courgette/region.h

   1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COURGETTE_REGION_H_
   6 #define COURGETTE_REGION_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11
  12 namespace courgette {
  13
  14 // A Region is a descriptor for a region of memory.  It has a start address and
  15 // a length measured in bytes.  The Region object does not own the memory.
  16 //
  17 class Region {
  18  public:
  19   // Default constructor: and empty region.
  20   Region() : start_(NULL), length_(0) {}
  21
  22   // Usual constructor for regions given a |start| address and |length|.
  23   Region(const void* start, size_t length)
  24       : start_(static_cast<const uint8*>(start)),
  25         length_(length) {
  26   }
  27
  28   // String constructor.  Region is owned by the string, so the string should
  29   // have a lifetime greater than the region.
  30   explicit Region(const std::string& string)
  31       : start_(reinterpret_cast<const uint8*>(string.c_str())),
  32         length_(string.length()) {
  33   }
  34
  35   // Copy constructor.
  36   Region(const Region& other) : start_(other.start_), length_(other.length_) {}
  37
  38   // Assignment 'operator' makes |this| region the same as |other|.
  39   Region& assign(const Region& other) {
  40     this->start_ = other.start_;
  41     this->length_ = other.length_;
  42     return *this;
  43   }
  44
  45   // Returns the starting address of the region.
  46   const uint8* start() const { return start_; }
  47
  48   // Returns the length of the region.
  49   size_t length() const { return length_; }
  50
  51   // Returns the address after the last byte of the region.
  52   const uint8* end() const { return start_ + length_; }
  53
  54  private:
  55   const uint8* start_;
  56   size_t length_;
  57
  58   void operator=(const Region&);  // Disallow assignment operator.
  59 };
  60
  61 }  // namespace
  62 #endif  // COURGETTE_REGION_H_