

keyField

Constructor Summary

Constructors

Constructor and Description
HashKeyFieldCodec(KeyFieldMapping keyField, HashAlgorithmName hash)

Method Summary

Modifier and Type	Method and Description
boolean	checkEncodeOverflow(byte[] keyValue) Returns true if the given encoded value will overflow the underlying key field.
Object	decode(byte[] value) Returns the object representation for the given encoded bytes value.
byte[]	encode(Object value) Returns the encoded bytes representation for the given object or literal value.
byte[]	encodeNext(Object value) Returns the encoded "next" bytes representation for the given object or literal value, where the next value depends on the coded implementation and may typically be the lexicographic next value.
boolean	isLexicographic() Return true if the encoded values support lexicographic ordering.
boolean	isTransforming() Return true if the encoded values are fundamentally transformed father than formatted or padded in some way.

Methods inherited from class java.lang.Object

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

Field Detail

hashName

protected HashAlgorithmName hashName

Constructor Detail

HashKeyFieldCodec

public HashKeyFieldCodec(KeyFieldMapping keyField,
                         HashAlgorithmName hash)

Method Detail

isLexicographic

public boolean isLexicographic()

Description copied from interface: KeyFieldCodec

Return true if the encoded values support lexicographic ordering. For example integer values are not encoded natively but as the integer string representation.

Specified by:

isLexicographic in interface KeyFieldCodec

Returns:

true if the encoded values support lexicographic ordering

isTransforming

public boolean isTransforming()

Description copied from interface: KeyFieldCodec

Return true if the encoded values are fundamentally transformed father than formatted or padded in some way.

Specified by:

isTransforming in interface KeyFieldCodec

Returns:

true if the encoded values are fundamentally transformed father than formatted or padded in some way.

encode

public byte[] encode(Object value)

Description copied from interface: KeyFieldCodec

Returns the encoded bytes representation for the given object or literal value.

Specified by:

encode in interface KeyFieldCodec

Parameters:

value - the object or literal value

Returns:

the encoded bytes representation

checkEncodeOverflow

public boolean checkEncodeOverflow(byte[] keyValue)

Description copied from interface: KeyFieldCodec

Returns true if the given encoded value will overflow the underlying key field.

Specified by:

checkEncodeOverflow in interface KeyFieldCodec

Returns:

true if the given encoded value will overflow the underlying key field.

decode

public Object decode(byte[] value)

Description copied from interface: KeyFieldCodec

Returns the object representation for the given encoded bytes value.

Specified by:

decode in interface KeyFieldCodec

Parameters:

value - encoded bytes value

Returns:

the object representation for the given encoded bytes value

encodeNext

public byte[] encodeNext(Object value)

Description copied from interface: KeyFieldCodec

Returns the encoded "next" bytes representation for the given object or literal value, where the next value depends on the coded implementation and may typically be the lexicographic next value.

Specified by:

encodeNext in interface KeyFieldCodec

Parameters:

value - the object or literal value

Returns:

the encoded bytes representation