org.das2.qstream

Class TransferType

java.lang.Object

org.das2.qstream.TransferType

Direct Known Subclasses:

AsciiTransferType, DoubleTransferType, FloatTransferType, IntegerTransferType, LongTransferType, ShortTransferType

public abstract class TransferType
extends java.lang.Object

A transfer type is an encoding of a double on to the stream. It must have a fixed length in bytes. Some are pure ASCII, and isAscii can be used to check this.

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.util.logging.Logger	logger

Constructor Summary

Constructors

Constructor and Description
TransferType()

Method Summary

Modifier and Type	Method and Description
static java.nio.ByteBuffer	allocate(int recordLengthBytes, java.nio.ByteOrder byteOrder) convenient method which gently reminds that the ByteOrder needs to be specified with ByteBuffers.
static TransferType	getForName(java.lang.String ttype, java.util.Map<java.lang.String,java.lang.Object> properties) returns a TranferType for the given name, or null if none is found.
abstract boolean	isAscii() return true if the transfer type uses ASCII-encodings to represent data.
abstract java.lang.String	name() return a string identifying the TransferType.
abstract double	read(java.nio.ByteBuffer buffer) read the data from the buffer.
abstract int	sizeBytes() return the number of bytes used by the transfer type.
java.lang.String	toString()
abstract void	write(double d, java.nio.ByteBuffer buffer) write the data to the buffer.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected static final java.util.logging.Logger logger

Constructor Detail

TransferType

public TransferType()

Method Detail

getForName

public static TransferType getForName(java.lang.String ttype,
                                      java.util.Map<java.lang.String,java.lang.Object> properties)

returns a TranferType for the given name, or null if none is found.

Parameters:

ttype -

properties - map of dataset properties. Introduced to pass in time Unit to AsciiTimeTransferType without unduly coupling codes.

Returns:

returns a TranferType for the given name, or null if none is found.

write

public abstract void write(double d,
                           java.nio.ByteBuffer buffer)

write the data to the buffer. The buffer's position should be incremented by sizeBytes.

Parameters:

d - the value to write.

buffer - the byte buffer positioned to receive sizeByte bytes.

read

public abstract double read(java.nio.ByteBuffer buffer)

read the data from the buffer. The implementations will increment the buffer's position by sizeBytes.

Parameters:

buffer - the container for the transfer type.

Returns:

the value read

sizeBytes

public abstract int sizeBytes()

return the number of bytes used by the transfer type.

Returns:

the size of the type in bytes.

isAscii

public abstract boolean isAscii()

return true if the transfer type uses ASCII-encodings to represent data. It's assumed in this case that trailing whitespace can be modified for readability.

Returns:

true if the type is ASCII-based.

name

public abstract java.lang.String name()

return a string identifying the TransferType.

Returns:

the name

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

allocate

public static java.nio.ByteBuffer allocate(int recordLengthBytes,
                                           java.nio.ByteOrder byteOrder)

convenient method which gently reminds that the ByteOrder needs to be specified with ByteBuffers. ByteBuffers are created with big endian turned on, but more often little endian is used.

Parameters:

recordLengthBytes -

byteOrder -

Returns:

the byte buffer with the order set.