src/mem/PoolingAllocator.h

   1 /*
   2 + * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3 + *
   4 + * Squid software is distributed under GPLv2+ license and includes
   5 + * contributions from numerous individuals and organizations.
   6 + * Please see the COPYING and CONTRIBUTORS files for details.
   7 + */
   8
   9 #ifndef SQUID_MEM_POOLINGALLOCATOR_H
  10 #define SQUID_MEM_POOLINGALLOCATOR_H
  11
  12 #include "mem/forward.h"
  13
  14 /// STL Allocator that uses Squid memory pools for memory management
  15 template <class Value>
  16 class PoolingAllocator
  17 {
  18 public:
  19     /* STL Allocator API */
  20     using value_type = Value;
  21     PoolingAllocator() noexcept {}
  22     template <class Other> PoolingAllocator(const PoolingAllocator<Other> &) noexcept {}
  23     value_type *allocate(std::size_t n) { return static_cast<value_type*>(memAllocRigid(n*sizeof(value_type))); }
  24     void deallocate(value_type *vp, std::size_t n) noexcept { memFreeRigid(vp, n*sizeof(value_type)); }
  25
  26     // The following declarations are only necessary for compilers that do not
  27     // fully support C++11 Allocator-related APIs, such as GCC v4.8.
  28     // The corresponding std::allocator declarations are deprecated in C++17.
  29     // TODO: Remove after dropping support for deficient compilers.
  30
  31     using size_type = size_t;
  32     using pointer = Value*;
  33     using const_pointer = const Value*;
  34     using reference = Value&;
  35     using const_reference = const Value&;
  36
  37     template <class OtherValue>
  38     struct rebind {
  39         typedef PoolingAllocator<OtherValue> other;
  40     };
  41
  42     template<class U, class ... Args> void construct(U *p, Args && ... args) { new((void *)p) U(std::forward<Args>(args)...); }
  43     template<typename OtherValue> void destroy(OtherValue *p) { p->~OtherValue(); }
  44 };
  45
  46 template <class L, class R>
  47 inline bool
  48 operator ==(const PoolingAllocator<L>&, const PoolingAllocator<R>&) noexcept
  49 {
  50     return true;
  51 }
  52
  53 template <class L, class R>
  54 inline bool
  55 operator !=(const PoolingAllocator<L> &l, const PoolingAllocator<R> &r) noexcept
  56 {
  57     return !(l == r);
  58 }
  59
  60 #endif /* SQUID_MEM_POOLINGALLOCATOR_H */
  61