//! Burritos stores a data structure associating object ids with
//! their references. The ObjAddr struct
//! allows to maintain this data structure.

use std::collections::HashMap;

pub trait SynchObj { }

/// Brief Definition of object identifiers:
/// 
/// The struct stores the list of created objects (Semaphore, Lock, ...) and for each of them
/// associates an object identifier than can be passed to subsequent
/// system calls on the object.
/// 
/// A method allows to detect of an object corresponding to a given
/// identifier exists; this is used to check the parameters of system
/// calls.
struct ObjAddr<'a> {
    last_id: i32,
    map: HashMap<i32, &'a dyn SynchObj>
}

impl<'a> ObjAddr<'a> {
    
    /// Initializes and returns a ObjAddr struct
    pub fn init() -> Self {
        Self {
            last_id: 3,
            map: HashMap::<i32, &dyn SynchObj>::new()
        }
    }

    /// Adds the **obj** SynchObj to self
    pub fn add_object(&mut self, obj: &'a dyn SynchObj) -> i32 {
        self.last_id = self.last_id + 1;
        self.map.insert(self.last_id, obj);
        self.last_id
    }

    /// Searches for an object of id **id** in self
    pub fn search_object(&self, id: i32) -> Option<&& dyn SynchObj> {
        self.map.get(&id)
    }

    /// Removes the object of id **id** from self if it exists
    pub fn remove_object_from_key(&mut self, id: i32) {
        self.map.remove(&id);
    }

}