使用mongoose来创建嵌入式websocket客户端和http客户端

使用mongoose来创建嵌入式websocket客户端和http客户端

使用mongoose原因

1 嵌入式非常合适
2 在简单需要的场合下，不需要其他文件，只需要两个文件包含
包含mongoose.h 和 mongoose.c 就可以使用了，比较方便，尤其在嵌入式里面，这两个文件就很有用了，不用其他依赖

httpclient

#include "httpclient.h"
#include "mongoose.h"

/* RESTful server host and request URI */


//static const char *s_url =
//"http://www.abc/data/1";

static int s_exit_flag = 0;
static PageCallback gcallback = NULL;
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
	struct http_message *hm = (struct http_message *) ev_data;
	int connect_status;

	switch (ev) {
	case MG_EV_CONNECT:
		connect_status = *(int *)ev_data;
		if (connect_status != 0) {
			printf("Error connecting to server: %s\n", strerror(connect_status));
			s_exit_flag = 1;

		}
		break;
	case MG_EV_HTTP_REPLY:
		//printf("Got reply:\n%.*s\n", (int)hm->body.len, hm->body.p);
		nc->flags |= MG_F_SEND_AND_CLOSE;
		s_exit_flag = 1;
		if (gcallback != NULL)
		{
			gcallback(hm->body.p, (int)hm->body.len);
		}
		break;
	case MG_EV_CLOSE:
		if (s_exit_flag == 0) {
			printf("Server closed connection\n");
			s_exit_flag = 1;
		};
		break;
	default:
		break;
	}
}

int httpclient(const char* url, PageCallback callback)
{
	struct mg_mgr mgr;
	struct mg_connection *nc;
	gcallback = callback;
	mg_mgr_init(&mgr, NULL);
	nc = mg_connect_http(&mgr, ev_handler, url, NULL, NULL);
	mg_set_protocol_http_websocket(nc);

	printf("Starting RESTful client against %s\n", url);
	while (s_exit_flag == 0) {
		mg_mgr_poll(&mgr, 1000);
	}
	mg_mgr_free(&mgr);

	return 0;
}

websocket 客户端

包含mongoose.h 和 mongoose.c 就可以使用了，比较方便，尤其在嵌入式里面，这两个文件就很有用了，不用

#include "mongoose.h"

static int s_done = 0;
static int s_is_connected = 0;

static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
	(void)nc;

	switch (ev) {
	case MG_EV_CONNECT: {
		int status = *((int *)ev_data);
		if (status != 0) {
			printf("-- Connection error: %d\n", status);
		}
		break;
	}
	case MG_EV_WEBSOCKET_HANDSHAKE_DONE: {
		struct http_message *hm = (struct http_message *) ev_data;
		if (hm->resp_code == 101) {
			printf("-- Connected\n");
			s_is_connected = 1;
		}
		else {
			printf("-- Connection failed! HTTP code %d\n", hm->resp_code);
			/* Connection will be closed after this. */
		}
		break;
	}
	case MG_EV_POLL: {
		char msg[500];
		int n = 0;
#ifdef _WIN32 /* Windows console input is special. */
		INPUT_RECORD inp[100];
		HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
		DWORD i, num;
		if (!PeekConsoleInput(h, inp, sizeof(inp) / sizeof(*inp), &num)) break;
		for (i = 0; i < num; i++) {
			if (inp[i].EventType == KEY_EVENT &&
				inp[i].Event.KeyEvent.wVirtualKeyCode == VK_RETURN) {
				break;
			}
		}
		if (i == num) break;
		if (!ReadConsole(h, msg, sizeof(msg), &num, NULL)) break;
		/* Un-unicode. This is totally not the right way to do it. */
		for (i = 0; i < num * 2; i += 2) msg[i / 2] = msg[i];
		n = (int)num;
#else /* For everybody else, we just read() stdin. */
		fd_set read_set, write_set, err_set;
		struct timeval timeout = { 0, 0 };
		FD_ZERO(&read_set);
		FD_ZERO(&write_set);
		FD_ZERO(&err_set);
		FD_SET(0 /* stdin */, &read_set);
		if (select(1, &read_set, &write_set, &err_set, &timeout) == 1) {
			n = read(0, msg, sizeof(msg));
		}
#endif
		if (n <= 0) break;
		while (msg[n - 1] == '\r' || msg[n - 1] == '\n') n--;
		mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, msg, n);
		break;
	}
	case MG_EV_WEBSOCKET_FRAME: {
		struct websocket_message *wm = (struct websocket_message *) ev_data;
		printf("%.*s\n", (int)wm->size, wm->data);
		break;
	}
	case MG_EV_CLOSE: {
		if (s_is_connected) printf("-- Disconnected\n");
		s_done = 1;
		break;
	}
	}
}

int main(int argc, char **argv) {
	struct mg_mgr mgr;
	struct mg_connection *nc;
	const char *chat_server_url = argc > 1 ? argv[1] : "ws://127.0.0.1:8000";

	mg_mgr_init(&mgr, NULL);

	nc = mg_connect_ws(&mgr, ev_handler, chat_server_url, "ws_chat", NULL);
	if (nc == NULL) {
		fprintf(stderr, "Invalid address\n");
		return 1;
	}

	while (!s_done) {
		mg_mgr_poll(&mgr, 100);
	}
	mg_mgr_free(&mgr);

	return 0;
}