Package com.google.gerrit.extensions.conditions

Class BooleanCondition

java.lang.Object
com.google.gerrit.extensions.conditions.BooleanCondition
Direct Known Subclasses:
PrivateInternals_BooleanCondition.SubclassOnlyInCoreServer
public abstract class BooleanCondition extends Object
Delayed evaluation of a boolean condition.

  • Field Details

  • Method Details

    • valueOf

      public static BooleanCondition valueOf(boolean a)

    • and

      public static BooleanCondition and(BooleanCondition a, BooleanCondition b)

    • and

      public static BooleanCondition and(boolean a, BooleanCondition b)

    • or

      public static BooleanCondition or(BooleanCondition a, BooleanCondition b)

    • or

      public static BooleanCondition or(boolean a, BooleanCondition b)

    • not

      public static BooleanCondition not(BooleanCondition bc)

    • value

      public abstract boolean value()
      Evaluates the condition and return its value.

    • children

      public abstract <T> Iterable<T> children(Class<T> type)
      Recursively collect all children of type type.
      Parameters:
      type - implementation type of the conditions to collect and return.
      Returns:
      non-null, unmodifiable iteration of children of type type.

    • reduce

      public abstract BooleanCondition reduce()
      Reduce evaluation tree by cutting off branches that evaluate trivially and replacing them with a leave note corresponding to the value the branch evaluated to. 

      
 Example 1 (T=True, F=False, C=non-trivial check):
      OR
     /  \    =>    T
    C   T
 Example 2 (cuts off a not-trivial check):
      AND
     /  \    =>    F
    C   F
 Example 3:
      AND
     /  \    =>    F
    T   F

      There is no guarantee that the resulting tree is minimal. The only guarantee made is that branches that evaluate trivially will be cut off and replaced by primitive values.

    • evaluatesTrivially

      protected abstract boolean evaluatesTrivially()
      Check if the condition evaluates to either true or false without providing additional information to the evaluation tree, e.g. through checks to a remote service such as PermissionBackend.

      In this case, the tree can be reduced to skip all non-trivial checks resulting in a performance gain.