org.apache.kafka.common.requests.MetadataRequest Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.kafka.common.requests;
import org.apache.kafka.common.errors.UnsupportedVersionException;
import org.apache.kafka.common.protocol.ApiKeys;
import org.apache.kafka.common.protocol.Errors;
import org.apache.kafka.common.protocol.types.ArrayOf;
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.utils.Utils;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import static org.apache.kafka.common.protocol.types.Type.STRING;
public class MetadataRequest extends AbstractRequest {
private static final String TOPICS_KEY_NAME = "topics";
private static final Schema METADATA_REQUEST_V0 = new Schema(
new Field(TOPICS_KEY_NAME, new ArrayOf(STRING), "An array of topics to fetch metadata for. If no topics are specified fetch metadata for all topics."));
private static final Schema METADATA_REQUEST_V1 = new Schema(
new Field(TOPICS_KEY_NAME, ArrayOf.nullable(STRING), "An array of topics to fetch metadata for. If the topics array is null fetch metadata for all topics."));
/* The v2 metadata request is the same as v1. An additional field for cluster id has been added to the v2 metadata response */
private static final Schema METADATA_REQUEST_V2 = METADATA_REQUEST_V1;
/* The v3 metadata request is the same as v1 and v2. An additional field for throttle time has been added to the v3 metadata response */
private static final Schema METADATA_REQUEST_V3 = METADATA_REQUEST_V2;
/* The v4 metadata request has an additional field for allowing auto topic creation. The response is the same as v3. */
private static final Field.Bool ALLOW_AUTO_TOPIC_CREATION = new Field.Bool("allow_auto_topic_creation",
"If this and the broker config auto.create.topics.enable are true, topics that " +
"don't exist will be created by the broker. Otherwise, no topics will be created by the broker.");
private static final Schema METADATA_REQUEST_V4 = new Schema(
new Field(TOPICS_KEY_NAME, ArrayOf.nullable(STRING), "An array of topics to fetch metadata for. " +
"If the topics array is null fetch metadata for all topics."),
ALLOW_AUTO_TOPIC_CREATION);
/* The v5 metadata request is the same as v4. An additional field for offline_replicas has been added to the v5 metadata response */
private static final Schema METADATA_REQUEST_V5 = METADATA_REQUEST_V4;
/**
* The version number is bumped to indicate that on quota violation brokers send out responses before throttling.
*/
private static final Schema METADATA_REQUEST_V6 = METADATA_REQUEST_V5;
/**
* Bumped for the addition of the current leader epoch in the metadata response.
*/
private static final Schema METADATA_REQUEST_V7 = METADATA_REQUEST_V6;
public static Schema[] schemaVersions() {
return new Schema[] {METADATA_REQUEST_V0, METADATA_REQUEST_V1, METADATA_REQUEST_V2, METADATA_REQUEST_V3,
METADATA_REQUEST_V4, METADATA_REQUEST_V5, METADATA_REQUEST_V6, METADATA_REQUEST_V7};
}
public static class Builder extends AbstractRequest.Builder {
private static final List ALL_TOPICS = null;
// The list of topics, or null if we want to request metadata about all topics.
private final List topics;
private final boolean allowAutoTopicCreation;
public static Builder allTopics() {
// This never causes auto-creation, but we set the boolean to true because that is the default value when
// deserializing V2 and older. This way, the value is consistent after serialization and deserialization.
return new Builder(ALL_TOPICS, true);
}
public Builder(List topics, boolean allowAutoTopicCreation) {
super(ApiKeys.METADATA);
this.topics = topics;
this.allowAutoTopicCreation = allowAutoTopicCreation;
}
public List topics() {
return this.topics;
}
public boolean isAllTopics() {
return this.topics == ALL_TOPICS;
}
@Override
public MetadataRequest build(short version) {
if (version < 1)
throw new UnsupportedVersionException("MetadataRequest versions older than 1 are not supported.");
if (!allowAutoTopicCreation && version < 4)
throw new UnsupportedVersionException("MetadataRequest versions older than 4 don't support the " +
"allowAutoTopicCreation field");
return new MetadataRequest(this.topics, allowAutoTopicCreation, version);
}
@Override
public String toString() {
StringBuilder bld = new StringBuilder();
bld.append("(type=MetadataRequest").
append(", topics=");
if (topics == null) {
bld.append("");
} else {
bld.append(Utils.join(topics, ","));
}
bld.append(")");
return bld.toString();
}
}
private final List topics;
private final boolean allowAutoTopicCreation;
/**
* In v0 null is not allowed and an empty list indicates requesting all topics.
* Note: modern clients do not support sending v0 requests.
* In v1 null indicates requesting all topics, and an empty list indicates requesting no topics.
*/
public MetadataRequest(List topics, boolean allowAutoTopicCreation, short version) {
super(ApiKeys.METADATA, version);
this.topics = topics;
this.allowAutoTopicCreation = allowAutoTopicCreation;
}
public MetadataRequest(Struct struct, short version) {
super(ApiKeys.METADATA, version);
Object[] topicArray = struct.getArray(TOPICS_KEY_NAME);
if (topicArray != null) {
topics = new ArrayList<>();
for (Object topicObj: topicArray) {
topics.add((String) topicObj);
}
} else {
topics = null;
}
allowAutoTopicCreation = struct.getOrElse(ALLOW_AUTO_TOPIC_CREATION, true);
}
@Override
public AbstractResponse getErrorResponse(int throttleTimeMs, Throwable e) {
List topicMetadatas = new ArrayList<>();
Errors error = Errors.forException(e);
List partitions = Collections.emptyList();
if (topics != null) {
for (String topic : topics)
topicMetadatas.add(new MetadataResponse.TopicMetadata(error, topic, false, partitions));
}
short versionId = version();
switch (versionId) {
case 0:
case 1:
case 2:
return new MetadataResponse(Collections.emptyList(), null, MetadataResponse.NO_CONTROLLER_ID, topicMetadatas);
case 3:
case 4:
case 5:
case 6:
case 7:
return new MetadataResponse(throttleTimeMs, Collections.emptyList(), null, MetadataResponse.NO_CONTROLLER_ID, topicMetadatas);
default:
throw new IllegalArgumentException(String.format("Version %d is not valid. Valid versions for %s are 0 to %d",
versionId, this.getClass().getSimpleName(), ApiKeys.METADATA.latestVersion()));
}
}
public boolean isAllTopics() {
return topics == null;
}
public List topics() {
return topics;
}
public boolean allowAutoTopicCreation() {
return allowAutoTopicCreation;
}
public static MetadataRequest parse(ByteBuffer buffer, short version) {
return new MetadataRequest(ApiKeys.METADATA.parseRequest(version, buffer), version);
}
@Override
protected Struct toStruct() {
Struct struct = new Struct(ApiKeys.METADATA.requestSchema(version()));
if (topics == null)
struct.set(TOPICS_KEY_NAME, null);
else
struct.set(TOPICS_KEY_NAME, topics.toArray());
struct.setIfExists(ALLOW_AUTO_TOPIC_CREATION, allowAutoTopicCreation);
return struct;
}
}
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