/** * @file llchainio.h * @author Phoenix * @date 2005-08-04 * @brief This class declares the interface for constructing io chains. * * $LicenseInfo:firstyear=2005&license=viewerlgpl$ * 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_LLCHAINIO_H #define LL_LLCHAINIO_H #include "llpumpio.h" /** * @class LLDeferredChain * @brief This class allows easy addition of a chain which will sleep * and then process another chain. */ class LLDeferredChain { public: /** * @brief Add a chain to a pump in a finite # of seconds * * @prarm pump The pump to work on. * @prarm in_seconds The number of seconds from now when chain should start. * @prarm chain The chain to add in in_seconds seconds. * @prarm chain_timeout timeout for chain on the pump. * @return Returns true if the operation was queued. */ static bool addToPump( LLPumpIO* pump, F32 in_seconds, const LLPumpIO::chain_t& chain, F32 chain_timeout); }; /** * @class LLChainIOFactory * @brief This class is an abstract base class for building io chains. * * This declares an abstract base class for a chain factory. The * factory is used to connect an input pipe to the first pipe in the * chain, and an output pipe to the last pipe in the chain. This will * allow easy construction for buffer based io like services to for * API centered IO while abstracting the input and output to simple * data passing. * To use this class, you should derive a class which implements the * <code>build</code> method. */ class LLChainIOFactory { public: // Constructor LLChainIOFactory(); // Destructor virtual ~LLChainIOFactory(); /** * @brief Build the chian with in as the first and end as the last * * The caller of the LLChainIOFactory is responsible for managing * the memory of the in pipe. All of the chains generated by the * factory will be ref counted as usual, so the caller will also * need to break the links in the chain. * @param chain The chain which will have new pipes appended * @param context A context for use by this factory if you choose * @retrun Returns true if the call was successful. */ virtual bool build(LLPumpIO::chain_t& chain, LLSD context) const = 0; protected: }; /** * @class LLSimpleIOFactory * @brief Basic implementation for making a factory that returns a * 'chain' of one object */ template<class Pipe> class LLSimpleIOFactory : public LLChainIOFactory { public: virtual bool build(LLPumpIO::chain_t& chain, LLSD context) const { chain.push_back(LLIOPipe::ptr_t(new Pipe)); return true; } }; /** * @class LLCloneIOFactory * @brief Implementation for a facory which copies a particular pipe. */ template<class Pipe> class LLCloneIOFactory : public LLChainIOFactory { public: LLCloneIOFactory(Pipe* original) : mHandle(original), mOriginal(original) {} virtual bool build(LLPumpIO::chain_t& chain, LLSD context) const { chain.push_back(LLIOPipe::ptr_t(new Pipe(*mOriginal))); return true; } protected: LLIOPipe::ptr_t mHandle; Pipe* mOriginal; }; #endif // LL_LLCHAINIO_H