/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.codec;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.Cell;
public abstract class BaseDecoder implements Codec.Decoder {
protected static final Log LOG = LogFactory.getLog(BaseDecoder.class);
protected final InputStream in;
private boolean hasNext = true;
private Cell current = null;
public BaseDecoder(final InputStream in) {
this.in = in;
}
@Override
public boolean advance() throws IOException {
if (!this.hasNext) return this.hasNext;
if (this.in.available() == 0) {
this.hasNext = false;
return this.hasNext;
}
try {
this.current = parseCell();
} catch (IOException ioEx) {
rethrowEofException(ioEx);
}
return this.hasNext;
}
private void rethrowEofException(IOException ioEx) throws IOException {
boolean isEof = false;
try {
isEof = this.in.available() == 0;
} catch (Throwable t) {
LOG.trace("Error getting available for error message - ignoring", t);
}
if (!isEof) throw ioEx;
LOG.error("Partial cell read caused by EOF: " + ioEx);
EOFException eofEx = new EOFException("Partial cell read");
eofEx.initCause(ioEx);
throw eofEx;
}
/**
* @return extract a Cell
* @throws IOException
*/
protected abstract Cell parseCell() throws IOException;
@Override
public Cell current() {
return this.current;
}
}