github.com/Kalvelign/golang-windows-sys-lib@v0.0.0-20221121121202-63da651435e1/windows/syscall.go (about)

     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  }