From ddcab1c171f43835c2c49e33ec2611c28817a263 Mon Sep 17 00:00:00 2001
From: Christian Mazakas <christian.mazakas@gmail.com>
Date: Tue, 4 Apr 2023 15:16:52 -0700
Subject: [PATCH] Add impl of try_emplace, try_emplace_or_[c]visit

---
 .../boost/unordered/concurrent_flat_map.hpp   |  60 +++
 test/Jamfile.v2                               |   7 +-
 test/cfoa/try_emplace_tests.cpp               | 402 ++++++++++++++++++
 3 files changed, 468 insertions(+), 1 deletion(-)
 create mode 100644 test/cfoa/try_emplace_tests.cpp

diff --git a/include/boost/unordered/concurrent_flat_map.hpp b/include/boost/unordered/concurrent_flat_map.hpp
index 1caf3a6c..bbab9d5c 100644
--- a/include/boost/unordered/concurrent_flat_map.hpp
+++ b/include/boost/unordered/concurrent_flat_map.hpp
@@ -270,6 +270,66 @@ namespace boost {
         this->insert_or_visit(ilist.begin(), ilist.end(), f);
       }
 
+      template <class... Args>
+      bool try_emplace(key_type const& k, Args&&... args)
+      {
+        return table_.try_emplace(k, std::forward<Args>(args)...);
+      }
+
+      template <class... Args> bool try_emplace(key_type&& k, Args&&... args)
+      {
+        return table_.try_emplace(std::move(k), std::forward<Args>(args)...);
+      }
+
+      template <class K, class... Args>
+      typename std::enable_if<
+        detail::are_transparent<K, hasher, key_equal>::value, bool>::type
+      try_emplace(K&& k, Args&&... args)
+      {
+        return table_.try_emplace(
+          std::forward<K>(k), std::forward<Args>(args)...);
+      }
+
+      template <class F, class... Args>
+      bool try_emplace_or_visit(key_type const& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_visit(k, f, std::forward<Args>(args)...);
+      }
+
+      template <class F, class... Args>
+      bool try_emplace_or_cvisit(key_type const& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_cvisit(k, f, std::forward<Args>(args)...);
+      }
+
+      template <class F, class... Args>
+      bool try_emplace_or_visit(key_type&& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_visit(
+          std::move(k), f, std::forward<Args>(args)...);
+      }
+
+      template <class F, class... Args>
+      bool try_emplace_or_cvisit(key_type&& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_cvisit(
+          std::move(k), f, std::forward<Args>(args)...);
+      }
+
+      template <class K, class F, class... Args>
+      bool try_emplace_or_visit(K&& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_visit(
+          std::forward<K>(k), f, std::forward<Args>(args)...);
+      }
+
+      template <class K, class F, class... Args>
+      bool try_emplace_or_cvisit(K&& k, F f, Args&&... args)
+      {
+        return table_.try_emplace_or_cvisit(
+          std::forward<K>(k), f, std::forward<Args>(args)...);
+      }
+
       size_type erase(key_type const& k) { return table_.erase(k); }
 
       template <class K>
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 160e32b2..83e60710 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -214,5 +214,10 @@ rule build_cfoa ( name )
 
 build_cfoa insert_tests ;
 build_cfoa erase_tests ;
+build_cfoa try_emplace_tests ;
 
-alias cfoa_tests : cfoa_insert_tests cfoa_erase_tests ;
+alias cfoa_tests :
+  cfoa_insert_tests
+  cfoa_erase_tests
+  cfoa_try_emplace_tests
+;
diff --git a/test/cfoa/try_emplace_tests.cpp b/test/cfoa/try_emplace_tests.cpp
new file mode 100644
index 00000000..1dd39657
--- /dev/null
+++ b/test/cfoa/try_emplace_tests.cpp
@@ -0,0 +1,402 @@
+// Copyright (C) 2023 Christian Mazakas
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "helpers.hpp"
+
+#include <boost/unordered/concurrent_flat_map.hpp>
+
+#include <boost/core/ignore_unused.hpp>
+
+namespace {
+  test::seed_t initialize_seed(511933564);
+
+  struct lvalue_try_emplacer_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      thread_runner(values, [&x, &num_inserts](boost::span<T> s) {
+        for (auto const& r : s) {
+          bool b = x.try_emplace(r.first, r.second.x_);
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, x.size());
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_assignment, 0u);
+      BOOST_TEST_EQ(raii::move_assignment, 0u);
+    }
+  } lvalue_try_emplacer;
+
+  struct norehash_lvalue_try_emplacer_type : public lvalue_try_emplacer_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      x.reserve(values.size());
+      lvalue_try_emplacer_type::operator()(values, x);
+      BOOST_TEST_EQ(raii::move_constructor, 0u);
+    }
+  } norehash_lvalue_try_emplacer;
+
+  struct rvalue_try_emplacer_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      BOOST_TEST_EQ(raii::copy_constructor, 0u);
+
+      std::atomic<std::uint64_t> num_inserts{0};
+      thread_runner(values, [&x, &num_inserts](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace(std::move(r.first), r.second.x_);
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+
+      if (std::is_same<T, typename X::value_type>::value) {
+        BOOST_TEST_EQ(raii::copy_constructor, x.size());
+      } else {
+        BOOST_TEST_EQ(raii::copy_constructor, 0u);
+        BOOST_TEST_GE(raii::move_constructor, x.size());
+      }
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_assignment, 0u);
+      BOOST_TEST_EQ(raii::move_assignment, 0u);
+    }
+  } rvalue_try_emplacer;
+
+  struct norehash_rvalue_try_emplacer_type : public rvalue_try_emplacer_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      x.reserve(values.size());
+
+      BOOST_TEST_EQ(raii::copy_constructor, 0u);
+      BOOST_TEST_EQ(raii::move_constructor, 0u);
+
+      rvalue_try_emplacer_type::operator()(values, x);
+
+      if (std::is_same<T, typename X::value_type>::value) {
+        BOOST_TEST_EQ(raii::copy_constructor, x.size());
+        BOOST_TEST_EQ(raii::move_constructor, 0);
+      } else {
+        BOOST_TEST_EQ(raii::copy_constructor, 0u);
+        BOOST_TEST_EQ(raii::move_constructor, x.size());
+      }
+    }
+  } norehash_rvalue_try_emplacer;
+
+  struct transp_try_emplace_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      using is_transparent =
+        typename boost::make_void<typename X::hasher::is_transparent,
+          typename X::key_equal::is_transparent>::type;
+
+      boost::ignore_unused<is_transparent>();
+
+      BOOST_TEST_EQ(raii::default_constructor, 0u);
+
+      std::atomic<std::uint64_t> num_inserts{0};
+
+      thread_runner(values, [&x, &num_inserts](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace(r.first.x_, r.second.x_);
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(raii::default_constructor, 2 * x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, 0u);
+      BOOST_TEST_EQ(raii::copy_assignment, 0u);
+      BOOST_TEST_EQ(raii::move_assignment, 0u);
+    }
+  } transp_try_emplace;
+
+  struct norehash_transp_try_emplace_type : public transp_try_emplace_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      x.reserve(values.size());
+      transp_try_emplace_type::operator()(values, x);
+      BOOST_TEST_EQ(raii::move_constructor, 0u);
+    }
+  } norehash_transp_try_emplace;
+
+  struct lvalue_try_emplace_or_cvisit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_cvisit(
+            r.first,
+            [&num_invokes](typename X::value_type const& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, x.size());
+      // don't check move construction count here because of rehashing
+      BOOST_TEST_GT(raii::move_constructor, 0u);
+      BOOST_TEST_EQ(raii::move_assignment, 0u);
+      BOOST_TEST_EQ(raii::copy_assignment, 0u);
+    }
+  } lvalue_try_emplace_or_cvisit;
+
+  struct lvalue_try_emplace_or_visit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_visit(
+            r.first,
+            [&num_invokes](typename X::value_type& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, x.size());
+      // don't check move construction count here because of rehashing
+      BOOST_TEST_GT(raii::move_constructor, 0u);
+      BOOST_TEST_EQ(raii::move_assignment, 0u);
+      BOOST_TEST_EQ(raii::copy_assignment, 0u);
+    }
+  } lvalue_try_emplace_or_visit;
+
+  struct rvalue_try_emplace_or_cvisit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_cvisit(
+            std::move(r.first),
+            [&num_invokes](typename X::value_type const& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+
+      if (std::is_same<T, typename X::value_type>::value) {
+        BOOST_TEST_EQ(raii::copy_constructor, x.size());
+        BOOST_TEST_GE(raii::move_constructor, x.size());
+      } else {
+        BOOST_TEST_EQ(raii::copy_constructor, 0u);
+        BOOST_TEST_GE(raii::move_constructor, x.size());
+      }
+    }
+  } rvalue_try_emplace_or_cvisit;
+
+  struct rvalue_try_emplace_or_visit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_visit(
+            std::move(r.first),
+            [&num_invokes](typename X::value_type& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      if (std::is_same<T, typename X::value_type>::value) {
+        BOOST_TEST_EQ(raii::copy_constructor, x.size());
+        BOOST_TEST_GE(raii::move_constructor, x.size());
+      } else {
+        BOOST_TEST_EQ(raii::copy_constructor, 0u);
+        BOOST_TEST_GE(raii::move_constructor, x.size());
+      }
+    }
+  } rvalue_try_emplace_or_visit;
+
+  struct transp_try_emplace_or_cvisit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_cvisit(
+            r.first.x_,
+            [&num_invokes](typename X::value_type const& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+      BOOST_TEST_EQ(raii::default_constructor, 2 * x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, 0u);
+    }
+  } transp_try_emplace_or_cvisit;
+
+  struct transp_try_emplace_or_visit_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      std::atomic<std::uint64_t> num_inserts{0};
+      std::atomic<std::uint64_t> num_invokes{0};
+      thread_runner(values, [&x, &num_inserts, &num_invokes](boost::span<T> s) {
+        for (auto& r : s) {
+          bool b = x.try_emplace_or_visit(
+            r.first.x_,
+            [&num_invokes](typename X::value_type& v) {
+              (void)v;
+              ++num_invokes;
+            },
+            r.second.x_);
+
+          if (b) {
+            ++num_inserts;
+          }
+        }
+      });
+
+      BOOST_TEST_EQ(num_inserts, x.size());
+      BOOST_TEST_EQ(num_invokes, values.size() - x.size());
+
+      BOOST_TEST_EQ(raii::default_constructor, 2 * x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, 0u);
+    }
+  } transp_try_emplace_or_visit;
+
+  template <class X, class G, class F>
+  void try_emplace(X*, G gen, F try_emplacer, test::random_generator rg)
+  {
+    auto values = make_random_values(1024 * 16, [&] { return gen(rg); });
+    auto reference_map =
+      boost::unordered_flat_map<raii, raii>(values.begin(), values.end());
+    raii::reset_counts();
+
+    {
+      X x;
+
+      try_emplacer(values, x);
+
+      BOOST_TEST_EQ(x.size(), reference_map.size());
+
+      using value_type = typename X::value_type;
+      BOOST_TEST_EQ(x.size(), x.visit_all([&](value_type const& kv) {
+        BOOST_TEST(reference_map.contains(kv.first));
+        if (rg == test::sequential) {
+          BOOST_TEST_EQ(kv.second, reference_map[kv.first]);
+        }
+      }));
+    }
+
+    BOOST_TEST_GE(raii::default_constructor, 0u);
+    BOOST_TEST_GE(raii::copy_constructor, 0u);
+    BOOST_TEST_GE(raii::move_constructor, 0u);
+    BOOST_TEST_GT(raii::destructor, 0u);
+
+    BOOST_TEST_EQ(raii::default_constructor + raii::copy_constructor +
+                    raii::move_constructor,
+      raii::destructor);
+  }
+
+  boost::unordered::concurrent_flat_map<raii, raii>* map;
+  boost::unordered::concurrent_flat_map<raii, raii, transp_hash,
+    transp_key_equal>* transp_map;
+
+} // namespace
+
+using test::default_generator;
+using test::limited_range;
+using test::sequential;
+
+// clang-format off
+UNORDERED_TEST(
+  try_emplace,
+  ((map))
+  ((value_type_generator)(init_type_generator))
+  ((lvalue_try_emplacer)(norehash_lvalue_try_emplacer)
+   (rvalue_try_emplacer)(norehash_rvalue_try_emplacer)
+   (lvalue_try_emplace_or_cvisit)(lvalue_try_emplace_or_visit)
+   (rvalue_try_emplace_or_cvisit)(rvalue_try_emplace_or_visit))
+  ((default_generator)(sequential)(limited_range)))
+
+UNORDERED_TEST(
+  try_emplace,
+  ((transp_map))
+  ((init_type_generator))
+  ((transp_try_emplace)(norehash_transp_try_emplace)
+   (transp_try_emplace_or_cvisit)(transp_try_emplace_or_visit))
+  ((default_generator)(sequential)(limited_range)))
+// clang-format on
+
+RUN_TESTS()