Method UpgradeAsset

Source/Engine/Content/Factories/BinaryAssetFactory.cpp:114–214

#if USE_EDITOR

bool BinaryAssetFactoryBase::UpgradeAsset(const AssetInfo& info, FlaxStorage* storage, AssetMigrationContext& context)
{
    // Load all asset chunks
    for (int32 chunkIndex = 0; chunkIndex < ASSET_FILE_DATA_CHUNKS; chunkIndex++)
    {
        auto chunk = context.Input.Header.Chunks[chunkIndex];
        if (chunk && storage->LoadAssetChunk(chunk))
        {
            LOG(Warning, "Failed to load asset chunk {0}.", chunkIndex);
            return true;
        }
    }

    // Init output header
    context.Output.Header = context.Input.Header;

    // Start upgrading chain
    const auto upgrader = static_cast<BinaryAssetUpgrader*>(GetUpgrader());
    int32 step = 0;
    do
    {
        // Unlink chunks in output (won't be used)
        context.Output.Header.UnlinkChunks();

        // Perform conversion
        // Note: on failed conversion there may be some memory leaks but we don't care in that case very much
        if (upgrader->Upgrade(context.Input.SerializedVersion, context))
            return true;

        // Swap input with output (remember to delete old input chunks if they were allocated by upgrader not by the storage)
        if (step++ > 1)
            context.Input.Header.DeleteChunks();
        context.Input = context.Output;
    } while (upgrader->ShouldUpgrade(context.Input.SerializedVersion));

    // Prevent other threads from loading the storage when it is upgrading
    // It works because CriticalSection allows recursion
    ScopeLock upgradeLock(storage->_loadLocker);

    // Release storage internal data (should also close file handles)
    {
        // HACK: file is locked by some tasks: the current one that called asset data upgrade (LoadAssetTask)
        // and by asset data loading tasks which are waiting for the start after init task
        // Let's hide these locks just for the upgrade
        const auto locks = storage->_chunksLock;
        storage->_chunksLock = 0;
        storage->Dispose();
        storage->_chunksLock = locks;
    }

    // Serialize conversion result data
#if USE_EDITOR
    if (FlaxFile::Create(storage->GetPath(), context.Output))
#endif
    {
        LOG(Warning, "Cannot serialize converted data.");
        return true;
    }