Reading of individual revisions from the store

2 files changed, 33 insertions, 1 deletions

diff --git a/common/entitystore.cpp b/common/entitystore.cpp
index 2c15abf..5f44609 100644
--- a/common/entitystore.cpp
+++ b/common/entitystore.cpp
@@ -46,3 +46,19 @@ QSharedPointer<Sink::ApplicationDomain::BufferAdaptor> EntityStore::getLatest(co
     return current;
 }
 
+QSharedPointer<Sink::ApplicationDomain::BufferAdaptor> EntityStore::get(const Sink::Storage::NamedDatabase &db, const QByteArray &key, DomainTypeAdaptorFactoryInterface &adaptorFactory)
+{
+    QSharedPointer<Sink::ApplicationDomain::BufferAdaptor> current;
+    db.scan(key,
+        [&current, &adaptorFactory](const QByteArray &key, const QByteArray &data) -> bool {
+            Sink::EntityBuffer buffer(const_cast<const char *>(data.data()), data.size());
+            if (!buffer.isValid()) {
+                Warning() << "Read invalid buffer from disk";
+            } else {
+                current = adaptorFactory.createAdaptor(buffer.entity());
+            }
+            return false;
+        },
+        [](const Sink::Storage::Error &error) { Warning() << "Failed to read current value from storage: " << error.message; });
+    return current;
+}
diff --git a/common/entitystore.h b/common/entitystore.h
index 17156ec..b6f8713 100644
--- a/common/entitystore.h
+++ b/common/entitystore.h
@@ -38,12 +38,28 @@ public:
         auto typeName = ApplicationDomain::getTypeName<T>();
         auto mainDatabase = Storage::mainDatabase(mTransaction, typeName);
         auto bufferAdaptor = getLatest(mainDatabase, identifier, *Sink::AdaptorFactoryRegistry::instance().getFactory<T>(mResourceType));
-        Q_ASSERT(bufferAdaptor);
+        if (!bufferAdaptor) {
+            return T();
+        }
+        return T(mResourceInstanceIdentifier, identifier, 0, bufferAdaptor);
+    }
+
+    template<typename T>
+    T readFromKey(const QByteArray &key) const
+    {
+        auto typeName = ApplicationDomain::getTypeName<T>();
+        auto mainDatabase = Storage::mainDatabase(mTransaction, typeName);
+        auto bufferAdaptor = get(mainDatabase, key, *Sink::AdaptorFactoryRegistry::instance().getFactory<T>(mResourceType));
+        const auto identifier = Storage::uidFromKey(key);
+        if (!bufferAdaptor) {
+            return T();
+        }
         return T(mResourceInstanceIdentifier, identifier, 0, bufferAdaptor);
     }
 
 
     static QSharedPointer<Sink::ApplicationDomain::BufferAdaptor> getLatest(const Sink::Storage::NamedDatabase &db, const QByteArray &uid, DomainTypeAdaptorFactoryInterface &adaptorFactory);
+    static QSharedPointer<Sink::ApplicationDomain::BufferAdaptor> get(const Sink::Storage::NamedDatabase &db, const QByteArray &key, DomainTypeAdaptorFactoryInterface &adaptorFactory);
 private:
     QByteArray mResourceType;
     QByteArray mResourceInstanceIdentifier;