jojodiff-rs

Rust library for working with JojoDiff files

The original Jojos Binary Diff tool can be found at https://jojodiff.sourceforge.net/ and https://sourceforge.net/projects/jojodiff/

This library is a Rust implementation of the JojoDiff file format. It is intended to be used as a library for other Rust projects that need to work with JojoDiff files.

Currently, it only supports applying JojoDiff patch files to binary files.

Usage

cargo add jojodiff

• Check the docs at https://docs.rs/jojodiff
• Check the unit tests in src/lib.rs for examples.

Logging

This library uses the log crate for logging. See https://docs.rs/log/latest/log/ for more information on how to select a logger implementation and configuring it.

Running tests

cargo test

Running a single test with logging:

RUST_LOG=debug cargo test patch_copy_seq_3_times

JojoDiff patch file format

The JojoDiff patch file format is a binary stream containing operands that describe how to transform an original file into a destination file.

The stream consists of a series of
  <op> (<data> || <len>)
where
  <op>   = <ESC> (<MOD>||<INS>||<DEL>||<EQL>||<BKT>)
  <data> = <chr>||<ESC><ESC>
  <chr>  = any byte different from <ESC><MOD><INS><DEL><EQL> or <BKT>
  <ESC><ESC> yields one <ESC> byte

Where:

• <ESC> (0xA7) escape: Indicates that the next byte is an operand.
• <MOD> (0xA6) modify: Replaces bytes from the original file with bytes from the patch file.
• <INS> (0xA5) insert: Inserts bytes from the patch file into the destination file.
• <DEL> (0xA4) delete: Skips bytes from the original file.
• <EQL> (0xA3) equal: Copies bytes from the original file to the destination file.
• <BKT> (0xA2) backtrack: Seeks backwards in the original file.