Merge pull request #27991: Refactor ConvertHelpers in "core" to not d…

…epend on Avro

sdks/java/core/src/main/java/org/apache/beam/sdk/schemas/utils/ConvertHelpers.java

@@ -22,6 +22,7 @@
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Type;
+import java.util.ServiceLoader;
 import net.bytebuddy.ByteBuddy;
 import net.bytebuddy.asm.AsmVisitorWrapper;
 import net.bytebuddy.description.type.TypeDescription;
@@ -35,7 +36,6 @@
 import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
 import net.bytebuddy.jar.asm.ClassWriter;
 import net.bytebuddy.matcher.ElementMatchers;
-import org.apache.avro.generic.GenericRecord;
 import org.apache.beam.sdk.schemas.JavaFieldSchema.JavaFieldTypeSupplier;
 import org.apache.beam.sdk.schemas.NoSuchSchemaException;
 import org.apache.beam.sdk.schemas.Schema;
@@ -45,7 +45,6 @@
 import org.apache.beam.sdk.schemas.utils.ByteBuddyUtils.TypeConversionsFactory;
 import org.apache.beam.sdk.transforms.SerializableFunction;
 import org.apache.beam.sdk.util.common.ReflectHelpers;
-import org.apache.beam.sdk.values.Row;
 import org.apache.beam.sdk.values.TypeDescriptor;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.primitives.Primitives;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -58,6 +57,11 @@
   "rawtypes"
 })
 public class ConvertHelpers {
+  private static class SchemaInformationProviders {
+    private static final ServiceLoader<SchemaInformationProvider> INSTANCE =
+        ServiceLoader.load(SchemaInformationProvider.class);
+  }
+
   private static final Logger LOG = LoggerFactory.getLogger(ConvertHelpers.class);
 
   /** Return value after converting a schema. */
@@ -80,17 +84,17 @@ public ConvertedSchemaInformation(
   /** Get the coder used for converting from an inputSchema to a given type. */
   public static <T> ConvertedSchemaInformation<T> getConvertedSchemaInformation(
       Schema inputSchema, TypeDescriptor<T> outputType, SchemaRegistry schemaRegistry) {
-    ConvertedSchemaInformation<T> convertedSchema = null;
-    if (outputType.equals(TypeDescriptor.of(Row.class))) {
-      // If the output is of type Row, then just forward the schema of the input type to the
-      // output.
-      convertedSchema =
-          new ConvertedSchemaInformation<>((SchemaCoder<T>) SchemaCoder.of(inputSchema), null);
-    } else if (outputType.equals(TypeDescriptor.of(GenericRecord.class))) {
-      convertedSchema =
-          new ConvertedSchemaInformation<T>(
-              (SchemaCoder<T>) AvroUtils.schemaCoder(AvroUtils.toAvroSchema(inputSchema)), null);
-    } else {
+
+    ConvertedSchemaInformation<T> schemaInformation = null;
+    // Try to load schema information from loaded providers
+    for (SchemaInformationProvider provider : SchemaInformationProviders.INSTANCE) {
+      schemaInformation = provider.getConvertedSchemaInformation(inputSchema, outputType);
+      if (schemaInformation != null) {
+        return schemaInformation;
+      }
+    }
+
+    if (schemaInformation == null) {
       // Otherwise, try to find a schema for the output type in the schema registry.
       Schema outputSchema = null;
       SchemaCoder<T> outputSchemaCoder = null;
@@ -129,9 +133,9 @@ public static <T> ConvertedSchemaInformation<T> getConvertedSchemaInformation(
                   + outputSchema);
         }
       }
-      convertedSchema = new ConvertedSchemaInformation<T>(outputSchemaCoder, unboxedType);
+      schemaInformation = new ConvertedSchemaInformation<T>(outputSchemaCoder, unboxedType);
     }
-    return convertedSchema;
+    return schemaInformation;
   }
 
   /**

sdks/java/core/src/main/java/org/apache/beam/sdk/schemas/utils/RowSchemaInformationProvider.java

@@ -0,0 +1,41 @@
+/*
+ * 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.beam.sdk.schemas.utils;
+
+import com.google.auto.service.AutoService;
+import javax.annotation.Nullable;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.SchemaCoder;
+import org.apache.beam.sdk.values.Row;
+import org.apache.beam.sdk.values.TypeDescriptor;
+
+@AutoService(SchemaInformationProvider.class)
+public class RowSchemaInformationProvider implements SchemaInformationProvider {
+  @Override
+  @Nullable
+  public <T> ConvertHelpers.ConvertedSchemaInformation<T> getConvertedSchemaInformation(
+      Schema inputSchema, TypeDescriptor<T> outputType) {
+    if (outputType.equals(TypeDescriptor.of(Row.class))) {
+      // If the output is of type Row, then just forward the schema of the input type to the
+      // output.
+      return new ConvertHelpers.ConvertedSchemaInformation<>(
+          (SchemaCoder<T>) SchemaCoder.of(inputSchema), null);
+    }
+    return null;
+  }
+}

sdks/java/core/src/main/java/org/apache/beam/sdk/schemas/utils/SchemaInformationProvider.java

@@ -0,0 +1,32 @@
+/*
+ * 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.beam.sdk.schemas.utils;
+
+import javax.annotation.Nullable;
+import org.apache.beam.sdk.annotations.Internal;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.utils.ConvertHelpers.ConvertedSchemaInformation;
+import org.apache.beam.sdk.values.TypeDescriptor;
+
+/** Provides an instance of {@link ConvertedSchemaInformation}. Use for internal purposes. */
+@Internal
+public interface SchemaInformationProvider {
+  @Nullable
+  <T> ConvertedSchemaInformation<T> getConvertedSchemaInformation(
+      Schema inputSchema, TypeDescriptor<T> outputType);
+}

sdks/java/extensions/avro/src/main/java/org/apache/beam/sdk/extensions/avro/schemas/utils/AvroSchemaInformationProvider.java

@@ -0,0 +1,42 @@
+/*
+ * 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.beam.sdk.extensions.avro.schemas.utils;
+
+import com.google.auto.service.AutoService;
+import javax.annotation.Nullable;
+import org.apache.avro.generic.GenericRecord;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.SchemaCoder;
+import org.apache.beam.sdk.schemas.utils.ConvertHelpers;
+import org.apache.beam.sdk.schemas.utils.SchemaInformationProvider;
+import org.apache.beam.sdk.values.TypeDescriptor;
+
+@AutoService(SchemaInformationProvider.class)
+public class AvroSchemaInformationProvider implements SchemaInformationProvider {
+
+  @Override
+  @Nullable
+  public <T> ConvertHelpers.ConvertedSchemaInformation<T> getConvertedSchemaInformation(
+      Schema inputSchema, TypeDescriptor<T> outputType) {
+    if (outputType.equals(TypeDescriptor.of(GenericRecord.class))) {
+      return new ConvertHelpers.ConvertedSchemaInformation<T>(
+          (SchemaCoder<T>) AvroUtils.schemaCoder(AvroUtils.toAvroSchema(inputSchema)), null);
+    }
+    return null;
+  }
+}