/*
 * Copyright 2009-2010 by The Regents of the University of California
 * Licensed 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 from
 * 
 *     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 edu.uci.ics.hyracks.storage.am.common.tuples;

import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;

public class PermutingFrameTupleReference implements IFrameTupleReference {
	private IFrameTupleAccessor fta;
	private int tIndex;
	private int[] fieldPermutation;

	public void setFieldPermutation(int[] fieldPermutation) {
		this.fieldPermutation = fieldPermutation;
	}

	public void reset(IFrameTupleAccessor fta, int tIndex) {
		this.fta = fta;
		this.tIndex = tIndex;
	}

	@Override
	public IFrameTupleAccessor getFrameTupleAccessor() {
		return fta;
	}

	@Override
	public int getTupleIndex() {
		return tIndex;
	}

	@Override
	public int getFieldCount() {
		return fieldPermutation.length;
	}

	@Override
	public byte[] getFieldData(int fIdx) {
		return fta.getBuffer().array();
	}

	@Override
	public int getFieldStart(int fIdx) {
		return fta.getTupleStartOffset(tIndex) + fta.getFieldSlotsLength()
				+ fta.getFieldStartOffset(tIndex, fieldPermutation[fIdx]);
	}

	@Override
	public int getFieldLength(int fIdx) {
		return fta.getFieldLength(tIndex, fieldPermutation[fIdx]);
	}
}