public PlanEnumeration escape()

in wayang-commons/wayang-core/src/main/java/org/apache/wayang/core/optimizer/enumeration/PlanEnumeration.java [553:595]
34 lines of code
10 McCabe index (conditional complexity)

    public PlanEnumeration escape(OperatorAlternative.Alternative alternative) {
        if (alternative == null) return this;
        PlanEnumeration escapedInstance = new PlanEnumeration();
        final OperatorAlternative operatorAlternative = alternative.getOperatorAlternative();

        // Copy and widen the scope.
        escapedInstance.scope.addAll(this.scope);
        escapedInstance.scope.add(operatorAlternative);

        // Escape the input slots.
        for (InputSlot inputSlot : this.requestedInputSlots) {
            final InputSlot escapedInput = alternative.getSlotMapping().resolveUpstream(inputSlot);
            if (escapedInput != null) {
                escapedInstance.requestedInputSlots.add(escapedInput);
            }
        }

        // Escape the output slots.
        for (Tuple<OutputSlot<?>, InputSlot<?>> link : this.servingOutputSlots) {
            if (link.field1 != null) {
                throw new IllegalStateException("Cannot escape a connected output slot.");
            }
            final Collection<OutputSlot<Object>> resolvedOutputSlots =
                    alternative.getSlotMapping().resolveDownstream(link.field0.unchecked());
            for (OutputSlot escapedOutput : resolvedOutputSlots) {
                final List<InputSlot<?>> occupiedInputs = escapedOutput.getOccupiedSlots();
                if (occupiedInputs.isEmpty()) {
                    escapedInstance.servingOutputSlots.add(new Tuple<>(escapedOutput, null));
                } else {
                    for (InputSlot inputSlot : occupiedInputs) {
                        escapedInstance.servingOutputSlots.add(new Tuple<>(escapedOutput, inputSlot));
                    }
                }
            }
        }

        // Escape the PlanImplementation instances.
        for (PlanImplementation planImplementation : this.planImplementations) {
            escapedInstance.planImplementations.add(planImplementation.escape(alternative, escapedInstance));
        }

        return escapedInstance;
    }