HPCC-35431 Avoid using accessors to calculate offsets in compare functions

[ghalliday]

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[github-actions]

Jira Issue: https://hpccsystems.atlassian.net//browse/HPCC-35431

Jirabot Action Result:
Assigning user: [email protected]
Workflow Transition To: Merge Pending
Updated PR

[Copilot]

Pull request overview

This PR implements a performance optimization to avoid using accessor classes when generating comparison functions in the ECL compiler. Row accessor classes pre-calculate offsets for all fields in a record, but comparison functions often terminate early before accessing all fields, making this pre-calculation wasteful. The change adds a delayOffsetCalculation parameter to bindTableCursor methods that, when set to true, bypasses accessor class creation.

• Adds delayOffsetCalculation parameter to bindTableCursor methods to control accessor class usage
• Applies optimization to buildReturnOrder function which generates comparison methods
• Updates inline wrapper functions to maintain backward compatibility with default false value

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
ecl/hqlcpp/hqlcpp.ipp	Adds avoidAccessor parameter (default false) to bindTableCursor method declarations and updates inline wrapper functions to pass the parameter
ecl/hqlcpp/hqlhtcpp.cpp	Implements delayOffsetCalculation parameter in bindTableCursor methods to conditionally disable accessor classes; applies optimization in buildReturnOrder for compare functions

[Copilot]

Typo in comment: "leaving to" should be "leading to".

Suggested change

	// function will terminate long before the latter fields are accessed - leaving to significantly
	// function will terminate long before the latter fields are accessed - leading to significantly

[Copilot]

Parameter name inconsistency: The parameter is named avoidAccessor in the header but delayOffsetCalculation in the implementation (hqlhtcpp.cpp:7408, 7419). These names should match. The implementation name delayOffsetCalculation better describes what the parameter does (delays offset calculation by avoiding accessor classes), so consider updating the header to use delayOffsetCalculation instead of avoidAccessor.

Suggested change

	BoundRow * bindTableCursor(BuildCtx & ctx, IHqlExpression * dataset, const char * bound, bool isLinkCounted, node_operator no_side, IHqlExpression * selSeq, bool avoidAccessor = false);
	BoundRow * bindTableCursor(BuildCtx & ctx, IHqlExpression * dataset, IHqlExpression * bound, node_operator no_side, IHqlExpression * selSeq, bool avoidAccessor = false);
	BoundRow * bindTableCursor(BuildCtx & ctx, IHqlExpression * dataset, const char * bound, bool isLinkCounted, node_operator no_side, IHqlExpression * selSeq, bool delayOffsetCalculation = false);
	BoundRow * bindTableCursor(BuildCtx & ctx, IHqlExpression * dataset, IHqlExpression * bound, node_operator no_side, IHqlExpression * selSeq, bool delayOffsetCalculation = false);

[Copilot]

Minor formatting inconsistency: There is an extra space after bound, (two spaces instead of one). Should be bound, no_none to match the formatting of the other inline functions.

Suggested change

	{ return bindTableCursor(ctx, dataset, bound, no_none, NULL, false); }
	{ return bindTableCursor(ctx, dataset, bound, no_none, NULL, false); }