/*
* 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.nifi.schema.access;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Map;
import java.util.OptionalInt;
import java.util.OptionalLong;
import java.util.Set;
import org.apache.nifi.serialization.record.RecordSchema;
import org.apache.nifi.serialization.record.SchemaIdentifier;
public class HortonworksEncodedSchemaReferenceWriter implements SchemaAccessWriter {
private static final Set<SchemaField> requiredSchemaFields = EnumSet.of(SchemaField.SCHEMA_IDENTIFIER, SchemaField.SCHEMA_VERSION);
private static final int LATEST_PROTOCOL_VERSION = 1;
@Override
public void writeHeader(final RecordSchema schema, final OutputStream out) throws IOException {
final SchemaIdentifier identifier = schema.getIdentifier();
final long id = identifier.getIdentifier().getAsLong();
final int version = identifier.getVersion().getAsInt();
// This decoding follows the pattern that is provided for serializing data by the Hortonworks Schema Registry serializer
// as it is provided at:
// https://github.com/hortonworks/registry/blob/master/schema-registry/serdes/src/main/java/com/hortonworks/registries/schemaregistry/serdes/avro/AvroSnapshotSerializer.java
final ByteBuffer bb = ByteBuffer.allocate(14);
bb.put((byte) LATEST_PROTOCOL_VERSION);
bb.putLong(id);
bb.putInt(version);
bb.put((byte) 0); // We always use generic records
out.write(bb.array());
}
@Override
public Map<String, String> getAttributes(final RecordSchema schema) {
return Collections.emptyMap();
}
@Override
public void validateSchema(RecordSchema schema) throws SchemaNotFoundException {
final SchemaIdentifier identifier = schema.getIdentifier();
final OptionalLong identifierOption = identifier.getIdentifier();
if (!identifierOption.isPresent()) {
throw new SchemaNotFoundException("Cannot write Encoded Schema Reference because the Schema Identifier is not known");
}
final OptionalInt versionOption = identifier.getVersion();
if (!versionOption.isPresent()) {
throw new SchemaNotFoundException("Cannot write Encoded Schema Reference because the Schema Version is not known");
}
}
@Override
public Set<SchemaField> getRequiredSchemaFields() {
return requiredSchemaFields;
}
}