OPFS Rust

Rust wrapper for the the Origin Private File System browser API. When compiling to native platforms, falls back to tokio::fs.

Overview

This crate provides an API for file system operations that automatically uses the appropriate implementation based on the target platform:

• Web (WASM): Uses the Origin Private File System (OPFS) API
• Native platforms: Uses tokio::fs

An in-memory filesystem is also provided for use in tests (or when persistence isn't necessary)

Features

• Write once, run anywhere: The same code works natively and on the web
• Async/await: All operations are asynchronous
• Type safety: The type-unsafe JsValue soup associated with working with browser APIs from Rust is hidden behind a type-safe API.

Installation

cargo add opfs

Usage

use opfs::persistent::{DirectoryHandle, FileHandle, WritableFileStream, app_specific_dir};
use opfs::{GetFileHandleOptions, CreateWritableOptions};
use opfs::persistent;

// you must import the traits to call methods on the types
use opfs::{DirectoryHandle as _, FileHandle as _, WritableFileStream as _};

// This code works on both native and web platforms
async fn example(dir: DirectoryHandle) -> persistent::Result<()> {
    let options = GetFileHandleOptions { create: true };
    let mut file = dir.get_file_handle_with_options("example.txt", &options).await?;
    
    let write_options = CreateWritableOptions { keep_existing_data: false };
    let mut writer = file.create_writable_with_options(&write_options).await?;
    
    writer.write_at_cursor_pos(b"Hello, world!".to_vec()).await?;
    writer.close().await?;
    
    let data = file.read().await?;
    println!("File contents: {:?}", String::from_utf8(data));
    
    Ok(())
}

async fn use_example() -> persistent::Result<()> {
    let directory: DirectoryHandle = app_specific_dir().await?;
    example(directory).await?;
    Ok(())
}