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// Copyright 2017-2020 Peter Dimov.
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#define _CRT_SECURE_NO_WARNINGS
#include <boost/hash2/fnv1a.hpp>
#include <boost/hash2/siphash.hpp>
#include <boost/hash2/xxhash.hpp>
#include <boost/hash2/xxh3.hpp>
#include <boost/hash2/hash_append.hpp>
#include <boost/hash2/get_integral_result.hpp>
#include <boost/core/type_name.hpp>
#include <cstdint>
#include <chrono>
#include <random>
#include <typeinfo>
#include <cstddef>
#include <cstdio>
#include <string>
#include <vector>
#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
template<class T, class H> class hasher
{
private:
H h_;
private:
template<class = void> static void hash_append_impl( H& h, T const& v, std::false_type )
{
boost::hash2::hash_append( h, {}, v );
}
template<class = void> static void hash_append_impl( H& h, T const& v, std::true_type )
{
boost::hash2::hash_append_range( h, {}, v.data(), v.data() + v.size() );
}
public:
hasher(): h_()
{
}
explicit hasher( std::uint64_t seed ): h_( seed )
{
}
hasher( unsigned char const* seed, std::size_t n ): h_( seed, n )
{
}
std::size_t operator()( T const& v ) const
{
H h( h_ );
hash_append_impl( h, v, boost::container_hash::is_contiguous_range<T>() );
return boost::hash2::get_integral_result<std::size_t>( h );
}
};
template<class H, class V> void test3( int N, V const& v, std::size_t seed )
{
typedef std::chrono::steady_clock clock_type;
clock_type::time_point t1 = clock_type::now();
std::size_t q = 0;
hasher<std::string, H> const h( seed );
for( int i = 0; i < N; ++i )
{
q += h( v[i] );
}
clock_type::time_point t2 = clock_type::now();
long long ms1 = std::chrono::duration_cast<std::chrono::milliseconds>( t2 - t1 ).count();
std::string hash = boost::core::type_name<H>();
std::printf( "%s: q=%zu, %lld ms\n", hash.c_str(), q, ms1 );
}
template<class H, class V> void test2( int N, V const& v )
{
test3<H>( N, v, 0x9e3779b9 );
}
int main()
{
int const N = 16 * 1048576;
std::vector<std::string> v;
{
v.reserve( N );
std::mt19937_64 rnd;
for( int i = 0; i < N; ++i )
{
char buffer[ 64 ];
unsigned long long k = rnd();
if( k & 1 )
{
std::snprintf( buffer, sizeof( buffer ), "prefix_%llu_suffix", k );
}
else
{
std::snprintf( buffer, sizeof( buffer ), "{%u}", static_cast<unsigned>( k ) );
}
v.push_back( buffer );
}
}
using namespace boost::hash2;
test2<fnv1a_32>( N, v );
test2<fnv1a_64>( N, v );
test2<xxhash_32>( N, v );
test2<xxhash_64>( N, v );
test2<xxh3_128>( N, v );
test2<siphash_32>( N, v );
test2<siphash_64>( N, v );
std::puts( "" );
}
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