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-// Copyright 2018 The Abseil Authors.
-//
-// 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
-//
-//      https://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.
-//
-// https://code.google.com/p/cityhash/
-//
-// This file provides a few functions for hashing strings.  All of them are
-// high-quality functions in the sense that they pass standard tests such
-// as Austin Appleby's SMHasher.  They are also fast.
-//
-// For 64-bit x86 code, on short strings, we don't know of anything faster than
-// CityHash64 that is of comparable quality.  We believe our nearest competitor
-// is Murmur3.  For 64-bit x86 code, CityHash64 is an excellent choice for hash
-// tables and most other hashing (excluding cryptography).
-//
-// For 32-bit x86 code, we don't know of anything faster than CityHash32 that
-// is of comparable quality.  We believe our nearest competitor is Murmur3A.
-// (On 64-bit CPUs, it is typically faster to use the other CityHash variants.)
-//
-// Functions in the CityHash family are not suitable for cryptography.
-//
-// Please see CityHash's README file for more details on our performance
-// measurements and so on.
-//
-// WARNING: This code has been only lightly tested on big-endian platforms!
-// It is known to work well on little-endian platforms that have a small penalty
-// for unaligned reads, such as current Intel and AMD moderate-to-high-end CPUs.
-// It should work on all 32-bit and 64-bit platforms that allow unaligned reads;
-// bug reports are welcome.
-//
-// By the way, for some hash functions, given strings a and b, the hash
-// of a+b is easily derived from the hashes of a and b.  This property
-// doesn't hold for any hash functions in this file.
-
-#ifndef ABSL_HASH_INTERNAL_CITY_H_
-#define ABSL_HASH_INTERNAL_CITY_H_
-
-#include <stdint.h>
-#include <stdlib.h>  // for size_t.
-
-#include <utility>
-
-#include "absl/base/config.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace hash_internal {
-
-typedef std::pair<uint64_t, uint64_t> uint128;
-
-inline uint64_t Uint128Low64(const uint128 &x) { return x.first; }
-inline uint64_t Uint128High64(const uint128 &x) { return x.second; }
-
-// Hash function for a byte array.
-uint64_t CityHash64(const char *s, size_t len);
-
-// Hash function for a byte array.  For convenience, a 64-bit seed is also
-// hashed into the result.
-uint64_t CityHash64WithSeed(const char *s, size_t len, uint64_t seed);
-
-// Hash function for a byte array.  For convenience, two seeds are also
-// hashed into the result.
-uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0,
-                           uint64_t seed1);
-
-// Hash function for a byte array.  Most useful in 32-bit binaries.
-uint32_t CityHash32(const char *s, size_t len);
-
-// Hash 128 input bits down to 64 bits of output.
-// This is intended to be a reasonably good hash function.
-inline uint64_t Hash128to64(const uint128 &x) {
-  // Murmur-inspired hashing.
-  const uint64_t kMul = 0x9ddfea08eb382d69ULL;
-  uint64_t a = (Uint128Low64(x) ^ Uint128High64(x)) * kMul;
-  a ^= (a >> 47);
-  uint64_t b = (Uint128High64(x) ^ a) * kMul;
-  b ^= (b >> 47);
-  b *= kMul;
-  return b;
-}
-
-}  // namespace hash_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_HASH_INTERNAL_CITY_H_