利用 libevent 實現簡單 http client GET、POST
阿新 • • 發佈：2019-01-09
/* Base on code from: http://archives.seul.org/libevent/users/Sep-2010/msg00050.html */ #include "MITLogModule.h" #include <errno.h> #include <stdlib.h> #include <string.h> #include <event2/event.h> #include <event2/buffer.h> #include <event2/http.h> #include <event2/http_struct.h>#include <event2/keyvalq_struct.h> // (default) #define HTTP_CONTENT_TYPE_URL_ENCODED "application/x-www-form-urlencoded" // (use for files: picture, mp3, tar-file etc.) #define HTTP_CONTENT_TYPE_FORM_DATA "multipart/form-data" // (use for plain text) #define HTTP_CONTENT_TYPE_TEXT_PLAIN "text/plain" #define REQUEST_POST_FLAG 2 #define REQUEST_GET_FLAG 3 struct http_request_get { struct evhttp_uri *uri; struct event_base *base; struct evhttp_connection *cn; struct evhttp_request *req; }; struct http_request_post { struct evhttp_uri *uri; struct event_base *base; struct evhttp_connection *cn; struct evhttp_request *req; char *content_type; char *post_data; }; /************************** Ahead Declare ******************************/ void http_requset_post_cb(struct evhttp_request *req, void *arg); void http_requset_get_cb(struct evhttp_request *req, void *arg); int start_url_request(struct http_request_get *http_req, int req_get_flag); /************************** Tools Function ******************************/ static inline void print_request_head_info(struct evkeyvalq *header) { struct evkeyval *first_node = header->tqh_first; while (first_node) { MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"key:%s value:%s", first_node->key, first_node->value); first_node = first_node->next.tqe_next; } } static inline void print_uri_parts_info(const struct evhttp_uri * http_uri) { MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"scheme:%s", evhttp_uri_get_scheme(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"host:%s", evhttp_uri_get_host(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"path:%s", evhttp_uri_get_path(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"port:%d", evhttp_uri_get_port(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"query:%s", evhttp_uri_get_query(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"userinfo:%s", evhttp_uri_get_userinfo(http_uri)); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"fragment:%s", evhttp_uri_get_fragment(http_uri)); } /************************** Request Function ******************************/ void http_requset_post_cb(struct evhttp_request *req, void *arg) { struct http_request_post *http_req_post = (struct http_request_post *)arg; switch(req->response_code) { case HTTP_OK: { struct evbuffer* buf = evhttp_request_get_input_buffer(req); size_t len = evbuffer_get_length(buf); MITLog_DetPuts(MITLOG_LEVEL_COMMON, "print the head info:"); print_request_head_info(req->output_headers); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"len:%zu body size:%zu", len, req->body_size); char *tmp = malloc(len+1); memcpy(tmp, evbuffer_pullup(buf, -1), len); tmp[len] = '\0'; MITLog_DetPuts(MITLOG_LEVEL_COMMON, "print the body:"); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"HTML BODY:%s", tmp); free(tmp); event_base_loopexit(http_req_post->base, 0); break; } case HTTP_MOVEPERM: MITLog_DetPrintf(MITLOG_LEVEL_ERROR, "%s", "the uri moved permanently"); break; case HTTP_MOVETEMP: { const char *new_location = evhttp_find_header(req->input_headers, "Location"); struct evhttp_uri *new_uri = evhttp_uri_parse(new_location); evhttp_uri_free(http_req_post->uri); http_req_post->uri = new_uri; start_url_request((struct http_request_get *)http_req_post, REQUEST_POST_FLAG); return; } default: event_base_loopexit(http_req_post->base, 0); return; } } void http_requset_get_cb(struct evhttp_request *req, void *arg) { struct http_request_get *http_req_get = (struct http_request_get *)arg; switch(req->response_code) { case HTTP_OK: { struct evbuffer* buf = evhttp_request_get_input_buffer(req); size_t len = evbuffer_get_length(buf); MITLog_DetPuts(MITLOG_LEVEL_COMMON, "print the head info:"); print_request_head_info(req->output_headers); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"len:%zu body size:%zu", len, req->body_size); char *tmp = malloc(len+1); memcpy(tmp, evbuffer_pullup(buf, -1), len); tmp[len] = '\0'; MITLog_DetPuts(MITLOG_LEVEL_COMMON, "print the body:"); MITLog_DetPrintf(MITLOG_LEVEL_COMMON,"HTML BODY:%s", tmp); free(tmp); event_base_loopexit(http_req_get->base, 0); break; } case HTTP_MOVEPERM: MITLog_DetPrintf(MITLOG_LEVEL_ERROR, "%s", "the uri moved permanently"); break; case HTTP_MOVETEMP: { const char *new_location = evhttp_find_header(req->input_headers, "Location"); struct evhttp_uri *new_uri = evhttp_uri_parse(new_location); evhttp_uri_free(http_req_get->uri); http_req_get->uri = new_uri; start_url_request(http_req_get, REQUEST_GET_FLAG); return; } default: event_base_loopexit(http_req_get->base, 0); return; } } int start_url_request(struct http_request_get *http_req, int req_get_flag) { if (http_req->cn) evhttp_connection_free(http_req->cn); int port = evhttp_uri_get_port(http_req->uri); http_req->cn = evhttp_connection_base_new(http_req->base, NULL, evhttp_uri_get_host(http_req->uri), (port == -1 ? 80 : port)); /** * Request will be released by evhttp connection * See info of evhttp_make_request() */ if (req_get_flag == REQUEST_POST_FLAG) { http_req->req = evhttp_request_new(http_requset_post_cb, http_req); } else if (req_get_flag == REQUEST_GET_FLAG) { http_req->req = evhttp_request_new(http_requset_get_cb, http_req); } if (req_get_flag == REQUEST_POST_FLAG) { const char *path = evhttp_uri_get_path(http_req->uri); evhttp_make_request(http_req->cn, http_req->req, EVHTTP_REQ_POST, path ? path : "/"); /** Set the post data */ struct http_request_post *http_req_post = (struct http_request_post *)http_req; evbuffer_add(http_req_post->req->output_buffer, http_req_post->post_data, strlen(http_req_post->post_data)); evhttp_add_header(http_req_post->req->output_headers, "Content-Type", http_req_post->content_type); } else if (req_get_flag == REQUEST_GET_FLAG) { const char *query = evhttp_uri_get_query(http_req->uri); const char *path = evhttp_uri_get_path(http_req->uri); size_t len = (query ? strlen(query) : 0) + (path ? strlen(path) : 0) + 1; char *path_query = NULL; if (len > 1) { path_query = calloc(len, sizeof(char)); sprintf(path_query, "%s?%s", path, query); } evhttp_make_request(http_req->cn, http_req->req, EVHTTP_REQ_GET, path_query ? path_query: "/"); } /** Set the header properties */ evhttp_add_header(http_req->req->output_headers, "Host", evhttp_uri_get_host(http_req->uri)); return 0; } /************************** New/Free Function ******************************/ /** * @param get_flag: refer REQUEST_GET_* * */ void *http_request_new(struct event_base* base, const char *url, int req_get_flag, \ const char *content_type, const char* data) { int len = 0; if (req_get_flag == REQUEST_GET_FLAG) { len = sizeof(struct http_request_get); } else if(req_get_flag == REQUEST_POST_FLAG) { len = sizeof(struct http_request_post); } struct http_request_get *http_req_get = calloc(1, len); http_req_get->uri = evhttp_uri_parse(url); print_uri_parts_info(http_req_get->uri); http_req_get->base = base; if (req_get_flag == REQUEST_POST_FLAG) { struct http_request_post *http_req_post = (struct http_request_post *)http_req_get; if (content_type == NULL) { content_type = HTTP_CONTENT_TYPE_URL_ENCODED; } http_req_post->content_type = strdup(content_type); if (data == NULL) { http_req_post->post_data = NULL; } else { http_req_post->post_data = strdup(data); } } return http_req_get; } void http_request_free(struct http_request_get *http_req_get, int req_get_flag) { evhttp_connection_free(http_req_get->cn); evhttp_uri_free(http_req_get->uri); if (req_get_flag == REQUEST_GET_FLAG) { free(http_req_get); } else if(req_get_flag == REQUEST_POST_FLAG) { struct http_request_post *http_req_post = (struct http_request_post*)http_req_get; if (http_req_post->content_type) { free(http_req_post->content_type); } if (http_req_post->post_data) { free(http_req_post->post_data); } free(http_req_post); } http_req_get = NULL; } /************************** Start POST/GET Function ******************************/ /** * @param content_type: refer HTTP_CONTENT_TYPE_* */ void *start_http_requset(struct event_base* base, const char *url, int req_get_flag, \ const char *content_type, const char* data) { struct http_request_get *http_req_get = http_request_new(base, url, req_get_flag, content_type, data); start_url_request(http_req_get, req_get_flag); return http_req_get; } int main(int argc, char *argv[]) { MITLogOpen("LibeventHttpClient"); struct event_base* base = event_base_new(); struct http_request_post *http_req_post = start_http_requset(base, "http://172.16.239.93:8899/base/truck/delete", REQUEST_POST_FLAG, HTTP_CONTENT_TYPE_URL_ENCODED, "name=winlin&code=1234"); struct http_request_get *http_req_get = start_http_requset(base, "http://127.0.0.1?name=winlin", REQUEST_GET_FLAG, NULL, NULL); event_base_dispatch(base); http_request_free((struct http_request_get *)http_req_post, REQUEST_POST_FLAG); http_request_free(http_req_get, REQUEST_GET_FLAG); event_base_free(base); MITLogClose(); return 0; }