util.events: Fix comparison of event_name with nil instead of false (fixes #554)

[prosody.git] / util / events.lua

diff --git a/util/events.lua b/util/events.lua
index 40ca39131240c2f9c906021e3fe5a6886361a01d..e2943e4497f75bdda61b50ca11914e623864e6a6 100644 (file)
--- a/util/events.lua
+++ b/util/events.lua
@@ -9,15 +9,23 @@
 
 local pairs = pairs;
 local t_insert = table.insert;
+local t_remove = table.remove;
 local t_sort = table.sort;
 local setmetatable = setmetatable;
 local next = next;
 
-module "events"
+local _ENV = nil;
 
-function new()
+local function new()
+       -- Map event name to ordered list of handlers (lazily built): handlers[event_name] = array_of_handler_functions
        local handlers = {};
+       -- Array of wrapper functions that wrap all events (nil if empty)
+       local global_wrappers;
+       -- Per-event wrappers: wrappers[event_name] = wrapper_function
+       local wrappers = {};
+       -- Event map: event_map[handler_function] = priority_number
        local event_map = {};
+       -- Called on-demand to build handlers entries
        local function _rebuild_index(handlers, event)
                local _handlers = event_map[event];
                if not _handlers or next(_handlers) == nil then return; end
@@ -50,6 +58,9 @@ function new()
                        end
                end
        end;
+       local function get_handlers(event)
+               return handlers[event];
+       end;
        local function add_handlers(handlers)
                for event, handler in pairs(handlers) do
                        add_handler(event, handler);
@@ -60,7 +71,7 @@ function new()
                        remove_handler(event, handler);
                end
        end;
-       local function fire_event(event_name, event_data)
+       local function _fire_event(event_name, event_data)
                local h = handlers[event_name];
                if h then
                        for i=1,#h do
@@ -69,15 +80,82 @@ function new()
                        end
                end
        end;
+       local function fire_event(event_name, event_data)
+               local w = wrappers[event_name] or global_wrappers;
+               if w then
+                       local curr_wrapper = #w;
+                       local function c(event_name, event_data)
+                               curr_wrapper = curr_wrapper - 1;
+                               if curr_wrapper == 0 then
+                                       if global_wrappers == nil or w == global_wrappers then
+                                               return _fire_event(event_name, event_data);
+                                       end
+                                       w, curr_wrapper = global_wrappers, #global_wrappers;
+                                       return w[curr_wrapper](c, event_name, event_data);
+                               else
+                                       return w[curr_wrapper](c, event_name, event_data);
+                               end
+                       end
+                       return w[curr_wrapper](c, event_name, event_data);
+               end
+               return _fire_event(event_name, event_data);
+       end
+       local function add_wrapper(event_name, wrapper)
+               local w;
+               if event_name == false then
+                       w = global_wrappers;
+                       if not w then
+                               w = {};
+                               global_wrappers = w;
+                       end
+               else
+                       w = wrappers[event_name];
+                       if not w then
+                               w = {};
+                               wrappers[event_name] = w;
+                       end
+               end
+               w[#w+1] = wrapper;
+       end
+       local function remove_wrapper(event_name, wrapper)
+               local w;
+               if event_name == false then
+                       w = global_wrappers;
+               else
+                       w = wrappers[event_name];
+               end
+               if not w then return; end
+               for i = #w, 1 do
+                       if w[i] == wrapper then
+                               t_remove(w, i);
+                       end
+               end
+               if #w == 0 then
+                       if event_name == false then
+                               global_wrappers = nil;
+                       else
+                               wrappers[event_name] = nil;
+                       end
+               end
+       end
        return {
                add_handler = add_handler;
                remove_handler = remove_handler;
                add_handlers = add_handlers;
                remove_handlers = remove_handlers;
+               get_handlers = get_handlers;
+               wrappers = {
+                       add_handler = add_wrapper;
+                       remove_handler = remove_wrapper;
+               };
+               add_wrapper = add_wrapper;
+               remove_wrapper = remove_wrapper;
                fire_event = fire_event;
                _handlers = handlers;
                _event_map = event_map;
        };
 end
 
-return _M;
+return {
+       new = new;
+};