OneIO - all-in-one IO library for Rust

OneIO is a Rust library providing unified IO operations for reading and writing compressed files from local and remote sources with both synchronous and asynchronous support.

Quick Start

oneio = "0.20"  # Default: gz, bz, https

Feature Selection Guide

Common Use Cases

Local files only:

oneio = { version = "0.20", default-features = false, features = ["gz", "bz"] }

HTTP only (no HTTPS):

oneio = { version = "0.20", default-features = false, features = ["http", "gz"] }

HTTPS with default rustls:

oneio = { version = "0.20", default-features = false, features = ["https", "gz"] }

HTTPS with custom TLS backend:

# With rustls
oneio = { version = "0.20", default-features = false, features = ["http", "rustls", "gz"] }

# With native-tls
oneio = { version = "0.20", default-features = false, features = ["http", "native-tls", "gz"] }

S3-compatible storage:

oneio = { version = "0.20", default-features = false, features = ["s3", "https", "gz"] }

Async operations:

oneio = { version = "0.20", features = ["async"] }

Available Features

Compression (choose only what you need):

• gz - Gzip via flate2
• bz - Bzip2
• lz - LZ4
• xz - XZ
• zstd - Zstandard (balanced)

Protocols:

• http - HTTP-only support (no TLS)
• https - HTTP/HTTPS with rustls TLS backend (equivalent to http + rustls)
• ftp - FTP support (requires http + TLS backend)
• s3 - S3-compatible storage

TLS Backends (for HTTPS - mutually exclusive):

• rustls - Pure Rust TLS (use with http)
• native-tls - Platform native TLS (use with http)

Additional:

• async - Async support (limited to gz, bz, zstd for compression)
• json - JSON parsing
• digest - SHA256 digest calculation
• cli - Command-line tool

Environment: Set ONEIO_ACCEPT_INVALID_CERTS=true to accept invalid certificates.

Crypto Provider Initialization: When using rustls features (https, s3, ftp), oneio automatically initializes the crypto provider (AWS-LC or ring) on first use. You can also initialize it explicitly at startup using [crypto::ensure_default_provider()] for better control over error handling.

Usages

Reading Files

Read all content into a string:

use oneio;

const TEST_TEXT: &str = "OneIO test file.\nThis is a test.";

// Works with compression and remote files automatically
let content = oneio::read_to_string("https://spaces.bgpkit.org/oneio/test_data.txt.gz")?;
assert_eq!(content.trim(), TEST_TEXT);

Read line by line:

use oneio;

let lines = oneio::read_lines("https://spaces.bgpkit.org/oneio/test_data.txt.gz")?
    .map(|line| line.unwrap())
    .collect::<Vec<String>>();

assert_eq!(lines.len(), 2);
assert_eq!(lines[0], "OneIO test file.");
assert_eq!(lines[1], "This is a test.");

Get a reader for streaming:

use oneio;
use std::io::Read;

let mut reader = oneio::get_reader("tests/test_data.txt.gz")?;
let mut buffer = Vec::new();
reader.read_to_end(&mut buffer)?;

Writing Files

Write with automatic compression:

use oneio;
use std::io::Write;

let mut writer = oneio::get_writer("output.txt.gz")?;
writer.write_all(b"Hello, compressed world!")?;
drop(writer); // Important: close the writer

// Read it back
let content = oneio::read_to_string("output.txt.gz")?;
assert_eq!(content, "Hello, compressed world!");

Remote Files with Custom Headers

use oneio;

let client = oneio::create_client_with_headers([("Authorization", "Bearer TOKEN")])?;
let mut reader = oneio::get_http_reader(
    "https://api.example.com/protected/data.json.gz",
    Some(client)
)?;

let content = std::io::read_to_string(&mut reader)?;
println!("{}", content);

Progress Tracking

Track download/read progress with callbacks:

use oneio;

let (mut reader, total_size) = oneio::get_reader_with_progress(
    "https://example.com/largefile.gz",
    |bytes_read, total_bytes| {
        match total_bytes {
            Some(total) => {
                let percent = (bytes_read as f64 / total as f64) * 100.0;
                println!("Progress: {:.1}%", percent);
            }
            None => println!("Downloaded: {} bytes", bytes_read),
        }
    }
)?;

Async Support (Feature: async)

use oneio;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let content = oneio::read_to_string_async("https://example.com/data.json.gz").await?;

    oneio::download_async(
        "https://example.com/data.csv.gz",
        "local_data.csv.gz"
    ).await?;

    Ok(())
}

Note: Async compression is limited to gz, bz, zstd. LZ4/XZ return NotSupported.

Supported Formats

Compression Detection

OneIO detects compression algorithm by the file extensions:

• Gzip: .gz, .gzip
• Bzip2: .bz, .bz2
• LZ4: .lz4, .lz
• XZ: .xz, .xz2
• Zstandard: .zst, .zstd

Protocol Support

• Local files: /path/to/file.txt
• HTTP/HTTPS: https://example.com/file.txt.gz
• FTP: ftp://ftp.example.com/file.txt (requires ftp feature)
• S3: s3://bucket/path/file.txt (requires s3 feature)

Command Line Tool

Install the CLI tool:

cargo install oneio --features cli

Basic usage:

# Read and print a remote compressed file
oneio https://example.com/data.txt.gz

# Download a file
oneio -d https://example.com/largefile.bz2

# Pipe to other tools
oneio https://api.example.com/data.json.gz | jq '.results | length'

S3 Operations (Feature: s3)

use oneio::s3::*;

// Direct S3 operations
s3_upload("my-bucket", "path/to/file.txt", "local/file.txt")?;
s3_download("my-bucket", "path/to/file.txt", "downloaded.txt")?;

// Read S3 directly
let content = oneio::read_to_string("s3://my-bucket/path/to/file.txt")?;

// Check existence and get metadata
if s3_exists("my-bucket", "path/to/file.txt")? {
    let stats = s3_stats("my-bucket", "path/to/file.txt")?;
    println!("Size: {} bytes", stats.content_length.unwrap_or(0));
}

// List objects
let objects = s3_list("my-bucket", "path/", Some("/".to_string()), false)?;

Crypto Provider Initialization (Rustls)

When using HTTPS, S3, or FTP features with rustls, oneio automatically initializes a crypto provider (AWS-LC or ring) on first use. For more control, you can initialize it explicitly at startup:

use oneio;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Initialize crypto provider explicitly at startup
    oneio::crypto::ensure_default_provider()?;

    // Now all HTTPS/S3/FTP operations will work
    let content = oneio::read_to_string("https://example.com/data.txt")?;

    Ok(())
}

This is particularly useful in libraries or applications that want to:

• Handle initialization errors early
• Control when the provider is set up
• Make the dependency on crypto providers explicit

Error Handling

Three error types in v0.20:

use oneio::OneIoError;

match oneio::get_reader("file.txt") {
    Ok(reader) => { /* use reader */ },
    Err(OneIoError::Io(e)) => { /* filesystem error */ },
    Err(OneIoError::Network(e)) => { /* network error */ },
    Err(OneIoError::NotSupported(msg)) => { /* feature not compiled */ },
}

License

MIT