Diff: icache.h

Revision:

0:b47c2a7920c2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/icache.h	Fri Mar 16 16:34:18 2018 +0000
@@ -0,0 +1,117 @@
+///\file
+
+/******************************************************************************
+The MIT License(MIT)
+
+Embedded Template Library.
+https://github.com/ETLCPP/etl
+http://www.etlcpp.com
+
+Copyright(c) 2017 jwellbelove, rlindeman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files(the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+//*****************************************************************************
+#error  This header is in development. Do not use.
+//*****************************************************************************
+
+#ifndef __ETL_ICACHE__
+#define __ETL_ICACHE__
+
+#include "platform.h"
+#include "function.h"
+#include "nullptr.h"
+
+#include <utility>
+
+namespace etl
+{
+  ///**************************************************************************
+  /// The base class for all caches.
+  ///**************************************************************************
+  template <typename TKey, typename TValue>
+  class icache
+  {
+  public:
+
+    ///************************************************************************
+    /// Constructor.
+    /// By default, 'write_through' is set to true.
+    ///************************************************************************
+    icache()
+      : write_through(true),
+        p_read_store(std::nullptr),
+        p_write_store(std::nullptr)
+    {
+    }
+
+    ///************************************************************************
+    /// Destructor.
+    /// Flushes the cache if necessary.
+    ///************************************************************************
+    virtual ~icache()
+    {
+      if (!write_through)
+      {
+        flush();
+      }
+    }
+
+    ///************************************************************************
+    /// Sets the function that reads from the store.
+    ///************************************************************************
+    void set_read_function(etl::ifunction<key_value_t&>* p_read)
+    {
+      p_read_store = p_read;
+    }
+
+    ///************************************************************************
+    /// Sets the function that writes to the store.
+    ///************************************************************************
+    void set_write_function(etl::ifunction<const key_value_t&>* p_write)
+    {
+      p_write_store = p_write;
+    }
+
+    ///************************************************************************
+    /// Sets the 'write through'' flag.
+    ///************************************************************************
+    void set_write_through(bool write_through_)
+    {
+      write_through = write_through_;
+    }
+
+    virtual const T& read(const TKey& key) const = 0;             ///< Reads from the cache. May read from the store using p_read_store.
+    virtual void write(const TKey& key, const TValue& value) = 0; ///< Writes to the cache. May write to the store using p_write_store.
+    virtual void flush() = 0;                                     ///< The overridden function should write all changed values to the store.
+
+  protected:
+
+    typedef std::pair<TKey, TValue> key_value_t;
+
+    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.
+
+    etl::ifunction<key_value_t&>*       p_read_store;  ///< A pointer to the function that will read a value from the store into the cache.
+    etl::ifunction<const key_value_t&>* p_write_store; ///< A pointer to the function that will write a value from the cache into the store.
+  }
+}
+
+#endif
+