Allow the execution timestamp be managed by query and update builders.

[afs]

Currently, the execution "current time" (ARQConstants.sysCurrentTime) is always set unconditionally.

Allow any context given to query and update builders to retain it's settings.
Currently, it would require manipulating an already-built execution.

[divyankshah]

Hi @afs, I would like to fix this if possible. Below are the places I debugged and found out the changes would be needed -

1. Context.setCurrentDateTime(Context) (util/Context.java:448), the shared helper that unconditionally sets sysCurrentTime.

2. QueryExecDataset.init() (exec/QueryExecDataset.java:117), calls the helper above on the query-side path.

3. UpdateProcessorBase constructor (modify/UpdateProcessorBase.java:56), calls the helper above on the update-side path.

4. UpdateProcessorStreamingBase constructor (modify/UpdateProcessorStreamingBase.java:45), same call, for the streaming update entry point.

5. UpdateEngineBase.setupContext() (modify/UpdateEngineBase.java:48), a separate unconditional set that does not go through the shared helper, and fires later inside UpdateProcessorBase.execute() on the same context object.

My approach:

change Context.setCurrentDateTime(Context) to only set sysCurrentTime if it is not already defined on the context, and use it at sites 2 to 5 in place of the current unconditional calls. Since sysCurrentTime has no other source (it is not seeded on the global or dataset context by default), checking for absence is enough to tell a builder supplied value apart from one that still needs to be generated. This also means fixing site 5 with the same check is safe even though it runs after site 3, on the same context.

Please let me know if this matches what you had in mind, or if you would prefer a different approach. I am happy to open a PR once aligned and tested all changes.

[afs]

I already have the code for this.
This isn't something to get into the codebase just before a release though.

Changing Context.setCurrentDateTime to always be conditional may itself cause problems.

The UpdateEngineBase is an indication of confusion of responsibilities between UpdateProcessor and UpdateEngine - something deeper to be checked and sorted out. Query and update paths should look the same.

[divyankshah]

Hi @afs, thanks for the context. I'll check other issues.