Files
wazero/internal/sysfs/file_windows.go
Crypt Keeper 66070781b1 Supports compilation with GOOS=plan9 (#1603)
Signed-off-by: Adrian Cole <adrian@tetrate.io>
2023-07-31 06:47:23 +08:00

89 lines
2.7 KiB
Go

package sysfs
import (
"syscall"
"unsafe"
"github.com/tetratelabs/wazero/experimental/sys"
)
const (
nonBlockingFileReadSupported = true
nonBlockingFileWriteSupported = false
)
var kernel32 = syscall.NewLazyDLL("kernel32.dll")
// procPeekNamedPipe is the syscall.LazyProc in kernel32 for PeekNamedPipe
var procPeekNamedPipe = kernel32.NewProc("PeekNamedPipe")
// readFd returns ENOSYS on unsupported platforms.
//
// PeekNamedPipe: https://learn.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-peeknamedpipe
// "GetFileType can assist in determining what device type the handle refers to. A console handle presents as FILE_TYPE_CHAR."
// https://learn.microsoft.com/en-us/windows/console/console-handles
func readFd(fd uintptr, buf []byte) (int, sys.Errno) {
handle := syscall.Handle(fd)
fileType, err := syscall.GetFileType(handle)
if err != nil {
return 0, sys.UnwrapOSError(err)
}
if fileType&syscall.FILE_TYPE_CHAR == 0 {
return -1, sys.ENOSYS
}
n, errno := peekNamedPipe(handle)
if errno == syscall.ERROR_BROKEN_PIPE {
return 0, 0
}
if n == 0 {
return -1, sys.EAGAIN
}
un, err := syscall.Read(handle, buf[0:n])
return un, sys.UnwrapOSError(err)
}
func writeFd(fd uintptr, buf []byte) (int, sys.Errno) {
return -1, sys.ENOSYS
}
func readSocket(h syscall.Handle, buf []byte) (int, sys.Errno) {
var overlapped syscall.Overlapped
var done uint32
errno := syscall.ReadFile(h, buf, &done, &overlapped)
if errno == syscall.ERROR_IO_PENDING {
errno = sys.EAGAIN
}
return int(done), sys.UnwrapOSError(errno)
}
func writeSocket(fd uintptr, buf []byte) (int, sys.Errno) {
var done uint32
var overlapped syscall.Overlapped
errno := syscall.WriteFile(syscall.Handle(fd), buf, &done, &overlapped)
if errno == syscall.ERROR_IO_PENDING {
errno = syscall.EAGAIN
}
return int(done), sys.UnwrapOSError(errno)
}
// peekNamedPipe partially exposes PeekNamedPipe from the Win32 API
// see https://learn.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-peeknamedpipe
func peekNamedPipe(handle syscall.Handle) (uint32, syscall.Errno) {
var totalBytesAvail uint32
totalBytesPtr := unsafe.Pointer(&totalBytesAvail)
_, _, errno := syscall.SyscallN(
procPeekNamedPipe.Addr(),
uintptr(handle), // [in] HANDLE hNamedPipe,
0, // [out, optional] LPVOID lpBuffer,
0, // [in] DWORD nBufferSize,
0, // [out, optional] LPDWORD lpBytesRead
uintptr(totalBytesPtr), // [out, optional] LPDWORD lpTotalBytesAvail,
0) // [out, optional] LPDWORD lpBytesLeftThisMessage
return totalBytesAvail, errno
}
func rmdir(path string) sys.Errno {
err := syscall.Rmdir(path)
return sys.UnwrapOSError(err)
}