使用 thrift c_glib 客户端未将结构返回给客户端

Structure not returned to client using thrift c_glib client

我正在尝试使用 thrift 在 c (c_glib) 中实现客户端/服务器程序。

我已经实现了将变量作为函数参数传递的客户端/服务器。现在我需要将结构作为函数参数传递。

下面给出了我正在使用的 thrift 文件

#!/usr/local/bin/thrift --gen c_glib


struct packet {
        1: i32 header,
        2: i32 data
}

service Calculator {
        void ping(),
        i32 calculate(1:i32 id, 2:i32 num),
        void stop_transfer(),
        void set_packet(1:packet pac_data)

}

我传递结构所遵循的步骤是:

客户端相关代码如下

int main (void) 
{
    gint head;
    gint dat;

    packet *trans_packet;

    trans_packet = g_object_new (TYPE_PACKET, NULL);

    if(!error && calculator_if_set_packet (client, trans_packet, &error)) {
        g_object_get((packet *) trans_packet,
             "header", &head,
             "data", &dat,
             NULL);

        printf("struct->header : %d\n", head);
        printf("struct->data : %d\n", dat);
    }

    g_object_unref (trans_packet);

}

服务端函数如下

static gboolean 
tutorial_calculator_handler_set_packet(CalculatorIf *iface,
                                  const packet * pac_data,
                                  GError **error)
{
    gint header;
    gint data;

    THRIFT_UNSED_VAR (iface);
    THRIFT_UNUSED_VAR (error);

    g_object_get((packet *) pac_data,
             "header", &header,
             "data", &data,
             NULL);

    g_object_set((packet *) pac_data,
             "header", 123,
             "data", 999,
             NULL);

    return TRUE;
}

执行此操作时,服务器在调用 calculator_if_set_packet() 时不会向客户端返回任何内容。

谁能帮我解决这个问题?

您显示的结构未使用 C 语法,即使对于位字段也是如此:

struct packet {  //Not C syntax
        1: i32 header, //1nvalid struct field declaration
        2: i32 data    //invalid struct field declaration
}                      //missing ;  

您没有显示将结构作为参数的函数原型,而是举例说明您的结构是这样定义的:

typedef struct {
    int header;
    int data;
} PACKET;  //symbol PACKET would be used like your "struct packet"

然后使用此 typedef,您可以创建一个实例,以及指向该结构的指针,如下所示:

PACKET 数据包,*pPacket;

在main中,可以使用实例来初始化指针,像这样:

int main(void)
{
    //pointer   instance
      pPacket = &packet;
      pPacket = malloc(sizeof(PACKET));//provide memory for pointer
      ...

      free(pPacket);//free dynamic memory 
      return 0;
}

然后,举例来说,你有一个函数原型接受一个实例,另一个函数原型接受一个指向该结构的指针:

void someFunc1(PACKET pkt);  // takes an instance of PACKET
void someFunc2(PACKET *pkt);  //takes an instance of PACKET *

然后在main中,可以这样pass then:

int main(void)
{
    pPacket = &packet;  //initialize pointer using instance
    pPacket = malloc(sizeof(PACKET));//provide memory for pointer

    someFunc1(packet);  //pass instance of PACKET
    someFunc2(pPacket); //pass pointer to PACKET
    someFunc2(&packet); //same as previous
    ...
    free(pPacket);//free dynamic memory 
    return 0;
}

我可以找到上述问题的解决方案。

我更改了 thrift 文件如下:

#!/usr/local/bin/thrift --gen c_glib

struct packet {
    1: i32 header,
    2: i32 data
}

service Calculator {
    void ping(),
    i32 calculate(1:i32 id, 2:i32 num),
    void stop_transfer(),
    packet set_packet(1:packet pac_data)
}

客户端和服务器部分相应修改如下:

在客户端

int main (void) 
{
    gint head;
    gint dat;

    packet *trans_packet;
    packet *ret_packet;

    trans_packet = g_object_new (TYPE_PACKET, NULL);
    ret_packet = g_object_new (TYPE_PACKET, NULL);

    if(!error && calculator_if_set_packet (client, &ret_packet, trans_packet, &error)) {
        g_object_get((packet *) ret_packet,
             "header", &head,
             "data", &dat,
             NULL);

        printf("struct->header : %d\n", head);
        printf("struct->data : %d\n", dat);
    }

    g_object_unref (trans_packet);
    g_object_unref (ret_packet);
}

在服务器部分

static gboolean 
tutorial_calculator_handler_set_packet(CalculatorIf *iface,
                              packet ** _return,
                              const packet * pac_data,
                              GError **error)
{
    gint header;
    gint data;

    THRIFT_UNSED_VAR (iface);
    THRIFT_UNUSED_VAR (error);

    g_object_get((packet *) pac_data,
             "header", &header,
             "data", &data,
             NULL);

    g_object_set(*_return,
             "header", 123,
             "data", 999,
             NULL);

    return TRUE;
}

现在无论我在服务器中设置什么,客户端都会得到它。

如果有任何其他解决方案,请更新答案。