Files
Xenia-Canary/src/xenia/base/mapped_memory.h
2022-07-17 16:34:17 +03:00

94 lines
3.0 KiB
C++

/**
******************************************************************************
* Xenia : Xbox 360 Emulator Research Project *
******************************************************************************
* Copyright 2020 Ben Vanik. All rights reserved. *
* Released under the BSD license - see LICENSE in the root for more details. *
******************************************************************************
*/
#ifndef XENIA_BASE_MAPPED_MEMORY_H_
#define XENIA_BASE_MAPPED_MEMORY_H_
#include <filesystem>
#include <memory>
#include <string_view>
#include "xenia/base/platform.h"
namespace xe {
class MappedMemory {
public:
enum class Mode {
kRead,
kReadWrite,
};
static std::unique_ptr<MappedMemory> Open(const std::filesystem::path& path,
Mode mode, size_t offset = 0,
size_t length = 0);
#if XE_PLATFORM_ANDROID
static std::unique_ptr<MappedMemory> OpenForAndroidContentUri(
const std::string_view uri, Mode mode, size_t offset = 0,
size_t length = 0);
#endif // XE_PLATFORM_ANDROID
MappedMemory() : data_(nullptr), size_(0) {}
MappedMemory(void* data, size_t size) : data_(data), size_(size) {}
MappedMemory(const MappedMemory& mapped_memory) = delete;
MappedMemory& operator=(const MappedMemory& mapped_memory) = delete;
MappedMemory(MappedMemory&& mapped_memory) = delete;
MappedMemory& operator=(MappedMemory&& mapped_memory) = delete;
virtual ~MappedMemory() = default;
// The mapping is still backed by the object the slice was created from, a
// slice is not owning.
std::unique_ptr<MappedMemory> Slice(size_t offset, size_t length) {
return std::unique_ptr<MappedMemory>(
new MappedMemory(data() + offset, length));
}
uint8_t* data() const { return reinterpret_cast<uint8_t*>(data_); }
size_t size() const { return size_; }
// Close, and optionally truncate file to size
virtual void Close(uint64_t truncate_size = 0) {}
virtual void Flush() {}
// Changes the offset inside the file. This will update data() and size()!
virtual bool Remap(size_t offset, size_t length) { return false; }
protected:
void* data_;
size_t size_;
};
class ChunkedMappedMemoryWriter {
public:
virtual ~ChunkedMappedMemoryWriter() = default;
static std::unique_ptr<ChunkedMappedMemoryWriter> Open(
const std::filesystem::path& path, size_t chunk_size,
bool low_address_space = false);
virtual uint8_t* Allocate(size_t length) = 0;
virtual void Flush() = 0;
virtual void FlushNew() = 0;
protected:
ChunkedMappedMemoryWriter(const std::filesystem::path& path,
size_t chunk_size, bool low_address_space)
: path_(path),
chunk_size_(chunk_size),
low_address_space_(low_address_space) {}
std::filesystem::path path_;
size_t chunk_size_;
bool low_address_space_;
};
} // namespace xe
#endif // XENIA_BASE_MAPPED_MEMORY_H_