/* * 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.kafka.common.record; import org.apache.kafka.common.protocol.types.Field; import org.apache.kafka.common.protocol.types.Schema; import org.apache.kafka.common.protocol.types.Struct; import org.apache.kafka.common.protocol.types.Type; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.nio.ByteBuffer; /** * Control records specify a schema for the record key which includes a version and type: * * Key => Version Type * Version => Int16 * Type => Int16 * * In the future, the version can be bumped to indicate a new schema, but it must be backwards compatible * with the current schema. In general, this means we can add new fields, but we cannot remove old ones. * * Note that control records are not considered for compaction by the log cleaner. * * The schema for the value field is left to the control record type to specify. */ public enum ControlRecordType { ABORT((short) 0), COMMIT((short) 1), // UNKNOWN is used to indicate a control type which the client is not aware of and should be ignored UNKNOWN((short) -1); private static final Logger log = LoggerFactory.getLogger(ControlRecordType.class); static final short CURRENT_CONTROL_RECORD_KEY_VERSION = 0; static final int CURRENT_CONTROL_RECORD_KEY_SIZE = 4; private static final Schema CONTROL_RECORD_KEY_SCHEMA_VERSION_V0 = new Schema( new Field("version", Type.INT16), new Field("type", Type.INT16)); final short type; ControlRecordType(short type) { this.type = type; } public Struct recordKey() { if (this == UNKNOWN) throw new IllegalArgumentException("Cannot serialize UNKNOWN control record type"); Struct struct = new Struct(CONTROL_RECORD_KEY_SCHEMA_VERSION_V0); struct.set("version", CURRENT_CONTROL_RECORD_KEY_VERSION); struct.set("type", type); return struct; } public static short parseTypeId(ByteBuffer key) { if (key.remaining() < CURRENT_CONTROL_RECORD_KEY_SIZE) throw new InvalidRecordException("Invalid value size found for end control record key. Must have " + "at least " + CURRENT_CONTROL_RECORD_KEY_SIZE + " bytes, but found only " + key.remaining()); short version = key.getShort(0); if (version < 0) throw new InvalidRecordException("Invalid version found for control record: " + version + ". May indicate data corruption"); if (version != CURRENT_CONTROL_RECORD_KEY_VERSION) log.debug("Received unknown control record key version {}. Parsing as version {}", version, CURRENT_CONTROL_RECORD_KEY_VERSION); return key.getShort(2); } public static ControlRecordType fromTypeId(short typeId) { switch (typeId) { case 0: return ABORT; case 1: return COMMIT; default: return UNKNOWN; } } public static ControlRecordType parse(ByteBuffer key) { return fromTypeId(parseTypeId(key)); } }