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| -rw-r--r-- | include/event.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/include/event.h b/include/event.h new file mode 100644 index 000000000..c9bad7d04 --- /dev/null +++ b/include/event.h @@ -0,0 +1,146 @@ +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2015 Attila Molnar <attilamolnar@hush.com> + * + * This file is part of InspIRCd. InspIRCd is free software: you can + * redistribute it and/or modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + + +#pragma once + +namespace Events +{ + class ModuleEventListener; + class ModuleEventProvider; +} + +/** Provider of one or more cross-module events. + * Modules who wish to provide events for other modules create instances of this class and use + * one of the macros below to fire the event, passing the instance of the event provider class + * to the macro. + * Event providers are identified using a unique identifier string. + */ +class Events::ModuleEventProvider : public ServiceProvider, private dynamic_reference_base::CaptureHook +{ + public: + typedef std::vector<ModuleEventListener*> SubscriberList; + + /** Constructor + * @param mod Module providing the event(s) + * @param eventid Identifier of the event or event group provided, must be unique + */ + ModuleEventProvider(Module* mod, const std::string& eventid) + : ServiceProvider(mod, eventid, SERVICE_DATA) + , prov(mod, eventid) + { + prov.SetCaptureHook(this); + } + + /** Get list of objects subscribed to this event + * @return List of subscribed objects + */ + const SubscriberList& GetSubscribers() const { return prov->subscribers; } + + friend class ModuleEventListener; + + private: + void OnCapture() CXX11_OVERRIDE + { + // If someone else holds the list from now on, clear mine. See below for more info. + if (*prov != this) + subscribers.clear(); + } + + /** Reference to the active provider for this event. In case multiple event providers + * exist for the same event, only one of them contains the list of subscribers. + * To handle the case when we are not the ones with the list, we get it from the provider + * where the dynref points to. + */ + dynamic_reference_nocheck<ModuleEventProvider> prov; + + /** List of objects subscribed to the event(s) provided by us, or empty if multiple providers + * exist with the same name and we are not the ones holding the list. + */ + SubscriberList subscribers; +}; + +/** Base class for abstract classes describing cross-module events. + * Subscribers should NOT inherit directly from this class. + */ +class Events::ModuleEventListener : private dynamic_reference_base::CaptureHook +{ + /** Reference to the provider, can be NULL if none of the provider modules are loaded + */ + dynamic_reference_nocheck<ModuleEventProvider> prov; + + /** Called by the dynref when the event provider becomes available + */ + void OnCapture() CXX11_OVERRIDE + { + prov->subscribers.push_back(this); + } + + public: + /** Constructor + * @param mod Module subscribing + * @param eventid Identifier of the event to subscribe to + */ + ModuleEventListener(Module* mod, const std::string& eventid) + : prov(mod, eventid) + { + prov.SetCaptureHook(this); + // If the dynamic_reference resolved at construction our capture handler wasn't called + if (prov) + ModuleEventListener::OnCapture(); + } + + ~ModuleEventListener() + { + if (prov) + stdalgo::erase(prov->subscribers, this); + } +}; + +/** + * Run the given hook provided by a module + * + * FOREACH_MOD_CUSTOM(accountevprov, AccountEventListener, OnAccountChange, MOD_RESULT, (user, newaccount)) + */ +#define FOREACH_MOD_CUSTOM(prov, listenerclass, func, params) do { \ + const Events::ModuleEventProvider::SubscriberList& _handlers = (prov).GetSubscribers(); \ + for (Events::ModuleEventProvider::SubscriberList::const_iterator _i = _handlers.begin(); _i != _handlers.end(); ++_i) \ + { \ + listenerclass* _t = static_cast<listenerclass*>(*_i); \ + _t->func params ; \ + } \ +} while (0); + +/** + * Run the given hook provided by a module until some module returns MOD_RES_ALLOW or MOD_RES_DENY. + * If no module does that, result is set to MOD_RES_PASSTHRU. + * + * Example: ModResult MOD_RESULT; + * FIRST_MOD_RESULT_CUSTOM(httpevprov, HTTPRequestEventListener, OnHTTPRequest, MOD_RESULT, (request)); + */ +#define FIRST_MOD_RESULT_CUSTOM(prov, listenerclass, func, result, params) do { \ + result = MOD_RES_PASSTHRU; \ + const Events::ModuleEventProvider::SubscriberList& _handlers = (prov).GetSubscribers(); \ + for (Events::ModuleEventProvider::SubscriberList::const_iterator _i = _handlers.begin(); _i != _handlers.end(); ++_i) \ + { \ + listenerclass* _t = static_cast<listenerclass*>(*_i); \ + result = _t->func params ; \ + if (result != MOD_RES_PASSTHRU) \ + break; \ + } \ +} while (0); |