/***
* 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.tajo.tuple.memory;
import org.apache.tajo.common.TajoDataTypes.DataType;
import org.apache.tajo.tuple.RowBlockReader;
public class HeapRowBlockReader implements RowBlockReader<HeapTuple> {
private final DataType[] dataTypes;
private final MemoryBlock memoryBlock;
private final int rows;
// Read States
private int curRowIdxForRead;
private int curPosForRead;
public HeapRowBlockReader(MemoryRowBlock rowBlock) {
this(rowBlock.getMemory(), rowBlock.getDataTypes(), rowBlock.rows());
}
public HeapRowBlockReader(MemoryBlock memoryBlock, DataType[] dataTypes, int rows) {
this.dataTypes = dataTypes;
this.rows = rows;
this.memoryBlock = memoryBlock.duplicate();
}
public long remainForRead() {
return memoryBlock.readableBytes();
}
@Override
public boolean next(HeapTuple tuple) {
if (curRowIdxForRead < rows) {
tuple.set(memoryBlock, curPosForRead, dataTypes);
curPosForRead += tuple.getLength();
curRowIdxForRead++;
memoryBlock.readerPosition(curPosForRead);
return true;
} else {
return false;
}
}
@Override
public void reset() {
curPosForRead = 0;
curRowIdxForRead = 0;
memoryBlock.readerPosition(curPosForRead);
}
}