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// Copyright 2021 Peter Dimov.
// Copyright 2023-2024 Joaquin M Lopez Munoz.
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
#include <boost/unordered_map.hpp>
#include <boost/unordered/unordered_node_map.hpp>
#include <boost/unordered/unordered_flat_map.hpp>
#include <boost/core/detail/splitmix64.hpp>
#include <boost/config.hpp>
#ifdef HAVE_ABSEIL
# include "absl/container/node_hash_map.h"
# include "absl/container/flat_hash_map.h"
#endif
#ifdef HAVE_ANKERL_UNORDERED_DENSE
# include "ankerl/unordered_dense.h"
#endif
#include <unordered_map>
#include <string_view>
#include <vector>
#include <memory>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <chrono>
#include <type_traits>
using namespace std::chrono_literals;
static void print_time( std::chrono::steady_clock::time_point & t1, char const* label, std::uint32_t s, std::size_t size )
{
auto t2 = std::chrono::steady_clock::now();
std::cout << label << ": " << ( t2 - t1 ) / 1ms << " ms (s=" << s << ", size=" << size << ")\n";
t1 = t2;
}
constexpr unsigned N = 2'000'000;
constexpr int K = 10;
static std::vector<std::string> indices1, indices2;
static std::string make_index( unsigned x )
{
char buffer[ 64 ];
std::snprintf( buffer, sizeof(buffer), "pfx_%u_sfx", x );
return buffer;
}
static std::string make_random_index( unsigned x )
{
char buffer[ 64 ];
std::snprintf( buffer, sizeof(buffer), "pfx_%0*d_%u_sfx", x % 8 + 1, 0, x );
return buffer;
}
static void init_indices()
{
indices1.reserve( N*2+1 );
indices1.push_back( make_index( 0 ) );
for( unsigned i = 1; i <= N*2; ++i )
{
indices1.push_back( make_index( i ) );
}
indices2.reserve( N*2+1 );
indices2.push_back( make_index( 0 ) );
{
boost::detail::splitmix64 rng;
for( unsigned i = 1; i <= N*2; ++i )
{
indices2.push_back( make_random_index( static_cast<std::uint32_t>( rng() ) ) );
}
}
}
template<class Map> BOOST_NOINLINE void test_insert( Map& map, std::chrono::steady_clock::time_point & t1 )
{
for( unsigned i = 1; i <= N; ++i )
{
map.insert( { indices1[ i ], i } );
}
print_time( t1, "Consecutive insert", 0, map.size() );
for( unsigned i = 1; i <= N; ++i )
{
map.insert( { indices2[ i ], i } );
}
print_time( t1, "Random insert", 0, map.size() );
std::cout << std::endl;
}
template<class Map> BOOST_NOINLINE void test_lookup( Map& map, std::chrono::steady_clock::time_point & t1 )
{
std::uint32_t s;
s = 0;
for( int j = 0; j < K; ++j )
{
for( unsigned i = 1; i <= N * 2; ++i )
{
auto it = map.find( indices1[ i ] );
if( it != map.end() ) s += it->second;
}
}
print_time( t1, "Consecutive lookup", s, map.size() );
s = 0;
for( int j = 0; j < K; ++j )
{
for( unsigned i = 1; i <= N * 2; ++i )
{
auto it = map.find( indices2[ i ] );
if( it != map.end() ) s += it->second;
}
}
print_time( t1, "Random lookup", s, map.size() );
std::cout << std::endl;
}
template<class Map> BOOST_NOINLINE void test_iteration( Map& map, std::chrono::steady_clock::time_point & t1 )
{
auto it = map.begin();
while( it != map.end() )
{
if( it->second & 1 )
{
if constexpr( std::is_void_v< decltype( map.erase( it ) ) > )
{
map.erase( it++ );
}
else
{
it = map.erase( it );
}
}
else
{
++it;
}
}
print_time( t1, "Iterate and erase odd elements", 0, map.size() );
std::cout << std::endl;
}
template<class Map> BOOST_NOINLINE void test_erase( Map& map, std::chrono::steady_clock::time_point & t1 )
{
for( unsigned i = 1; i <= N; ++i )
{
map.erase( indices1[ i ] );
}
print_time( t1, "Consecutive erase", 0, map.size() );
for( unsigned i = 1; i <= N; ++i )
{
map.erase( indices2[ i ] );
}
print_time( t1, "Random erase", 0, map.size() );
std::cout << std::endl;
}
// counting allocator
static std::size_t s_alloc_bytes = 0;
static std::size_t s_alloc_count = 0;
template<class T> struct allocator
{
using value_type = T;
allocator() = default;
template<class U> allocator( allocator<U> const & ) noexcept
{
}
template<class U> bool operator==( allocator<U> const & ) const noexcept
{
return true;
}
template<class U> bool operator!=( allocator<U> const& ) const noexcept
{
return false;
}
T* allocate( std::size_t n ) const
{
s_alloc_bytes += n * sizeof(T);
s_alloc_count++;
return std::allocator<T>().allocate( n );
}
void deallocate( T* p, std::size_t n ) const noexcept
{
s_alloc_bytes -= n * sizeof(T);
s_alloc_count--;
std::allocator<T>().deallocate( p, n );
}
};
//
struct record
{
std::string label_;
long long time_;
std::size_t bytes_;
std::size_t count_;
};
static std::vector<record> times;
template<template<class...> class Map> BOOST_NOINLINE void test( char const* label )
{
std::cout << label << ":\n\n";
s_alloc_bytes = 0;
s_alloc_count = 0;
Map<std::string_view, std::uint32_t> map;
auto t0 = std::chrono::steady_clock::now();
auto t1 = t0;
test_insert( map, t1 );
std::cout << "Memory: " << s_alloc_bytes << " bytes in " << s_alloc_count << " allocations\n\n";
record rec = { label, 0, s_alloc_bytes, s_alloc_count };
test_lookup( map, t1 );
test_iteration( map, t1 );
test_lookup( map, t1 );
test_erase( map, t1 );
auto tN = std::chrono::steady_clock::now();
std::cout << "Total: " << ( tN - t0 ) / 1ms << " ms\n\n";
rec.time_ = ( tN - t0 ) / 1ms;
times.push_back( rec );
}
// aliases using the counting allocator
template<class K, class V> using allocator_for = ::allocator< std::pair<K const, V> >;
template<class K, class V> using std_unordered_map =
std::unordered_map<K, V, std::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_map =
boost::unordered_map<K, V, boost::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_node_map =
boost::unordered_node_map<K, V, boost::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_flat_map =
boost::unordered_flat_map<K, V, boost::hash<K>, std::equal_to<K>, allocator_for<K, V>>;
#ifdef HAVE_ABSEIL
template<class K, class V> using absl_node_hash_map =
absl::node_hash_map<K, V, absl::container_internal::hash_default_hash<K>, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
template<class K, class V> using absl_flat_hash_map =
absl::flat_hash_map<K, V, absl::container_internal::hash_default_hash<K>, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
#endif
#ifdef HAVE_ANKERL_UNORDERED_DENSE
template<class K, class V> using ankerl_unordered_dense_map =
ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
#endif
// fnv1a_hash
template<int Bits> struct fnv1a_hash_impl;
template<> struct fnv1a_hash_impl<32>
{
std::size_t operator()( std::string_view const& s ) const
{
std::size_t h = 0x811C9DC5u;
char const * first = s.data();
char const * last = first + s.size();
for( ; first != last; ++first )
{
h ^= static_cast<unsigned char>( *first );
h *= 0x01000193ul;
}
return h;
}
};
template<> struct fnv1a_hash_impl<64>
{
std::size_t operator()( std::string_view const& s ) const
{
std::size_t h = 0xCBF29CE484222325ull;
char const * first = s.data();
char const * last = first + s.size();
for( ; first != last; ++first )
{
h ^= static_cast<unsigned char>( *first );
h *= 0x00000100000001B3ull;
}
return h;
}
};
struct fnv1a_hash: fnv1a_hash_impl< std::numeric_limits<std::size_t>::digits >
{
using is_avalanching = std::true_type;
};
template<class K, class V> using std_unordered_map_fnv1a =
std::unordered_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_map_fnv1a =
boost::unordered_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_node_map_fnv1a =
boost::unordered_node_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
template<class K, class V> using boost_unordered_flat_map_fnv1a =
boost::unordered_flat_map<K, V, fnv1a_hash, std::equal_to<K>, allocator_for<K, V>>;
#ifdef HAVE_ABSEIL
template<class K, class V> using absl_node_hash_map_fnv1a =
absl::node_hash_map<K, V, fnv1a_hash, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
template<class K, class V> using absl_flat_hash_map_fnv1a =
absl::flat_hash_map<K, V, fnv1a_hash, absl::container_internal::hash_default_eq<K>, allocator_for<K, V>>;
#endif
#ifdef HAVE_ANKERL_UNORDERED_DENSE
template<class K, class V> using ankerl_unordered_dense_map_fnv1a =
ankerl::unordered_dense::map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
#endif
//
int main()
{
init_indices();
test<std_unordered_map>( "std::unordered_map" );
test<boost_unordered_map>( "boost::unordered_map" );
test<boost_unordered_node_map>( "boost::unordered_node_map" );
test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
#ifdef HAVE_ANKERL_UNORDERED_DENSE
test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
#endif
#ifdef HAVE_ABSEIL
test<absl_node_hash_map>( "absl::node_hash_map" );
test<absl_flat_hash_map>( "absl::flat_hash_map" );
#endif
test<std_unordered_map_fnv1a>( "std::unordered_map, FNV-1a" );
test<boost_unordered_map_fnv1a>( "boost::unordered_map, FNV-1a" );
test<boost_unordered_node_map_fnv1a>( "boost::unordered_node_map, FNV-1a" );
test<boost_unordered_flat_map_fnv1a>( "boost::unordered_flat_map, FNV-1a" );
#ifdef HAVE_ANKERL_UNORDERED_DENSE
test<ankerl_unordered_dense_map_fnv1a>( "ankerl::unordered_dense::map, FNV-1a" );
#endif
#ifdef HAVE_ABSEIL
test<absl_node_hash_map_fnv1a>( "absl::node_hash_map, FNV-1a" );
test<absl_flat_hash_map_fnv1a>( "absl::flat_hash_map, FNV-1a" );
#endif
std::cout << "---\n\n";
for( auto const& x: times )
{
std::cout << std::setw( 38 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
}
}
#ifdef HAVE_ABSEIL
# include "absl/container/internal/raw_hash_set.cc"
# include "absl/hash/internal/hash.cc"
# include "absl/hash/internal/low_level_hash.cc"
# include "absl/hash/internal/city.cc"
#endif