/*
    * 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.util;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  /**
   * A set of array utility functions that return reasonable values in cases where an array is
   * allocated or if it is null
   */
  @InterfaceAudience.Private
  public class ArrayUtils {
  
    public static int length(byte[] a) {
      if (a == null) {
        return 0;
      }
      return a.length;
    }
  
    public static int length(long[] a) {
      if (a == null) {
        return 0;
      }
      return a.length;
    }
  
    public static int length(Object[] a) {
      if (a == null) {
        return 0;
      }
      return a.length;
    }
  
    public static boolean isEmpty(byte[] a) {
      if (a == null) {
        return true;
      }
      if (a.length == 0) {
        return true;
      }
      return false;
    }
  
    public static boolean isEmpty(long[] a) {
      if (a == null) {
        return true;
      }
      if (a.length == 0) {
        return true;
      }
      return false;
    }
  
    public static boolean isEmpty(Object[] a) {
      if (a == null) {
        return true;
      }
      if (a.length == 0) {
        return true;
      }
      return false;
    }
  
    public static long getFirst(long[] a) {
      return a[0];
    }
  
    public static long getLast(long[] a) {
      return a[a.length - 1];
    }
  
    public static int getTotalLengthOfArrays(Iterable<byte[]> arrays) {
      if (arrays == null) {
        return 0;
      }
      int length = 0;
      for (byte[] bytes : arrays) {
        length += length(bytes);
      }
     return length;
   }
 
   public static ArrayList<Long> toList(long[] array){
     int length = length(array);
     ArrayList<Long> list = new ArrayList<Long>(length);
     for(int i=0; i < length; ++i){
       list.add(array[i]);
     }
     return list;
   }
 
   public static byte[] growIfNecessary(byte[] array, int minLength, int numAdditionalBytes) {
     if(array.length >= minLength){
       return array;
     }
     return Arrays.copyOf(array, minLength + numAdditionalBytes);
   }
 
   public static int[] growIfNecessary(int[] array, int minLength, int numAdditionalInts) {
     if(array.length >= minLength){
       return array;
     }
     return Arrays.copyOf(array, minLength + numAdditionalInts);
   }
 
   public static long[] growIfNecessary(long[] array, int minLength, int numAdditionalLongs) {
     if(array.length >= minLength){
       return array;
     }
     return Arrays.copyOf(array, minLength + numAdditionalLongs);
   }
 
 }