Run Length Encoder

Run-length encoding (RLE) is a form of lossless data compression in which runs of data (consecutive occurrences of the same data value) are stored as a single occurrence of that data value and a count of its consecutive occurrences, rather than as the original run.

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Overview

This project provides a fast and simple implementation of Run-Length Encoding (RLE) in Rust, along with utilities for benchmarking and testing. It includes:

• A Rust CLI tool for compressing and decompressing files using RLE.
• Utility functions for efficient file I/O with progress bars.
• A C++ utility to generate large input files for testing and benchmarking.

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Project Structure

rl_encoding/
├── Cargo.toml            # Rust project manifest
├── generate_input.cpp    # C++ utility to generate large input files
└── src/
    ├── main.rs           # entry point
    ├── rle.rs            # RLE compression/decompression
    ├── utils.rs          # File I/O utilities with progress bars
    └── lib.rs            # (Optional) Rust library file

Usage

Generating Sample Input

Compile the generate_input.cpp with aggressive compilation flags as it generates large output file (~100MB)

g++ generate_input.cpp -o gen -O3 -std=c++20 -flto -march=native
./gen

This will generate a large_input.txt which can be used to test and benchmark this project.

Compress a File

cargo run -- compress <input_file> <output_file>

Decompress a File

cargo run -- decompress <input_file> <output_file>

Check Output

You can verify that decompression restores the original data:

diff <input> <output>
# No output means files are identical

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Features

• Efficient file reading and writing with progress bars (see src/utils.rs).
• Simple and fast RLE compression/decompression (see src/rle.rs).
• Example C++ generator for large test files.

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License

This project is licensed under the MIT License.