refactor(pm): use real streaming write

[xusd320]

Real streaming write for package tgz entries.

[gemini-code-assist]

Summary of Changes

Hello @xusd320, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refactors the package manager's tgz extraction logic to implement a true streaming write mechanism. The primary goal is to enhance memory efficiency and simplify the internal architecture by processing tar entries directly from the incoming stream to the filesystem, rather than buffering their entire contents in memory. This change results in a more robust and scalable unpacking process, particularly beneficial when dealing with large package files.

Highlights

• Memory Efficiency: The tgz extraction process now uses direct streaming writes, avoiding buffering entire tar entry contents in memory. This significantly reduces memory consumption, especially for large files.
• Simplified Architecture: The previous two-stage pipeline, which involved separate extraction and file writing tasks communicating via mpsc channels, has been replaced with a single, more direct streaming process.
• Dependency Reduction: Unnecessary imports like tokio::io::AsyncReadExt, tokio::sync::Semaphore, and tokio::sync::mpsc have been removed, streamlining the codebase.
• Code Clean-up: The ExtractedEntry struct, which was used to temporarily hold buffered file contents, has been removed as it is no longer needed with the new streaming approach.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request refactors the package unpacking logic to use a true streaming approach, which is a great improvement. By using tokio::io::copy, it avoids reading entire file entries into memory, significantly reducing memory consumption and simplifying the code by removing the complex two-stage pipeline with channels and semaphores. The changes make the code more maintainable and robust. I have a couple of suggestions to further simplify the code by removing concurrency primitives that are no longer necessary in the new sequential implementation.