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			412 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			412 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
// Copyright 2021 Peter Dimov.
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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#define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
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#include <boost/unordered_map.hpp>
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#include <boost/multi_index_container.hpp>
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#include <boost/multi_index/hashed_index.hpp>
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#include <boost/multi_index/member.hpp>
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#include <boost/core/detail/splitmix64.hpp>
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#include <boost/config.hpp>
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#ifdef HAVE_ABSEIL
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# include "absl/container/node_hash_map.h"
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# include "absl/container/flat_hash_map.h"
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#endif
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#include <unordered_map>
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#include <vector>
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#include <memory>
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#include <cstdint>
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#include <iostream>
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#include <iomanip>
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#include <chrono>
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using namespace std::chrono_literals;
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static void print_time( std::chrono::steady_clock::time_point & t1, char const* label, std::uint32_t s, std::size_t size )
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{
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    auto t2 = std::chrono::steady_clock::now();
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    std::cout << label << ": " << ( t2 - t1 ) / 1ms << " ms (s=" << s << ", size=" << size << ")\n";
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    t1 = t2;
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}
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constexpr unsigned N = 2'000'000;
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constexpr int K = 10;
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static std::vector<std::string> indices1, indices2;
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static std::string make_index( unsigned x )
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{
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    char buffer[ 64 ];
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    std::snprintf( buffer, sizeof(buffer), "pfx_%u_sfx", x );
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    return buffer;
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}
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static std::string make_random_index( unsigned x )
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{
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    char buffer[ 64 ];
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    std::snprintf( buffer, sizeof(buffer), "pfx_%0*d_%u_sfx", x % 8 + 1, 0, x );
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    return buffer;
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}
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static void init_indices()
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{
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    indices1.reserve( N*2+1 );
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    indices1.push_back( make_index( 0 ) );
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    for( unsigned i = 1; i <= N*2; ++i )
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    {
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        indices1.push_back( make_index( i ) );
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    }
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    indices2.reserve( N*2+1 );
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    indices2.push_back( make_index( 0 ) );
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    {
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        boost::detail::splitmix64 rng;
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        for( unsigned i = 1; i <= N*2; ++i )
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        {
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            indices2.push_back( make_random_index( static_cast<std::uint32_t>( rng() ) ) );
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        }
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    }
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}
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template<class Map> BOOST_NOINLINE void test_insert( Map& map, std::chrono::steady_clock::time_point & t1 )
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{
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    for( unsigned i = 1; i <= N; ++i )
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    {
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        map.insert( { indices1[ i ], i } );
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    }
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    print_time( t1, "Consecutive insert",  0, map.size() );
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    for( unsigned i = 1; i <= N; ++i )
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    {
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        map.insert( { indices2[ i ], i } );
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    }
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    print_time( t1, "Random insert",  0, map.size() );
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    std::cout << std::endl;
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}
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template<class Map> BOOST_NOINLINE void test_lookup( Map& map, std::chrono::steady_clock::time_point & t1 )
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{
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    std::uint32_t s;
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    s = 0;
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    for( int j = 0; j < K; ++j )
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    {
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        for( unsigned i = 1; i <= N * 2; ++i )
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        {
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            auto it = map.find( indices1[ i ] );
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            if( it != map.end() ) s += it->second;
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        }
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    }
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    print_time( t1, "Consecutive lookup",  s, map.size() );
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    s = 0;
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    for( int j = 0; j < K; ++j )
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    {
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        for( unsigned i = 1; i <= N * 2; ++i )
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        {
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            auto it = map.find( indices2[ i ] );
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            if( it != map.end() ) s += it->second;
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        }
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    }
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    print_time( t1, "Random lookup",  s, map.size() );
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    std::cout << std::endl;
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}
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template<class Map> BOOST_NOINLINE void test_iteration( Map& map, std::chrono::steady_clock::time_point & t1 )
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{
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    auto it = map.begin();
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    while( it != map.end() )
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    {
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        if( it->second & 1 )
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        {
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            map.erase( it++ );
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        }
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        else
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        {
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            ++it;
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        }
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    }
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    print_time( t1, "Iterate and erase odd elements",  0, map.size() );
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    std::cout << std::endl;
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}
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template<class Map> BOOST_NOINLINE void test_erase( Map& map, std::chrono::steady_clock::time_point & t1 )
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{
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    for( unsigned i = 1; i <= N; ++i )
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    {
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        map.erase( indices1[ i ] );
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    }
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    print_time( t1, "Consecutive erase",  0, map.size() );
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    {
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        boost::detail::splitmix64 rng;
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        for( unsigned i = 1; i <= N; ++i )
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        {
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            map.erase( indices2[ i ] );
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        }
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    }
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    print_time( t1, "Random erase",  0, map.size() );
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    std::cout << std::endl;
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}
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// counting allocator
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static std::size_t s_alloc_bytes = 0;
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static std::size_t s_alloc_count = 0;
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template<class T> struct allocator
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{
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    using value_type = T;
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    allocator() = default;
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    template<class U> allocator( allocator<U> const & ) noexcept
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    {
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    }
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    template<class U> bool operator==( allocator<U> const & ) const noexcept
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    {
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        return true;
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    }
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    template<class U> bool operator!=( allocator<U> const& ) const noexcept
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    {
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        return false;
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    }
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    T* allocate( std::size_t n ) const
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    {
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        s_alloc_bytes += n * sizeof(T);
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        s_alloc_count++;
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        return std::allocator<T>().allocate( n );
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    }
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    void deallocate( T* p, std::size_t n ) const noexcept
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    {
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        s_alloc_bytes -= n * sizeof(T);
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        s_alloc_count--;
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        std::allocator<T>().deallocate( p, n );
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    }
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};
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//
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struct record
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{
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    std::string label_;
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    long long time_;
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    std::size_t bytes_;
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    std::size_t count_;
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};
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static std::vector<record> times;
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template<template<class...> class Map> BOOST_NOINLINE void test( char const* label )
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{
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    std::cout << label << ":\n\n";
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    s_alloc_bytes = 0;
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    s_alloc_count = 0;
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    Map<std::string, std::uint32_t> map;
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    auto t0 = std::chrono::steady_clock::now();
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    auto t1 = t0;
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    test_insert( map, t1 );
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    std::cout << "Memory: " << s_alloc_bytes << " bytes in " << s_alloc_count << " allocations\n\n";
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    record rec = { label, 0, s_alloc_bytes, s_alloc_count };
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    test_lookup( map, t1 );
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    test_iteration( map, t1 );
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    test_lookup( map, t1 );
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    test_erase( map, t1 );
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    auto tN = std::chrono::steady_clock::now();
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    std::cout << "Total: " << ( tN - t0 ) / 1ms << " ms\n\n";
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    rec.time_ = ( tN - t0 ) / 1ms;
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    times.push_back( rec );
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}
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// multi_index emulation of unordered_map
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template<class K, class V> struct pair
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{
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    K first;
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    mutable V second;
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};
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using namespace boost::multi_index;
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template<class K, class V> using multi_index_map = multi_index_container<
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  pair<K, V>,
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  indexed_by<
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    hashed_unique< member<pair<K, V>, K, &pair<K, V>::first> >
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  >,
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  ::allocator< pair<K, V> >
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>;
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// aliases using the counting allocator
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template<class K, class V> using allocator_for = ::allocator< std::pair<K const, V> >;
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template<class K, class V> using std_unordered_map =
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    std::unordered_map<K, V, std::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
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template<class K, class V> using boost_unordered_map =
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    boost::unordered_map<K, V, boost::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
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#ifdef HAVE_ABSEIL
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template<class K, class V> using absl_node_hash_map =
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    absl::node_hash_map<K, V, absl::container_internal::hash_default_hash<K>, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
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template<class K, class V> using absl_flat_hash_map =
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    absl::flat_hash_map<K, V, absl::container_internal::hash_default_hash<K>, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
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#endif
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// fnv1a_hash
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template<int Bits> struct fnv1a_hash_impl;
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template<> struct fnv1a_hash_impl<32>
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{
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    std::size_t operator()( std::string const& s ) const
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    {
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        std::size_t h = 0x811C9DC5u;
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        char const * first = s.data();
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        char const * last = first + s.size();
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        for( ; first != last; ++first )
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        {
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            h ^= static_cast<unsigned char>( *first );
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            h *= 0x01000193ul;
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        }
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        return h;
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    }
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};
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template<> struct fnv1a_hash_impl<64>
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{
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    std::size_t operator()( std::string const& s ) const
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    {
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        std::size_t h = 0xCBF29CE484222325ull;
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        char const * first = s.data();
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        char const * last = first + s.size();
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        for( ; first != last; ++first )
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        {
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            h ^= static_cast<unsigned char>( *first );
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            h *= 0x00000100000001B3ull;
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        }
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        return h;
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    }
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};
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struct fnv1a_hash: fnv1a_hash_impl< std::numeric_limits<std::size_t>::digits > {};
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template<class K, class V> using std_unordered_map_fnv1a =
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std::unordered_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
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template<class K, class V> using boost_unordered_map_fnv1a =
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    boost::unordered_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
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template<class K, class V> using multi_index_map_fnv1a = multi_index_container<
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  pair<K, V>,
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  indexed_by<
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    hashed_unique< member<pair<K, V>, K, &pair<K, V>::first>, fnv1a_hash >
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  >,
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  ::allocator< pair<K, V> >
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>;
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#ifdef HAVE_ABSEIL
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template<class K, class V> using absl_node_hash_map_fnv1a =
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    absl::node_hash_map<K, V, fnv1a_hash, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
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template<class K, class V> using absl_flat_hash_map_fnv1a =
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    absl::flat_hash_map<K, V, fnv1a_hash, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
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#endif
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//
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int main()
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{
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    init_indices();
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#if 0
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    test<std_unordered_map>( "std::unordered_map" );
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    test<boost_unordered_map>( "boost::unordered_map" );
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    test<multi_index_map>( "multi_index_map" );
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#ifdef HAVE_ABSEIL
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    test<absl_node_hash_map>( "absl::node_hash_map" );
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    test<absl_flat_hash_map>( "absl::flat_hash_map" );
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#endif
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#endif
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    test<std_unordered_map_fnv1a>( "std::unordered_map, FNV-1a" );
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    test<boost_unordered_map_fnv1a>( "boost::unordered_map, FNV-1a" );
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    test<multi_index_map_fnv1a>( "multi_index_map, FNV-1a" );
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#ifdef HAVE_ABSEIL
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    test<absl_node_hash_map_fnv1a>( "absl::node_hash_map, FNV-1a" );
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    test<absl_flat_hash_map_fnv1a>( "absl::flat_hash_map, FNV-1a" );
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#endif
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    std::cout << "---\n\n";
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    for( auto const& x: times )
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    {
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        std::cout << std::setw( 30 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
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    }
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}
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#ifdef HAVE_ABSEIL
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# include "absl/container/internal/raw_hash_set.cc"
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# include "absl/hash/internal/hash.cc"
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# include "absl/hash/internal/low_level_hash.cc"
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# include "absl/hash/internal/city.cc"
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#endif
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