/**
 * 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 edu.uci.ics.hivesterix.serde.lazy;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;

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

/**
 * LazyObject stores an object in a range of bytes in a byte[].
 * 
 * A LazyObject can represent any primitive object or hierarchical object like
 * array, map or struct.
 */
public abstract class LazyObject<OI extends ObjectInspector> {

	OI oi;

	/**
	 * Create a LazyObject.
	 * 
	 * @param oi
	 *            Derived classes can access meta information about this Lazy
	 *            Object (e.g, separator, nullSequence, escaper) from it.
	 */
	protected LazyObject(OI oi) {
		this.oi = oi;
	}

	/**
	 * Set the data for this LazyObject. We take ByteArrayRef instead of byte[]
	 * so that we will be able to drop the reference to byte[] by a single
	 * assignment. The ByteArrayRef object can be reused across multiple rows.
	 * 
	 * @param bytes
	 *            The wrapper of the byte[].
	 * @param start
	 *            The start position inside the bytes.
	 * @param length
	 *            The length of the data, starting from "start"
	 * @see ByteArrayRef
	 */
	public abstract void init(byte[] bytes, int start, int length);

	public abstract void init(IFrameTupleReference tuple);

	/**
	 * If the LazyObject is a primitive Object, then deserialize it and return
	 * the actual primitive Object. Otherwise (array, map, struct), return this.
	 */
	public abstract Object getObject();

	@Override
	public abstract int hashCode();

	protected OI getInspector() {
		return oi;
	}

	protected void setInspector(OI oi) {
		this.oi = oi;
	}
}