public override int Write(object fileNode,
object fileDesc,
IntPtr buffer,
ulong offset,
uint length,
bool writeToEndOfFile,
bool constrainedIo,
out uint bytesTransferred,
out FileInfo fileInfo)
{
if (fileNode is FileNode node &&
fileDesc is FileMetadata metadata)
{
Logger.LogTrace(
$"Request {nameof ( Write )} to \"{metadata . Name}\", start from {offset} with length {length}({( ( long ) length ) . BytesCountToHumanString ( )}).");
if (writeToEndOfFile)
{
offset = ( ulong )metadata.Size;
}
if (!constrainedIo)
{
ResizeFile(
node,
Math.Max(metadata.Size, ( long )offset + length));
length = ( uint )Math.Min(metadata.Size - ( long )offset, length);
}
int startBlockSequence = ( int )(offset / ( ulong )BlockSize);
int endBlockSequence =
( int )((offset + length + ( ulong )BlockSize - 1)
/ ( ulong )BlockSize);
int currentByteSequence = 0;
int currentBlockSequence = startBlockSequence;
CachedBlock currentBlock = node.GetBlock(currentBlockSequence);
#region firstBlock
int firstByteStartFrom = ( int )(offset % ( ulong )BlockSize);
int currentBlockCopyByteCount = ( int )Math.Min(
BlockSize - firstByteStartFrom,
length
- currentByteSequence);
currentBlock.IsModified = true;
Marshal.Copy(
buffer + currentByteSequence,
currentBlock.Content,
firstByteStartFrom,
currentBlockCopyByteCount);
currentByteSequence += currentBlockCopyByteCount;
currentBlockSequence++;
#endregion
firstByteStartFrom = 0;
for ( ; currentBlockSequence < endBlockSequence; currentBlockSequence++)
{
currentBlock = node.GetBlock(currentBlockSequence);
currentBlockCopyByteCount = ( int )Math.Min(
BlockSize - firstByteStartFrom,
length
- currentByteSequence);
currentBlock.IsModified = true;
Marshal.Copy(
buffer + currentByteSequence,
currentBlock.Content,
firstByteStartFrom,
currentBlockCopyByteCount);
currentByteSequence += currentBlockCopyByteCount;
}
bytesTransferred = ( uint )currentByteSequence;
fileInfo = metadata.FileInfo;
Logger.LogDebug(
$"Written to \"{metadata . Name}\", start from {offset} with length {bytesTransferred}({( ( long ) bytesTransferred ) . BytesCountToHumanString ( )}).");
return(STATUS_SUCCESS);
}
throw GetIoExceptionWithNtStatus(STATUS_INVALID_HANDLE);
}
public override int Read(object fileNode,
object fileDesc,
IntPtr buffer,
ulong offset,
uint length,
out uint bytesTransferred)
{
if (fileNode is FileNode node &&
fileDesc is FileMetadata metadata)
{
Logger.LogTrace(
$"Request {nameof ( Read )} from \"{metadata . Name}\", start from {offset} with length {length}({( ( long ) length ) . BytesCountToHumanString ( )}).");
if (offset >= ( ulong )metadata.Size)
{
bytesTransferred = default;
return(STATUS_END_OF_FILE);
}
length = ( uint )Math.Min(length, metadata.Size - ( long )offset);
int startBlockSequence = ( int )(offset / ( ulong )BlockSize);
int endBlockSequence =
( int )((offset + length + ( ulong )BlockSize - 1)
/ ( ulong )BlockSize);
endBlockSequence = Math.Min(
endBlockSequence,
metadata.AllocatedBlockCount - 1);
int currentByteSequence = 0;
int currentBlockSequence = startBlockSequence;
#region firstBlock
CachedBlock currentBlock = node.GetBlock(currentBlockSequence);
int firstByteStartFrom = ( int )(offset % ( ulong )BlockSize);
int currentBlockCopyByteCount = ( int )Math.Min(
BlockSize - firstByteStartFrom,
length
- currentByteSequence);
Marshal.Copy(
currentBlock.Content,
firstByteStartFrom,
buffer + currentByteSequence,
currentBlockCopyByteCount);
currentByteSequence += currentBlockCopyByteCount;
currentBlockSequence++;
#endregion
firstByteStartFrom = 0;
for ( ; currentBlockSequence < endBlockSequence; currentBlockSequence++)
{
currentBlock = node.GetBlock(currentBlockSequence);
currentBlockCopyByteCount = ( int )Math.Min(
BlockSize - firstByteStartFrom,
length
- currentByteSequence);
Marshal.Copy(
currentBlock.Content,
firstByteStartFrom,
buffer + currentByteSequence,
currentBlockCopyByteCount);
currentByteSequence += currentBlockCopyByteCount;
}
bytesTransferred = ( uint )currentByteSequence;
Logger.LogDebug(
$"Read from \"{metadata . Name}\", start from {offset} with length {bytesTransferred}({( ( long ) bytesTransferred ) . BytesCountToHumanString ( )}).");
return(STATUS_SUCCESS);
}
throw GetIoExceptionWithNtStatus(STATUS_INVALID_HANDLE);
}