alsa/
rawmidi.rs

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1//! MIDI devices I/O and enumeration
2
3use libc::{c_int, c_uint, c_void, size_t, c_short, pollfd};
4use super::ctl_int::{ctl_ptr, Ctl};
5use super::{Direction, poll};
6use super::error::*;
7use crate::alsa;
8use std::{ptr, io};
9use std::ffi::{CStr, CString};
10
11/// Iterator over [Rawmidi](http://www.alsa-project.org/alsa-doc/alsa-lib/group___raw_midi.html) devices and subdevices
12pub struct Iter<'a> {
13    ctl: &'a Ctl,
14    device: c_int,
15    in_count: i32,
16    out_count: i32,
17    current: i32,
18}
19
20/// [snd_rawmidi_info_t](http://www.alsa-project.org/alsa-doc/alsa-lib/group___raw_midi.html) wrapper
21pub struct Info(*mut alsa::snd_rawmidi_info_t);
22
23impl Drop for Info {
24    fn drop(&mut self) { unsafe { alsa::snd_rawmidi_info_free(self.0) }; }
25}
26
27impl Info {
28    fn new() -> Result<Info> {
29        let mut p = ptr::null_mut();
30        acheck!(snd_rawmidi_info_malloc(&mut p)).map(|_| Info(p))
31    }
32
33    fn from_iter(c: &Ctl, device: i32, sub: i32, dir: Direction) -> Result<Info> {
34        let r = Info::new()?;
35        unsafe { alsa::snd_rawmidi_info_set_device(r.0, device as c_uint) };
36        let d = match dir {
37            Direction::Playback => alsa::SND_RAWMIDI_STREAM_OUTPUT,
38            Direction::Capture => alsa::SND_RAWMIDI_STREAM_INPUT,
39        };
40        unsafe { alsa::snd_rawmidi_info_set_stream(r.0, d) };
41        unsafe { alsa::snd_rawmidi_info_set_subdevice(r.0, sub as c_uint) };
42        acheck!(snd_ctl_rawmidi_info(ctl_ptr(c), r.0)).map(|_| r)
43    }
44
45    fn subdev_count(c: &Ctl, device: c_int) -> Result<(i32, i32)> {
46        let i = Info::from_iter(c, device, 0, Direction::Capture)?;
47        let o = Info::from_iter(c, device, 0, Direction::Playback)?;
48        Ok((unsafe { alsa::snd_rawmidi_info_get_subdevices_count(o.0) as i32 },
49            unsafe { alsa::snd_rawmidi_info_get_subdevices_count(i.0) as i32 }))
50    }
51
52    pub fn get_device(&self) -> i32 { unsafe { alsa::snd_rawmidi_info_get_device(self.0) as i32 }}
53    pub fn get_subdevice(&self) -> i32 { unsafe { alsa::snd_rawmidi_info_get_subdevice(self.0) as i32 }}
54    pub fn get_stream(&self) -> super::Direction {
55        if unsafe { alsa::snd_rawmidi_info_get_stream(self.0) } == alsa::SND_RAWMIDI_STREAM_OUTPUT { super::Direction::Playback }
56        else { super::Direction::Capture }
57    }
58
59    pub fn get_subdevice_name(&self) -> Result<String> {
60        let c = unsafe { alsa::snd_rawmidi_info_get_subdevice_name(self.0) };
61        from_const("snd_rawmidi_info_get_subdevice_name", c).map(|s| s.to_string())
62    }
63    pub fn get_id(&self) -> Result<String> {
64        let c = unsafe { alsa::snd_rawmidi_info_get_id(self.0) };
65        from_const("snd_rawmidi_info_get_id", c).map(|s| s.to_string())
66    }
67}
68
69/// [snd_rawmidi_info_t](http://www.alsa-project.org/alsa-doc/alsa-lib/group___raw_midi.html) wrapper
70pub struct Status(*mut alsa::snd_rawmidi_status_t);
71
72impl Status {
73    fn new() -> Result<Self> {
74        let mut p = ptr::null_mut();
75        acheck!(snd_rawmidi_status_malloc(&mut p)).map(|_| Status(p))
76    }
77}
78
79impl Status {
80    pub fn get_avail(&self) -> usize { unsafe { alsa::snd_rawmidi_status_get_avail(self.0 as *const _) } }
81    pub fn get_xruns(&self) -> usize { unsafe { alsa::snd_rawmidi_status_get_xruns(self.0 as *const _) } }
82}
83
84impl Drop for Status {
85    fn drop(&mut self) { unsafe { alsa::snd_rawmidi_status_free(self.0) }; }
86}
87
88
89impl<'a> Iter<'a> {
90    pub fn new(c: &'a Ctl) -> Iter<'a> { Iter { ctl: c, device: -1, in_count: 0, out_count: 0, current: 0 }}
91}
92
93impl<'a> Iterator for Iter<'a> {
94    type Item = Result<Info>;
95    fn next(&mut self) -> Option<Result<Info>> {
96        if self.current < self.in_count {
97            self.current += 1;
98            return Some(Info::from_iter(self.ctl, self.device, self.current-1, Direction::Capture));
99        }
100        if self.current - self.in_count < self.out_count {
101            self.current += 1;
102            return Some(Info::from_iter(self.ctl, self.device, self.current-1-self.in_count, Direction::Playback));
103        }
104
105        let r = acheck!(snd_ctl_rawmidi_next_device(ctl_ptr(self.ctl), &mut self.device));
106        match r {
107            Err(e) => return Some(Err(e)),
108            Ok(_) if self.device == -1 => return None,
109            _ => {},
110        }
111        self.current = 0;
112        match Info::subdev_count(self.ctl, self.device) {
113            Err(e) => Some(Err(e)),
114            Ok((oo, ii)) => {
115                self.in_count = ii;
116                self.out_count = oo;
117                self.next()
118            }
119        }
120    }
121}
122
123/// [snd_rawmidi_t](http://www.alsa-project.org/alsa-doc/alsa-lib/group___raw_midi.html) wrapper
124pub struct Rawmidi(*mut alsa::snd_rawmidi_t);
125
126unsafe impl Send for Rawmidi {}
127
128impl Drop for Rawmidi {
129    fn drop(&mut self) { unsafe { alsa::snd_rawmidi_close(self.0) }; }
130}
131
132impl Rawmidi {
133
134    /// Wrapper around open that takes a &str instead of a &CStr
135    pub fn new(name: &str, dir: Direction, nonblock: bool) -> Result<Self> {
136        Self::open(&CString::new(name).unwrap(), dir, nonblock)
137    }
138
139    pub fn open(name: &CStr, dir: Direction, nonblock: bool) -> Result<Rawmidi> {
140        let mut h = ptr::null_mut();
141        let flags = if nonblock { 2 } else { 0 }; // FIXME: alsa::SND_RAWMIDI_NONBLOCK does not exist in alsa-sys
142        acheck!(snd_rawmidi_open(
143            if dir == Direction::Capture { &mut h } else { ptr::null_mut() },
144            if dir == Direction::Playback { &mut h } else { ptr::null_mut() },
145            name.as_ptr(), flags))
146            .map(|_| Rawmidi(h))
147    }
148
149    pub fn info(&self) -> Result<Info> {
150        Info::new().and_then(|i| acheck!(snd_rawmidi_info(self.0, i.0)).map(|_| i))
151    }
152
153    pub fn status(&self) -> Result<Status> {
154        Status::new().and_then(|i| acheck!(snd_rawmidi_status(self.0, i.0)).map(|_| i))
155    }
156
157    pub fn drop(&self) -> Result<()> { acheck!(snd_rawmidi_drop(self.0)).map(|_| ()) }
158    pub fn drain(&self) -> Result<()> { acheck!(snd_rawmidi_drain(self.0)).map(|_| ()) }
159    pub fn name(&self) -> Result<String> {
160        let c = unsafe { alsa::snd_rawmidi_name(self.0) };
161        from_const("snd_rawmidi_name", c).map(|s| s.to_string())
162    }
163
164    pub fn io(&self) -> IO { IO(self) }
165}
166
167impl poll::Descriptors for Rawmidi {
168    fn count(&self) -> usize {
169        unsafe { alsa::snd_rawmidi_poll_descriptors_count(self.0) as usize }
170    }
171    fn fill(&self, p: &mut [pollfd]) -> Result<usize> {
172        let z = unsafe { alsa::snd_rawmidi_poll_descriptors(self.0, p.as_mut_ptr(), p.len() as c_uint) };
173        from_code("snd_rawmidi_poll_descriptors", z).map(|_| z as usize)
174    }
175    fn revents(&self, p: &[pollfd]) -> Result<poll::Flags> {
176        let mut r = 0;
177        let z = unsafe { alsa::snd_rawmidi_poll_descriptors_revents(self.0, p.as_ptr() as *mut pollfd, p.len() as c_uint, &mut r) };
178        from_code("snd_rawmidi_poll_descriptors_revents", z).map(|_| poll::Flags::from_bits_truncate(r as c_short))
179    }
180}
181
182/// Implements `std::io::Read` and `std::io::Write` for `Rawmidi`
183pub struct IO<'a>(&'a Rawmidi);
184
185impl<'a> io::Read for IO<'a> {
186    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
187        let r = unsafe { alsa::snd_rawmidi_read((self.0).0, buf.as_mut_ptr() as *mut c_void, buf.len() as size_t) };
188        if r < 0 { Err(io::Error::from_raw_os_error(r as i32)) }
189        else { Ok(r as usize) }
190    }
191}
192
193impl<'a> io::Write for IO<'a> {
194    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
195        let r = unsafe { alsa::snd_rawmidi_write((self.0).0, buf.as_ptr() as *const c_void, buf.len() as size_t) };
196        if r < 0 { Err(io::Error::from_raw_os_error(r as i32)) }
197        else { Ok(r as usize) }
198    }
199    fn flush(&mut self) -> io::Result<()> { Ok(()) }
200}
201
202
203#[test]
204fn print_rawmidis() {
205    for a in super::card::Iter::new().map(|a| a.unwrap()) {
206        for b in Iter::new(&Ctl::from_card(&a, false).unwrap()).map(|b| b.unwrap()) {
207            println!("Rawmidi {:?} (hw:{},{},{}) {} - {}", b.get_stream(), a.get_index(), b.get_device(), b.get_subdevice(),
208                 a.get_name().unwrap(), b.get_subdevice_name().unwrap())
209        }
210    }
211}
alsa/rawmidi.rs

alsa/
rawmidi.rs
