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Introduction to Rit

Welcome to Rit - a Git implementation written from scratch in Rust!

Created by Sudeep Ranjan Sahoo | GitHub | Documentation | LinkedIn | Twitter/X

What is Rit?​

Rit is an educational project that reimplements Git's core functionality to understand:

  1. How version control actually works - Not just using Git, but understanding its internals
  2. Rust systems programming - File I/O, binary data, hashing, compression
  3. Data structures - Content-addressable storage, DAGs, merkle trees

Why Build Your Own Git?​

"I hear and I forget. I see and I remember. I do and I understand." - Confucius

Reading about Git internals is one thing. Building it forces you to truly understand:

  • Why Git uses SHA-1 hashes
  • How commits form a linked list (DAG)
  • Why the staging area exists
  • How branching is just moving pointers

Architecture Overview​

┌─────────────────────────────────────────────────────────────┐
│                      Working Directory                       │
│                    (your actual files)                       │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼ rit add
┌─────────────────────────────────────────────────────────────┐
│                      Staging Area (Index)                    │
│                   (.rit/index - binary file)                 │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼ rit commit
┌─────────────────────────────────────────────────────────────┐
│                      Object Database                         │
│                      (.rit/objects/)                         │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐                  │
│  │  Blobs   │  │  Trees   │  │ Commits  │                  │
│  │ (files)  │  │  (dirs)  │  │(snapshots│                  │
│  └──────────┘  └──────────┘  └──────────┘                  │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                      References                              │
│              (.rit/refs/ and .rit/HEAD)                      │
│  ┌──────────────────┐  ┌──────────────────┐                │
│  │  refs/heads/main │  │   refs/tags/v1   │                │
│  │  (commit hash)   │  │   (commit hash)  │                │
│  └──────────────────┘  └──────────────────┘                │
└─────────────────────────────────────────────────────────────┘

Quick Start​

# Build Rit
cargo build --release

# Initialize a repository
./target/release/rit init

# Hash a file
./target/release/rit hash-object -w README.md

# Read it back
./target/release/rit cat-file -p <hash>

# Create a tree from current directory
./target/release/rit write-tree

# List tree contents
./target/release/rit ls-tree <tree-hash>

Project Structure​

src/
├── main.rs          # CLI entry point
├── lib.rs           # Library root, Repository struct
├── commands/        # Command implementations
│   ├── init.rs
│   ├── hash_object.rs
│   └── cat_file.rs
└── objects/         # Git object types
    ├── blob.rs
    ├── tree.rs
    └── commit.rs

Learning Resources​