net.sf.farrago.runtime
Class FennelTupleWriter

java.lang.Object
  net.sf.farrago.runtime.FennelTupleWriter

public abstract class FennelTupleWriter
extends Object

FennelTupleWriter defines an interface for marshalling tuples to be sent to Fennel. Implementations are responsible for marshalling specific tuple formats.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/runtime/FennelTupleWriter.java#19 $

Author:

John V. Sichi

Field Summary

private static long	MAGIC_NUMBER Matches fennel/tuple/TupleAccessor.cpp.
private static FennelTupleAccessor	tupleAligner Singleton helper for aligning tuple buffers correctly.

Constructor Summary

FennelTupleWriter()

Method Summary

boolean	marshalTuple(ByteBuffer byteBuffer, Object object) Marshals one tuple if it can fit.
protected abstract void	marshalTupleOrThrow(ByteBuffer sliceBuffer, Object object) Marshals one tuple if it can fit; otherwise, throws either BufferOverflowException or IndexOutOfBoundsException (depending on whether absolute or relative puts are used).

Methods inherited from class java.lang.Object

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

Field Detail

MAGIC_NUMBER

private static long MAGIC_NUMBER

Matches fennel/tuple/TupleAccessor.cpp.

tupleAligner

private static FennelTupleAccessor tupleAligner

Singleton helper for aligning tuple buffers correctly.

Constructor Detail

FennelTupleWriter

public FennelTupleWriter()

Method Detail

marshalTupleOrThrow

protected abstract void marshalTupleOrThrow(ByteBuffer sliceBuffer,
                                            Object object)

Marshals one tuple if it can fit; otherwise, throws either BufferOverflowException or IndexOutOfBoundsException (depending on whether absolute or relative puts are used).

Parameters:

sliceBuffer - buffer to be filled with marshalled tuple data; on entry, the buffer position is 0; on return, the buffer position should be the unaligned end of the tuple

object - subclass-specific object to be marshalled

Throws:

BufferOverflowException - see above

IndexOutOfBoundsException - see above

marshalTuple

public boolean marshalTuple(ByteBuffer byteBuffer,
                            Object object)

Marshals one tuple if it can fit.

Parameters:

byteBuffer - buffer to be filled with marshalled tuple data, starting at current buffer position; on return, the buffer position should be the unaligned end of the tuple

object - subclass-specific object to be marshalled

Returns:

whether the marshalled tuple fit in the available buffer space