Support external/alien MVEL UDF

feathr-impl/src/main/java/com/linkedin/feathr/common/util/MvelContextUDFs.java

@@ -37,9 +37,9 @@ public class MvelContextUDFs {
   private MvelContextUDFs() { }
 
   // register all the udfs defined in this class to the specific parser config
-  public static void registerUDFs(ParserConfiguration parserConfig) {
+  public static void registerUDFs(Class<?> clazz, ParserConfiguration parserConfig) {
     // Scans the class (MvelContextUDFs) for any methods annotated with ExportToMvel
-    for (Method method : MvelContextUDFs.class.getMethods()) {
+    for (Method method : clazz.getMethods()) {
       if (method.isAnnotationPresent(ExportToMvel.class)) {
         if (!Modifier.isStatic(method.getModifiers())) {
           throw new Error("MVEL context set up incorrectly. Imported method " + method + " must be static but is not.");
@@ -53,7 +53,7 @@ public static void registerUDFs(ParserConfiguration parserConfig) {
   // parser context. Basically this is a way of adding UDFs.
   @Retention(RetentionPolicy.RUNTIME)
   @Target(ElementType.METHOD)
-  private @interface ExportToMvel { }
+  public @interface ExportToMvel { }
 
   /**
    * Get the class type of the input object

feathr-impl/src/main/scala/com/linkedin/feathr/offline/mvel/MvelContext.java

@@ -8,6 +8,7 @@
 import org.apache.avro.generic.GenericEnumSymbol;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.util.Utf8;
+import org.apache.spark.broadcast.Broadcast;
 import org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema;
 import org.mvel2.MVEL;
 import org.mvel2.ParserConfiguration;
@@ -31,10 +32,13 @@ private MvelContext() { }
 
   private static final ParserConfiguration PARSER_CONFIG = new ParserConfiguration();
 
-
+  // External UDF register class
+  public static Optional<Broadcast<Class<?>>> mvelAlienUDFRegisterClazz = Optional.empty();
+  // Flag to avoid init external UDF everytime
+  public static Boolean alienUDFInitialized = false;
   static {
 
-    MvelContextUDFs.registerUDFs(PARSER_CONFIG);
+    MvelContextUDFs.registerUDFs(MvelContextUDFs.class, PARSER_CONFIG);
 
     loadJavaClasses();
 
@@ -98,7 +102,10 @@ private static void loadJavaClasses() {
 
   // ensure the class is loaded in memory.
   public static void ensureInitialized() {
-
+    if (!alienUDFInitialized && mvelAlienUDFRegisterClazz.isPresent()) {
+      MvelContextUDFs.registerUDFs(mvelAlienUDFRegisterClazz.get().getValue(), PARSER_CONFIG);
+      alienUDFInitialized = true;
+    }
   }
 
   /**

feathr-impl/src/main/scala/com/linkedin/feathr/offline/mvel/plugins/FeathrExpressionExecutionContext.scala

@@ -1,13 +1,15 @@
 package com.linkedin.feathr.offline.mvel.plugins
 
 import com.linkedin.feathr.common.FeatureValue
+import com.linkedin.feathr.offline.mvel.MvelContext
 import org.apache.spark.SparkContext
 import org.apache.spark.broadcast.Broadcast
 import org.mvel2.ConversionHandler
 import org.mvel2.conversion.ArrayHandler
 import org.mvel2.util.ReflectionUtil.{isAssignableFrom, toNonPrimitiveType}
 
 import java.io.Serializable
+import java.util.Optional
 import scala.collection.mutable
 
 /**
@@ -43,13 +45,21 @@ class FeathrExpressionExecutionContext extends Serializable {
    * @param typeAdaptor the type adaptor that can convert between the "other" representation and {@link FeatureValue}
    * @param <           T> type parameter for the "other" feature value class
    */
-  def setupExecutorMvelContext[T](clazz: Class[T], typeAdaptor: FeatureValueTypeAdaptor[T], sc: SparkContext): Unit = {
+  def setupExecutorMvelContext[T](clazz: Class[T],
+                                  typeAdaptor: FeatureValueTypeAdaptor[T],
+                                  sc: SparkContext,
+                                  mvelExtContext: Option[Class[Any]] = None): Unit = {
     localFeatureValueTypeAdaptors.put(clazz.getCanonicalName, typeAdaptor.asInstanceOf[FeatureValueTypeAdaptor[AnyRef]])
     featureValueTypeAdaptors = sc.broadcast(localFeatureValueTypeAdaptors)
     // Add a converter that can convert external data to feature value
     addConversionHandler(classOf[FeatureValue], new ExternalDataToFeatureValueHandler(featureValueTypeAdaptors), sc)
     // Add a converter that can convert a feature value to external data
     addConversionHandler(clazz, new FeatureValueToExternalDataHandler(typeAdaptor), sc)
+    MvelContext.mvelAlienUDFRegisterClazz = if (mvelExtContext.isDefined) {
+      Optional.of(sc.broadcast(mvelExtContext.get))
+    } else {
+      Optional.empty()
+    }
   }
 
   /**

feathr-impl/src/test/java/com/linkedin/feathr/common/AlienMvelContextUDFs.java

@@ -0,0 +1,37 @@
+package com.linkedin.feathr.common;
+
+import com.linkedin.feathr.common.util.MvelContextUDFs;
+
+/**
+ *
+ * MVEL is an open-source expression language and runtime that makes it easy to write concise statements that operate
+ * on structured data objects (such as Avro records), among other things.
+ *
+ * This class contains all the udfs used in Mvel for both online and offline
+ */
+public class AlienMvelContextUDFs {
+  // The udf naming in this class should use a_b_c form. (to be consistent with existing Spark built-in UDFs).
+  private AlienMvelContextUDFs() { }
+
+
+  /**
+   * convert input to upper case string
+   * @param input input string
+   * @return upper case input
+   */
+  @MvelContextUDFs.ExportToMvel
+  public static String toUpperCaseExt(String input) {
+    return input.toUpperCase();
+  }
+  /**
+   * convert input to upper case string
+   * @param input input string
+   * @return upper case input
+   */
+  @MvelContextUDFs.ExportToMvel
+  public static String toUpperCase(String input) {
+    return input.toUpperCase();
+  }
+
+}
+

feathr-impl/src/test/java/com/linkedin/feathr/common/util/MvelUDFExpressionTests.java

@@ -1,9 +1,10 @@
 package com.linkedin.feathr.common.util;
 
 import java.io.Serializable;
-import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.List;
+
+import com.linkedin.feathr.common.AlienMvelContextUDFs;
 import org.mvel2.MVEL;
 import org.mvel2.ParserConfiguration;
 import org.mvel2.ParserContext;
@@ -23,10 +24,18 @@ public class MvelUDFExpressionTests {
 
   @BeforeClass
   public void setup() {
-    MvelContextUDFs.registerUDFs(PARSER_CONFIG);
+    MvelContextUDFs.registerUDFs(MvelContextUDFs.class, PARSER_CONFIG);
+    MvelContextUDFs.registerUDFs(AlienMvelContextUDFs.class, PARSER_CONFIG);
     parserContext = new ParserContext(PARSER_CONFIG);
   }
 
+  @Test
+  public void testToUpperCaseExt() {
+    String getTopTerm = "toUpperCaseExt('hello')";
+    Serializable compiledExpression = MVEL.compileExpression(getTopTerm, parserContext);
+    String res = (String) (MVEL.executeExpression(compiledExpression, ""));
+    Assert.assertEquals(res, "HELLO");
+  }
 
   @Test
   public void testGetTopTerm() {

feathr-impl/src/test/scala/com/linkedin/feathr/offline/AnchoredFeaturesIntegTest.scala

@@ -294,7 +294,7 @@ class AnchoredFeaturesIntegTest extends FeathrIntegTest {
                              | anchors: {
                              |  anchor1: {
                              |    source: "anchorAndDerivations/nullValueSource.avro.json"
-                             |    key: "mId"
+                             |    key: "toUpperCaseExt(mId)"
                              |    features: {
                              |      featureWithNull: "isPresent(value) ? toNumeric(value) : 0"
                              |    }

feathr-impl/src/test/scala/com/linkedin/feathr/offline/TestFeathr.scala

@@ -1,7 +1,7 @@
 package com.linkedin.feathr.offline
 
 import com.linkedin.feathr.common
-import com.linkedin.feathr.common.JoiningFeatureParams
+import com.linkedin.feathr.common.{AlienMvelContextUDFs, JoiningFeatureParams}
 import com.linkedin.feathr.offline.client.FeathrClient
 import com.linkedin.feathr.offline.config.{FeathrConfig, FeathrConfigLoader}
 import com.linkedin.feathr.offline.mvel.plugins.FeathrExpressionExecutionContext
@@ -31,7 +31,11 @@ abstract class TestFeathr {
   @BeforeClass
   def setup(): Unit = {
     setupSpark()
-    mvelContext.setupExecutorMvelContext(classOf[AlienFeatureValue], new AlienFeatureValueTypeAdaptor(), ss.sparkContext)
+    mvelContext.setupExecutorMvelContext(classOf[AlienFeatureValue],
+      new AlienFeatureValueTypeAdaptor(),
+      ss.sparkContext,
+      Some(classOf[AlienMvelContextUDFs].asInstanceOf[Class[Any]])
+    )
   }
 
   /**

gradle.properties

@@ -1,3 +1,3 @@
-version=0.10.4-rc1
+version=0.10.4-rc2
 SONATYPE_AUTOMATIC_RELEASE=true
 POM_ARTIFACT_ID=feathr_2.12