Repo created

generator/translators_pool.cpp

@@ -0,0 +1,81 @@
+#include "generator/translators_pool.hpp"
+
+#include <future>
+
+namespace generator
+{
+TranslatorsPool::TranslatorsPool(std::shared_ptr<TranslatorInterface> const & original, size_t threadCount)
+  : m_threadPool(threadCount)
+{
+  CHECK_GREATER_OR_EQUAL(threadCount, 1, ());
+
+  m_translators.Push(original);
+  for (size_t i = 1; i < threadCount; ++i)
+    m_translators.Push(original->Clone());
+}
+
+void TranslatorsPool::Emit(std::vector<OsmElement> && elements)
+{
+  std::shared_ptr<TranslatorInterface> translator;
+  m_translators.WaitAndPop(translator);
+  m_threadPool.SubmitWork([&, translator, elements = std::move(elements)]() mutable
+  {
+    for (auto const & element : elements)
+      translator->Emit(element);
+
+    m_translators.Push(translator);
+  });
+}
+
+bool TranslatorsPool::Finish()
+{
+  m_threadPool.WaitingStop();
+  using TranslatorPtr = std::shared_ptr<TranslatorInterface>;
+  threads::ThreadSafeQueue<std::future<TranslatorPtr>> queue;
+  while (!m_translators.Empty())
+  {
+    std::promise<TranslatorPtr> p;
+    std::shared_ptr<TranslatorInterface> translator;
+    m_translators.TryPop(translator);
+    p.set_value(translator);
+    queue.Push(p.get_future());
+  }
+
+  base::ComputationalThreadPool pool(queue.Size() / 2 + 1);
+  CHECK_GREATER_OR_EQUAL(queue.Size(), 1, ());
+  while (queue.Size() != 1)
+  {
+    std::future<TranslatorPtr> left;
+    std::future<TranslatorPtr> right;
+    queue.WaitAndPop(left);
+    queue.WaitAndPop(right);
+
+    struct State
+    {
+      std::future<TranslatorPtr> left;
+      std::future<TranslatorPtr> right;
+    };
+
+    // Should be copyable to workaround MSVC bug (https://developercommunity.visualstudio.com/t/108672)
+    auto state = std::make_shared<State>();
+    state->left = std::move(left);
+    state->right = std::move(right);
+
+    queue.Push(pool.Submit([state = std::move(state)]() mutable
+    {
+      auto leftTranslator = state->left.get();
+      auto rigthTranslator = state->right.get();
+      rigthTranslator->Finish();
+      leftTranslator->Finish();
+      leftTranslator->Merge(*rigthTranslator);
+      return leftTranslator;
+    }));
+  }
+
+  std::future<TranslatorPtr> translatorFuture;
+  queue.WaitAndPop(translatorFuture);
+  auto translator = translatorFuture.get();
+  translator->Finish();
+  return translator->Save();
+}
+}  // namespace generator