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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
#![unstable(reason = "not public", issue = "0", feature = "fd")]
use cmp;
use io::{self, Read};
use libc::{self, c_int, c_void, ssize_t};
use mem;
use sync::atomic::{AtomicBool, Ordering};
use sys::cvt;
use sys_common::AsInner;
#[derive(Debug)]
pub struct FileDesc {
fd: c_int,
}
fn max_len() -> usize {
if cfg!(target_os = "macos") {
<c_int>::max_value() as usize - 1
} else {
<ssize_t>::max_value() as usize
}
}
impl FileDesc {
pub fn new(fd: c_int) -> FileDesc {
FileDesc { fd: fd }
}
pub fn raw(&self) -> c_int { self.fd }
pub fn into_raw(self) -> c_int {
let fd = self.fd;
mem::forget(self);
fd
}
pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::read(self.fd,
buf.as_mut_ptr() as *mut c_void,
cmp::min(buf.len(), max_len()))
})?;
Ok(ret as usize)
}
pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
let mut me = self;
(&mut me).read_to_end(buf)
}
pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
#[cfg(target_os = "android")]
use super::android::cvt_pread64;
#[cfg(target_os = "emscripten")]
unsafe fn cvt_pread64(fd: c_int, buf: *mut c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use libc::pread64;
cvt(pread64(fd, buf, count, offset as i32))
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]
unsafe fn cvt_pread64(fd: c_int, buf: *mut c_void, count: usize, offset: i64)
-> io::Result<isize>
{
#[cfg(target_os = "linux")]
use libc::pread64;
#[cfg(not(target_os = "linux"))]
use libc::pread as pread64;
cvt(pread64(fd, buf, count, offset))
}
unsafe {
cvt_pread64(self.fd,
buf.as_mut_ptr() as *mut c_void,
cmp::min(buf.len(), max_len()),
offset as i64)
.map(|n| n as usize)
}
}
pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::write(self.fd,
buf.as_ptr() as *const c_void,
cmp::min(buf.len(), max_len()))
})?;
Ok(ret as usize)
}
pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
#[cfg(target_os = "android")]
use super::android::cvt_pwrite64;
#[cfg(target_os = "emscripten")]
unsafe fn cvt_pwrite64(fd: c_int, buf: *const c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use libc::pwrite64;
cvt(pwrite64(fd, buf, count, offset as i32))
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]
unsafe fn cvt_pwrite64(fd: c_int, buf: *const c_void, count: usize, offset: i64)
-> io::Result<isize>
{
#[cfg(target_os = "linux")]
use libc::pwrite64;
#[cfg(not(target_os = "linux"))]
use libc::pwrite as pwrite64;
cvt(pwrite64(fd, buf, count, offset))
}
unsafe {
cvt_pwrite64(self.fd,
buf.as_ptr() as *const c_void,
cmp::min(buf.len(), max_len()),
offset as i64)
.map(|n| n as usize)
}
}
#[cfg(not(any(target_env = "newlib",
target_os = "solaris",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "haiku")))]
pub fn set_cloexec(&self) -> io::Result<()> {
unsafe {
cvt(libc::ioctl(self.fd, libc::FIOCLEX))?;
Ok(())
}
}
#[cfg(any(target_env = "newlib",
target_os = "solaris",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "haiku"))]
pub fn set_cloexec(&self) -> io::Result<()> {
unsafe {
let previous = cvt(libc::fcntl(self.fd, libc::F_GETFD))?;
let new = previous | libc::FD_CLOEXEC;
if new != previous {
cvt(libc::fcntl(self.fd, libc::F_SETFD, new))?;
}
Ok(())
}
}
#[cfg(target_os = "linux")]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let v = nonblocking as c_int;
cvt(libc::ioctl(self.fd, libc::FIONBIO, &v))?;
Ok(())
}
}
#[cfg(not(target_os = "linux"))]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let previous = cvt(libc::fcntl(self.fd, libc::F_GETFL))?;
let new = if nonblocking {
previous | libc::O_NONBLOCK
} else {
previous & !libc::O_NONBLOCK
};
if new != previous {
cvt(libc::fcntl(self.fd, libc::F_SETFL, new))?;
}
Ok(())
}
}
pub fn duplicate(&self) -> io::Result<FileDesc> {
#[cfg(any(target_os = "android", target_os = "haiku"))]
use libc::F_DUPFD as F_DUPFD_CLOEXEC;
#[cfg(not(any(target_os = "android", target_os="haiku")))]
use libc::F_DUPFD_CLOEXEC;
let make_filedesc = |fd| {
let fd = FileDesc::new(fd);
fd.set_cloexec()?;
Ok(fd)
};
static TRY_CLOEXEC: AtomicBool =
AtomicBool::new(!cfg!(target_os = "android"));
let fd = self.raw();
if TRY_CLOEXEC.load(Ordering::Relaxed) {
match cvt(unsafe { libc::fcntl(fd, F_DUPFD_CLOEXEC, 0) }) {
Ok(fd) => {
return Ok(if cfg!(target_os = "linux") {
make_filedesc(fd)?
} else {
FileDesc::new(fd)
})
}
Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {
TRY_CLOEXEC.store(false, Ordering::Relaxed);
}
Err(e) => return Err(e),
}
}
cvt(unsafe { libc::fcntl(fd, libc::F_DUPFD, 0) }).and_then(make_filedesc)
}
}
impl<'a> Read for &'a FileDesc {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
}
impl AsInner<c_int> for FileDesc {
fn as_inner(&self) -> &c_int { &self.fd }
}
impl Drop for FileDesc {
fn drop(&mut self) {
let _ = unsafe { libc::close(self.fd) };
}
}