feat: hint from comment (#141)

Author: KirillKurdyukov

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/YdbDialect.java

@@ -12,6 +12,7 @@
 import org.hibernate.mapping.Constraint;
 import org.hibernate.mapping.ForeignKey;
 import org.hibernate.mapping.Index;
+import org.hibernate.query.spi.QueryOptions;
 import org.hibernate.service.ServiceRegistry;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
 import org.hibernate.sql.ast.spi.SqlAppender;
@@ -121,8 +122,20 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
     }
 
     @Override
-    public String getQueryHintString(String query, List<String> hintList) {
-        return IndexQueryHintHandler.INSTANCE.addQueryHints(query, hintList);
+    public String addSqlHintOrComment(String sql, QueryOptions queryOptions, boolean commentsEnabled) {
+        if (queryOptions.getDatabaseHints() != null) {
+            sql = IndexQueryHintHandler.addQueryHints(sql, queryOptions.getDatabaseHints());
+        }
+
+        if (queryOptions.getComment() != null && IndexQueryHintHandler.commentIsHint(queryOptions.getComment())) {
+            return IndexQueryHintHandler.addQueryHints(sql, List.of(queryOptions.getComment()));
+        }
+
+        if (commentsEnabled && queryOptions.getComment() != null) {
+            sql = prependComment(sql, queryOptions.getComment());
+        }
+
+        return sql;
     }
 
     @Override

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/hint/IndexQueryHintHandler.java

@@ -13,9 +13,12 @@ public class IndexQueryHintHandler {
             .compile("^\\s*(select.+?from\\s+\\w+)(.+where.+)$", Pattern.CASE_INSENSITIVE);
 
     public static final String HINT_USE_INDEX = "use_index:";
-    public static final IndexQueryHintHandler INSTANCE = new IndexQueryHintHandler();
 
-    public String addQueryHints(String query, List<String> hints) {
+    public static boolean commentIsHint(String comment) {
+        return comment.startsWith(HINT_USE_INDEX);
+    }
+
+    public static String addQueryHints(String query, List<String> hints) {
         if (hints.isEmpty()) {
             return query;
         }

hibernate-dialect/src/test/java/tech/ydb/hibernate/student/StudentsRepositoryTest.java

@@ -3,6 +3,7 @@
 import java.util.List;
 import org.hibernate.cfg.AvailableSettings;
 import org.hibernate.cfg.Configuration;
+import org.hibernate.jpa.HibernateHints;
 import org.hibernate.query.Query;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.BeforeAll;
@@ -165,7 +166,18 @@ void groupByGroupName_ViewIndex() {
                 session -> {
                     Group group = session
                             .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
-                            .addQueryHint("use_index:group_name_index")
+                            .addQueryHint("use_index:group_name_index") // Hibernate
+                            .getSingleResult();
+
+                    assertEquals("M3439", group.getName());
+                }
+        );
+
+        inTransaction(
+                session -> {
+                    Group group = session
+                            .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
+                            .setHint(HibernateHints.HINT_COMMENT, "use_index:group_name_index") // JPA
                             .getSingleResult();
 
                     assertEquals("M3439", group.getName());