116 lines
4.4 KiB
C
116 lines
4.4 KiB
C
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///\file
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/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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http://www.etlcpp.com
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Copyright(c) 2017 jwellbelove, rlindeman
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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//*****************************************************************************
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#error This header is in development. Do not use.
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//*****************************************************************************
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#ifndef __ETL_ICACHE__
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#define __ETL_ICACHE__
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#include "platform.h"
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#include "delegate.h"
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#include <utility>
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namespace etl
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{
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///**************************************************************************
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/// The base class for all caches.
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///**************************************************************************
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template <typename TKey, typename TValue>
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class icache
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{
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public:
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///************************************************************************
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/// Constructor.
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/// By default, 'write_through' is set to true.
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///************************************************************************
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icache()
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: write_through(true),
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read_store(nullptr),
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write_store(nullptr)
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{
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}
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///************************************************************************
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/// Destructor.
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/// Flushes the cache if necessary.
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///************************************************************************
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virtual ~icache()
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{
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if (!write_through)
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{
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flush();
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}
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}
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///************************************************************************
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/// Sets the function that reads from the store.
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///************************************************************************
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void set_read_function(etl::delegate<key_value_t&(void)> reader_)
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{
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read_store = reader;
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}
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///************************************************************************
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/// Sets the function that writes to the store.
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///************************************************************************
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void set_write_function(etl::delegate<void(const key_value_t&)> writer_)
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{
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write_store = writer;
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}
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///************************************************************************
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/// Sets the 'write through'' flag.
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///************************************************************************
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void set_write_through(bool write_through_)
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{
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write_through = write_through_;
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}
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virtual const T& read(const TKey& key) const = 0; ///< Reads from the cache. May read from the store using read_store.
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virtual void write(const TKey& key, const TValue& value) = 0; ///< Writes to the cache. May write to the store using write_store.
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virtual void flush() = 0; ///< The overridden function should write all changed values to the store.
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protected:
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typedef ETL_OR_STD::pair<TKey, TValue> key_value_t;
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bool write_through; ///< If true, the cache should write changed items back to the store immediately. If false then a flush() or destruct will be required.
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etl::delegate<key_value_t&(void)>* read_store; ///< A function that will read a value from the store into the cache.
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etl::delegate<void(const key_value_t&)>* write_store; ///< A function that will write a value from the cache into the store.
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}
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}
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#endif
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