✨ #4 Custom type for Class type;

Also adding CLASS_NAME() function

src/main/java/org/moditect/jfranalytics/GetClassNameFunction.java

@@ -0,0 +1,34 @@
+/*
+ *  Copyright 2021 The original authors
+ *
+ *  Licensed 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.moditect.jfranalytics;
+
+import org.apache.calcite.schema.ScalarFunction;
+import org.apache.calcite.schema.impl.ScalarFunctionImpl;
+
+import jdk.jfr.consumer.RecordedClass;
+
+public class GetClassNameFunction {
+
+    public static final ScalarFunction INSTANCE = ScalarFunctionImpl.create(GetClassNameFunction.class, "eval");
+
+    public String eval(Object recordedClass) {
+        if (!(recordedClass instanceof RecordedClass)) {
+            System.out.println(recordedClass);
+            throw new RuntimeException("BOOM");
+        }
+        return ((RecordedClass) recordedClass).getName();
+    }
+}

src/main/java/org/moditect/jfranalytics/JfrSchema.java

@@ -46,6 +46,7 @@
 import jdk.jfr.Timespan;
 import jdk.jfr.ValueDescriptor;
 import jdk.jfr.consumer.EventStream;
+import jdk.jfr.consumer.RecordedClass;
 
 public class JfrSchema implements Schema {
 
@@ -75,7 +76,12 @@ private static Map<String, JfrScannableTable> getTableTypes(Path jfrFile) {
                             continue;
                         }
 
+                        // if (type.getSqlTypeName().toString().equals("ROW")) {
+                        // builder.add(field.getName(), type).nullable(true);
+                        // }
+
                         builder.add(field.getName(), type.getSqlTypeName()).nullable(true);
+
                         converters.add(getConverter(field, type));
                     }
 
@@ -107,7 +113,7 @@ private static RelDataType getRelDataType(EventType eventType, ValueDescriptor f
                 }
                 break;
             case "java.lang.Class":
-                type = typeFactory.createJavaType(String.class);
+                type = typeFactory.createJavaType(RecordedClass.class);
                 break;
             case "java.lang.String":
                 type = typeFactory.createJavaType(String.class);
@@ -119,7 +125,7 @@ private static RelDataType getRelDataType(EventType eventType, ValueDescriptor f
                 type = typeFactory.createJavaType(String.class);
                 break;
             default:
-                LOGGER.log(Level.WARNING, "Unknown attribute type: {0}; event type {1}", field.getTypeName(), eventType.getName());
+                LOGGER.log(Level.WARNING, "Unknown type of attribute {0}::{1}: {2}", eventType.getName(), field.getName(), field.getTypeName());
                 type = null;
         }
         return type;
@@ -148,7 +154,7 @@ else if (type != null && type.getSqlTypeName() == SqlTypeName.BIGINT) {
             }
             else {
                 if (field.getTypeName().equals("java.lang.Class")) {
-                    return event -> event.getClass(field.getName()).getName();
+                    return event -> event.getClass(field.getName());
                 }
                 else {
                     return event -> event.getValue(field.getName());
@@ -179,12 +185,16 @@ public Set<String> getTypeNames() {
 
     @Override
     public Collection<Function> getFunctions(String name) {
+        if (name.equals("CLASS_NAME")) {
+            return Collections.singleton(GetClassNameFunction.INSTANCE);
+        }
+
         return Collections.emptySet();
     }
 
     @Override
     public Set<String> getFunctionNames() {
-        return Collections.emptySet();
+        return Set.of("CLASS_NAME");
     }
 
     @Override

src/test/java/org/moditect/jfranalytics/JfrSchemaFactoryTest.java

@@ -157,6 +157,62 @@ public void canRunSimpleSelectFromGarbageCollection() throws Exception {
         }
     }
 
+    @Test
+    public void canRunSimpleSelectFromClassLoad() throws Exception {
+        try (Connection connection = DriverManager.getConnection("jdbc:calcite:", getConnectionProperties("class-loading.jfr"))) {
+            PreparedStatement statement = connection.prepareStatement("""
+                    SELECT "startTime", "loadedClass"
+                    FROM "jfr"."jdk.ClassLoad"
+                    ORDER by "startTime"
+                    LIMIT 1
+                    """);
+
+            try (ResultSet rs = statement.executeQuery()) {
+                assertThat(rs.next()).isTrue();
+
+                assertThat(rs.getTimestamp(1)).isEqualTo(Timestamp.from(ZonedDateTime.parse("2021-12-26T17:32:45.428000000+01:00").toInstant()));
+                assertThat(rs.getString(2)).isEqualTo("""
+                        {
+                          classLoader = null
+                          name = "java/lang/Throwable"
+                          package = {
+                            name = "java/lang"
+                            module = {
+                              name = "java.base"
+                              version = "17"
+                              location = "jrt:/java.base"
+                              classLoader = null
+                            }
+                            exported = true
+                          }
+                          modifiers = 33
+                          hidden = false
+                        }
+                        """);
+
+                assertThat(rs.next()).isFalse();
+            }
+        }
+    }
+
+    @Test
+    public void canUseGetClassNameFunction() throws Exception {
+        try (Connection connection = DriverManager.getConnection("jdbc:calcite:", getConnectionProperties("class-loading.jfr"))) {
+            PreparedStatement statement = connection.prepareStatement("""
+                    SELECT CLASS_NAME("loadedClass") as className
+                    FROM "jfr"."jdk.ClassLoad"
+                    ORDER by "startTime"
+                    LIMIT 1
+                    """);
+
+            try (ResultSet rs = statement.executeQuery()) {
+                assertThat(rs.next()).isTrue();
+                assertThat(rs.getString(1)).isEqualTo("java.lang.Throwable");
+                assertThat(rs.next()).isFalse();
+            }
+        }
+    }
+
     @Test
     public void canRunAggregation() throws Exception {
         try (Connection connection = DriverManager.getConnection("jdbc:calcite:", getConnectionProperties("basic.jfr"))) {