在c + +中的貓鼬服務器

Question

我正在開發一個API服務器在c + + OOP中使用貓鼬庫我不斷收到錯誤有人可以看看我的代碼，並給我一些指針。 embServer.h

class embServer 
{ 

private: 
    constexpr static const char *s_http_port = "8000"; 
    constexpr static struct mg_serve_http_opts s_http_server_opts = { .document_root = "web_root" }; // C99; 
    static int s_sig_num; 
    constexpr static const struct mg_str s_get_method = MG_MK_STR("GET"); 
    constexpr static const struct mg_str s_put_method = MG_MK_STR("PUT"); 
    constexpr static const struct mg_str s_delele_method = MG_MK_STR("DELETE"); 


public: 
    embServer(); 
    ~embServer(); 

    Database dbConn; 
    //int embServer::s_sig_num = 0; 


    static void signal_handler(int sig_num) 
    { 
     signal(sig_num, signal_handler); 
     s_sig_num = sig_num; 
    } 

    static int has_prefix(const struct mg_str *uri, const struct mg_str *prefix) 
    { 
     return uri->len > prefix->len && memcmp(uri->p, prefix->p, prefix->len) == 0; 
    } 

    static int is_equal(const struct mg_str *s1, const struct mg_str *s2) 
    { 
     return s1->len == s2->len && memcmp(s1->p, s2->p, s2->len) == 0; 
    } 

    static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) 
    { 
     static const struct mg_str api_prefix = MG_MK_STR("/api/v1"); 
     struct http_message *hm = (struct http_message *) ev_data; 
     struct mg_str key; 

     switch (ev) 
     { 
     case MG_EV_HTTP_REQUEST: 

      if (has_prefix(&hm->uri, &api_prefix)) 
      { 
       key.p = hm->uri.p + api_prefix.len; 

       key.len = hm->uri.len - api_prefix.len; 

       if (embServer::is_equal(&hm->method, &s_get_method)) 
       { 
        //dbConn.db_op(nc, hm, &key, 1); 
       } 
       else if (embServer::is_equal(&hm->method, &s_put_method)) 
       { 
        //dbConn.db_op(nc, hm, &key, 2); 
       } 
       else if (embServer::is_equal(&hm->method, &s_delele_method)) 
       { 
        //dbConn.db_op(nc, hm, &key, 3); 
       } 
       else 
       { 
        mg_printf(nc, "%s","HTTP/1.0 501 Not Implemented\r\n" "Content-Length: 0\r\n\r\n"); 
       } 
      } 
      else 
      { 
       mg_serve_http(nc, hm, &s_http_server_opts); /* Serve static content */ 
      } 
      break; 
     default: 
      break; 
     } 
    } 

    void Run() 
    { 

     struct mg_mgr mgr; 
     struct mg_connection *nc; 
     //int i; 

     /* Open listening socket */ 
     mg_mgr_init(&mgr, NULL); 
     nc = mg_bind(&mgr, s_http_port, embServer::ev_handler); 
     mg_set_protocol_http_websocket(nc); 


     /* For each new connection, execute ev_handler in a separate thread */ 
     mg_enable_multithreading(nc); 



     /** 
     for (i = 1; i < argc; i++) 
     { 
      if (strcmp(argv[i], "-D") == 0) 
      { 
       mgr.hexdump_file = argv[++i]; 
      } 
      else if (strcmp(argv[i], "-f") == 0) 
      { 
       s_db_path = argv[++i]; 
      } 
      else if (strcmp(argv[i], "-r") == 0) 
      { 
       s_http_server_opts.document_root = argv[++i]; 
      } 
     } 
     Parse command line arguments */ 

     signal(SIGINT, &embServer::signal_handler); 
     signal(SIGTERM, &embServer::signal_handler); 

     /* Run event loop until signal is received */ 
     printf("Starting RESTful server on port %s\n", s_http_port); 
     while (s_sig_num == 0) 
     { 
      mg_mgr_poll(&mgr, 1000); 
     } 

     /* Cleanup */ 
     mg_mgr_free(&mgr); 
     printf("Exiting on signal %d\n", s_sig_num); 


    } 
}; 
int embServer::s_sig_num = 0; 

錯誤顯示

`F:\PROJECTS\CP\apiCrud\embServer.h|48|warning: variable 'key' set but not used [-Wunused-but-set-variable]| 
obj\Debug\main.o||In function `ZN9embServer10ev_handlerEP13mg_connectioniPv':| 
F:\PROJECTS\CP\apiCrud\embServer.h|79|undefined reference to `embServer::s_http_server_opts'| 
F:\PROJECTS\CP\apiCrud\embServer.h|79|undefined reference to `embServer::s_http_server_opts'| 
F:\PROJECTS\CP\apiCrud\embServer.h|79|undefined reference to `embServer::s_http_server_opts'| 
F:\PROJECTS\CP\apiCrud\embServer.h|79|undefined reference to `embServer::s_http_server_opts'| 
F:\PROJECTS\CP\apiCrud\embServer.h|79|undefined reference to `embServer::s_http_server_opts'| 
obj\Debug\main.o:F:\PROJECTS\CP\apiCrud\embServer.h|79|more undefined references to `embServer::s_http_server_opts' follow| 
obj\Debug\main.o||In function `main':| 
F:\PROJECTS\CP\apiCrud\main.cpp|15|undefined reference to `embServer::embServer()'| 
F:\PROJECTS\CP\apiCrud\main.cpp|15|undefined reference to `embServer::~embServer()'| 
F:\PROJECTS\CP\apiCrud\main.cpp|15|undefined reference to `embServer::~embServer()'| 
||error: ld returned 1 exit status| 
||=== Build failed: 10 error(s),(0 minute(s), 22 second(s)) ===|` 

int main(int argc, char *argv[]) 
{ 
    embServer emb; 
    emb.Run(); 

    return 0; 
} 

Answer 1

編譯器直接告訴你，你需要做這些改變：

1. 添加constexpr到static struct mg_serve_http_opts s_http_server_opts。
2. 從mg_serve_http(nc, hm, &s_http_server_opts)中刪除&。

Answer 2

是一個鏈接器錯誤。看起來你沒有實現析構函數，構造函數。 mg_serve_http_opts的實現也缺失。似乎你錯過了一些源文件（c/cpp）或者一些對象/庫。你必須用mongoose.c編譯應用程序。另外添加內聯或在單獨的文件中的ctor/dtor的實現。