Package software.amazon.smithy.rulesengine.logic

Interface ConditionCostModel

public interface ConditionCostModel
Estimates the relative runtime cost of evaluating rule engine conditions.

Costs are relative values where lower numbers indicate cheaper operations. The absolute values don't matter - only their relative ordering affects optimization decisions.

See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    cost(Condition condition)
    Estimates the relative cost of evaluating a condition.
    static ConditionCostModel
    createDefault()
    Creates a default cost model that derives costs from function definitions.
    static ConditionCostModel
    createDefault(int nestedMultiplier)
    Creates a default cost model with a custom multiplier for nested functions.
    static ConditionCostModel
    createUniform()
    Create a cost model that assigns equal cost (1) to all conditions.

  • Method Details

    • createDefault

      static ConditionCostModel createDefault()
      Creates a default cost model that derives costs from function definitions.

      This model uses LibraryFunction.getFunctionDefinition()'s cost and applies a multiplier of 2 for nested function arguments.

      Returns:
      a new default cost model

    • createUniform

      static ConditionCostModel createUniform()
      Create a cost model that assigns equal cost (1) to all conditions.

      Use this when cost-based ordering should be disabled, allowing other factors (CFG structure, cone size, dependencies) to determine condition order exclusively.

      Returns:
      uniform cost model

    • createDefault

      static ConditionCostModel createDefault(int nestedMultiplier)
      Creates a default cost model with a custom multiplier for nested functions.

      The cost of a condition is computed as: 

       cost = baseCost + sum(nestedFunctionCost * nestedMultiplier)

      For example, with a multiplier of 2, the condition isSet(parseUrl(endpoint)) would have cost: 10 + (200 * 2) = 410, reflecting that the expensive parseUrl must be evaluated before the cheap isSet can run.

      Parameters:
      nestedMultiplier - multiplier applied to nested function costs (typically 2-3)
      Returns:
      a new cost model with the specified multiplier

    • cost

      int cost(Condition condition)
      Estimates the relative cost of evaluating a condition.

      Lower values indicate cheaper operations that should be evaluated earlier when BDD structure permits.

      Parameters:
      condition - the condition to evaluate
      Returns:
      relative cost estimate (lower = cheaper)