hashjoin_example.cc

#include <algorithm>
#include <boost/container/map.hpp>
#include <chrono>
#include <iostream>
#include <map>
#include <random>
#include <unordered_map>
#include <vector>

#include "parallel_hashmap/btree.h"
#include "parallel_hashmap/phmap.h"

#include "absl/container/btree_map.h"

struct keyRow {
  int a = 0;
  int b = 0;
};

int main() {

  std::random_device rnd_device;
  // Specify the engine and distribution.
  std::mt19937 mersenne_engine{rnd_device()}; // Generates random integers
  std::uniform_int_distribution<int> dist{1, 128};
  auto gen = [&dist, &mersenne_engine]() { return dist(mersenne_engine); };

  std::vector<int> ltab(100'000);
  generate(begin(ltab), end(ltab), gen);
  std::vector<int> rtab(1000'000);
  generate(begin(rtab), end(rtab), gen);

  // std::vector<int32_t> ltab = {1, 2, 3};
  // std::vector<int32_t> rtab = {2, 3, 3};

  // std::multimap<int32_t, keyRow> hashMap;
  boost::container::multimap<int32_t, keyRow> hashMap;
  // phmap::btree_multimap<int32_t, keyRow> hashMap;
  // absl::btree_multimap<int32_t, keyRow> hashMap;
  auto start = std::chrono::steady_clock::now();
  for (auto lkey : ltab) {
    hashMap.emplace(std::make_pair(lkey, keyRow()));
  }
  auto end = std::chrono::steady_clock::now();
  std::chrono::duration<double> elapsed_seconds = end - start;
  std::cout << "elapsed time: " << elapsed_seconds.count() << "s\n";

  for (auto rkey : rtab) {

    auto range = hashMap.equal_range(rkey);

    for (auto i = range.first; i != range.second; ++i) {
      // std::cout << "joined " << i->first << (i->second).a << std::endl;
    }
  }
}