/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.foundationdb.sql.optimizer;
import java.util.List;
import com.foundationdb.qp.operator.QueryBindings;
import com.foundationdb.qp.operator.QueryContext;
import com.foundationdb.qp.operator.UpdateFunction;
import com.foundationdb.qp.row.OverlayingRow;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.rowtype.RowType;
import com.foundationdb.server.types.texpressions.TEvaluatableExpression;
import com.foundationdb.server.types.texpressions.TPreparedExpression;
/** Update a row by substituting expressions for some fields. */
public class ExpressionRowUpdateFunction implements UpdateFunction
{
private final List<TPreparedExpression> pExpressions;
private final RowType rowType;
public ExpressionRowUpdateFunction(List<TPreparedExpression> pExpressions, RowType rowType) {
this.pExpressions = pExpressions;
this.rowType = rowType;
}
/* UpdateFunction */
@Override
public boolean rowIsSelected(Row row) {
return row.rowType().equals(rowType);
}
@Override
public Row evaluate(Row original, QueryContext context, QueryBindings bindings) {
OverlayingRow result = new OverlayingRow(original);
int nfields = rowType.nFields();
for (int i = 0; i < nfields; i++) {
TPreparedExpression expression = pExpressions.get(i);
if (expression != null) {
TEvaluatableExpression evaluation = expression.build();
evaluation.with(original);
evaluation.with(context);
evaluation.with(bindings);
evaluation.evaluate();
result.overlay(i, evaluation.resultValue());
}
}
return result;
}
/* Object */
@Override
public String toString() {
String exprs = pExpressions.toString();
return getClass().getSimpleName() + "(" + exprs + ")";
}
}