citra/src/common/memory_ref.h

137 lines
3.3 KiB
C++

// Copyright 2020 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <memory>
#include <vector>
#include <boost/serialization/export.hpp>
#include <boost/serialization/shared_ptr.hpp>
#include <boost/serialization/vector.hpp>
#include "common/assert.h"
#include "common/common_types.h"
/// Abstract host-side memory - for example a static buffer, or local vector
class BackingMem {
public:
virtual ~BackingMem() = default;
virtual u8* GetPtr() = 0;
virtual const u8* GetPtr() const = 0;
virtual std::size_t GetSize() const = 0;
private:
template <class Archive>
void serialize(Archive& ar, const unsigned int) {}
friend class boost::serialization::access;
};
/// Backing memory implemented by a local buffer
class BufferMem : public BackingMem {
public:
BufferMem() = default;
explicit BufferMem(std::size_t size) : data(size) {}
u8* GetPtr() override {
return data.data();
}
const u8* GetPtr() const override {
return data.data();
}
std::size_t GetSize() const override {
return data.size();
}
std::vector<u8>& Vector() {
return data;
}
const std::vector<u8>& Vector() const {
return data;
}
private:
std::vector<u8> data;
template <class Archive>
void serialize(Archive& ar, const unsigned int) {
ar& boost::serialization::base_object<BackingMem>(*this);
ar& data;
}
friend class boost::serialization::access;
};
BOOST_CLASS_EXPORT_KEY(BufferMem);
/// A managed reference to host-side memory. Fast enough to be used everywhere instead of u8*
/// Supports serialization.
class MemoryRef {
public:
MemoryRef() = default;
MemoryRef(std::nullptr_t) {}
MemoryRef(std::shared_ptr<BackingMem> backing_mem_)
: backing_mem(std::move(backing_mem_)), offset(0) {
Init();
}
MemoryRef(std::shared_ptr<BackingMem> backing_mem_, u64 offset_)
: backing_mem(std::move(backing_mem_)), offset(offset_) {
ASSERT(offset < backing_mem->GetSize());
Init();
}
explicit operator bool() const {
return cptr != nullptr;
}
operator u8*() {
return cptr;
}
u8* GetPtr() {
return cptr;
}
operator const u8*() const {
return cptr;
}
const u8* GetPtr() const {
return cptr;
}
std::size_t GetSize() const {
return csize;
}
MemoryRef& operator+=(u32 offset_by) {
ASSERT(offset_by < csize);
offset += offset_by;
Init();
return *this;
}
MemoryRef operator+(u32 offset_by) const {
ASSERT(offset_by < csize);
return MemoryRef(backing_mem, offset + offset_by);
}
private:
std::shared_ptr<BackingMem> backing_mem{};
u64 offset{};
// Cached values for speed
u8* cptr{};
std::size_t csize{};
void Init() {
if (backing_mem) {
cptr = backing_mem->GetPtr() + offset;
csize = static_cast<std::size_t>(backing_mem->GetSize() - offset);
} else {
cptr = nullptr;
csize = 0;
}
}
template <class Archive>
void serialize(Archive& ar, const unsigned int) {
ar& backing_mem;
ar& offset;
Init();
}
friend class boost::serialization::access;
};