/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.hql.internal.ast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import antlr.ANTLRException;
import antlr.RecognitionException;
import antlr.TokenStreamException;
import antlr.collections.AST;
import org.jboss.logging.Logger;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.QueryParameters;
import org.hibernate.engine.spi.RowSelection;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.hql.internal.QueryExecutionRequestException;
import org.hibernate.hql.spi.ParameterTranslations;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.MappingException;
import org.hibernate.QueryException;
import org.hibernate.ScrollableResults;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.event.spi.EventSource;
import org.hibernate.hql.spi.FilterTranslator;
import org.hibernate.hql.internal.antlr.HqlSqlTokenTypes;
import org.hibernate.hql.internal.antlr.HqlTokenTypes;
import org.hibernate.hql.internal.antlr.SqlTokenTypes;
import org.hibernate.hql.internal.ast.exec.BasicExecutor;
import org.hibernate.hql.internal.ast.exec.MultiTableDeleteExecutor;
import org.hibernate.hql.internal.ast.exec.MultiTableUpdateExecutor;
import org.hibernate.hql.internal.ast.exec.StatementExecutor;
import org.hibernate.hql.internal.ast.tree.AggregatedSelectExpression;
import org.hibernate.hql.internal.ast.tree.FromElement;
import org.hibernate.hql.internal.ast.tree.InsertStatement;
import org.hibernate.hql.internal.ast.tree.QueryNode;
import org.hibernate.hql.internal.ast.tree.Statement;
import org.hibernate.hql.internal.ast.util.ASTPrinter;
import org.hibernate.hql.internal.ast.util.ASTUtil;
import org.hibernate.hql.internal.ast.util.NodeTraverser;
import org.hibernate.internal.util.ReflectHelper;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.internal.util.collections.IdentitySet;
import org.hibernate.loader.hql.QueryLoader;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.type.Type;
/**
* A QueryTranslator that uses an Antlr-based parser.
*
* @author Joshua Davis (pgmjsd@sourceforge.net)
*/
public class QueryTranslatorImpl implements FilterTranslator {
private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, QueryTranslatorImpl.class.getName());
private SessionFactoryImplementor factory;
private final String queryIdentifier;
private String hql;
private boolean shallowQuery;
private Map tokenReplacements;
private Map enabledFilters; //TODO:this is only needed during compilation .. can we eliminate the instvar?
private boolean compiled;
private QueryLoader queryLoader;
private StatementExecutor statementExecutor;
private Statement sqlAst;
private String sql;
private ParameterTranslations paramTranslations;
private List collectedParameterSpecifications;
/**
* Creates a new AST-based query translator.
*
* @param queryIdentifier The query-identifier (used in stats collection)
* @param query The hql query to translate
* @param enabledFilters Currently enabled filters
* @param factory The session factory constructing this translator instance.
*/
public QueryTranslatorImpl(
String queryIdentifier,
String query,
Map enabledFilters,
SessionFactoryImplementor factory) {
this.queryIdentifier = queryIdentifier;
this.hql = query;
this.compiled = false;
this.shallowQuery = false;
this.enabledFilters = enabledFilters;
this.factory = factory;
}
/**
* Compile a "normal" query. This method may be called multiple
* times. Subsequent invocations are no-ops.
*
* @param replacements Defined query substitutions.
* @param shallow Does this represent a shallow (scalar or entity-id) select?
* @throws QueryException There was a problem parsing the query string.
* @throws MappingException There was a problem querying defined mappings.
*/
public void compile(
Map replacements,
boolean shallow) throws QueryException, MappingException {
doCompile( replacements, shallow, null );
}
/**
* Compile a filter. This method may be called multiple
* times. Subsequent invocations are no-ops.
*
* @param collectionRole the role name of the collection used as the basis for the filter.
* @param replacements Defined query substitutions.
* @param shallow Does this represent a shallow (scalar or entity-id) select?
* @throws QueryException There was a problem parsing the query string.
* @throws MappingException There was a problem querying defined mappings.
*/
public void compile(
String collectionRole,
Map replacements,
boolean shallow) throws QueryException, MappingException {
doCompile( replacements, shallow, collectionRole );
}
/**
* Performs both filter and non-filter compiling.
*
* @param replacements Defined query substitutions.
* @param shallow Does this represent a shallow (scalar or entity-id) select?
* @param collectionRole the role name of the collection used as the basis for the filter, NULL if this
* is not a filter.
*/
private synchronized void doCompile(Map replacements, boolean shallow, String collectionRole) {
// If the query is already compiled, skip the compilation.
if ( compiled ) {
LOG.debugf("compile() : The query is already compiled, skipping...");
return;
}
// Remember the parameters for the compilation.
this.tokenReplacements = replacements;
if ( tokenReplacements == null ) {
tokenReplacements = new HashMap();
}
this.shallowQuery = shallow;
try {
// PHASE 1 : Parse the HQL into an AST.
HqlParser parser = parse( true );
// PHASE 2 : Analyze the HQL AST, and produce an SQL AST.
HqlSqlWalker w = analyze( parser, collectionRole );
sqlAst = ( Statement ) w.getAST();
// at some point the generate phase needs to be moved out of here,
// because a single object-level DML might spawn multiple SQL DML
// command executions.
//
// Possible to just move the sql generation for dml stuff, but for
// consistency-sake probably best to just move responsiblity for
// the generation phase completely into the delegates
// (QueryLoader/StatementExecutor) themselves. Also, not sure why
// QueryLoader currently even has a dependency on this at all; does
// it need it? Ideally like to see the walker itself given to the delegates directly...
if ( sqlAst.needsExecutor() ) {
statementExecutor = buildAppropriateStatementExecutor( w );
}
else {
// PHASE 3 : Generate the SQL.
generate( ( QueryNode ) sqlAst );
queryLoader = new QueryLoader( this, factory, w.getSelectClause() );
}
compiled = true;
}
catch ( QueryException qe ) {
qe.setQueryString( hql );
throw qe;
}
catch ( RecognitionException e ) {
// we do not actually propagate ANTLRExceptions as a cause, so
// log it here for diagnostic purposes
LOG.trace("Converted antlr.RecognitionException", e);
throw QuerySyntaxException.convert( e, hql );
}
catch ( ANTLRException e ) {
// we do not actually propagate ANTLRExceptions as a cause, so
// log it here for diagnostic purposes
LOG.trace("Converted antlr.ANTLRException", e);
throw new QueryException( e.getMessage(), hql );
}
this.enabledFilters = null; //only needed during compilation phase...
}
private void generate(AST sqlAst) throws QueryException, RecognitionException {
if ( sql == null ) {
SqlGenerator gen = new SqlGenerator(factory);
gen.statement( sqlAst );
sql = gen.getSQL();
if (LOG.isDebugEnabled()) {
LOG.debugf("HQL: %s", hql);
LOG.debugf("SQL: %s", sql);
}
gen.getParseErrorHandler().throwQueryException();
collectedParameterSpecifications = gen.getCollectedParameters();
}
}
private HqlSqlWalker analyze(HqlParser parser, String collectionRole) throws QueryException, RecognitionException {
HqlSqlWalker w = new HqlSqlWalker( this, factory, parser, tokenReplacements, collectionRole );
AST hqlAst = parser.getAST();
// Transform the tree.
w.statement( hqlAst );
if (LOG.isDebugEnabled()) {
ASTPrinter printer = new ASTPrinter( SqlTokenTypes.class );
LOG.debug( printer.showAsString( w.getAST(), "--- SQL AST ---" ) );
}
w.getParseErrorHandler().throwQueryException();
return w;
}
private HqlParser parse(boolean filter) throws TokenStreamException, RecognitionException {
// Parse the query string into an HQL AST.
HqlParser parser = HqlParser.getInstance( hql );
parser.setFilter( filter );
LOG.debugf("parse() - HQL: %s", hql);
parser.statement();
AST hqlAst = parser.getAST();
JavaConstantConverter converter = new JavaConstantConverter();
NodeTraverser walker = new NodeTraverser( converter );
walker.traverseDepthFirst( hqlAst );
showHqlAst( hqlAst );
parser.getParseErrorHandler().throwQueryException();
return parser;
}
void showHqlAst(AST hqlAst) {
if (LOG.isDebugEnabled()) {
ASTPrinter printer = new ASTPrinter( HqlTokenTypes.class );
LOG.debug( printer.showAsString( hqlAst, "--- HQL AST ---" ) );
}
}
private void errorIfDML() throws HibernateException {
if ( sqlAst.needsExecutor() ) {
throw new QueryExecutionRequestException( "Not supported for DML operations", hql );
}
}
private void errorIfSelect() throws HibernateException {
if ( !sqlAst.needsExecutor() ) {
throw new QueryExecutionRequestException( "Not supported for select queries", hql );
}
}
public String getQueryIdentifier() {
return queryIdentifier;
}
public Statement getSqlAST() {
return sqlAst;
}
private HqlSqlWalker getWalker() {
return sqlAst.getWalker();
}
/**
* Types of the return values of an <tt>iterate()</tt> style query.
*
* @return an array of <tt>Type</tt>s.
*/
public Type[] getReturnTypes() {
errorIfDML();
return getWalker().getReturnTypes();
}
public String[] getReturnAliases() {
errorIfDML();
return getWalker().getReturnAliases();
}
public String[][] getColumnNames() {
errorIfDML();
return getWalker().getSelectClause().getColumnNames();
}
public Set getQuerySpaces() {
return getWalker().getQuerySpaces();
}
public List list(SessionImplementor session, QueryParameters queryParameters)
throws HibernateException {
// Delegate to the QueryLoader...
errorIfDML();
QueryNode query = ( QueryNode ) sqlAst;
boolean hasLimit = queryParameters.getRowSelection() != null && queryParameters.getRowSelection().definesLimits();
boolean needsDistincting = ( query.getSelectClause().isDistinct() || hasLimit ) && containsCollectionFetches();
QueryParameters queryParametersToUse;
if ( hasLimit && containsCollectionFetches() ) {
LOG.firstOrMaxResultsSpecifiedWithCollectionFetch();
RowSelection selection = new RowSelection();
selection.setFetchSize( queryParameters.getRowSelection().getFetchSize() );
selection.setTimeout( queryParameters.getRowSelection().getTimeout() );
queryParametersToUse = queryParameters.createCopyUsing( selection );
}
else {
queryParametersToUse = queryParameters;
}
List results = queryLoader.list( session, queryParametersToUse );
if ( needsDistincting ) {
int includedCount = -1;
// NOTE : firstRow is zero-based
int first = !hasLimit || queryParameters.getRowSelection().getFirstRow() == null
? 0
: queryParameters.getRowSelection().getFirstRow().intValue();
int max = !hasLimit || queryParameters.getRowSelection().getMaxRows() == null
? -1
: queryParameters.getRowSelection().getMaxRows().intValue();
int size = results.size();
List tmp = new ArrayList();
IdentitySet distinction = new IdentitySet();
for ( int i = 0; i < size; i++ ) {
final Object result = results.get( i );
if ( !distinction.add( result ) ) {
continue;
}
includedCount++;
if ( includedCount < first ) {
continue;
}
tmp.add( result );
// NOTE : ( max - 1 ) because first is zero-based while max is not...
if ( max >= 0 && ( includedCount - first ) >= ( max - 1 ) ) {
break;
}
}
results = tmp;
}
return results;
}
/**
* Return the query results as an iterator
*/
public Iterator iterate(QueryParameters queryParameters, EventSource session)
throws HibernateException {
// Delegate to the QueryLoader...
errorIfDML();
return queryLoader.iterate( queryParameters, session );
}
/**
* Return the query results, as an instance of <tt>ScrollableResults</tt>
*/
public ScrollableResults scroll(QueryParameters queryParameters, SessionImplementor session)
throws HibernateException {
// Delegate to the QueryLoader...
errorIfDML();
return queryLoader.scroll( queryParameters, session );
}
public int executeUpdate(QueryParameters queryParameters, SessionImplementor session)
throws HibernateException {
errorIfSelect();
return statementExecutor.execute( queryParameters, session );
}
/**
* The SQL query string to be called; implemented by all subclasses
*/
public String getSQLString() {
return sql;
}
public List collectSqlStrings() {
ArrayList list = new ArrayList();
if ( isManipulationStatement() ) {
String[] sqlStatements = statementExecutor.getSqlStatements();
for ( int i = 0; i < sqlStatements.length; i++ ) {
list.add( sqlStatements[i] );
}
}
else {
list.add( sql );
}
return list;
}
// -- Package local methods for the QueryLoader delegate --
public boolean isShallowQuery() {
return shallowQuery;
}
public String getQueryString() {
return hql;
}
public Map getEnabledFilters() {
return enabledFilters;
}
public int[] getNamedParameterLocs(String name) {
return getWalker().getNamedParameterLocations( name );
}
public boolean containsCollectionFetches() {
errorIfDML();
List collectionFetches = ( ( QueryNode ) sqlAst ).getFromClause().getCollectionFetches();
return collectionFetches != null && collectionFetches.size() > 0;
}
public boolean isManipulationStatement() {
return sqlAst.needsExecutor();
}
public void validateScrollability() throws HibernateException {
// Impl Note: allows multiple collection fetches as long as the
// entire fecthed graph still "points back" to a single
// root entity for return
errorIfDML();
QueryNode query = ( QueryNode ) sqlAst;
// If there are no collection fetches, then no further checks are needed
List collectionFetches = query.getFromClause().getCollectionFetches();
if ( collectionFetches.isEmpty() ) {
return;
}
// A shallow query is ok (although technically there should be no fetching here...)
if ( isShallowQuery() ) {
return;
}
// Otherwise, we have a non-scalar select with defined collection fetch(es).
// Make sure that there is only a single root entity in the return (no tuples)
if ( getReturnTypes().length > 1 ) {
throw new HibernateException( "cannot scroll with collection fetches and returned tuples" );
}
FromElement owner = null;
Iterator itr = query.getSelectClause().getFromElementsForLoad().iterator();
while ( itr.hasNext() ) {
// should be the first, but just to be safe...
final FromElement fromElement = ( FromElement ) itr.next();
if ( fromElement.getOrigin() == null ) {
owner = fromElement;
break;
}
}
if ( owner == null ) {
throw new HibernateException( "unable to locate collection fetch(es) owner for scrollability checks" );
}
// This is not strictly true. We actually just need to make sure that
// it is ordered by root-entity PK and that that order-by comes before
// any non-root-entity ordering...
AST primaryOrdering = query.getOrderByClause().getFirstChild();
if ( primaryOrdering != null ) {
// TODO : this is a bit dodgy, come up with a better way to check this (plus see above comment)
String [] idColNames = owner.getQueryable().getIdentifierColumnNames();
String expectedPrimaryOrderSeq = StringHelper.join(
", ",
StringHelper.qualify( owner.getTableAlias(), idColNames )
);
if ( !primaryOrdering.getText().startsWith( expectedPrimaryOrderSeq ) ) {
throw new HibernateException( "cannot scroll results with collection fetches which are not ordered primarily by the root entity's PK" );
}
}
}
private StatementExecutor buildAppropriateStatementExecutor(HqlSqlWalker walker) {
Statement statement = ( Statement ) walker.getAST();
if ( walker.getStatementType() == HqlSqlTokenTypes.DELETE ) {
FromElement fromElement = walker.getFinalFromClause().getFromElement();
Queryable persister = fromElement.getQueryable();
if ( persister.isMultiTable() ) {
return new MultiTableDeleteExecutor( walker );
}
else {
return new BasicExecutor( walker, persister );
}
}
else if ( walker.getStatementType() == HqlSqlTokenTypes.UPDATE ) {
FromElement fromElement = walker.getFinalFromClause().getFromElement();
Queryable persister = fromElement.getQueryable();
if ( persister.isMultiTable() ) {
// even here, if only properties mapped to the "base table" are referenced
// in the set and where clauses, this could be handled by the BasicDelegate.
// TODO : decide if it is better performance-wise to doAfterTransactionCompletion that check, or to simply use the MultiTableUpdateDelegate
return new MultiTableUpdateExecutor( walker );
}
else {
return new BasicExecutor( walker, persister );
}
}
else if ( walker.getStatementType() == HqlSqlTokenTypes.INSERT ) {
return new BasicExecutor( walker, ( ( InsertStatement ) statement ).getIntoClause().getQueryable() );
}
else {
throw new QueryException( "Unexpected statement type" );
}
}
public ParameterTranslations getParameterTranslations() {
if ( paramTranslations == null ) {
paramTranslations = new ParameterTranslationsImpl( getWalker().getParameters() );
// paramTranslations = new ParameterTranslationsImpl( collectedParameterSpecifications );
}
return paramTranslations;
}
public List getCollectedParameterSpecifications() {
return collectedParameterSpecifications;
}
@Override
public Class getDynamicInstantiationResultType() {
AggregatedSelectExpression aggregation = queryLoader.getAggregatedSelectExpression();
return aggregation == null ? null : aggregation.getAggregationResultType();
}
public static class JavaConstantConverter implements NodeTraverser.VisitationStrategy {
private AST dotRoot;
public void visit(AST node) {
if ( dotRoot != null ) {
// we are already processing a dot-structure
if (ASTUtil.isSubtreeChild(dotRoot, node)) return;
// we are now at a new tree level
dotRoot = null;
}
if ( dotRoot == null && node.getType() == HqlTokenTypes.DOT ) {
dotRoot = node;
handleDotStructure( dotRoot );
}
}
private void handleDotStructure(AST dotStructureRoot) {
String expression = ASTUtil.getPathText( dotStructureRoot );
Object constant = ReflectHelper.getConstantValue( expression );
if ( constant != null ) {
dotStructureRoot.setFirstChild( null );
dotStructureRoot.setType( HqlTokenTypes.JAVA_CONSTANT );
dotStructureRoot.setText( expression );
}
}
}
}