laminar_connectors/connector/
recency.rs

1//! Real-time recency: how far a source's upstream has been written, so a committed read can wait
2//! for a checkpoint that holds everything the source could see when the read arrived.
3
4use std::fmt::Debug;
5use std::time::Instant;
6
7use async_trait::async_trait;
8
9use crate::checkpoint::SourceCheckpoint;
10use crate::error::ConnectorError;
11
12/// Reports how far a source's upstream has been written. It is built from the source's
13/// configuration on any node and never touches the running reader or its position.
14#[async_trait]
15pub trait SourceRecency: Send + Sync + Debug {
16    /// The upstream's end now: every record a reader of this source could see.
17    ///
18    /// # Errors
19    ///
20    /// Returns an error when the upstream cannot be reached or described before `deadline`.
21    async fn upstream_end(
22        &self,
23        deadline: Instant,
24    ) -> Result<Box<dyn RecencyTarget>, ConnectorError>;
25}
26
27/// The upstream's end at one instant.
28#[async_trait]
29pub trait RecencyTarget: Send + Sync + Debug {
30    /// Whether `checkpoint`, a committed checkpoint of this source, holds every record before
31    /// this end. Positions only grow, so a later checkpoint of a covering one also covers it.
32    ///
33    /// # Errors
34    ///
35    /// Returns an error when `checkpoint` is not this connector's, or coverage cannot be decided
36    /// before `deadline`.
37    async fn covered_by(
38        &self,
39        checkpoint: &SourceCheckpoint,
40        deadline: Instant,
41    ) -> Result<bool, ConnectorError>;
42}
laminar_connectors/connector/recency.rs

laminar_connectors/connector/
recency.rs
