private FSHeader CreateFile()
{
var buffer = new byte[512];
var fsHeader = new FSHeader
{
AllocationBlock = AllocationBlockId,
RootDirectoryBlock = RootDirectoryBlockId,
FreeBlockCount = 0
};
storage.WriteBlock(0, new[] { fsHeader });
storage.WriteBlock(1, buffer);
buffer[0] = RootDirectoryDataBlockId;
storage.WriteBlock(2, buffer);
var fsRoot = new DirectoryHeader
{
FirstEmptyItemOffset = 1,
ItemsCount = 0,
LastNameOffset = 0,
NameBlockIndex = NameBlockIndex,
ParentDirectoryBlockIndex = RootDirectoryBlockId
};
storage.WriteBlock(RootDirectoryDataBlockId, new[] { new DirectoryHeaderRoot {
Header = fsRoot
} });
buffer[0] = 0;
storage.WriteBlock(NameBlockIndex, buffer);
return(fsHeader);
}
private void WriteHeader()
{
var fsHeader = new FSHeader
{
AllocationBlock = allocationManager.BlockId,
RootDirectoryBlock = RootDirectory.BlockId,
FreeBlockCount = allocationManager.ReleasedBlockCount
};
storage.WriteBlock(0, new[] { fsHeader });
}
private void InitializeFromHeader(IBlockStorage blockStorage, FSHeader header)
{
var allocationIndexFactory = new GenericFactory <IIndex <int>, IAllocationManager>(
m =>
{
var accessParameters = new CommonAccessParameters(blockStorage, m);
var allocationIndexProvider =
indexBlockProviderFactory.Create(header.AllocationBlock, accessParameters);
return(indexFactory.Create(allocationIndexProvider, accessParameters));
});
allocationManager = allocationManagerFactory.Create(allocationIndexFactory, blockStorage, header.FreeBlockCount);
var dictionaryCache = directoryCacheFactory.Create(new CommonAccessParameters(blockStorage, allocationManager));
var rootDirectory = dictionaryCache.ReadDirectory(header.RootDirectoryBlock);
RootDirectory = rootDirectory;
DirectoryCache = dictionaryCache;
}
public void Open(string fileName, OpenMode openMode)
{
if (fileName == null)
{
throw new ArgumentNullException(nameof(fileName));
}
if (isOpened)
{
throw new InvalidOperationException("File system is already opened");
}
storage = blockStorageFactory.Create(fileName);
storage.Open(openMode);
try
{
FSHeader header;
if (openMode == OpenMode.Create)
{
header = CreateFile();
}
else
{
var headers = new FSHeader[1];
storage.ReadBlock(0, headers);
header = headers[0];
}
InitializeFromHeader(storage, header);
}
catch
{
storage.Dispose();
}
isOpened = true;
}
