1. 代码
#include "mongoose.h"
// Print HTTP response and signal that we're done
static void send_ev_handler(struct mg_connection* c, int ev, void* ev_data) {
if (ev == MG_EV_TIMER)
{
printf("timeout...\n");
struct http_message* hm = (struct http_message*)c->user_data;
hm->resp_code = 404;
}
else if (ev == MG_EV_POLL) {
//printf("loopping\n");
}
else if (ev == MG_EV_CONNECT) {
// Connected to server. Extract host name from URL
printf("connect successful\n");
}
else if (ev == MG_EV_CLOSE) {
printf("connect closed\n");
struct http_message* hm = (struct http_message*)c->user_data;
hm->resp_code = 200;
}
else if (ev == MG_EV_HTTP_REPLY)
{
struct http_message* hm = (struct http_message*)ev_data;
// 处理HTTP响应
printf("HTTP Response Code: %d\n", hm->resp_code);
printf("HTTP Response Body: %.*s\n", (int)hm->body.len, hm->body.p);
struct http_message* ret = (struct http_message*)c->user_data;
ret->resp_code = hm->resp_code;
}
}
static void send_http_request(const char* url, const char* extra_headers, const char* post_data)
{
struct mg_mgr mgr;
struct mg_connection* nc;
bool done = false;
mg_mgr_init(&mgr, &done);
struct http_message msg;
msg.resp_code = -1;
struct mg_connect_opts opts;
memset(&opts, 0, sizeof(opts));
opts.user_data = &msg;
nc = mg_connect_http_opt(&mgr, send_ev_handler, opts, url, extra_headers,post_data);
mg_set_timer(nc, mg_time() + 5000);
while (msg.resp_code == -1) {
mg_mgr_poll(&mgr, 300);
// 检查定时器是否触发
if (mg_time() >= nc->ev_timer_time) {
printf("connetc timeout\n");
break;
}
}
mg_mgr_free(&mgr);
}
int main()
{
const char json[] = "{\
\"auto_calc_weight\":1,\
\"base_camera\" : 1,\
\"total_cameras\" : 8,\
\"ctrl_model\" : 5,\
\"ipc_ip\" : [\
\"192.168.42.11\",\
\"192.168.42.12\",\
\"192.168.42.13\",\
\"192.168.42.14\",\
\"192.168.42.15\",\
\"192.168.42.16\",\
\"192.168.42.17\",\
\"192.168.42.18\"\
]\
}";
send_http_request("http://192.168.42.11:8880/set_ipc_ctrl_cfg", "Connection: keep-alive\r\nContent-Type: application/json\r\n", json);
return 0;
}
2. 代码说明
2.1 响应判断
发送连接使用mg_connect_http_opt，是因为第三个参数struct mg_connect_opts可以向回调函数传一个void*型的变量，用于发送完请求判断是否收到服务的响应，这里传的时struct http_message msg的地址，并将msg.resp_code = -1，这样在循环等待影响时就可以用做while的循环条件。
while (msg.resp_code == -1) {
mg_mgr_poll(&mgr, 300);
// 检查定时器是否触发
if (mg_time() >= nc->ev_timer_time) {
printf("connetc timeout\n");
break;
}
}
在回调函数中，成功收到服务端的响应后，将ret->resp_code = hm->resp_code赋值为服务端响应码，如果需要获取服务端响应报文，还可以在回调函数中对ret->body进行赋值。
2.2 超时判断
mg_set_timer(nc, mg_time() + 5000);
// 检查定时器是否触发
if (mg_time() >= nc->ev_timer_time) {
printf("connetc timeout\n");
break;
}
上述代码用于超时判断
mg_set_timer设置超时时间
if (mg_time() >= nc->ev_timer_time)用于超时判断
注意：回调函数中的ev == MG_EV_TIMER并不起作用，不知道为何。