[PROTON-2375] Make connection driver more efficient when finishing writes

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-c-0.34.0
• Fix Version/s: proton-c-0.35.0
• Component/s: cpp-binding, proton-c
• Assignee: Andrew Stitcher
• Reporter: Andrew Stitcher
• Created: 21/Apr/21 02:10
• Updated: 02/Jul/21 15:10
• Resolved: 21/Apr/21 02:34

Description

This is a small ABI preserving change to the connection_driver API which makes the process of informing the connection_driver that writes have been completed and the buffer can be returned more efficient.

pn_connection_driver_write_done() is changed to return any new bytes that may have been generated up to this point so that the proactor (or other event loop) doesn't have to immediately query for them.

Note this is ABI preserving because previously there was no return value so code couldn't be using it. If old code ignores the return value then this is no change in behaviour.