txmap 0.1.0

A concurrent transactional hash map with fine-grained locking and internal mutability
Documentation 
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use crate::{indexer::Indexer, ops::op_trait::OpTrait, result::MISSING_MUTEX_GUARD_ERROR};
use hashbrown::HashMap;
use intmap::IntMap;
use parking_lot::MutexGuard;
use std::{hash::Hash, marker::PhantomData};

pub(crate) struct InsertDefaultOp<K, V> {
    guards_bitmask: u128,
    key_index: u8,
    key: K,
    _phantom: PhantomData<V>,
}

impl<K, V> InsertDefaultOp<K, V>
where
    K: Hash,
{
    pub fn new(indexer: &Indexer, key: K) -> Self {
        let key_index = indexer.index(&key);
        Self {
            guards_bitmask: 1 << key_index,
            key_index,
            key,
            _phantom: PhantomData,
        }
    }
}

impl<K, V, P> OpTrait<K, V, P> for InsertDefaultOp<K, V>
where
    K: Clone + Hash + Eq,
    V: Default,
{
    fn guards_bitmask(&self) -> u128 {
        self.guards_bitmask
    }
    fn apply(&self, mutex_guards: &mut IntMap<u8, MutexGuard<'_, HashMap<K, V>>>, _: &P) {
        let mutex_guard = mutex_guards
            .get_mut(self.key_index)
            .expect(MISSING_MUTEX_GUARD_ERROR);
        let new_value = V::default();
        mutex_guard.insert(self.key.clone(), new_value);
    }
}