/*
* Licensed 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 com.facebook.presto.sql.planner;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.sql.analyzer.Analysis;
import com.facebook.presto.sql.tree.Cast;
import com.facebook.presto.sql.tree.Expression;
import com.facebook.presto.sql.tree.ExpressionRewriter;
import com.facebook.presto.sql.tree.ExpressionTreeRewriter;
import com.facebook.presto.sql.tree.Parameter;
import java.util.List;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;
public class ParameterRewriter
extends ExpressionRewriter<Void>
{
private final List<Expression> parameterValues;
private final Analysis analysis;
public ParameterRewriter(List<Expression> parameterValues)
{
requireNonNull(parameterValues, "parameterValues is null");
this.parameterValues = parameterValues;
this.analysis = null;
}
public ParameterRewriter(List<Expression> parameterValues, Analysis analysis)
{
requireNonNull(parameterValues, "parameterValues is null");
this.parameterValues = parameterValues;
this.analysis = analysis;
}
@Override
public Expression rewriteExpression(Expression node, Void context, ExpressionTreeRewriter<Void> treeRewriter)
{
return treeRewriter.defaultRewrite(node, context);
}
@Override
public Expression rewriteParameter(Parameter node, Void context, ExpressionTreeRewriter<Void> treeRewriter)
{
checkState(parameterValues.size() > node.getPosition(), "Too few parameter values");
return coerceIfNecessary(node, parameterValues.get(node.getPosition()));
}
private Expression coerceIfNecessary(Expression original, Expression rewritten)
{
if (analysis == null) {
return rewritten;
}
Type coercion = analysis.getCoercion(original);
if (coercion != null) {
rewritten = new Cast(
rewritten,
coercion.getTypeSignature().toString(),
false,
analysis.isTypeOnlyCoercion(original));
}
return rewritten;
}
}