feat: use_index hint

Author: KirillKurdyukov

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

@@ -1,8 +1,7 @@
 package tech.ydb.hibernate.dialect;
 
 import java.time.LocalDateTime;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
+import java.util.List;
 import org.hibernate.boot.model.FunctionContributions;
 import org.hibernate.boot.model.TypeContributions;
 import org.hibernate.dialect.Dialect;
@@ -53,6 +52,7 @@
 import org.hibernate.type.StandardBasicTypes;
 import tech.ydb.hibernate.dialect.exporter.EmptyExporter;
 import tech.ydb.hibernate.dialect.exporter.YdbIndexExporter;
+import tech.ydb.hibernate.dialect.hint.IndexQueryHintHandler;
 import tech.ydb.hibernate.dialect.translator.YdbSqlAstTranslatorFactory;
 import tech.ydb.hibernate.dialect.types.LocalDateTimeJavaType;
 import tech.ydb.hibernate.dialect.types.LocalDateTimeJdbcType;
@@ -64,8 +64,6 @@ public class YdbDialect extends Dialect {
 
     private static final Exporter<ForeignKey> FOREIGN_KEY_EMPTY_EXPORTER = new EmptyExporter<>();
     private static final Exporter<Constraint> UNIQUE_KEY_EMPTY_EXPORTER = new EmptyExporter<>();
-    private static final Pattern SELECT_FROM_WHERE_QUERY_PATTERN = Pattern
-            .compile("^\\s*(select.+?from\\s+\\w+)(.+where.+)$", Pattern.CASE_INSENSITIVE);
 
     public YdbDialect(DialectResolutionInfo dialectResolutionInfo) {
         super(dialectResolutionInfo);
@@ -123,16 +121,8 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
     }
 
     @Override
-    public String getQueryHintString(String query, String hints) {
-        Matcher matcher = SELECT_FROM_WHERE_QUERY_PATTERN.matcher(query);
-        if (matcher.matches() && matcher.groupCount() > 1) {
-            String startToken = matcher.group(1);
-            String endToken = matcher.group(2);
-
-            return startToken + " view " + hints + " " + endToken;
-        } else {
-            return query;
-        }
+    public String getQueryHintString(String query, List<String> hintList) {
+        return IndexQueryHintHandler.INSTANCE.addQueryHints(query, hintList);
     }
 
     @Override

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

@@ -0,0 +1,43 @@
+package tech.ydb.hibernate.dialect.hint;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * @author Kirill Kurdyukov
+ */
+public class IndexQueryHintHandler {
+    private static final Pattern SELECT_FROM_WHERE_QUERY_PATTERN = Pattern
+            .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) {
+        if (hints.isEmpty()) {
+            return query;
+        }
+
+        var useIndexes = new ArrayList<String>();
+        hints.forEach(hint -> {
+            var hintSplit = hint.split(":");
+            if (hintSplit.length == 2 && hintSplit[0].equals(HINT_USE_INDEX)) {
+                useIndexes.add(hintSplit[1]);
+            }
+        });
+
+        if (!useIndexes.isEmpty()) {
+            Matcher matcher = SELECT_FROM_WHERE_QUERY_PATTERN.matcher(query);
+            if (matcher.matches() && matcher.groupCount() > 1) {
+                String startToken = matcher.group(1);
+                String endToken = matcher.group(2);
+
+                return startToken + " view " + String.join(", ", useIndexes) + endToken;
+            }
+        }
+
+        return query;
+    }
+}

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

@@ -165,7 +165,7 @@ void groupByGroupName_ViewIndex() {
                 session -> {
                     Group group = session
                             .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
-                            .addQueryHint("group_name_index")
+                            .addQueryHint("use_index:group_name_index")
                             .getSingleResult();
 
                     assertEquals("M3439", group.getName());