public LoadEstimate calculate()

in wayang-commons/wayang-core/src/main/java/org/apache/wayang/core/optimizer/costs/IntervalLoadEstimator.java [106:146]
38 lines of code
13 McCabe index (conditional complexity)

    public LoadEstimate calculate(EstimationContext context) {
        final CardinalityEstimate[] inputEstimates = context.getInputCardinalities();
        final CardinalityEstimate[] outputEstimates = context.getOutputCardinalities();
        Validate.isTrue(inputEstimates.length >= this.numInputs || this.numInputs == UNSPECIFIED_NUM_SLOTS,
                "Received %d input estimates, require %d.", inputEstimates.length, this.numInputs);
        Validate.isTrue(outputEstimates.length == this.numOutputs || this.numOutputs == UNSPECIFIED_NUM_SLOTS,
                "Received %d output estimates, require %d.", outputEstimates.length, this.numOutputs);

        long[][] inputEstimateCombinations = this.enumerateCombinations(inputEstimates);
        long[][] outputEstimateCombinations = this.enumerateCombinations(outputEstimates);

        long lowerEstimate = -1, upperEstimate = -1;
        for (int inputEstimateId = 0; inputEstimateId < inputEstimateCombinations.length; inputEstimateId++) {
            for (int outputEstimateId = 0; outputEstimateId < outputEstimateCombinations.length; outputEstimateId++) {
                long estimate = Math.max(this.lowerBoundEstimator.applyAsLong(
                        inputEstimateCombinations[inputEstimateId],
                        outputEstimateCombinations[outputEstimateId]
                ), 0);
                if (lowerEstimate == -1 || estimate < lowerEstimate) {
                    lowerEstimate = estimate;
                }
                if (upperEstimate == -1 || estimate > upperEstimate) {
                    upperEstimate = estimate;
                }
                estimate = Math.max(this.upperBoundEstimator.applyAsLong(
                        inputEstimateCombinations[inputEstimateId],
                        outputEstimateCombinations[outputEstimateId]
                ), 0);
                if (lowerEstimate == -1 || estimate < lowerEstimate) {
                    lowerEstimate = estimate;
                }
                if (upperEstimate == -1 || estimate > upperEstimate) {
                    upperEstimate = estimate;
                }
            }
        }

        double correctnessProbability = this.calculateJointProbability(inputEstimates, outputEstimates)
                * this.correctnessProbablity;
        return new LoadEstimate(lowerEstimate, upperEstimate, correctnessProbability);
    }