Large Vector

Rust Vector for large amounts of data, that does not copy when growing, by using full mmap'd pages.

Maturity

I made ths to learn about mmap.

This is a first draft, testing out my idea. I copied the doctests from alloc::vec::Vec and they all pass.

I only have one test, where it grows until the virtual address changes , and data still look good.

Next Steps

• On shrinking, madvise(MADV_FREE)
• Performance Test

Memory Use

Creating huge vectors does not increase the memory usage immediately. The following line only makes the OS assign 8GB of virtual address in the Process.

let mut vec = LVec::<usize>::with_capacity(1024 * 1000 * 1000);

physical memory is only allocated when you actually use the page.

The same is true for alloc::vec::Vec, so it does not seem that this crate provides any benefit over standard vector.

License

Licensed under either of

• Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)

• MIT license (http://opensource.org/licenses/MIT)

at your option.