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//===-- runtime/file.h ------------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Raw system I/O wrappers
#include "io-error.h"
#include "memory.h"
#include <cinttypes>
#include <optional>
namespace Fortran::runtime::io {
enum class OpenStatus { Old, New, Scratch, Replace, Unknown };
enum class CloseStatus { Keep, Delete };
enum class Position { AsIs, Rewind, Append };
enum class Action { Read, Write, ReadWrite };
class OpenFile {
using FileOffset = std::int64_t;
const char *path() const { return path_.get(); }
void set_path(OwningPtr<char> &&, std::size_t bytes);
std::size_t pathLength() const { return pathLength_; }
bool mayRead() const { return mayRead_; }
bool mayWrite() const { return mayWrite_; }
bool mayPosition() const { return mayPosition_; }
bool mayAsynchronous() const { return mayAsynchronous_; }
void set_mayAsynchronous(bool yes) { mayAsynchronous_ = yes; }
FileOffset position() const { return position_; }
bool isTerminal() const { return isTerminal_; }
std::optional<FileOffset> knownSize() const { return knownSize_; }
bool IsOpen() const { return fd_ >= 0; }
void Open(OpenStatus, std::optional<Action>, Position, IoErrorHandler &);
void Predefine(int fd);
void Close(CloseStatus, IoErrorHandler &);
// Reads data into memory; returns amount acquired. Synchronous.
// Partial reads (less than minBytes) signify end-of-file. If the
// buffer is larger than minBytes, and extra returned data will be
// preserved for future consumption, set maxBytes larger than minBytes
// to reduce system calls This routine handles EAGAIN/EWOULDBLOCK and EINTR.
std::size_t Read(FileOffset, char *, std::size_t minBytes,
std::size_t maxBytes, IoErrorHandler &);
// Writes data. Synchronous. Partial writes indicate program-handled
// error conditions.
std::size_t Write(FileOffset, const char *, std::size_t, IoErrorHandler &);
// Truncates the file
void Truncate(FileOffset, IoErrorHandler &);
// Asynchronous transfers
int ReadAsynchronously(FileOffset, char *, std::size_t, IoErrorHandler &);
int WriteAsynchronously(
FileOffset, const char *, std::size_t, IoErrorHandler &);
void Wait(int id, IoErrorHandler &);
void WaitAll(IoErrorHandler &);
struct Pending {
int id;
int ioStat{0};
OwningPtr<Pending> next;
void CheckOpen(const Terminator &);
bool Seek(FileOffset, IoErrorHandler &);
bool RawSeek(FileOffset);
bool RawSeekToEnd();
int PendingResult(const Terminator &, int);
int fd_{-1};
OwningPtr<char> path_;
std::size_t pathLength_;
bool mayRead_{false};
bool mayWrite_{false};
bool mayPosition_{false};
bool mayAsynchronous_{false};
FileOffset position_{0};
std::optional<FileOffset> knownSize_;
bool isTerminal_{false};
int nextId_;
OwningPtr<Pending> pending_;
bool IsATerminal(int fd);
bool IsExtant(const char *path);
bool MayRead(const char *path);
bool MayWrite(const char *path);
bool MayReadAndWrite(const char *path);
} // namespace Fortran::runtime::io