fix: Use single query instead of batch query for DQL

[sitaowang1998]

Description

#83 introduces batch query in get_ready_tasks and get_task_timeout. However, DQLs like SELECT does not support batch query. In bulk mode, it only executes the last query. This pr fixes the problem by using a single query with subqueries.

Checklist

• The PR satisfies the contribution guidelines.
• This is a breaking change and that has been indicated in the PR title, OR this isn't a
  breaking change.
• Necessary docs have been updated, OR no docs need to be updated.

Validation performed

• GitHub workflows pass
• Unit tests pass in dev container
• Integration tests pass in dev container

Summary by CodeRabbit

• Refactor
  • Enhanced backend efficiency by streamlining task retrieval and timeout processing.
  • Consolidated database interactions to improve performance, resulting in a faster and more reliable experience when handling tasks.

[coderabbitai]

Walkthrough

This pull request refactors SQL statement management within the MySqlStorage module by replacing the use of prepared statements with standard statements in the get_ready_tasks and get_task_timeout methods. The refactoring consolidates multiple SQL operations into single queries, reducing the number of database interactions and enhancing result handling. No public or exported APIs were modified.

Changes

File	Change Summary
src/spider/storage/mysql/.../MySqlStorage.cpp	Replaced std::unique_ptr<sql::PreparedStatement> with std::unique_ptr<sql::Statement> in get_ready_tasks and get_task_timeout, consolidating queries and updating result handling.

Sequence Diagram(s)

sequenceDiagram
    participant App as Application
    participant Storage as MySqlStorage
    participant DB as Database

    App->>Storage: Call get_ready_tasks / get_task_timeout
    Storage->>DB: Create Statement & Execute consolidated query
    DB-->>Storage: Return query results
    Storage-->>App: Process and return results

Loading

Possibly related PRs

• fix: Batch MySQL queries in getting ready tasks #83: Addresses modifications in get_ready_tasks and get_task_timeout by introducing ScheduleTaskMetadata.
• fix: Retry deadlocked task_finish call #77: Involves updates in MySqlStorage.cpp focusing on SQL query execution and error management.
• feat: Add MySql support for storage backend #20: Directly related to refactoring SQL statement handling within the MySQL storage backend for task management.

---

📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2dee0a8 and fedfb29.

📒 Files selected for processing (1)

• src/spider/storage/mysql/MySqlStorage.cpp (8 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (3)

• GitHub Check: lint
• GitHub Check: non-storage-unit-tests (ubuntu-22.04)
• GitHub Check: non-storage-unit-tests (ubuntu-24.04)

🔇 Additional comments (8)

src/spider/storage/mysql/MySqlStorage.cpp (8)

1239-1247: Well-implemented refactoring to use standard statements instead of prepared statements.

The change from prepared statements to standard statements with a single comprehensive query is a good approach to solve the batch query limitation with DQL commands.

---

1269-1276: Good consolidation of job metadata query.

This change properly replaces batch queries with a single query using subqueries, which aligns with the PR's objective of fixing the DQL batch query limitation.

---

1300-1311: Effective consolidation of data localities query.

The query has been properly refactored to use a single statement with subqueries instead of batch queries, addressing the core issue.

---

1324-1337: Good addition of task deduplication logic.

The new code checks if tasks already exist in the tasks vector before adding them, which is important to prevent duplicates when using single queries that might return multiple results for the same task.

---

1631-1645: Well-implemented fix for the task timeout query.

The refactoring from prepared statements to standard statements with a comprehensive query correctly addresses the batch query limitation for DQL commands.

---

1662-1676: Appropriate consolidation of job metadata query in the get_task_timeout method.

This change follows the same pattern as in get_ready_tasks, providing consistency in how the issue is addressed throughout the codebase.

---

1700-1716: Effective refactoring of data localities query in get_task_timeout.

The query has been properly consolidated into a single statement with subqueries, aligning with the PR's objective.

---

1729-1737: Good implementation of task deduplication in get_task_timeout.

This follows the same pattern as in get_ready_tasks, ensuring consistency in how tasks are managed across the codebase.

✨ Finishing Touches

• 📝 Generate Docstrings

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ 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>, please review it.
  • 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 gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @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 using 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 generate docstrings to generate docstrings for this PR.
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai plan to trigger planning for file edits and PR creation.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration 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.