Crate dwarfs_enc

A library for writing DwarFS archives (aka. images), building on top of dwarfs crate.

For reading archives only, check dwarfs crate instead.

Currently, this crate writes DwarFS archive with filesystem version v2.5, which should be compatible with upstream dwarfs v0.7.0..=v0.12.4 (latest at the time of writing).

Examples

use dwarfs_enc::{
    chunker::{Chunker, BasicChunker, CdcChunker},
    metadata::{Builder as MetaBuilder, InodeMetadata},
    section::{Writer as SectionWriter, CompressParam},
};
use std::{fs, time::SystemTime};

let f = fs::File::create("out.dwarfs")?;

// Create inode metadata.
let mut dir_meta = InodeMetadata::new(0o755);
dir_meta.uid(1000).gid(1000).atime(SystemTime::now());
// ... or initialize from OS metadata.
let file_meta = InodeMetadata::from(&fs::metadata("./bar")?);

// Create a hierarchy builder initialized with a root inode.
let mut meta = MetaBuilder::new(&dir_meta);

// Use ZSTD compression level 22, Content Defined Chunking (CDC) for deduplication.
let compress = CompressParam::Zstd(22);
let writer = SectionWriter::new(f)?;
let chunker = BasicChunker::new(writer, meta.block_size(), compress);
let mut chunker = CdcChunker::new(chunker);

// Put a directories and a symlink.
let root = meta.root();
let subdir = meta.put_dir(root, "subdir", &dir_meta)?;
meta.put_symlink(subdir, "symlink", &file_meta, "./subdir")?;

// Put a regular file, using in-memory data.
meta.put_file(root, "foo", &file_meta, chunker.put_bytes(b"hello world")?)?;
// Put a regular file, reading from an OS File.
let chunks = chunker.put_reader(&mut fs::File::open("bar")?)?;
let bar = meta.put_file(root, "bar", &file_meta, chunks)?;

// Hard links are also supported.
meta.put_hard_link(root, "hardlink", bar)?;

// Finalizing data chunks, metadata, and section writer in order.
let mut writer = chunker.finish()?;
writer.write_metadata_sections(&meta.finish()?, compress)?;
writer.finish()?;

See also the simple mkdwarfs impl at ./examples/mkdwarfs.rs.

Cargo features

• zstd, lzma (Only zstd is enabled by default)

  Enable relevant compression algorithm support. zstd is the default compression algorithm mkdwarfs uses and it should be enough for most cases.

Modules

chunker

File data slicing and/or deduplication.

metadata

DwarFS archive hierarchy builder.

section

DwarFS section writer.

Structs

Error

An error representing any possible error raised from this crate.

Type Aliases

Result

A Result with default error Error.