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.asterix.optimizer.rules.util;
  
  import java.util.List;
  
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.commons.lang3.mutable.Mutable;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalPlan;
  import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
  import org.apache.hyracks.algebricks.core.algebra.expressions.UnnestingFunctionCallExpression;
  import org.apache.hyracks.algebricks.core.algebra.operators.logical.SubplanOperator;
  import org.apache.hyracks.algebricks.core.algebra.operators.logical.UnnestOperator;
  
  public class InsertUpsertCheckUtil {
  
      private InsertUpsertCheckUtil() {
      }
  
      /**
       *
       * Checks the query plan rooted at <code>op</code> to see whether there is an invalid returning expression
       * for insert/upsert, i.e., an returning expression that contains dataset accesses.
       *
       * @param op,
       *            the operator in consideration
       * @return true if the returning expression after insert/upsert is invalid; false otherwise.
       */
      public static boolean check(ILogicalOperator op) {
          return checkTopDown(op, false);
      }
  
      // Checks the query plan rooted at <code>op</code> top down to see whether there is an invalid returning expression
      // for insert/upsert, i.e., a returning expression that contains dataset accesses.
      private static boolean checkTopDown(ILogicalOperator op, boolean hasSubplanAboveWithDatasetAccess) {
          boolean metSubplanWithDataScan = hasSubplanAboveWithDatasetAccess;
          if (op.getOperatorTag() == LogicalOperatorTag.SUBPLAN) {
              SubplanOperator subplanOp = (SubplanOperator) op;
              metSubplanWithDataScan = containsDatasetAccess(subplanOp);
          }
          if (op.getOperatorTag() == LogicalOperatorTag.INSERT_DELETE_UPSERT && metSubplanWithDataScan) {
              return true;
          }
          for (Mutable<ILogicalOperator> inputOpRef : op.getInputs()) {
              if (checkTopDown(inputOpRef.getValue(), metSubplanWithDataScan)) {
                  return true;
              }
          }
          return false;
      }
  
      // Checks whether a subplan operator contains a dataset accesses in its nested pipeline.
      private static boolean containsDatasetAccess(SubplanOperator subplanOp) {
          List<ILogicalPlan> nestedPlans = subplanOp.getNestedPlans();
          for (ILogicalPlan nestedPlan : nestedPlans) {
              for (Mutable<ILogicalOperator> opRef : nestedPlan.getRoots()) {
                  if (containsDatasetAccessInternal(opRef.getValue())) {
                      return true;
                  }
              }
          }
          return false;
      }
  
      // Checks whether a query plan rooted at <code>op</code> contains dataset accesses.
      private static boolean containsDatasetAccessInternal(ILogicalOperator op) {
          if (op.getOperatorTag() == LogicalOperatorTag.UNNEST) {
              UnnestOperator unnestOp = (UnnestOperator) op;
              ILogicalExpression unnestExpr = unnestOp.getExpressionRef().getValue();
              UnnestingFunctionCallExpression unnestingFuncExpr = (UnnestingFunctionCallExpression) unnestExpr;
              return unnestingFuncExpr.getFunctionIdentifier().equals(BuiltinFunctions.DATASET);
          }
          if (op.getOperatorTag() == LogicalOperatorTag.SUBPLAN && containsDatasetAccess((SubplanOperator) op)) {
              return true;
          }
          for (Mutable<ILogicalOperator> childRef : op.getInputs()) {
              if (containsDatasetAccessInternal(childRef.getValue())) {
                  return true;
              }
          }
          return false;
      }
  }
  