package com.bigdata.bfs;
import java.io.DataInput;
import java.io.IOException;
import java.io.InputStream;
import com.bigdata.btree.IOverflowHandler;
import com.bigdata.btree.ITuple;
import com.bigdata.btree.keys.IKeyBuilder;
import com.bigdata.btree.keys.KeyBuilder;
import com.bigdata.io.DataOutputBuffer;
import com.bigdata.rawstore.IBlock;
import com.bigdata.rawstore.IRawStore;
import com.bigdata.util.Bytes;
/**
* Copies blocks onto the target store during overflow handling. Blocks that
* are no longer referenced by the file data index will be left behind on
* the journal and eventually discarded with the journal.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class BlobOverflowHandler implements IOverflowHandler {
/**
*
*/
private static final long serialVersionUID = -8180664203349900189L;
/**
* De-serialization constructor.
*/
public BlobOverflowHandler() {
}
private transient DataOutputBuffer buf;
public void close() {
buf = null;
}
public byte[] handle(final ITuple tuple, final IRawStore target) {
if (buf == null) {
buf = new DataOutputBuffer();
}
final long addr;
try {
DataInput in = tuple.getValueStream();
addr = in.readLong();
} catch (IOException e) {
throw new RuntimeException(e);
}
final IKeyBuilder keyBuilder = new KeyBuilder(Bytes.SIZEOF_LONG);
if (addr == 0L) {
/*
* Note: empty blocks are allowed and are recorded with 0L as
* their address.
*/
return keyBuilder.append(0L).getKey();
}
// read block from underlying source store.
final IBlock block = tuple.readBlock(addr);
// #of bytes in the block.
final int len = block.length();
// make sure buffer has sufficient capacity.
buf.ensureCapacity(len);
// prepare buffer for write.
buf.reset();
final InputStream bin = block.inputStream();
// // the address on which the block will be written.
// final long addr2 = block2.getAddress();
final long addr2;
try {
// // #of bytes read so far.
// long n = 0;
//
// while (len - n > 0) {
// read source into buffer.
final int nread = bin.read(buf.array(), 0, len);
if (nread != len) {
throw new RuntimeException("Premature end of block: expected="
+ len + ", actual=" + nread);
}
// write on the target store.
addr2 = target.write(buf.asByteBuffer());
// // write buffer onto sink.
// bout.write(buf, 0, nread);
// n += nread;
//
// }
// bout.flush();
} catch (IOException ex) {
BigdataFileSystem.log.warn("Problem copying block: addr=" + addr
+ ", len=" + len, ex);
throw new RuntimeException(ex);
} finally {
// try {
// bout.close();
// } catch (IOException ex) {
// log.warn(ex);
// }
try {
bin.close();
} catch (IOException ex) {
BigdataFileSystem.log.warn(ex);
}
}
// the address of the block on the target store.
return keyBuilder.append(addr2).getKey();
}
}