typedef struct ProtocolExtensionConfig {
    bool    server_handshake_first;
    int     (*fn_accept)(pgsocket server_fd, struct Port *port);
    void    (*fn_close)(pgsocket server_fd);
    void    (*fn_init)(void);
    int     (*fn_start)(struct Port *port);
    void    (*fn_authenticate)(struct Port *port);
    void    (*fn_send_message)(ErrorData *edata);
    void    (*fn_send_cancel_key)(int32 pid, int32 key);
    void    (*fn_comm_reset)(void);
    void    (*fn_send_ready_for_query)(CommandDest dest);
    int	    (*fn_read_command)(StringInfo inBuf);
    void    (*fn_end_command)(const char *tag, CommandDest dest);
    DestReceiver*   (*fn_printtup_create_DR)(CommandDest dest);
    void    (*fn_set_DR_params)(DestReceiver* self, List* target_list);
    int     (*fn_process_command)(StringInfo inBuf);
    void    (*fn_report_param_status)(const char *name, char *val);
} ProtocolExtensionConfig;

ProtocolExtensionConfig default_protocol_config = {
    false,
    StreamConnection,
    StreamClose,
    pq_init,
    StartupPacketInitialize,
    ClientAuthentication,
    send_message_to_frontend,
    libpq_send_cancel_key,
    pq_comm_reset,
    ReadyForQuery,
    SocketBackend,
    EndCommand,
    printtup_create_DR,
    NULL,
    NULL,
    libpq_report_param_status
};

src/common/backend/libpq/pqcomm.cpp                        |  25 ++++++++-----
  => 创建监听端口时，绑定网络协议扩展配置
src/common/backend/utils/error/elog.cpp                    |   9 +++--
  => 适配send_message_to_frontend
src/common/backend/utils/init/postinit.cpp                 |  11 +++---
  => 适配ClientAuthentication
src/common/backend/utils/misc/guc.cpp                      |  15 +++-----
  => 适配 report_param_status
src/gausskernel/process/postmaster/postmaster.cpp          | 227 +++++++++++++-----
  => 增加全局的协议扩展配置，定义opengauss默认网络协议实现，支持动态刷新监听的fd
src/gausskernel/process/tcop/dest.cpp                      |   2 +-
  => 适配 printtup_create_DR
src/gausskernel/process/tcop/postgres.cpp                  |  71 +++++++++++++++++++++--------------
  => 适配EndCommand,read_command,send_cancel_key, comm_reset, send_ready_for_query, process_command
src/gausskernel/process/threadpool/knl_thread.cpp          |   1 -
  =>移动ListenContext相关变量至g_instance中
src/gausskernel/process/threadpool/threadpool_listener.cpp |  6 ++++-
  => epoll中增加写事件，兼容由server端发起握手的数据库网络协议
src/gausskernel/process/threadpool/threadpool_worker.cpp   |  14 +++----
  => 适配send_ready_for_query, send_cancel_key
src/gausskernel/runtime/executor/spi.cpp                   |   9 ++++-
  => spi中兼容dolphin事务处理, 增加printtup需要的stmt参数透传
src/include/access/printtup.h                              |   1 +
  => DR_printtup增加target_list, 用于通过spi输出数据报文header到客户端
src/include/knl/knl_instance.h                             |  12 ++++++
  => 增加knl_g_listen_context结构体，用于运行时动态修改监听端口信息
src/include/knl/knl_thread.h                               |  7 +++---
  => 移动listen_context相关的属性至knl_instance.h
src/include/libpq/libpq-be.h                               |  28 ++++++++++++++
  => 定义ProtocolExtensionConfig接口，Port结构体中增加protocol_config属性
src/include/libpq/libpq.h                                  |   6 ++-
  => StreamServerPort中增加ProtocolExtensionConfig*参数
src/include/catalog/pg_authid.h                            |   6 +++++-
  => authid系统表中增加rolepasswordext，用于保存dolphin格式的密码
  

17 files changed, 291 insertions(+), 160 deletions(-)

protocol->fn_accept(serverFd, port) != STATUS_OK

protocol->fn_close(port->sock);

if (port->protocol_config && port->protocol_config->fn_init) {
    port->protocol_config->fn_init(); 
} else {
    pq_init();
}

int status = port->protocol_config->fn_start(port);

port->protocol_config->fn_authenticate(port);

void send_message_to_frontend_ext(ErrorData* edata) {
    if (u_sess->proc_cxt.MyProcPort) {
        u_sess->proc_cxt.MyProcPort->protocol_config->fn_send_message(edata);
    }
}

Port* MyProcPort = u_sess->proc_cxt.MyProcPort;
if (MyProcPort && MyProcPort->protocol_config->fn_send_cancel_key) {
    MyProcPort->protocol_config->fn_send_cancel_key((int32)t_thrd.proc_cxt.MyPMChildSlot,
                                                            (int32)t_thrd.proc_cxt.MyCancelKey);
}

extern void libpq_send_cancel_key(int32 pid, int32 key);
void libpq_send_cancel_key(int32 pid, int32 key)
{
    StringInfoData buf;

    pq_beginmessage(&buf, 'K');
    pq_sendint32(&buf, pid);
    pq_sendint32(&buf, key);
    pq_endmessage(&buf);
}

Port* MyProcPort = u_sess->proc_cxt.MyProcPort;
if (MyProcPort && MyProcPort->protocol_config->fn_comm_reset) {
    MyProcPort->protocol_config->fn_comm_reset();
}

session->proc_cxt.MyProcPort->protocol_config->fn_send_ready_for_query((CommandDest)t_thrd.postgres_cxt.whereToSendOutput);

result = u_sess->proc_cxt.MyProcPort->protocol_config->fn_read_command(inBuf);

void EndCommandExt(const char *completionTag, CommandDest dest) {
    Port* MyProcPort = u_sess->proc_cxt.MyProcPort;
    if (MyProcPort) {
        MyProcPort->protocol_config->fn_end_command(completionTag, dest);
    }
}

u_sess->proc_cxt.MyProcPort->protocol_config->fn_printtup_create_DR(dest);

/*
 * ReportGUCOption: if appropriate, transmit option value to frontend
 */
static void ReportGUCOption(struct config_generic* record)
{
    if (u_sess->utils_cxt.reporting_enabled && (record->flags & GUC_REPORT)) {
        Port* MyProcPort = u_sess->proc_cxt.MyProcPort;
        if (MyProcPort && MyProcPort->protocol_config->fn_report_param_status) {
            char* val = _ShowOption(record, false);
            (MyProcPort->protocol_config->fn_report_param_status)(record->name, val);
            pfree(val);
        }
    }
}

void libpq_report_param_status(const char *name, char *val)
{
    StringInfoData msgbuf;

    pq_beginmessage(&msgbuf, 'S');
    pq_sendstring(&msgbuf, name);
    pq_sendstring(&msgbuf, val);
    pq_endmessage(&msgbuf);
}