pfs_std_allocator.h

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#ifndef PFS_STD_ALLOCATOR_H
#define PFS_STD_ALLOCATOR_H
 
#include "my_config.h"
 
#include <memory>
 
#include "my_compiler.h"
#include "my_inttypes.h"
#include "storage/perfschema/pfs_global.h"
 
struct PFS_builtin_memory_class;
 
template <class T>
struct PFS_std_allocator {
 public:
  typedef T value_type;
 
  PFS_std_allocator(PFS_builtin_memory_class *klass) : m_klass(klass) {}
 
  template <class U>
  constexpr PFS_std_allocator(const PFS_std_allocator<U> &u) noexcept
      : m_klass(u.get_class()) {}
 
  [[nodiscard]] T *allocate(std::size_t n) {
    if (n > std::numeric_limits<std::size_t>::max() / sizeof(T))
      throw std::bad_array_new_length();
 
    const size_t size = n * sizeof(T);
    void *mem = pfs_malloc(m_klass, size, MYF(0));
    if (mem == nullptr) {
      throw std::bad_alloc();
    }
    return static_cast<T *>(mem);
  }
 
  void deallocate(T *p, std::size_t n) noexcept {
    const size_t size = n * sizeof(T);
    pfs_free(m_klass, size, p);
  }
 
  PFS_builtin_memory_class *get_class() const { return m_klass; }
 
 private:
  PFS_builtin_memory_class *m_klass;
};
 
template <class T, class U>
bool operator==(const PFS_std_allocator<T> &t, const PFS_std_allocator<U> &u) {
  return (t.m_klass == u.m_klass);
}
 
template <class T, class U>
bool operator!=(const PFS_std_allocator<T> &t, const PFS_std_allocator<U> &u) {
  return (t.m_klass != u.m_klass);
}
 
#endif