Refactor how the storage is used.

This is the initial refactoring to improve how we deal with the storage.

It does a couple of things:
* Rename Sink::Storage to Sink::Storage::DataStore to free up the
  Sink::Storage namespace
* Introduce a Sink::ResourceContext to have a single object that can be
  passed around containing everything that is necessary to operate on a
  resource. This is a lot better than the multiple separate parameters
  that we used to pass around all over the place, while still allowing
  for dependency injection for tests.
* Tie storage access together using the new EntityStore that directly
  works with ApplicationDomainTypes. This gives us a central place where
  main storage, indexes and buffer adaptors are tied together, which
  will also give us a place to implement external indexes, such as a
  fulltextindex using xapian.
* Use ApplicationDomainTypes as the default way to pass around entities.
  Instead of using various ways to pass around entities (buffers,
  buffer adaptors, ApplicationDomainTypes), only use a single way.
  The old approach was confusing, and was only done as:
  * optimization; really shouldn't be necessary and otherwise I'm sure
  we can find better ways to optimize ApplicationDomainType itself.
  * a way to account for entities that have multiple buffers, a concept
  that I no longer deem relevant.

While this commit does the bulk of the work to get there, the following
commits will refactor more stuff to get things back to normal.

1 files changed, 77 insertions, 0 deletions

diff --git a/common/resourcecontext.h b/common/resourcecontext.h
new file mode 100644
index 0000000..6058ac7
--- /dev/null
+++ b/common/resourcecontext.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2016 Christian Mollekopf <mollekopf@kolabsys.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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 6 of version 3 of the license.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include "domaintypeadaptorfactoryinterface.h"
+#include "applicationdomaintype.h"
+#include "resourceaccess.h"
+#include <QByteArray>
+#include <QMap>
+
+namespace Sink {
+
+/*
+ * A context object that can be passed around so each part of the system knows in what context it works.
+ *
+ * This is necessary because we can't rely on a singleton or thread-local storage since multiple resources can be accessed from the same thread/process.
+ */
+struct ResourceContext {
+    const QByteArray resourceInstanceIdentifier;
+    const QByteArray resourceType;
+    QMap<QByteArray, DomainTypeAdaptorFactoryInterface::Ptr> adaptorFactories;
+    //TODO prehaps use a weak pointer to not mess up lifetime management
+    ResourceAccessInterface::Ptr mResourceAccess;
+
+
+    ResourceContext(const QByteArray &identifier, const QByteArray &resourceType_, const QMap<QByteArray, DomainTypeAdaptorFactoryInterface::Ptr> &factories = QMap<QByteArray, DomainTypeAdaptorFactoryInterface::Ptr>())
+        : resourceInstanceIdentifier(identifier),
+        resourceType(resourceType_),
+        adaptorFactories(factories)
+    {
+    }
+
+    QByteArray instanceId() const
+    {
+        return resourceInstanceIdentifier;
+    }
+
+    DomainTypeAdaptorFactoryInterface &adaptorFactory(const QByteArray &type) const
+    {
+        auto factory = adaptorFactories.value(type);
+        Q_ASSERT(factory);
+        return *factory;
+    }
+
+    template<typename DomainType>
+    DomainTypeAdaptorFactoryInterface &adaptorFactory()
+    {
+        return adaptorFactory(ApplicationDomain::getTypeName<DomainType>());
+    }
+
+    ResourceAccessInterface::Ptr resourceAccess()
+    {
+        if (!mResourceAccess) {
+            mResourceAccess = ResourceAccessFactory::instance().getAccess(resourceInstanceIdentifier, resourceType);
+        }
+        return mResourceAccess;
+    }
+};
+
+}