Crate memoria

memoria

A bad memory “profiler” for production.

1. Define a UseCase enum.
2. Use memoria’s custom allocator.
3. Assign usecases to functions or blocks of code using Alloc::with_usecase.
4. Get basic memory usage statistics per-usecase, either at the end of your program or periodically in a background thread.

Documentation, Crates.io

use num_enum::{TryFromPrimitive, IntoPrimitive};

#[derive(TryFromPrimitive, IntoPrimitive, Default, Debug)]
#[repr(u32)]
enum MyUseCase {
    #[default]
    None,
    LoadConfig,
    ProcessData,
}

impl memoria::UseCase for MyUseCase {}

#[global_allocator]
static ALLOCATOR: memoria::Alloc<MyUseCase> = memoria::Alloc::new();

fn load_config() {
    let _guard = ALLOCATOR.with_usecase(MyUseCase::LoadConfig);
    println!("loading config...");
    // consume some memory
    let _temporary = vec![0u8; 256];
}

fn process_data() {
    let _guard = ALLOCATOR.with_usecase(MyUseCase::ProcessData);
    // consume some more memory
    let _temporary = vec![0u8; 2048];
}

fn main() {
    load_config();
    process_data();

    println!("memory usage stats:");
    ALLOCATOR.with_recorder(|recorder| {
        recorder.flush(
            |usecase, stat| {
                println!("{usecase:?}: {stat:?}");
            },
            |err, count| {
                println!("{err:?}: {count}");
            }
        );
        Ok(())
    }).ok();
}

License

Licensed under the MIT license, see ./LICENSE.

Structs

Alloc

A wrapper around another allocator A that records memory usage statistics into R.

Guard

A drop-guard for setting and resetting the current usecase.

Stat

Basic memory stats for a given usecase.

StatsRecorder

A simple recorder for memory statistics that can be flushed periodically.

Enums

Error

an error encountered by memoria that caused it to drop stats, such as a detected deadlock that caused it to drop metrics.

Traits

Recorder

A recorder is a structure collecting statistics about memory usage. You might also call it a “metrics sink”.

UseCase

A UseCase is a struct describing what the application is currently doing. Memory statistics are recorded per distinct value of UseCase.

Type Aliases

UseCaseBytes

The internal representation memoria uses to represent instances of UseCase.