/**
* Copyright 2013-2014 Recruit Technologies Co., Ltd. and contributors
* (see CONTRIBUTORS.md)
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License. A copy of the
* License is distributed with this work in the LICENSE.md file. You may
* also obtain a copy of the License from
*
* 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 org.gennai.gungnir.ql.analysis.analyzer;
import static org.gennai.gungnir.ql.analysis.GungnirLexer.*;
import org.gennai.gungnir.GungnirTopologyException;
import org.gennai.gungnir.Period;
import org.gennai.gungnir.ql.analysis.ASTNode;
import org.gennai.gungnir.ql.analysis.SemanticAnalyzeException;
import org.gennai.gungnir.ql.analysis.SemanticAnalyzer;
import org.gennai.gungnir.ql.stream.GroupedStream;
import org.gennai.gungnir.ql.stream.Stream;
import org.gennai.gungnir.ql.stream.SingleStream;
import org.gennai.gungnir.topology.operator.LimitOperator.LimitType;
import org.gennai.gungnir.topology.operator.limit.LimitInterval;
public class LimitClauseAnalyzer {
private SemanticAnalyzer semanticAnalyzer;
public LimitClauseAnalyzer(SemanticAnalyzer semanticAnalyzer) {
this.semanticAnalyzer = semanticAnalyzer;
}
private Stream limitClauseAnalyze(LimitType type, ASTNode node, Stream stream)
throws SemanticAnalyzeException, GungnirTopologyException {
LimitInterval interval = null;
switch (node.getChild(0).getType()) {
case TOK_COUNT_INTERVAL:
Integer count = semanticAnalyzer.analyzeByAnalyzer(node.getChild(0));
interval = LimitInterval.count(count);
break;
case TOK_TIME_INTERVAL:
Period period = semanticAnalyzer.analyzeByAnalyzer(node.getChild(0));
interval = LimitInterval.time(period);
break;
default:
throw new SemanticAnalyzeException("Invalid limit interval '" + node.getChild(0).getText()
+ "'");
}
if (stream instanceof SingleStream) {
return ((SingleStream) stream).limit(type, interval);
} else {
return ((GroupedStream<?>) stream).limit(type, interval);
}
}
public Stream analyze(ASTNode node, Stream stream)
throws SemanticAnalyzeException, GungnirTopologyException {
Stream s = null;
switch (node.getChild(0).getType()) {
case TOK_FIRST:
s = limitClauseAnalyze(LimitType.FIRST, node.getChild(0), stream);
break;
case TOK_LAST:
s = limitClauseAnalyze(LimitType.LAST, node.getChild(0), stream);
break;
default:
throw new SemanticAnalyzeException("Invalid limit caluse '" + node.getChild(0).getText()
+ "'");
}
Integer parallelism = semanticAnalyzer.analyzeByAnalyzer(node.getChild(1));
if (stream instanceof SingleStream) {
return ((SingleStream) s).parallelism(parallelism);
} else {
return ((GroupedStream<?>) s).parallelism(parallelism);
}
}
}