Function TestSlowInputStream

cpp/src/arrow/io/memory_test.cc:404–433

template <typename SlowStreamType>
void TestSlowInputStream() {
  using clock = std::chrono::high_resolution_clock;

  std::shared_ptr<RandomAccessFile> stream = BufferReader::FromString("abcdefghijkl");
  const double latency = 0.6;
  auto slow = std::make_shared<SlowStreamType>(stream, latency);

  ASSERT_FALSE(slow->closed());
  auto t1 = clock::now();
  ASSERT_OK_AND_ASSIGN(auto buf, slow->Read(6));
  auto t2 = clock::now();
  AssertBufferEqual(*buf, "abcdef");
  auto dt = std::chrono::duration_cast<std::chrono::duration<double>>(t2 - t1).count();
#ifdef ARROW_WITH_TIMING_TESTS
  ASSERT_LT(dt, latency * 3);  // likely
  ASSERT_GT(dt, latency / 3);  // likely
#else
  ARROW_UNUSED(dt);
#endif

  ASSERT_OK_AND_ASSIGN(std::string_view view, slow->Peek(4));
  ASSERT_EQ(view, std::string_view("ghij"));

  ASSERT_OK(slow->Close());
  ASSERT_TRUE(slow->closed());
  ASSERT_TRUE(stream->closed());
  ASSERT_OK(slow->Close());
  ASSERT_TRUE(slow->closed());
  ASSERT_TRUE(stream->closed());
}

TEST(TestSlowInputStream, Basics) { TestSlowInputStream<SlowInputStream>(); }