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use std::ffi::CStr;
use std::fmt;
use std::os::raw::{c_char, c_void};
use std::str;
use malloc_buf::MallocBuffer;
use runtime::{Class, Object, Sel};
const QUALIFIERS: &'static [char] = &[
'r', // const
'n', // in
'N', // inout
'o', // out
'O', // bycopy
'R', // byref
'V', // oneway
];
#[cfg(target_pointer_width = "64")]
const CODE_INLINE_CAP: usize = 30;
#[cfg(target_pointer_width = "32")]
const CODE_INLINE_CAP: usize = 14;
enum Code {
Slice(&'static str),
Owned(String),
Inline(u8, [u8; CODE_INLINE_CAP]),
Malloc(MallocBuffer<u8>)
}
/// An Objective-C type encoding.
///
/// For more information, see Apple's documentation:
pub struct Encoding {
code: Code,
}
impl Encoding {
/// Constructs an `Encoding` from its string representation.
/// Unsafe because the caller must ensure the string is a valid encoding.
pub unsafe fn from_str(code: &str) -> Encoding {
from_str(code)
}
/// Returns self as a `str`.
pub fn as_str(&self) -> &str {
match self.code {
Code::Slice(code) => code,
Code::Owned(ref code) => code,
Code::Inline(len, ref bytes) => unsafe {
str::from_utf8_unchecked(&bytes[..len as usize])
},
Code::Malloc(ref buf) => unsafe {
str::from_utf8_unchecked(&buf[..buf.len() - 1])
},
}
}
}
impl Clone for Encoding {
fn clone(&self) -> Encoding {
if let Code::Slice(code) = self.code {
from_static_str(code)
} else {
from_str(self.as_str())
}
}
}
impl PartialEq for Encoding {
fn eq(&self, other: &Encoding) -> bool {
// strip qualifiers when comparing
let s = self.as_str().trim_left_matches(QUALIFIERS);
let o = other.as_str().trim_left_matches(QUALIFIERS);
s == o
}
}
impl fmt::Debug for Encoding {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.as_str())
}
}
pub fn from_static_str(code: &'static str) -> Encoding {
Encoding { code: Code::Slice(code) }
}
pub fn from_str(code: &str) -> Encoding {
if code.len() > CODE_INLINE_CAP {
Encoding { code: Code::Owned(code.to_owned()) }
} else {
let mut bytes = [0; CODE_INLINE_CAP];
for (dst, byte) in bytes.iter_mut().zip(code.bytes()) {
*dst = byte;
}
Encoding { code: Code::Inline(code.len() as u8, bytes) }
}
}
pub unsafe fn from_malloc_str(ptr: *mut c_char) -> Encoding {
let s = CStr::from_ptr(ptr);
let bytes = s.to_bytes_with_nul();
assert!(str::from_utf8(bytes).is_ok());
let buf = MallocBuffer::new(ptr as *mut u8, bytes.len()).unwrap();
Encoding { code: Code::Malloc(buf) }
}
/// Types that have an Objective-C type encoding.
///
/// Unsafe because Objective-C will make assumptions about the type (like its
/// size and alignment) from its encoding, so the implementer must verify that
/// the encoding is accurate.
pub unsafe trait Encode {
/// Returns the Objective-C type encoding for Self.
fn encode() -> Encoding;
}
macro_rules! encode_impls {
($($t:ty : $s:expr,)*) => ($(
unsafe impl Encode for $t {
fn encode() -> Encoding { from_static_str($s) }
}
)*);
}
encode_impls!(
i8: "c",
i16: "s",
i32: "i",
i64: "q",
u8: "C",
u16: "S",
u32: "I",
u64: "Q",
f32: "f",
f64: "d",
bool: "B",
(): "v",
*mut c_char: "*",
*const c_char: "r*",
*mut c_void: "^v",
*const c_void: "r^v",
Sel: ":",
);
unsafe impl Encode for isize {
#[cfg(target_pointer_width = "32")]
fn encode() -> Encoding { i32::encode() }
#[cfg(target_pointer_width = "64")]
fn encode() -> Encoding { i64::encode() }
}
unsafe impl Encode for usize {
#[cfg(target_pointer_width = "32")]
fn encode() -> Encoding { u32::encode() }
#[cfg(target_pointer_width = "64")]
fn encode() -> Encoding { u64::encode() }
}
macro_rules! encode_message_impl {
($code:expr, $name:ident) => (
encode_message_impl!($code, $name,);
);
($code:expr, $name:ident, $($t:ident),*) => (
unsafe impl<'a $(, $t)*> $crate::Encode for &'a $name<$($t),*> {
fn encode() -> Encoding { from_static_str($code) }
}
unsafe impl<'a $(, $t)*> $crate::Encode for &'a mut $name<$($t),*> {
fn encode() -> Encoding { from_static_str($code) }
}
unsafe impl<'a $(, $t)*> $crate::Encode for Option<&'a $name<$($t),*>> {
fn encode() -> Encoding { from_static_str($code) }
}
unsafe impl<'a $(, $t)*> $crate::Encode for Option<&'a mut $name<$($t),*>> {
fn encode() -> Encoding { from_static_str($code) }
}
unsafe impl<$($t),*> $crate::Encode for *const $name<$($t),*> {
fn encode() -> Encoding { from_static_str($code) }
}
unsafe impl<$($t),*> $crate::Encode for *mut $name<$($t),*> {
fn encode() -> Encoding { from_static_str($code) }
}
);
}
encode_message_impl!("@", Object);
encode_message_impl!("#", Class);
/// Types that represent a group of arguments, where each has an Objective-C
/// type encoding.
pub trait EncodeArguments {
/// The type as which the encodings for Self will be returned.
type Encs: AsRef<[Encoding]>;
/// Returns the Objective-C type encodings for Self.
fn encodings() -> Self::Encs;
}
macro_rules! count_idents {
() => (0);
($a:ident) => (1);
($a:ident, $($b:ident),+) => (1 + count_idents!($($b),*));
}
macro_rules! encode_args_impl {
($($t:ident),*) => (
impl<$($t: Encode),*> EncodeArguments for ($($t,)*) {
type Encs = [Encoding; count_idents!($($t),*)];
fn encodings() -> Self::Encs {
[
$($t::encode()),*
]
}
}
);
}
encode_args_impl!();
encode_args_impl!(A);
encode_args_impl!(A, B);
encode_args_impl!(A, B, C);
encode_args_impl!(A, B, C, D);
encode_args_impl!(A, B, C, D, E);
encode_args_impl!(A, B, C, D, E, F);
encode_args_impl!(A, B, C, D, E, F, G);
encode_args_impl!(A, B, C, D, E, F, G, H);
encode_args_impl!(A, B, C, D, E, F, G, H, I);
encode_args_impl!(A, B, C, D, E, F, G, H, I, J);
encode_args_impl!(A, B, C, D, E, F, G, H, I, J, K);
encode_args_impl!(A, B, C, D, E, F, G, H, I, J, K, L);
#[cfg(test)]
mod tests {
use runtime::{Class, Object, Sel};
use super::{Encode, Encoding};
#[test]
fn test_encode() {
assert!(u32::encode().as_str() == "I");
assert!(<()>::encode().as_str() == "v");
assert!(<&Object>::encode().as_str() == "@");
assert!(<*mut Object>::encode().as_str() == "@");
assert!(<&Class>::encode().as_str() == "#");
assert!(Sel::encode().as_str() == ":");
}
#[test]
fn test_inline_encoding() {
let enc = unsafe { Encoding::from_str("C") };
assert!(enc.as_str() == "C");
let enc2 = enc.clone();
assert!(enc2 == enc);
assert!(enc2.as_str() == "C");
}
#[test]
fn test_owned_encoding() {
let s = "{Test=CCCCCCCCCCCCCCCCCCCCCCCCC}";
let enc = unsafe { Encoding::from_str(s) };
assert!(enc.as_str() == s);
let enc2 = enc.clone();
assert!(enc2 == enc);
assert!(enc2.as_str() == s);
}
}