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.calcite.rel;
  
  import org.apache.calcite.util.mapping.IntPair;
  
  import com.google.common.collect.ImmutableList;
  
  import java.util.List;
  
  /** RelOptReferentialConstraint base implementation. */
  public class RelReferentialConstraintImpl implements RelReferentialConstraint {
  
    private final List<String> sourceQualifiedName;
    private final List<String> targetQualifiedName;
    private final List<IntPair> columnPairs;
  
    private RelReferentialConstraintImpl(List<String> sourceQualifiedName,
        List<String> targetQualifiedName, List<IntPair> columnPairs) {
      this.sourceQualifiedName = ImmutableList.copyOf(sourceQualifiedName);
      this.targetQualifiedName = ImmutableList.copyOf(targetQualifiedName);
      this.columnPairs = ImmutableList.copyOf(columnPairs);
    }
  
    @Override public List<String> getSourceQualifiedName() {
      return sourceQualifiedName;
    }
  
    @Override public List<String> getTargetQualifiedName() {
      return targetQualifiedName;
    }
  
    @Override public List<IntPair> getColumnPairs() {
      return columnPairs;
    }
  
    public static RelReferentialConstraintImpl of(List<String> sourceQualifiedName,
        List<String> targetQualifiedName, List<IntPair> columnPairs) {
      return new RelReferentialConstraintImpl(
          sourceQualifiedName, targetQualifiedName, columnPairs);
    }
  
    @Override public String toString() {
      return "{ " + sourceQualifiedName + ", " + targetQualifiedName + ", "
          + columnPairs + " }";
    }
  
  }
  