refactor(proto): remove unused proto discover definition

protocol/src/main/protos/Chinese version of TRON Protocol document.md

@@ -631,23 +631,27 @@
 
 +  网络UDP消息结构。
 
+  以下 UDP 节点发现消息定义位于 java-tron 仓库的 `p2p/src/main/proto/Discover.proto`。
+
   `Endpoint`：网络中节点信息存储结构.  
-  消息体`Endpoint` 包含3个参数：  
-   `address`：节点地址。  
+  消息体`Endpoint` 包含4个参数：  
+   `address`：节点的 IPv4 地址。  
    `port`：端口号。  
-   `nodeId`： 节点ID信息。
+   `nodeId`： 节点ID信息。  
+   `addressIpv6`：节点的 IPv6 地址。
 
     message Endpoint {
       bytes address = 1;
       int32 port = 2;
       bytes nodeId = 3;
+      bytes addressIpv6 = 4;
      }
 
-   `PingMessage`：节点建立连接时所发送的消息。  
+   `PingMessage`：用于 UDP 节点发现与存活探测的请求消息。  
    消息体`PingMessage` 包含4个参数：  
    `from`：消息来自的节点。  
    `to`： 消息发送的节点。  
-   `version`： 网络版本。  
+   `version`：发送节点的网络标识（`networkId`）。  
    `timestamp`：消息创建时的时间戳。
 
     message PingMessage {
@@ -657,10 +661,10 @@
        int64 timestamp = 4;
      }
 
-   `PongMessage`：连接建立成功时的回复消息。  
+   `PongMessage`：对 UDP 节点发现与存活探测请求的响应消息。  
    消息体`PongMessage` 包含3个参数：  
    `from`：消息来自的节点。  
-   `echo`：  
+   `echo`：响应节点的网络标识（`networkId`）。  
    `timestamp`：消息创建时的时间戳。
 
     message PongMessage {
@@ -669,10 +673,10 @@
       int64 timestamp = 3;
      }
 
-   `FindNeighbours`：节点查询相邻节点时所发送的消息。  
+   `FindNeighbours`：查询接近 `targetId` 的节点列表的请求消息。  
    消息体`FindNeighbours` 包含3个参数：  
    `from`: 消息来自的节点。  
-   `targetId`: 目标节点的信息。  
+   `targetId`: 用于查找邻近节点的目标节点 ID。  
    `timestamp`: 消息创建时的时间戳。
 
     message FindNeighbours {
@@ -681,11 +685,11 @@
       int64 timestamp = 3;
      }
 
-   `Neighbour`：相邻接点回复消息。  
+   `Neighbours`：对 `FindNeighbours` 请求的响应消息，返回接近 `targetId` 的节点列表。  
    消息体`Neighbours` 包含3个参数：  
    `from`: 消息来自的节点。  
-   `neighbours`: 相邻节点。  
-   `timestamp`: 消息创建时的时间戳。
+   `neighbours`: 返回的节点列表。  
+   `timestamp`: 对应 `FindNeighbours` 请求的时间戳。
 
     message Neighbours {
       Endpoint from = 1;

protocol/src/main/protos/English version of TRON Protocol document.md

@@ -666,24 +666,28 @@ Input, transaction and head block all require signature.
 
 + The message structure of UDP.
 
+  The following UDP discovery messages are defined in `p2p/src/main/proto/Discover.proto` in the java-tron repository.
+
   `Endpoint`: the storage structure of nodes' information.  
-  message`Endpoint` contains 3 parameters:  
-  `address`: the address of nodes.  
+  message`Endpoint` contains 4 parameters:  
+  `address`: the node's IPv4 address.  
   `port`: the port number.  
-  `nodeId`:the ID of nodes.
+  `nodeId`:the ID of nodes.  
+  `addressIpv6`: the node's IPv6 address.
 
 
       message Endpoint {
          bytes address = 1;
          int32 port = 2;
          bytes nodeId = 3;
+         bytes addressIpv6 = 4;
        }
 
-   `PingMessage`: the message sent from one node to another in the connecting process.  
+   `PingMessage`: a UDP request for node discovery and liveness checks.  
    message`PingMessage` contains 4 parameters:  
    `from`: which node does the message send from.  
    `to`: which node will the message send to.  
-   `version`: the version of the Internet.  
+   `version`: the sending node's network identifier (`networkId`).  
    `timestamp`: the timestamp of message.
 
        message PingMessage {
@@ -693,10 +697,10 @@ Input, transaction and head block all require signature.
          int64 timestamp = 4;
         }
 
-   `PongMessage`: the message implies that nodes are connected.  
+   `PongMessage`: a response to a UDP node discovery and liveness probe.  
    message`PongMessage` contains 3 parameters:  
    `from`: which node does the message send from.  
-   `echo`:  
+   `echo`: the responding node's network identifier (`networkId`).  
    `timestamp`: the timestamp of message.
 
         message PongMessage {
@@ -705,10 +709,10 @@ Input, transaction and head block all require signature.
           int64 timestamp = 3;
          }
 
-   `FindNeighbours`: the message sent from one node to find another one.  
+   `FindNeighbours`: a request for nodes closest to `targetId`.  
    message`FindNeighbours` contains 3 parameters:  
    `from`: which node does the message send from.  
-   `targetId`: the ID of targeted node.  
+   `targetId`: the target node ID used to find nearby nodes.  
    `timestamp`: the timestamp of message. 
 
         message FindNeighbours {
@@ -717,11 +721,11 @@ Input, transaction and head block all require signature.
           int64 timestamp = 3;
          }
 
-   `FindNeighbour`: the message replied by the neighbour node.  
+   `Neighbours`: a response to `FindNeighbours` containing nodes closest to `targetId`.  
     message`Neighbours` contains 3 parameters:  
     `from`: which node does the message send from.    
-    `neighbours`: the neighbour node.  
-    `timestamp`: the timestamp of message.
+    `neighbours`: the returned list of nodes.  
+    `timestamp`: the timestamp copied from the corresponding `FindNeighbours` request.
 
         message Neighbours {
           Endpoint from = 1;

protocol/src/main/protos/core/Discover.proto

@@ -13,32 +13,7 @@ message Endpoint {
   bytes addressIpv6 = 4;
 }
 
-message PingMessage {
-  Endpoint from = 1;
-  Endpoint to = 2;
-  int32 version = 3;
-  int64 timestamp = 4;
-}
-
-message PongMessage {
-  Endpoint from = 1;
-  int32 echo = 2;
-  int64 timestamp = 3;
-}
-
-message FindNeighbours {
-  Endpoint from = 1;
-  bytes targetId = 2;
-  int64 timestamp = 3;
-}
-
-message Neighbours {
-  Endpoint from = 1;
-  repeated Endpoint neighbours = 2;
-  int64 timestamp = 3;
-}
-
 message BackupMessage {
   bool flag = 1;
   int32 priority = 2;
-}
+}