/*
* 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.jackrabbit.oak.query;
import static com.google.common.collect.ImmutableSet.of;
import static org.apache.jackrabbit.JcrConstants.JCR_SYSTEM;
import static org.apache.jackrabbit.oak.plugins.nodetype.NodeTypeConstants.JCR_NODE_TYPES;
import java.text.ParseException;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.apache.jackrabbit.oak.api.PropertyValue;
import org.apache.jackrabbit.oak.api.QueryEngine;
import org.apache.jackrabbit.oak.api.Result;
import org.apache.jackrabbit.oak.namepath.NamePathMapper;
import org.apache.jackrabbit.oak.query.xpath.XPathToSQL2Converter;
import org.apache.jackrabbit.oak.spi.state.NodeState;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The query engine implementation.
*/
public abstract class QueryEngineImpl implements QueryEngine {
static final String SQL2 = "JCR-SQL2";
static final String SQL = "sql";
static final String XPATH = "xpath";
static final String JQOM = "JCR-JQOM";
static final String NO_LITERALS = "-noLiterals";
static final Logger LOG = LoggerFactory.getLogger(QueryEngineImpl.class);
private static final Set<String> SUPPORTED_LANGUAGES = of(
SQL2, SQL2 + NO_LITERALS,
SQL, SQL + NO_LITERALS,
XPATH, XPATH + NO_LITERALS,
JQOM);
/**
* Whether fallback to the traversing index is supported if no other index
* is available. This is enabled by default and can be disabled for testing
* purposes.
*/
private boolean traversalFallback = true;
/**
* @return Execution context for a single query execution.
*/
protected abstract ExecutionContext getExecutionContext();
@Override
public Set<String> getSupportedQueryLanguages() {
return SUPPORTED_LANGUAGES;
}
/**
* Parse the query (check if it's valid) and get the list of bind variable names.
*
* @param statement
* @param language
* @return the list of bind variable names
* @throws ParseException
*/
@Override
public List<String> getBindVariableNames(String statement, String language, NamePathMapper namePathMapper) throws ParseException {
Query q = parseQuery(statement, language, getExecutionContext(), namePathMapper);
return q.getBindVariableNames();
}
private static Query parseQuery(String statement, String language,
ExecutionContext context, NamePathMapper namePathMapper) throws ParseException {
LOG.debug("Parsing {} statement: {}", language, statement);
NodeState types = context.getBaseState()
.getChildNode(JCR_SYSTEM)
.getChildNode(JCR_NODE_TYPES);
SQL2Parser parser = new SQL2Parser(namePathMapper, types);
if (language.endsWith(NO_LITERALS)) {
language = language.substring(0, language.length() - NO_LITERALS.length());
parser.setAllowNumberLiterals(false);
parser.setAllowTextLiterals(false);
}
if (SQL2.equals(language) || JQOM.equals(language)) {
return parser.parse(statement);
} else if (SQL.equals(language)) {
parser.setSupportSQL1(true);
return parser.parse(statement);
} else if (XPATH.equals(language)) {
XPathToSQL2Converter converter = new XPathToSQL2Converter();
String sql2 = converter.convert(statement);
LOG.debug("XPath > SQL2: {}", sql2);
try {
// OAK-874: No artificial XPath selector name in wildcards
parser.setIncludeSelectorNameInWildcardColumns(false);
return parser.parse(sql2);
} catch (ParseException e) {
ParseException e2 = new ParseException(
statement + " converted to SQL-2 " + e.getMessage(), 0);
e2.initCause(e);
throw e2;
}
} else {
throw new ParseException("Unsupported language: " + language, 0);
}
}
@Override
public Result executeQuery(String statement, String language, long limit,
long offset, Map<String, ? extends PropertyValue> bindings,
NamePathMapper namePathMapper) throws ParseException {
if (limit < 0) {
throw new IllegalArgumentException("Limit may not be negative, is: " + limit);
}
if (offset < 0) {
throw new IllegalArgumentException("Offset may not be negative, is: " + offset);
}
ExecutionContext context = getExecutionContext();
Query q = parseQuery(statement, language, context, namePathMapper);
q.setExecutionContext(context);
q.setNamePathMapper(namePathMapper);
q.setLimit(limit);
q.setOffset(offset);
if (bindings != null) {
for (Entry<String, ? extends PropertyValue> e : bindings.entrySet()) {
q.bindValue(e.getKey(), e.getValue());
}
}
q.setTraversalFallback(traversalFallback);
q.prepare();
return q.executeQuery();
}
protected void setTraversalFallback(boolean traversal) {
this.traversalFallback = traversal;
}
}