util/hash/farmhash.h - platform/external/libtextclassifier - Git at Google

 /*
  * Copyright (C) 2017 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.
  */

 #ifndef KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_
 #define KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_

 #include <assert.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>   // for memcpy and memset
 #include <utility>

 #ifndef NAMESPACE_FOR_HASH_FUNCTIONS
 #define NAMESPACE_FOR_HASH_FUNCTIONS tc2farmhash
 #endif

 namespace NAMESPACE_FOR_HASH_FUNCTIONS {

 #if defined(FARMHASH_UINT128_T_DEFINED)
 inline uint64_t Uint128Low64(const uint128_t x) {
   return static_cast<uint64_t>(x);
 }
 inline uint64_t Uint128High64(const uint128_t x) {
   return static_cast<uint64_t>(x >> 64);
 }
 inline uint128_t Uint128(uint64_t lo, uint64_t hi) {
   return lo + (((uint128_t)hi) << 64);
 }
 #else
 typedef std::pair<uint64_t, uint64_t> uint128_t;
 inline uint64_t Uint128Low64(const uint128_t x) { return x.first; }
 inline uint64_t Uint128High64(const uint128_t x) { return x.second; }
 inline uint128_t Uint128(uint64_t lo, uint64_t hi) { return uint128_t(lo, hi); }
 #endif


 // BASIC STRING HASHING

 // Hash function for a byte array.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 size_t Hash(const char* s, size_t len);

 // Hash function for a byte array.  Most useful in 32-bit binaries.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint32_t Hash32(const char* s, size_t len);

 // Hash function for a byte array.  For convenience, a 32-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint32_t Hash32WithSeed(const char* s, size_t len, uint32_t seed);

 // Hash 128 input bits down to 64 bits of output.
 // Hash function for a byte array.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint64_t Hash64(const char* s, size_t len);

 // Hash function for a byte array.  For convenience, a 64-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint64_t Hash64WithSeed(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.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint64_t Hash64WithSeeds(const char* s, size_t len,
                        uint64_t seed0, uint64_t seed1);

 // Hash function for a byte array.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint128_t Hash128(const char* s, size_t len);

 // Hash function for a byte array.  For convenience, a 128-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 uint128_t Hash128WithSeed(const char* s, size_t len, uint128_t seed);

 // BASIC NON-STRING HASHING

 // This is intended to be a reasonably good hash function.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 inline uint64_t Hash128to64(uint128_t 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;
 }

 // FINGERPRINTING (i.e., good, portable, forever-fixed hash functions)

 // Fingerprint function for a byte array.  Most useful in 32-bit binaries.
 uint32_t Fingerprint32(const char* s, size_t len);

 // Fingerprint function for a byte array.
 uint64_t Fingerprint64(const char* s, size_t len);

 // Fingerprint function for a byte array.
 uint128_t Fingerprint128(const char* s, size_t len);

 // This is intended to be a good fingerprinting primitive.
 // See below for more overloads.
 inline uint64_t Fingerprint(uint128_t 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 >> 44);
   b *= kMul;
   b ^= (b >> 41);
   b *= kMul;
   return b;
 }

 // This is intended to be a good fingerprinting primitive.
 inline uint64_t Fingerprint(uint64_t x) {
   // Murmur-inspired hashing.
   const uint64_t kMul = 0x9ddfea08eb382d69ULL;
   uint64_t b = x * kMul;
   b ^= (b >> 44);
   b *= kMul;
   b ^= (b >> 41);
   b *= kMul;
   return b;
 }

 #ifndef FARMHASH_NO_CXX_STRING

 // Convenience functions to hash or fingerprint C++ strings.
 // These require that Str::data() return a pointer to the first char
 // (as a const char*) and that Str::length() return the string's length;
 // they work with std::string, for example.

 // Hash function for a byte array.  Most useful in 32-bit binaries.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline size_t Hash(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Hash(s.data(), s.length());
 }

 // Hash function for a byte array.  Most useful in 32-bit binaries.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint32_t Hash32(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Hash32(s.data(), s.length());
 }

 // Hash function for a byte array.  For convenience, a 32-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint32_t Hash32WithSeed(const Str& s, uint32_t seed) {
   assert(sizeof(s[0]) == 1);
   return Hash32WithSeed(s.data(), s.length(), seed);
 }

 // Hash 128 input bits down to 64 bits of output.
 // Hash function for a byte array.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint64_t Hash64(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Hash64(s.data(), s.length());
 }

 // Hash function for a byte array.  For convenience, a 64-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint64_t Hash64WithSeed(const Str& s, uint64_t seed) {
   assert(sizeof(s[0]) == 1);
   return Hash64WithSeed(s.data(), s.length(), seed);
 }

 // Hash function for a byte array.  For convenience, two seeds are also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint64_t Hash64WithSeeds(const Str& s, uint64_t seed0, uint64_t seed1) {
   assert(sizeof(s[0]) == 1);
   return Hash64WithSeeds(s.data(), s.length(), seed0, seed1);
 }

 // Hash function for a byte array.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint128_t Hash128(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Hash128(s.data(), s.length());
 }

 // Hash function for a byte array.  For convenience, a 128-bit seed is also
 // hashed into the result.
 // May change from time to time, may differ on different platforms, may differ
 // depending on NDEBUG.
 template <typename Str>
 inline uint128_t Hash128WithSeed(const Str& s, uint128_t seed) {
   assert(sizeof(s[0]) == 1);
   return Hash128(s.data(), s.length(), seed);
 }

 // FINGERPRINTING (i.e., good, portable, forever-fixed hash functions)

 // Fingerprint function for a byte array.  Most useful in 32-bit binaries.
 template <typename Str>
 inline uint32_t Fingerprint32(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Fingerprint32(s.data(), s.length());
 }

 // Fingerprint 128 input bits down to 64 bits of output.
 // Fingerprint function for a byte array.
 template <typename Str>
 inline uint64_t Fingerprint64(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Fingerprint64(s.data(), s.length());
 }

 // Fingerprint function for a byte array.
 template <typename Str>
 inline uint128_t Fingerprint128(const Str& s) {
   assert(sizeof(s[0]) == 1);
   return Fingerprint128(s.data(), s.length());
 }

 #endif

 }  // namespace NAMESPACE_FOR_HASH_FUNCTIONS

 #endif  // KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_
	/*
	* Copyright (C) 2017 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.
	*/

	#ifndef KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_
	#define KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_

	#include <assert.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h> // for memcpy and memset
	#include <utility>

	#ifndef NAMESPACE_FOR_HASH_FUNCTIONS
	#define NAMESPACE_FOR_HASH_FUNCTIONS tc2farmhash
	#endif

	namespace NAMESPACE_FOR_HASH_FUNCTIONS {

	#if defined(FARMHASH_UINT128_T_DEFINED)
	inline uint64_t Uint128Low64(const uint128_t x) {
	return static_cast<uint64_t>(x);
	}
	inline uint64_t Uint128High64(const uint128_t x) {
	return static_cast<uint64_t>(x >> 64);
	}
	inline uint128_t Uint128(uint64_t lo, uint64_t hi) {
	return lo + (((uint128_t)hi) << 64);
	}
	#else
	typedef std::pair<uint64_t, uint64_t> uint128_t;
	inline uint64_t Uint128Low64(const uint128_t x) { return x.first; }
	inline uint64_t Uint128High64(const uint128_t x) { return x.second; }
	inline uint128_t Uint128(uint64_t lo, uint64_t hi) { return uint128_t(lo, hi); }
	#endif


	// BASIC STRING HASHING

	// Hash function for a byte array.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	size_t Hash(const char* s, size_t len);

	// Hash function for a byte array. Most useful in 32-bit binaries.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint32_t Hash32(const char* s, size_t len);

	// Hash function for a byte array. For convenience, a 32-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint32_t Hash32WithSeed(const char* s, size_t len, uint32_t seed);

	// Hash 128 input bits down to 64 bits of output.
	// Hash function for a byte array.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint64_t Hash64(const char* s, size_t len);

	// Hash function for a byte array. For convenience, a 64-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint64_t Hash64WithSeed(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.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint64_t Hash64WithSeeds(const char* s, size_t len,
	uint64_t seed0, uint64_t seed1);

	// Hash function for a byte array.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint128_t Hash128(const char* s, size_t len);

	// Hash function for a byte array. For convenience, a 128-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	uint128_t Hash128WithSeed(const char* s, size_t len, uint128_t seed);

	// BASIC NON-STRING HASHING

	// This is intended to be a reasonably good hash function.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	inline uint64_t Hash128to64(uint128_t 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;
	}

	// FINGERPRINTING (i.e., good, portable, forever-fixed hash functions)

	// Fingerprint function for a byte array. Most useful in 32-bit binaries.
	uint32_t Fingerprint32(const char* s, size_t len);

	// Fingerprint function for a byte array.
	uint64_t Fingerprint64(const char* s, size_t len);

	// Fingerprint function for a byte array.
	uint128_t Fingerprint128(const char* s, size_t len);

	// This is intended to be a good fingerprinting primitive.
	// See below for more overloads.
	inline uint64_t Fingerprint(uint128_t 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 >> 44);
	b *= kMul;
	b ^= (b >> 41);
	b *= kMul;
	return b;
	}

	// This is intended to be a good fingerprinting primitive.
	inline uint64_t Fingerprint(uint64_t x) {
	// Murmur-inspired hashing.
	const uint64_t kMul = 0x9ddfea08eb382d69ULL;
	uint64_t b = x * kMul;
	b ^= (b >> 44);
	b *= kMul;
	b ^= (b >> 41);
	b *= kMul;
	return b;
	}

	#ifndef FARMHASH_NO_CXX_STRING

	// Convenience functions to hash or fingerprint C++ strings.
	// These require that Str::data() return a pointer to the first char
	// (as a const char*) and that Str::length() return the string's length;
	// they work with std::string, for example.

	// Hash function for a byte array. Most useful in 32-bit binaries.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline size_t Hash(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Hash(s.data(), s.length());
	}

	// Hash function for a byte array. Most useful in 32-bit binaries.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint32_t Hash32(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Hash32(s.data(), s.length());
	}

	// Hash function for a byte array. For convenience, a 32-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint32_t Hash32WithSeed(const Str& s, uint32_t seed) {
	assert(sizeof(s[0]) == 1);
	return Hash32WithSeed(s.data(), s.length(), seed);
	}

	// Hash 128 input bits down to 64 bits of output.
	// Hash function for a byte array.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint64_t Hash64(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Hash64(s.data(), s.length());
	}

	// Hash function for a byte array. For convenience, a 64-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint64_t Hash64WithSeed(const Str& s, uint64_t seed) {
	assert(sizeof(s[0]) == 1);
	return Hash64WithSeed(s.data(), s.length(), seed);
	}

	// Hash function for a byte array. For convenience, two seeds are also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint64_t Hash64WithSeeds(const Str& s, uint64_t seed0, uint64_t seed1) {
	assert(sizeof(s[0]) == 1);
	return Hash64WithSeeds(s.data(), s.length(), seed0, seed1);
	}

	// Hash function for a byte array.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint128_t Hash128(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Hash128(s.data(), s.length());
	}

	// Hash function for a byte array. For convenience, a 128-bit seed is also
	// hashed into the result.
	// May change from time to time, may differ on different platforms, may differ
	// depending on NDEBUG.
	template <typename Str>
	inline uint128_t Hash128WithSeed(const Str& s, uint128_t seed) {
	assert(sizeof(s[0]) == 1);
	return Hash128(s.data(), s.length(), seed);
	}

	// FINGERPRINTING (i.e., good, portable, forever-fixed hash functions)

	// Fingerprint function for a byte array. Most useful in 32-bit binaries.
	template <typename Str>
	inline uint32_t Fingerprint32(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Fingerprint32(s.data(), s.length());
	}

	// Fingerprint 128 input bits down to 64 bits of output.
	// Fingerprint function for a byte array.
	template <typename Str>
	inline uint64_t Fingerprint64(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Fingerprint64(s.data(), s.length());
	}

	// Fingerprint function for a byte array.
	template <typename Str>
	inline uint128_t Fingerprint128(const Str& s) {
	assert(sizeof(s[0]) == 1);
	return Fingerprint128(s.data(), s.length());
	}

	#endif

	} // namespace NAMESPACE_FOR_HASH_FUNCTIONS

	#endif // KNOWLEDGE_CEREBRA_SENSE_TEXT_CLASSIFIER_LIB2_UTIL_HASH_FARMHASH_H_