// This software is released into the Public Domain. See copying.txt for details.
package org.openstreetmap.osmosis.pbf2.v0_6.impl;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.util.Iterator;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.openstreetmap.osmosis.core.OsmosisRuntimeException;
import org.openstreetmap.osmosis.core.lifecycle.Releasable;
import org.openstreetmap.osmosis.osmbinary.Fileformat;
import org.openstreetmap.osmosis.osmbinary.Fileformat.BlobHeader;
/**
* Parses a PBF data stream and extracts the raw data of each blob in sequence
* until the end of the stream is reached.
*
* @author Brett Henderson
*/
public class PbfStreamSplitter implements Iterator<PbfRawBlob>, Releasable {
private static Logger log = Logger.getLogger(PbfStreamSplitter.class.getName());
private DataInputStream dis;
private int dataBlockCount;
private boolean eof;
private PbfRawBlob nextBlob;
/**
* Creates a new instance.
*
* @param pbfStream
* The PBF data stream to be parsed.
*/
public PbfStreamSplitter(DataInputStream pbfStream) {
dis = pbfStream;
dataBlockCount = 0;
eof = false;
}
private BlobHeader readHeader(int headerLength) throws IOException {
byte[] headerBuffer = new byte[headerLength];
dis.readFully(headerBuffer);
BlobHeader blobHeader = Fileformat.BlobHeader.parseFrom(headerBuffer);
return blobHeader;
}
private byte[] readRawBlob(BlobHeader blobHeader) throws IOException {
byte[] rawBlob = new byte[blobHeader.getDatasize()];
dis.readFully(rawBlob);
return rawBlob;
}
private void getNextBlob() {
try {
// Read the length of the next header block. This is the only time
// we should expect to encounter an EOF exception. In all other
// cases it indicates a corrupt or truncated file.
int headerLength;
try {
headerLength = dis.readInt();
} catch (EOFException e) {
eof = true;
return;
}
if (log.isLoggable(Level.FINER)) {
log.finer("Reading header for blob " + dataBlockCount++);
}
BlobHeader blobHeader = readHeader(headerLength);
if (log.isLoggable(Level.FINER)) {
log.finer("Processing blob of type " + blobHeader.getType() + ".");
}
byte[] blobData = readRawBlob(blobHeader);
nextBlob = new PbfRawBlob(blobHeader.getType(), blobData);
} catch (IOException e) {
throw new OsmosisRuntimeException("Unable to get next blob from PBF stream.", e);
}
}
@Override
public boolean hasNext() {
if (nextBlob == null && !eof) {
getNextBlob();
}
return nextBlob != null;
}
@Override
public PbfRawBlob next() {
PbfRawBlob result = nextBlob;
nextBlob = null;
return result;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public void release() {
if (dis != null) {
try {
dis.close();
} catch (IOException e) {
log.log(Level.SEVERE, "Unable to close PBF stream.", e);
}
}
dis = null;
}
}