observer可以直接在控制台输入命令 (#199)

### What problem were solved in this pull request?

Issue Number: close #162 

Problem:
当前的observer启动流程和调试方法比较繁琐，必须使用客户端服务端的方式，先启动服务端程序，再使用客户端启动调试

### What is changed and how it works?
observer可以直接启动，不监听tcp或unix socket，直接通过终端/控制台输入命令并执行，极大的方便了调试

### Other information
新的启动方法：
./bin/observer -P cli -f ../etc/observer.ini

.github/workflows/build.yml

@@ -64,4 +64,5 @@ jobs:
         shell: bash
         run: |
           sudo bash build.sh init
+          echo "begin test..."
           python3 test/case/miniob_test.py --test-cases=basic | tail -1 | grep "basic is success"

CMakeLists.txt

-# include 另外一个cmake 配置
-#INCLUDE(file1 [OPTIONAL])
-
 cmake_minimum_required(VERSION 3.10)
 set(CMAKE_CXX_STANDARD 20)
-#SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 
 project(minidb)
 
-MESSAGE(STATUS "This is SOURCE dir " ${test_SOURCE_DIR})
-MESSAGE(STATUS "This is BINARY dir " ${test_BINARY_DIR})
 MESSAGE(STATUS "This is Project source dir " ${PROJECT_SOURCE_DIR})
 MESSAGE(STATUS "This is PROJECT_BINARY_DIR dir " ${PROJECT_BINARY_DIR})
 
 SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
-#SET(LIBRARY_OUTPUT_PATH <路径>)
 
-OPTION(ENABLE_ASAN "Enable build with address sanitizer" OFF)
+SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
+
+OPTION(ENABLE_ASAN "Enable build with address sanitizer" ON)
 OPTION(WITH_UNIT_TESTS "Compile miniob with unit tests" ON)
 OPTION(CONCURRENCY "Support concurrency operations" OFF)
 
@@ -77,6 +72,21 @@ ELSE()
 ENDIF()
 MESSAGE("Install target dir is " ${CMAKE_INSTALL_PREFIX})
 
+IF (DEFINED ENV{LD_LIBRARY_PATH})
+    SET(LD_LIBRARY_PATH_STR $ENV{LD_LIBRARY_PATH})
+    string(REPLACE ":" ";" LD_LIBRARY_PATH_LIST ${LD_LIBRARY_PATH_STR})
+    MESSAGE(" Add LD_LIBRARY_PATH to -L flags " ${LD_LIBRARY_PATH_LIST})
+    LINK_DIRECTORIES(${LD_LIBRARY_PATH_LIST})
+ENDIF ()
+
+IF (EXISTS /usr/local/lib)
+    LINK_DIRECTORIES (/usr/local/lib)
+ENDIF ()
+IF (EXISTS /usr/local/lib64)
+    LINK_DIRECTORIES (/usr/local/lib64)
+ENDIF ()
+
+INCLUDE_DIRECTORIES(. ${PROJECT_SOURCE_DIR}/deps /usr/local/include)
 
 # ADD_SUBDIRECTORY(src bin)  bin 为目标目录， 可以省略
 ADD_SUBDIRECTORY(deps)
@@ -91,16 +101,6 @@ IF(WITH_UNIT_TESTS)
     ADD_SUBDIRECTORY(unittest)
 ENDIF()
 
-# install 准备安装的目录是cmakefile 的当前目录， 不是build 后生成的目录
-# Files 默认权限OWNER_WRITE, OWNER_READ, GROUP_READ,和WORLD_READ，即644权限
-# INSTALL(FILES docs/README DESTINATION ./  )
-# INSTALL(DIRECTORY docs DESTINATION ./
-#        PATTERN "README" EXCLUDE)
-#  PERMISSIONS 可以直接替换
-#INSTALL(DIRECTORY bin DESTINATION ./
-#        FILE_PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ GROUP_EXECUTE GROUP_READ WORLD_READ
-#        DIRECTORY_PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ GROUP_EXECUTE GROUP_READ WORLD_READ WORLD_EXECUTE)
-
 INSTALL(DIRECTORY etc DESTINATION .
 		FILE_PERMISSIONS OWNER_WRITE OWNER_READ GROUP_READ WORLD_READ)
 
@@ -113,11 +113,6 @@ INSTALL(CODE "MESSAGE(\"Sample install message.\")")
 #        [ARGS <arguments to executable>]
 #        [OUTPUT_VARIABLE <var>]
 
-
-
-
-# ADD_TEST与ENABLE_TESTING 参考书籍
-
 #EXEC_PROGRAM(Executable [directory in which to run]
 #        [ARGS <arguments to executable>]
 #        [OUTPUT_VARIABLE <var>]

README.md

@@ -8,12 +8,13 @@ MiniOB 设计的目标是面向在校学生、数据库从业者、爱好者，
 
 为了帮助开发者更好的上手并学习 miniob, 建议阅读：
 
-1. [miniob 框架介绍](docs/miniob-introduction.md)
-2. [如何编译 MiniOB 源码](docs/how_to_build.md)
-3. [使用 GitPod 开发 MiniOB](docs/dev_by_gitpod.md)
-4. [开发环境搭建(本地调试, 适用 Linux 和 Mac)](docs/how_to_dev_miniob_by_vscode.md)
-5. [开发环境搭建(远程调试, 适用于 Window, Linux 和 Mac)](docs/how_to_dev_in_docker_container_by_vscode.md)
-6. [MiniOB 词法语法解析开发与测试](docs/miniob-sql-parser.md)
+1. [miniob 框架介绍](docs/src/miniob-introduction.md)
+2. [如何编译 MiniOB 源码](docs/src/how_to_build.md)
+3. [如何运行 MiniOB](docs/src/how_to_run.md)
+3. [使用 GitPod 开发 MiniOB](docs/src/dev-env/dev_by_gitpod.md)
+4. [开发环境搭建(本地调试, 适用 Linux 和 Mac)](docs/src/dev-env/how_to_dev_miniob_by_vscode.md)
+5. [开发环境搭建(远程调试, 适用于 Window, Linux 和 Mac)](docs/src/dev-env/how_to_dev_in_docker_container_by_vscode.md)
+6. [MiniOB 各模块文档](docs/src/design/introduction.md)
 7. [doxygen 代码文档](docs/doxy/html/index.html)
 
 或者直接看 [MiniOB GitHub Pages](https://oceanbase.github.io/miniob/).

benchmark/CMakeLists.txt

-PROJECT(benchmark)
-MESSAGE("Begin to build " ${PROJECT_NAME})
-MESSAGE(STATUS "This is PROJECT_BINARY_DIR dir " ${PROJECT_BINARY_DIR})
-MESSAGE(STATUS "This is PROJECT_SOURCE_DIR dir " ${PROJECT_SOURCE_DIR})
-
-# 可以获取父cmake的变量
-MESSAGE("${CMAKE_COMMON_FLAGS}")
-
-#INCLUDE_DIRECTORIES([AFTER|BEFORE] [SYSTEM] dir1 dir2 ...)
-INCLUDE_DIRECTORIES(. ${PROJECT_SOURCE_DIR}/../deps ${PROJECT_SOURCE_DIR}/../src/observer /usr/local/include SYSTEM)
-# 父cmake 设置的include_directories 和link_directories并不传导到子cmake里面
-#INCLUDE_DIRECTORIES(BEFORE ${CMAKE_INSTALL_PREFIX}/include)
-LINK_DIRECTORIES(/usr/local/lib /usr/local/lib64 ${PROJECT_BINARY_DIR}/../lib)
-
-IF (DEFINED ENV{LD_LIBRARY_PATH})
-    SET(LD_LIBRARY_PATH_STR $ENV{LD_LIBRARY_PATH})
-    #separate_arguments(LD_LIBRARY_PATH_STR)  #只能处理空行
-    string(REPLACE ":" ";" LD_LIBRARY_PATH_LIST ${LD_LIBRARY_PATH_STR})
-    MESSAGE(" Add LD_LIBRARY_PATH to -L flags " ${LD_LIBRARY_PATH_LIST})
-    LINK_DIRECTORIES(${LD_LIBRARY_PATH_LIST})
-ELSE ()
-    LINK_DIRECTORIES(/usr/local/lib)
-ENDIF ()
-
 find_package(benchmark CONFIG REQUIRED)
 
+INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR}/src/observer)
+
 FILE(GLOB_RECURSE ALL_SRC *.cpp)
 # AUX_SOURCE_DIRECTORY 类似功能
 FOREACH (F ${ALL_SRC})
@@ -32,4 +10,3 @@ FOREACH (F ${ALL_SRC})
     ADD_EXECUTABLE(${prjName} ${F})
     TARGET_LINK_LIBRARIES(${prjName} common pthread dl benchmark observer_static)
 ENDFOREACH (F)
-

cmake/readline.cmake

+
+MACRO (MINIOB_FIND_READLINE)
+
+  FIND_PATH(READLINE_INCLUDE_DIR readline.h PATH_SUFFIXES readline)
+  FIND_LIBRARY(READLINE_LIBRARY NAMES readline)
+  IF (READLINE_INCLUDE_DIR AND READLINE_LIBRARY)
+    SET(HAVE_READLINE 1)
+  ELSE ()
+    MESSAGE("cannot find readline")
+  ENDIF()
+
+ENDMACRO (MINIOB_FIND_READLINE)

deps/CMakeLists.txt

 
-
 ADD_SUBDIRECTORY(common)

deps/common/CMakeLists.txt

 MESSAGE(STATUS "This is PROJECT_BINARY_DIR dir " ${PROJECT_BINARY_DIR})
 MESSAGE(STATUS "This is PROJECT_SOURCE_DIR dir " ${PROJECT_SOURCE_DIR})
 
-INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR} ${PROJECT_SOURCE_DIR}/deps)
+INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
 
 FILE(GLOB_RECURSE ALL_SRC  *.cpp)
 FOREACH(F ${ALL_SRC})

deps/common/seda/stage.h

@@ -205,7 +205,7 @@ public:
 
   /**
    * Perform Stage-specific processing for an event
-   * Processing one event without swtich thread.
+   * Processing one event without switch thread.
    * Handle the event according to requirements of specific stage.  Pure
    * virtual member function.
    *
@@ -222,7 +222,8 @@ public:
    *
    * @param[in] event Pointer to event that initiated the callback.
    */
-  virtual void callback_event(StageEvent *event, CallbackContext *context) = 0;
+  virtual void callback_event(StageEvent *event, CallbackContext *context)
+  {}
 
   /**
    * Perform Stage-specific callback processing for a timed out event

docs/src/SUMMARY.md

@@ -2,6 +2,7 @@
 
 - [MiniOB 简介](./miniob-introduction.md)
 - [如何编译](./how_to_build.md)
+- [如何运行](./how_to_run.md)
 - [开发环境搭建](./dev-env/introduction.md)
   - [使用 GitPod 开发 MiniOB](./dev-env/dev_by_gitpod.md)
   - [开发环境搭建(本地调试, 适用 Linux 和 Mac)](./dev-env/how_to_dev_miniob_by_vscode.md)

docs/src/how_to_run.md

+# 如何运行
+
+编译完成后，可以在build目录（可能是build_debug或build_release）下找到bin/observer，就是我们的服务端程序，bin/obclient是自带的客户端程序。
+当前服务端程序启动已经支持了多种模式，可以以TCP、unix socket方式启动，这时需要启动客户端以发起命令。observer还支持直接执行命令的模式，这时不需要启动客户端，直接在命令行输入命令即可。
+
+**以直接执行命令的方式启动服务端程序**
+```bash
+./bin/observer -f ../etc/observer.ini -P cli
+```
+这会以直接执行命令的方式启动服务端程序，可以直接输入命令，不需要客户端。所有的请求都会以单线程的方式运行，配置项中的线程数不再有实际意义。
+
+**以监听TCP端口的方式启动服务端程序**
+
+```bash
+./bin/observer -f ../etc/observer.ini -p 6789
+```
+这会以监听6789端口的方式启动服务端程序。
+启动客户端程序：
+```bash
+./bin/obclient -p 6789
+```
+这会连接到服务端的6789端口。
+
+**以监听unix socket的方式启动服务端程序**
+```bash
+./bin/observer -f ../etc/observer.ini -s miniob.sock
+```
+这会以监听unix socket的方式启动服务端程序。
+启动客户端程序：
+```bash
+./bin/obclient -s miniob.sock
+```
+这会连接到服务端的miniob.sock文件。
+
+**更多**
+observer还提供了一些其它参数，可以通过./bin/observer -h查看。

src/CMakeLists.txt

-PROJECT(miniob)
-MESSAGE("Begin to build " ${PROJECT_NAME})
-MESSAGE(STATUS "This is PROJECT_BINARY_DIR dir " ${PROJECT_BINARY_DIR})
-MESSAGE(STATUS "This is PROJECT_SOURCE_DIR dir " ${PROJECT_SOURCE_DIR})
-
-
-ADD_SUBDIRECTORY(obclient)
-ADD_SUBDIRECTORY(observer)
-
-
-
-
-

src/obclient/CMakeLists.txt

 ADD_EXECUTABLE(obclient)
 MESSAGE("Begin to build " obclient)
 
-INCLUDE(CheckIncludeFiles)
+INCLUDE(readline)
+MINIOB_FIND_READLINE()
 
-#INCLUDE_DIRECTORIES([AFTER|BEFORE] [SYSTEM] dir1 dir2 ...)
-TARGET_INCLUDE_DIRECTORIES(obclient PRIVATE . ${PROJECT_SOURCE_DIR}/deps /usr/local/include /usr/include)
-# 父cmake 设置的include_directories 和link_directories并不传导到子cmake里面
-#INCLUDE_DIRECTORIES(BEFORE ${CMAKE_INSTALL_PREFIX}/include)
-
-# stdio.h 必须放在readline/readline.h 前面，因为readline头文件不能直接单独编译
-CHECK_INCLUDE_FILES("stdio.h;readline/readline.h" HAVE_READLINE_HEADER)
-
-FIND_LIBRARY(READLINE_LIBRARY readline)
-IF (HAVE_READLINE_HEADER AND READLINE_LIBRARY)
+IF (HAVE_READLINE)
     TARGET_LINK_LIBRARIES(obclient ${READLINE_LIBRARY})
+    TARGET_INCLUDE_DIRECTORIES(obclient PRIVATE ${READLINE_INCLUDE_DIR})
     ADD_DEFINITIONS(-DUSE_READLINE)
+    MESSAGE ("obclient use readline")
 ELSE ()
     MESSAGE ("readline is not found")
 ENDIF()
@@ -27,13 +21,9 @@ FOREACH (F ${ALL_SRC})
 
 ENDFOREACH (F)
 
-# 指定目标文件位置
-SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
-MESSAGE("Binary directory:" ${EXECUTABLE_OUTPUT_PATH})
 TARGET_SOURCES(obclient PRIVATE ${PRJ_SRC})
 TARGET_LINK_LIBRARIES(obclient common pthread dl)
 
-
 # Target 必须在定义 ADD_EXECUTABLE 之后， programs 不受这个限制
 # TARGETS和PROGRAMS 的默认权限是OWNER_EXECUTE, GROUP_EXECUTE, 和WORLD_EXECUTE，即755权限， programs 都是处理脚步类
 # 类型分为RUNTIME／LIBRARY／ARCHIVE, prog

src/obclient/client.cpp

@@ -75,7 +75,7 @@ char *my_readline(const char *prompt)
     fprintf(stderr, "failed to alloc line buffer");
     return nullptr;
   }
-  fprintf(stdout, prompt);
+  fprintf(stdout, "%s", prompt);
   char *s = fgets(buffer, MAX_MEM_BUFFER_SIZE, stdin);
   if (nullptr == s) {
     fprintf(stderr, "failed to read message from console");

src/observer/CMakeLists.txt

 MESSAGE(STATUS "This is CMAKE_CURRENT_SOURCE_DIR dir " ${CMAKE_CURRENT_SOURCE_DIR})
 
-INCLUDE_DIRECTORIES(. ${CMAKE_CURRENT_SOURCE_DIR} ${PROJECT_SOURCE_DIR}/deps /usr/local/include)
-LINK_DIRECTORIES(/usr/local/lib)
+INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
 
 FILE(GLOB_RECURSE ALL_SRC *.cpp *.c)
 SET(MAIN_SRC main.cpp)
@@ -33,6 +32,17 @@ ADD_EXECUTABLE(observer ${MAIN_SRC})
 TARGET_LINK_LIBRARIES(observer observer_static)
 
 ADD_LIBRARY(observer_static STATIC ${LIB_SRC})
+INCLUDE (readline)
+MINIOB_FIND_READLINE()
+IF (HAVE_READLINE)
+    TARGET_LINK_LIBRARIES(observer_static ${READLINE_LIBRARY})
+    TARGET_INCLUDE_DIRECTORIES(observer_static PRIVATE ${READLINE_INCLUDE_DIR})
+    ADD_DEFINITIONS(-DUSE_READLINE)
+    MESSAGE ("observer_static use readline")
+ELSE ()
+    MESSAGE ("readline is not found")
+ENDIF()
+
 SET_TARGET_PROPERTIES(observer_static PROPERTIES OUTPUT_NAME observer)
 TARGET_LINK_LIBRARIES(observer_static ${LIBRARIES})
 

src/observer/common/rc.h

@@ -16,6 +16,7 @@ See the Mulan PSL v2 for more details. */
 
 /**
  * @brief 这个文件定义函数返回码/错误码(Return Code)
+ * @enum RC
  */
 
 #define DEFINE_RCS                          \

src/observer/main.cpp

@@ -38,7 +38,7 @@ void usage()
   std::cout << "-p: server port. if not specified, the item in the config file will be used" << std::endl;
   std::cout << "-f: path of config file." << std::endl;
   std::cout << "-s: use unix socket and the argument is socket address" << std::endl;
-  std::cout << "-P: protocol. {plain(default), mysql}." << std::endl;
+  std::cout << "-P: protocol. {plain(default), mysql, cli}." << std::endl;
   std::cout << "-t: transaction model. {vacuous(default), mvcc}." << std::endl;
   std::cout << "-n: buffer pool memory size in byte" << std::endl;
   exit(0);
@@ -75,9 +75,6 @@ void parse_parameter(int argc, char **argv)
       case 'e':
         process_param->set_std_err(optarg);
         break;
-      case 'd':
-        process_param->set_demon(true);
-        break;
       case 't':
         process_param->set_trx_kit_name(optarg);
         break;
@@ -131,11 +128,14 @@ Server *init_server()
   server_param.port = port;
   if (0 == strcasecmp(process_param->get_protocol().c_str(), "mysql")) {
     server_param.protocol = CommunicateProtocol::MYSQL;
+  } else if (0 == strcasecmp(process_param->get_protocol().c_str(), "cli")) {
+    server_param.use_std_io = true;
+    server_param.protocol = CommunicateProtocol::CLI;
   } else {
     server_param.protocol = CommunicateProtocol::PLAIN;
   }
 
-  if (process_param->get_unix_socket_path().size() > 0) {
+  if (process_param->get_unix_socket_path().size() > 0 && !server_param.use_std_io) {
     server_param.use_unix_socket = true;
     server_param.unix_socket_path = process_param->get_unix_socket_path();
   }
@@ -166,13 +166,14 @@ void quit_signal_handle(int signum)
 
 int main(int argc, char **argv)
 {
+  int rc = STATUS_SUCCESS;
+
   setSignalHandler(quit_signal_handle);
 
   parse_parameter(argc, argv);
 
-  int rc = STATUS_SUCCESS;
   rc = init(the_process_param());
-  if (rc) {
+  if (rc != STATUS_SUCCESS) {
     std::cerr << "Shutdown due to failed to init!" << std::endl;
     cleanup();
     return rc;

src/observer/net/buffered_writer.cpp

@@ -43,10 +43,7 @@ RC BufferedWriter::close()
     return rc;
   }
 
-  if (fd_ >= 0) {
-    ::close(fd_);
-    fd_ = -1;
-  }
+  fd_ = -1;
 
   return RC::SUCCESS;
 }

src/observer/net/cli_communicator.cpp

+/* Copyright (c) 2021 OceanBase and/or its affiliates. All rights reserved.
+miniob is licensed under Mulan PSL v2.
+You can use this software according to the terms and conditions of the Mulan PSL v2.
+You may obtain a copy of Mulan PSL v2 at:
+         http://license.coscl.org.cn/MulanPSL2
+THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+See the Mulan PSL v2 for more details. */
+
+//
+// Created by Wangyunlai on 2023/06/25.
+//
+
+#include "net/cli_communicator.h"
+#include "net/buffered_writer.h"
+#include "common/log/log.h"
+#include "common/lang/string.h"
+#include "event/session_event.h"
+
+#ifdef USE_READLINE
+#include "readline/readline.h"
+#include "readline/history.h"
+#endif
+
+#define MAX_MEM_BUFFER_SIZE 8192
+#define PORT_DEFAULT 6789
+
+using namespace common;
+
+#ifdef USE_READLINE
+const std::string HISTORY_FILE = std::string(getenv("HOME")) + "/.miniob.history";
+time_t last_history_write_time = 0;
+
+char *my_readline(const char *prompt) 
+{
+  int size = history_length;
+  if (size == 0) {
+    read_history(HISTORY_FILE.c_str());
+
+    FILE *fp = fopen(HISTORY_FILE.c_str(), "a");
+    if (fp != nullptr) {
+      fclose(fp);
+    }
+  }
+
+  char *line = readline(prompt);
+  if (line != nullptr && line[0] != 0) {
+    add_history(line);
+    if (time(NULL) - last_history_write_time > 5) {
+      write_history(HISTORY_FILE.c_str());
+    }
+    // append_history doesn't work on some readlines
+    // append_history(1, HISTORY_FILE.c_str());
+  }
+  return line;
+}
+#else // USE_READLINE
+char *my_readline(const char *prompt)
+{
+  char *buffer = (char *)malloc(MAX_MEM_BUFFER_SIZE);
+  if (nullptr == buffer) {
+    LOG_WARN("failed to alloc line buffer");
+    return nullptr;
+  }
+  fprintf(stdout, "%s", prompt);
+  char *s = fgets(buffer, MAX_MEM_BUFFER_SIZE, stdin);
+  if (nullptr == s) {
+    free(buffer);
+    if (ferror(stdin) || feof(stdin)) {
+      LOG_WARN("failed to read line: %s", strerror(errno));
+    }
+    return nullptr;
+  }
+  return buffer;
+}
+#endif // USE_READLINE
+
+/* this function config a exit-cmd list, strncasecmp func truncate the command from terminal according to the number,
+   'strncasecmp("exit", cmd, 4)' means that obclient read command string from terminal, truncate it to 4 chars from 
+   the beginning, then compare the result with 'exit', if they match, exit the obclient.
+*/
+bool is_exit_command(const char *cmd) {
+  return 0 == strncasecmp("exit", cmd, 4) ||
+         0 == strncasecmp("bye", cmd, 3) ||
+         0 == strncasecmp("\\q", cmd, 2) ;
+}
+
+char *read_command()
+{
+  const char *prompt_str = "miniob > ";
+  char *input_command = nullptr;
+  for (input_command = my_readline(prompt_str); 
+        common::is_blank(input_command); 
+        input_command = my_readline(prompt_str)) {
+    free(input_command);
+    input_command = nullptr;
+  }
+  return input_command;
+}
+
+RC CliCommunicator::init(int fd, Session *session, const std::string &addr)
+{
+  RC rc = PlainCommunicator::init(fd, session, addr);
+  if (OB_FAIL(rc)) {
+    LOG_WARN("fail to init communicator", strrc(rc));
+    return rc;
+  }
+
+  if (fd == STDIN_FILENO) {
+    write_fd_ = STDOUT_FILENO;
+    delete writer_;
+    writer_ = new BufferedWriter(write_fd_);
+
+    const char delimiter = '\n';
+    send_message_delimiter_.assign(1, delimiter);
+
+    fd_ = -1; // 防止被父类析构函数关闭
+  } else {
+    rc = RC::INVALID_ARGUMENT;
+    LOG_WARN("only stdin supported");
+  }
+  return rc;
+}
+
+RC CliCommunicator::read_event(SessionEvent *&event)
+{
+  event = nullptr;
+  char *command = read_command();
+
+  if (is_exit_command(command)) {
+    free(command);
+    event = nullptr;
+    return RC::SUCCESS;
+  }
+
+  event = new SessionEvent(this);
+  event->set_query(std::string(command));
+  free(command);
+  return RC::SUCCESS;
+}
+
+RC CliCommunicator::write_result(SessionEvent *event, bool &need_disconnect)
+{
+  RC rc = PlainCommunicator::write_result(event, need_disconnect);
+  need_disconnect = false;
+  return rc;
+}

src/observer/net/cli_communicator.h

+/* Copyright (c) 2021 OceanBase and/or its affiliates. All rights reserved.
+miniob is licensed under Mulan PSL v2.
+You can use this software according to the terms and conditions of the Mulan PSL v2.
+You may obtain a copy of Mulan PSL v2 at:
+         http://license.coscl.org.cn/MulanPSL2
+THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+See the Mulan PSL v2 for more details. */
+
+//
+// Created by Wangyunlai on 2023/06/25.
+//
+
+#pragma once
+
+#include "net/plain_communicator.h"
+
+/**
+ * @brief 用于命令行模式的通讯器
+ * @ingroup Communicator
+ * @details 直接通过终端/标准输入输出进行通讯。从这里的实现来看，是不需要libevent的一些实现的，
+ * 因此communicator需要重构，或者需要重构server中的各个通讯启动模式。
+ */
+class CliCommunicator : public PlainCommunicator
+{
+public:
+  CliCommunicator() = default;
+  virtual ~CliCommunicator() = default;
+
+  RC init(int fd, Session *session, const std::string &addr) override;
+  RC read_event(SessionEvent *&event) override;
+  RC write_result(SessionEvent *event, bool &need_disconnect) override;
+
+private:
+  int write_fd_ = -1; ///< 与使用远程通讯模式不同，如果读数据使用标准输入，那么输出应该是标准输出
+};

src/observer/net/communicator.cpp

@@ -14,13 +14,13 @@ See the Mulan PSL v2 for more details. */
 
 #include "net/communicator.h"
 #include "net/mysql_communicator.h"
+#include "net/plain_communicator.h"
+#include "net/cli_communicator.h"
 #include "net/buffered_writer.h"
-#include "sql/expr/tuple.h"
-#include "event/session_event.h"
-#include "common/lang/mutex.h"
-#include "common/io/io.h"
 #include "session/session.h"
 
+#include "common/lang/mutex.h"
+
 RC Communicator::init(int fd, Session *session, const std::string &addr)
 {
   fd_ = fd;
@@ -47,254 +47,6 @@ Communicator::~Communicator()
   }
 }
 
-/////////////////////////////////////////////////////////////////////////////////
-RC PlainCommunicator::read_event(SessionEvent *&event)
-{
-  RC rc = RC::SUCCESS;
-
-  event = nullptr;
-
-  int data_len = 0;
-  int read_len = 0;
-
-  const int max_packet_size = 8192;
-  std::vector<char> buf(max_packet_size);
-
-  // 持续接收消息，直到遇到'\0'。将'\0'遇到的后续数据直接丢弃没有处理，因为目前仅支持一收一发的模式
-  while (true) {
-    read_len = ::read(fd_, buf.data() + data_len, max_packet_size - data_len);
-    if (read_len < 0) {
-      if (errno == EAGAIN) {
-        continue;
-      }
-      break;
-    }