/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 org.apache.activemq.apollo.selector;
import org.apache.activemq.apollo.filter.BooleanExpression;
import org.apache.activemq.apollo.filter.ComparisonExpression;
import org.apache.activemq.apollo.filter.FilterException;
import org.apache.activemq.apollo.selector.hyphenated.HyphenatedParser;
import org.apache.activemq.apollo.selector.strict.StrictParser;
import java.io.StringReader;
/**
*/
public class SelectorParser {
private static final LRUCache cache = new LRUCache(100);
private static final String CONVERT_STRING_EXPRESSIONS_PREFIX = "convert_string_expressions:";
private static final String HYPHENATED_PROPS_PREFIX = "hyphenated_props:";
private static final String NO_CONVERT_STRING_EXPRESSIONS_PREFIX = "no_convert_string_expressions:";
private static final String NO_HYPHENATED_PROPS_PREFIX = "no_hyphenated_props:";
public static BooleanExpression parse(String sql) throws FilterException {
Object result = cache.get(sql);
if (result instanceof FilterException) {
throw (FilterException) result;
} else if (result instanceof BooleanExpression) {
return (BooleanExpression) result;
} else {
String actual = sql;
boolean convertStringExpressions = false;
boolean hyphenatedProps=false;
while(true) {
if( actual.startsWith(CONVERT_STRING_EXPRESSIONS_PREFIX)) {
convertStringExpressions = true;
actual = actual.substring(CONVERT_STRING_EXPRESSIONS_PREFIX.length());
continue;
}
if( actual.startsWith(HYPHENATED_PROPS_PREFIX)) {
hyphenatedProps = true;
actual = actual.substring(HYPHENATED_PROPS_PREFIX.length());
continue;
}
if( actual.startsWith(NO_CONVERT_STRING_EXPRESSIONS_PREFIX)) {
convertStringExpressions = false;
actual = actual.substring(NO_CONVERT_STRING_EXPRESSIONS_PREFIX.length());
continue;
}
if( actual.startsWith(NO_HYPHENATED_PROPS_PREFIX)) {
hyphenatedProps = false;
actual = actual.substring(NO_HYPHENATED_PROPS_PREFIX.length());
continue;
}
break;
}
if( convertStringExpressions ) {
ComparisonExpression.CONVERT_STRING_EXPRESSIONS.set(true);
}
try {
BooleanExpression e = null;
if( hyphenatedProps ) {
HyphenatedParser parser = new HyphenatedParser(new StringReader(actual));
e = parser.JmsSelector();
} else {
StrictParser parser = new StrictParser(new StringReader(actual));
e = parser.JmsSelector();
}
cache.put(sql, e);
return e;
} catch (Throwable e) {
FilterException fe = new FilterException(actual, e);
cache.put(sql, fe);
throw fe;
} finally {
if( convertStringExpressions ) {
ComparisonExpression.CONVERT_STRING_EXPRESSIONS.remove();
}
}
}
}
public static void clearCache() {
cache.clear();
}
}