/*
* 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.core.query.lucene.join;
import static javax.jcr.query.qom.QueryObjectModelConstants.JCR_JOIN_TYPE_LEFT_OUTER;
import static javax.jcr.query.qom.QueryObjectModelConstants.JCR_JOIN_TYPE_RIGHT_OUTER;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.jcr.UnsupportedRepositoryOperationException;
import javax.jcr.Value;
import javax.jcr.ValueFactory;
import javax.jcr.Workspace;
import javax.jcr.nodetype.NoSuchNodeTypeException;
import javax.jcr.nodetype.NodeType;
import javax.jcr.nodetype.NodeTypeManager;
import javax.jcr.nodetype.PropertyDefinition;
import javax.jcr.query.InvalidQueryException;
import javax.jcr.query.QueryResult;
import javax.jcr.query.Row;
import javax.jcr.query.RowIterator;
import javax.jcr.query.qom.Column;
import javax.jcr.query.qom.Constraint;
import javax.jcr.query.qom.Join;
import javax.jcr.query.qom.Ordering;
import javax.jcr.query.qom.PropertyValue;
import javax.jcr.query.qom.QueryObjectModelConstants;
import javax.jcr.query.qom.QueryObjectModelFactory;
import javax.jcr.query.qom.Selector;
import javax.jcr.query.qom.Source;
import org.apache.commons.io.IOUtils;
import org.apache.jackrabbit.JcrConstants;
import org.apache.jackrabbit.commons.JcrUtils;
import org.apache.jackrabbit.commons.iterator.RowIteratorAdapter;
import org.apache.jackrabbit.commons.query.qom.OperandEvaluator;
import org.apache.jackrabbit.core.query.lucene.LuceneQueryFactory;
import org.apache.jackrabbit.core.query.lucene.sort.DynamicOperandFieldComparatorSource;
import org.apache.jackrabbit.core.query.lucene.sort.RowComparator;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class QueryEngine {
/**
* The logger instance for this class
*/
private static final Logger log = LoggerFactory
.getLogger(QueryEngine.class);
//TODO remove this when the implementation is stable
public static final String NATIVE_SORT_SYSTEM_PROPERTY = "useNativeSort";
private static final boolean NATIVE_SORT = Boolean.valueOf(System
.getProperty(NATIVE_SORT_SYSTEM_PROPERTY, "false"));
private static final int printIndentStep = 4;
private final Session session;
private final LuceneQueryFactory lqf;
private final NodeTypeManager ntManager;
private final QueryObjectModelFactory qomFactory;
private final ValueFactory valueFactory;
private final OperandEvaluator evaluator;
public QueryEngine(Session session, LuceneQueryFactory lqf,
Map<String, Value> variables) throws RepositoryException {
this.session = session;
this.lqf = lqf;
Workspace workspace = session.getWorkspace();
this.ntManager = workspace.getNodeTypeManager();
this.qomFactory = workspace.getQueryManager().getQOMFactory();
this.valueFactory = session.getValueFactory();
this.evaluator = new OperandEvaluator(valueFactory, variables);
}
public QueryResult execute(Column[] columns, Source source,
Constraint constraint, Ordering[] orderings, long offset, long limit)
throws RepositoryException {
long time = System.currentTimeMillis();
QueryResult qr = execute(columns, source, constraint, orderings,
offset, limit, 2);
log.debug("SQL2 QUERY execute took {} ms. native sort is {}.",
System.currentTimeMillis() - time, NATIVE_SORT);
return qr;
}
protected QueryResult execute(Column[] columns, Source source,
Constraint constraint, Ordering[] orderings, long offset,
long limit, int printIndentation) throws RepositoryException {
if (source instanceof Selector) {
return execute(columns, (Selector) source, constraint, orderings,
offset, limit, printIndentation);
}
if (source instanceof Join) {
return execute(columns, (Join) source, constraint, orderings,
offset, limit, printIndentation);
}
throw new UnsupportedRepositoryOperationException(
"Unknown source type: " + source);
}
protected QueryResult execute(Column[] columns, Join join,
Constraint constraint, Ordering[] orderings, long offset,
long limit, int printIndentation) throws RepositoryException {
// Swap the join sources to normalize all outer joins to left
if (JCR_JOIN_TYPE_RIGHT_OUTER.equalsIgnoreCase(join.getJoinType())) {
log.debug(
"{} SQL2 RIGHT OUTER JOIN transformed to LEFT OUTER JOIN.",
genString(printIndentation));
Join betterJoin = qomFactory.join(join.getRight(), join.getLeft(),
JCR_JOIN_TYPE_LEFT_OUTER, join.getJoinCondition());
return execute(columns, betterJoin, constraint, orderings, offset,
limit, printIndentation);
}
JoinMerger merger = JoinMerger.getJoinMerger(join,
getColumnMap(columns, getSelectorNames(join)), evaluator,
qomFactory);
ConstraintSplitter splitter = new ConstraintSplitter(constraint,
qomFactory, merger.getLeftSelectors(),
merger.getRightSelectors(), join);
ConstraintSplitInfo csInfo = splitter.getConstraintSplitInfo();
logQueryAnalysis(csInfo, printIndentation);
boolean isOuterJoin = JCR_JOIN_TYPE_LEFT_OUTER.equalsIgnoreCase(join
.getJoinType());
QueryResult result = execute(merger, csInfo, isOuterJoin,
printIndentation);
long sort = System.currentTimeMillis();
QueryResult sortedResult = sort(result, orderings, evaluator, offset,
limit);
log.debug(" {} SQL2 SORT took {} ms.", genString(printIndentation),
System.currentTimeMillis() - sort);
return sortedResult;
}
protected QueryResult execute(JoinMerger merger,
ConstraintSplitInfo csInfo, boolean isOuterJoin,
int printIndentation) throws RepositoryException {
Comparator<Row> leftCo = new RowPathComparator(
merger.getLeftSelectors());
long timeJoinLeftSide = System.currentTimeMillis();
if (csInfo.isMultiple()) {
log.debug("{} SQL2 JOIN execute: there are multiple inner splits.",
genString(printIndentation));
// first branch
long bTime = System.currentTimeMillis();
QueryResult branch1 = execute(merger,
csInfo.getLeftInnerConstraints(), isOuterJoin,
printIndentation + printIndentStep);
Set<Row> allRows = new TreeSet<Row>(new RowPathComparator(
Arrays.asList(merger.getSelectorNames())));
RowIterator ri1 = branch1.getRows();
while (ri1.hasNext()) {
Row r = ri1.nextRow();
allRows.add(r);
}
log.debug("{} SQL2 JOIN executed first branch, took {} ms.",
genString(printIndentation), System.currentTimeMillis()
- bTime);
// second branch
bTime = System.currentTimeMillis();
QueryResult branch2 = execute(merger,
csInfo.getRightInnerConstraints(), isOuterJoin,
printIndentation + printIndentStep);
RowIterator ri2 = branch2.getRows();
while (ri2.hasNext()) {
Row r = ri2.nextRow();
allRows.add(r);
}
log.debug("{} SQL2 JOIN executed second branch, took {} ms.",
genString(printIndentation), System.currentTimeMillis()
- bTime);
return new SimpleQueryResult(merger.getColumnNames(),
merger.getSelectorNames(), new RowIteratorAdapter(allRows));
}
Set<Row> leftRows = buildLeftRowsJoin(csInfo, leftCo, printIndentation
+ printIndentStep);
if (log.isDebugEnabled()) {
timeJoinLeftSide = System.currentTimeMillis() - timeJoinLeftSide;
log.debug(genString(printIndentation) + "SQL2 JOIN LEFT SIDE took "
+ timeJoinLeftSide + " ms. fetched " + leftRows.size()
+ " rows.");
}
// The join constraint information is split into:
// - rightConstraints selects just the 'ON' constraints
// - csInfo has the 'WHERE' constraints
//
// So, in the case of an OUTER JOIN we'll run 2 queries, one with
// 'ON'
// and one with 'ON' + 'WHERE' conditions
// this way, at merge time in case of an outer join we can tell if
// it's a 'null' row, or a bad row -> one that must not be returned.
// This way at the end we'll have:
// - rightRowsSet containing the 'ON' dataset
// - excludingOuterJoinRowsSet: the 'ON' + 'WHERE' condition
// dataset, or
// NULL if there is no 'WHERE' condition
long timeJoinRightSide = System.currentTimeMillis();
List<Constraint> rightConstraints = merger
.getRightJoinConstraints(leftRows);
Comparator<Row> rightCo = new RowPathComparator(
merger.getRightSelectors());
if (leftRows == null || leftRows.isEmpty()) {
return merger.merge(new RowIteratorAdapter(leftRows),
new RowIteratorAdapter(new TreeSet<Row>()), null, rightCo);
}
Set<Row> rightRows = buildRightRowsJoin(csInfo, rightConstraints,
isOuterJoin, rightCo, printIndentation + printIndentStep);
// this has to be initialized as null
Set<Row> excludingOuterJoinRowsSet = null;
if (isOuterJoin && csInfo.getRightConstraint() != null) {
excludingOuterJoinRowsSet = buildRightRowsJoin(csInfo,
rightConstraints, false, rightCo, printIndentation
+ printIndentStep);
}
if (log.isDebugEnabled()) {
timeJoinRightSide = System.currentTimeMillis() - timeJoinRightSide;
log.debug(genString(printIndentation)
+ "SQL2 JOIN RIGHT SIDE took " + timeJoinRightSide
+ " ms. fetched " + rightRows.size() + " rows.");
}
// merge left with right datasets
return merger.merge(new RowIteratorAdapter(leftRows),
new RowIteratorAdapter(rightRows), excludingOuterJoinRowsSet,
rightCo);
}
private Set<Row> buildLeftRowsJoin(ConstraintSplitInfo csi,
Comparator<Row> comparator, int printIndentation)
throws RepositoryException {
if (csi.isMultiple()) {
if (log.isDebugEnabled()) {
log.debug(genString(printIndentation)
+ "SQL2 JOIN LEFT SIDE there are multiple inner splits.");
}
Set<Row> leftRows = new TreeSet<Row>(comparator);
leftRows.addAll(buildLeftRowsJoin(csi.getLeftInnerConstraints(),
comparator, printIndentation + printIndentStep));
leftRows.addAll(buildLeftRowsJoin(csi.getRightInnerConstraints(),
comparator, printIndentation + printIndentStep));
return leftRows;
}
Set<Row> leftRows = new TreeSet<Row>(comparator);
QueryResult leftResult = execute(null, csi.getSource().getLeft(),
csi.getLeftConstraint(), null, 0, -1, printIndentation);
for (Row row : JcrUtils.getRows(leftResult)) {
leftRows.add(row);
}
return leftRows;
}
/**
* @param csi
* contains 'WHERE' constraints and the source information
* @param rightConstraints
* contains 'ON' constraints
* @param ignoreWhereConstraints
* @param comparator
* used to merge similar rows together
* @param printIndentation
* used in logging
* @return the right-side dataset of the join operation
* @throws RepositoryException
*/
private Set<Row> buildRightRowsJoin(ConstraintSplitInfo csi,
List<Constraint> rightConstraints, boolean ignoreWhereConstraints,
Comparator<Row> comparator, int printIndentation)
throws RepositoryException {
if (csi.isMultiple()) {
if (log.isDebugEnabled()) {
log.debug(genString(printIndentation)
+ "SQL2 JOIN RIGHT SIDE there are multiple inner splits.");
}
Set<Row> rightRows = new TreeSet<Row>(comparator);
rightRows.addAll(buildRightRowsJoin(csi.getLeftInnerConstraints(),
rightConstraints, ignoreWhereConstraints, comparator,
printIndentation + printIndentStep));
rightRows.addAll(buildRightRowsJoin(csi.getRightInnerConstraints(),
rightConstraints, ignoreWhereConstraints, comparator,
printIndentation + printIndentStep));
return rightRows;
}
if (rightConstraints.size() < 500) {
Set<Row> rightRows = new TreeSet<Row>(comparator);
List<Constraint> localRightContraints = rightConstraints;
Constraint rightConstraint = Constraints.and(qomFactory,
Constraints.or(qomFactory, localRightContraints),
csi.getRightConstraint());
if (ignoreWhereConstraints) {
rightConstraint = Constraints.or(qomFactory,
localRightContraints);
}
QueryResult rightResult = execute(null, csi.getSource().getRight(),
rightConstraint, null, 0, -1, printIndentation);
for (Row row : JcrUtils.getRows(rightResult)) {
rightRows.add(row);
}
return rightRows;
}
// the 'batch by 500' approach
Set<Row> rightRows = new TreeSet<Row>(comparator);
for (int i = 0; i < rightConstraints.size(); i += 500) {
if (log.isDebugEnabled()) {
log.debug(genString(printIndentation)
+ "SQL2 JOIN RIGHT SIDE executing batch # " + i + ".");
}
List<Constraint> localRightContraints = rightConstraints.subList(i,
Math.min(i + 500, rightConstraints.size()));
Constraint rightConstraint = Constraints.and(qomFactory,
Constraints.or(qomFactory, localRightContraints),
csi.getRightConstraint());
if (ignoreWhereConstraints) {
rightConstraint = Constraints.or(qomFactory,
localRightContraints);
}
QueryResult rightResult = execute(null, csi.getSource().getRight(),
rightConstraint, null, 0, -1, printIndentation);
for (Row row : JcrUtils.getRows(rightResult)) {
rightRows.add(row);
}
}
return rightRows;
}
private static String genString(int len) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < len; i++) {
sb.append(" ");
}
return sb.toString();
}
private static void logQueryAnalysis(ConstraintSplitInfo csi,
int printIndentation) throws RepositoryException {
if (!log.isDebugEnabled()) {
return;
}
StringBuilder sb = new StringBuilder();
sb.append(genString(printIndentation));
sb.append("SQL2 JOIN analysis:");
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(constraintSplitInfoToString(csi, 2));
log.debug(sb.toString());
}
private static String constraintSplitInfoToString(ConstraintSplitInfo csi,
int printIndentation) throws RepositoryException {
if (csi.isMultiple()) {
StringBuilder sb = new StringBuilder();
sb.append(genString(printIndentation));
sb.append("SQL2 JOIN inner split -> ");
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(genString(printIndentation));
sb.append("+");
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(constraintSplitInfoToString(
csi.getLeftInnerConstraints(), printIndentation
+ printIndentStep));
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(genString(printIndentation));
sb.append("+");
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(constraintSplitInfoToString(
csi.getRightInnerConstraints(), printIndentation
+ printIndentStep));
return sb.toString();
}
StringBuilder sb = new StringBuilder();
sb.append(genString(printIndentation));
sb.append("SQL2 JOIN source: ");
sb.append(csi.getSource());
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(genString(printIndentation));
sb.append("SQL2 JOIN left constraint: ");
sb.append(csi.getLeftConstraint());
sb.append(IOUtils.LINE_SEPARATOR);
sb.append(genString(printIndentation));
sb.append("SQL2 JOIN right constraint: ");
sb.append(csi.getRightConstraint());
return sb.toString();
}
protected QueryResult execute(Column[] columns, Selector selector,
Constraint constraint, Ordering[] orderings, long offset,
long limit, int printIndentation) throws RepositoryException {
long time = System.currentTimeMillis();
Map<String, NodeType> selectorMap = getSelectorNames(selector);
String[] selectorNames = selectorMap.keySet().toArray(
new String[selectorMap.size()]);
Map<String, PropertyValue> columnMap = getColumnMap(columns,
selectorMap);
String[] columnNames = columnMap.keySet().toArray(
new String[columnMap.size()]);
Sort sort = new Sort();
if (NATIVE_SORT) {
sort = new Sort(createSortFields(orderings, session));
}
// if true it means that the LuceneQueryFactory should just let the
// QueryEngine take care of sorting and applying offset and limit
// constraints
boolean externalSort = !NATIVE_SORT;
RowIterator rows = null;
try {
rows = new RowIteratorAdapter(lqf.execute(columnMap, selector,
constraint, sort, externalSort, offset, limit));
} catch (IOException e) {
throw new RepositoryException("Failed to access the query index", e);
} finally {
log.debug(
"{}SQL2 SELECT took {} ms. selector: {}, columns: {}, constraint: {}, offset {}, limit {}",
new Object[] { genString(printIndentation),
System.currentTimeMillis() - time, selector,
Arrays.toString(columnNames), constraint, offset,
limit });
}
QueryResult result = new SimpleQueryResult(columnNames, selectorNames,
rows);
if (NATIVE_SORT) {
return result;
}
long timeSort = System.currentTimeMillis();
QueryResult sorted = sort(result, orderings, evaluator, offset, limit);
log.debug("{}SQL2 SORT took {} ms.", genString(printIndentation),
System.currentTimeMillis() - timeSort);
return sorted;
}
public SortField[] createSortFields(Ordering[] orderings, Session session)
throws RepositoryException {
if (orderings == null || orderings.length == 0) {
return new SortField[] { SortField.FIELD_SCORE };
}
// orderings[] -> (property, ordering)
Map<String, Ordering> orderByProperties = new HashMap<String, Ordering>();
for (Ordering o : orderings) {
final String p = o.toString();
if (!orderByProperties.containsKey(p)) {
orderByProperties.put(p, o);
}
}
final DynamicOperandFieldComparatorSource dofcs = new DynamicOperandFieldComparatorSource(
session, evaluator, orderByProperties);
List<SortField> sortFields = new ArrayList<SortField>();
// as it turn out, orderByProperties.keySet() doesn't keep the original
// insertion order
for (Ordering o : orderings) {
final String p = o.toString();
// order on jcr:score does not use the natural order as
// implemented in lucene. score ascending in lucene means that
// higher scores are first. JCR specs that lower score values
// are first.
boolean isAsc = QueryObjectModelConstants.JCR_ORDER_ASCENDING
.equals(o.getOrder());
if (JcrConstants.JCR_SCORE.equals(p)) {
sortFields.add(new SortField(null, SortField.SCORE, !isAsc));
} else {
// TODO use native sort if available
sortFields.add(new SortField(p, dofcs, !isAsc));
}
}
return sortFields.toArray(new SortField[sortFields.size()]);
}
private Map<String, PropertyValue> getColumnMap(Column[] columns,
Map<String, NodeType> selectors) throws RepositoryException {
Map<String, PropertyValue> map = new LinkedHashMap<String, PropertyValue>();
if (columns != null && columns.length > 0) {
for (int i = 0; i < columns.length; i++) {
String name = columns[i].getColumnName();
if (name != null) {
map.put(name,
qomFactory.propertyValue(
columns[i].getSelectorName(),
columns[i].getPropertyName()));
} else {
String selector = columns[i].getSelectorName();
map.putAll(getColumnMap(selector, selectors.get(selector)));
}
}
} else {
for (Map.Entry<String, NodeType> selector : selectors.entrySet()) {
map.putAll(getColumnMap(selector.getKey(), selector.getValue()));
}
}
return map;
}
private Map<String, PropertyValue> getColumnMap(String selector,
NodeType type) throws RepositoryException {
Map<String, PropertyValue> map = new LinkedHashMap<String, PropertyValue>();
for (PropertyDefinition definition : type.getPropertyDefinitions()) {
String name = definition.getName();
if (!definition.isMultiple() && !"*".equals(name)) {
// TODO: Add proper quoting
map.put(selector + "." + name,
qomFactory.propertyValue(selector, name));
}
}
return map;
}
private Map<String, NodeType> getSelectorNames(Source source)
throws RepositoryException {
if (source instanceof Selector) {
Selector selector = (Selector) source;
return Collections.singletonMap(selector.getSelectorName(),
getNodeType(selector));
} else if (source instanceof Join) {
Join join = (Join) source;
Map<String, NodeType> map = new LinkedHashMap<String, NodeType>();
map.putAll(getSelectorNames(join.getLeft()));
map.putAll(getSelectorNames(join.getRight()));
return map;
} else {
throw new UnsupportedRepositoryOperationException(
"Unknown source type: " + source);
}
}
private NodeType getNodeType(Selector selector) throws RepositoryException {
try {
return ntManager.getNodeType(selector.getNodeTypeName());
} catch (NoSuchNodeTypeException e) {
throw new InvalidQueryException(
"Selected node type does not exist: " + selector, e);
}
}
/**
* Sorts the given query results according to the given QOM orderings. If
* one or more orderings have been specified, this method will iterate
* through the entire original result set, order the collected rows, and
* return a new result set based on the sorted collection of rows.
*
* @param result
* original query results
* @param orderings
* QOM orderings
* @param offset
* result offset
* @param limit
* result limit
* @return sorted query results
* @throws RepositoryException
* if the results can not be sorted
*/
protected static QueryResult sort(QueryResult result,
final Ordering[] orderings, OperandEvaluator evaluator,
long offset, long limit) throws RepositoryException {
if ((orderings != null && orderings.length > 0) || offset != 0
|| limit >= 0) {
List<Row> rows = new ArrayList<Row>();
RowIterator iterator = result.getRows();
while (iterator.hasNext()) {
rows.add(iterator.nextRow());
}
if (orderings != null && orderings.length > 0) {
Collections.sort(rows, new RowComparator(orderings, evaluator));
}
if (offset > 0) {
int size = rows.size();
rows = rows.subList((int) Math.min(offset, size), size);
}
if (limit >= 0) {
int size = rows.size();
rows = rows.subList(0, (int) Math.min(limit, size));
}
return new SimpleQueryResult(result.getColumnNames(),
result.getSelectorNames(), new RowIteratorAdapter(rows));
} else {
return result;
}
}
}