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;
  
  import org.apache.commons.lang3.mutable.Mutable;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  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.IOptimizationContext;
  import org.apache.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
  import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.core.algebra.functions.IFunctionInfo;
  import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator;
  import org.apache.hyracks.algebricks.core.algebra.operators.logical.SelectOperator;
  import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
  
  public abstract class AbstractConditionExpressionRule implements IAlgebraicRewriteRule {
      private IOptimizationContext context;
  
      @Override
      public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
              throws AlgebricksException {
          final ILogicalOperator op = opRef.getValue();
          final Mutable<ILogicalExpression> condRef;
          switch (op.getOperatorTag()) {
              case SELECT:
                  final SelectOperator select = (SelectOperator) op;
                  condRef = select.getCondition();
                  break;
              case INNERJOIN:
              case LEFTOUTERJOIN:
                  final AbstractBinaryJoinOperator join = (AbstractBinaryJoinOperator) op;
                  condRef = join.getCondition();
                  break;
              default:
                  return false;
          }
  
          this.context = context;
  
          boolean changed = transform(condRef);
          if (changed) {
              context.computeAndSetTypeEnvironmentForOperator(op);
          }
  
          return changed;
      }
  
      protected final AbstractFunctionCallExpression getFunctionExpression(ILogicalExpression expression) {
          if (expression.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) {
              return null;
          }
  
          return (AbstractFunctionCallExpression) expression;
      }
  
      protected final IFunctionInfo getFunctionInfo(FunctionIdentifier fid) {
          return context.getMetadataProvider().lookupFunction(fid);
      }
  
      /**
       * Transform condition expression
       *
       * @param condRef SELECT or join condition reference
       * @return {@code <code>true</code>} condition has been modified
       * {@code <code>false</code>} otherwise.
       */
      protected abstract boolean transform(Mutable<ILogicalExpression> condRef);
  }
  