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
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
use super::{sys, CoreType};
use std::borrow::Cow;
use std::ffi::{CStr, CString};
use std::ptr;
use std::ptr::NonNull;
pub trait StrLike {
fn encoding(&self) -> sys::CFStringEncoding;
fn len(&self) -> usize;
fn as_ptr(&self) -> *const u8;
}
impl StrLike for str {
fn encoding(&self) -> sys::CFStringEncoding {
sys::kCFStringEncodingUTF8
}
fn len(&self) -> usize {
self.len()
}
fn as_ptr(&self) -> *const u8 {
self.as_ptr()
}
}
impl StrLike for CStr {
fn encoding(&self) -> sys::CFStringEncoding {
if self.to_str().is_ok() {
sys::kCFStringEncodingUTF8
} else {
sys::kCFStringEncodingASCII
}
}
fn len(&self) -> usize {
self.to_bytes().len()
}
fn as_ptr(&self) -> *const u8 {
self.as_ptr().cast()
}
}
cfty! {
/// A string. Note this is not necessarily like [`String`], as the contained bytes may not
/// be in UTF-8.
CFString : CFStringGetTypeID
}
impl CFString {
/// Create a new string from a value. The value may be any of multiple Rust string types, such
/// as `str` or `CStr`.
pub fn new<S: ?Sized + StrLike>(val: &S) -> CFString {
// SAFETY: Length, pointer, and encoding are derived from same value.
let ptr = unsafe {
sys::CFStringCreateWithBytes(
ptr::null(),
val.as_ptr(),
val.len() as sys::CFIndex,
val.encoding(),
false,
)
};
let ptr = NonNull::new(ptr.cast_mut()).unwrap();
// SAFETY: If non-null, pointer returned by CFStringCreateWithBytes is guaranteed to be a
// valid CFString.
unsafe { CFString::new_owned(ptr) }
}
/// Get the length of this string
pub fn len(&self) -> usize {
// SAFETY: Self is guaranteed to be valid
unsafe { sys::CFStringGetLength(self.as_type_ref()) as usize }
}
/// Check whether this string is empty (has a length of 0)
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Get this value as a Rust [`String`]. The value will be re-encoded into UTF-8 if in another
/// encoding.
pub fn get_string(&self) -> String {
let mut buf_len = 0;
// SAFETY: Self is guaranteed valid. No buffer is passed.
unsafe {
sys::CFStringGetBytes(
self.as_type_ref(),
sys::CFRange {
location: 0,
length: self.len() as sys::CFIndex,
},
sys::kCFStringEncodingUTF8,
0,
false,
ptr::null_mut(),
0,
&mut buf_len,
)
};
let mut buf = vec![0u8; buf_len as usize];
// SAFETY: Self is guaranteed valid. Buffer is allocated to the correct length.
let written = unsafe {
sys::CFStringGetBytes(
self.as_type_ref(),
sys::CFRange {
location: 0,
length: self.len() as sys::CFIndex,
},
sys::kCFStringEncodingUTF8,
0,
false,
buf.as_mut_ptr(),
buf_len,
&mut buf_len,
)
};
if written as usize == self.len() {
String::from_utf8(buf).unwrap()
} else {
panic!("Failed to convert CFString");
}
}
/// Attempt to get a reference to this value as a `str`, if the value is natively UTF-8,
/// otherwise re-encode into UTF-8.
pub fn as_str(&self) -> Cow<'_, str> {
// SAFETY: Self is guaranteed valid
let cstr =
unsafe { sys::CFStringGetCStringPtr(self.as_type_ref(), sys::kCFStringEncodingUTF8) };
if cstr.is_null() {
Cow::Owned(self.get_string())
} else {
// SAFETY: If non-null, the return value of CFStringGetCStringPtr is guaranteed to be a
// valid C-string
Cow::Borrowed(unsafe { CStr::from_ptr(cstr) }.to_str().unwrap())
}
}
/// Get this value as a null-terminated C-string
pub fn get_cstring(&self) -> Option<CString> {
let len = self.len() * 4 + 1;
let mut buf = vec![0; len];
// SAFETY: Self is guaranteed valid. Buffer is definitely of sufficient length to hold the
// bytes of self.
let res = unsafe {
sys::CFStringGetCString(
self.as_type_ref(),
buf.as_mut_ptr().cast(),
len as sys::CFIndex,
sys::kCFStringEncodingUTF8,
)
};
if res {
let buf = buf.into_iter().take_while(|&c| c != 0).collect::<Vec<_>>();
if buf.len() != self.len() {
None
} else {
Some(CString::new(buf).unwrap())
}
} else {
None
}
}
/// Attempt to get a reference to this value as a `CStr`, if the value is natively UTF-8,
/// otherwise allocate a CString in that encoding.
pub fn as_cstr(&self) -> Option<Cow<'_, CStr>> {
// SAFETY: Self is guaranteed valid
let cstr =
unsafe { sys::CFStringGetCStringPtr(self.as_type_ref(), sys::kCFStringEncodingUTF8) };
if cstr.is_null() {
self.get_cstring().map(Cow::Owned)
} else {
// SAFETY: If non-null, the return value of CFStringGetCStringPtr is guaranteed to be a
// valid C-string
Some(Cow::Borrowed(unsafe { CStr::from_ptr(cstr) }))
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_as_str() {
let str = CFString::new("foo");
assert_eq!(str.as_str(), Cow::Borrowed("foo"));
let cstr = CFString::new(c"foo");
assert_eq!(cstr.as_str(), Cow::Borrowed("foo"));
// Invalid UTF-8 CStrings are treated as extended-ASCII.
let non_str = CFString::new(c"\xC3\x28bar");
assert_eq!(non_str.as_str(), Cow::<str>::Owned("Ã(bar".to_string()));
}
#[test]
fn test_as_cstr() {
let str = CFString::new("foo");
assert_eq!(str.as_cstr(), Some(Cow::<CStr>::Owned(c"foo".to_owned())));
let cstr = CFString::new(c"foo");
assert_eq!(cstr.as_cstr(), Some(Cow::Borrowed(c"foo")));
}
#[test]
fn test_as_non_cstr() {
let non_cstr = CFString::new("fo\0o");
assert!(non_cstr.as_cstr().is_none());
}
}