timerwheel 0.1.0

// Copyright © 2026-present The Timerwheel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::sync::Arc;

use crate::timing_wheel::entry::Entry;

#[derive(Debug, Default)]
pub(crate) struct Bucket {
    expiration_ms: Option<u64>,
    entries: Vec<Arc<Entry>>,
}

impl Bucket {
    pub(crate) fn expiration_ms(&self) -> Option<u64> {
        self.expiration_ms
    }

    pub(crate) fn set_expiration_ms(&mut self, expiration_ms: u64) -> bool {
        if self.expiration_ms == Some(expiration_ms) {
            return false;
        }
        self.expiration_ms = Some(expiration_ms);
        true
    }

    pub(crate) fn add(&mut self, entry: Arc<Entry>) {
        self.entries.push(entry);
    }

    pub(crate) fn drain(&mut self) -> Vec<Arc<Entry>> {
        self.expiration_ms = None;
        std::mem::take(&mut self.entries)
    }
}

#[cfg(test)]
mod tests {
    use std::sync::Arc;

    use crate::timing_wheel::entry::Entry;
    use crate::timing_wheel::state::TimeoutState;

    use super::Bucket;

    #[test]
    fn bucket_drains_entries_and_clears_expiration() {
        let mut bucket = Bucket::default();
        let entry = Arc::new(Entry::new(1, 10, Arc::new(TimeoutState::scheduled())));

        assert!(bucket.set_expiration_ms(10));
        bucket.add(Arc::clone(&entry));
        assert_eq!(bucket.drain().len(), 1);
        assert_eq!(bucket.expiration_ms(), None);
        assert!(bucket.drain().is_empty());
    }
}