fix: remove an unnecessary shared_lock in hot path

[cheniujh]

问题：每次写binlog 后，在ConsensusCoordinator::InternalAppendBinlog结尾，都要执行一次stable_logger_->Logger()->GetProducerStatus(&filenum, &offset)， 但是这里的filenum, offset取了之后根本不用，只是取用了这个函数的返回值。而这里面要取filenum, offset要对全局唯一的version_对象加锁，尽管只是shared_lock，但这个锁对象是一把全局都在抢的锁，而且这个位置是热点，开启binlog的情况下，每一条请求都要去做这件事情，这就会有较大竞争，最重要的是这个竞争是完全没有必要的。

这个PR做的事情是将GetProducerStatus中除了＂加锁获取filename, offset＂之外的逻辑复制封装成了一个新的函数 IsOpened(),该函数同GetProducerStatus有一样的返回值，用于在ConsensusCoordinator::InternalAppendBinlog替换对GetProducerStatus的调用。

Issue: Each time after writing "bingo", at the end of the ConsensusCoordinator::InternalAppendBinlog function, the stable_logger_->Logger()->GetProducerStatus(&filenum, &offset) is executed. However, the filenum and offset variables are not used after being retrieved; only the return value of this function is utilized. Acquiring these variables requires locking the globally unique version_ object, even though it is just a shared_lock, which is a lock object that is highly contended globally. This spot is a hotspot, and in scenarios where binlog is enabled, each request has to perform this action, leading to significant competition. More crucially, this competition is entirely unnecessary.

This PR addresses the issue by copying and encapsulating the logic within GetProducerStatus, except for the "locking and retrieving filenum and offset" part, into a new function called IsOpened(). This new function has the same return value as GetProducerStatus and is utilized to replace the call to GetProducerStatus in ConsensusCoordinator::InternalAppendBinlog.

Summary by CodeRabbit

• New Features
  • Introduced a method to check if the binlog is open, enhancing log management and diagnostics.

[coderabbitai]

Walkthrough

The changes primarily introduce a new method IsOpened() in the Binlog class to verify if the binlog is open. This adjustment extends to checking the binlog's status in the InternalAppendBinlog function of the ConsensusCoordinator class. These updates help streamline status checking within the Pika system.

Changes

File	Change Summary
include/pika_binlog.h	Added IsOpened() method declaration in Binlog class.
src/pika_binlog.cc	Implemented IsOpened() method in Binlog class.
src/pika_consensus.cc	Modified InternalAppendBinlog to use IsOpened() method for status checking.

Sequence Diagram(s)

sequenceDiagram
    participant Client
    participant ConsensusCoordinator
    participant Binlog

    Client->>ConsensusCoordinator: InternalAppendBinlog(cmd)
    ConsensusCoordinator->>Binlog: IsOpened()
    Binlog-->>ConsensusCoordinator: Status (Open/Closed)
    ConsensusCoordinator-->>Client: Return Status

Loading

Poem

In the code where logs align,
A status check, a sign so fine.
IsOpened speaks, the bins reveal,
Streamlined flow, like rabbit’s zeal.
With every change, the system's prime,
Hopping forth in perfect rhyme.
🐰🚀✨

---

Tip

Early access features: enabled

We are currently testing the following features in early access:

• OpenAI gpt-4o model for code reviews and chat: OpenAI claims that this model is better at understanding and generating code than the previous models. We seek your feedback over the next few weeks before making it generally available.

Note:

• You can enable or disable early access features from the CodeRabbit UI or by updating the CodeRabbit configuration file.
• Please join our Discord Community to provide feedback and report issues.
• OSS projects are currently opted into early access features by default.

Thank you for using CodeRabbit. We offer it for free to the OSS community and would appreciate your support in helping us grow. If you find it useful, would you consider giving us a shout-out on your favorite social media?

Share

• X
• Mastodon
• Reddit
• LinkedIn

Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>.
  • Generate unit testing code for this file.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
  • @coderabbitai generate unit testing code for this file.
  • @coderabbitai modularize this function.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai generate interesting stats about this repository and render them as a table.
  • @coderabbitai show all the console.log statements in this repository.
  • @coderabbitai read src/utils.ts and generate unit testing code.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
  • @coderabbitai help me debug CodeRabbit configuration file.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (invoked as PR comments)

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Additionally, you can add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.

CodeRabbit Configration File (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.

[coderabbitai]

Actionable comments posted: 0

Review details

Configuration used: CodeRabbit UI
Review profile: CHILL

Commits

Files that changed from the base of the PR and between c259401 and 7218ee1.

Files selected for processing (3)

• include/pika_binlog.h (1 hunks)
• src/pika_binlog.cc (1 hunks)
• src/pika_consensus.cc (1 hunks)

Additional comments not posted (3)

include/pika_binlog.h (1)

55-55: New Method IsOpened Added

The IsOpened method checks if the binlog is open and returns an appropriate status. This is a good addition to reduce contention in the hot path.

src/pika_binlog.cc (1)

148-153: New Method IsOpened Implementation

The IsOpened method is implemented correctly. It checks if the binlog is open and returns an appropriate status. This will help reduce contention in the hot path.

src/pika_consensus.cc (1)

377-377: Optimized InternalAppendBinlog Method

The InternalAppendBinlog method now calls IsOpened instead of GetProducerStatus, reducing unnecessary locking and contention in the hot path. This change is well-aligned with the PR objective.