vendor/golang.org/x/sys/windows/syscall.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 //go:build windows
   6 // +build windows
   7
   8 // Package windows contains an interface to the low-level operating system
   9 // primitives. OS details vary depending on the underlying system, and
  10 // by default, godoc will display the OS-specific documentation for the current
  11 // system. If you want godoc to display syscall documentation for another
  12 // system, set $GOOS and $GOARCH to the desired system. For example, if
  13 // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
  14 // to freebsd and $GOARCH to arm.
  15 //
  16 // The primary use of this package is inside other packages that provide a more
  17 // portable interface to the system, such as "os", "time" and "net".  Use
  18 // those packages rather than this one if you can.
  19 //
  20 // For details of the functions and data types in this package consult
  21 // the manuals for the appropriate operating system.
  22 //
  23 // These calls return err == nil to indicate success; otherwise
  24 // err represents an operating system error describing the failure and
  25 // holds a value of type syscall.Errno.
  26 package windows // import "golang.org/x/sys/windows"
  27
  28 import (
  29         "bytes"
  30         "strings"
  31         "syscall"
  32         "unsafe"
  33 )
  34
  35 // ByteSliceFromString returns a NUL-terminated slice of bytes
  36 // containing the text of s. If s contains a NUL byte at any
  37 // location, it returns (nil, syscall.EINVAL).
  38 func ByteSliceFromString(s string) ([]byte, error) {
  39         if strings.IndexByte(s, 0) != -1 {
  40                 return nil, syscall.EINVAL
  41         }
  42         a := make([]byte, len(s)+1)
  43         copy(a, s)
  44         return a, nil
  45 }
  46
  47 // BytePtrFromString returns a pointer to a NUL-terminated array of
  48 // bytes containing the text of s. If s contains a NUL byte at any
  49 // location, it returns (nil, syscall.EINVAL).
  50 func BytePtrFromString(s string) (*byte, error) {
  51         a, err := ByteSliceFromString(s)
  52         if err != nil {
  53                 return nil, err
  54         }
  55         return &a[0], nil
  56 }
  57
  58 // ByteSliceToString returns a string form of the text represented by the slice s, with a terminating NUL and any
  59 // bytes after the NUL removed.
  60 func ByteSliceToString(s []byte) string {
  61         if i := bytes.IndexByte(s, 0); i != -1 {
  62                 s = s[:i]
  63         }
  64         return string(s)
  65 }
  66
  67 // BytePtrToString takes a pointer to a sequence of text and returns the corresponding string.
  68 // If the pointer is nil, it returns the empty string. It assumes that the text sequence is terminated
  69 // at a zero byte; if the zero byte is not present, the program may crash.
  70 func BytePtrToString(p *byte) string {
  71         if p == nil {
  72                 return ""
  73         }
  74         if *p == 0 {
  75                 return ""
  76         }
  77
  78         // Find NUL terminator.
  79         n := 0
  80         for ptr := unsafe.Pointer(p); *(*byte)(ptr) != 0; n++ {
  81                 ptr = unsafe.Pointer(uintptr(ptr) + 1)
  82         }
  83
  84         return string(unsafe.Slice(p, n))
  85 }
  86
  87 // Single-word zero for use when we need a valid pointer to 0 bytes.
  88 // See mksyscall.pl.
  89 var _zero uintptr
  90
  91 func (ts *Timespec) Unix() (sec int64, nsec int64) {
  92         return int64(ts.Sec), int64(ts.Nsec)
  93 }
  94
  95 func (tv *Timeval) Unix() (sec int64, nsec int64) {
  96         return int64(tv.Sec), int64(tv.Usec) * 1000
  97 }
  98
  99 func (ts *Timespec) Nano() int64 {
 100         return int64(ts.Sec)*1e9 + int64(ts.Nsec)
 101 }
 102
 103 func (tv *Timeval) Nano() int64 {
 104         return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
 105 }