mbx 1.18.0

A build cache for Rust projects
Documentation 
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use super::*;

#[test]
fn combined_budget_reserves_the_full_action_store_allowance() {
    let retention = RetentionSettings {
        target_max_bytes: Some(80),
        target_max_age: None,
        incremental_max_bytes: Some(20),
        incremental_max_age: None,
        max_total_bytes: Some(100),
    };

    assert_eq!(target_budget(&retention, 70, 10), Some(20));
    assert_eq!(target_budget(&retention, 120, 10), Some(0));
    assert_eq!(incremental_budget(&retention, 70), Some(20));
    assert_eq!(incremental_budget(&retention, 90), Some(10));
    assert_eq!(incremental_budget(&retention, 120), Some(0));
    assert_eq!(store_budget(&retention, 70, 30), 70);
    assert_eq!(store_budget(&retention, 70, 60), 40);
}

#[test]
fn the_sweep_report_is_said_once() {
    let directory = tempfile::tempdir().unwrap();
    let store = directory.path();
    crate::util::write_atomic(
        &store.join(SWEEP_REPORT),
        b"removed 2 target directories\n\nevicted 3 objects\n",
    )
    .unwrap();

    assert_eq!(
        take_sweep_report(store),
        vec![
            "removed 2 target directories".to_string(),
            "evicted 3 objects".to_string()
        ]
    );
    assert!(
        take_sweep_report(store).is_empty(),
        "the second reader finds nothing"
    );
    let left = std::fs::read_dir(store.join("gc/v1"))
        .unwrap()
        .filter_map(|entry| entry.ok())
        .filter(|entry| {
            entry
                .file_name()
                .to_string_lossy()
                .starts_with("last-sweep-report")
        })
        .count();
    assert_eq!(
        left, 0,
        "neither the report nor its claimed copy is left behind"
    );
}

#[test]
fn no_report_means_nothing_to_say() {
    let directory = tempfile::tempdir().unwrap();

    assert!(take_sweep_report(directory.path()).is_empty());
}

#[test]
fn an_automatic_sweep_that_is_not_due_leaves_no_report() {
    let directory = tempfile::tempdir().unwrap();
    let mut config = super::cargo_tests::managed_target_config(directory.path());
    config.gc.auto = true;
    config.gc.interval = std::time::Duration::from_secs(3600);
    assert!(crate::store::claim_sweep(&config.store_dir(), config.gc.interval).unwrap());

    run_automatic(&config, &RetentionSettings::default()).unwrap();

    assert!(!config.store_dir().join(SWEEP_REPORT).exists());
}

#[test]
fn an_automatic_sweep_stands_down_while_another_collector_holds_the_store() {
    let directory = tempfile::tempdir().unwrap();
    let mut config = super::cargo_tests::managed_target_config(directory.path());
    config.gc.auto = true;
    config.gc.interval = std::time::Duration::ZERO;
    let store = config.store_dir();
    let mut other = collector_lock(&store).unwrap();
    assert!(other.try_lock().unwrap());

    run_automatic(&config, &RetentionSettings::default()).unwrap();

    assert!(
        !store.join("gc/v1/last-sweep").exists(),
        "the sweep was neither claimed nor run"
    );
}

#[test]
fn sweep_reports_accumulate_until_a_build_says_them() {
    let directory = tempfile::tempdir().unwrap();
    let store = directory.path();
    for report in ["first\n", "second\n"] {
        std::fs::create_dir_all(store.join("gc/v1")).unwrap();
        std::fs::OpenOptions::new()
            .create(true)
            .append(true)
            .open(store.join(SWEEP_REPORT))
            .and_then(|mut file| std::io::Write::write_all(&mut file, report.as_bytes()))
            .unwrap();
    }

    assert_eq!(take_sweep_report(store), ["first", "second"]);
}

#[test]
fn a_build_leaves_the_report_alone_while_a_collector_writes_it() {
    let directory = tempfile::tempdir().unwrap();
    let store = directory.path();
    crate::util::write_atomic(&store.join(SWEEP_REPORT), b"evicted 3 objects\n").unwrap();
    let mut collector = collector_lock(store).unwrap();
    assert!(collector.try_lock().unwrap());

    assert!(
        take_sweep_report(store).is_empty(),
        "not while the collector holds it"
    );

    collector.unlock().unwrap();
    assert_eq!(take_sweep_report(store), ["evicted 3 objects"]);
}

#[test]
fn leftovers_of_an_interrupted_collection_are_reported() {
    let units = crate::target::CollectionOutcome {
        removed_units: 3,
        removed_unit_bytes: 2048,
        ..Default::default()
    };
    let leftovers = crate::target::CollectionOutcome {
        removed_unit_bytes: 2048,
        ..Default::default()
    };

    assert_eq!(
        target_removals(&units, false),
        ["removed 3 unused build units from live target directories (2.0 KiB logical)"]
    );
    assert_eq!(
        target_removals(&leftovers, true),
        [
            "would remove build units an interrupted collection left in live target directories (2.0 KiB logical)"
        ]
    );
    assert!(target_removals(&crate::target::CollectionOutcome::default(), false).is_empty());
}