[DAFFODIL-2238] Unparser optimizers failing - couldHaveSuspensions - incorrect in many cases - needs unit tests

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.4.0
• Component/s: Middle "End"
• Assignee: Unassigned
• Reporter: Mike Beckerle
• Created: 18/Nov/19 21:11
• Updated: 18/Feb/21 20:34

Description

Many optimizations depend on the couldHaveSuspensions attribute, such as eliding out the expensive CaptureStart/End of Content/Value length for unparsing.

This appears to be true far too often. The calculation is far too pessimistic.

E.g., in an example I have which is 100% text, with only constant dfdl:outputValueCalc expressions (because there are hidden flags that must be set to constant "1" or "0"), this attribute is true, yet there is no possibility of suspension in this example.

We need unit tests to insure this is being computed correctly so that the optimizations it enables will in fact take place.