/*
* Copyright 1998-2014 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
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* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA 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 ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.nc2.iosp;
import ucar.ma2.InvalidRangeException;
import ucar.ma2.Section;
import java.io.IOException;
import java.nio.*;
/**
* For datasets where the data are stored in chunks, and must be processed, eg compressed or filtered.
* The data is read, processed, and placed in a ByteBuffer. Chunks have an offset into the ByteBuffer.
* "Tiled" means that all chunks are assumed to be equal size.
* Chunks do not necessarily cover the array, missing data is possible.
*
* @author caron
* @since Jan 9, 2008
*/
public class LayoutBBTiled implements LayoutBB {
private Section want;
private int[] chunkSize; // all chunks assumed to be the same size
private int elemSize;
private DataChunkIterator chunkIterator; // iterate across chunks
private IndexChunkerTiled index = null; // iterate within a chunk
// track the overall iteration
private long totalNelems, totalNelemsDone; // total number of elemens
private static final boolean debug = false, debugIntersection = false;
/**
* Constructor.
*
* @param chunkIterator iterator over all data chunks
* @param chunkSize all chunks assumed to be the same size
* @param elemSize size of an element in bytes.
* @param wantSection the wanted section of data, contains a List of Range objects. Must be complete.
* @throws ucar.ma2.InvalidRangeException if section invalid for this variable
* @throws java.io.IOException on io error
*/
public LayoutBBTiled(DataChunkIterator chunkIterator, int[] chunkSize, int elemSize, Section wantSection) throws InvalidRangeException, IOException {
this.chunkIterator = chunkIterator;
this.chunkSize = chunkSize;
this.elemSize = elemSize;
this.want = wantSection;
if (debug) System.out.println(" want section="+this.want);
this.totalNelems = this.want.computeSize();
this.totalNelemsDone = 0;
}
public long getTotalNelems() {
return totalNelems;
}
public int getElemSize() {
return elemSize;
}
private LayoutBBTiled.Chunk next;
public boolean hasNext() { // have to actually fetch the thing
if (totalNelemsDone >= totalNelems) return false;
if ((index == null) || !index.hasNext()) { // get new data node
try {
Section dataSection;
DataChunk dataChunk;
while (true) { // look for intersecting sections
if (!chunkIterator.hasNext()) {
next = null;
return false;
}
// get next dataChunk
try {
dataChunk = chunkIterator.next();
} catch (IOException e) {
e.printStackTrace();
next = null;
return false;
}
// make the dataSection for this chunk
dataSection = new Section(dataChunk.getOffset(), chunkSize);
if (debugIntersection)
System.out.println(" test intersecting: " + dataSection + " want: " + want);
if (dataSection.intersects(want)) // does it intersect ?
break;
}
if (debug)
System.out.println(" found intersecting dataSection: " + dataSection+" intersect= "+dataSection.intersect(want));
index = new IndexChunkerTiled(dataSection, want); // new indexer into this chunk
next = new Chunk( dataChunk.getByteBuffer()); // this does the uncompression
} catch (InvalidRangeException e) {
throw new IllegalStateException(e);
} catch (IOException e) {
throw new IllegalStateException(e);
}
}
IndexChunker.Chunk chunk = index.next();
totalNelemsDone += chunk.getNelems();
next.setDelegate( chunk);
return true;
}
public LayoutBB.Chunk next() throws IOException {
return next;
}
public String toString() {
StringBuilder sbuff = new StringBuilder();
sbuff.append("want=").append(want).append("; ");
sbuff.append("chunkSize=[");
for (int i = 0; i < chunkSize.length; i++) {
if (i > 0) sbuff.append(",");
sbuff.append(chunkSize[i]);
}
sbuff.append("] totalNelems=").append(totalNelems);
sbuff.append(" elemSize=").append(elemSize);
return sbuff.toString();
}
/**
* An iterator over the data chunks.
*/
static public interface DataChunkIterator {
public boolean hasNext();
public DataChunk next() throws IOException;
}
/**
* A data chunk
*/
static public interface DataChunk {
public int[] getOffset();
public ByteBuffer getByteBuffer() throws IOException;
}
/**
* A chunk of data that is contiguous in both the source and destination.
* Everything is done in elements, not bytes.
* Read nelems from src at srcPos, store in destination at destPos.
*/
static private class Chunk implements LayoutBB.Chunk {
IndexChunker.Chunk delegate;
private ByteBuffer bb;
private ShortBuffer sb;
private IntBuffer ib;
private LongBuffer longb;
private FloatBuffer fb;
private DoubleBuffer db;
Chunk(ByteBuffer bb) {
this.bb = bb;
}
public void setDelegate(IndexChunker.Chunk delegate) {
this.delegate = delegate;
}
public int getSrcElem() {
return (int) delegate.getSrcElem();
}
public int getNelems() {
return delegate.getNelems();
}
public long getDestElem() {
return delegate.getDestElem();
}
public ByteBuffer getByteBuffer() {
return bb;
}
public ShortBuffer getShortBuffer() {
if (sb == null) sb = bb.asShortBuffer();
return sb;
}
public IntBuffer getIntBuffer() {
if (ib == null) ib = bb.asIntBuffer();
return ib;
}
public LongBuffer getLongBuffer() {
if (longb == null) longb = bb.asLongBuffer();
return longb;
}
public FloatBuffer getFloatBuffer() {
if (fb == null) fb = bb.asFloatBuffer();
return fb;
}
public DoubleBuffer getDoubleBuffer() {
if (db == null) db = bb.asDoubleBuffer();
return db;
}
@Override
public String toString() {
return delegate.toString();
}
// artifact of overriding Layout
public long getSrcPos(){
throw new UnsupportedOperationException();
}
}
}