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/**
* Copyright 2004-2006 DFKI GmbH.
* All Rights Reserved. Use is subject to license terms.
*
* Permission is hereby granted, free of charge, to use and distribute
* this software and its documentation without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of this work, and to
* permit persons to whom this work is furnished to do so, subject to
* the following conditions:
*
* 1. The code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
* 2. Any modifications must be clearly marked as such.
* 3. Original authors' names are not deleted.
* 4. The authors' names are not used to endorse or promote products
* derived from this software without specific prior written
* permission.
*
* DFKI GMBH AND THE CONTRIBUTORS TO THIS WORK DISCLAIM ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DFKI GMBH NOR THE
* CONTRIBUTORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
* THIS SOFTWARE.
*/
package de.dfki.lt.signalproc.util;
// TODO: Auto-generated Javadoc
/**
* The Class BaseDoubleDataSource.
*
* @author Marc Schröder
*/
public class BaseDoubleDataSource implements DoubleDataSource
{
/** The input source. */
protected DoubleDataSource inputSource = null;
/** The data length. */
protected long dataLength = DoubleDataSource.NOT_SPECIFIED;
/**
* Instantiates a new base double data source.
*/
public BaseDoubleDataSource()
{
}
/**
* Instantiates a new base double data source.
*
* @param inputSource the input source
*/
public BaseDoubleDataSource(DoubleDataSource inputSource) {
this.inputSource = inputSource;
if (inputSource != null)
dataLength = inputSource.getDataLength();
}
/**
* Request to get the specified amount of data in a new double array.
* @param amount the number of doubles requested
* @return a new double array; its length may be smaller than amount if not
* enough data could be obtained. If no data could be read, null is returned.
*/
public double[] getData(int amount)
{
if (amount <= 0)
throw new IllegalArgumentException("amount must be positive");
double[] container = new double[amount];
int received = getData(container);
if (received == 0) {
return null;
} else if (received < amount) {
double[] newContainer = new double[received];
System.arraycopy(container, 0, newContainer, 0, received);
return newContainer;
} else {
return container;
}
}
/**
* Try to get as many double data from this DoubleDataSource as target can hold.
* @param target the double array in which to write the data
* @return the number of data items written into target. If the returned value is less than target.length,
* only that many data items have been copied into target; further calls will return 0 and not copy anything.
*/
public int getData(double[] target) {
return getData(target, 0, target.length);
}
/**
* Try to get length doubles from this DoubleDataSource, and copy them into target, starting from targetPos.
* This is the core method getting the data. Subclasses may want to override this method.
*
* @param target the double array to write into
* @param targetPos position in target where to start writing
* @param length the amount of data requested
* @return the amount of data actually delivered. If the returned value is less than length,
* only that many data items have been copied into target; further calls will return 0 and not copy anything.
*/
public int getData(double[] target, int targetPos, int length)
{
if (target.length - targetPos < length) {
throw new IllegalArgumentException("Target array cannot hold enough data ("+(target.length-targetPos) + " left, but " + length + " requested)");
}
if (inputSource == null) return 0;
return inputSource.getData(target, targetPos, length);
}
/**
* Whether or not any more data can be read from this data source.
* @return true if another call to getData() will return data, false otherwise.
*/
public boolean hasMoreData()
{
if (inputSource == null) return false;
return inputSource.hasMoreData();
}
/**
* The number of doubles that can currently be read from this
* double data source without blocking. This number can change over time.
* @return the number of doubles that can currently be read without blocking
*/
public int available()
{
if (inputSource == null) return 0;
return inputSource.available();
}
/**
* Get all the data that can be read from this data source, in a single
* double array.
*
* @return a double array of exactly the length required to contain all the data
* that can be read from this source. Returns an array of length 0 if no data can be
* read from this source.
*/
public double[] getAllData()
{
double[] all = new double[BufferedDoubleDataSource.DEFAULT_BUFFERSIZE];
int currentPos = 0;
while (hasMoreData()) {
int nRead = getData(all, currentPos, all.length-currentPos);
if (nRead < all.length-currentPos) {
// done
assert !hasMoreData();
currentPos += nRead;
break; // leave while loop
} else {
assert currentPos + nRead == all.length;
double[] newAll = new double[2*all.length];
System.arraycopy(all, 0, newAll, 0, all.length);
currentPos = all.length;
all = newAll;
}
}
double[] result = new double[currentPos];
System.arraycopy(all, 0, result, 0, currentPos);
return result;
}
/**
* Get the total length of the data in this data source, if available. For a
* BufferedDoubleDataSource created from a double[], the data length is available.
* @return the number of doubles that can be read from this data source, or
* DoubleDataSource.NOT_SPECIFIED if unknown.
*/
public long getDataLength()
{
return dataLength;
}
}