void set_low_priority(file_handle const& f)
{
// file prio is only supported on vista and up
// so load the functions dynamically
typedef enum {
FileBasicInfo,
FileStandardInfo,
FileNameInfo,
FileRenameInfo,
FileDispositionInfo,
FileAllocationInfo,
FileEndOfFileInfo,
FileStreamInfo,
FileCompressionInfo,
FileAttributeTagInfo,
FileIdBothDirectoryInfo,
FileIdBothDirectoryRestartInfo,
FileIoPriorityHintInfo,
FileRemoteProtocolInfo,
MaximumFileInfoByHandleClass
} FILE_INFO_BY_HANDLE_CLASS_LOCAL;
typedef enum {
IoPriorityHintVeryLow = 0,
IoPriorityHintLow,
IoPriorityHintNormal,
MaximumIoPriorityHintType
} PRIORITY_HINT_LOCAL;
typedef struct {
PRIORITY_HINT_LOCAL PriorityHint;
} FILE_IO_PRIORITY_HINT_INFO_LOCAL;
typedef BOOL (WINAPI *SetFileInformationByHandle_t)(HANDLE hFile, FILE_INFO_BY_HANDLE_CLASS_LOCAL FileInformationClass, LPVOID lpFileInformation, DWORD dwBufferSize);
auto SetFileInformationByHandle =
aux::get_library_procedure<aux::kernel32, SetFileInformationByHandle_t>("SetFileInformationByHandle");
if (SetFileInformationByHandle == nullptr) return;
FILE_IO_PRIORITY_HINT_INFO_LOCAL io_hint;
io_hint.PriorityHint = IoPriorityHintLow;
SetFileInformationByHandle(f->native_handle(),
FileIoPriorityHintInfo, &io_hint, sizeof(io_hint));
}
void set_low_priority(file_handle const& f)
{
// file prio is only supported on vista and up
// so load the functions dynamically
typedef enum _FILE_INFO_BY_HANDLE_CLASS {
FileBasicInfo,
FileStandardInfo,
FileNameInfo,
FileRenameInfo,
FileDispositionInfo,
FileAllocationInfo,
FileEndOfFileInfo,
FileStreamInfo,
FileCompressionInfo,
FileAttributeTagInfo,
FileIdBothDirectoryInfo,
FileIdBothDirectoryRestartInfo,
FileIoPriorityHintInfo,
FileRemoteProtocolInfo,
MaximumFileInfoByHandleClass
} FILE_INFO_BY_HANDLE_CLASS, *PFILE_INFO_BY_HANDLE_CLASS;
typedef enum _PRIORITY_HINT {
IoPriorityHintVeryLow = 0,
IoPriorityHintLow,
IoPriorityHintNormal,
MaximumIoPriorityHintType
} PRIORITY_HINT;
typedef struct _FILE_IO_PRIORITY_HINT_INFO {
PRIORITY_HINT PriorityHint;
} FILE_IO_PRIORITY_HINT_INFO, *PFILE_IO_PRIORITY_HINT_INFO;
typedef BOOL (WINAPI *SetFileInformationByHandle_t)(HANDLE hFile, FILE_INFO_BY_HANDLE_CLASS FileInformationClass, LPVOID lpFileInformation, DWORD dwBufferSize);
static SetFileInformationByHandle_t SetFileInformationByHandle = NULL;
static bool failed_kernel_load = false;
if (failed_kernel_load) return;
if (SetFileInformationByHandle == NULL)
{
HMODULE kernel32 = LoadLibraryA("kernel32.dll");
if (kernel32 == NULL)
{
failed_kernel_load = true;
return;
}
SetFileInformationByHandle = (SetFileInformationByHandle_t)GetProcAddress(kernel32, "SetFileInformationByHandle");
if (SetFileInformationByHandle == NULL)
{
failed_kernel_load = true;
return;
}
}
TORRENT_ASSERT(SetFileInformationByHandle);
FILE_IO_PRIORITY_HINT_INFO io_hint;
io_hint.PriorityHint = IoPriorityHintLow;
SetFileInformationByHandle(f->native_handle(),
FileIoPriorityHintInfo, &io_hint, sizeof(io_hint));
}
