content: /*
   * Copyright (C) 2016 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 com.google.android.exoplayer2.upstream.crypto;
  
  /**
   * Utility functions for the crypto package.
   */
  /* package */ final class CryptoUtil {
  
    private CryptoUtil() {}
  
    /**
     * Returns the hash value of the input as a long using the 64 bit FNV-1a hash function. The hash
     * values produced by this function are less likely to collide than those produced by
     * {@link #hashCode()}.
     */
    public static long getFNV64Hash(String input) {
      if (input == null) {
        return 0;
      }
  
      long hash = 0;
      for (int i = 0; i < input.length(); i++) {
        hash ^= input.charAt(i);
        // This is equivalent to hash *= 0x100000001b3 (the FNV magic prime number).
        hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) + (hash << 8) + (hash << 40);
      }
      return hash;
    }
  
  }
  