libcore: Banks can decide whether to serialize individual items

If a serialized version of the data already exists, there’s no point in rewriting it.
skyjake · Feb 15, 2017 · c081590 · c081590
1 parent 78a9452
commit c081590
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Showing 4 changed files with 31 additions and 13 deletions.
diff --git a/doomsday/sdk/libcore/include/de/data/bank.h b/doomsday/sdk/libcore/include/de/data/bank.h
@@ -170,11 +170,12 @@ class DENG2_PUBLIC Bank
     public:
         virtual ~IData() {}
 
-        enum SerialMode { Serializing, Deserializing };
+        /// Serialization should be done?
+        virtual bool shouldBeSerialized() const { return true; }
 
         /// Returns an ISerializable pointer to the object. Required
         /// for putting the data in hot storage.
-        virtual ISerializable *asSerializable(SerialMode) { return 0; }
+        virtual ISerializable *asSerializable() { return 0; }
 
         /// Returns the size of the data that it occupies in memory.
         virtual duint sizeInMemory() const { return 0; }

diff --git a/doomsday/sdk/libcore/src/data/bank.cpp b/doomsday/sdk/libcore/src/data/bank.cpp
@@ -222,7 +222,7 @@ DENG2_PIMPL(Bank)
                 if (isValidSerialTime(timestamp))
                 {
                     std::unique_ptr<IData> blank(bank->newData());
-                    reader >> *blank->asSerializable(IData::Deserializing);
+                    reader >> *blank->asSerializable();
                     setData(blank.release());
                     LOG_RES_XVERBOSE("Deserialized \"%s\" in %.2f seconds",
                                      path(bank->d->sepChar) << startedAt.since());
@@ -258,21 +258,33 @@ DENG2_PIMPL(Bank)
                 loadFromSource();
             }
 
-            DENG2_ASSERT(data->asSerializable(IData::Serializing) != 0);
+            DENG2_ASSERT(data->asSerializable() != 0);
 
             try
             {
                 // Make sure the correct folder exists.
                 Folder &containingFolder = FileSystem::get()
                         .makeFolder(folderPath / path().toString().fileNamePath());
 
+                if (!data->shouldBeSerialized())
+                {
+                    // Not necessary; the serialized version already exists?
+                    if (File *existing = containingFolder.tryLocate<File>(name()))
+                    {
+                        serial.reset(existing);
+                        return;
+                    }
+                }
+
                 // Source timestamp is included in the serialization
                 // to check later whether the data is still fresh.
                 serial.reset(&containingFolder.newFile(name(), Folder::ReplaceExisting));
 
+                qDebug() << "Writing to cache:" << serial->description();
+
                 Writer(*serial).withHeader()
                         << source->modifiedAt()
-                        << *data->asSerializable(IData::Serializing);
+                        << *data->asSerializable();
             }
             catch (...)
             {

diff --git a/doomsday/sdk/libcore/src/filesys/metadatabank.cpp b/doomsday/sdk/libcore/src/filesys/metadatabank.cpp
@@ -33,12 +33,12 @@ DENG2_PIMPL(MetadataBank), public Lockable
     struct Data : public IData
     {
         Block metadata;
+        bool isChanged = false;
 
-        ISerializable *asSerializable(SerialMode mode) override {
-            if (mode == Serializing && metadata.isEmpty()) {
-                // Never serialize empty metadata, since it hasn't been set.
-                return nullptr;
-            }
+        bool shouldBeSerialized() const override {
+            return isChanged;
+        }
+        ISerializable *asSerializable() override {
             return &metadata;
         }
         virtual duint sizeInMemory() const override {
@@ -52,7 +52,7 @@ DENG2_PIMPL(MetadataBank), public Lockable
     {
         DENG2_ASSERT(!id.isEmpty());
         String const hex = id.asHexadecimalText();
-        return String("%1.%2.%3").arg(category).arg(hex.at(0)).arg(hex);
+        return String("%1.%2.%3").arg(category).arg(hex.last()).arg(hex);
     }
 };
 
@@ -87,7 +87,12 @@ void MetadataBank::setMetadata(String const &category, Block const &id, Block co
     {
         Bank::add(path, new Impl::Source(id));
     }
-    data(path).as<Impl::Data>().metadata = metadata;
+    auto &entry = data(path).as<Impl::Data>();
+    entry.metadata = metadata;
+    entry.isChanged = true;
+
+    qDebug() << "Set metadata for" << category << id.asHexadecimalText();
+    DENG2_PRINT_BACKTRACE();
 }
 
 Block MetadataBank::metadata(String const &category, Block const &id) const

diff --git a/doomsday/sdk/libgui/src/graphics/imagebank.cpp b/doomsday/sdk/libgui/src/graphics/imagebank.cpp
@@ -52,7 +52,7 @@ DENG2_PIMPL_NOREF(ImageBank)
         ImageData() {}
         ImageData(Image const &img) : image(img) {}
 
-        ISerializable *asSerializable(SerialMode)
+        ISerializable *asSerializable()
         {
             return &image;
         }