text: // MurmurHash3 was written by Austin Appleby, and is placed in the public
  // domain. The author hereby disclaims copyright to this source code.
  
  // Copyright (c) 2013 Baidu, Inc.
  // Compute murmurhash3 iteratively so that you don't have to buffer
  // everything in memory before computation. The APIs are similar with MD5
  
  // Note - The x86 and x64 versions do _not_ produce the same results, as the
  // algorithms are optimized for their respective platforms. You can still
  // compile and run any of them on any platform, but your performance with the
  // non-native version will be less than optimal.
  
  #include <stddef.h>  // size_t
  #include <string.h>  // memcpy
  #include <algorithm> // std::min
  #include "butil/third_party/murmurhash3/murmurhash3.h"
  
  // Too many fallthroughs in this file to mark, just ignore the warning.
  #if defined(__GNUC__) && __GNUC__ >= 7
  #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
  #endif
  
  //-----------------------------------------------------------------------------
  // Platform-specific functions and macros
  
  // Microsoft Visual Studio
  
  #if defined(_MSC_VER)
  
  #include <stdlib.h>
  
  #define ROTL32(x,y) _rotl(x,y)
  #define ROTL64(x,y) _rotl64(x,y)
  
  // Other compilers
  
  #else   // defined(_MSC_VER)
  
  inline uint32_t rotl32 ( uint32_t x, int8_t r )
  {
    return (x << r) | (x >> (32 - r));
  }
  
  inline uint64_t rotl64 ( uint64_t x, int8_t r )
  {
    return (x << r) | (x >> (64 - r));
  }
  
  #define ROTL32(x,y) rotl32(x,y)
  #define ROTL64(x,y) rotl64(x,y)
  
  #endif // !defined(_MSC_VER)
  
  namespace butil {
  //-----------------------------------------------------------------------------
  // Block read - if your platform needs to do endian-swapping or can only
  // handle aligned reads, do the conversion here
  
  MURMURHASH_FORCE_INLINE uint32_t getblock32 ( const uint32_t * p, int i ) {
    return p[i];
  }
  
  MURMURHASH_FORCE_INLINE uint64_t getblock64 ( const uint64_t * p, int i ) {
    return p[i];
  }
  
  //-----------------------------------------------------------------------------
  
  void MurmurHash3_x86_32 ( const void * key, int len,
                            uint32_t seed, void * out ) {
    const uint8_t * data = (const uint8_t*)key;
    const int nblocks = len / 4;
  
    uint32_t h1 = seed;
  
    const uint32_t c1 = 0xcc9e2d51;
    const uint32_t c2 = 0x1b873593;
  
    //----------
    // body
  
    const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
  
    for(int i = -nblocks; i; i++)
    {
      uint32_t k1 = getblock32(blocks,i);
  
      k1 *= c1;
      k1 = ROTL32(k1,15);
      k1 *= c2;
      
      h1 ^= k1;
      h1 = ROTL32(h1,13); 
      h1 = h1*5+0xe6546b64;
    }
  
    //----------
    // tail
  
    const uint8_t * tail = (const uint8_t*)(data + nblocks*4);
  
    uint32_t k1 = 0;
  
    switch(len & 3)
    {
    case 3: k1 ^= tail[2] << 16;
    case 2: k1 ^= tail[1] << 8;
    case 1: k1 ^= tail[0];
            k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
    };
  
    //----------
    // finalization
  
    h1 ^= len;
  
    h1 = fmix32(h1);
  
    *(uint32_t*)out = h1;
  } 
  
  //-----------------------------------------------------------------------------
  
  void MurmurHash3_x86_128 ( const void * key, const int len,
                             uint32_t seed, void * out ) {
    const uint8_t * data = (const uint8_t*)key;
    const int nblocks = len / 16;
  
    uint32_t h1 = seed;
    uint32_t h2 = seed;
    uint32_t h3 = seed;
    uint32_t h4 = seed;
  
    const uint32_t c1 = 0x239b961b; 
    const uint32_t c2 = 0xab0e9789;
    const uint32_t c3 = 0x38b34ae5; 
    const uint32_t c4 = 0xa1e38b93;
  
    //----------
    // body
  
    const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
  
    for(int i = -nblocks; i; i++)
    {
      uint32_t k1 = getblock32(blocks,i*4+0);
      uint32_t k2 = getblock32(blocks,i*4+1);
      uint32_t k3 = getblock32(blocks,i*4+2);
      uint32_t k4 = getblock32(blocks,i*4+3);
  
      k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
  
      h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
  
      k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
  
      h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
  
      k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
  
      h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
  
      k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
  
      h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
    }
  
    //----------
    // tail
  
    const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
  
    uint32_t k1 = 0;
    uint32_t k2 = 0;
    uint32_t k3 = 0;
    uint32_t k4 = 0;
  
    switch(len & 15)
    {
    case 15: k4 ^= tail[14] << 16;
    case 14: k4 ^= tail[13] << 8;
    case 13: k4 ^= tail[12] << 0;
             k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
  
    case 12: k3 ^= tail[11] << 24;
    case 11: k3 ^= tail[10] << 16;
    case 10: k3 ^= tail[ 9] << 8;
    case  9: k3 ^= tail[ 8] << 0;
             k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
  
    case  8: k2 ^= tail[ 7] << 24;
    case  7: k2 ^= tail[ 6] << 16;
    case  6: k2 ^= tail[ 5] << 8;
    case  5: k2 ^= tail[ 4] << 0;
             k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
  
    case  4: k1 ^= tail[ 3] << 24;
    case  3: k1 ^= tail[ 2] << 16;
    case  2: k1 ^= tail[ 1] << 8;
    case  1: k1 ^= tail[ 0] << 0;
             k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
    };
  
    //----------
    // finalization
  
    h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
  
    h1 += h2; h1 += h3; h1 += h4;
    h2 += h1; h3 += h1; h4 += h1;
  
    h1 = fmix32(h1);
    h2 = fmix32(h2);
    h3 = fmix32(h3);
    h4 = fmix32(h4);
  
    h1 += h2; h1 += h3; h1 += h4;
    h2 += h1; h3 += h1; h4 += h1;
  
    ((uint32_t*)out)[0] = h1;
    ((uint32_t*)out)[1] = h2;
    ((uint32_t*)out)[2] = h3;
    ((uint32_t*)out)[3] = h4;
  }
  
  //-----------------------------------------------------------------------------
  
  void MurmurHash3_x64_128 ( const void * key, const int len,
                             const uint32_t seed, void * out ) {
    const uint8_t * data = (const uint8_t*)key;
    const int nblocks = len / 16;
  
    uint64_t h1 = seed;
    uint64_t h2 = seed;
  
    const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
    const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
  
    //----------
    // body
  
    const uint64_t * blocks = (const uint64_t *)(data);
  
    for(int i = 0; i < nblocks; i++)
    {
      uint64_t k1 = getblock64(blocks,i*2+0);
      uint64_t k2 = getblock64(blocks,i*2+1);
  
      k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
  
      h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
  
      k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
  
      h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
    }
  
    //----------
    // tail
  
    const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
  
    uint64_t k1 = 0;
    uint64_t k2 = 0;
  
    switch(len & 15)
    {
    case 15: k2 ^= ((uint64_t)tail[14]) << 48;
    case 14: k2 ^= ((uint64_t)tail[13]) << 40;
    case 13: k2 ^= ((uint64_t)tail[12]) << 32;
    case 12: k2 ^= ((uint64_t)tail[11]) << 24;
    case 11: k2 ^= ((uint64_t)tail[10]) << 16;
    case 10: k2 ^= ((uint64_t)tail[ 9]) << 8;
    case  9: k2 ^= ((uint64_t)tail[ 8]) << 0;
             k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
  
    case  8: k1 ^= ((uint64_t)tail[ 7]) << 56;
    case  7: k1 ^= ((uint64_t)tail[ 6]) << 48;
    case  6: k1 ^= ((uint64_t)tail[ 5]) << 40;
    case  5: k1 ^= ((uint64_t)tail[ 4]) << 32;
    case  4: k1 ^= ((uint64_t)tail[ 3]) << 24;
    case  3: k1 ^= ((uint64_t)tail[ 2]) << 16;
    case  2: k1 ^= ((uint64_t)tail[ 1]) << 8;
    case  1: k1 ^= ((uint64_t)tail[ 0]) << 0;
             k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
    };
  
    //----------
    // finalization
  
    h1 ^= len; h2 ^= len;
  
    h1 += h2;
    h2 += h1;
  
    h1 = fmix64(h1);
    h2 = fmix64(h2);
  
    h1 += h2;
    h2 += h1;
  
    ((uint64_t*)out)[0] = h1;
    ((uint64_t*)out)[1] = h2;
  }
  
  // ============= iterative versions ==================
  
  namespace murmurhash3 {
  static const size_t FAST_MEMCPY_MAXSIZE = 123;
  template <size_t size> struct FastMemcpyBlock {
      int data[size];
  };
  template <> struct FastMemcpyBlock<0> { };
  
  template <size_t size> class FastMemcpy {
  public:
      typedef FastMemcpyBlock<size / sizeof(int)> Block;
  
      static void* copy(void *dest, const void *src) {
          *(Block*)dest = *(Block*)src;
          if ((size % sizeof(int)) > 2) {
              ((char*)dest)[size-3] = ((char*)src)[size-3];
          }
          if ((size % sizeof(int)) > 1) {
              ((char*)dest)[size-2] = ((char*)src)[size-2];
          }
          if ((size % sizeof(int)) > 0) {
              ((char*)dest)[size-1] = ((char*)src)[size-1];
          }
          return dest;
      }
  };
  
  typedef void* (*CopyFn)(void*, const void*);
  static CopyFn s_fast_memcpy_fn[FAST_MEMCPY_MAXSIZE + 1];
  
  template <size_t size>
  struct InitFastMemcpy : public InitFastMemcpy<size-1> {
      InitFastMemcpy() {
          s_fast_memcpy_fn[size] = FastMemcpy<size>::copy;
      }
  };
  template <>
  class InitFastMemcpy<0> {
  public:
      InitFastMemcpy() {
          s_fast_memcpy_fn[0] = FastMemcpy<0>::copy;
      }
  };
  inline void* cp(void *__restrict dest, const void *__restrict src, size_t n) {
  #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
      // memcpy in gcc 4.8 seems to be faster.
      return memcpy(dest, src, n);
  #else
      if (n <= FAST_MEMCPY_MAXSIZE) {
          static InitFastMemcpy<FAST_MEMCPY_MAXSIZE> _init_cp_dummy;
          return s_fast_memcpy_fn[n](dest, src);
      }
      return memcpy(dest, src, n);
  #endif
  }
  } // namespace murmurhash3
  
  void MurmurHash3_x86_128_Init(MurmurHash3_x86_128_Context* ctx, uint32_t seed)
  {
      ctx->h1 = seed;
      ctx->h2 = seed;
      ctx->h3 = seed;
      ctx->h4 = seed;
      ctx->total_len = 0;
      ctx->tail_len = 0;
  }
  
  void MurmurHash3_x86_128_Update(
      MurmurHash3_x86_128_Context* ctx, const void * key, int len)
  {
      const uint8_t * data = (const uint8_t*)key;
  
      uint32_t h1 = ctx->h1;
      uint32_t h2 = ctx->h2;
      uint32_t h3 = ctx->h3;
      uint32_t h4 = ctx->h4;
  
      const uint32_t c1 = 0x239b961b; 
      const uint32_t c2 = 0xab0e9789;
      const uint32_t c3 = 0x38b34ae5; 
      const uint32_t c4 = 0xa1e38b93;
  
      if (ctx->tail_len > 0) {
          const int append = std::min(len, 16 - ctx->tail_len);
          murmurhash3::cp(ctx->tail + ctx->tail_len, data, append);
          ctx->total_len += append;
          ctx->tail_len += append;
          data += append;
          len -= append;
          if (ctx->tail_len == 16) {
              uint32_t k1 = getblock32((uint32_t*)ctx->tail, 0);
              uint32_t k2 = getblock32((uint32_t*)ctx->tail, 1);
              uint32_t k3 = getblock32((uint32_t*)ctx->tail, 2);
              uint32_t k4 = getblock32((uint32_t*)ctx->tail, 3);
  
              k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
  
              h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
  
              k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
  
              h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
  
              k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
  
              h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
  
              k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
  
              h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
  
              ctx->tail_len = 0;
          }
      }
  
      const int nblocks = len / 16;
  
      //----------
      // body
  
      const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
  
      for (int i = -nblocks; i; i++)
      {
          uint32_t k1 = getblock32(blocks,i*4+0);
          uint32_t k2 = getblock32(blocks,i*4+1);
          uint32_t k3 = getblock32(blocks,i*4+2);
          uint32_t k4 = getblock32(blocks,i*4+3);
  
          k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
  
          h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
  
          k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
  
          h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
  
          k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
  
          h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
  
          k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
  
          h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
      }
  
      //----------
      // tail
  
      const int tail_len = len & 15;
      if (tail_len > 0) {
          murmurhash3::cp(ctx->tail, data + nblocks * 16, tail_len);
          ctx->tail_len = tail_len;
      }
      ctx->h1 = h1;
      ctx->h2 = h2;
      ctx->h3 = h3;
      ctx->h4 = h4;
      ctx->total_len += len;
  }
  
  void MurmurHash3_x86_128_Final(void * out, const MurmurHash3_x86_128_Context* ctx)
  {
      uint32_t h1 = ctx->h1;
      uint32_t h2 = ctx->h2;
      uint32_t h3 = ctx->h3;
      uint32_t h4 = ctx->h4;
      const int len = ctx->total_len;
  
      const uint8_t * tail = ctx->tail;
  
      const uint32_t c1 = 0x239b961b; 
      const uint32_t c2 = 0xab0e9789;
      const uint32_t c3 = 0x38b34ae5; 
      const uint32_t c4 = 0xa1e38b93;
  
      uint32_t k1 = 0;
      uint32_t k2 = 0;
      uint32_t k3 = 0;
      uint32_t k4 = 0;
  
      switch (ctx->tail_len)
      {
      case 15: k4 ^= tail[14] << 16;
      case 14: k4 ^= tail[13] << 8;
      case 13: k4 ^= tail[12] << 0;
          k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
  
      case 12: k3 ^= tail[11] << 24;
      case 11: k3 ^= tail[10] << 16;
      case 10: k3 ^= tail[ 9] << 8;
      case  9: k3 ^= tail[ 8] << 0;
          k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
  
      case  8: k2 ^= tail[ 7] << 24;
      case  7: k2 ^= tail[ 6] << 16;
      case  6: k2 ^= tail[ 5] << 8;
      case  5: k2 ^= tail[ 4] << 0;
          k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
  
      case  4: k1 ^= tail[ 3] << 24;
      case  3: k1 ^= tail[ 2] << 16;
      case  2: k1 ^= tail[ 1] << 8;
      case  1: k1 ^= tail[ 0] << 0;
          k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
      };
  
  
      //----------
      // finalization
  
      h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
  
      h1 += h2; h1 += h3; h1 += h4;
      h2 += h1; h3 += h1; h4 += h1;
  
      h1 = fmix32(h1);
      h2 = fmix32(h2);
      h3 = fmix32(h3);
      h4 = fmix32(h4);
  
      h1 += h2; h1 += h3; h1 += h4;
      h2 += h1; h3 += h1; h4 += h1;
  
      ((uint32_t*)out)[0] = h1;
      ((uint32_t*)out)[1] = h2;
      ((uint32_t*)out)[2] = h3;
      ((uint32_t*)out)[3] = h4;
  }
  
  //-----------------------------------------------------------------------------
  
  void MurmurHash3_x64_128_Init(MurmurHash3_x64_128_Context* ctx, uint32_t seed)
  {
      ctx->h1 = seed;
      ctx->h2 = seed;
      ctx->total_len = 0;
      ctx->tail_len = 0;
  }
  
  void MurmurHash3_x64_128_Update(
      MurmurHash3_x64_128_Context* ctx, const void * key, int len)
  {
      uint64_t h1 = ctx->h1;
      uint64_t h2 = ctx->h2;
  
      const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
      const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
  
      const uint8_t * data = (const uint8_t*)key;
      if (ctx->tail_len > 0) {
          const int append = std::min(len, 16 - ctx->tail_len);
          murmurhash3::cp(ctx->tail + ctx->tail_len, data, append);
          ctx->total_len += append;
          ctx->tail_len += append;
          data += append;
          len -= append;
          if (ctx->tail_len == 16) {
              uint64_t k1 = getblock64((uint64_t*)ctx->tail, 0);
              uint64_t k2 = getblock64((uint64_t*)ctx->tail, 1);
  
              k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
  
              h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
  
              k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
  
              h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
              ctx->tail_len = 0;
          }
      }
  
      const int nblocks = len / 16;
  
      //----------
      // body
  
      const uint64_t * blocks = (const uint64_t *)(data);
  
      for (int i = 0; i < nblocks; i++)
      {
          uint64_t k1 = getblock64(blocks,i*2+0);
          uint64_t k2 = getblock64(blocks,i*2+1);
  
          k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
  
          h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
  
          k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
  
          h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
      }
  
      // tail
      const int tail_len = len & 15;
      if (tail_len > 0) {
          murmurhash3::cp(ctx->tail, data + nblocks * 16, tail_len);
          ctx->tail_len = tail_len;
      }
  
      ctx->h1 = h1;
      ctx->h2 = h2;
      ctx->total_len += len;
  }
  
  void MurmurHash3_x64_128_Final(void * out, const MurmurHash3_x64_128_Context* ctx)
  {
      uint64_t h1 = ctx->h1;
      uint64_t h2 = ctx->h2;
      const uint64_t len = ctx->total_len;
      //----------
      // tail
  
      const uint8_t * tail = ctx->tail;
      const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
      const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
  
      uint64_t k1 = 0;
      uint64_t k2 = 0;
  
      switch (ctx->tail_len)
      {
      case 15: k2 ^= ((uint64_t)tail[14]) << 48;
      case 14: k2 ^= ((uint64_t)tail[13]) << 40;
      case 13: k2 ^= ((uint64_t)tail[12]) << 32;
      case 12: k2 ^= ((uint64_t)tail[11]) << 24;
      case 11: k2 ^= ((uint64_t)tail[10]) << 16;
      case 10: k2 ^= ((uint64_t)tail[ 9]) << 8;
      case  9: k2 ^= ((uint64_t)tail[ 8]) << 0;
          k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
  
      case  8: k1 ^= ((uint64_t)tail[ 7]) << 56;
      case  7: k1 ^= ((uint64_t)tail[ 6]) << 48;
      case  6: k1 ^= ((uint64_t)tail[ 5]) << 40;
      case  5: k1 ^= ((uint64_t)tail[ 4]) << 32;
      case  4: k1 ^= ((uint64_t)tail[ 3]) << 24;
      case  3: k1 ^= ((uint64_t)tail[ 2]) << 16;
      case  2: k1 ^= ((uint64_t)tail[ 1]) << 8;
      case  1: k1 ^= ((uint64_t)tail[ 0]) << 0;
          k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
      };
  
  
      //----------
      // finalization
  
      h1 ^= len; h2 ^= len;
  
      h1 += h2;
      h2 += h1;
  
      h1 = fmix64(h1);
      h2 = fmix64(h2);
  
      h1 += h2;
      h2 += h1;
  
      ((uint64_t*)out)[0] = h1;
      ((uint64_t*)out)[1] = h2;
  }
  
  void MurmurHash3_x86_32_Init(MurmurHash3_x86_32_Context* ctx, uint32_t seed) {
      ctx->h1 = seed;
      ctx->total_len = 0;
      ctx->tail_len = 0;
  }
  
  void MurmurHash3_x86_32_Update(MurmurHash3_x86_32_Context* ctx, const void* key, int len) {
      
      uint32_t h1 = ctx->h1;
      const uint32_t c1 = 0xcc9e2d51;
      const uint32_t c2 = 0x1b873593;
      const uint8_t * data = (const uint8_t*)key;
      if (ctx->tail_len > 0) {
          const int append = std::min(len, 4 - ctx->tail_len);
          murmurhash3::cp(ctx->tail + ctx->tail_len, data, append);
          ctx->total_len += append;
          ctx->tail_len += append;
          data += append;
          len -= append;
          if (ctx->tail_len == 4) {
              uint32_t k1 = getblock32((uint32_t*)ctx->tail,0);
  
              k1 *= c1;
              k1 = ROTL32(k1,15);
              k1 *= c2;
  
              h1 ^= k1;
              h1 = ROTL32(h1,13); 
              h1 = h1*5+0xe6546b64;
              ctx->tail_len = 0;
          }
      }
  
      const int nblocks = len / 4;
  
      //----------
      // body
  
      const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
  
      for (int i = -nblocks; i; i++)
      {
          uint32_t k1 = getblock32(blocks,i);
  
          k1 *= c1;
          k1 = ROTL32(k1,15);
          k1 *= c2;
  
          h1 ^= k1;
          h1 = ROTL32(h1,13); 
          h1 = h1*5+0xe6546b64;
      }
  
      //----------
      // tail
  
      const int tail_len = len & 3;
      if (tail_len > 0) {
          murmurhash3::cp(ctx->tail, data + nblocks * 4, tail_len);
          ctx->tail_len = tail_len;
      }
  
      //----------
      // finalization
      ctx->h1 = h1;
      ctx->total_len += len;
  }
  
  void MurmurHash3_x86_32_Final(void * out, const MurmurHash3_x86_32_Context* ctx) {
      const uint32_t c1 = 0xcc9e2d51;
      const uint32_t c2 = 0x1b873593;
      uint32_t h1 = ctx->h1;
  
      uint32_t k1 = 0;
      const uint8_t* tail = ctx->tail; 
      switch (ctx->tail_len)
      {
      case 3: k1 ^= tail[2] << 16;
      case 2: k1 ^= tail[1] << 8;
      case 1: k1 ^= tail[0];
              k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
      };
  
      h1 ^= ctx->total_len;
      h1 = fmix32(h1);
      *(uint32_t*)out = h1;
  }
  
  } // namespace butil
  