// Writes data to a file (asynchronous overload).
AKRESULT CAkDefaultIOHookDeferred::Write(
AkFileDesc & in_fileDesc, // File descriptor.
const AkIoHeuristics & /*in_heuristics*/, // Heuristics for this data transfer (not used in this implementation).
AkAsyncIOTransferInfo & io_transferInfo // Platform-specific asynchronous IO operation info.
)
{
assert( in_fileDesc.hFile != INVALID_HANDLE_VALUE
&& io_transferInfo.uRequestedSize > 0 );
// If this assert comes up, it might be beacause this hook's GetBlockSize() return value is incompatible
// with the system's handling of file reading for this specific file handle.
// Are you using the File Package Low-Level I/O with incompatible block size? (check -blocksize argument in the File Packager command line)
assert( io_transferInfo.uFilePosition % WIN32_NO_BUFFERING_BLOCK_SIZE == 0
|| !"Requested file position for I/O transfer is inconsistent with block size" );
OVERLAPPED * pOverlapped = GetFreeOverlapped( &io_transferInfo );
// Set file offset in OVERLAPPED structure.
pOverlapped->Offset = (DWORD)( io_transferInfo.uFilePosition & 0xFFFFFFFF );
pOverlapped->OffsetHigh = (DWORD)( ( io_transferInfo.uFilePosition >> 32 ) & 0xFFFFFFFF );
// File was open with asynchronous flag.
// Read overlapped.
if ( ::WriteFileEx( in_fileDesc.hFile,
io_transferInfo.pBuffer,
io_transferInfo.uRequestedSize,
pOverlapped,
CAkDefaultIOHookDeferred::FileIOCompletionRoutine ) )
{
return AK_Success;
}
return AK_Fail;
}
// Reads data from a file (asynchronous overload).
AKRESULT CAkDefaultIOHookDeferred::Read(
AkFileDesc & in_fileDesc, // File descriptor.
const AkIoHeuristics & /*in_heuristics*/, // Heuristics for this data transfer (not used in this implementation).
AkAsyncIOTransferInfo & io_transferInfo // Asynchronous data transfer info.
)
{
AKASSERT( in_fileDesc.hFile != INVALID_HANDLE_VALUE
&& io_transferInfo.uRequestedSize > 0
&& io_transferInfo.uBufferSize >= io_transferInfo.uRequestedSize );
// If this assert comes up, it might be beacause this hook's GetBlockSize() return value is incompatible
// with the system's handling of file reading for this specific file handle.
// If you are using the File Package extension, did you create your package with a compatible
// block size? It should be a multiple of WIN32_NO_BUFFERING_BLOCK_SIZE. (check -blocksize argument in the File Packager command line)
AKASSERT( ( io_transferInfo.uFilePosition % WIN32_NO_BUFFERING_BLOCK_SIZE ) == 0
|| !"Requested file position for I/O transfer is inconsistent with block size" );
OVERLAPPED * pOverlapped = GetFreeOverlapped( &io_transferInfo );
// Set file offset in OVERLAPPED structure.
pOverlapped->Offset = (DWORD)( io_transferInfo.uFilePosition & 0xFFFFFFFF );
pOverlapped->OffsetHigh = (DWORD)( ( io_transferInfo.uFilePosition >> 32 ) & 0xFFFFFFFF );
// File was open with asynchronous flag.
// Read overlapped.
// Note: With a file handle opened with FILE_FLAG_NO_BUFFERING, ::ReadFileEx() supports read sizes that go beyond the end
// of file. However, it does not support read sizes that are not a multiple of the drive's sector size.
// Since the buffer size is always a multiple of the block size, let's use io_transferInfo.uBufferSize
// instead of io_transferInfo.uRequestedSize.
if ( ::ReadFileEx( in_fileDesc.hFile,
io_transferInfo.pBuffer,
io_transferInfo.uBufferSize,
pOverlapped,
CAkDefaultIOHookDeferred::FileIOCompletionRoutine ) )
{
return AK_Success;
}
ReleaseOverlapped( pOverlapped );
return AK_Fail;
}
