Log-to-tune matching
Every log records the tune it started on, plus each ECU write and burn.
When efi2000 records an MLG log, it writes the tune revision and a hash of the tune contents into the log, and marks each ECU write and burn with a timestamp. When you review the log later, you can see which tune it started on and where the ECU was changed during the recording.
What is recorded
The MLG info text starts with the saved tune revision, a hash of the tune contents and the project. The hash changes whenever the tune contents change, including edits you haven't saved as a new revision.
Writes and burns during a drive
Each ECU write and burn made while logging is added as an ordinary log marker with its time and result. Edits that only reach ECU RAM are shown as writes and don't create a saved revision.
Standard file formats
The tune information uses the info text and markers MLG already supports. The logs open in MegaLogViewer and TunerStudio, and tunes still export as MSQ.
Example
You record three pulls and write a VE change between the second and third. The log shows the starting tune revision and a write marker before the third pull, so you know the first two pulls ran on the starting tune and the third came after a change.
The problem it solves
Logs and tunes are usually separate files with only a date to connect them. A few weeks later it's hard to tell which tune a log came from, and a log read against the wrong tune leads to the wrong correction.