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// Copyright Epic Games, Inc. All Rights Reserved.
#include "zenstore/basicfile.h"
#include <zencore/except.h>
#include <zencore/filesystem.h>
#include <zencore/fmtutils.h>
#include <zencore/testing.h>
#include <zencore/testutils.h>
#include <fmt/format.h>
#include <gsl/gsl-lite.hpp>
namespace zen {
using namespace fmt::literals;
BasicFile::~BasicFile()
{
Close();
}
void
BasicFile::Open(std::filesystem::path FileName, bool IsCreate)
{
std::error_code Ec;
Open(FileName, IsCreate, Ec);
if (Ec)
{
throw std::system_error(Ec, "failed to open file '{}'"_format(FileName));
}
}
void
BasicFile::Open(std::filesystem::path FileName, bool IsCreate, std::error_code& Ec)
{
const DWORD dwCreationDisposition = IsCreate ? CREATE_ALWAYS : OPEN_EXISTING;
const DWORD dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
const DWORD dwShareMode = FILE_SHARE_READ;
const DWORD dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
HANDLE hTemplateFile = nullptr;
HANDLE FileHandle = CreateFile(FileName.c_str(),
dwDesiredAccess,
dwShareMode,
/* lpSecurityAttributes */ nullptr,
dwCreationDisposition,
dwFlagsAndAttributes,
hTemplateFile);
if (FileHandle == INVALID_HANDLE_VALUE)
{
Ec = zen::MakeErrorCodeFromLastError();
}
m_FileHandle = FileHandle;
}
void
BasicFile::Close()
{
if (m_FileHandle)
{
::CloseHandle(m_FileHandle);
}
}
void
BasicFile::Read(void* Data, uint64_t Size, uint64_t Offset)
{
OVERLAPPED Ovl{};
Ovl.Offset = DWORD(Offset & 0xffff'ffffu);
Ovl.OffsetHigh = DWORD(Offset >> 32);
DWORD dwNumberOfBytesToRead = gsl::narrow<DWORD>(Size);
DWORD dwNumberOfBytesRead = 0;
BOOL Success = ::ReadFile(m_FileHandle, Data, dwNumberOfBytesToRead, &dwNumberOfBytesRead, &Ovl);
if (!Success)
{
ThrowLastError("Failed to read from file '{}'"_format(zen::PathFromHandle(m_FileHandle)));
}
}
IoBuffer
BasicFile::ReadAll()
{
IoBuffer Buffer(FileSize());
Read((void*)Buffer.Data(), Buffer.Size(), 0);
return Buffer;
}
void
BasicFile::StreamFile(std::function<void(const void* Data, uint64_t Size)>&& ChunkFun)
{
StreamByteRange(0, FileSize(), std::move(ChunkFun));
}
void
BasicFile::StreamByteRange(uint64_t FileOffset, uint64_t Size, std::function<void(const void* Data, uint64_t Size)>&& ChunkFun)
{
const uint64_t ChunkSize = 128 * 1024;
IoBuffer ReadBuffer{ChunkSize};
void* BufferPtr = ReadBuffer.MutableData();
uint64_t RemainBytes = Size;
uint64_t CurrentOffset = FileOffset;
while (RemainBytes)
{
const uint64_t ThisChunkBytes = zen::Min(ChunkSize, RemainBytes);
Read(BufferPtr, ThisChunkBytes, CurrentOffset);
ChunkFun(BufferPtr, ThisChunkBytes);
CurrentOffset += ThisChunkBytes;
RemainBytes -= ThisChunkBytes;
}
}
void
BasicFile::Write(const void* Data, uint64_t Size, uint64_t Offset)
{
OVERLAPPED Ovl{};
Ovl.Offset = DWORD(Offset & 0xffff'ffffu);
Ovl.OffsetHigh = DWORD(Offset >> 32);
DWORD dwNumberOfBytesToWrite = gsl::narrow<DWORD>(Size);
DWORD dwNumberOfBytesWritten = 0;
BOOL Success = ::WriteFile(m_FileHandle, Data, dwNumberOfBytesToWrite, &dwNumberOfBytesWritten, &Ovl);
if (!Success)
{
ThrowLastError("Failed to write to file '{}'"_format(zen::PathFromHandle(m_FileHandle)));
}
}
void
BasicFile::Flush()
{
FlushFileBuffers(m_FileHandle);
}
uint64_t
BasicFile::FileSize()
{
ULARGE_INTEGER liFileSize;
liFileSize.LowPart = ::GetFileSize(m_FileHandle, &liFileSize.HighPart);
return uint64_t(liFileSize.QuadPart);
}
#if ZEN_WITH_TESTS
TEST_CASE("BasicFile")
{
ScopedCurrentDirectoryChange _;
BasicFile File1;
CHECK_THROWS(File1.Open("zonk", false));
CHECK_NOTHROW(File1.Open("zonk", true));
CHECK_NOTHROW(File1.Write("abcd", 4, 0));
CHECK(File1.FileSize() == 4);
}
void
basicfile_forcelink()
{
}
#endif
} // namespace zen
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