Struct Daemon 

pub struct Daemon { /* private fields */ }

What a connection needs to answer the sealed surface.

Implementations

impl Daemon

pub fn new(store: PgEventStore, public_revision: String) -> Result<Self>

public_revision is the build’s own 40-hex revision, which status reports so a client can compare a running daemon against the one genesis recorded. It is required rather than defaulted: a daemon that reported a placeholder would make that comparison answer “same” for two different builds.

The writer epoch is READ OFF the store rather than passed in, because there is exactly one way to obtain one — claim_epoch, which BUMPS the durable counter — and the store already did it when it opened. A caller handed this as a parameter would have had to claim a second time, and a second claim is not a second opinion about the epoch: it supersedes the first, so the store this daemon is about to serve from would be fenced out of its own log by the daemon in front of it. A blob store is likewise required rather than optional. A store without one is a real state — admin init and the certifier drive the log with no filesystem at all — but a SERVING kernel in that state would answer every blob request with a refusal that says nothing about the request, and the operator would find out from a client rather than from a start-up that failed.

pub fn notify_on_append(&self)

Start the listener that turns database notifications into wake-ups.

Separate from Daemon::new because it spawns, and a constructor that needed a running runtime to exist would be a trap for any caller that builds a daemon before starting one. A daemon that never calls this still serves subscriptions correctly — every one of them re-reads on SUBSCRIPTION_POLL_SECS regardless — at poll latency instead of notification latency.