server: Add event system

5 files changed, 159 insertions, 0 deletions

diff --git a/broadcast.c b/broadcast.c
index 0517dc3..2970b54 100644
--- a/broadcast.c
+++ b/broadcast.c
@@ -1,8 +1,10 @@
 #include <string.h>
 #include "broadcast.h"
 #include "db.h"
+#include "event.h"
 #include "net.h"
 #include "user_data.h"
+#include "util.h"
 
 
 // Returns whether value was new and therefore inserted into the list.
@@ -72,6 +74,8 @@ void broadcast_online_change(i64 userid){
 	i64 numonline;
 	(void)userdata_online(userid,&numonline);
 
+	event_emit_online(make_timestamp(),name,numonline);
+
 	char *buf;
 	i64 len=asprintf(&buf,"_push online %" PRIi64 " %s\n",numonline,name);
 	free(name);
diff --git a/command.c b/command.c
index b0b9a26..0ae7fa3 100644
--- a/command.c
+++ b/command.c
@@ -7,6 +7,7 @@
 #include "broadcast.h"
 #include "command.h"
 #include "db.h"
+#include "event.h"
 #include "net.h"
 #include "user_data.h"
 #include "util.h"
@@ -160,6 +161,8 @@ static bool cmd_invite(struct conn_data *data,const char *tag,const char **args)
 	char *invitebuf=NULL;
 	i64 invitebuflen=asprintf(&invitebuf,"_push invite %s\n",roomname);
 
+	event_emit_join(make_timestamp(),username,roomname);
+
 	struct db_user_list members=db_list_members(roomid);
 	for(i64 i=0;i<members.count;i++){
 		i64 nfds;
@@ -208,6 +211,8 @@ static bool cmd_send(struct conn_data *data,const char *tag,const char **args){
 	char *username=db_get_username(data->userid);
 	i64 pushbuflen=asprintf(&pushbuf,"_push message %s %s %" PRIi64 " %s\n",
 			roomname,username,timestamp,message);
+
+	event_emit_message(timestamp,message,username,roomname);
 	free(username);
 
 	struct db_user_list members=db_list_members(roomid);
diff --git a/event.c b/event.c
new file mode 100644
index 0000000..40eaff8
--- /dev/null
+++ b/event.c
@@ -0,0 +1,99 @@
+#include <string.h>
+#include "event.h"
+
+
+struct cbs_chain{
+	event_callback_t *cb;
+	struct cbs_chain *prev,*next;
+};
+
+struct cbs_chain *callbacks=NULL,*callbacks_last=NULL;
+
+
+static struct cbs_chain* find_chain_item(event_callback_t *cb){
+	struct cbs_chain *item=callbacks;
+	while(item&&item->cb!=cb)item=item->next;
+	return item;
+}
+
+
+void event_register(event_callback_t *cb){
+	struct cbs_chain *item=find_chain_item(cb);
+	if(item!=NULL){
+		debug("event_register: callback %p already registered!",cb);
+		return;
+	}
+	item=malloc(1,struct cbs_chain);
+	item->cb=cb;
+	item->prev=item->next=NULL;
+	if(callbacks){
+		item->prev=callbacks_last;
+		callbacks_last->next=item;
+		callbacks_last=item;
+	} else {
+		callbacks=callbacks_last=item;
+	}
+}
+
+void event_unregister(event_callback_t *cb){
+	struct cbs_chain *item=find_chain_item(cb);
+	if(item==NULL){
+		debug("event_unregister: callback %p was not registered!",cb);
+		return;
+	}
+	if(item->prev)item->prev->next=item->next;
+	if(item->next)item->next->prev=item->prev;
+	if(callbacks==item)callbacks=item->next;
+	if(callbacks_last==item)callbacks_last=item->prev;
+	free(item);
+}
+
+struct event_item* event_item_alloc(void){
+	struct event_item *event=malloc(1,struct event_item);
+	memset(event,0,sizeof(struct event_item));
+	return event;
+}
+
+void event_item_free(struct event_item *event){
+	if(event->message)free(event->message);
+	if(event->user)free(event->user);
+	if(event->room)free(event->room);
+	free(event);
+}
+
+void event_emit(const struct event_item *event){
+	for(struct cbs_chain *item=callbacks;item!=NULL;item=item->next){
+		item->cb(event);
+	}
+}
+
+void event_emit_message(i64 timestamp,const char *message,const char *user,const char *room){
+	struct event_item *event=event_item_alloc();
+	event->type=EVENT_MESSAGE;
+	event->timestamp=timestamp;
+	event->message=strdup(message);
+	event->user=strdup(user);
+	event->room=strdup(room);
+	event_emit(event);
+	event_item_free(event);
+}
+
+void event_emit_online(i64 timestamp,const char *user,i64 numonline){
+	struct event_item *event=event_item_alloc();
+	event->type=EVENT_ONLINE;
+	event->timestamp=timestamp;
+	event->user=strdup(user);
+	event->num=numonline;
+	event_emit(event);
+	event_item_free(event);
+}
+
+void event_emit_join(i64 timestamp,const char *user,const char *room){
+	struct event_item *event=event_item_alloc();
+	event->type=EVENT_JOIN;
+	event->timestamp=timestamp;
+	event->user=strdup(user);
+	event->room=strdup(room);
+	event_emit(event);
+	event_item_free(event);
+}
diff --git a/event.h b/event.h
new file mode 100644
index 0000000..638cd20
--- /dev/null
+++ b/event.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "global.h"
+
+
+enum event_type{
+	EVENT_MESSAGE,  // message, user, room
+	EVENT_ONLINE,  // user, num
+	EVENT_JOIN,  // user, room
+};
+
+struct event_item{
+	enum event_type type;
+	i64 timestamp;  // always set
+	char *message,*user,*room;
+	i64 num;
+};
+
+typedef void event_callback_t(const struct event_item *event);
+
+
+void event_register(event_callback_t *cb);
+void event_unregister(event_callback_t *cb);
+
+struct event_item* event_item_alloc(void);
+void event_item_free(struct event_item *event);
+
+void event_emit(const struct event_item *event);
+void event_emit_message(i64 timestamp,const char *message,const char *user,const char *room);
+void event_emit_online(i64 timestamp,const char *user,i64 numonline);
+void event_emit_join(i64 timestamp,const char *user,const char *room);
diff --git a/main.c b/main.c
index 5afece8..a754f02 100644
--- a/main.c
+++ b/main.c
@@ -11,6 +11,7 @@
 #include "command.h"
 #include "conn_data.h"
 #include "db.h"
+#include "event.h"
 #include "net.h"
 #include "runloop.h"
 #include "user_data.h"
@@ -145,15 +146,34 @@ void srandomdev(void){
 }
 #endif
 
+__attribute__((unused))
+static void dummy_event_handler(const struct event_item *event){
+	switch(event->type){
+		case EVENT_MESSAGE:
+			debug("event: <%s>@%s: %s",event->user,event->room,event->message);
+			break;
+
+		case EVENT_ONLINE:
+			debug("event: <%s> online=%" PRIi64,event->user,event->num);
+			break;
+
+		case EVENT_JOIN:
+			debug("event: <%s> joins %s",event->user,event->room);
+			break;
+	}
+}
+
 int main(void){
 	srandomdev();
 
 	db_init();
 	int sock=create_server_socket();
 	printf("Listening on port %d\n",PORT);
+	// event_register(dummy_event_handler);
 	runloop_set_timeout(60*1000000,timeout_callback);
 	runloop_add_fd(sock,server_socket_callback,false);
 	runloop_run();
 	printf("Runloop empty, shutting down\n");
+	// event_unregister(dummy_event_handler);
 	db_close();
 }