Fix memory leak in Query Processor and ProxySQL_Admin::flush_pgsql_variables___database_to_runtime

[rahim-kanji]

Addresses memory leaks in Query Processing and in ProxySQL_Admin::flush_pgsql_variables___database_to_runtime

[gemini-code-assist]

Summary of Changes

Hello @rahim-kanji, 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 addresses critical memory leaks identified in two key areas of the system: the Query Processor's rule management and the ProxySQL_Admin's PostgreSQL variable flushing mechanism. The changes ensure that dynamically allocated memory is properly released, improving the application's stability and resource utilization.

Highlights

• Query Processor Memory Management: Ensured proper deallocation of client_addr and proxy_addr fields within QP_rule_t structures by adding free calls in the __delete_query_rule function (lines 132-134).
• Admin Variable Flush Memory Management: Removed an unnecessary get_variable_string call and its associated assert in ProxySQL_Admin::flush_pgsql_variables___database_to_runtime (lines 741-742 removed), which was likely causing a memory leak by not freeing the returned string.

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[gemini-code-assist]

Code Review

This pull request addresses two memory leaks, one in the query processor and another in the admin variable flushing logic. The changes are straightforward and correct:

1. In lib/Query_Processor.cpp, missing free() calls for client_addr and proxy_addr in __delete_query_rule have been added, preventing a memory leak when query rules are deleted or reloaded.
2. In lib/Admin_FlushVariables.cpp, an unused variable previous_default_client_encoding was being allocated but never freed. The removal of this variable correctly plugs the leak.

Both changes are well-targeted and effectively resolve the described memory leak issues. The code quality is maintained, and the fixes are consistent with the existing memory management patterns in the codebase. This is a good contribution to improving the stability of the application.

[renecannao]

Can one of the admins verify this patch?

[renecannao]

add to whitelist

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud