Function EncodeStringDescending

pkg/util/encoding/encoding.go:739–753

EncodeStringDescending is the descending version of EncodeStringAscending.

(b []byte, s string)

// EncodeStringDescending is the descending version of EncodeStringAscending.
func EncodeStringDescending(b []byte, s string) []byte {
	if len(s) == 0 {
		return EncodeBytesDescending(b, nil)
	}
	// We unsafely convert the string to a []byte to avoid the
	// usual allocation when converting to a []byte. This is
	// kosher because we know that EncodeBytes{,Descending} does
	// not keep a reference to the value it encodes. The first
	// step is getting access to the string internals.
	hdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
	// Next we treat the string data as a maximally sized array which we
	// slice. This usage is safe because the pointer value remains in the string.
	arg := (*[0x7fffffff]byte)(unsafe.Pointer(hdr.Data))[:len(s):len(s)]
	return EncodeBytesDescending(b, arg)
}

// unsafeString performs an unsafe conversion from a []byte to a string. The
// returned string will share the underlying memory with the []byte which thus