1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
//go:build purego || !amd64
// +build purego !amd64
package ascii
import "unsafe"
// ValidString returns true if s contains only printable ASCII characters.
func ValidPrintString(s string) bool {
p := *(*unsafe.Pointer)(unsafe.Pointer(&s))
i := uintptr(0)
n := uintptr(len(s))
for i+8 <= n {
if hasLess64(*(*uint64)(unsafe.Pointer(uintptr(p) + i)), 0x20) || hasMore64(*(*uint64)(unsafe.Pointer(uintptr(p) + i)), 0x7e) {
return false
}
i += 8
}
if i+4 <= n {
if hasLess32(*(*uint32)(unsafe.Pointer(uintptr(p) + i)), 0x20) || hasMore32(*(*uint32)(unsafe.Pointer(uintptr(p) + i)), 0x7e) {
return false
}
i += 4
}
if i == n {
return true
}
p = unsafe.Pointer(uintptr(p) + i)
var x uint32
switch n - i {
case 3:
x = 0x20000000 | uint32(*(*uint16)(p)) | uint32(*(*uint8)(unsafe.Pointer(uintptr(p) + 2)))<<16
case 2:
x = 0x20200000 | uint32(*(*uint16)(p))
case 1:
x = 0x20202000 | uint32(*(*uint8)(p))
default:
return true
}
return !(hasLess32(x, 0x20) || hasMore32(x, 0x7e))
}
|
