// 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.

// This file is copied from

// https://github.com/apache/impala/blob/branch-2.9.0/be/src/util/hash-util.h

// and modified by Doris

#pragma once

#include <gen_cpp/Types_types.h>

#include <xxh3.h>

#include <zlib.h>

#include <functional>

#include "common/compiler_util.h" // IWYU pragma: keep

#include "gutil/hash/city.h"

#include "runtime/define_primitive_type.h"

#include "util/cpu_info.h"

#include "util/murmur_hash3.h"

#include "util/sse_util.hpp"

namespace doris {

// Utility class to compute hash values.

class HashUtil {

public:

    template <typename T>

    static uint32_t fixed_len_to_uint32(T value) {

        if constexpr (sizeof(T) <= sizeof(uint32_t)) {

            return (uint32_t)value;

        }

        return std::hash<T>()(value);

    }

    static uint32_t zlib_crc_hash(const void* data, int32_t bytes, uint32_t hash) {

        return crc32(hash, (const unsigned char*)data, bytes);

    }

    static uint32_t zlib_crc_hash_null(uint32_t hash) {

        // null is treat as 0 when hash

        static const int INT_VALUE = 0;

        return crc32(hash, (const unsigned char*)(&INT_VALUE), 4);

    }

#if defined(__SSE4_2__) || defined(__aarch64__)

    // Compute the Crc32 hash for data using SSE4 instructions.  The input hash parameter is

    // the current hash/seed value.

    // This should only be called if SSE is supported.

    // This is ~4x faster than Fnv/Boost Hash.

    // NOTE: DO NOT use this method for checksum! This does not generate the standard CRC32 checksum!

    //       For checksum, use CRC-32C algorithm from crc32c.h

    // NOTE: Any changes made to this function need to be reflected in Codegen::GetHashFn.

    // TODO: crc32 hashes with different seeds do not result in different hash functions.

    // The resulting hashes are correlated.

    static uint32_t crc_hash(const void* data, int32_t bytes, uint32_t hash) {

        if (!CpuInfo::is_supported(CpuInfo::SSE4_2)) {

            return zlib_crc_hash(data, bytes, hash);

        }

        uint32_t words = bytes / sizeof(uint32_t);

        bytes = bytes % sizeof(uint32_t);

        const uint32_t* p = reinterpret_cast<const uint32_t*>(data);

        while (words--) {

            hash = _mm_crc32_u32(hash, *p);

            ++p;

        }

        const uint8_t* s = reinterpret_cast<const uint8_t*>(p);

        while (bytes--) {

            hash = _mm_crc32_u8(hash, *s);

            ++s;

        }

        // The lower half of the CRC hash has has poor uniformity, so swap the halves

        // for anyone who only uses the first several bits of the hash.

        hash = (hash << 16) | (hash >> 16);

        return hash;

    }

    static uint64_t crc_hash64(const void* data, int32_t bytes, uint64_t hash) {

        uint32_t words = bytes / sizeof(uint32_t);

        bytes = bytes % sizeof(uint32_t);

        uint32_t h1 = hash >> 32;

        uint32_t h2 = (hash << 32) >> 32;

        const uint32_t* p = reinterpret_cast<const uint32_t*>(data);

        while (words--) {

            (words & 1) ? (h1 = _mm_crc32_u32(h1, *p)) : (h2 = _mm_crc32_u32(h2, *p));

            ++p;

        }

        const uint8_t* s = reinterpret_cast<const uint8_t*>(p);

        while (bytes--) {

            (bytes & 1) ? (h1 = _mm_crc32_u8(h1, *s)) : (h2 = _mm_crc32_u8(h2, *s));

            ++s;

        }

        union {

            uint64_t u64;

            uint32_t u32[2];

        } converter;

        converter.u64 = hash;

        h1 = (h1 << 16) | (h1 >> 16);

        h2 = (h2 << 16) | (h2 >> 16);

        converter.u32[0] = h1;

        converter.u32[1] = h2;

        return converter.u64;

    }

#else

    static uint32_t crc_hash(const void* data, int32_t bytes, uint32_t hash) {

        return zlib_crc_hash(data, bytes, hash);

    }

#endif

    // refer to https://github.com/apache/commons-codec/blob/master/src/main/java/org/apache/commons/codec/digest/MurmurHash3.java

    static const uint32_t MURMUR3_32_SEED = 104729;

    // modify from https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp

    static uint32_t murmur_hash3_32(const void* key, int64_t len, uint32_t seed) {

        uint32_t out = 0;

        murmur_hash3_x86_32(key, len, seed, &out);

        return out;

    }

    static const int MURMUR_R = 47;

    // Murmur2 hash implementation returning 64-bit hashes.

    static uint64_t murmur_hash2_64(const void* input, int len, uint64_t seed) {

        uint64_t h = seed ^ (len * MURMUR_PRIME);

        const uint64_t* data = reinterpret_cast<const uint64_t*>(input);

        const uint64_t* end = data + (len / sizeof(uint64_t));

        while (data != end) {

            uint64_t k = *data++;

            k *= MURMUR_PRIME;

            k ^= k >> MURMUR_R;

            k *= MURMUR_PRIME;

            h ^= k;

            h *= MURMUR_PRIME;

        }

        const uint8_t* data2 = reinterpret_cast<const uint8_t*>(data);

        switch (len & 7) {

        case 7:

            h ^= uint64_t(data2[6]) << 48;

            [[fallthrough]];

        case 6:

            h ^= uint64_t(data2[5]) << 40;

            [[fallthrough]];

        case 5:

            h ^= uint64_t(data2[4]) << 32;

            [[fallthrough]];

        case 4:

            h ^= uint64_t(data2[3]) << 24;

            [[fallthrough]];

        case 3:

            h ^= uint64_t(data2[2]) << 16;

            [[fallthrough]];

        case 2:

            h ^= uint64_t(data2[1]) << 8;

            [[fallthrough]];

        case 1:

            h ^= uint64_t(data2[0]);

            h *= MURMUR_PRIME;

        }

        h ^= h >> MURMUR_R;

        h *= MURMUR_PRIME;

        h ^= h >> MURMUR_R;

        return h;

    }

    // default values recommended by http://isthe.com/chongo/tech/comp/fnv/

    static const uint32_t FNV_PRIME = 0x01000193; //   16777619

    static const uint32_t FNV_SEED = 0x811C9DC5;  // 2166136261

    static const uint64_t FNV64_PRIME = 1099511628211UL;

    static const uint64_t FNV64_SEED = 14695981039346656037UL;

    static const uint64_t MURMUR_PRIME = 0xc6a4a7935bd1e995ULL;

    static const uint32_t MURMUR_SEED = 0xadc83b19ULL;

    // Implementation of the Fowler–Noll–Vo hash function.  This is not as performant

    // as boost's hash on int types (2x slower) but has bit entropy.

    // For ints, boost just returns the value of the int which can be pathological.

    // For example, if the data is <1000, 2000, 3000, 4000, ..> and then the mod of 1000

    // is taken on the hash, all values will collide to the same bucket.

    // For string values, Fnv is slightly faster than boost.

    static uint32_t fnv_hash(const void* data, int32_t bytes, uint32_t hash) {

        const uint8_t* ptr = reinterpret_cast<const uint8_t*>(data);

        while (bytes--) {

            hash = (*ptr ^ hash) * FNV_PRIME;

            ++ptr;

        }

        return hash;

    }

    static uint64_t fnv_hash64(const void* data, int32_t bytes, uint64_t hash) {

        const uint8_t* ptr = reinterpret_cast<const uint8_t*>(data);

        while (bytes--) {

            hash = (*ptr ^ hash) * FNV64_PRIME;

            ++ptr;

        }

        return hash;

    }

    // Our hash function is MurmurHash2, 64 bit version.

    // It was modified in order to provide the same result in

    // big and little endian archs (endian neutral).

    static uint64_t murmur_hash64A(const void* key, int64_t len, unsigned int seed) {

        const uint64_t m = MURMUR_PRIME;

        const int r = 47;

        uint64_t h = seed ^ (len * m);

        const uint8_t* data = (const uint8_t*)key;

        const uint8_t* end = data + (len - (len & 7));

        while (data != end) {

            uint64_t k;

#if (BYTE_ORDER == BIG_ENDIAN)

            k = (uint64_t)data[0];

            k |= (uint64_t)data[1] << 8;

            k |= (uint64_t)data[2] << 16;

            k |= (uint64_t)data[3] << 24;

            k |= (uint64_t)data[4] << 32;

            k |= (uint64_t)data[5] << 40;

            k |= (uint64_t)data[6] << 48;

            k |= (uint64_t)data[7] << 56;

#else

            k = *((uint64_t*)data);

#endif

            k *= m;

            k ^= k >> r;

            k *= m;

            h ^= k;

            h *= m;

            data += 8;

        }

        switch (len & 7) {

        case 7:

            h ^= (uint64_t)data[6] << 48;

            [[fallthrough]];

        case 6:

            h ^= (uint64_t)data[5] << 40;

            [[fallthrough]];

        case 5:

            h ^= (uint64_t)data[4] << 32;

            [[fallthrough]];

        case 4:

            h ^= (uint64_t)data[3] << 24;

            [[fallthrough]];

        case 3:

            h ^= (uint64_t)data[2] << 16;

            [[fallthrough]];

        case 2:

            h ^= (uint64_t)data[1] << 8;

            [[fallthrough]];

        case 1:

            h ^= (uint64_t)data[0];

            h *= m;

        }

        h ^= h >> r;

        h *= m;

        h ^= h >> r;

        return h;

    }

    // Computes the hash value for data.  Will call either CrcHash or FnvHash

    // depending on hardware capabilities.

    // Seed values for different steps of the query execution should use different seeds

    // to prevent accidental key collisions. (See IMPALA-219 for more details).

    static uint32_t hash(const void* data, int32_t bytes, uint32_t seed) {

#ifdef __SSE4_2__

        if (LIKELY(CpuInfo::is_supported(CpuInfo::SSE4_2))) {

            return crc_hash(data, bytes, seed);

        } else {

            return fnv_hash(data, bytes, seed);

        }

#else

        return fnv_hash(data, bytes, seed);

#endif

    }

    static uint64_t hash64(const void* data, int32_t bytes, uint64_t seed) {

#ifdef _SSE4_2_

        if (LIKELY(CpuInfo::is_supported(CpuInfo::SSE4_2))) {

            return crc_hash64(data, bytes, seed);

        } else {

            uint64_t hash = 0;

            murmur_hash3_x64_64(data, bytes, seed, &hash);

            return hash;

        }

#else

        uint64_t hash = 0;

        murmur_hash3_x64_64(data, bytes, seed, &hash);

        return hash;

#endif

    }

    // hash_combine is the same with boost hash_combine,

    // except replace boost::hash with std::hash

    template <class T>

    static inline void hash_combine(std::size_t& seed, const T& v) {

        std::hash<T> hasher;

        seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);

    }

#if defined(__clang__)

#pragma clang diagnostic push

#pragma clang diagnostic ignored "-Wused-but-marked-unused"

#endif

    // xxHash function for a byte array.  For convenience, a 64-bit seed is also

    // hashed into the result.  The mapping may change from time to time.

    static xxh_u32 xxHash32WithSeed(const char* s, size_t len, xxh_u32 seed) {

        return XXH32(s, len, seed);

    }

    // same to the up function, just for null value

    static xxh_u32 xxHash32NullWithSeed(xxh_u32 seed) {

        static const int INT_VALUE = 0;

        return XXH32(reinterpret_cast<const char*>(&INT_VALUE), sizeof(int), seed);

    }

    static xxh_u64 xxHash64WithSeed(const char* s, size_t len, xxh_u64 seed) {

        return XXH3_64bits_withSeed(s, len, seed);

    }

    // same to the up function, just for null value

    static xxh_u64 xxHash64NullWithSeed(xxh_u64 seed) {

        static const int INT_VALUE = 0;

        return XXH3_64bits_withSeed(reinterpret_cast<const char*>(&INT_VALUE), sizeof(int), seed);

    }

#if defined(__clang__)

#pragma clang diagnostic pop

#endif

};

} // namespace doris

template <>

struct std::hash<doris::TUniqueId> {

    std::size_t operator()(const doris::TUniqueId& id) const {

        std::size_t seed = 0;

        seed = doris::HashUtil::hash(&id.lo, sizeof(id.lo), seed);

        seed = doris::HashUtil::hash(&id.hi, sizeof(id.hi), seed);

        return seed;

    }

};

template <>

struct std::hash<doris::TNetworkAddress> {

    size_t operator()(const doris::TNetworkAddress& address) const {

        std::size_t seed = 0;

        seed = doris::HashUtil::hash(address.hostname.data(), address.hostname.size(), seed);

        seed = doris::HashUtil::hash(&address.port, 4, seed);

        return seed;

    }

};

template <>

struct std::hash<std::pair<doris::TUniqueId, int64_t>> {

    size_t operator()(const std::pair<doris::TUniqueId, int64_t>& pair) const {

        size_t seed = 0;

        seed = doris::HashUtil::hash(&pair.first.lo, sizeof(pair.first.lo), seed);

        seed = doris::HashUtil::hash(&pair.first.hi, sizeof(pair.first.hi), seed);

        seed = doris::HashUtil::hash(&pair.second, sizeof(pair.second), seed);

        return seed;

    }

};

template <class First, class Second>

struct std::hash<std::pair<First, Second>> {

    size_t operator()(const pair<First, Second>& p) const {

        size_t h1 = std::hash<First>()(p.first);

        size_t h2 = std::hash<Second>()(p.second);

        return util_hash::HashLen16(h1, h2);

    }

};