org.helidb.lang.serializer
Class FixedSizeBigIntegerNullSerializer

java.lang.Object
  org.helidb.lang.serializer.FixedSizeBigIntegerSerializer
      org.helidb.lang.serializer.FixedSizeBigIntegerNullSerializer

All Implemented Interfaces:

Serializer<BigInteger>

public class FixedSizeBigIntegerNullSerializer
extends FixedSizeBigIntegerSerializer

This Serializer serializes BigInteger values to a big-endian byte array of configurable size using BigInteger's constructor and toByteArray methods.

A value is serialized to a big-endian byte arrays using BigInteger 's constructor and toByteArray methods. Before the array containing the BigInteger data, the serialized value contains a size value of the BigInteger data (which may be less than the fixed size of this object). For fixed sizes of less than 256 bytes, one unsigned byte is used to represent the size. For sizes of 256 bytes or larger, a signed integer (four bytes) is used for the size.

The configured size of this object determines how big the serialized BigInteger:s can be. For an object size of of n bytes, where n is less than or equal to 256 bytes, the maximum BigInteger value is 2^((n - 1)*8 - 1) - 1 and the minimum value is -2^((n - 1)*8 - 1). For n values larger than 256, the maximum value is 2^((n - 4)*8 - 1) - 1 and the minimum value is -2^((n - 4)*8 - 1).

This serializer uses a special, configurable value to represent null BigInteger:s.

Since:

1.0

Author:

Karl Gustafsson

See Also:

FixedSizeBigIntegerSerializer, ConfigurableLengthLongNullSerializer, BigInteger

In_jar:

helidb-core

Constructor Summary

FixedSizeBigIntegerNullSerializer(int dataSize)
Create a new Serializer.

FixedSizeBigIntegerNullSerializer(int dataSize, BigInteger nullValue)
Create a new Serializer.

Method Summary

BigInteger	interpret(byte[] barr) Interpret the data in the byte array to an object of the type handled by the Serializer implementation.
BigInteger	interpret(byte[] barr, int offset, int length) Interpret the data in the byte array to an object of the type handled by the Serializer implementation.
boolean	isNullValuesPermitted() Does this serializer permit null values?
byte[]	serialize(BigInteger val) Serialize the supplied object into a new byte array.
int	serialize(BigInteger val, byte[] barr, int offset) Serialize the supplied object into the byte array.

Methods inherited from class org.helidb.lang.serializer.FixedSizeBigIntegerSerializer

getMaxBigIntSize, getSerializedSize, read, read, readBigInteger, readBigInteger

Methods inherited from class java.lang.Object

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

Constructor Detail

FixedSizeBigIntegerNullSerializer

public FixedSizeBigIntegerNullSerializer(int dataSize)
                                  throws IllegalArgumentException

Create a new Serializer. The special null value is the lowest value allowed with the given data size - -2^(dataSize*8 - 1). For instance, if the data size is two bytes, the null value will be -32768. That null value has the most significant bit of the most significant byte set, which may be important to know when working with Hasher:s.

Parameters:

dataSize - The size of serialized values in bytes. If the data size is 256 bytes or less, one unsigned byte is used to represent the size of the BigInteger byte array. If the data size is greater than 256 bytes, a total of five bytes is used to represent the size of the BigInteger byte array. The byte or bytes used for representing the data size are included in this parameter.

Throws:

IllegalArgumentException - If the data size is less than one byte.

FixedSizeBigIntegerNullSerializer

public FixedSizeBigIntegerNullSerializer(int dataSize,
                                         BigInteger nullValue)
                                  throws IllegalArgumentException

Create a new Serializer.

Parameters:

dataSize - The size of serialized values in bytes. If the data size is 256 bytes or less, one unsigned byte is used to represent the size of the BigInteger byte array. If the data size is greater than 256 bytes, a total of five bytes is used to represent the size of the BigInteger byte array. The byte or bytes used for representing the data size are included in this parameter.

nullValue - The BigInteger value used to represent null values.

Throws:

IllegalArgumentException - If the data size is less than one byte or if the null value cannot be serialized to a byte array with a permitted size.

Method Detail

isNullValuesPermitted

public boolean isNullValuesPermitted()

Description copied from interface: Serializer

Does this serializer permit null values?

Specified by:

isNullValuesPermitted in interface Serializer<BigInteger>

Overrides:

isNullValuesPermitted in class FixedSizeBigIntegerSerializer

Returns:

true, always.

interpret

public BigInteger interpret(byte[] barr,
                            int offset,
                            int length)

Description copied from interface: Serializer

Interpret the data in the byte array to an object of the type handled by the Serializer implementation.

Specified by:

interpret in interface Serializer<BigInteger>

Overrides:

interpret in class FixedSizeBigIntegerSerializer

Parameters:

barr - The byte array containing the data.

offset - The start position of the data.

length - The length of the data.

Returns:

The interpreted object.

See Also:

Serializer.interpret(byte[])

interpret

public BigInteger interpret(byte[] barr)

Description copied from interface: Serializer

Interpret the data in the byte array to an object of the type handled by the Serializer implementation.

Specified by:

interpret in interface Serializer<BigInteger>

Overrides:

interpret in class FixedSizeBigIntegerSerializer

Parameters:

barr - The byte array containing the data.

Returns:

The interpreted object.

See Also:

Serializer.interpret(byte[], int, int)

serialize

public int serialize(BigInteger val,
                     byte[] barr,
                     int offset)

Description copied from interface: Serializer

Serialize the supplied object into the byte array.

Specified by:

serialize in interface Serializer<BigInteger>

Overrides:

serialize in class FixedSizeBigIntegerSerializer

Parameters:

val - The object to serialize.

barr - The byte array to serialize it to.

offset - The start position to write data at in the byte array.

Returns:

The number of bytes written to the array.

serialize

public byte[] serialize(BigInteger val)

Description copied from interface: Serializer

Serialize the supplied object into a new byte array.

Specified by:

serialize in interface Serializer<BigInteger>

Overrides:

serialize in class FixedSizeBigIntegerSerializer

Parameters:

val - The object to serialize.

Returns:

The object serialized into a byte array.