Adds proto fields for overwriting fetch/write state functionality

[wolfchris-google]

Adds protos to ProcessBundleRequest that will later enable skipping fetching/writing state input.

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Mention the appropriate issue in your description (for example: addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, comment fixes #<ISSUE NUMBER> instead.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI or the workflows README to see a list of phrases to trigger workflows.

[gemini-code-assist]

Summary of Changes

Hello @wolfchris-google, 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 introduces foundational changes to the Beam Fn API by adding new fields to the "ProcessBundleRequest" protocol buffer. The primary purpose is to provide mechanisms for controlling state management during bundle processing, allowing for future optimizations where the SDK can intelligently skip state fetch and write operations. This enhancement aims to improve the efficiency of data processing by reducing redundant state interactions.

Highlights

• Proto Definition Update: Two new boolean fields, "key_has_no_state" and "only_bundle_for_key", have been added to the "ProcessBundleRequest" message in "beam_fn_api.proto". These fields are designed to enable control over state fetching and writing behavior within the SDK.
• Future State Optimization: These newly introduced proto fields lay the groundwork for future functionality that will allow the SDK to skip unnecessary state fetching and writing operations, potentially improving performance and efficiency.

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. ↩

[wolfchris-google]

r: @kennknowles r: @ryan-mbuashundip this is an updated PR of my previous changes. Thought just making a new PR would be easier than cleaning the old one.

[github-actions]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control. If you'd like to restart, comment assign set of reviewers

[ryan-mbuashundip]

LGTM

[kennknowles]

Bundles are not restricted to have a single key. In fact they very frequently have a whole key range. Do these booleans mean that no key in the bundle has any state / has any further bundles?

In addition to resolving that issue, please document more fully and focus on semantics/specification/requirements.

For example:

• only_bundle_for_key: Indicates that the runner will never process another bundle for the [keys in this bundle] so state need not be included in the bundle commit.
• key_has_no_state: Indicates that the runner has no state for the [keys in this bundle] so an SDK can safely begin stateful processing with a locally-generated initial empty state.

[ryan-mbuashundip]

Bundles are not restricted to have a single key. In fact they very frequently have a whole key range.

Is this true for streaming as well?

Do these booleans mean that no key in the bundle has any state / has any further bundles?

Given that state is a function of the operation/transform I believe this is safe to assume.
Thanks for the example blurbs, I think they cover the intention of the bits well. Given your clarification, has_no_keyed_state and only_bundle_for_keys are better names for these bits.

[wolfchris-google]

I have updated the fields and use your recommended comments for documentation. Thanks!

[wolfchris-google]

@kennknowles please re-review when you get a chance!