fix(dbms): put EOT char in the end of request/response

tdbms/client/tdbms-client.c

@@ -57,6 +57,7 @@ char *tdb_query(int socket_fd, const char *db_name, char request_code, const cha
         buffer += nwrite;
         req_size -= nwrite;
         if (req_size == 0) {
+            nwrite = write(socket_fd, "\4", 1);
             break;
         }
     }
@@ -75,7 +76,7 @@ char *tdb_query(int socket_fd, const char *db_name, char request_code, const cha
         }
         memcpy(response + offset, buffer, nread);
         offset += nread;
-        if (response[offset - 1] == 0) {
+        if (response[offset - 1] == EOT) {
             break;
         }
     }

tdbms/server/tdbms-server.c

@@ -836,7 +836,7 @@ void *client_thread(void *arg) {
                 }
                 memcpy(request + offset, buffer, nread);
                 offset += nread;
-                if (request[offset - 1] == 0) {
+                if (request[offset - 1] == EOT) {
                     break;
                 }
             }
@@ -860,6 +860,7 @@ void *client_thread(void *arg) {
                     buf += nwrite;
                     resp_size -= nwrite;
                     if (resp_size == 0) {
+                        nwrite = write(client_fd, "\4", 1);
                         break;
                     }
                 }