include/library/integer-pool.hpp

   1 #ifndef _library__integer_pool__hpp__included__
   2 #define _library__integer_pool__hpp__included__
   3
   4 #include <cstdint>
   5 #include <vector>
   6
   7 class integer_pool
   8 {
   9 public:
  10 /**
  11  * Create a new pool
  12  */
  13         integer_pool() throw();
  14 /**
  15  * Destroy a pool.
  16  */
  17         ~integer_pool() throw();
  18 /**
  19  * Draw a number from the pool.
  20  *
  21  * Returns: The number drawn.
  22  * Throws std::bad_alloc: Not enough memory.
  23  */
  24         uint64_t operator()() throw(std::bad_alloc);
  25 /**
  26  * Return a number into the pool.
  27  *
  28  * Parameter num: The number to return.
  29  */
  30         void operator()(uint64_t num) throw();
  31 /**
  32  * Temporarily hold an integer.
  33  */
  34         class holder
  35         {
  36         public:
  37 /**
  38  * Allocate an integer.
  39  */
  40                 holder(integer_pool& _pool)
  41                         : pool(_pool)
  42                 {
  43                         i = pool();
  44                         own = true;
  45                 }
  46 /**
  47  * Release an integer.
  48  */
  49                 ~holder()
  50                 {
  51                         if(own) pool(i);
  52                 }
  53 /**
  54  * Grab the integer without transferring ownership.
  55  *
  56  * Returns: The integer.
  57  */
  58                 uint64_t operator()()
  59                 {
  60                         return i;
  61                 }
  62 /**
  63  * Transfer the ownership.
  64  *
  65  * Returns: The integer.
  66  */
  67                 uint64_t commit()
  68                 {
  69                         own = false;
  70                         return i;
  71                 }
  72         private:
  73                 holder(const holder&);
  74                 holder& operator=(const holder&);
  75                 integer_pool& pool;
  76                 bool own;
  77                 uint64_t i;
  78         };
  79 private:
  80         std::vector<uint8_t> _bits;
  81         uint8_t _bits2;
  82         uint8_t* bits;
  83         bool invalid;
  84 };
  85
  86 #endif