fix: fixed Postgres driver CPU 100%

[lvca]

This fixes the issue with CPU 100% when the postgres driver has an open connection.

The issue was with the read from the socket: if no data is present, a spin lock like behavior happens inside the read. Now if the data is not present, sleep 100ms and check again.

The idea would be implementing a multiplexing poll, this is a quick fix.

[gemini-code-assist]

Hello @lvca, 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!

Summary of Changes

Hello, gemini-code-assist here! This pull request by @lvca addresses a critical issue where the Postgres driver could consume 100% CPU when an open connection was idle. The core fix involves modifying the message reading loop to avoid busy-waiting when no data is available on the network channel. Additionally, a minor change in a test file disables Postgres debug logging by default.

Highlights

• Fix CPU Usage: Implemented a check in the readMessage method of the PostgresNetworkExecutor to prevent a tight loop when no data is available on the channel. If no data is present, the thread now sleeps for 100ms, resolving the 100% CPU usage issue.
• Test Configuration Update: Changed the default value for GlobalConfiguration.POSTGRES_DEBUG to false in the PostgresWJdbcTest class, disabling debug logging by default in tests.

Changelog

• postgresw/src/main/java/com/arcadedb/postgres/PostgresNetworkExecutor.java
  • Added import for com.arcadedb.utility.CodeUtils (line 46).
  • In the readMessage method, added a check if (!channel.inputHasData()) (line 1078).
  • If no input data is available, the method now calls CodeUtils.sleep(100) (line 1079) and returns false (line 1080), preventing a busy-wait loop.
• postgresw/src/test/java/com/arcadedb/postgres/PostgresWJdbcTest.java
  • Changed the default value of GlobalConfiguration.POSTGRES_DEBUG from true to false (line 58) in the setTestConfiguration method.

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---

Channel waits for data,
Looping fast, CPU hot,
Now it sleeps a bit.

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[gemini-code-assist]

Code Review

The pull request introduces a fix for a high CPU usage issue in the Postgres driver by adding a sleep interval when the input channel has no data. This is a good, direct approach to prevent busy-waiting. The change in the test file to disable debug logging is also a sensible cleanup.

Overall, the main change effectively addresses the reported problem. I have one suggestion regarding the use of a magic number for the sleep duration to improve maintainability.

Summary of Findings

• Magic Number for Sleep Duration: The sleep duration of 100 ms in PostgresNetworkExecutor.java is a magic number. It's recommended to define it as a named constant (e.g., NETWORK_IDLE_SLEEP_MS) for better readability and maintainability.

Merge Readiness

The pull request effectively addresses the high CPU usage issue. There's one medium-severity suggestion to improve maintainability by replacing a magic number with a named constant. Addressing this would be beneficial before merging.

As an AI reviewer, I am not authorized to approve pull requests. Please ensure other human reviewers inspect and approve these changes.

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ -0.05%	✅ 100.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (0deebdd)	72348	46148	63.79%
Head commit (52da3d1)	72351 (+3)	46113 (-35)	63.74% (-0.05%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#2229)	3	3	100.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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[robfrank]

Ooook, maybe in the future we can do better :)