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openmw/components/platform/file.stdio.cpp

97 lines
2.7 KiB
C++

#include "file.hpp"
#include <cassert>
#include <errno.h>
#include <stdexcept>
#include <string.h>
#include <string>
#include <components/files/conversion.hpp>
namespace Platform::File
{
static auto getNativeHandle(Handle handle)
{
assert(handle != Handle::Invalid);
return reinterpret_cast<FILE*>(static_cast<intptr_t>(handle));
}
static int getNativeSeekType(SeekType seek)
{
if (seek == SeekType::Begin)
return SEEK_SET;
if (seek == SeekType::Current)
return SEEK_CUR;
if (seek == SeekType::End)
return SEEK_END;
return -1;
}
Handle open(const std::filesystem::path& filename)
{
FILE* handle = fopen(filename.c_str(), "rb");
if (handle == nullptr)
{
throw std::system_error(errno, std::generic_category(),
std::string("Failed to open '") + Files::pathToUnicodeString(filename) + "' for reading");
}
return static_cast<Handle>(reinterpret_cast<intptr_t>(handle));
}
void close(Handle handle)
{
auto nativeHandle = getNativeHandle(handle);
fclose(nativeHandle);
}
void seek(Handle handle, size_t position, SeekType type /*= SeekType::Begin*/)
{
const auto nativeHandle = getNativeHandle(handle);
const auto nativeSeekType = getNativeSeekType(type);
if (fseek(nativeHandle, position, nativeSeekType) != 0)
{
throw std::system_error(errno, std::generic_category(), std::string("An fseek() call failed"));
}
}
size_t size(Handle handle)
{
auto nativeHandle = getNativeHandle(handle);
const auto oldPos = tell(handle);
seek(handle, 0, SeekType::End);
const auto fileSize = tell(handle);
seek(handle, oldPos, SeekType::Begin);
return static_cast<size_t>(fileSize);
}
size_t tell(Handle handle)
{
auto nativeHandle = getNativeHandle(handle);
long position = ftell(nativeHandle);
if (position == -1)
{
throw std::system_error(errno, std::generic_category(), std::string("An ftell() call failed"));
}
return static_cast<size_t>(position);
}
size_t read(Handle handle, void* data, size_t size)
{
auto nativeHandle = getNativeHandle(handle);
int amount = fread(data, 1, size, nativeHandle);
if (amount == 0 && ferror(nativeHandle))
{
throw std::system_error(errno, std::generic_category(),
std::string("An attempt to read ") + std::to_string(size) + " bytes failed");
}
return static_cast<size_t>(amount);
}
}