cethcan: long poll

4 files changed, 121 insertions, 4 deletions

diff --git a/cethcan/Makefile b/cethcan/Makefile
index 633c2f6..ca4a433 100644
--- a/cethcan/Makefile
+++ b/cethcan/Makefile
@@ -4,7 +4,7 @@ love: cethcan
 PKGS="libevent jansson"
 
 cethcan: main.o can.o ether.o light.o http.o
-	gcc -g -o $@ `pkg-config --libs $(PKGS)` $^
+	gcc -g -o $@ `pkg-config --libs $(PKGS)` -lcrypto $^
 
 clean:
 	rm -f *.o *.y.c *.y.h *.l.c cethcan
diff --git a/cethcan/cethcan.h b/cethcan/cethcan.h
index 64d185b..fd821fc 100644
--- a/cethcan/cethcan.h
+++ b/cethcan/cethcan.h
@@ -52,6 +52,7 @@ struct can_message {
 
 enum json_subtype {
 	JSON_NORMAL = 0,
+	JSON_LONGPOLL = 1,
 };
 
 typedef void (*can_handler)(void *arg, struct can_message *msg);
@@ -74,6 +75,8 @@ extern void can_broadcast(struct can_user *origin, struct can_message *msg);
 extern void can_json(json_t *json, enum json_subtype type);
 extern void can_init(void);
 
+extern void json_bump_longpoll(void);
+
 extern int ether_init(json_t *config);
 extern int light_init_conf(json_t *config);
 extern void http_init(void);
diff --git a/cethcan/http.c b/cethcan/http.c
index e5f7ddb..8316abc 100644
--- a/cethcan/http.c
+++ b/cethcan/http.c
@@ -2,6 +2,7 @@
 
 #include <event2/http.h>
 #include <event2/buffer.h>
+#include <openssl/sha.h>
 
 static struct evhttp *evhttp;
 
@@ -16,18 +17,127 @@ static void http_json_basic(struct evhttp_request *req, void *arg)
 	struct evkeyvalq *outhdr = evhttp_request_get_output_headers(req);
 	struct evbuffer *out = evbuffer_new();
 
-	evhttp_add_header(outhdr, "Content-Type", "text/plain; charset=utf-8");
+	evhttp_add_header(outhdr, "Content-Type", "application/json; charset=utf-8");
 
 	json_t *jsout = json_object();
 	can_json(jsout, JSON_NORMAL);
 	json_dump_callback(jsout, evb_json_add, out, JSON_SORT_KEYS | JSON_INDENT(4));
+	json_decref(jsout);
+
 	evhttp_send_reply(req, 200, "OK", out);
 	evbuffer_free(out);
 }
 
+static void http_json_bump(struct evhttp_request *req, void *arg)
+{
+	struct evkeyvalq *outhdr = evhttp_request_get_output_headers(req);
+	struct evbuffer *out = evbuffer_new();
+
+	evhttp_add_header(outhdr, "Content-Type", "text/plain; charset=utf-8");
+	evbuffer_add_printf(out, "OK");
+	evhttp_send_reply(req, 200, "OK", out);
+	evbuffer_free(out);
+
+	json_bump_longpoll();
+}
+
+struct longpoll {
+	struct longpoll *next;
+	struct evhttp_request *req;
+};
+static struct longpoll *longpolls = NULL, **plongpoll = &longpolls;
+static size_t longpoll_count = 0;
+
+static char *longpollbuf = NULL;
+static size_t longpollbuflen = 0;
+static char longpollhash[SHA_DIGEST_LENGTH * 2 + 1] = "";
+
+static void http_json_longpoll(struct evhttp_request *req, void *arg)
+{
+	struct evkeyvalq *outhdr = evhttp_request_get_output_headers(req);
+	struct evbuffer *out;
+	struct longpoll *lp;
+	const char *query;
+	
+	evhttp_add_header(outhdr, "Content-Type", "application/json; charset=utf-8");
+
+	query = evhttp_uri_get_query(evhttp_request_get_evhttp_uri(req));
+	if (query && !strcmp(query, longpollhash)) {
+		lprintf("long poll");
+		evhttp_send_reply_start(req, 200, "OK Long Poll");
+		evhttp_request_own(req);
+
+		lp = calloc(sizeof(*lp), 1);
+		lp->req = req;
+		*plongpoll = lp;
+		plongpoll = &lp->next;
+		longpoll_count++;
+		return;
+	}
+
+	out = evbuffer_new();
+	evbuffer_add(out, longpollbuf, longpollbuflen);
+	evhttp_send_reply(req, 200, "OK Short Poll", out);
+	evbuffer_free(out);
+}
+
+static void longpoll_updatedata(void)
+{
+	json_t *jsout, *jswrap;
+	char *data;
+	unsigned char digest[SHA_DIGEST_LENGTH];
+
+	if (longpollbuf)
+		free(longpollbuf);
+	
+	jsout = json_object();
+	can_json(jsout, JSON_LONGPOLL);
+	data = json_dumps(jsout, JSON_SORT_KEYS | JSON_INDENT(4));
+	SHA1((unsigned char *)data, strlen(data), digest);
+	free(data);
+
+	for (size_t i = 0; i < SHA_DIGEST_LENGTH; i++)
+		sprintf(longpollhash + i * 2, "%02x", digest[i]);
+
+	jswrap = json_object();
+	json_object_set_new(jswrap, "data", jsout);
+	json_object_set_new(jswrap, "ref", json_string(longpollhash));
+	longpollbuf = json_dumps(jswrap, JSON_SORT_KEYS | JSON_INDENT(4));
+	longpollbuflen = strlen(longpollbuf);
+	json_decref(jswrap);
+}
+
+void json_bump_longpoll(void)
+{
+	struct longpoll *lp, *lpnext;
+	struct evbuffer *out;
+
+	longpoll_updatedata();
+
+	out = evbuffer_new();
+	for (lp = longpolls; lp; lp = lpnext) {
+		lpnext = lp->next;
+
+		evbuffer_add(out, longpollbuf, longpollbuflen);
+		evhttp_send_reply_chunk(lp->req, out);
+		/* send_reply_end calls request_free() */
+		evhttp_send_reply_end(lp->req);
+		free(lp);
+	}
+	evbuffer_free(out);
+
+	longpolls = NULL;
+	plongpoll = &longpolls;
+	longpoll_count = 0;
+}
+
 void http_init(void)
 {
 	evhttp = evhttp_new(ev_base);
 	evhttp_set_cb(evhttp, "/", http_json_basic, NULL);
+	evhttp_set_cb(evhttp, "/longpoll", http_json_longpoll, NULL);
+	evhttp_set_cb(evhttp, "/bump", http_json_bump, NULL);
 	evhttp_bind_socket(evhttp, "127.0.0.1", 34999);
+
+	longpoll_updatedata();
 }
diff --git a/cethcan/light.c b/cethcan/light.c
index cb3e94f..cd646d8 100644
--- a/cethcan/light.c
+++ b/cethcan/light.c
@@ -23,11 +23,13 @@ static void light_json_handler(void *arg, json_t *json, enum json_subtype type)
 	json_object_set_new(lobj, "addr", json_integer(l->logical_addr));
 
 	json_object_set_new(lobj, "actual", json_integer(l->actual.val));
-	json_object_set_new(lobj, "actual_ts", json_integer(l->actual.valid));
+	if (type != JSON_LONGPOLL)
+		json_object_set_new(lobj, "actual_ts", json_integer(l->actual.valid));
 	json_object_set_new(lobj, "actual_tschg", json_integer(l->actual.change));
 
 	json_object_set_new(lobj, "set", json_integer(l->set.val));
-	json_object_set_new(lobj, "set_ts", json_integer(l->set.valid));
+	if (type != JSON_LONGPOLL)
+		json_object_set_new(lobj, "set_ts", json_integer(l->set.valid));
 	json_object_set_new(lobj, "set_tschg", json_integer(l->set.change));
 
 	json_object_set_new(json, l->name, lobj);
@@ -59,6 +61,8 @@ static void light_can_handler(void *arg, struct can_message *msg)
 		v->val = dval;
 		time(&v->change);
 		lprintf("%s: set %02x", l->u->name, dval);
+
+		json_bump_longpoll();
 	}
 }