Function getMotionState

src/backend/executor/execUtils.c:2283–2298

* Given a slice index, find the motionstate that corresponds to this slice index. This will iterate over the planstate tree * to get the right node. */

 * to get the right node.
 */
MotionState *
getMotionState(struct PlanState *ps, int sliceIndex)
{
	Assert(ps);
	Assert(sliceIndex > -1);

	MotionStateFinderContext ctx;
	ctx.motionId = sliceIndex;
	ctx.motionState = NULL;
	planstate_walk_node(ps, MotionStateFinderWalker, &ctx);

	if (ctx.motionState == NULL)
		elog(ERROR, "could not find MotionState for slice %d in executor tree", sliceIndex);

	return ctx.motionState;
}

typedef struct MotionFinderContext
{