Struct LogCheckpoint

Source

pub struct LogCheckpoint<'a> { /* private fields */ }

Expand description

Borrowed complete checkpoint view; obtaining/iterating it allocates nothing. Hosts own encoding budgets. The immutable borrow keeps rows and watermarks fixed.

Implementations§

Source §

impl<'a> LogCheckpoint<'a>

Source

pub const fn limits(&self) -> Limits

Fixed retention limits.

Source

pub fn entries( &self, ) -> impl ExactSizeIterator<Item = &'a Entry> + DoubleEndedIterator + 'a

All retained rows, oldest first, without cloning text.

Source

pub const fn next_sequence(&self) -> Option<u64>

Next identity, including permanent exhaustion after complete pruning.

Examples found in repository ?

examples/worker.rs (line 44)

6fn main() {
7    let mut log = Log::new(Limits {
8        max_entries: NonZeroUsize::new(8).expect("positive capacity"),
9        max_message_bytes: 32,
10        max_label_bytes: 16,
11        max_text_bytes: 512,
12    });
13    for (created_at_secs, level, message) in [
14        (10, Level::Info, "delivery accepted"),
15        (
16            11,
17            Level::Warn,
18            "provider reply is still unknown; reconcile before retry",
19        ),
20        (12, Level::Ok, "original delivery reconciled"),
21    ] {
22        log.append(EntryInput {
23            created_at_secs,
24            level,
25            source: "worker",
26            topic: Some("delivery"),
27            message,
28        })
29        .expect("valid bounded entry");
30    }
31    let scan = log.visit_page(
32        Filter::default(),
33        PageRequest {
34            before: None,
35            max_results: NonZeroUsize::new(8).expect("positive results"),
36            max_scanned: NonZeroUsize::new(8).expect("positive scan"),
37        },
38        |entry| {
39            println!("{} {:?}: {}", entry.sequence, entry.level, entry.message);
40            ControlFlow::Continue(())
41        },
42    );
43    assert_eq!(scan.matched, 3);
44    assert_eq!(log.checkpoint().next_sequence(), Some(3));
45    let batch = log.prune_expired(16, 5, 1);
46    assert_eq!(batch.removed, 1);
47    assert_eq!(log.next_expiry_secs(5), Some(17));
48}