Package org.apache.calcite.linq4j.tree

Class ClassDeclarationFinder

  • Direct Known Subclasses:
    DeterministicCodeOptimizer

    public class ClassDeclarationFinder
extends Shuttle
    Entry point for optimizers that factor ou deterministic expressions to final static fields. Instances of this class should not be reused, so new visitor should be created for optimizing a new expression tree.

    • Constructor Detail

      • ClassDeclarationFinder

        protected ClassDeclarationFinder​(ClassDeclarationFinder parent)
        Creates a child optimizer. Typically a child is created for each class declaration, so each optimizer collects fields for exactly one class.
        Parameters:
        parent - parent optimizer

    • Method Detail

      • create

        public static ClassDeclarationFinder create​()
        Creates visitor that uses default optimizer.
        Returns:
        optimizing visitor

      • create

        public static ClassDeclarationFinder create​(Class<? extends ClassDeclarationFinder> optimizingClass)
        Creates visitor that uses given class as optimizer. The implementation should support (ClassDeclarationFinder) constructor.
        Parameters:
        optimizingClass - class that implements optimizations
        Returns:
        optimizing visitor

      • newChildCreator

        private static Function1<ClassDeclarationFinder,ClassDeclarationFinder> newChildCreator​(Class<? extends ClassDeclarationFinder> optimizingClass)
        Creates factory that creates instances of optimizing visitors. The implementation should support (ClassDeclarationFinder) constructor.
        Parameters:
        optimizingClass - class that implements optimizations
        Returns:
        factory that creates instances of given classes

      • preVisit

        public Shuttle preVisit​(NewExpression newExpression)
        Creates optimizer local to the newly generated anonymous class.
        Overrides:
        preVisit in class Shuttle
        Parameters:
        newExpression - expression to optimize
        Returns:
        nested visitor if anonymous class is given

      • preVisit

        public Shuttle preVisit​(ClassDeclaration classDeclaration)
        Creates optimizer local to the newly generated class.
        Overrides:
        preVisit in class Shuttle
        Parameters:
        classDeclaration - expression to optimize
        Returns:
        nested visitor

      • learnFinalStaticDeclarations

        protected void learnFinalStaticDeclarations​(List<MemberDeclaration> memberDeclarations)
        Processes the list of declarations when class expression detected. Sub-classes might figure out the existing fields for reuse.
        Parameters:
        memberDeclarations - list of declarations to process.

      • tryOptimizeNewInstance

        protected Expression tryOptimizeNewInstance​(NewExpression newExpression)
        Optimizes new Type() constructs.
        Parameters:
        newExpression - expression to optimize
        Returns:
        always returns un-optimized expression

      • optimizeDeclarations

        protected List<MemberDeclaration> optimizeDeclarations​(List<MemberDeclaration> memberDeclarations)
        Adds new declarations (e.g. final static fields) to the list of existing ones.
        Parameters:
        memberDeclarations - existing list of declarations
        Returns:
        new list of declarations or the same if no modifications required

      • isConstant

        protected boolean isConstant​(Expression expression)
        Verifies if the expression is effectively constant. This method should be overridden in sub-classes.
        Parameters:
        expression - expression to test
        Returns:
        always returns false

      • isConstant

        protected boolean isConstant​(Iterable<? extends Expression> list)
        Verifies if all the expressions in given list are effectively constant.
        Parameters:
        list - list of expressions to test
        Returns:
        true when all the expressions are known to be constant

      • findDeclaredExpression

        protected ParameterExpression findDeclaredExpression​(Expression expression)
        Finds if there exists ready for reuse declaration for given expression. This method should be overridden in sub-classes.
        Parameters:
        expression - input expression
        Returns:
        always returns null

      • hasField

        protected boolean hasField​(String name)
        Verifies if the variable name is already in use. This method should be overridden in sub-classes.
        Parameters:
        name - name of the variable to test
        Returns:
        always returns false

      • goDeeper

        protected ClassDeclarationFinder goDeeper​()
        Creates child visitor. It is used to traverse nested class declarations.
        Returns:
        new Visitor that is used to optimize class declarations