TaskTree: Introduce Storage item

The Storage item makes it possible to define the whole
subtree as a self-contained, full-functional recipe, without a need
for passing (together with recipe) a one-use only (disposable)
pointer to storage object.

That's the last closing element of making the idea of pure,
value-based recipe real. It makes the TaskTree machinery ultimately
powerful.

Change-Id: Icd81bdd3e94251e8b241b2b550957d566fa4ab75
Reviewed-by: hjk <hjk@qt.io>

2 files changed, 111 insertions, 20 deletions

diff --git a/src/libs/utils/tasktree.cpp b/src/libs/utils/tasktree.cpp
index c99729a5d8..557b922ec7 100644
--- a/src/libs/utils/tasktree.cpp
+++ b/src/libs/utils/tasktree.cpp
@@ -117,6 +117,9 @@ void TaskItem::addChildren(const QList<TaskItem> &children)
             if (child.m_groupHandler.m_dynamicSetupHandler)
                 m_groupHandler.m_dynamicSetupHandler = child.m_groupHandler.m_dynamicSetupHandler;
             break;
+        case Type::Storage:
+            m_storageList.append(child.m_storageList);
+            break;
         }
     }
 }
@@ -144,11 +147,18 @@ public:
     void resetSuccessBit();
     void updateSuccessBit(bool success);
 
+    void createStorages();
+    void deleteStorages();
+    void activateStorages();
+    void deactivateStorages();
+
     TaskTreePrivate *m_taskTreePrivate = nullptr;
     TaskContainer *m_parentContainer = nullptr;
     const ExecuteMode m_executeMode = ExecuteMode::Parallel;
     WorkflowPolicy m_workflowPolicy = WorkflowPolicy::StopOnError;
     const TaskItem::GroupHandler m_groupHandler;
+    QList<TreeStorageBase> m_storageList;
+    QList<int> m_storageIdList;
     int m_taskCount = 0;
     GroupConfig m_groupConfig;
     QList<TaskNode *> m_children;
@@ -157,6 +167,22 @@ public:
     bool m_successBit = true;
 };
 
+class StorageActivator
+{
+public:
+    StorageActivator(TaskContainer &container)
+        : m_container(container)
+    {
+        m_container.activateStorages();
+    }
+    ~StorageActivator()
+    {
+        m_container.deactivateStorages();
+    }
+private:
+    TaskContainer &m_container;
+};
+
 class TaskNode : public QObject
 {
 public:
@@ -244,6 +270,7 @@ TaskContainer::TaskContainer(TaskTreePrivate *taskTreePrivate, TaskContainer *pa
     , m_executeMode(task.executeMode())
     , m_workflowPolicy(task.workflowPolicy())
     , m_groupHandler(task.groupHandler())
+    , m_storageList(task.storageList())
 {
     const QList<TaskItem> &children = task.children();
     for (const TaskItem &child : children) {
@@ -264,14 +291,18 @@ void TaskContainer::start()
     m_groupConfig = {};
     m_selectedChildren.clear();
 
-    if (m_groupHandler.m_setupHandler) {
-        GuardLocker locker(m_taskTreePrivate->m_guard);
-        m_groupHandler.m_setupHandler();
-    }
+    createStorages();
+    {
+        StorageActivator activator(*this);
+        if (m_groupHandler.m_setupHandler) {
+            GuardLocker locker(m_taskTreePrivate->m_guard);
+            m_groupHandler.m_setupHandler();
+        }
 
-    if (m_groupHandler.m_dynamicSetupHandler) {
-        GuardLocker locker(m_taskTreePrivate->m_guard);
-        m_groupConfig = m_groupHandler.m_dynamicSetupHandler();
+        if (m_groupHandler.m_dynamicSetupHandler) {
+            GuardLocker locker(m_taskTreePrivate->m_guard);
+            m_groupConfig = m_groupHandler.m_dynamicSetupHandler();
+        }
     }
 
     if (m_groupConfig.action == GroupAction::StopWithDone || m_groupConfig.action == GroupAction::StopWithError) {
@@ -374,13 +405,17 @@ void TaskContainer::invokeEndHandler(bool success, bool propagateToParent)
 {
     m_currentIndex = -1;
     m_successBit = success;
-    if (success && m_groupHandler.m_doneHandler) {
-        GuardLocker locker(m_taskTreePrivate->m_guard);
-        m_groupHandler.m_doneHandler();
-    } else if (!success && m_groupHandler.m_errorHandler) {
-        GuardLocker locker(m_taskTreePrivate->m_guard);
-        m_groupHandler.m_errorHandler();
+    {
+        StorageActivator activator(*this);
+        if (success && m_groupHandler.m_doneHandler) {
+            GuardLocker locker(m_taskTreePrivate->m_guard);
+            m_groupHandler.m_doneHandler();
+        } else if (!success && m_groupHandler.m_errorHandler) {
+            GuardLocker locker(m_taskTreePrivate->m_guard);
+            m_groupHandler.m_errorHandler();
+        }
     }
+    deleteStorages();
 
     if (!propagateToParent)
         return;
@@ -420,6 +455,46 @@ void TaskContainer::updateSuccessBit(bool success)
     }
 }
 
+void TaskContainer::createStorages()
+{
+    // TODO: Don't create new storage for already created storages with the same shared pointer.
+
+    for (int i = 0; i < m_storageList.size(); ++i)
+        m_storageIdList << m_storageList[i].createStorage();
+}
+
+void TaskContainer::deleteStorages()
+{
+    // TODO: Do the opposite
+
+    for (int i = 0; i < m_storageList.size(); ++i) // iterate in reverse order?
+        m_storageList[i].deleteStorage(m_storageIdList.value(i));
+
+    m_storageIdList.clear();
+}
+
+void TaskContainer::activateStorages()
+{
+    // TODO: check if the same shared storage was already activated. Don't activate recursively.
+
+    if (m_parentContainer)
+        m_parentContainer->activateStorages();
+
+    for (int i = 0; i < m_storageList.size(); ++i)
+        m_storageList[i].activateStorage(m_storageIdList.value(i));
+}
+
+void TaskContainer::deactivateStorages()
+{
+    // TODO: Do the opposite
+
+    for (int i = 0; i < m_storageList.size(); ++i) // iterate in reverse order?
+        m_storageList[i].activateStorage(0);
+
+    if (m_parentContainer)
+        m_parentContainer->deactivateStorages();
+}
+
 bool TaskNode::start()
 {
     if (!isTask()) {
@@ -428,16 +503,20 @@ bool TaskNode::start()
     }
     m_task.reset(m_taskHandler.m_createHandler());
     {
+        StorageActivator activator(m_container);
         GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
         m_taskHandler.m_setupHandler(*m_task.get());
     }
     connect(m_task.get(), &TaskInterface::done, this, [this](bool success) {
-        if (success && m_taskHandler.m_doneHandler) {
-            GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
-            m_taskHandler.m_doneHandler(*m_task.get());
-        } else if (!success && m_taskHandler.m_errorHandler) {
-            GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
-            m_taskHandler.m_errorHandler(*m_task.get());
+        {
+            StorageActivator activator(m_container);
+            if (success && m_taskHandler.m_doneHandler) {
+                GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
+                m_taskHandler.m_doneHandler(*m_task.get());
+            } else if (!success && m_taskHandler.m_errorHandler) {
+                GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
+                m_taskHandler.m_errorHandler(*m_task.get());
+            }
         }
         m_container.m_taskTreePrivate->advanceProgress(1);
 
@@ -465,6 +544,7 @@ void TaskNode::stop()
     // TODO: cancelHandler?
     // TODO: call TaskInterface::stop() ?
     if (m_taskHandler.m_errorHandler) {
+        StorageActivator activator(m_container);
         GuardLocker locker(m_container.m_taskTreePrivate->m_guard);
         m_taskHandler.m_errorHandler(*m_task.get());
     }
diff --git a/src/libs/utils/tasktree.h b/src/libs/utils/tasktree.h
index 9f54d6a3da..1cd6c53330 100644
--- a/src/libs/utils/tasktree.h
+++ b/src/libs/utils/tasktree.h
@@ -143,15 +143,16 @@ public:
     TaskHandler taskHandler() const { return m_taskHandler; }
     GroupHandler groupHandler() const { return m_groupHandler; }
     QList<TaskItem> children() const { return m_children; }
+    QList<TreeStorageBase> storageList() const { return m_storageList; }
 
 protected:
     enum class Type {
         Group,
+        Storage,
         Mode,
         Policy,
         TaskHandler,
         GroupHandler
-        // TODO: Add Cond type (with CondHandler and True and False branches)?
     };
 
     TaskItem() = default;
@@ -167,6 +168,9 @@ protected:
     TaskItem(const GroupHandler &handler)
         : m_type(Type::GroupHandler)
         , m_groupHandler(handler) {}
+    TaskItem(const TreeStorageBase &storage)
+        : m_type(Type::Storage)
+        , m_storageList{storage} {}
     void addChildren(const QList<TaskItem> &children);
 
 private:
@@ -175,6 +179,7 @@ private:
     WorkflowPolicy m_workflowPolicy = WorkflowPolicy::StopOnError;
     TaskHandler m_taskHandler;
     GroupHandler m_groupHandler;
+    QList<TreeStorageBase> m_storageList;
     QList<TaskItem> m_children;
 };
 
@@ -185,6 +190,12 @@ public:
     Group(std::initializer_list<TaskItem> children) { addChildren(children); }
 };
 
+class QTCREATOR_UTILS_EXPORT Storage : public TaskItem
+{
+public:
+    Storage(const TreeStorageBase &storage) : TaskItem(storage) { }
+};
+
 class QTCREATOR_UTILS_EXPORT Execute : public TaskItem
 {
 public: