Src/Common/Allocators/SimplePooledAlloc.h

   1 // SimplePooledAlloc.h
   2 //
   3 // Copyright (c) 2005 David Ward
   4
   5 #ifndef __SimplePooledAlloc_h__
   6 #define __SimplePooledAlloc_h__
   7
   8 // CSimplePooledAlloc allocates objects T in fixed-size blocks (specified)
   9 // Alloc returns a default-constructed T*
  10 // Memory is only freed on destruction of the allocator
  11
  12 #include <vector>
  13
  14 template<typename T>
  15 class CSimplePooledAlloc {
  16 public:
  17   // Construct with given block size
  18   CSimplePooledAlloc(size_t iBlockSize);
  19
  20   ~CSimplePooledAlloc();
  21
  22   // Return an uninitialized object
  23   T *Alloc();
  24
  25 private:
  26   class CPool {
  27   public:
  28   CPool(size_t iSize):m_iCurrent(0), m_iSize(iSize) {
  29       m_pData = new T[m_iSize];
  30     }
  31     ~CPool() {
  32       delete[]m_pData;
  33     }
  34     T *Alloc() const {
  35       if(m_iCurrent < m_iSize)
  36         return &m_pData[m_iCurrent++];
  37       return NULL;
  38   } private:
  39       mutable size_t m_iCurrent;
  40     size_t m_iSize;
  41     T *m_pData;
  42   };
  43
  44   std::vector < CPool * >m_vPool;
  45
  46   size_t m_iBlockSize;
  47   int m_iCurrent;
  48 };
  49
  50 template < typename T > CSimplePooledAlloc < T >::CSimplePooledAlloc(size_t iSize):m_iBlockSize(iSize), m_iCurrent(0) {
  51   m_vPool.push_back(new CPool(m_iBlockSize));
  52 }
  53
  54 template < typename T > CSimplePooledAlloc < T >::~CSimplePooledAlloc() {
  55   for(size_t i = 0; i < m_vPool.size(); i++)
  56     delete m_vPool[i];
  57 }
  58
  59 template < typename T > T * CSimplePooledAlloc < T >::Alloc() {
  60   T *p = m_vPool[m_iCurrent]->Alloc();
  61   if(p)
  62     return p;
  63   m_vPool.push_back(new CPool(m_iBlockSize));
  64   m_iCurrent++;
  65   return m_vPool.back()->Alloc();
  66 }
  67
  68 #endif // __include__