Bug #71861 Avoid manual array copy in MysqlIO and LoadBalancingConnectionProxy

• Submitted: 27 Feb 2014 9:52
• Modified: 10 Mar 2014 16:07
• Reporter: Andrej Golovnin (OCA)
• Status: Closed
• Category: Connector / J
• Severity: S5 (Performance)
• Version: 5.1.29
• OS: Any
• Assigned to: Filipe Silva
• CPU Architecture: Any
• Tags: jdbc, LoadBalancingConnectionProxy, MysqlIO

[27 Feb 2014 9:52] Andrej Golovnin

Description:
In the methods MysqlIO#unpackNativeEncodedColumn and LoadBalancingConnectionProxy#addHost a manual loop is used to copy array values. To improve the performance System#arraycopy should be used instead. Oracle's HotSpot hast intrinsics for System#arraycopy which results in better performance.

How to repeat:
Just review the code of the methods MysqlIO#unpackNativeEncodedColumn and LoadBalancingConnectionProxy#addHost.

Suggested fix:
See attached patch.

[27 Feb 2014 9:53] Andrej Golovnin

Patch for this issue.

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: manual_array_copy.patch (application/octet-stream, text), 1.30 KiB.

[28 Feb 2014 9:54] Filipe Silva

Hi Andrej,

Thank you for this bug report.

[28 Feb 2014 9:56] Filipe Silva

Verified by code review and patch accepted. Thanks.

[28 Feb 2014 10:46] Alexander Soklakov

Hi Andrej,

Contribution accepted, thank you!

[10 Mar 2014 16:07] Daniel So

Added the following entry into the Connector/J 5.1.30 changelog:

"Replaced a for loop with the System.arraycopy() method for copying array values in the MysqlIO.unpackNativeEncodedColumn() and LoadBalancingConnectionProxy.addHost() methods, in order to improve the two methods' performance."