/** * @file llservice.h * @author Phoenix * @date 2004-11-21 * @brief Declaration file for LLService and related classes. * * $LicenseInfo:firstyear=2004&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef LL_LLSERVICE_H #define LL_LLSERVICE_H #include <string> #include <map> #include "lliopipe.h" #include "llchainio.h" /** * @class LLService * @brief This class is the base class for the service classes. * @see LLIOPipe * * The services map a string to a chain factory with a known interface * at the front of the chain. So, to activate a service, call * <code>activate()</code> with the name of the service needed which * will call the associated factory, and return a pointer to the * known interface. * <b>NOTE:</b> If you are implementing a service factory, it is * vitally important that the service pipe is at the front of the * chain. */ class LLService : public LLIOPipe { public: typedef std::shared_ptr<LLChainIOFactory> creator_t; /** * @brief This method is used to register a protocol name with a * a functor that creates the service. * * THOROUGH_DESCRIPTION * @param aParameter A brief description of aParameter. * @return Returns true if a service was successfully registered. */ static bool registerCreator(const std::string& name, creator_t fn); /** * @brief This method connects to a service by name. * * @param name The name of the service to connect to. * @param chain The constructed chain including the service instance. * @param context Context for the activation. * @return An instance of the service for use or NULL on failure. */ static LLIOPipe* activate( const std::string& name, LLPumpIO::chain_t& chain, LLSD context); /** * @brief * * @param name The name of the service to discard. * @return true if service creator was found and discarded. */ static bool discard(const std::string& name); protected: // The creation factory static data. typedef std::map<std::string, creator_t> creators_t; static creators_t sCreatorFunctors; protected: // construction & destruction. since this class is an abstract // base class, it is up to Service implementations to actually // deal with construction and not a public method. How that // construction takes place will be handled by the service // creators. LLService(); virtual ~LLService(); protected: // This frame timer records how long this service has // existed. Useful for derived services to give themselves a // lifetime and expiration. // *NOTE: Phoenix - This functionaity has been moved to the // pump. 2005-12-13 //LLFrameTimer mTimer; // Since services are designed in an 'ask now, respond later' // idiom which probably crosses thread boundaries, almost all // services will need a handle to a response pipe. It will usually // be the job of the service author to derive a useful // implementation of response, and up to the service subscriber to // further derive that class to do something useful when the // response comes in. LLIOPipe::ptr_t mResponse; }; #endif // LL_LLSERVICE_H