[DAFFODIL-1775] Performance - Investigate avoiding compiling non-expressions

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Assignee: Dave Thompson
• Reporter: Steve Lawrence
• Created: 11/May/17 15:34
• Updated: 11/Jul/17 15:24
• Resolved: 13/Jun/17 19:48

Description

Many properties are allowed to be DFDL expressions, but expressions are not required (e.g. dfdl:initiator, dfdl:separator). Even when these expression are provided as a constant (e.g. dfdl:inititor="foo"), we still compile them. Sometimes this is necessary for things that are numeric so that we can convert the constant string into a numeric constant. However, if the property results in a string, there really is no need to compile it into a string. Avoiding this would prevent allocating DFDLPathExpressionCompiler's and parsing/compiling a value, only to return a Constant of the same value. ��As DFDL-1774 mentions, expression compilation is very slow, so if we could avoid this, it may improve performance.