feat: Implement incremental update protocol with multi-version compatibility (#1611)

* Add incremental protocol comparison tool

* Add protocol version on the server

* Add protocol version on the client

* Add protocol upgrade test code

* Remove the commented test method

* Centralize protocol version constant

* Extract helper methods for coreSize and maxSize

* Add cross-version compatibility tests for incremental protocol

* Fix extended parameter loss in config refresh due to protocol version misuse

* Eliminate hardcoded protocol version and implement field-level version control

* Support semantic version-aware incremental md5 comparison

* Remove protocol version mechanism

Author: mingri31164

infra/common/src/main/java/cn/hippo4j/common/model/IncrementalFieldMetadataProvider.java

@@ -0,0 +1,50 @@
+/*
+ * 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 cn.hippo4j.common.model;
+
+import java.util.Collections;
+import java.util.Map;
+
+/**
+ * Optional provider for field-version metadata.
+ * <p>
+ * Thread pool parameter models implementing this interface can explicitly declare the
+ * relationship between fields and the protocol versions that understand them. This allows
+ * the incremental content builder to omit unsupported fields for legacy clients and avoid
+ * unnecessary refresh loops triggered by unknown data.
+ */
+public interface IncrementalFieldMetadataProvider {
+
+    /**
+     * Return a mapping of field name to the minimum protocol version that can observe it.
+     *
+     * @return field -> minimum semantic version; fields not present fall back to defaults
+     */
+    default Map<String, String> getFieldVersionMetadata() {
+        return Collections.emptyMap();
+    }
+
+    /**
+     * Optional version string of the metadata definition, useful for caching or diagnostics.
+     *
+     * @return metadata version identifier, or {@code null} if not set
+     */
+    default String getFieldMetadataVersion() {
+        return null;
+    }
+}

infra/common/src/main/java/cn/hippo4j/common/model/ThreadPoolParameterInfo.java

@@ -25,6 +25,7 @@
 import lombok.experimental.Accessors;
 
 import java.io.Serializable;
+import java.util.Map;
 
 /**
  * Thread pool parameter info.
@@ -34,7 +35,7 @@
 @NoArgsConstructor
 @AllArgsConstructor
 @Accessors(chain = true)
-public class ThreadPoolParameterInfo implements ThreadPoolParameter, Serializable {
+public class ThreadPoolParameterInfo implements ThreadPoolParameter, Serializable, IncrementalFieldMetadataProvider {
 
     private static final long serialVersionUID = -7123935122108553864L;
 
@@ -127,6 +128,16 @@ public class ThreadPoolParameterInfo implements ThreadPoolParameter, Serializabl
      */
     private Integer allowCoreThreadTimeOut;
 
+    /**
+     * Field-to-minimum-version mapping used by clients to filter unsupported fields.
+     */
+    private Map<String, String> fieldVersionMetadata;
+
+    /**
+     * Optional metadata version identifier for diagnostics or caching.
+     */
+    private String fieldMetadataVersion;
+
     public Integer corePoolSizeAdapt() {
         return this.corePoolSize == null ? this.coreSize : this.corePoolSize;
     }

infra/common/src/main/java/cn/hippo4j/common/toolkit/ContentUtil.java

@@ -18,9 +18,13 @@
 package cn.hippo4j.common.toolkit;
 
 import cn.hippo4j.common.constant.Constants;
+import cn.hippo4j.common.model.IncrementalFieldMetadataProvider;
 import cn.hippo4j.common.model.ThreadPoolParameter;
 import cn.hippo4j.common.model.ThreadPoolParameterInfo;
 
+import java.util.LinkedHashMap;
+import java.util.Map;
+
 /**
  * Content util.
  */
@@ -37,8 +41,12 @@ public static String getPoolContent(ThreadPoolParameter parameter) {
         threadPoolParameterInfo.setTenantId(parameter.getTenantId())
                 .setItemId(parameter.getItemId())
                 .setTpId(parameter.getTpId())
-                .setCoreSize(parameter.getCoreSize())
-                .setMaxSize(parameter.getMaxSize())
+                .setCoreSize((parameter instanceof ThreadPoolParameterInfo)
+                        ? ((ThreadPoolParameterInfo) parameter).corePoolSizeAdapt()
+                        : parameter.getCoreSize())
+                .setMaxSize((parameter instanceof ThreadPoolParameterInfo)
+                        ? ((ThreadPoolParameterInfo) parameter).maximumPoolSizeAdapt()
+                        : parameter.getMaxSize())
                 .setQueueType(parameter.getQueueType())
                 .setCapacity(parameter.getCapacity())
                 .setKeepAliveTime(parameter.getKeepAliveTime())
@@ -48,6 +56,14 @@ public static String getPoolContent(ThreadPoolParameter parameter) {
                 .setLivenessAlarm(parameter.getLivenessAlarm())
                 .setAllowCoreThreadTimeOut(parameter.getAllowCoreThreadTimeOut())
                 .setRejectedType(parameter.getRejectedType());
+        if (parameter instanceof IncrementalFieldMetadataProvider) {
+            IncrementalFieldMetadataProvider provider = (IncrementalFieldMetadataProvider) parameter;
+            Map<String, String> metadata = provider.getFieldVersionMetadata();
+            if (metadata != null && !metadata.isEmpty()) {
+                threadPoolParameterInfo.setFieldVersionMetadata(new LinkedHashMap<>(metadata));
+            }
+            threadPoolParameterInfo.setFieldMetadataVersion(provider.getFieldMetadataVersion());
+        }
         return JSONUtil.toJSONString(threadPoolParameterInfo);
     }