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Version: 3.0.0-rc.2

Create UDF filesystems

hadris-udf writes mastered, read-only type 1 UDF volumes from a hadris::fs::Tree. write_bridge writes a shared ISO/UDF bridge image.

Dependency​

[dependencies.hadris]
version = "3.0.0-rc.2"
default-features = false
features = ["std", "sync", "udf", "iso"]

Create a volume​

use hadris::fs::{Content, Node, Tree};
use hadris::udf::UdfOptions;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut tree = Tree::new();
    tree.insert("README.txt", Node::file(Content::bytes("Hello from a UDF image\n")))?;
    tree.insert("docs/guide.txt", Node::file(Content::bytes("UDF guide\n")))?;

    let target = hadris::storage::host::FileDevice::new(std::fs::File::create("volume.udf")?)?;
    let report = hadris::udf::sync::write(target, &tree, &UdfOptions::default())?;
    println!("wrote {} bytes", report.size());
    Ok(())
}

A FileDevice over a host file grows as the writer writes it, and so does a Vec<u8>. For a fixed-size device such as a MemDevice, size it with hadris::udf::plan(&tree, &options) first, which does no I/O; write refuses a device that is too small before writing anything. hadris::fs::host::read_tree imports a host directory without reading the files until the image is written.

Select a mastered revision​

use hadris::udf::{UdfId, UdfOptions, UdfRevision};

let options = UdfOptions::default()
    .with_id(UdfId::Volume, "ARCHIVE_2026")
    .with_revision(UdfRevision::V2_01);

The revision describes a mastered, read-only image. It does not enable packet writing, VAT, sparing, metadata partitions or pseudo-overwrite. Choose the oldest revision that gives your consumers what they need, and validate with their tools.

Names, metadata and limits​

Names are encoded as OSTA Compressed Unicode: 8-bit when every character is below U+0100, 16-bit otherwise. A name over 254 encoded bytes fails with NameTooLong. Symlinks and hard links are stored; device nodes, creation times and DOS attributes are left out and listed in Report::warnings. The options' time, NoClock::TIME (1980-01-01) by default, dates entries without times, so the same tree gives the same bytes; with_time sets another. The volume set identifier starts with a 16-digit serial derived from with_seed, or the time, and the tree's paths, sizes and times; with_id(UdfId::VolumeSet, ..) sets it outright.

Author an ISO/UDF bridge​

Do not concatenate separate ISO and UDF images. A bridge coordinates descriptor locations, directory ICBs and payload extents. hadris::udf::sync::write_bridge(dev, &tree, &iso_options, &udf_options) writes one, and hadris::udf::plan_bridge plans it without I/O. Both namespaces point at the same file data. From the command line:

hadris udf bridge image-root -o bridge.iso -J
hadris udf compare bridge.iso

Validate the result​

udfinfo volume.udf
7z l volume.udf
hadris udf check volume.udf

7-Zip does not open volumes that contain symlinks. For interoperability work, also create reference images with mkudffs and confirm that Hadris reads them.