extern "C" 與 __cplusplus 安全使用
阿新 • • 發佈：2019-01-10
無意中看原始碼看到的程式碼風格 如果已經巨集定義 __cplusplus 則加入extern "C" 檔案目錄為/usr/include/event2/http_struct.h
#ifndef _EVENT2_HTTP_STRUCT_H_ #define _EVENT2_HTTP_STRUCT_H_ /** @file event2/http_struct.h Data structures for http. Using these structures may hurt forward compatibility with later versions of Libevent: be careful! */ #ifdef __cplusplus extern "C" { #endif #include <event2/event-config.h> #ifdef _EVENT_HAVE_SYS_TYPES_H #include <sys/types.h> #endif #ifdef _EVENT_HAVE_SYS_TIME_H #include <sys/time.h> #endif /* For int types. */ #include <event2/util.h> /** * the request structure that a server receives. * WARNING: expect this structure to change. I will try to provide * reasonable accessors. */ struct evhttp_request { #if defined(TAILQ_ENTRY) TAILQ_ENTRY(evhttp_request) next; #else struct { struct evhttp_request *tqe_next; struct evhttp_request **tqe_prev; } next; #endif /* the connection object that this request belongs to */ struct evhttp_connection *evcon; int flags; /** The request obj owns the evhttp connection and needs to free it */ #define EVHTTP_REQ_OWN_CONNECTION 0x0001 /** Request was made via a proxy */ #define EVHTTP_PROXY_REQUEST 0x0002 /** The request object is owned by the user; the user must free it */ #define EVHTTP_USER_OWNED 0x0004 /** The request will be used again upstack; freeing must be deferred */ #define EVHTTP_REQ_DEFER_FREE 0x0008 /** The request should be freed upstack */ #define EVHTTP_REQ_NEEDS_FREE 0x0010 struct evkeyvalq *input_headers; struct evkeyvalq *output_headers; /* address of the remote host and the port connection came from */ char *remote_host; ev_uint16_t remote_port; /* cache of the hostname for evhttp_request_get_host */ char *host_cache; enum evhttp_request_kind kind; enum evhttp_cmd_type type; size_t headers_size; size_t body_size; char *uri; /* uri after HTTP request was parsed */ struct evhttp_uri *uri_elems; /* uri elements */ char major; /* HTTP Major number */ char minor; /* HTTP Minor number */ int response_code; /* HTTP Response code */ char *response_code_line; /* Readable response */ struct evbuffer *input_buffer; /* read data */ ev_int64_t ntoread; unsigned chunked:1, /* a chunked request */ userdone:1; /* the user has sent all data */ struct evbuffer *output_buffer; /* outgoing post or data */ /* Callback */ void (*cb)(struct evhttp_request *, void *); void *cb_arg; /* * Chunked data callback - call for each completed chunk if * specified. If not specified, all the data is delivered via * the regular callback. */ void (*chunk_cb)(struct evhttp_request *, void *); }; #ifdef __cplusplus } #endif #endif /* _EVENT2_HTTP_STRUCT_H_ */