content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.cassandra.cql3.constraints;
  
  import java.util.List;
  import java.util.Optional;
  
  /**
   * Users implementing this interface and integrating it with SPI (putting JAR on a class path and
   * adding it to META-INF/services/ConstraintProvider) will enrich Cassandra with their custom constraints.
   */
  public interface ConstraintProvider
  {
      /**
       * Tries to instantiate {@link UnaryConstraintFunction} with given arguments.
       * <p>
       * An implementation of this method should always return new object for each method call. Do not
       * cache constraint instances and do not return them! Create a new instance every time. Do not re-use it.
       *
       * @param functionName name of function
       * @param arguments    arguments to the function
       * @return unary constraint function when possible to create with this provider, empty optional otherwise.
       */
      Optional<UnaryConstraintFunction> getUnaryConstraint(String functionName, List<String> arguments);
  
      /**
       * Tries to instantiate {@link ConstraintFunction} with given arguments.
       * <p>
       * An implementation of this method should always return new object for each method call. Do not
       * cache constraint instances and do not return them! Create a new instance every time. Do not re-use it.
       *
       * @param functionName name of function
       * @param arguments    arguments to the function
       * @return constraint function when possible to create with this provider, empty optional otherwise.
       */
      Optional<ConstraintFunction> getConstraintFunction(String functionName, List<String> arguments);
  
      /**
       * @return list of satisfiability checkers for all unary constraints this provider is responsible for
       */
      List<? extends SatisfiabilityChecker> getUnaryConstraintSatisfiabilityCheckers();
  
      /**
       * @return list of satisfiability checkers for all function constraints this provider is responsible for
       */
      List<? extends SatisfiabilityChecker> getConstraintFunctionSatisfiabilityCheckers();
  }
  