query_optimizer/rules/UpdateExpression.cpp

/**
 * 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.
 **/

#include "query_optimizer/rules/UpdateExpression.hpp"

#include <unordered_map>

#include "query_optimizer/expressions/Expression.hpp"
#include "query_optimizer/expressions/ExprId.hpp"
#include "query_optimizer/expressions/NamedExpression.hpp"
#include "query_optimizer/expressions/PatternMatcher.hpp"
#include "query_optimizer/rules/Rule.hpp"

#include "glog/logging.h"

namespace quickstep {
namespace optimizer {

namespace E = ::quickstep::optimizer::expressions;

E::ExpressionPtr UpdateExpression::applyToNode(const E::ExpressionPtr &input) {
  E::NamedExpressionPtr named_expression;

  if (E::SomeNamedExpression::MatchesWithConditionalCast(input, &named_expression)) {
    const std::unordered_map<E::ExprId, E::ExpressionPtr>::const_iterator it =
        substitution_map_.find(named_expression->id());
    if (it != substitution_map_.end()) {
      LOG_APPLYING_RULE(input, (it->second));
      return it->second;
    }
  }

  LOG_IGNORING_RULE(input);
  return input;
}

}  // namespace optimizer
}  // namespace quickstep