hexz 0.8.2

High-performance deduplicated archives

Hexz

High-performance, deduplicated archive format for large-scale data distribution.

Hexz is a single-file archive format (.hxz) designed for storing and distributing massive datasets, disk images, and binary blobs. Unlike traditional archive formats (tar, zip) or deduplication tools (Git LFS), Hexz archives are natively seekable, allowing you to mount a multi-terabyte archive and access any byte instantly without decompressing the entire file.

Key Features

• Block-Level Deduplication: Uses Content-Defined Chunking (CDC) to identify shared blocks across different versions of the same data, even if offsets shift.
• Random Access (Seekable): O(1) seek time. Mount archives via FUSE to treat them as standard block devices or filesystems.
• Thin Archives (Deltas): Create archives that only store changed blocks, referencing a "base" archive for common data. Ideal for versioning large datasets.
• Git-like Workspaces: Checkout archives into writable workspaces. Hexz creates a standard, transparent directory structure using advanced FUSE passthrough while keeping state securely isolated in global storage (~/.hexz/workspaces/).
• Transparent Compression & Encryption: Supports LZ4 and Zstandard compression, and AES-256-GCM encryption.
• Self-Contained: A single .hxz file contains the data, the index, and the metadata. No complex repository structure required.
• Cloud Native: Supports byte-range requests for on-demand fetching from S3-compatible object storage.

Why Hexz?

Feature	Git LFS	Hexz
Deduplication	File-level	Block-level (CDC)
Access Pattern	Full Download	Random Access (Seekable)
Update Efficiency	Re-upload whole file	Only upload changed blocks
Mountable	No	Yes (FUSE)

Quick Start

Install

make install

Pack an archive

hexz pack ./large_dataset.bin data.hxz --compression zstd

Mount and inspect

mkdir /mnt/data
hexz mount data.hxz /mnt/data
ls -lh /mnt/data
# Access contents via /mnt/data/disk

Create a thin delta

# Create a new version that dedups against the base
hexz pack ./large_dataset_v2.bin v2.hxz --base v1.hxz

Workspaces (Git-like Workflow)

# Checkout an archive into a writable workspace
hexz checkout data.hxz ./my_workspace
cd my_workspace

# Make changes to the mounted files
echo "New data" > README.md

# View changes
hexz status

# Commit changes to a new thin archive (delta)
hexz commit ../data_v2.hxz

Documentation

See the docs/ directory for detailed information on:

• Architecture
• CDC & Deduplication
• FUSE & NBD Mounting

License

Licensed under Apache 2.0 or MIT.