libmoq 0.6.7

Media over QUIC, C bindings
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

//! Session bandwidth allocator and per-track reservation, mirroring
//! [`moq_net::bandwidth`].

use std::sync::Arc;

use crate::{Error, Id, NonZeroSlab, State, ffi};

/// Allocators minted from a session, plus the reservations taken against them.
#[derive(Default)]
pub(crate) struct Bandwidth {
	allocators: NonZeroSlab<moq_net::bandwidth::Allocator>,
	reservations: NonZeroSlab<Arc<moq_net::bandwidth::Reservation>>,
}

impl Bandwidth {
	pub fn insert(&mut self, allocator: moq_net::bandwidth::Allocator) -> Result<Id, Error> {
		self.allocators.insert(allocator)
	}

	pub fn allocator(&self, id: Id) -> Result<moq_net::bandwidth::Allocator, Error> {
		self.allocators.get(id).cloned().ok_or(Error::NotFound)
	}

	pub fn close(&mut self, id: Id) -> Result<(), Error> {
		self.allocators.remove(id).ok_or(Error::NotFound)?;
		Ok(())
	}

	pub fn reserve(&mut self, allocator: Id, demand: &moq_net::track::Demand, max_bps: u64) -> Result<Id, Error> {
		let allocator = self.allocator(allocator)?;
		let reservation = allocator.reserve(demand, moq_net::bandwidth::Rate::from_bps(max_bps));
		self.reservations.insert(Arc::new(reservation))
	}

	pub fn hold(&mut self, reservation: Arc<moq_net::bandwidth::Reservation>) -> Result<Id, Error> {
		self.reservations.insert(reservation)
	}

	pub fn reservation(&self, id: Id) -> Result<Arc<moq_net::bandwidth::Reservation>, Error> {
		self.reservations.get(id).cloned().ok_or(Error::NotFound)
	}

	pub fn reservation_close(&mut self, id: Id) -> Result<(), Error> {
		self.reservations.remove(id).ok_or(Error::NotFound)?;
		Ok(())
	}
}

/// The session's bandwidth allocator. Clones share one reservation registry.
///
/// Returns a non-zero handle, or a negative error if the session is unknown.
#[unsafe(no_mangle)]
pub extern "C" fn moq_session_bandwidth(session: u32) -> i32 {
	ffi::enter(move || {
		let session = ffi::parse_id(session)?;
		let mut state = State::lock();
		let allocator = state.session.bandwidth(session)?;
		state.bandwidth.insert(allocator)
	})
}

/// Release a bandwidth handle. Reservations taken against it stay until they
/// themselves are closed (or the session's allocator is gone).
#[unsafe(no_mangle)]
pub extern "C" fn moq_bandwidth_close(bandwidth: u32) -> i32 {
	ffi::enter(move || {
		let bandwidth = ffi::parse_id(bandwidth)?;
		State::lock().bandwidth.close(bandwidth)
	})
}

/// Reserve up to `max_bps` for `track`, returning a reservation handle.
///
/// `max_bps` is a ceiling, not a measurement: reserve the most the track can
/// ever send. Drop the reservation with [`moq_reservation_close`] to hand the
/// room back.
#[unsafe(no_mangle)]
pub extern "C" fn moq_bandwidth_reserve(bandwidth: u32, track: u32, max_bps: u64) -> i32 {
	ffi::enter(move || {
		let bandwidth = ffi::parse_id(bandwidth)?;
		let track = ffi::parse_id(track)?;
		let mut state = State::lock();
		let demand = state.publish.track_demand(track)?;
		state.bandwidth.reserve(bandwidth, &demand, max_bps)
	})
}

/// This reservation's slice right now, in bits per second.
///
/// `present` is false when there is no estimate or no demand: hold the current
/// rate. `present` true and `bps` 0 is a real zero grant.
///
/// # Safety
/// - `bps` and `present` must be valid pointers.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn moq_reservation_grant(reservation: u32, bps: *mut u64, present: *mut bool) -> i32 {
	ffi::enter(move || {
		let reservation = ffi::parse_id(reservation)?;
		let bps = unsafe { bps.as_mut() }.ok_or(Error::InvalidPointer)?;
		let present = unsafe { present.as_mut() }.ok_or(Error::InvalidPointer)?;
		match State::lock().bandwidth.reservation(reservation)?.peek() {
			Some(rate) => {
				*bps = rate.as_bps();
				*present = true;
			}
			None => {
				*bps = 0;
				*present = false;
			}
		}
		Ok(())
	})
}

/// Change the ceiling, keeping the same claim.
#[unsafe(no_mangle)]
pub extern "C" fn moq_reservation_update(reservation: u32, max_bps: u64) -> i32 {
	ffi::enter(move || {
		let reservation = ffi::parse_id(reservation)?;
		State::lock()
			.bandwidth
			.reservation(reservation)?
			.update(moq_net::bandwidth::Rate::from_bps(max_bps));
		Ok(())
	})
}

/// Release a reservation, handing its share back to siblings.
///
/// Closing an accessor returned by a video or audio producer does not release
/// the encoder's claim; that lasts until the producer is finished.
#[unsafe(no_mangle)]
pub extern "C" fn moq_reservation_close(reservation: u32) -> i32 {
	ffi::enter(move || {
		let reservation = ffi::parse_id(reservation)?;
		State::lock().bandwidth.reservation_close(reservation)
	})
}