/*
 * 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.data.std.collections.api;

/**
 * Represents an immutable vector of ValueReferences. Users of this interface make the assumption
 * that it provides random access to the items in it. In other words, each of the getXXX(index) calls
 * have O(1) complexity.
 * 
 * @author vinayakb
 */
public interface IValueReferenceVector {
    /**
     * Number of items in this vector.
     * 
     * @return - the number of items in this vector.
     */
    public int getSize();

    /**
     * Get the byte array that contains the item referenced by <code>index</code>
     * 
     * @param index
     *            - Index of the item in the vector
     * @return Byte Array that contains the item.
     */
    public byte[] getBytes(int index);

    /**
     * Get the start offset of the item referenced by <code>index</code>
     * 
     * @param index
     *            - Index of the item in the vector
     * @return Start Offset in the Byte Array of the item
     */
    public int getStart(int index);

    /**
     * Get the length of the item referenced by <code>index</code>
     * 
     * @param index
     *            - Index of the item in the vector
     * @return Length in the Byte Array of the item
     */
    public int getLength(int index);
}