org.helidb.lang.serializer
Class DoubleSerializer

java.lang.Object
  org.helidb.lang.serializer.DoubleSerializer

All Implemented Interfaces:

Serializer<Double>

public class DoubleSerializer
extends Object
implements Serializer<Double>

A Serializer for Double values. Double values are serialized to eight bytes long byte arrays.

This object uses Double.doubleToRawLongBits(double) to encode double values. That method creates special codes for the special values Double.NaN, Double.POSITIVE_INFINITY and Double.NEGATIVE_INFINITY, and they are preserved by this object's serialization and interpretation.

This serializer does not handle null values.

The singleton instance INSTANCE may be used instead of creating a new object of this class.

Since:

1.0

Author:

Karl Gustafsson

See Also:

Double

In_jar:

helidb-core

Field Summary

static int	DATA_SIZE Eight bytes.
static DoubleSerializer	INSTANCE The singleton instance.

Constructor Summary

DoubleSerializer()

Method Summary

int	getSerializedSize() If the serialized data produced by this serializer always is of the same size, return that size (in number of bytes).
Double	interpret(byte[] barr) Interpret the data in the byte array to an object of the type handled by the Serializer implementation.
Double	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?
Double	read(InputStream is, int dataSize) Read a value from the InputStream.
Double	read(RandomAccess ra, int dataSize) Read a value from the RandomAccess' current position.
Double	readDouble(InputStream is) Read a Double value from the current position of the InputStream.
Double	readDouble(RandomAccess ra) Read a Double value from the current position of the RandomAccess.
byte[]	serialize(Double value) Serialize the supplied object into a new byte array.
int	serialize(Double value, byte[] barr, int offset) Serialize the supplied object into the byte array.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final DoubleSerializer INSTANCE

The singleton instance. May be used instead of instantiating this class.

DATA_SIZE

public static final int DATA_SIZE

Eight bytes.

See Also:

Constant Field Values

Constructor Detail

DoubleSerializer

public DoubleSerializer()

Method Detail

interpret

public Double 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<Double>

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 Double 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<Double>

Parameters:

barr - The byte array containing the data.

Returns:

The interpreted object.

See Also:

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

serialize

public int serialize(Double value,
                     byte[] barr,
                     int offset)

Description copied from interface: Serializer

Serialize the supplied object into the byte array.

Specified by:

serialize in interface Serializer<Double>

Parameters:

value - 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(Double value)

Description copied from interface: Serializer

Serialize the supplied object into a new byte array.

Specified by:

serialize in interface Serializer<Double>

Parameters:

value - The object to serialize.

Returns:

The object serialized into a byte array.

getSerializedSize

public int getSerializedSize()

Description copied from interface: Serializer

If the serialized data produced by this serializer always is of the same size, return that size (in number of bytes). Otherwise -1 is returned.

Specified by:

getSerializedSize in interface Serializer<Double>

Returns:

8, always.

isNullValuesPermitted

public boolean isNullValuesPermitted()

Description copied from interface: Serializer

Does this serializer permit null values?

Specified by:

isNullValuesPermitted in interface Serializer<Double>

Returns:

false, always.

readDouble

public Double readDouble(RandomAccess ra)
                  throws NotEnoughDataException,
                         WrappedIOException

Read a Double value from the current position of the RandomAccess.

Parameters:

ra - The RandomAccess to read from. The current position of this is incremented by 8 bytes.

Returns:

The Double value.

Throws:

NotEnoughDataException - If 8 bytes cannot be read.

WrappedIOException - On I/O errors.

readDouble

public Double readDouble(InputStream is)
                  throws NotEnoughDataException,
                         WrappedIOException

Read a Double value from the current position of the InputStream.

Parameters:

is - The InputStream to read from. The current position of the stream is incremented by 8 bytes.

Returns:

The Double value.

Throws:

NotEnoughDataException - If 8 bytes cannot be read.

WrappedIOException - If an IOException is encountered while reading data.

read

public Double read(RandomAccess ra,
                   int dataSize)

Description copied from interface: Serializer

Read a value from the RandomAccess' current position. The position in the RandomAccess is incremented by size bytes.

Specified by:

read in interface Serializer<Double>

Parameters:

ra - The RandomAccess to read from.

dataSize - The size of the value.

Returns:

The value.

read

public Double read(InputStream is,
                   int dataSize)

Description copied from interface: Serializer

Read a value from the InputStream.

Specified by:

read in interface Serializer<Double>

Parameters:

is - The InputStream to read from.

dataSize - The size of the value.

Returns:

The value.