add timestamp operator

6 files changed, 385 insertions, 0 deletions

diff --git a/Rx/v2/examples/doxygen/timestamp.cpp b/Rx/v2/examples/doxygen/timestamp.cpp
new file mode 100644
index 0000000..f17e5c0
--- /dev/null
+++ b/Rx/v2/examples/doxygen/timestamp.cpp
@@ -0,0 +1,51 @@
+#include "rxcpp/rx.hpp"
+
+#include "rxcpp/rx-test.hpp"
+#include "catch.hpp"
+
+SCENARIO("timestamp sample") {
+    printf("//! [timestamp sample]\n");
+
+    using namespace std::chrono;
+    auto values = rxcpp::observable<>::interval(milliseconds(100))
+            .timestamp()
+            .take(3);
+    values.
+        subscribe(
+            [](std::pair<long, typename rxsc::scheduler::clock_type::time_point> v) { printf("OnNext: %ld %lld\n", v.first, static_cast<long long>(v.second.time_since_epoch().count())); },
+            [](std::exception_ptr ep) {
+                try {
+                    std::rethrow_exception(ep);
+                } catch (const std::exception& ex) {
+                    printf("OnError: %s\n", ex.what());
+                }
+            },
+            []() { printf("OnCompleted\n"); });
+    printf("//! [timestamp sample]\n");
+}
+
+SCENARIO("timestamp operator syntax sample") {
+    using namespace rxcpp;
+    using namespace rxcpp::sources;
+    using namespace rxcpp::operators;
+    using namespace std::chrono;
+
+    typedef typename rxcpp::schedulers::scheduler::clock_type::time_point time_point;
+
+    printf("//! [timestamp operator syntax sample]\n");
+    auto values = interval(milliseconds(100))
+                  | timestamp()
+                  | take(3);
+    values.
+            subscribe(
+            [](std::pair<long, time_point> v) { printf("OnNext: %ld %lld\n", v.first, static_cast<long long>(v.second.time_since_epoch().count())); },
+            [](std::exception_ptr ep) {
+                try {
+                    std::rethrow_exception(ep);
+                } catch (const std::exception& ex) {
+                    printf("OnError: %s\n", ex.what());
+                }
+            },
+            []() { printf("OnCompleted\n"); });
+    printf("//! [timestamp operator syntax sample]\n");
+}
\ No newline at end of file
diff --git a/Rx/v2/src/rxcpp/operators/rx-timestamp.hpp b/Rx/v2/src/rxcpp/operators/rx-timestamp.hpp
new file mode 100644
index 0000000..17aff82
--- /dev/null
+++ b/Rx/v2/src/rxcpp/operators/rx-timestamp.hpp
@@ -0,0 +1,112 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#pragma once
+
+#if !defined(RXCPP_OPERATORS_RX_TIMESTAMP_HPP)
+#define RXCPP_OPERATORS_RX_TIMESTAMP_HPP
+
+#include "../rx-includes.hpp"
+
+namespace rxcpp {
+
+namespace operators {
+
+namespace detail {
+
+template<class T, class Coordination>
+struct timestamp
+{
+    static_assert(is_coordination<Coordination>::value, "Coordination parameter must satisfy the requirements for a Coordination");
+
+    typedef rxu::decay_t<T> source_value_type;
+    typedef rxu::decay_t<Coordination> coordination_type;
+
+    struct timestamp_values {
+        timestamp_values(coordination_type c)
+            : coordination(c)
+        {
+        }
+
+        coordination_type coordination;
+    };
+    timestamp_values initial;
+
+    timestamp(coordination_type coordination)
+        : initial(coordination)
+    {
+    }
+
+    template<class Subscriber>
+    struct timestamp_observer
+    {
+        typedef timestamp_observer<Subscriber> this_type;
+        typedef source_value_type value_type;
+        typedef rxu::decay_t<Subscriber> dest_type;
+        typedef observer<value_type, this_type> observer_type;
+        dest_type dest;
+        coordination_type coord;
+
+        timestamp_observer(dest_type d, coordination_type coordination)
+            : dest(std::move(d)),
+              coord(std::move(coordination))
+        {
+        }
+
+        void on_next(source_value_type v) const {
+            dest.on_next(std::make_pair(v, coord.now()));
+        }
+        void on_error(std::exception_ptr e) const {
+            dest.on_error(e);
+        }
+        void on_completed() const {
+            dest.on_completed();
+        }
+
+        static subscriber<value_type, observer<value_type, this_type>> make(dest_type d, timestamp_values v) {
+            return make_subscriber<value_type>(d, this_type(d, v.coordination));
+        }
+    };
+
+    template<class Subscriber>
+    auto operator()(Subscriber dest) const
+        -> decltype(timestamp_observer<Subscriber>::make(std::move(dest), initial)) {
+        return      timestamp_observer<Subscriber>::make(std::move(dest), initial);
+    }
+};
+
+template <class Coordination>
+class timestamp_factory
+{
+    typedef rxu::decay_t<Coordination> coordination_type;
+
+    coordination_type coordination;
+public:
+    timestamp_factory(coordination_type ct)
+        : coordination(std::move(ct)) { }
+
+    template<class Observable>
+    auto operator()(Observable&& source)
+        -> decltype(source.template lift<std::pair<rxu::value_type_t<rxu::decay_t<Observable>>, typename rxsc::scheduler::clock_type::time_point>>(timestamp<rxu::value_type_t<rxu::decay_t<Observable>>, Coordination>(coordination))) {
+        return      source.template lift<std::pair<rxu::value_type_t<rxu::decay_t<Observable>>, typename rxsc::scheduler::clock_type::time_point>>(timestamp<rxu::value_type_t<rxu::decay_t<Observable>>, Coordination>(coordination));
+    }
+
+};
+
+}
+
+template <class Coordination>
+inline auto timestamp(Coordination ct)
+->      detail::timestamp_factory<Coordination> {
+    return  detail::timestamp_factory<Coordination>(std::move(ct));
+}
+
+inline auto timestamp()
+->      detail::timestamp_factory<identity_one_worker> {
+    return  detail::timestamp_factory<identity_one_worker>(identity_current_thread());
+}
+
+}
+
+}
+
+#endif
diff --git a/Rx/v2/src/rxcpp/rx-observable.hpp b/Rx/v2/src/rxcpp/rx-observable.hpp
index cdeb1e0..678db71 100644
--- a/Rx/v2/src/rxcpp/rx-observable.hpp
+++ b/Rx/v2/src/rxcpp/rx-observable.hpp
@@ -878,6 +878,45 @@ public:
         return                    lift<T>(rxo::detail::timeout<T, Duration, identity_one_worker>(period, identity_current_thread()));
     }
 
+    /*! Returns an observable that attaches a timestamp to each item emitted by the source observable indicating when it was emitted.
+
+        \tparam Coordination  the type of the scheduler
+
+        \param coordination  the scheduler to manage timeout for each event
+
+        \return  Observable that emits a pair: { item emitted by the source observable, time_point representing the current value of the clock }.
+
+        \sample
+        \snippet timestamp.cpp timestamp sample
+        \snippet output.txt timestamp sample
+    */
+    template<class Coordination>
+    auto timestamp(Coordination coordination) const
+    /// \cond SHOW_SERVICE_MEMBERS
+    -> decltype(EXPLICIT_THIS lift<std::pair<T, rxsc::scheduler::clock_type::time_point>>(rxo::detail::timestamp<T, Coordination>{coordination}))
+    /// \endcond
+    {
+        return                lift<std::pair<T, rxsc::scheduler::clock_type::time_point>>(rxo::detail::timestamp<T, Coordination>{coordination});
+    }
+
+    /*! Returns an observable that attaches a timestamp to each item emitted by the source observable indicating when it was emitted.
+
+        \tparam ClockType    the type of the clock to return a time_point.
+
+        \return  Observable that emits a pair: { item emitted by the source observable, time_point representing the current value of the clock }.
+
+        \sample
+        \snippet timestamp.cpp timestamp sample
+        \snippet output.txt timestamp sample
+    */
+    auto timestamp() const
+    /// \cond SHOW_SERVICE_MEMBERS
+    -> decltype(EXPLICIT_THIS lift<std::pair<T, rxsc::scheduler::clock_type::time_point>>(rxo::detail::timestamp<T, identity_one_worker>{identity_current_thread()}))
+    /// \endcond
+    {
+        return                lift<std::pair<T, rxsc::scheduler::clock_type::time_point>>(rxo::detail::timestamp<T, identity_one_worker>{identity_current_thread()});
+    }
+
     /*! Add a new action at the end of the new observable that is returned.
 
         \tparam LastCall  the type of the action function
diff --git a/Rx/v2/src/rxcpp/rx-operators.hpp b/Rx/v2/src/rxcpp/rx-operators.hpp
index aebd930..f23d710 100644
--- a/Rx/v2/src/rxcpp/rx-operators.hpp
+++ b/Rx/v2/src/rxcpp/rx-operators.hpp
@@ -79,6 +79,7 @@ namespace rxo=operators;
 #include "operators/rx-take_until.hpp"
 #include "operators/rx-tap.hpp"
 #include "operators/rx-timeout.hpp"
+#include "operators/rx-timestamp.hpp"
 #include "operators/rx-with_latest_from.hpp"
 #include "operators/rx-window.hpp"
 #include "operators/rx-window_time.hpp"
diff --git a/Rx/v2/test/CMakeLists.txt b/Rx/v2/test/CMakeLists.txt
index b900031..ee3f01a 100644
--- a/Rx/v2/test/CMakeLists.txt
+++ b/Rx/v2/test/CMakeLists.txt
@@ -66,6 +66,7 @@ set(TEST_SOURCES
     ${TEST_DIR}/operators/take_until.cpp
     ${TEST_DIR}/operators/tap.cpp
     ${TEST_DIR}/operators/timeout.cpp
+    ${TEST_DIR}/operators/timestamp.cpp
     ${TEST_DIR}/operators/with_latest_from.cpp
     ${TEST_DIR}/operators/window.cpp
     ${TEST_DIR}/operators/zip.cpp
diff --git a/Rx/v2/test/operators/timestamp.cpp b/Rx/v2/test/operators/timestamp.cpp
new file mode 100644
index 0000000..f6ea82b
--- /dev/null
+++ b/Rx/v2/test/operators/timestamp.cpp
@@ -0,0 +1,181 @@
+#include "../test.h"
+
+using namespace std::chrono;
+
+SCENARIO("should not emit timestamped items if the source never emits any items", "[timestamp][operators]"){
+    GIVEN("a source"){
+        typedef typename rxsc::detail::test_type::clock_type::time_point time_point;
+
+        auto sc = rxsc::make_test();
+        auto w = sc.create_worker();
+        const rxsc::test::messages<int> on;
+
+        auto xs = sc.make_hot_observable({
+            on.next(150, 1)
+        });
+
+        WHEN("timestamp operator is invoked"){
+
+            auto res = w.start(
+                [xs]() {
+                    return xs.timestamp();
+                }
+            );
+
+            THEN("the output is empty"){
+                auto required = std::vector<rxsc::test::messages<std::pair<int, time_point>>::recorded_type>();
+                auto actual = res.get_observer().messages();
+                REQUIRE(required == actual);
+            }
+
+            THEN("there was 1 subscription/unsubscription to the source"){
+                auto required = rxu::to_vector({
+                    on.subscribe(200, 1000)
+                });
+                auto actual = xs.subscriptions();
+                REQUIRE(required == actual);
+            }
+        }
+    }
+}
+
+SCENARIO("should not emit timestamped items if the source observable is empty", "[timestamp][operators]"){
+    GIVEN("a source"){
+        typedef typename rxsc::detail::test_type::clock_type::time_point time_point;
+
+        auto sc = rxsc::make_test();
+        auto so = rx::synchronize_in_one_worker(sc);
+        auto w = sc.create_worker();
+        const rxsc::test::messages<int> on;
+        const rxsc::test::messages<std::pair<int, time_point>> on_timestamp;
+
+        auto xs = sc.make_hot_observable({
+            on.next(150, 1),
+            on.completed(250)
+        });
+
+        WHEN("timestamp operator is invoked"){
+
+            auto res = w.start(
+                [so, xs]() {
+                    return xs.timestamp();
+                }
+            );
+
+            THEN("the output only contains complete message"){
+                auto required = rxu::to_vector({
+                    on_timestamp.completed(250)
+                });
+                auto actual = res.get_observer().messages();
+                REQUIRE(required == actual);
+            }
+
+            THEN("there was 1 subscription/unsubscription to the source"){
+                auto required = rxu::to_vector({
+                    on.subscribe(200, 250)
+                });
+                auto actual = xs.subscriptions();
+                REQUIRE(required == actual);
+            }
+
+        }
+    }
+}
+
+SCENARIO("should emit timestamped items for every item in the source observable", "[timestamp][operators]"){
+    GIVEN("a source"){
+        typedef typename rxsc::detail::test_type::clock_type clock_type;
+        typedef typename clock_type::time_point time_point;
+
+        auto sc = rxsc::make_test();
+        auto so = rx::synchronize_in_one_worker(sc);
+        auto w = sc.create_worker();
+        const rxsc::test::messages<int> on;
+        const rxsc::test::messages<std::pair<int, time_point>> on_timestamp;
+
+        auto xs = sc.make_hot_observable({
+            on.next(150, 1),
+            on.next(210, 2),
+            on.next(240, 3),
+            on.completed(250)
+        });
+
+        WHEN("timestamp operator is invoked"){
+
+            auto res = w.start(
+                [so, xs]() {
+                    return xs.timestamp(so);
+                }
+            );
+
+            THEN("the output contains the emitted items while subscribed"){
+                auto required = rxu::to_vector({
+                    on_timestamp.next(210, std::make_pair(2, clock_type::time_point(milliseconds(210)))),
+                    on_timestamp.next(240, std::make_pair(3, clock_type::time_point(milliseconds(240)))),
+                    on_timestamp.completed(250)
+                });
+                auto actual = res.get_observer().messages();
+                REQUIRE(required == actual);
+            }
+
+            THEN("there was 1 subscription/unsubscription to the source"){
+                auto required = rxu::to_vector({
+                    on.subscribe(200, 250)
+                });
+                auto actual = xs.subscriptions();
+                REQUIRE(required == actual);
+            }
+
+        }
+    }
+}
+
+SCENARIO("should emit timestamped items and an error if there is an error", "[timestamp][operators]"){
+    GIVEN("a source"){
+        typedef typename rxsc::detail::test_type::clock_type clock_type;
+        typedef typename clock_type::time_point time_point;
+
+        auto sc = rxsc::make_test();
+        auto so = rx::synchronize_in_one_worker(sc);
+        auto w = sc.create_worker();
+        const rxsc::test::messages<int> on;
+        const rxsc::test::messages<std::pair<int, time_point>> on_timestamp;
+
+        std::runtime_error ex("on_error from source");
+
+        auto xs = sc.make_hot_observable({
+            on.next(150, 1),
+            on.next(210, 2),
+            on.next(240, 3),
+            on.error(250, ex)
+        });
+
+        WHEN("timestamp operator is invoked"){
+
+            auto res = w.start(
+                [so, xs]() {
+                    return xs.timestamp(so);
+                }
+            );
+
+            THEN("the output contains emitted items and an error"){
+                auto required = rxu::to_vector({
+                    on_timestamp.next(210, std::make_pair(2, clock_type::time_point(milliseconds(210)))),
+                    on_timestamp.next(240, std::make_pair(3, clock_type::time_point(milliseconds(240)))),
+                    on_timestamp.error(250, ex)
+                });
+                auto actual = res.get_observer().messages();
+                REQUIRE(required == actual);
+            }
+
+            THEN("there was 1 subscription/unsubscription to the source"){
+                auto required = rxu::to_vector({
+                    on.subscribe(200, 250)
+                });
+                auto actual = xs.subscriptions();
+                REQUIRE(required == actual);
+            }
+
+        }
+    }
+}