vec_mem_heap ( MOVED )

After the major rework v0.8, this crate has finally been given a new name and moved it it's (hopefully) permanent home at https://crates.io/crates/lilypads.

This crate will no longer recieve updates.

lib.rs:

Fun little object pool allocator.

This is a learning experience for me, but I'm fairly confident it doesn't suck that badly.

This crate was originally intended for the creation of tree-like datastructures, where indexes could be used instead of dealing with rust's reference/pointer system. The vision of the project has somewhat shifted since v0.8 and is now intended as a general purpose object pool, for whatever you need to be pooling. It attempts to keep data as contiguous as possible, Pond::alloc reserves the first (sequentially) free node and Pond::defrag + Pond::trim are provided to maintain contiguity on otherwise sparse allocations.

This crate isn't yet thread safe, but that's eventually on the todo list probably.

Example

use lilypads::Pond;

fn main() {
  let mut pool = Pond::new();
  // You can push data into the pond and recieve their index.
  let idx1 = pool.alloc(57);
  let idx2 = pool.alloc(42);

  // Data is retrieved with get
  let data1 = pool.get(idx1).unwrap();
  assert_eq!(*data1, 57);
  // And get_mut
  let data2 = pool.get_mut(idx2).unwrap();
  *data2 = 13;
  assert_eq!(*pool.get(idx2).unwrap(), 13);

  // Data can be freed with free, which will return the data stored at the index.
  let freed1 = pool.free(idx1).unwrap();
  assert_eq!(freed1, 57);
  assert_eq!(pool.get_mut(idx1), None);

  // You can request a specific index with write, overwriting the existing data 
  // and returning whatever used to be there
  let replaced = pool.write(idx2, 98);
  assert_eq!(*pool.get(idx2).unwrap(), 98);

  let far_idx = 17;
  let nothing = pool.write(far_idx, 1000);
  assert_eq!(nothing, None);
  assert_eq!(*pool.get(far_idx).unwrap(), 1000);
  
}