content: /*
   * 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.kafka.streams.state.internals;
  
  /**
   * This class was taken from Hive org.apache.hive.common.util;
   * https://github.com/apache/hive/blob/master/storage-api/src/java/org/apache/hive/common/util/Murmur3.java
   * Commit: dffa3a16588bc8e95b9d0ab5af295a74e06ef702
   *
   *
   * Murmur3 is successor to Murmur2 fast non-crytographic hash algorithms.
   *
   * Murmur3 32 and 128 bit variants.
   * 32-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#94
   * 128-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#255
   *
   * This is a public domain code with no copyrights.
   * From homepage of MurmurHash (https://code.google.com/p/smhasher/),
   * "All MurmurHash versions are public domain software, and the author disclaims all copyright
   * to their code."
   */
  @SuppressWarnings("fallthrough")
  public class Murmur3 {
      // from 64-bit linear congruential generator
      public static final long NULL_HASHCODE = 2862933555777941757L;
  
      // Constants for 32 bit variant
      private static final int C1_32 = 0xcc9e2d51;
      private static final int C2_32 = 0x1b873593;
      private static final int R1_32 = 15;
      private static final int R2_32 = 13;
      private static final int M_32 = 5;
      private static final int N_32 = 0xe6546b64;
  
      // Constants for 128 bit variant
      private static final long C1 = 0x87c37b91114253d5L;
      private static final long C2 = 0x4cf5ad432745937fL;
      private static final int R1 = 31;
      private static final int R2 = 27;
      private static final int R3 = 33;
      private static final int M = 5;
      private static final int N1 = 0x52dce729;
      private static final int N2 = 0x38495ab5;
  
      public static final int DEFAULT_SEED = 104729;
  
      public static int hash32(long l0, long l1) {
          return hash32(l0, l1, DEFAULT_SEED);
      }
  
      public static int hash32(long l0) {
          return hash32(l0, DEFAULT_SEED);
      }
  
      /**
       * Murmur3 32-bit variant.
       */
      public static int hash32(long l0, int seed) {
          int hash = seed;
          final long r0 = Long.reverseBytes(l0);
  
          hash = mix32((int) r0, hash);
          hash = mix32((int) (r0 >>> 32), hash);
  
          return fmix32(Long.BYTES, hash);
      }
  
      /**
       * Murmur3 32-bit variant.
       */
      public static int hash32(long l0, long l1, int seed) {
          int hash = seed;
          final long r0 = Long.reverseBytes(l0);
          final long r1 = Long.reverseBytes(l1);
  
          hash = mix32((int) r0, hash);
          hash = mix32((int) (r0 >>> 32), hash);
          hash = mix32((int) (r1), hash);
          hash = mix32((int) (r1 >>> 32), hash);
  
          return fmix32(Long.BYTES * 2, hash);
      }
  
      /**
       * Murmur3 32-bit variant.
       *
       * @param data - input byte array
       * @return - hashcode
       */
      public static int hash32(byte[] data) {
          return hash32(data, 0, data.length, DEFAULT_SEED);
      }
  
      /**
       * Murmur3 32-bit variant.
       *
       * @param data - input byte array
       * @param length - length of array
       * @return - hashcode
       */
      public static int hash32(byte[] data, int length) {
          return hash32(data, 0, length, DEFAULT_SEED);
      }
  
      /**
       * Murmur3 32-bit variant.
       *
       * @param data   - input byte array
       * @param length - length of array
       * @param seed   - seed. (default 0)
       * @return - hashcode
       */
      public static int hash32(byte[] data, int length, int seed) {
          return hash32(data, 0, length, seed);
      }
  
      /**
       * Murmur3 32-bit variant.
       *
       * @param data   - input byte array
       * @param offset - offset of data
       * @param length - length of array
       * @param seed   - seed. (default 0)
       * @return - hashcode
       */
      public static int hash32(byte[] data, int offset, int length, int seed) {
          int hash = seed;
          final int nblocks = length >> 2;
  
          // body
          for (int i = 0; i < nblocks; i++) {
              int i_4 = i << 2;
              int k = (data[offset + i_4] & 0xff)
                      | ((data[offset + i_4 + 1] & 0xff) << 8)
                      | ((data[offset + i_4 + 2] & 0xff) << 16)
                      | ((data[offset + i_4 + 3] & 0xff) << 24);
  
              hash = mix32(k, hash);
          }
  
          // tail
          int idx = nblocks << 2;
          int k1 = 0;
          switch (length - idx) {
              case 3:
                  k1 ^= data[offset + idx + 2] << 16;
              case 2:
                  k1 ^= data[offset + idx + 1] << 8;
              case 1:
                  k1 ^= data[offset + idx];
  
                  // mix functions
                  k1 *= C1_32;
                  k1 = Integer.rotateLeft(k1, R1_32);
                  k1 *= C2_32;
                  hash ^= k1;
          }
  
          return fmix32(length, hash);
      }
  
      private static int mix32(int k, int hash) {
          k *= C1_32;
          k = Integer.rotateLeft(k, R1_32);
          k *= C2_32;
          hash ^= k;
          return Integer.rotateLeft(hash, R2_32) * M_32 + N_32;
      }
  
      private static int fmix32(int length, int hash) {
          hash ^= length;
          hash ^= (hash >>> 16);
          hash *= 0x85ebca6b;
          hash ^= (hash >>> 13);
          hash *= 0xc2b2ae35;
          hash ^= (hash >>> 16);
  
          return hash;
      }
  
      /**
       * Murmur3 64-bit variant. This is essentially MSB 8 bytes of Murmur3 128-bit variant.
       *
       * @param data - input byte array
       * @return - hashcode
       */
      public static long hash64(byte[] data) {
          return hash64(data, 0, data.length, DEFAULT_SEED);
      }
  
      public static long hash64(long data) {
          long hash = DEFAULT_SEED;
          long k = Long.reverseBytes(data);
          int length = Long.BYTES;
          // mix functions
          k *= C1;
          k = Long.rotateLeft(k, R1);
          k *= C2;
          hash ^= k;
          hash = Long.rotateLeft(hash, R2) * M + N1;
          // finalization
          hash ^= length;
          hash = fmix64(hash);
          return hash;
      }
  
      public static long hash64(int data) {
          long k1 = Integer.reverseBytes(data) & (-1L >>> 32);
          int length = Integer.BYTES;
          long hash = DEFAULT_SEED;
          k1 *= C1;
          k1 = Long.rotateLeft(k1, R1);
          k1 *= C2;
          hash ^= k1;
          // finalization
          hash ^= length;
          hash = fmix64(hash);
          return hash;
      }
  
      public static long hash64(short data) {
          long hash = DEFAULT_SEED;
          long k1 = 0;
          k1 ^= ((long) data & 0xff) << 8;
          k1 ^= ((long)((data & 0xFF00) >> 8) & 0xff);
          k1 *= C1;
          k1 = Long.rotateLeft(k1, R1);
          k1 *= C2;
          hash ^= k1;
  
          // finalization
          hash ^= Short.BYTES;
          hash = fmix64(hash);
          return hash;
      }
  
      public static long hash64(byte[] data, int offset, int length) {
          return hash64(data, offset, length, DEFAULT_SEED);
      }
  
      /**
       * Murmur3 64-bit variant. This is essentially MSB 8 bytes of Murmur3 128-bit variant.
       *
       * @param data   - input byte array
       * @param length - length of array
       * @param seed   - seed. (default is 0)
       * @return - hashcode
       */
      public static long hash64(byte[] data, int offset, int length, int seed) {
          long hash = seed;
          final int nblocks = length >> 3;
  
          // body
          for (int i = 0; i < nblocks; i++) {
              final int i8 = i << 3;
              long k = ((long) data[offset + i8] & 0xff)
                      | (((long) data[offset + i8 + 1] & 0xff) << 8)
                      | (((long) data[offset + i8 + 2] & 0xff) << 16)
                      | (((long) data[offset + i8 + 3] & 0xff) << 24)
                      | (((long) data[offset + i8 + 4] & 0xff) << 32)
                      | (((long) data[offset + i8 + 5] & 0xff) << 40)
                      | (((long) data[offset + i8 + 6] & 0xff) << 48)
                      | (((long) data[offset + i8 + 7] & 0xff) << 56);
  
              // mix functions
              k *= C1;
              k = Long.rotateLeft(k, R1);
              k *= C2;
              hash ^= k;
              hash = Long.rotateLeft(hash, R2) * M + N1;
          }
  
          // tail
          long k1 = 0;
          int tailStart = nblocks << 3;
          switch (length - tailStart) {
              case 7:
                  k1 ^= ((long) data[offset + tailStart + 6] & 0xff) << 48;
              case 6:
                  k1 ^= ((long) data[offset + tailStart + 5] & 0xff) << 40;
              case 5:
                  k1 ^= ((long) data[offset + tailStart + 4] & 0xff) << 32;
              case 4:
                  k1 ^= ((long) data[offset + tailStart + 3] & 0xff) << 24;
              case 3:
                  k1 ^= ((long) data[offset + tailStart + 2] & 0xff) << 16;
              case 2:
                  k1 ^= ((long) data[offset + tailStart + 1] & 0xff) << 8;
              case 1:
                  k1 ^= ((long) data[offset + tailStart] & 0xff);
                  k1 *= C1;
                  k1 = Long.rotateLeft(k1, R1);
                  k1 *= C2;
                  hash ^= k1;
          }
  
          // finalization
          hash ^= length;
          hash = fmix64(hash);
  
          return hash;
      }
  
      /**
       * Murmur3 128-bit variant.
       *
       * @param data - input byte array
       * @return - hashcode (2 longs)
       */
      public static long[] hash128(byte[] data) {
          return hash128(data, 0, data.length, DEFAULT_SEED);
      }
  
      /**
       * Murmur3 128-bit variant.
       *
       * @param data   - input byte array
       * @param offset - the first element of array
       * @param length - length of array
       * @param seed   - seed. (default is 0)
       * @return - hashcode (2 longs)
       */
      public static long[] hash128(byte[] data, int offset, int length, int seed) {
          long h1 = seed;
          long h2 = seed;
          final int nblocks = length >> 4;
  
          // body
          for (int i = 0; i < nblocks; i++) {
              final int i16 = i << 4;
              long k1 = ((long) data[offset + i16] & 0xff)
                      | (((long) data[offset + i16 + 1] & 0xff) << 8)
                      | (((long) data[offset + i16 + 2] & 0xff) << 16)
                      | (((long) data[offset + i16 + 3] & 0xff) << 24)
                      | (((long) data[offset + i16 + 4] & 0xff) << 32)
                      | (((long) data[offset + i16 + 5] & 0xff) << 40)
                      | (((long) data[offset + i16 + 6] & 0xff) << 48)
                      | (((long) data[offset + i16 + 7] & 0xff) << 56);
  
              long k2 = ((long) data[offset + i16 + 8] & 0xff)
                      | (((long) data[offset + i16 + 9] & 0xff) << 8)
                      | (((long) data[offset + i16 + 10] & 0xff) << 16)
                      | (((long) data[offset + i16 + 11] & 0xff) << 24)
                      | (((long) data[offset + i16 + 12] & 0xff) << 32)
                      | (((long) data[offset + i16 + 13] & 0xff) << 40)
                      | (((long) data[offset + i16 + 14] & 0xff) << 48)
                      | (((long) data[offset + i16 + 15] & 0xff) << 56);
  
              // mix functions for k1
              k1 *= C1;
              k1 = Long.rotateLeft(k1, R1);
              k1 *= C2;
              h1 ^= k1;
              h1 = Long.rotateLeft(h1, R2);
              h1 += h2;
              h1 = h1 * M + N1;
  
              // mix functions for k2
              k2 *= C2;
              k2 = Long.rotateLeft(k2, R3);
              k2 *= C1;
              h2 ^= k2;
              h2 = Long.rotateLeft(h2, R1);
              h2 += h1;
              h2 = h2 * M + N2;
          }
  
          // tail
          long k1 = 0;
          long k2 = 0;
          int tailStart = nblocks << 4;
          switch (length - tailStart) {
              case 15:
                  k2 ^= (long) (data[offset + tailStart + 14] & 0xff) << 48;
              case 14:
                  k2 ^= (long) (data[offset + tailStart + 13] & 0xff) << 40;
              case 13:
                  k2 ^= (long) (data[offset + tailStart + 12] & 0xff) << 32;
              case 12:
                  k2 ^= (long) (data[offset + tailStart + 11] & 0xff) << 24;
              case 11:
                  k2 ^= (long) (data[offset + tailStart + 10] & 0xff) << 16;
              case 10:
                  k2 ^= (long) (data[offset + tailStart + 9] & 0xff) << 8;
              case 9:
                  k2 ^= (long) (data[offset + tailStart + 8] & 0xff);
                  k2 *= C2;
                  k2 = Long.rotateLeft(k2, R3);
                  k2 *= C1;
                  h2 ^= k2;
  
              case 8:
                  k1 ^= (long) (data[offset + tailStart + 7] & 0xff) << 56;
              case 7:
                  k1 ^= (long) (data[offset + tailStart + 6] & 0xff) << 48;
              case 6:
                  k1 ^= (long) (data[offset + tailStart + 5] & 0xff) << 40;
              case 5:
                  k1 ^= (long) (data[offset + tailStart + 4] & 0xff) << 32;
              case 4:
                  k1 ^= (long) (data[offset + tailStart + 3] & 0xff) << 24;
              case 3:
                  k1 ^= (long) (data[offset + tailStart + 2] & 0xff) << 16;
              case 2:
                  k1 ^= (long) (data[offset + tailStart + 1] & 0xff) << 8;
              case 1:
                  k1 ^= (long) (data[offset + tailStart] & 0xff);
                  k1 *= C1;
                  k1 = Long.rotateLeft(k1, R1);
                  k1 *= C2;
                  h1 ^= k1;
          }
  
          // finalization
          h1 ^= length;
          h2 ^= length;
  
          h1 += h2;
          h2 += h1;
  
          h1 = fmix64(h1);
          h2 = fmix64(h2);
  
          h1 += h2;
          h2 += h1;
  
          return new long[]{h1, h2};
      }
  
      private static long fmix64(long h) {
          h ^= (h >>> 33);
          h *= 0xff51afd7ed558ccdL;
          h ^= (h >>> 33);
          h *= 0xc4ceb9fe1a85ec53L;
          h ^= (h >>> 33);
          return h;
      }
  
      public static class IncrementalHash32 {
          byte[] tail = new byte[3];
          int tailLen;
          int totalLen;
          int hash;
  
          public final void start(int hash) {
              tailLen = totalLen = 0;
              this.hash = hash;
          }
  
          public final void add(byte[] data, int offset, int length) {
              if (length == 0) return;
              totalLen += length;
              if (tailLen + length < 4) {
                  System.arraycopy(data, offset, tail, tailLen, length);
                  tailLen += length;
                  return;
              }
              int offset2 = 0;
              if (tailLen > 0) {
                  offset2 = (4 - tailLen);
                  int k = -1;
                  switch (tailLen) {
                      case 1:
                          k = orBytes(tail[0], data[offset], data[offset + 1], data[offset + 2]);
                          break;
                      case 2:
                          k = orBytes(tail[0], tail[1], data[offset], data[offset + 1]);
                          break;
                      case 3:
                          k = orBytes(tail[0], tail[1], tail[2], data[offset]);
                          break;
                      default: throw new AssertionError(tailLen);
                  }
                  // mix functions
                  k *= C1_32;
                  k = Integer.rotateLeft(k, R1_32);
                  k *= C2_32;
                  hash ^= k;
                  hash = Integer.rotateLeft(hash, R2_32) * M_32 + N_32;
              }
              int length2 = length - offset2;
              offset += offset2;
              final int nblocks = length2 >> 2;
  
              for (int i = 0; i < nblocks; i++) {
                  int i_4 = (i << 2) + offset;
                  int k = orBytes(data[i_4], data[i_4 + 1], data[i_4 + 2], data[i_4 + 3]);
  
                  // mix functions
                  k *= C1_32;
                  k = Integer.rotateLeft(k, R1_32);
                  k *= C2_32;
                  hash ^= k;
                  hash = Integer.rotateLeft(hash, R2_32) * M_32 + N_32;
              }
  
              int consumed = (nblocks << 2);
              tailLen = length2 - consumed;
              if (consumed == length2) return;
              System.arraycopy(data, offset + consumed, tail, 0, tailLen);
          }
  
          public final int end() {
              int k1 = 0;
              switch (tailLen) {
                  case 3:
                      k1 ^= tail[2] << 16;
                  case 2:
                      k1 ^= tail[1] << 8;
                  case 1:
                      k1 ^= tail[0];
  
                      // mix functions
                      k1 *= C1_32;
                      k1 = Integer.rotateLeft(k1, R1_32);
                      k1 *= C2_32;
                      hash ^= k1;
              }
  
              // finalization
              hash ^= totalLen;
              hash ^= (hash >>> 16);
              hash *= 0x85ebca6b;
              hash ^= (hash >>> 13);
              hash *= 0xc2b2ae35;
              hash ^= (hash >>> 16);
              return hash;
          }
      }
  
      private static int orBytes(byte b1, byte b2, byte b3, byte b4) {
          return (b1 & 0xff) | ((b2 & 0xff) << 8) | ((b3 & 0xff) << 16) | ((b4 & 0xff) << 24);
      }
  }
  