jens@0: /*
jens@0:  *  MemoryMap.h
jens@0:  *  Ottoman
jens@0:  *
jens@0:  *  Created by Jens Alfke on 9/17/09.
jens@0:  *  Copyright 2009 Jens Alfke. All rights reserved.
jens@0:  *  BSD-Licensed: See the file "LICENSE.txt" for details.
jens@0:  */
jens@0: 
jens@0: #include "File.h"
jens@0: 
jens@0: namespace Mooseyard {
jens@0:     
jens@0:     /** A flexible memory-map on a file, which can handle multiple discontiguous mapped regions.
jens@0:         Clients usually access this functionality through File, which delegates to it. */
jens@0:     class MemoryMap {
jens@0:     public:
jens@0:         MemoryMap (File* file)                          :_file(file), _nRegions(0), _regions(NULL) { }
jens@0:         ~MemoryMap();
jens@0:         
jens@0:         void mapRegion (off_t position, size_t length);
jens@0:         const void* mappedPosition (off_t position) const;
jens@0:         
jens@0:     private:
jens@0:         UNCOPYABLE(MemoryMap);
jens@0:         class Region;
jens@0:         const void* _at (off_t) const;
jens@0:         
jens@0:         File *_file;
jens@0:         int _nRegions;
jens@0:         Region **_regions;
jens@0:     };
jens@0:     
jens@0:     
jens@0:     class MemoryMap::Region {
jens@0:     public:
jens@0:         Region (File*, off_t position, size_t length);
jens@0:         ~Region();
jens@0:         off_t position() const                  {return _position;}
jens@0:         size_t length() const                   {return _length;}
jens@0:         off_t end() const                       {return _position + _length;}
jens@0:         bool setLength (size_t);          // Returns false if it failed
jens@0:         const void* mappedPosition(off_t);
jens@0:     private:
jens@0:         UNCOPYABLE(Region);
jens@0:         File* const _file;
jens@0:         const off_t _position;
jens@0:         size_t _length;
jens@0:         const uint8_t *_start;
jens@0:     };
jens@0:     
jens@0:     
jens@0: }