FineZip

Overview

FineZip is a novel approach to lossless text compression using Large Language Models (LLMs). Building on previous work like LLMZip, FineZip pushes the boundaries of text compression by integrating both online memorization and dynamic context size techniques. These innovations lead to significant improvements in compression speed while maintaining competitive compression ratios compared to both traditional methods (e.g., gzip, bzip2) and neural network-based methods (e.g., NNCP, LLMZip). FineZip compresses text 54 times faster than LLMZip with a minor loss in compression performance. FineZip with Arithmetic coding also improves on LLMZip's AC approach by adding batch encoding and decoding.

Main Contributions:

1. FineZip combines "online" memorization using parameter-efficient fine-tuning (PEFT) and "offline" pre-trained LLMs for text compression, enabling faster compression without sacrificing too much performance.
2. A dynamic context window allows batching of compression steps, significantly improving the compression speed.
3. Quantization techniques further optimize performance by reducing memory requirements, allowing larger batch sizes and faster compression times.
4. Arithmetic Coding LLM Compression allows batched encoding and decoding with Arithmetic Coding for LLM compression.

File Structure

Here's an overview of the files included in this codebase:

• finezip/eval.py:

  • The main script implementing FineZip compression using LLM-based techniques with online memorization and dynamic context handling.
  • creates a ZipModel that implements the zipping/unzipping
  • function named memory_eval that allows for testing with multiple kinds of models (both base and finetuned), context sizes, and batch sizes

• finezip/finetune.py

  • The script that allows you to finetune models using LoRA and QLoRA
  • allows you to finetune multiple models at a time with different hyperparams

• AC/arithmeticcoding.py

  • This is the Arithemetic Coding Python code created by Project Nayuki
  • We are using this to perform Arithematic Encoding from LLM output logits

• AC/eval_ac.py

  • The main script implementing FineZip compression with Arithmetic Encoding with fixed context size and batching.
  • Creates a Encoder for encoding, and a Decoder for decoding the encoded files
  • Use verify_text function to verify the correctness of the decoded text.