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ClockSource

audio_clock_bsd::clock

Trait ClockSource 

Source 
pub trait ClockSource: Send {
    // Required methods
    fn ptp_now_ns(&self) -> Result<i64>;
    fn sample_to_ptp(&self, sample_idx: i64) -> i64;
    fn ptp_to_sample(&self, ptp_ns: i64) -> i64;
}
Expand description

A source of PTP-aligned time that can map between sample indices and timestamps.

ClockSource is the single contract a host uses to timestamp audio samples. Concrete implementations (an NtpClock fallback or a PtpClock) own a ClockAnchor and a backing time reference.

§Threading

Implementations are Send but not real-time-safe in general: ClockSource::ptp_now_ns may block (polling a daemon, reading a device) and must run off the RT audio thread. The pure-conversion methods ClockSource::sample_to_ptp and ClockSource::ptp_to_sample are allocation-free and safe to call from the RT thread.

§Example

A minimal anchor-only clock (no live time source) implementing the trait:

use audio_clock_bsd::{ClockAnchor, ClockError, ClockSource, Result};

struct AnchorClock {
    anchor: ClockAnchor,
}

impl ClockSource for AnchorClock {
    fn ptp_now_ns(&self) -> Result<i64> {
        // A real clock would read its backing time source here.
        Err(ClockError::Unavailable("no live source".into()))
    }
    fn sample_to_ptp(&self, sample_idx: i64) -> i64 {
        self.anchor.sample_to_ptp_checked(sample_idx).unwrap_or(i64::MIN)
    }
    fn ptp_to_sample(&self, ptp_ns: i64) -> i64 {
        self.anchor.ptp_to_sample_checked(ptp_ns).unwrap_or(i64::MIN)
    }
}

Required Methods§

Source

fn ptp_now_ns(&self) -> Result<i64>

Returns the current PTP timestamp in nanoseconds since the epoch.

This may block (daemon poll, device read) — call from a worker thread.

§Errors
Source

fn sample_to_ptp(&self, sample_idx: i64) -> i64

Converts a sample index to a PTP timestamp in nanoseconds.

Pure arithmetic over the clock’s anchor — allocation-free, RT-safe. Implementations MUST NOT panic; on internal overflow they return a sentinel (i64::MIN) so the RT path is never aborted.

Source

fn ptp_to_sample(&self, ptp_ns: i64) -> i64

Converts a PTP timestamp in nanoseconds to a sample index.

Pure arithmetic over the clock’s anchor — allocation-free, RT-safe. Implementations MUST NOT panic; on internal overflow they return a sentinel (i64::MIN).

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§