/**
* Licensed to Odiago, Inc. under one or more contributor license
* agreements. See the NOTICE.txt file distributed with this work for
* additional information regarding copyright ownership. Odiago, Inc.
* 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 com.odiago.flumebase.parser;
import com.odiago.flumebase.plan.PlanContext;
/**
* EXPLAIN statement.
*/
public class ExplainStmt extends SQLStatement {
private SQLStatement mChildStmt;
public ExplainStmt(SQLStatement child) {
mChildStmt = child;
}
public SQLStatement getChildStmt() {
return mChildStmt;
}
public void setChildStmt(SQLStatement child) {
mChildStmt = child;
}
@Override
public void format(StringBuilder sb, int depth) {
pad(sb, depth);
sb.append("EXPLAIN\n");
mChildStmt.format(sb, depth + 1);
}
@Override
public PlanContext createExecPlan(PlanContext planContext) {
// If we're visiting an EXPLAIN statement, then we don't actually
// want to execute a flow specification. So we create it via
// the usual visit sequence, but then we set a flag telling the caller
// to construct a string representation of it rather than execute it.
getChildStmt().createExecPlan(planContext);
StringBuilder sb = planContext.getMsgBuilder();
sb.append("Parse tree:\n");
getChildStmt().format(sb, 0);
sb.append("\n");
PlanContext retContext = new PlanContext(planContext);
retContext.setExplain(true);
return retContext;
}
}