Combinator: Changed the parent type from Observable<QVariantList> to …

…Observable<void> and AsyncFuture do not use any QVariant type any more
benlau · Mar 21, 2017 · 0aab059 · 0aab059
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commit 0aab059
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Showing 4 changed files with 34 additions and 65 deletions.
diff --git a/README.md b/README.md
@@ -44,11 +44,11 @@ QFuture<QImage> f1 = QtConcurrent::run(readImage, QString("image.jpg"));
 
 QFuture<void> f2 = observe(timer, &QTimer::timeout).future();
 
-(combine() << f1 << f2).subscribe([](QVariantList result){
-    // Read an image
-    // result[0] = QImage
-    qDebug() << result;
-});
+QFuture<QImage> result = (combine() << f1 << f2).subscribe([=](){
+    // Read an image but do not return before timeout
+    return f1.result();
+}).future();
+
 ```
 
 **3. Advanced multi-threading model**

diff --git a/asyncfuture.h b/asyncfuture.h
@@ -4,7 +4,6 @@
 #include <QPointer>
 #include <QThread>
 #include <QFutureWatcher>
-#include <QVariant>
 #include <functional>
 
 namespace AsyncFuture {
@@ -241,23 +240,9 @@ class DeferredFuture : public QObject, public QFutureInterface<T>{
 
 };
 
-// Obtain the result of future in QVariant.
-// It is used within Combinator only as other component do not
-// require to register QMetaType
-template <typename T>
-inline QVariant obtainFutureResult(QFuture<T> future) {
-    return future.result();
-}
-
-template <>
-inline QVariant obtainFutureResult<void>(QFuture<void> future) {
-    Q_UNUSED(future);
-    return QVariant();
-}
-
-class CombinedFuture: public DeferredFuture<QVariantList> {
+class CombinedFuture: public DeferredFuture<void> {
 public:
-    CombinedFuture(bool settleAllMode = false) : DeferredFuture<QVariantList>(), settleAllMode(settleAllMode) {
+    CombinedFuture(bool settleAllMode = false) : DeferredFuture<void>(), settleAllMode(settleAllMode) {
         settledCount = 0;
         count = 0;
         anyCanceled = false;
@@ -269,12 +254,11 @@ class CombinedFuture: public DeferredFuture<QVariantList> {
             return;
         }
         int index = count++;
-        results << QVariant();
         incRefCount();
 
         Private::watch(future, this,
                        [=]() {
-            completeFutureAt(index, future);
+            completeFutureAt(index);
             decRefCount();
         },[=]() {
             cancelFutureAt(index);
@@ -286,7 +270,6 @@ class CombinedFuture: public DeferredFuture<QVariantList> {
     int count;
     bool anyCanceled;
     bool settleAllMode;
-    QVariantList results;
 
     static QSharedPointer<CombinedFuture> create(bool settleAllMode) {
 
@@ -306,10 +289,9 @@ class CombinedFuture: public DeferredFuture<QVariantList> {
 
 private:
 
-    template <typename T>
-    void completeFutureAt(int index, QFuture<T> future) {
+    void completeFutureAt(int index) {
+        Q_UNUSED(index);
         settledCount++;
-        results[index] = Private::obtainFutureResult(future);
         checkFulfilled();
     }
 
@@ -334,7 +316,7 @@ class CombinedFuture: public DeferredFuture<QVariantList> {
             if (anyCanceled) {
                 cancel();
             } else {
-                complete(results);
+                complete();
             }
         }
     }
@@ -492,6 +474,9 @@ void>::type
 voidInvoke(Functor functor, QFuture<T> future) {
     Q_UNUSED(future);
     functor();
+    /* Toubleshooting:
+     * 1) Are you observing a QFuture<void> but require an input argument in your callback function?
+     */
 }
 
 template <typename Functor, typename T>
@@ -706,12 +691,12 @@ class Deferred<void> : public Observable<void> {
     QSharedPointer<Private::DeferredFuture<void> > defer;
 };
 
-class Combinator : public Observable<QVariantList> {
+class Combinator : public Observable<void> {
 private:
     QSharedPointer<Private::CombinedFuture> combinedFuture;
 
 public:
-    inline Combinator(bool settleAllMode = false) : Observable<QVariantList>() {
+    inline Combinator(bool settleAllMode = false) : Observable<void>() {
         combinedFuture = Private::CombinedFuture::create(settleAllMode);
         m_future = combinedFuture->future();
     }

diff --git a/tests/asyncfutureunittests/asyncfuturetests.cpp b/tests/asyncfutureunittests/asyncfuturetests.cpp
@@ -674,66 +674,55 @@ void AsyncFutureTests::test_Combinator()
         auto d1 = deferred<int>();
         auto d2 = deferred<QString>();
         auto d3 = deferred<void>();
+        auto c = Callable<void>();
 
         auto combinator = combine();
         combinator << d1.future() << d2.future() << d3.future();
 
-        QFuture<QVariantList> future = combinator.future();
-        QVariantList results;
+        QFuture<void> future = combinator.future();
 
-        observe(future).subscribe([&](QVariantList value) {
-            results = value;
-        });
+        observe(future).subscribe(c.func);
 
         d1.complete(1);
         d2.complete("second");
         d3.complete();
 
-        QCOMPARE(results.isEmpty(), true);
+        QCOMPARE(c.called, false);
         QCOMPARE(future.isFinished(), false);
 
         QVERIFY(waitUntil(future,1000));
 
+        QCOMPARE(c.called, true);
         QCOMPARE(future.isFinished(), true);
-
-        QCOMPARE(results.size(), 3);
-        QVERIFY(results[0] == 1);
-        QVERIFY(results[1] == "second");
     }
 
 
     {
         // case: all completed (but Combinator was destroyed )
-        QFuture<QVariantList> future ;
+        QFuture<void> future ;
 
         auto d1 = deferred<int>();
         auto d2 = deferred<QString>();
         auto d3 = deferred<void>();
+        auto c = Callable<void>();
 
         {
             future = (combine() << d1.future() << d2.future() << d3.future()).future();
         }
 
-        QVariantList results;
-
-        observe(future).subscribe([&](QVariantList value) {
-            results = value;
-        });
+        observe(future).subscribe(c.func);
 
         d1.complete(1);
         d2.complete("second");
         d3.complete();
 
-        QCOMPARE(results.isEmpty(), true);
+        QCOMPARE(c.called, false);
         QCOMPARE(future.isFinished(), false);
 
         QVERIFY(waitUntil(future,1000));
 
         QCOMPARE(future.isFinished(), true);
-
-        QCOMPARE(results.size(), 3);
-        QVERIFY(results[0] == 1);
-        QVERIFY(results[1] == "second");
+        QCOMPARE(c.called, true);
     }
 
     {
@@ -745,7 +734,7 @@ void AsyncFutureTests::test_Combinator()
         auto combinator = combine();
         combinator << d1.future() << d2.future() << d3.future();
 
-        QFuture<QVariantList> future = combinator.future();
+        QFuture<void> future = combinator.future();
 
         Callable<void> canceled;
 
@@ -770,9 +759,9 @@ void AsyncFutureTests::test_Combinator()
         auto combinator = combine(true);
         combinator << d1.future() << d2.future() << d3.future();
 
-        QFuture<QVariantList> future = combinator.future();
+        QFuture<void> future = combinator.future();
 
-        Callable<QVariantList> completed;
+        Callable<void> completed;
         Callable<void> canceled;
 
         observe(future).subscribe(completed.func, canceled.func);
@@ -824,10 +813,6 @@ void AsyncFutureTests::test_Combinator_add_to_already_finished()
         d4.complete(true);
 
         QVERIFY(waitUntil(copy.future(), 1000)); // It is already resolved
-        QVERIFY(copy.future().isResultReadyAt(0));
-        QVariantList result = copy.future().result();
-        QCOMPARE(result.size(), 3);
-
     }
 
 }
diff --git a/tests/asyncfutureunittests/example.cpp b/tests/asyncfutureunittests/example.cpp
@@ -63,15 +63,14 @@ void Example::example_combine_multiple_future()
 
     QFuture<void> f2 = observe(timer, &QTimer::timeout).future();
 
-    (combine() << f1 << f2).subscribe([](QVariantList result){
-        // result[0] = QImage
-        qDebug() << result;
-    });
+    QFuture<QImage> result = (combine() << f1 << f2).subscribe([=](){
+        // Read an image but do not return before timeout
+        return f1.result();
+    }).future();
 
     timer->start();
 
-    waitUntil(f1);
-    waitUntil(f2);
+    QVERIFY(waitUntil(result, 1000));
 
     timer->deleteLater();
 }