kafka Features 源码
kafka Features 代码
文件路径:/clients/src/main/java/org/apache/kafka/common/feature/Features.java
/*
* 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.feature;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.Objects;
import static java.util.stream.Collectors.joining;
/**
* Represents an immutable dictionary with key being feature name, and value being <VersionRangeType>.
* Also provides API to convert the features and their version ranges to/from a map.
*
* This class can be instantiated only using its factory functions, with the important ones being:
* Features.supportedFeatures(...) and Features.finalizedFeatures(...).
*
* @param <VersionRangeType> is the type of version range.
* @see SupportedVersionRange
*/
public class Features<VersionRangeType extends BaseVersionRange> {
private final Map<String, VersionRangeType> features;
/**
* Constructor is made private, as for readability it is preferred the caller uses one of the
* static factory functions for instantiation (see below).
*
* @param features Map of feature name to a type of VersionRange.
*/
private Features(Map<String, VersionRangeType> features) {
Objects.requireNonNull(features, "Provided features can not be null.");
this.features = features;
}
/**
* @param features Map of feature name to SupportedVersionRange.
*
* @return Returns a new Features object representing supported features.
*/
public static Features<SupportedVersionRange> supportedFeatures(Map<String, SupportedVersionRange> features) {
return new Features<>(features);
}
public static Features<SupportedVersionRange> emptySupportedFeatures() {
return new Features<>(new HashMap<>());
}
public Map<String, VersionRangeType> features() {
return features;
}
public boolean empty() {
return features.isEmpty();
}
/**
* @param feature name of the feature
*
* @return the VersionRangeType corresponding to the feature name, or null if the
* feature is absent
*/
public VersionRangeType get(String feature) {
return features.get(feature);
}
public String toString() {
return String.format(
"Features{%s}",
features
.entrySet()
.stream()
.map(entry -> String.format("(%s -> %s)", entry.getKey(), entry.getValue()))
.collect(joining(", "))
);
}
/**
* @return A map representation of the underlying features. The returned value can be converted
* back to Features using one of the from*FeaturesMap() APIs of this class.
*/
public Map<String, Map<String, Short>> toMap() {
return features.entrySet().stream().collect(
Collectors.toMap(
Map.Entry::getKey,
entry -> entry.getValue().toMap()));
}
/**
* An interface that defines behavior to convert from a Map to an object of type BaseVersionRange.
*/
private interface MapToBaseVersionRangeConverter<V extends BaseVersionRange> {
/**
* Convert the map representation of an object of type <V>, to an object of type <V>.
*
* @param baseVersionRangeMap the map representation of a BaseVersionRange object.
*
* @return the object of type <V>
*/
V fromMap(Map<String, Short> baseVersionRangeMap);
}
private static <V extends BaseVersionRange> Features<V> fromFeaturesMap(
Map<String, Map<String, Short>> featuresMap, MapToBaseVersionRangeConverter<V> converter) {
return new Features<>(featuresMap.entrySet().stream().collect(
Collectors.toMap(
Map.Entry::getKey,
entry -> converter.fromMap(entry.getValue()))));
}
/**
* Converts from a map to Features<SupportedVersionRange>.
*
* @param featuresMap the map representation of a Features<SupportedVersionRange> object,
* generated using the toMap() API.
*
* @return the Features<SupportedVersionRange> object
*/
public static Features<SupportedVersionRange> fromSupportedFeaturesMap(
Map<String, Map<String, Short>> featuresMap) {
return fromFeaturesMap(featuresMap, SupportedVersionRange::fromMap);
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof Features)) {
return false;
}
final Features that = (Features) other;
return Objects.equals(this.features, that.features);
}
@Override
public int hashCode() {
return Objects.hash(features);
}
}
相关信息
相关文章
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦