content: /*
   * Copyright (C) 2015 The Android Open Source Project
   *
   * 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 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 android.security.keystore;
  
  import libcore.util.EmptyArray;
  
  /**
   * @hide
   */
  public abstract class ArrayUtils {
      private ArrayUtils() {}
  
      public static String[] nullToEmpty(String[] array) {
          return (array != null) ? array : EmptyArray.STRING;
      }
  
      public static String[] cloneIfNotEmpty(String[] array) {
          return ((array != null) && (array.length > 0)) ? array.clone() : array;
      }
  
      public static byte[] cloneIfNotEmpty(byte[] array) {
          return ((array != null) && (array.length > 0)) ? array.clone() : array;
      }
  
      public static byte[] concat(byte[] arr1, byte[] arr2) {
          return concat(arr1, 0, (arr1 != null) ? arr1.length : 0,
                  arr2, 0, (arr2 != null) ? arr2.length : 0);
      }
  
      public static byte[] concat(byte[] arr1, int offset1, int len1, byte[] arr2, int offset2,
              int len2) {
          if (len1 == 0) {
              return subarray(arr2, offset2, len2);
          } else if (len2 == 0) {
              return subarray(arr1, offset1, len1);
          } else {
              byte[] result = new byte[len1 + len2];
              System.arraycopy(arr1, offset1, result, 0, len1);
              System.arraycopy(arr2, offset2, result, len1, len2);
              return result;
          }
      }
  
      public static byte[] subarray(byte[] arr, int offset, int len) {
          if (len == 0) {
              return EmptyArray.BYTE;
          }
          if ((offset == 0) && (len == arr.length)) {
              return arr;
          }
          byte[] result = new byte[len];
          System.arraycopy(arr, offset, result, 0, len);
          return result;
      }
  
      public static int[] concat(int[] arr1, int[] arr2) {
          if ((arr1 == null) || (arr1.length == 0)) {
              return arr2;
          } else if ((arr2 == null) || (arr2.length == 0)) {
              return arr1;
          } else {
              int[] result = new int[arr1.length + arr2.length];
              System.arraycopy(arr1, 0, result, 0, arr1.length);
              System.arraycopy(arr2, 0, result, arr1.length, arr2.length);
              return result;
          }
      }
  }
  