/**
* 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.rule;
import com.foundationdb.sql.optimizer.plan.ColumnExpression;
import com.foundationdb.sql.optimizer.plan.ColumnSource;
import com.foundationdb.sql.optimizer.plan.ExpressionNode;
import com.foundationdb.sql.optimizer.plan.ExpressionVisitor;
import com.foundationdb.sql.optimizer.plan.PlanNode;
import com.foundationdb.sql.optimizer.plan.PlanVisitor;
import java.util.HashSet;
import java.util.Set;
/**
* Finds all the ColumnSources referenced by the given condition expression node
*/
public class ConditionColumnSourcesFinder implements PlanVisitor, ExpressionVisitor {
Set<ColumnSource> referencedSources;
public ConditionColumnSourcesFinder() {
}
public Set<ColumnSource> find(ExpressionNode expression) {
referencedSources = new HashSet<>();
expression.accept(this);
return referencedSources;
}
@Override
public boolean visitEnter(PlanNode n) {
return visit(n);
}
@Override
public boolean visitLeave(PlanNode n) {
return true;
}
@Override
public boolean visit(PlanNode n) {
return true;
}
@Override
public boolean visitEnter(ExpressionNode n) {
return visit(n);
}
@Override
public boolean visitLeave(ExpressionNode n) {
return true;
}
@Override
public boolean visit(ExpressionNode n) {
if (n instanceof ColumnExpression) {
ColumnSource table = ((ColumnExpression)n).getTable();
referencedSources.add(table);
}
return true;
}
}