[HUDI-3568] Introduce ChainedSchemaPostProcessor to support setting multi processors at once (#4968)

hudi-utilities/src/main/java/org/apache/hudi/utilities/UtilHelpers.java

@@ -18,7 +18,6 @@
 
 package org.apache.hudi.utilities;
 
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hudi.AvroConversionUtils;
 import org.apache.hudi.client.SparkRDDWriteClient;
 import org.apache.hudi.client.WriteStatus;
@@ -44,6 +43,8 @@ import org.apache.hudi.exception.HoodieIOException;
 import org.apache.hudi.index.HoodieIndex;
 import org.apache.hudi.utilities.checkpointing.InitialCheckPointProvider;
 import org.apache.hudi.utilities.deltastreamer.HoodieDeltaStreamerMetrics;
+import org.apache.hudi.utilities.exception.HoodieSchemaPostProcessException;
+import org.apache.hudi.utilities.schema.ChainedSchemaPostProcessor;
 import org.apache.hudi.utilities.schema.DelegatingSchemaProvider;
 import org.apache.hudi.utilities.schema.RowBasedSchemaProvider;
 import org.apache.hudi.utilities.schema.SchemaPostProcessor;
@@ -57,6 +58,7 @@ import org.apache.hudi.utilities.transform.ChainedTransformer;
 import org.apache.hudi.utilities.transform.Transformer;
 
 import org.apache.avro.Schema;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -143,10 +145,22 @@ public class UtilHelpers {
   }
 
   public static SchemaPostProcessor createSchemaPostProcessor(
-      String schemaPostProcessorClass, TypedProperties cfg, JavaSparkContext jssc) {
+      String schemaPostProcessorClassNames, TypedProperties cfg, JavaSparkContext jssc) {
-    return schemaPostProcessorClass == null
+
-        ? null
+    if (StringUtils.isNullOrEmpty(schemaPostProcessorClassNames)) {
-        : (SchemaPostProcessor) ReflectionUtils.loadClass(schemaPostProcessorClass, cfg, jssc);
+      return null;
+    }
+
+    try {
+      List<SchemaPostProcessor> processors = new ArrayList<>();
+      for (String className : (schemaPostProcessorClassNames.split(","))) {
+        processors.add((SchemaPostProcessor) ReflectionUtils.loadClass(className, cfg, jssc));
+      }
+      return new ChainedSchemaPostProcessor(cfg, jssc, processors);
+    } catch (Throwable e) {
+      throw new HoodieSchemaPostProcessException("Could not load schemaPostProcessorClassNames class(es) " + schemaPostProcessorClassNames, e);
+    }
+
   }
 
   public static Option<Transformer> createTransformer(List<String> classNames) throws IOException {
@@ -164,7 +178,7 @@ public class UtilHelpers {
   public static InitialCheckPointProvider createInitialCheckpointProvider(
       String className, TypedProperties props) throws IOException {
     try {
-      return (InitialCheckPointProvider) ReflectionUtils.loadClass(className, new Class<?>[] {TypedProperties.class}, props);
+      return (InitialCheckPointProvider) ReflectionUtils.loadClass(className, new Class<?>[]{TypedProperties.class}, props);
     } catch (Throwable e) {
       throw new IOException("Could not load initial checkpoint provider class " + className, e);
     }
@@ -428,7 +442,7 @@ public class UtilHelpers {
     }
 
     if (provider instanceof SchemaProviderWithPostProcessor) {
-      return (SchemaProviderWithPostProcessor)provider;
+      return (SchemaProviderWithPostProcessor) provider;
     }
 
     String schemaPostProcessorClass = cfg.getString(Config.SCHEMA_POST_PROCESSOR_PROP, null);

hudi-utilities/src/main/java/org/apache/hudi/utilities/exception/HoodieSchemaPostProcessException.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.hudi.utilities.exception;
+
+import org.apache.hudi.exception.HoodieException;
+
+/**
+ * Exception throws during schema post process.
+ */
+public class HoodieSchemaPostProcessException  extends HoodieException {
+  public HoodieSchemaPostProcessException(String msg) {
+    super(msg);
+  }
+
+  public HoodieSchemaPostProcessException(String message, Throwable t) {
+    super(message, t);
+  }
+}

hudi-utilities/src/main/java/org/apache/hudi/utilities/schema/ChainedSchemaPostProcessor.java

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.hudi.utilities.schema;
+
+import org.apache.hudi.common.config.TypedProperties;
+
+import org.apache.avro.Schema;
+import org.apache.spark.api.java.JavaSparkContext;
+
+import java.util.List;
+
+/**
+ * A {@link SchemaPostProcessor} to chain other {@link SchemaPostProcessor}s and process sequentially.
+ */
+public class ChainedSchemaPostProcessor extends SchemaPostProcessor {
+
+  private List<SchemaPostProcessor> processors;
+
+  protected ChainedSchemaPostProcessor(TypedProperties props, JavaSparkContext jssc) {
+    super(props, jssc);
+  }
+
+  public ChainedSchemaPostProcessor(TypedProperties props, JavaSparkContext jssc, List<SchemaPostProcessor> processors) {
+    super(props, jssc);
+    this.processors = processors;
+  }
+
+  @Override
+  public Schema processSchema(Schema schema) {
+    Schema targetSchema = schema;
+    for (SchemaPostProcessor processor : processors) {
+      targetSchema = processor.processSchema(targetSchema);
+    }
+    return targetSchema;
+  }
+}

hudi-utilities/src/test/java/org/apache/hudi/utilities/DummySchemaPostProcessor.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.hudi.utilities;
+
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.utilities.schema.SchemaPostProcessor;
+
+import org.apache.avro.Schema;
+import org.apache.avro.SchemaBuilder;
+import org.apache.spark.api.java.JavaSparkContext;
+
+public class DummySchemaPostProcessor  extends SchemaPostProcessor {
+
+  public DummySchemaPostProcessor(TypedProperties props, JavaSparkContext jssc) {
+    super(props, jssc);
+  }
+
+  @Override
+  public Schema processSchema(Schema schema) {
+    return SchemaBuilder.record("test").fields().optionalString("testString").endRecord();
+  }
+
+}

hudi-utilities/src/test/java/org/apache/hudi/utilities/TestSchemaPostProcessor.java

@@ -29,8 +29,6 @@ import org.apache.hudi.utilities.transform.FlatteningTransformer;
 
 import org.apache.avro.Schema;
 import org.apache.avro.Schema.Type;
-import org.apache.avro.SchemaBuilder;
-import org.apache.spark.api.java.JavaSparkContext;
 import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
@@ -39,6 +37,7 @@ import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 public class TestSchemaPostProcessor extends UtilitiesTestBase {
 
@@ -90,22 +89,37 @@ public class TestSchemaPostProcessor extends UtilitiesTestBase {
     assertNotNull(targetSchema.getField("_hoodie_is_deleted"));
   }
 
+  @Test
+  public void testChainedSchemaPostProcessor() {
+    // DeleteSupportSchemaPostProcessor first, DummySchemaPostProcessor second
+    properties.put(Config.SCHEMA_POST_PROCESSOR_PROP,
+        "org.apache.hudi.utilities.schema.DeleteSupportSchemaPostProcessor,org.apache.hudi.utilities.DummySchemaPostProcessor");
+
+    SchemaPostProcessor processor = UtilHelpers.createSchemaPostProcessor(properties.getString(Config.SCHEMA_POST_PROCESSOR_PROP), properties, jsc);
+    Schema schema = new Schema.Parser().parse(ORIGINAL_SCHEMA);
+    Schema targetSchema = processor.processSchema(schema);
+
+    assertNull(targetSchema.getField("ums_id_"));
+    assertNull(targetSchema.getField("_hoodie_is_deleted"));
+    assertNotNull(targetSchema.getField("testString"));
+
+    // DummySchemaPostProcessor first, DeleteSupportSchemaPostProcessor second
+    properties.put(Config.SCHEMA_POST_PROCESSOR_PROP,
+        "org.apache.hudi.utilities.DummySchemaPostProcessor,org.apache.hudi.utilities.schema.DeleteSupportSchemaPostProcessor");
+
+    processor = UtilHelpers.createSchemaPostProcessor(properties.getString(Config.SCHEMA_POST_PROCESSOR_PROP), properties, jsc);
+    schema = new Schema.Parser().parse(ORIGINAL_SCHEMA);
+    targetSchema = processor.processSchema(schema);
+
+    assertNull(targetSchema.getField("ums_id_"));
+    assertNotNull(targetSchema.getField("_hoodie_is_deleted"));
+    assertNotNull(targetSchema.getField("testString"));
+  }
+
   @Test
   public void testSparkAvroSchema() throws IOException {
     SparkAvroPostProcessor processor = new SparkAvroPostProcessor(properties, null);
     Schema schema = new Schema.Parser().parse(ORIGINAL_SCHEMA);
     assertEquals(processor.processSchema(schema).toString(), RESULT_SCHEMA);
   }
-
-  public static class DummySchemaPostProcessor extends SchemaPostProcessor {
-
-    public DummySchemaPostProcessor(TypedProperties props, JavaSparkContext jssc) {
-      super(props, jssc);
-    }
-
-    @Override
-    public Schema processSchema(Schema schema) {
-      return SchemaBuilder.record("test").fields().optionalString("testString").endRecord();
-    }
-  }
 }