Crate async_file

Asynchronous file I/O operations with priority handling.

async_file provides a simple yet powerful API for performing asynchronous file operations in Rust. It closely follows the standard library’s file API design while adding async support and priority-based scheduling.

Features

• Async Operations: All file operations are asynchronous, allowing for non-blocking I/O
• Priority Scheduling: Every operation accepts a priority parameter for fine-grained control
• Memory Safety: Uses an opaque Data type to safely handle OS-managed memory allocations
• Platform Agnostic: Backend-agnostic API with a default std implementation

Quick Start

use async_file::{File, Priority};

// Open a file with unit test priority
let file = File::open("/dev/zero", Priority::unit_test()).await?;

// Read up to 1KB of data
let data = file.read(1024, Priority::unit_test()).await?;
println!("Read {} bytes", data.len());

Design Philosophy

This library enforces that only one operation may be in-flight at a time per file handle. This constraint simplifies the implementation and prevents many classes of concurrency bugs.

The library uses opaque types (File, Data, Metadata) that wrap platform-specific implementations, providing a clean abstraction layer while maintaining efficiency.

Structs

Data

An opaque buffer type that holds data read from files.

Error

An error that can occur during file operations.

File

A handle to an open file for asynchronous I/O operations.

Metadata

Metadata information about a file.

Functions

exists

Tests if a file or directory exists at the given path.

Type Aliases

Priority

A priority value for scheduling file operations.