// Copyright (C) 2010, Gabriel Dos Reis.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     - Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//
//     - Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in
//       the documentation and/or other materials provided with the
//       distribution.
//
//     - Neither the name of The Numerical Algorithms Group Ltd. nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <stddef.h>
#include <string>

namespace OpenAxiom {
   // -----------------
   // -- SystemError --
   // -----------------
   // Objects of (type derived from) this type are used to report
   // error orignating from the OpenAxiom core system.
   struct SystemError {
      explicit SystemError(std::string);
      virtual ~SystemError();
      // Return the text of the diagnostic message.
      virtual const std::string& message() const;
   protected:
      const std::string text;
   };

   // Report a file system erro
   void filesystem_error(std::string);
   
   namespace Memory {
      // Datatype for pointers to data.
      typedef void* Pointer;

      // Precision of the host OS storage page unit in byte count
      size_t page_size();

      // Acquire raw memory from the host OS in multiple
      // of storage page nits.
      Pointer os_acquire_raw_memory(size_t);

      // Release raw storage to the hosting OS.  The first operand must
      // be a pointer value previous returned by `os_acquire_raw_memory'.
      // Otherwise, the result is undefined.
      void os_release_raw_memory(Pointer, size_t);

      // -----------------
      // -- FileMapping --
      // -----------------
      struct FileMapping {
         explicit FileMapping(std::string);
         ~FileMapping();
         const char* begin() const { return static_cast<const char*>(start); }
         const char* end() const { return begin() + extent; }
         std::size_t size() const { return extent; }
      protected:
         Pointer start;         // address at the mapped storage
         size_t extent;         // length (in bytes) of the storage
      private:
         FileMapping(const FileMapping&); // not implemented
         FileMapping& operator=(const FileMapping&); // idem
      };
      
   }
}