org.refcodes.serial.AbstractReferenceeLengthSegment Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of refcodes-serial Show documentation
Artifact providing generic (byte) serialization functionality including a TTY-/COM-Port implementation of the serial framework as well as a (local) loopback port.
The newest version!
// /////////////////////////////////////////////////////////////////////////////
// REFCODES.ORG
// /////////////////////////////////////////////////////////////////////////////
// This code is copyright (c) by Siegfried Steiner, Munich, Germany, distributed
// on an "AS IS" BASIS WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, and licen-
// sed under the following (see "http://en.wikipedia.org/wiki/Multi-licensing")
// licenses:
// -----------------------------------------------------------------------------
// GNU General Public License, v3.0 ("http://www.gnu.org/licenses/gpl-3.0.html")
// -----------------------------------------------------------------------------
// Apache License, v2.0 ("http://www.apache.org/licenses/TEXT-2.0")
// -----------------------------------------------------------------------------
// Please contact the copyright holding author(s) of the software artifacts in
// question for licensing issues not being covered by the above listed licenses,
// also regarding commercial licensing models or regarding the compatibility
// with other open source licenses.
// /////////////////////////////////////////////////////////////////////////////

package org.refcodes.serial;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Objects;

import org.refcodes.numerical.Endianess;
import org.refcodes.numerical.EndianessAccessor;
import org.refcodes.serial.Transmission.TransmissionMixin;
import org.refcodes.struct.SimpleTypeMap;
import org.refcodes.struct.SimpleTypeMapImpl;

/**
 * The {@link AbstractReferenceeLengthSegment} represents a allocated length
 * value as of the referenced {@link Transmission} element's length.
 *
 * @param  the generic type
 */
public abstract class AbstractReferenceeLengthSegment implements Segment, TransmissionMixin, LengthWidthAccessor, EndianessAccessor, AllocLengthAccessor {

	// /////////////////////////////////////////////////////////////////////////
	// STATICS:
	// /////////////////////////////////////////////////////////////////////////

	private static final long serialVersionUID = 1L;

	// /////////////////////////////////////////////////////////////////////////
	// CONSTANTS:
	// /////////////////////////////////////////////////////////////////////////

	public static final String ALLOC_LENGTH = "ALLOC_LENGTH";
	public static final String ALLOC_LENGTH_WIDTH = "ALLOC_LENGTH_WIDTH";
	public static final String ENDIANESS = "ENDIANESS";

	// /////////////////////////////////////////////////////////////////////////
	// VARIABLES:
	// /////////////////////////////////////////////////////////////////////////

	protected Endianess _endianess;
	protected int _lengthWidth;
	protected int _allocLength = -1;
	protected REFERENCEE _referencee = null; // Either referencee or decoratee!

	// /////////////////////////////////////////////////////////////////////////
	// CONSTRUCTORS:
	// /////////////////////////////////////////////////////////////////////////

	/**
	 * Constructs an according instance. The configuration attributes are taken
	 * from the {@link TransmissionMetrics} configuration object, though only
	 * those attributes are supported which are also supported by the other
	 * constructors!
	 * 
	 * @param aTransmissionMetrics The {@link TransmissionMetrics} to be used
	 *        for configuring this instance.
	 */
	public AbstractReferenceeLengthSegment( TransmissionMetrics aTransmissionMetrics ) {
		this( aTransmissionMetrics.getLengthWidth(), aTransmissionMetrics.getEndianess() );
	}

	/**
	 * Constructs an according instance. The configuration attributes are taken
	 * from the {@link TransmissionMetrics} configuration object, though only
	 * those attributes are supported which are also supported by the other
	 * constructors!
	 * 
	 * @param aReferencee The referenced {@link Transmission} which's length is
	 *        to be used.
	 * @param aTransmissionMetrics The {@link TransmissionMetrics} to be used
	 *        for configuring this instance.
	 */
	public AbstractReferenceeLengthSegment( REFERENCEE aReferencee, TransmissionMetrics aTransmissionMetrics ) {
		this( aReferencee, aTransmissionMetrics.getLengthWidth(), aTransmissionMetrics.getEndianess() );
	}

	// -------------------------------------------------------------------------

	/**
	 * Constructs an empty allocation value with a width of
	 * {@link TransmissionMetrics#DEFAULT_LENGTH_WIDTH} bytes used to specify
	 * the decoratee's length and a
	 * {@link TransmissionMetrics#DEFAULT_ENDIANESS} endian representation of
	 * the decoratee's length.
	 */
	public AbstractReferenceeLengthSegment() {
		this( TransmissionMetrics.DEFAULT_LENGTH_WIDTH, TransmissionMetrics.DEFAULT_ENDIANESS );
	}

	/**
	 * Constructs an empty allocation value with a width of
	 * {@link TransmissionMetrics#DEFAULT_LENGTH_WIDTH} bytes used to specify
	 * the decoratee's length and the provided {@link Endianess} representation
	 * of the decoratee's length.
	 * 
	 * @param aEndianess The {@link Endianess} to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( Endianess aEndianess ) {
		this( TransmissionMetrics.DEFAULT_LENGTH_WIDTH, aEndianess );
	}

	/**
	 * Constructs an empty allocation value with the given number of bytes used
	 * to specify the decoratee's length and a
	 * {@link TransmissionMetrics#DEFAULT_ENDIANESS} endian representation of
	 * the decoratee's length.
	 * 
	 * @param aLengthWidth The width (in bytes) to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( int aLengthWidth ) {
		this( aLengthWidth, TransmissionMetrics.DEFAULT_ENDIANESS );
	}

	/**
	 * Constructs an empty allocation value with the given number of bytes used
	 * to specify the decoratee's length and the provided {@link Endianess}
	 * representation of the decoratee's length.
	 * 
	 * @param aLengthWidth The width (in bytes) to be used for length values.
	 * @param aEndianess The {@link Endianess} to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( int aLengthWidth, Endianess aEndianess ) {
		this( null, aLengthWidth, aEndianess );
	}

	/**
	 * Constructs the allocation value with the given decoratee and a width of
	 * {@link TransmissionMetrics#DEFAULT_LENGTH_WIDTH} bytes used to specify
	 * the decoratee's length a {@link TransmissionMetrics#DEFAULT_ENDIANESS}
	 * endian representation of the decoratee's length.
	 * 
	 * @param aReferencee The decoratee used for this allocation value.
	 */
	public AbstractReferenceeLengthSegment( REFERENCEE aReferencee ) {
		this( aReferencee, TransmissionMetrics.DEFAULT_LENGTH_WIDTH, TransmissionMetrics.DEFAULT_ENDIANESS );
	}

	/**
	 * Constructs the allocation value with the given decoratee and a width of
	 * {@link TransmissionMetrics#DEFAULT_LENGTH_WIDTH} bytes used to specify
	 * the decoratee's length and the provided {@link Endianess} representation
	 * of the decoratee's length.
	 *
	 * @param aReferencee The decoratee used for this allocation value.
	 * @param aEndianess The {@link Endianess} to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( REFERENCEE aReferencee, Endianess aEndianess ) {
		this( aReferencee, TransmissionMetrics.DEFAULT_LENGTH_WIDTH, aEndianess );
	}

	/**
	 * Constructs the allocation value with the given decoratee and with the
	 * given number of bytes used to specify the decoratee's length and a
	 * {@link TransmissionMetrics#DEFAULT_ENDIANESS} endian representation of
	 * the decoratee's length.
	 *
	 * @param aReferencee The decoratee used for this allocation value.
	 * @param aLengthWidth The width (in bytes) to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( REFERENCEE aReferencee, int aLengthWidth ) {
		this( aReferencee, aLengthWidth, TransmissionMetrics.DEFAULT_ENDIANESS );
	}

	/**
	 * Constructs the allocation value with the given decoratee and with the
	 * given number of bytes used to specify the decoratee's length and the
	 * provided {@link Endianess} representation of the decoratee's length.
	 *
	 * @param aReferencee The decoratee used for this allocation value.
	 * @param aLengthWidth The width (in bytes) to be used for length values.
	 * @param aEndianess The {@link Endianess} to be used for length values.
	 */
	public AbstractReferenceeLengthSegment( REFERENCEE aReferencee, int aLengthWidth, Endianess aEndianess ) {
		_endianess = aEndianess;
		_lengthWidth = aLengthWidth;
		_referencee = aReferencee;
	}

	// /////////////////////////////////////////////////////////////////////////
	// METHODS:
	// /////////////////////////////////////////////////////////////////////////

	/**
	 * {@inheritDoc}
	 */
	@Override
	public int getLengthWidth() {
		return _lengthWidth;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Sequence toSequence() {
		final int theAllocLength = _allocLength != -1 ? _allocLength : _referencee != null ? _referencee.getLength() : 0;
		if ( _allocLength == -1 ) {
			_allocLength = theAllocLength;
		}
		return new ByteArraySequence( _endianess.toBytes( theAllocLength, _lengthWidth ) );
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public int fromTransmission( Sequence aSequence, int aOffset ) throws TransmissionException {
		final byte[] theBuffer = aSequence.toBytes( aOffset, _lengthWidth );
		_allocLength = _endianess.toUnsignedInteger( theBuffer );
		return aOffset + _lengthWidth;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void receiveFrom( InputStream aInputStream, OutputStream aReturnStream ) throws IOException {
		final byte[] theBuffer = new byte[_lengthWidth];
		aInputStream.read( theBuffer, 0, _lengthWidth );
		_allocLength = _endianess.toUnsignedInteger( theBuffer );
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public int getLength() {
		return _lengthWidth;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Endianess getEndianess() {
		return _endianess;
	}

	/**
	 * Returns the allocated length in bytes declared by this instance.
	 * 
	 * @return The allocated length in bytes.
	 */
	@Override
	public int getAllocLength() {
		return _allocLength;
	}

	/**
	 * Provides means to manipulate the length of a transmission in terms of
	 * {@link #toTransmission()} and
	 * {@link #transmitTo(OutputStream, InputStream)} (or the like sending
	 * operations).
	 * 
	 * CAUTION: The provided allocation length gets overwritten as soon as a
	 * transmission is being received in terms of
	 * {@link #fromTransmission(Sequence)} (or the like receiving operations)!
	 * 
	 * This method is meant to manipulate the number of bytes to be sent from a
	 * buffer (a buffer such as a {@link SequenceSection} might reserve a given
	 * number of bytes to be manipulated, though not all of them are to be
	 * sent).
	 *
	 * @return the schema
	 */
	//	@Override
	//	public void setAllocLength( int aAllocLength ) {
	//		_allocLength = aAllocLength;
	//	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void reset() {
		_referencee.reset();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public SerialSchema toSchema() {
		final SerialSchema theSchema = new SerialSchema( getClass(), toSequence(), Integer.toString( getAllocLength() ), "An allocation value referencing a segment which's length is to be allocated and allocating that length in bytes.", getLength() );
		theSchema.put( ENDIANESS, _endianess );
		theSchema.put( ALLOC_LENGTH_WIDTH, _lengthWidth );
		theSchema.put( ALLOC_LENGTH, _allocLength );
		return theSchema;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public int hashCode() {
		return Objects.hash( _referencee, _endianess, _lengthWidth, _allocLength );
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean equals( Object obj ) {
		if ( this == obj ) {
			return true;
		}
		if ( !( obj instanceof AbstractReferenceeLengthSegment ) ) {
			return false;
		}
		final AbstractReferenceeLengthSegment other = (AbstractReferenceeLengthSegment) obj;
		return Objects.equals( _referencee, other._referencee ) && _endianess == other._endianess && _lengthWidth == other._lengthWidth && _allocLength == other._allocLength;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public String toString() {
		return getClass().getSimpleName() + " [endianess=" + _endianess + ", lengthWidth=" + _lengthWidth + ", value=" + _allocLength + "]";
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public SimpleTypeMap toSimpleTypeMap() {
		return _referencee != null ? _referencee.toSimpleTypeMap() : new SimpleTypeMapImpl();
	}
}