org.h2.store.LobStorageRemoteInputStream Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.store;
import java.io.IOException;
import java.io.InputStream;
import org.h2.message.DbException;
import org.h2.value.ValueLobDb;
/**
* An input stream that reads from a remote LOB.
*/
class LobStorageRemoteInputStream extends InputStream {
/**
* The data handler.
*/
private final DataHandler handler;
/**
* The lob id.
*/
private final long lob;
private final byte[] hmac;
/**
* The position.
*/
private long pos;
/**
* The remaining bytes in the lob.
*/
private long remainingBytes;
public LobStorageRemoteInputStream(DataHandler handler, ValueLobDb lob,
byte[] hmac, long byteCount) {
this.handler = handler;
this.lob = lob.getLobId();
this.hmac = hmac;
remainingBytes = byteCount;
}
@Override
public int read() throws IOException {
byte[] buff = new byte[1];
int len = read(buff, 0, 1);
return len < 0 ? len : (buff[0] & 255);
}
@Override
public int read(byte[] buff) throws IOException {
return read(buff, 0, buff.length);
}
@Override
public int read(byte[] buff, int off, int length) throws IOException {
if (length == 0) {
return 0;
}
length = (int) Math.min(length, remainingBytes);
if (length == 0) {
return -1;
}
try {
length = handler.readLob(lob, hmac, pos, buff, off, length);
} catch (DbException e) {
throw DbException.convertToIOException(e);
}
if (length == 0) {
return -1;
}
remainingBytes -= length;
pos += length;
return length;
}
@Override
public long skip(long n) {
remainingBytes -= n;
pos += n;
return n;
}
}