9 files changed, 461 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 514895f..3f86163 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,4 +55,7 @@ add_subdirectory(dummyresource)
 # some tests
 add_subdirectory(tests)
 
+# async library prototype
+add_subdirectory(async)
+
 feature_summary(WHAT ALL FATAL_ON_MISSING_REQUIRED_PACKAGES)
diff --git a/async/CMakeLists.txt b/async/CMakeLists.txt
new file mode 100644
index 0000000..19ac407
--- /dev/null
+++ b/async/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_subdirectory(src)
+add_subdirectory(autotests)
\ No newline at end of file
diff --git a/async/autotests/CMakeLists.txt b/async/autotests/CMakeLists.txt
new file mode 100644
index 0000000..a2bedc8
--- /dev/null
+++ b/async/autotests/CMakeLists.txt
@@ -0,0 +1,5 @@
+include_directories(../src ${CMAKE_CURRENT_BINARY_DIR})
+
+add_executable(asynctest asynctest.cpp)
+qt5_use_modules(asynctest Test)
+target_link_libraries(asynctest akonadi2async Qt5::Core Qt5::Test)
\ No newline at end of file
diff --git a/async/autotests/asynctest.cpp b/async/autotests/asynctest.cpp
new file mode 100644
index 0000000..f2a70a4
--- /dev/null
+++ b/async/autotests/asynctest.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "../src/async.h"
+
+#include <QObject>
+#include <QString>
+#include <QTimer>
+#include <QtTest/QTest>
+
+class AsyncTest : public QObject
+{
+    Q_OBJECT
+
+public:
+    AsyncTest()
+    {}
+
+    ~AsyncTest()
+    {}
+
+private Q_SLOTS:
+    void testSyncPromises();
+    void testAsyncPromises();
+};
+
+void AsyncTest::testSyncPromises()
+{
+    auto baseJob = Async::start<int>(
+        []() -> Async::Future<int> {
+            auto f = Async::Future<int>(42);
+            f.setFinished();
+            return f;
+        })
+    .then<QString, int>(
+        [](int v) -> Async::Future<QString> {
+            auto f = Async::Future<QString>("Result is " + QString::number(v));
+            f.setFinished();
+            return f;
+        });
+
+    auto job = baseJob.then<QString, QString>(
+        [](const QString &v) -> Async::Future<QString> {
+            auto f = Async::Future<QString>(v.toUpper());
+            f.setFinished();
+            return f;
+        });
+
+    job.exec();
+    Async::Future<QString> future = job.result();
+
+    QCOMPARE(future.value(), QString::fromLatin1("RESULT IS 42"));
+}
+
+void AsyncTest::testAsyncPromises()
+{
+    auto job = Async::start<int>(
+      []() -> Async::Future<int> {
+          Async::Future<int> future(-1);
+          QTimer *timer = new QTimer();
+          QObject::connect(timer, &QTimer::timeout,
+                           [&]() {
+                              future.setValue(42);
+                              future.setFinished();
+                              timer->deleteLater();
+                           });
+          timer->setSingleShot(true);
+          timer->start(200);
+          return future;
+      });
+
+    job.exec();
+    Async::Future<int> future = job.result();
+    QCOMPARE(future.value(), 42);
+}
+
+
+QTEST_MAIN(AsyncTest);
+
+#include "asynctest.moc"
diff --git a/async/src/CMakeLists.txt b/async/src/CMakeLists.txt
new file mode 100644
index 0000000..a98d8ce
--- /dev/null
+++ b/async/src/CMakeLists.txt
@@ -0,0 +1,6 @@
+set(async_SRCS
+    async.cpp
+)
+
+add_library(akonadi2async SHARED ${async_SRCS})
+target_link_libraries(akonadi2async Qt5::Core)
diff --git a/async/src/async.cpp b/async/src/async.cpp
new file mode 100644
index 0000000..5c89e53
--- /dev/null
+++ b/async/src/async.cpp
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "async.h"
+
+#include <QCoreApplication>
+#include <QDebug>
+#include <QEventLoop>
+
+
+using namespace Async;
+
+FutureBase::FutureBase()
+    : mFinished(false)
+    , mWaitLoop(nullptr)
+{
+
+}
+
+FutureBase::FutureBase(const Async::FutureBase &other)
+    : mFinished(other.mFinished)
+    , mWaitLoop(other.mWaitLoop)
+{
+}
+
+void FutureBase::setFinished()
+{
+    mFinished = true;
+    if (mWaitLoop && mWaitLoop->isRunning()) {
+        mWaitLoop->quit();
+    }
+}
+
+bool FutureBase::isFinished() const
+{
+    return mFinished;
+}
+
+void FutureBase::waitForFinished()
+{
+    if (mFinished) {
+        return;
+    }
+
+    mWaitLoop = new QEventLoop;
+    mWaitLoop->exec(QEventLoop::ExcludeUserInputEvents);
+    delete mWaitLoop;
+    mWaitLoop = 0;
+}
diff --git a/async/src/async.h b/async/src/async.h
new file mode 100644
index 0000000..790dfe9
--- /dev/null
+++ b/async/src/async.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ASYNC_H
+#define ASYNC_H
+
+#include <functional>
+#include <list>
+#include <type_traits>
+#include <iostream>
+#include <cassert>
+
+#include "future.h"
+#include "async_impl.h"
+
+
+namespace Async {
+
+template<typename Out, typename ... In>
+class Job;
+
+template<typename Out, typename ... In>
+Job<Out, In ...> start(const std::function<Async::Future<Out>(In ...)> &func);
+
+
+class JobBase
+{
+public:
+    JobBase(JobBase *prev = nullptr)
+    : mPrev(prev)
+    , mResult(0)
+    {}
+
+    virtual void exec() = 0;
+
+public:
+    JobBase *mPrev;
+    void *mResult;
+};
+
+namespace Private {
+
+    template<typename Out, typename In>
+    typename std::enable_if<!std::is_void<In>::value, void>::type
+    doExec(JobBase *prev, JobBase *jobBase);
+
+    template<typename Out, typename ... In>
+    typename std::enable_if<sizeof...(In) == 0, void>::type
+    doExec(JobBase *prev, JobBase *jobBase, int * /* disambiguate */ = 0);
+}
+
+template<typename Out, typename ... In>
+class Job : public JobBase
+{
+    template<typename Out_, typename ... In_>
+    friend class Job;
+
+    template<typename Out_, typename ... In_, typename F_>
+    friend Job<Out_, In_ ...> start(F_ func);
+
+public:
+    ~Job()
+    {
+        // Can't delete in JobBase, since we don't know the type
+        // and deleting void* is undefined
+        delete reinterpret_cast<Async::Future<Out>*>(mResult);
+    }
+
+    template<typename Out_, typename ... In_, typename F>
+    Job<Out_, In_ ...> then(F func)
+    {
+        Job<Out_, In_ ...> job(this);
+        job.mFunc = func;
+        return job;
+    }
+
+    Async::Future<Out> result() const
+    {
+        return *reinterpret_cast<Async::Future<Out>*>(mResult);
+    }
+
+
+    void exec()
+    {
+        Async::Private::doExec<Out, In ...>(mPrev, this);
+    }
+
+private:
+    Job(JobBase *parent = nullptr)
+        : JobBase(parent)
+    {}
+
+public:
+    std::function<Async::Future<Out>(In ...)> mFunc;
+};
+
+template<typename Out, typename ... In, typename F>
+Job<Out, In ...> start(F func)
+{
+    Job<Out, In ...> job;
+    job.mFunc = std::function<Async::Future<Out>(In ...)>(func);
+    return job;
+}
+
+} // namespace Async
+
+template<typename Out, typename In>
+typename std::enable_if<!std::is_void<In>::value, void>::type
+Async::Private::doExec(JobBase *prev, JobBase *jobBase)
+{
+    prev->exec();
+    Async::Future<In> *in = reinterpret_cast<Async::Future<In>*>(prev->mResult);
+    assert(in->isFinished());
+
+    Job<Out, In> *job = dynamic_cast<Job<Out, In>*>(jobBase);
+    Async::Future<Out> *out = new Async::Future<Out>(job->mFunc(in->value()));
+    out->waitForFinished();
+    job->mResult = reinterpret_cast<void*>(out);
+};
+
+template<typename Out, typename ... In>
+typename std::enable_if<sizeof...(In) == 0, void>::type
+Async::Private::doExec(JobBase *prev, JobBase *jobBase, int * /* disambiguation */ = 0)
+{
+    if (prev) {
+        prev->exec();
+        Async::Future<void> *in = reinterpret_cast<Async::Future<void>*>(prev->mResult);
+        assert(in->isFinished());
+    }
+
+    Job<Out> *job = dynamic_cast<Job<Out>*>(jobBase);
+    Async::Future<Out> *out = new Async::Future<Out>(job->mFunc());
+    out->waitForFinished();
+    job->mResult = reinterpret_cast<void*>(out);
+};
+
+
+#endif // ASYNC_H
+
+
diff --git a/async/src/async_impl.h b/async/src/async_impl.h
new file mode 100644
index 0000000..46bc25d
--- /dev/null
+++ b/async/src/async_impl.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ASYNC_IMPL_H
+#define ASYNC_IMPL_H
+
+#include "async.h"
+
+namespace Async {
+
+
+} // namespace Async
+
+#endif // ASYNC_IMPL_H
\ No newline at end of file
diff --git a/async/src/future.h b/async/src/future.h
new file mode 100644
index 0000000..c53ef56
--- /dev/null
+++ b/async/src/future.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License or (at your option) version 3 or any later version
+ * accepted by the membership of KDE e.V. (or its successor approved
+ * by the membership of KDE e.V.), which shall act as a proxy
+ * defined in Section 14 of version 3 of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef FUTURE_H
+#define FUTURE_H
+
+class QEventLoop;
+
+namespace Async {
+
+class FutureBase
+{
+public:
+    FutureBase();
+    FutureBase(const FutureBase &other);
+    void setFinished();
+    bool isFinished() const;
+    void waitForFinished();
+
+protected:
+    bool mFinished;
+    QEventLoop *mWaitLoop;
+};
+
+template<typename T>
+class Future : public FutureBase
+{
+public:
+    Future()
+        : FutureBase()
+    {}
+
+    Future(const Future<T> &other)
+        : FutureBase(other)
+        , mValue(other.mValue)
+    {}
+
+    Future(const T &val)
+        : FutureBase()
+        , mValue(val)
+    {}
+
+    void setValue(const T &val)
+    {
+        mValue = val;
+    }
+
+    T value() const
+    {
+        return mValue;
+    }
+
+private:
+    T mValue;
+};
+
+template<>
+class Future<void> : public FutureBase
+{
+public:
+    Future()
+        : FutureBase()
+    {}
+
+    Future(const Future<void> &other)
+        : FutureBase(other)
+    {}
+};
+
+} // namespace Async
+
+#endif // FUTURE_H