Implement Zlib compression (Standard Library Compliant)

[Krishna200608]

Issue: #72

FIX: Implemented object compression using zlib (Deflate) in src/data.py.

Rationale & Trade-offs

I selected zlib after evaluating lzma, bz2, and zstd against the project's requirements.

1. Constraint Compliance (No External Dependencies):

   • zstd: While zstd is often cited as a superior algorithm, it requires the zstandard package (not in the Python Standard Library until 3.14+). This violates the project's "External Dependencies: NONE" rule stated in README.md.
   • zlib: Is part of the Python Standard Library, ensuring the project remains dependency-free.

2. Performance (Speed vs Size):

   • lzma: Offers higher compression ratios but is significantly slower (high CPU cost). For a VCS that commits hundreds of files, this latency is unacceptable for the "hot path."
   • zlib: The industry standard for Git-like systems. It offers an excellent balance of speed and storage efficiency.

Benchmark Results

Tested using the provided file diff.c (Vim source code).

Metric	Value
Original Size	~126 KB (129,580 bytes)
Compressed Size (zlib)	~35 KB (35,824 bytes)
Space Savings	~72% Reduction
Compression Ratio	3.6 : 1

Conclusion: zlib provides significant storage savings (shrinking the file to nearly 1/4th its size) while maintaining the low latency required for a responsive CLI.

[OpenGitBot]

Hey @Krishna200608

Thanks for opening this PR 🚀. Mentor will review your pull request soon and till then, keep contributing and stay calm.

Thanks for contributing in OpenCode'25 ✨✨!

[Rational-Idiot]

Thank you for the research and foresight :D

[OpenGitBot]

Hey @Krishna200608

Your PR has been merged 🥳🥳 and you have earned 30 points.

Thanks for contributing in OpenCode'25✨✨