#dynamic #typed #storage

restor

A dynamic resource storage system in rust

5 releases (stable)

2.0.2 Jun 16, 2019
2.0.1 Jun 12, 2019
1.0.0 May 18, 2019
0.1.0 Apr 14, 2019

#1244 in Data structures

MIT license

88KB
1.5K SLoC

restor

Crates.io LOC A dyamic resource storage written in rust. It supports storage of multiple types and multiple entries and dynamic borrow checking with the help of RefCells, Mutexs and RwLocks from parking_lot. It also supports extracting and aqcuiring multiple types at once.

Example:

use restor::{DynamicStorage, make_storage};

fn main() {
    // Use the shorthand for creating storage with preallocated types 
    let x = make_storage!(DynamicStorage: usize, String);
    // Insert some data into the storage, either many at once, or one
    x.insert_many((0..10).collect::<Vec<usize>>()).unwrap();
    x.insert("abc".to_string()).unwrap();
    create_string(&x);
    println!("{}", &*x.get::<&String>().unwrap());
}

fn create_string(x: &DynamicStorage) {
    let mut mystring = x.get::<&mut String>().unwrap();
    for i in x.get::<&[usize]>().unwrap().iter() {
        *mystring = format!("{}, {}", &*mystring, i);
    }
}

How it works:

BlackBox (Or DynamicStorage) is defined as so (More or less):

struct BlackBox {
    data: HashMap<TypeId, Box<dyn Unit>>
}

The Unit trait allows us to abstract over the generic type of the container (Referred to as UnitStorage in the code), so we can pass data in and out of it by using the seemingly magical Any trait. When you insert something into the storage it goes through these stages:

  1. Your data in BlackBox::insert<T>
  2. Boxed into a Box<dyn Any>
  3. Passed to the StorageUnit as dyn Unit
  4. Try to downcast as either a T or a Vec<T>
  5. Put into its own place in the storage or in a Vec

Dependencies

~1.5MB
~23K SLoC