miow 0.3.3

A zero overhead I/O library for Windows, focusing on IOCP and Async I/O abstractions.
Documentation 
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

use std::io;
use std::cmp;
use std::ptr;

use winapi::shared::minwindef::*;
use winapi::shared::ntdef::{
    BOOLEAN,
    FALSE,
    HANDLE,
    TRUE,
};
use winapi::shared::winerror::*;
use winapi::um::fileapi::*;
use winapi::um::handleapi::*;
use winapi::um::ioapiset::*;
use winapi::um::minwinbase::*;

#[derive(Debug)]
pub struct Handle(HANDLE);

unsafe impl Send for Handle {}
unsafe impl Sync for Handle {}

impl Handle {
    pub fn new(handle: HANDLE) -> Handle {
        Handle(handle)
    }

    pub fn raw(&self) -> HANDLE { self.0 }

    pub fn into_raw(self) -> HANDLE {
        use std::mem;

        let ret = self.0;
        mem::forget(self);
        ret
    }

    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
        let mut bytes = 0;
        let len = cmp::min(buf.len(), <DWORD>::max_value() as usize) as DWORD;
        try!(::cvt(unsafe {
            WriteFile(self.0, buf.as_ptr() as *const _, len, &mut bytes,
                      0 as *mut _)
        }));
        Ok(bytes as usize)
    }

    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
        let mut bytes = 0;
        let len = cmp::min(buf.len(), <DWORD>::max_value() as usize) as DWORD;
        try!(::cvt(unsafe {
            ReadFile(self.0, buf.as_mut_ptr() as *mut _, len, &mut bytes,
                     0 as *mut _)
        }));
        Ok(bytes as usize)
    }

    pub unsafe fn read_overlapped(&self, buf: &mut [u8],
                                   overlapped: *mut OVERLAPPED)
                                   -> io::Result<Option<usize>> {
        self.read_overlapped_helper(buf, overlapped, FALSE)
    }

    pub unsafe fn read_overlapped_wait(&self, buf: &mut [u8],
                                        overlapped: *mut OVERLAPPED)
                                        -> io::Result<usize> {
        match self.read_overlapped_helper(buf, overlapped, TRUE) {
            Ok(Some(bytes)) => Ok(bytes),
            Ok(None) => panic!("logic error"),
            Err(e) => Err(e),
        }
    }

    pub unsafe fn read_overlapped_helper(&self, buf: &mut [u8],
                                            overlapped: *mut OVERLAPPED,
                                            wait: BOOLEAN)
                                            -> io::Result<Option<usize>> {
        let len = cmp::min(buf.len(), <DWORD>::max_value() as usize) as DWORD;
        let res = ::cvt({
            ReadFile(self.0,
                     buf.as_mut_ptr() as *mut _,
                     len,
                     ptr::null_mut(),
                     overlapped)
        });
        match res {
            Ok(_) => (),
            Err(ref e) if e.raw_os_error() == Some(ERROR_IO_PENDING as i32)
                => (),
            Err(e) => return Err(e),
        }

        let mut bytes = 0;
        let res = ::cvt({
            GetOverlappedResult(self.0,
                                overlapped,
                                &mut bytes,
                                wait as BOOL)
        });
        match res {
            Ok(_) => Ok(Some(bytes as usize)),
            Err(ref e) if e.raw_os_error() == Some(ERROR_IO_INCOMPLETE as i32) && wait == FALSE
                => Ok(None),
            Err(e) => Err(e),
        }
    }

    pub unsafe fn write_overlapped(&self, buf: &[u8],
                                   overlapped: *mut OVERLAPPED)
                                   -> io::Result<Option<usize>> {
        self.write_overlapped_helper(buf, overlapped, FALSE)
    }

    pub unsafe fn write_overlapped_wait(&self, buf: &[u8],
                                        overlapped: *mut OVERLAPPED)
                                        -> io::Result<usize> {
        match self.write_overlapped_helper(buf, overlapped, TRUE) {
            Ok(Some(bytes)) => Ok(bytes),
            Ok(None) => panic!("logic error"),
            Err(e) => Err(e),
        }
    }

    unsafe fn write_overlapped_helper(&self, buf: &[u8],
                                        overlapped: *mut OVERLAPPED,
                                        wait: BOOLEAN)
                                        -> io::Result<Option<usize>> {
        let len = cmp::min(buf.len(), <DWORD>::max_value() as usize) as DWORD;
        let res = ::cvt({
            WriteFile(self.0,
                      buf.as_ptr() as *const _,
                      len,
                      ptr::null_mut(),
                      overlapped)
        });
        match res {
            Ok(_) => (),
            Err(ref e) if e.raw_os_error() == Some(ERROR_IO_PENDING as i32)
                => (),
            Err(e) => return Err(e),
        }

        let mut bytes = 0;
        let res = ::cvt({
            GetOverlappedResult(self.0,
                                overlapped,
                                &mut bytes,
                                wait as BOOL)
        });
        match res {
            Ok(_) => Ok(Some(bytes as usize)),
            Err(ref e) if e.raw_os_error() == Some(ERROR_IO_INCOMPLETE as i32) && wait == FALSE
                => Ok(None),
            Err(e) => Err(e),
        }
    }
}

impl Drop for Handle {
    fn drop(&mut self) {
        unsafe { CloseHandle(self.0) };
    }
}