Make FlightCallOptions a POD type

cpp/src/arrow/flight/client.cc

@@ -51,24 +51,7 @@ class MemoryPool;
 
 namespace flight {
 
-class FlightCallOptions::Impl {
- private:
-  bool timeout_set_ = false;
-  TimeoutDuration timeout_;
-  friend class FlightCallOptions;
-};
-
-FlightCallOptions::FlightCallOptions() : impl_(new FlightCallOptions::Impl()) {}
-FlightCallOptions::~FlightCallOptions() = default;
-
-void FlightCallOptions::set_timeout(const TimeoutDuration& timeout_sec) {
-  impl_->timeout_set_ = true;
-  impl_->timeout_ = timeout_sec;
-}
-
-const TimeoutDuration& FlightCallOptions::timeout() const { return impl_->timeout_; }
-
-bool FlightCallOptions::HasTimeout() const { return impl_->timeout_set_; }
+FlightCallOptions::FlightCallOptions() : timeout(-1) {}
 
 struct ClientRpc {
   grpc::ClientContext context;
@@ -77,10 +60,10 @@ struct ClientRpc {
     /// XXX workaround until we have a handshake in Connect
     context.set_wait_for_ready(true);
 
-    if (options.HasTimeout()) {
+    if (options.timeout.count() >= 0) {
       std::chrono::system_clock::time_point deadline =
           std::chrono::time_point_cast<std::chrono::system_clock::time_point::duration>(
-              std::chrono::system_clock::now() + options.timeout());
+              std::chrono::system_clock::now() + options.timeout);
       context.set_deadline(deadline);
     }
   }

cpp/src/arrow/flight/client.h

@@ -48,21 +48,13 @@ typedef std::chrono::duration<double, std::chrono::seconds::period> TimeoutDurat
 /// \brief Hints to the underlying RPC layer for Arrow Flight calls.
 class ARROW_EXPORT FlightCallOptions {
  public:
+  /// Create a default set of call options.
   FlightCallOptions();
-  ~FlightCallOptions();
-  /// \brief Set a timeout on this call. If the call does not complete
-  /// within the specified period, the call will complete with a
-  /// non-OK status.
-  void set_timeout(const TimeoutDuration& timeout_sec);
-  /// \brief Get the timeout for this call. Only valid if HasTimeout()
-  /// is true.
-  const TimeoutDuration& timeout() const;
-  /// \brief Check if a timeout was set for this call.
-  bool HasTimeout() const;
 
- private:
-  class Impl;
-  std::unique_ptr<Impl> impl_;
+  /// \brief An optional timeout for this call. Negative durations
+  /// mean an implementation-defined default behavior will be used
+  /// instead. This is the default value.
+  TimeoutDuration timeout;
 };
 
 /// \brief Client class for Arrow Flight RPC services (gRPC-based).

cpp/src/arrow/flight/flight-test.cc

@@ -364,7 +364,7 @@ TEST_F(TestFlightClient, TimeoutFires) {
   std::unique_ptr<FlightClient> client;
   ASSERT_OK(FlightClient::Connect("localhost", 30001, &client));
   FlightCallOptions options;
-  options.set_timeout(TimeoutDuration{0.2});
+  options.timeout = TimeoutDuration{0.2};
   std::unique_ptr<FlightInfo> info;
   auto start = std::chrono::system_clock::now();
   Status status = client->GetFlightInfo(options, FlightDescriptor{}, &info);
@@ -376,7 +376,7 @@ TEST_F(TestFlightClient, TimeoutFires) {
 TEST_F(TestFlightClient, NoTimeout) {
   // Call should complete quickly, so timeout should not fire
   FlightCallOptions options;
-  options.set_timeout(TimeoutDuration{0.5});
+  options.timeout = TimeoutDuration{0.5};
   std::unique_ptr<FlightInfo> info;
   auto start = std::chrono::system_clock::now();
   auto descriptor = FlightDescriptor::Path({"examples", "ints"});

python/pyarrow/_flight.pyx

@@ -41,7 +41,7 @@ cdef class FlightCallOptions:
 
     def __init__(self, timeout=None):
         if timeout is not None:
-            self.options.set_timeout(CTimeoutDuration(timeout))
+            self.options.timeout = CTimeoutDuration(timeout)
 
     @staticmethod
     cdef CFlightCallOptions* unwrap(obj):

python/pyarrow/includes/libarrow_flight.pxd

@@ -146,7 +146,7 @@ cdef extern from "arrow/flight/api.h" namespace "arrow" nogil:
 
     cdef cppclass CFlightCallOptions" arrow::flight::FlightCallOptions":
         CFlightCallOptions()
-        void set_timeout(CTimeoutDuration duration)
+        CTimeoutDuration timeout
 
     cdef cppclass CFlightClient" arrow::flight::FlightClient":
         @staticmethod