infinite-db 0.4.0

//! Per Hilbert-shard live tail views (format v4).

use std::sync::Arc;

use dashmap::DashMap;

use crate::infinitedb_core::address::SpaceId;

use super::hilbert_shard::ShardKey;
use super::live_tail::LiveTailView;

/// One [`LiveTailView`] per `(space_id, hilbert_shard_id)` pair.
pub struct HilbertLiveTails {
    tails: DashMap<ShardKey, Arc<LiveTailView>>,
}

impl HilbertLiveTails {
    pub fn new() -> Self {
        Self {
            tails: DashMap::new(),
        }
    }

    pub fn get_or_create(&self, space_id: SpaceId, shard_id: u32) -> Arc<LiveTailView> {
        let key = ShardKey::new(space_id, shard_id);
        if let Some(t) = self.tails.get(&key) {
            return Arc::clone(t.value());
        }
        let tail = Arc::new(LiveTailView::new());
        self.tails.insert(key, Arc::clone(&tail));
        tail
    }

    pub fn get(&self, space_id: SpaceId, shard_id: u32) -> Option<Arc<LiveTailView>> {
        self.tails
            .get(&ShardKey::new(space_id, shard_id))
            .map(|e| Arc::clone(e.value()))
    }

    /// All shard tails registered for `space_id`.
    pub fn tails_for_space(&self, space_id: SpaceId) -> Vec<Arc<LiveTailView>> {
        self.tails
            .iter()
            .filter(|e| e.key().space_id == space_id)
            .map(|e| Arc::clone(e.value()))
            .collect()
    }

    /// Load each shard's consistent view for `space_id` (one load per shard).
    pub fn views_for_space(
        &self,
        space_id: SpaceId,
    ) -> Vec<arc_swap::Guard<std::sync::Arc<super::shard_view::ShardView>>> {
        self.tails
            .iter()
            .filter(|e| e.key().space_id == space_id)
            .map(|e| e.value().load_view())
            .collect()
    }

    pub fn len(&self) -> usize {
        self.tails.len()
    }
}

impl Default for HilbertLiveTails {
    fn default() -> Self {
        Self::new()
    }
}