txmap 2.1.0

A concurrent transactional hash map for Rust with fine-grained locking, internal mutability and composable transactions
Documentation 
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use crate::{
    immediate::ops::op_trait::OpTrait, key::TxKey, lock_guards::LockGuards,
    lock_policies::lock_policy::LockPolicy, new_types::BitMask, result::MISSING_LOCK_GUARD_ERROR,
};
use std::hash::Hash;

pub(crate) struct ModifyOp<'tx, K, V, STATE>
where
    K: Hash + Eq,
{
    pub key: TxKey<K>,
    #[allow(clippy::type_complexity)]
    pub mutate: Box<dyn Fn(&K, &mut V, &mut STATE) + 'tx>,
}

impl<'tx, K, V, L, STATE> OpTrait<K, V, L, STATE> for ModifyOp<'tx, K, V, STATE>
where
    K: Hash + Eq + 'tx,
    V: 'tx,
    L: LockPolicy + 'tx,
{
    fn read_write_bitmasks(&self) -> (BitMask, BitMask) {
        (BitMask::ZERO, self.key.shard_index.bitmask())
    }
    fn apply(&self, lock_guards: &mut LockGuards<'_, K, V, L>, state: &mut STATE) {
        let write_guard = lock_guards
            .write
            .get_mut(self.key.shard_index.0)
            .expect(MISSING_LOCK_GUARD_ERROR);
        if let Some(mut_entry) =
            write_guard.find_mut(self.key.hash_code.0, |entry| entry.0 == self.key.key)
        {
            (self.mutate)(&mut_entry.0, &mut mut_entry.1, state)
        }
    }
}