Struct PrioritySource 

pub struct PrioritySource<I> {
    pub priority: i32,
    pub stream: I,
}

A source + the priority it carries. Higher priority wins on key ties. Equal-priority ties fall through to registration order (the index in the new(...) argument list).

Fields

priority: i32

stream: I

Implementations

impl<I> PrioritySource<I>

pub fn new(priority: i32, stream: I) -> Self

Examples found in repository

examples/perf_features.rs (line 486)

fn priority_sources(n: usize) -> Vec<PrioritySource<std::vec::IntoIter<PriorityEntry<u64, u64>>>> {
    let per = n / STREAMS;
    (0..STREAMS)
        .map(|s| {
            let stream = (0..per)
                .map(move |i| {
                    let key = ((s + i * STREAMS) as u64) / 2;
                    PriorityEntry::new(key, key)
                })
                .collect::<Vec<_>>()
                .into_iter();
            PrioritySource::new((STREAMS - s) as i32, stream)
        })
        .collect()
}

examples/sample_app.rs (lines 212-219)

fn memtable_wins_the_read() {
    use subms_merge_iterator::{PriorityEntry, PriorityMergeIterator, PrioritySource};
    println!("\n== priority: the memtable is authoritative ==");
    let memtable = PrioritySource::new(
        100,
        PRICE_MEMTABLE
            .iter()
            .map(|&(k, v)| PriorityEntry::new(k, v))
            .collect::<Vec<_>>()
            .into_iter(),
    );
    let flushed = PrioritySource::new(
        10,
        PRICE_FLUSHED
            .iter()
            .map(|&(k, v)| PriorityEntry::new(k, v))
            .collect::<Vec<_>>()
            .into_iter(),
    );

    let view: Vec<(&str, i64)> = PriorityMergeIterator::new([memtable, flushed])
        .map(|e| (e.key, e.value))
        .collect();
    println!("  resolved read view: {view:?}");
    assert_eq!(
        view,
        vec![("AAPL", 152), ("MSFT", 300)],
        "the memtable wins AAPL despite being registered first"
    );
}