/// <summary>
/// Creates and writes the initial commit context to a file.
/// </summary>
/// <param name="commitCount">The counter.</param>
/// <param name="fileSystemCount">The number of file systems being committed.</param>
/// <returns>The <see cref="Result"/> of the operation.</returns>
public Result Create(long commitCount, int fileSystemCount)
{
IFile contextFile = null;
try
{
// Open context file and create if it doesn't exist
Result rc = _fileSystem.OpenFile(out contextFile, CommitContextFileName, OpenMode.Read);
if (rc.IsFailure())
{
if (!ResultFs.PathNotFound.Includes(rc))
{
return(rc);
}
rc = _fileSystem.CreateFile(CommitContextFileName, CommitContextFileSize, CreateFileOptions.None);
if (rc.IsFailure())
{
return(rc);
}
rc = _fileSystem.OpenFile(out contextFile, CommitContextFileName, OpenMode.Read);
if (rc.IsFailure())
{
return(rc);
}
}
}
finally
{
contextFile?.Dispose();
}
try
{
Result rc = _fileSystem.OpenFile(out contextFile, CommitContextFileName, OpenMode.ReadWrite);
if (rc.IsFailure())
{
return(rc);
}
_context.Version = CurrentCommitContextVersion;
_context.State = CommitState.NotCommitted;
_context.FileSystemCount = fileSystemCount;
_context.Counter = commitCount;
// Write the initial context to the file
rc = contextFile.Write(0, SpanHelpers.AsByteSpan(ref _context), WriteOption.None);
if (rc.IsFailure())
{
return(rc);
}
rc = contextFile.Flush();
if (rc.IsFailure())
{
return(rc);
}
}
finally
{
contextFile?.Dispose();
}
return(_fileSystem.Commit());
}
/// <summary>
/// Recovers a multi-commit that was interrupted after all file systems had been provisionally committed.
/// The recovery will finish committing any file systems that are still provisionally committed.
/// </summary>
/// <param name="multiCommitInterface">The core interface used for multi-commits.</param>
/// <param name="contextFs">The file system containing the multi-commit context file.</param>
/// <param name="saveService">The save data service.</param>
/// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
/// <see cref="ResultFs.InvalidMultiCommitContextVersion"/>: The version of the commit context
/// file isn't supported.<br/>
/// <see cref="ResultFs.InvalidMultiCommitContextState"/>: The multi-commit hadn't finished
/// provisionally committing all the file systems.</returns>
private static Result RecoverCommit(ISaveDataMultiCommitCoreInterface multiCommitInterface,
IFileSystem contextFs, SaveDataFileSystemServiceImpl saveService)
{
IFile contextFile = null;
try
{
// Read the multi-commit context
Result rc = contextFs.OpenFile(out contextFile, CommitContextFileName, OpenMode.ReadWrite);
if (rc.IsFailure())
{
return(rc);
}
Unsafe.SkipInit(out Context context);
rc = contextFile.Read(out _, 0, SpanHelpers.AsByteSpan(ref context), ReadOption.None);
if (rc.IsFailure())
{
return(rc);
}
// Note: Nintendo doesn't check if the proper amount of bytes were read, but it
// doesn't really matter since the context is validated.
if (context.Version > CurrentCommitContextVersion)
{
return(ResultFs.InvalidMultiCommitContextVersion.Log());
}
// All the file systems in the multi-commit must have been at least provisionally committed
// before we can try to recover the commit.
if (context.State != CommitState.ProvisionallyCommitted)
{
return(ResultFs.InvalidMultiCommitContextState.Log());
}
// Keep track of the first error that occurs during the recovery
Result recoveryResult = Result.Success;
int saveCount = 0;
Span <SaveDataInfo> savesToRecover = stackalloc SaveDataInfo[MaxFileSystemCount];
SaveDataIndexerAccessor accessor = null;
ReferenceCountedDisposable <SaveDataInfoReaderImpl> infoReader = null;
try
{
rc = saveService.OpenSaveDataIndexerAccessor(out accessor, out _, SaveDataSpaceId.User);
if (rc.IsFailure())
{
return(rc);
}
rc = accessor.Indexer.OpenSaveDataInfoReader(out infoReader);
if (rc.IsFailure())
{
return(rc);
}
// Iterate through all the saves to find any provisionally committed save data
while (true)
{
Unsafe.SkipInit(out SaveDataInfo info);
rc = infoReader.Target.Read(out long readCount, OutBuffer.FromStruct(ref info));
if (rc.IsFailure())
{
return(rc);
}
// Break once we're done iterating all save data
if (readCount == 0)
{
break;
}
rc = multiCommitInterface.IsProvisionallyCommittedSaveData(out bool isProvisionallyCommitted,
in info);
// Note: Some saves could be missed if there are more than MaxFileSystemCount
// provisionally committed saves. Not sure why Nintendo doesn't catch this.
if (rc.IsSuccess() && isProvisionallyCommitted && saveCount < MaxFileSystemCount)
{
savesToRecover[saveCount] = info;
saveCount++;
}
}
}
finally
{
accessor?.Dispose();
infoReader?.Dispose();
}
// Recover the saves by finishing their commits.
// All file systems will try to be recovered, even if one fails.
// If any commits fail, the result from the first failed recovery will be returned.
for (int i = 0; i < saveCount; i++)
{
rc = multiCommitInterface.RecoverProvisionallyCommittedSaveData(in savesToRecover[i], false);
if (recoveryResult.IsSuccess() && rc.IsFailure())
{
recoveryResult = rc;
}
}
return(recoveryResult);
}
finally
{
contextFile?.Dispose();
}
}