Lime3DS/src/core/file_sys/file_backend.h
2018-02-24 14:46:42 +01:00

86 lines
2.4 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <algorithm>
#include <cstddef>
#include <memory>
#include "common/common_types.h"
#include "core/hle/result.h"
#include "delay_generator.h"
////////////////////////////////////////////////////////////////////////////////////////////////////
// FileSys namespace
namespace FileSys {
class FileBackend : NonCopyable {
public:
FileBackend() {}
virtual ~FileBackend() {}
/**
* Read data from the file
* @param offset Offset in bytes to start reading data from
* @param length Length in bytes of data to read from file
* @param buffer Buffer to read data into
* @return Number of bytes read, or error code
*/
virtual ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const = 0;
/**
* Write data to the file
* @param offset Offset in bytes to start writing data to
* @param length Length in bytes of data to write to file
* @param flush The flush parameters (0 == do not flush)
* @param buffer Buffer to read data from
* @return Number of bytes written, or error code
*/
virtual ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) = 0;
/**
* Get the amount of time a 3ds needs to read those data
* @param length Length in bytes of data read from file
* @return Nanoseconds for the delay
*/
u64 GetReadDelayNs(size_t length) {
if (delay_generator != nullptr) {
return delay_generator->GetReadDelayNs(length);
}
LOG_ERROR(Service_FS, "Delay generator was not initalized. Using default");
delay_generator = std::make_unique<DefaultDelayGenerator>();
return delay_generator->GetReadDelayNs(length);
}
/**
* Get the size of the file in bytes
* @return Size of the file in bytes
*/
virtual u64 GetSize() const = 0;
/**
* Set the size of the file in bytes
* @param size New size of the file
* @return true if successful
*/
virtual bool SetSize(u64 size) const = 0;
/**
* Close the file
* @return true if the file closed correctly
*/
virtual bool Close() const = 0;
/**
* Flushes the file
*/
virtual void Flush() const = 0;
protected:
std::unique_ptr<DelayGenerator> delay_generator;
};
} // namespace FileSys