XGameSaveSubmitUpdateAsync

Article
06/22/2023

Submit an update to the XGameSave service asynchronously. Updates blobs within a container.

Syntax

HRESULT XGameSaveSubmitUpdateAsync(  
         XGameSaveUpdateHandle updateContext,  
         XAsyncBlock* async  
)

Parameters

updateContext _In_
Type: XGameSaveUpdateHandle

A handle to the XGameSaveUpdate to be updated.

async _In_
Type: XAsyncBlock*

An AsyncBlock containing the calling context and callback function for the XGameSaveSubmitUpdateAsync call.

Return value

Type: HRESULT

Function result

Remarks

This function is called as a part of the AsyncBlock call function of XGameSaveSubmitUpdateAsync. This function will be used to determine the results of XGameSaveSubmitUpdateAsync.

The storage portion of this API is designed to easily transfer data from the game to persisted storage in a safe, reliable and transactional manner. We want to make sure the backing data for a container is always consistent and as such we want the whole operation to succeed or fail atomically. We don't want to have a partial update where some blob data is inconsistent with other data within the container. In order to do this we provide an update context that blob writes and deletes are submitted to and when that is ready the whole context is submitted. In practice this looks like the following:

An XGameSaveUpdate will be filled with Write and Delete actions to be carried out on blobs within the container by way of XGameSaveSubmitBlobWrite and XGameSaveSubmitBlobDelete. An update is completed by calling XGameSaveSubmitUpdateAsync.

When you are finished with an XGameSaveUpdate close it using the XGameSaveCloseUpdate method.

The following C++ sample demonstrates an asynchronous XGameSave update.

// ASYNC Write - can be kicked off from a time sensitive thread 
//               actual work and completion will be scheduled base upon 
//               the configuration of the async_queue tied to the XAsyncBlock. 
void Sample::_SaveDataAsync(const char* containerName, const char* containerDisplayName) 
{ 
    struct SaveContext 
    { 
        SaveContext(Sample* s) : self(s), containerContext(nullptr), updateContext(nullptr) {} 
        ~SaveContext() 
        { 
            if (updateContext) 
            { 
                XGameSaveCloseUpdate(updateContext); 
            } 
            if (containerContext) 
            { 
                XGameSaveCloseContainer(containerContext); 
            } 
        } 
  
        XAsyncBlock async; 
        XGameSaveContainerHandle containerContext; 
        XGameSaveUpdateHandle updateContext; 
        Sample* self; 
    }; 
  
    HRESULT hr; 
    SaveContext* saveContext = new SaveContext(this); 
    if (saveContext == nullptr) 
    { 
        hr = E_OUTOFMEMORY; 
    } 
    if (SUCCEEDED(hr)) 
    { 
        saveContext->async.context = saveContext; 
        saveContext->async.callback = [](XAsyncBlock* async) 
        { 
            auto ctx = reinterpret_cast<SaveContext*>(async->context); 
            auto self = ctx->self; 
            HRESULT hr = XGameSaveSubmitUpdateResult(async); 
            self->_HandleContainerUpdateErrors(hr); 
            delete ctx; 
        }; 
    } 
  
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveCreateContainer(_provider, containerName, &saveContext->containerContext); 
    } 
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveCreateUpdate(saveContext->containerContext, containerDisplayName, &saveContext->updateContext); 
    } 
  
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveSubmitBlobWrite(saveContext->updateContext, "WorldState", _worldState.data(), _worldState.size()); 
    } 
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveSubmitBlobWrite(saveContext->updateContext, "PlayerState", _playerState.data(), _playerState.size()); 
    } 
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveSubmitBlobWrite(saveContext->updateContext, "PlayerInventory", _playerInventory.data(), _playerInventory.size()); 
    } 
    if (SUCCEEDED(hr)) 
    { 
        if (_clearLevelProgress) 
        { 
            hr = XGameSaveSubmitBlobDelete(saveContext->updateContext, "LevelProgress"); 
        } 
    } 
    if (SUCCEEDED(hr)) 
    { 
        hr = XGameSaveSubmitUpdateAsync(saveContext->updateContext, &saveContext->async); 
    } 
    if (SUCCEEDED(hr)) 
    { 
        // context is now owned by the async 
        saveContext = nullptr; 
    } 
  
    // if there was any error we need to cleanup the saveContext 
    if (saveContext) 
    { 
        delete saveContext; 
    } 
  
}

Requirements

Header: XGameSave.h

Library: xgameruntime.lib

Supported platforms: Windows, Xbox One family consoles and Xbox Series consoles

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