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#include "cru/common/io/CFileStream.h"
#include "cru/common/Exception.h"
#include "cru/common/io/OpenFileFlag.h"
#include "cru/common/io/Stream.h"
#include <cstdio>
namespace cru::io {
static bool ModeCanRead(const char* mode) {
for (const char* p = mode; *p != '\0'; p++) {
if (*p == 'r' || *p == '+') {
return true;
}
}
return false;
}
static bool ModeCanWrite(const char* mode) {
for (const char* p = mode; *p != '\0'; p++) {
if (*p == 'w' || *p == 'a' || *p == '+') {
return true;
}
}
return false;
}
CFileStream::CFileStream(const char* path, const char* mode)
: file_(std::fopen(path, mode)),
readable_(ModeCanRead(mode)),
writable_(ModeCanWrite(mode)),
auto_close_(true) {
if (file_ == nullptr) {
throw ErrnoException(u"Cannot open file.");
}
}
CFileStream::CFileStream(std::FILE* file, bool readable, bool writable,
bool auto_close)
: file_(file),
readable_(readable),
writable_(writable),
auto_close_(auto_close) {
if (file_ == nullptr) {
throw Exception(u"File is NULL.");
}
}
namespace {
/**
* Generally the fopen will return a NULL ptr if the file does not exist. Then
* we must throw FileNotExistException. However, there are cases we have to
* check existence explicitly before. The case is OpenFileFlags::Write is
* specified but OpenFileFlags::Create is not, in which fopen usually create a
* new file automatically but we want a FileNotExistException to be thrown.
*/
std::string ConvertOpenFileFlagToCFileFlag(OpenFileFlag flags,
bool* explicit_check_exist) {
*explicit_check_exist = false;
std::string result;
bool need_read = flags & OpenFileFlags::Read;
bool need_write = flags & OpenFileFlags::Write;
if (!need_write) {
// No need to write? The simplest
// Note even OpenFileFlags::Create is set, we still have to check exist.
return "r";
}
// Now we need writing.
bool create = OpenFileFlags::Create;
if (!create) {
*explicit_check_exist = true;
}
bool append = flags & OpenFileFlags::Append;
if (!need_read) {
return "w";
}
}
} // namespace
CFileStream::CFileStream(String path, OpenFileFlag flags) {}
CFileStream::~CFileStream() {
if (auto_close_ && file_ != nullptr) {
std::fclose(file_);
}
}
bool CFileStream::CanSeek() {
CheckClosed();
return true;
}
static int ConvertOriginFlag(Stream::SeekOrigin origin) {
switch (origin) {
case Stream::SeekOrigin::Begin:
return SEEK_SET;
case Stream::SeekOrigin::Current:
return SEEK_CUR;
case Stream::SeekOrigin::End:
return SEEK_END;
default:
throw Exception(u"Unknown seek origin.");
}
}
Index CFileStream::Seek(Index offset, SeekOrigin origin) {
CheckClosed();
if (std::fseek(file_, offset, ConvertOriginFlag(origin))) {
throw ErrnoException(u"Seek failed.");
}
return Tell();
}
Index CFileStream::Tell() {
CheckClosed();
long position = std::ftell(file_);
if (position == -1) {
throw ErrnoException(u"Tell failed.");
}
return position;
}
void CFileStream::Rewind() {
CheckClosed();
std::rewind(file_);
}
bool CFileStream::CanRead() {
CheckClosed();
return readable_;
}
Index CFileStream::Read(std::byte* buffer, Index offset, Index size) {
CheckClosed();
auto count = std::fread(buffer + offset, 1, size, file_);
return count;
}
bool CFileStream::CanWrite() {
CheckClosed();
return writable_;
}
Index CFileStream::Write(const std::byte* buffer, Index offset, Index size) {
CheckClosed();
auto count = std::fwrite(buffer + offset, 1, size, file_);
return count;
}
void CFileStream::Flush() {
CheckClosed();
std::fflush(file_);
}
void CFileStream::Close() {
if (file_ != nullptr) {
std::fclose(file_);
file_ = nullptr;
}
}
void CFileStream::CheckClosed() {
if (file_ == nullptr) {
throw StreamAlreadyClosedException(u"File is closed.");
}
}
} // namespace cru::io
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