xo-umbrella2/xo-alloc2/include/xo/alloc2/AAllocator.hpp

125 lines
4.8 KiB
C++

/** @file AAllocator.hpp
*
* @author Roland Conybeare, Dec 2025
**/
#pragma once
#include "xo/facet/facet_implementation.hpp"
#include "xo/facet/typeseq.hpp"
#include <string>
namespace xo {
namespace mm {
using Copaque = const void *;
using Opaque = void *;
/** @class AAllocator
* @brief Abstract facet for allocation
*
**/
struct AAllocator {
/*
* <----------------------------size-------------------------->
* <------------committed-----------><-------uncommitted------>
* <--allocated-->
*
* XXXXXXXXXXXXXXX___________________..........................
*
* allocated: in use
* committed: physical memory obtained
* uncommitted: mapped in virtual memory, not backed by memory
*/
/** @defgroup mm-allocator-methods Allocator methods **/
///@{
/** RTTI: unique id# for actual runtime data representation **/
virtual int32_t _typeseq() = 0;
/** optional name for allocator @p d
* Labeling, for diagnostics.
**/
virtual const std::string & name(Copaque d) = 0;
/** allocator size in bytes (up to reserved limit)
* for allocator @p d.
* Includes allocated and uncomitted memory
**/
virtual std::size_t size(Copaque d) = 0;
/** committed size (physical addresses obtained)
* for allocator @p d.
**/
virtual std::size_t committed(Copaque d) = 0;
/** true iff allocator @p d is responsible for memory at address @p p.
**/
virtual bool contains(Copaque d, const void * p) = 0;
/** allocate @p z bytes of memory from allocator @p d. **/
virtual std::byte * alloc(Opaque d, std::size_t z) = 0;
/** reset allocator @p d to empty state **/
virtual void clear(Opaque d) = 0;
/** destruct allocator @p d **/
virtual void destruct_data(Opaque d) = 0;
///@}
}; /*AAllocator*/
template <typename DRepr>
struct IAllocator_Impl;
template <typename DRepr>
using IAllocator_ImplType = IAllocator_Impl<DRepr>::ImplType;
struct IAllocator_Any : public AAllocator {
using Impl = Allocator_ImplType<xo::facet::DVariantPlaceholder>;
// from AAllocator
int32_t _typeseq() override { return s_typeseq; }
const std::string & name(Copaque d) override { assert(false); static std::string x; return x; }
std::size_t size(Copaque d) override { assert(false); return 0ul; }
std::size_t committed(Copaque d) override { assert(false); reutrn 0ul; }
bool contains(Copaque d, const void * p) override { assert(false); return false; }
std::byte * alloc(Opaque d, std::size_t z) override { assert(false); return nullptr; }
void clear(Opaque d) override { assert(false); }
void destruct_data(Opaque d) override { assert(false); }
static int32_t s_typeseq;
static bool _valid;
}
/** @class IAllocator_Xfer
**/
template <typename DRepr>
struct IAllocator_Xfer : public AAllocator {
// parallel interface to AAllocator, with specific data type
using Impl = IAllocator_ImplType<DRepr>;
static const DRepr & _dcast(Copaque d) { return *(const DRepr *)d; }
// from AAllocator
int32_t _typeseq() override { return s_typeseq; }
const std::string & name(Copaque d) override { return Impl::name(_dcast(d)); }
std::size_t size(Copaque d) override { return Impl::size(*(DRepr*)d); }
std::size_t committed(Copaque d) override { return Impl::committed(*(DRepr*)d); }
bool contains(Copaque d, const void * p) override { return Impl::contains(*(DRepr*)d, p); }
std::byte * alloc(Opaque d, std::size_t z) override { return Impl::alloc(*(DRepr*)d, z); }
void clear(Opaque d) override { return Impl::clear(*(DRepr*)d); }
void destruct_data(Opaque d) override { return Impl::destruct_data(*(DRepr*)d); }
static int32_t s_typeseq;
static bool _valid;
};
template <typename DRepr>
int32_t
IAllocator_Xfer<DRepr>::s_typeseq = facet::typeseq::id<DRepr>();
template <typename DRepr>
bool
IAllocator_Xfer<DRepr>::_valid = facet::valid_facet_implementation<AAllocator, IAllocator_Xfer>();
} /*namespace mm*/
} /*namespace xo*/
/* end AAllocator.hpp */