ExtendedWKBReader.java

/*
 * The JTS Topology Suite is a collection of Java classes that
 * implement the fundamental operations required to validate a given
 * geo-spatial data set to a known topological specification.
 *
 * Copyright (C) 2001 Vivid Solutions
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For more information, contact:
 *
 *     Vivid Solutions
 *     Suite #1A
 *     2328 Government Street
 *     Victoria BC  V8T 5G5
 *     Canada
 *
 *     (250)385-6040
 *     www.vividsolutions.com
 */

package eu.esdihumboldt.hale.common.instance.orient.internal;

import java.io.IOException;

import com.vividsolutions.jts.geom.CoordinateSequence;
import com.vividsolutions.jts.geom.CoordinateSequenceFactory;
import com.vividsolutions.jts.geom.CoordinateSequences;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.MultiLineString;
import com.vividsolutions.jts.geom.MultiPoint;
import com.vividsolutions.jts.geom.MultiPolygon;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.geom.PrecisionModel;
import com.vividsolutions.jts.io.ByteArrayInStream;
import com.vividsolutions.jts.io.ByteOrderDataInStream;
import com.vividsolutions.jts.io.ByteOrderValues;
import com.vividsolutions.jts.io.InStream;
import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKBConstants;
import com.vividsolutions.jts.io.WKBReader;

/**
 * Extended version of {@link WKBReader}, that differentiates between
 * {@link LinearRing}s and {@link LineString}s.
 */
public class ExtendedWKBReader {

	/**
	 * Converts a hexadecimal string to a byte array. The hexadecimal digit
	 * symbols are case-insensitive.
	 * 
	 * @param hex a string containing hex digits
	 * @return an array of bytes with the value of the hex string
	 */
	public static byte[] hexToBytes(String hex) {
		int byteLen = hex.length() / 2;
		byte[] bytes = new byte[byteLen];

		for (int i = 0; i < hex.length() / 2; i++) {
			int i2 = 2 * i;
			if (i2 + 1 > hex.length())
				throw new IllegalArgumentException("Hex string has odd length");

			int nib1 = hexToInt(hex.charAt(i2));
			int nib0 = hexToInt(hex.charAt(i2 + 1));
			byte b = (byte) ((nib1 << 4) + (byte) nib0);
			bytes[i] = b;
		}
		return bytes;
	}

	private static int hexToInt(char hex) {
		int nib = Character.digit(hex, 16);
		if (nib < 0)
			throw new IllegalArgumentException("Invalid hex digit: '" + hex + "'");
		return nib;
	}

	private static final String INVALID_GEOM_TYPE_MSG = "Invalid geometry type encountered in ";

	private GeometryFactory factory;
	private CoordinateSequenceFactory csFactory;
	private PrecisionModel precisionModel;
	// default dimension - will be set on read
	private int inputDimension = 2;
	private boolean hasSRID = false;
//	private int SRID = 0;
	private boolean isRepairRings = false;
	private ByteOrderDataInStream dis = new ByteOrderDataInStream();
	private double[] ordValues;

	/**
	 * Default constructor
	 */
	public ExtendedWKBReader() {
		this(new GeometryFactory());
	}

	/**
	 * Create an extended WKB reader with the given geometry factory.
	 * 
	 * @param geometryFactory the geometry factory
	 */
	public ExtendedWKBReader(GeometryFactory geometryFactory) {
		this.factory = geometryFactory;
		precisionModel = factory.getPrecisionModel();
		csFactory = factory.getCoordinateSequenceFactory();
	}

	/**
	 * Reads a single {@link Geometry} in WKB format from a byte array.
	 * 
	 * @param bytes the byte array to read from
	 * @return the geometry read
	 * @throws ParseException if the WKB is ill-formed
	 */
	public Geometry read(byte[] bytes) throws ParseException {
		// possibly reuse the ByteArrayInStream?
		// don't throw IOExceptions, since we are not doing any I/O
		try {
			return read(new ByteArrayInStream(bytes));
		} catch (IOException ex) {
			throw new RuntimeException("Unexpected IOException caught: " + ex.getMessage());
		}
	}

	/**
	 * Reads a {@link Geometry} in binary WKB format from an {@link InStream}.
	 * 
	 * @param is the stream to read from
	 * @return the Geometry read
	 * @throws IOException if the underlying stream creates an error
	 * @throws ParseException if the WKB is ill-formed
	 */
	public Geometry read(InStream is) throws IOException, ParseException {
		dis.setInStream(is);
		Geometry g = readGeometry();
		return g;
	}

	private Geometry readGeometry() throws IOException, ParseException {
		// determine byte order
		byte byteOrder = dis.readByte();
		// default is big endian
		if (byteOrder == WKBConstants.wkbNDR)
			dis.setOrder(ByteOrderValues.LITTLE_ENDIAN);

		int typeInt = dis.readInt();
		int geometryType = typeInt & 0xff;
		// determine if Z values are present
		boolean hasZ = (typeInt & 0x80000000) != 0;
		inputDimension = hasZ ? 3 : 2;
		// determine if SRIDs are present
		hasSRID = (typeInt & 0x20000000) != 0;

		int SRID = 0;
		if (hasSRID) {
			SRID = dis.readInt();
		}

		// only allocate ordValues buffer if necessary
		if (ordValues == null || ordValues.length < inputDimension)
			ordValues = new double[inputDimension];

		Geometry geom = null;
		switch (geometryType) {
		// XXX start addendum
		case ExtendedWKBWriter.wkbLinearRing:
			geom = readLinearRing();
			break;
		// XXX end addendum
		case WKBConstants.wkbPoint:
			geom = readPoint();
			break;
		case WKBConstants.wkbLineString:
			geom = readLineString();
			break;
		case WKBConstants.wkbPolygon:
			geom = readPolygon();
			break;
		case WKBConstants.wkbMultiPoint:
			geom = readMultiPoint();
			break;
		case WKBConstants.wkbMultiLineString:
			geom = readMultiLineString();
			break;
		case WKBConstants.wkbMultiPolygon:
			geom = readMultiPolygon();
			break;
		case WKBConstants.wkbGeometryCollection:
			geom = readGeometryCollection();
			break;
		default:
			throw new ParseException("Unknown WKB type " + geometryType);
		}
		setSRID(geom, SRID);
		return geom;
	}

	/**
	 * Sets the SRID, if it was specified in the WKB
	 * 
	 * @param g the geometry to update
	 * @param SRID the SRID value
	 * @return the geometry with an updated SRID value, if required
	 */
	private Geometry setSRID(Geometry g, int SRID) {
		if (SRID != 0)
			g.setSRID(SRID);
		return g;
	}

	private Point readPoint() throws IOException {
		CoordinateSequence pts = readCoordinateSequence(1);
		return factory.createPoint(pts);
	}

	private LineString readLineString() throws IOException {
		int size = dis.readInt();
		CoordinateSequence pts = readCoordinateSequence(size);
		return factory.createLineString(pts);
	}

	private LinearRing readLinearRing() throws IOException {
		int size = dis.readInt();
		CoordinateSequence pts = readCoordinateSequenceRing(size);
		return factory.createLinearRing(pts);
	}

	@SuppressWarnings("null")
	private Polygon readPolygon() throws IOException {
		int numRings = dis.readInt();
		LinearRing[] holes = null;
		if (numRings > 1)
			holes = new LinearRing[numRings - 1];

		LinearRing shell = readLinearRing();
		for (int i = 0; i < numRings - 1; i++) {
			holes[i] = readLinearRing();
		}
		return factory.createPolygon(shell, holes);
	}

	private MultiPoint readMultiPoint() throws IOException, ParseException {
		int numGeom = dis.readInt();
		Point[] geoms = new Point[numGeom];
		for (int i = 0; i < numGeom; i++) {
			Geometry g = readGeometry();
			if (!(g instanceof Point))
				throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiPoint");
			geoms[i] = (Point) g;
		}
		return factory.createMultiPoint(geoms);
	}

	private MultiLineString readMultiLineString() throws IOException, ParseException {
		int numGeom = dis.readInt();
		LineString[] geoms = new LineString[numGeom];
		for (int i = 0; i < numGeom; i++) {
			Geometry g = readGeometry();
			if (!(g instanceof LineString))
				throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiLineString");
			geoms[i] = (LineString) g;
		}
		return factory.createMultiLineString(geoms);
	}

	private MultiPolygon readMultiPolygon() throws IOException, ParseException {
		int numGeom = dis.readInt();
		Polygon[] geoms = new Polygon[numGeom];
		for (int i = 0; i < numGeom; i++) {
			Geometry g = readGeometry();
			if (!(g instanceof Polygon))
				throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiPolygon");
			geoms[i] = (Polygon) g;
		}
		return factory.createMultiPolygon(geoms);
	}

	private GeometryCollection readGeometryCollection() throws IOException, ParseException {
		int numGeom = dis.readInt();
		Geometry[] geoms = new Geometry[numGeom];
		for (int i = 0; i < numGeom; i++) {
			geoms[i] = readGeometry();
		}
		return factory.createGeometryCollection(geoms);
	}

	private CoordinateSequence readCoordinateSequence(int size) throws IOException {
		CoordinateSequence seq = csFactory.create(size, inputDimension);
		int targetDim = seq.getDimension();
		if (targetDim > inputDimension)
			targetDim = inputDimension;
		for (int i = 0; i < size; i++) {
			readCoordinate();
			for (int j = 0; j < targetDim; j++) {
				seq.setOrdinate(i, j, ordValues[j]);
			}
		}
		return seq;
	}

	private CoordinateSequence readCoordinateSequenceRing(int size) throws IOException {
		CoordinateSequence seq = readCoordinateSequence(size);
		if (!isRepairRings)
			return seq;
		if (CoordinateSequences.isRing(seq))
			return seq;
		return CoordinateSequences.ensureValidRing(csFactory, seq);
	}

	/**
	 * Reads a coordinate value with the specified dimensionality. Makes the X
	 * and Y ordinates precise according to the precision model in use.
	 * 
	 * @throws IOException if an error occurs reading the coordinate
	 */
	private void readCoordinate() throws IOException {
		for (int i = 0; i < inputDimension; i++) {
			if (i <= 1) {
				ordValues[i] = precisionModel.makePrecise(dis.readDouble());
			}
			else {
				ordValues[i] = dis.readDouble();
			}

		}
	}

}