mongoose/examples/json-rpc-over-websocket/main.c
2024-01-09 14:51:19 -03:00

85 lines
3.2 KiB
C

// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved
//
// See https://mongoose.ws/tutorials/json-rpc-over-websocket/
#include "mongoose.h"
static const char *s_listen_on = "ws://localhost:8000";
static const char *s_web_root = "web_root";
static struct mg_rpc *s_rpc_head = NULL;
static void rpc_sum(struct mg_rpc_req *r) {
double a = 0.0, b = 0.0;
mg_json_get_num(r->frame, "$.params[0]", &a);
mg_json_get_num(r->frame, "$.params[1]", &b);
mg_rpc_ok(r, "%g", a + b);
}
static void rpc_mul(struct mg_rpc_req *r) {
double a = 0.0, b = 0.0;
mg_json_get_num(r->frame, "$.params[0]", &a);
mg_json_get_num(r->frame, "$.params[1]", &b);
mg_rpc_ok(r, "%g", a * b);
}
// This RESTful server implements the following endpoints:
// /websocket - upgrade to Websocket, and implement websocket echo server
// any other URI serves static files from s_web_root
static void fn(struct mg_connection *c, int ev, void *ev_data) {
if (ev == MG_EV_OPEN) {
// c->is_hexdumping = 1;
} else if (ev == MG_EV_WS_OPEN) {
c->data[0] = 'W'; // Mark this connection as an established WS client
} else if (ev == MG_EV_HTTP_MSG) {
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
if (mg_http_match_uri(hm, "/websocket")) {
// Upgrade to websocket. From now on, a connection is a full-duplex
// Websocket connection, which will receive MG_EV_WS_MSG events.
mg_ws_upgrade(c, hm, NULL);
} else {
// Serve static files
struct mg_http_serve_opts opts = {.root_dir = s_web_root};
mg_http_serve_dir(c, ev_data, &opts);
}
} else if (ev == MG_EV_WS_MSG) {
// Got websocket frame. Received data is wm->data
struct mg_ws_message *wm = (struct mg_ws_message *) ev_data;
struct mg_iobuf io = {0, 0, 0, 512};
struct mg_rpc_req r = {&s_rpc_head, 0, mg_pfn_iobuf, &io, 0, wm->data};
mg_rpc_process(&r);
if (io.buf) mg_ws_send(c, (char *) io.buf, io.len, WEBSOCKET_OP_TEXT);
mg_iobuf_free(&io);
}
}
static void timer_fn(void *arg) {
struct mg_mgr *mgr = (struct mg_mgr *) arg;
// Broadcast message to all connected websocket clients.
for (struct mg_connection *c = mgr->conns; c != NULL; c = c->next) {
if (c->data[0] != 'W') continue;
mg_ws_printf(c, WEBSOCKET_OP_TEXT, "{%m:%m,%m:[%d,%d,%d]}",
MG_ESC("method"), MG_ESC("notification1"), MG_ESC("params"), 1,
2, 3);
}
}
int main(void) {
struct mg_mgr mgr; // Event manager
mg_mgr_init(&mgr); // Init event manager
mg_log_set(MG_LL_DEBUG); // Set log level
mg_timer_add(&mgr, 5000, MG_TIMER_REPEAT, timer_fn, &mgr); // Init timer
// Configure JSON-RPC functions we're going to handle
mg_rpc_add(&s_rpc_head, mg_str("sum"), rpc_sum, NULL);
mg_rpc_add(&s_rpc_head, mg_str("mul"), rpc_mul, NULL);
mg_rpc_add(&s_rpc_head, mg_str("rpc.list"), mg_rpc_list, &s_rpc_head);
printf("Starting WS listener on %s/websocket\n", s_listen_on);
mg_http_listen(&mgr, s_listen_on, fn, NULL); // Create HTTP listener
for (;;) mg_mgr_poll(&mgr, 1000); // Infinite event loop
mg_mgr_free(&mgr); // Deallocate event manager
mg_rpc_del(&s_rpc_head, NULL); // Deallocate RPC handlers
return 0;
}