ladybird/AK/FileStream.h

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/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Stream.h>
#ifndef KERNEL
# include <errno.h>
# include <stdio.h>
namespace AK {
class InputFileStream : public InputStream {
public:
explicit InputFileStream(int fd)
: m_file(fdopen(fd, "r"))
, m_owned(true)
{
if (!m_file)
set_fatal_error();
}
explicit InputFileStream(FILE* fp)
: m_file(fp)
{
if (!m_file)
set_fatal_error();
}
~InputFileStream()
{
if (m_file) {
fflush(m_file);
if (m_owned)
fclose(m_file);
}
}
bool unreliable_eof() const override { return eof(); }
bool eof() const { return feof(m_file); }
size_t read(Bytes bytes) override
{
if (has_any_error())
return 0;
return fread(bytes.data(), sizeof(u8), bytes.size(), m_file);
}
bool read_or_error(Bytes bytes) override
{
if (has_any_error())
return false;
auto size = read(bytes);
if (size < bytes.size()) {
set_recoverable_error();
return false;
}
return true;
}
bool discard_or_error(size_t count) override
{
if (fseek(m_file, count, SEEK_CUR) == 0)
return true;
// TODO: Why not ferror(m_file)?
if (errno != ESPIPE)
return false;
char buf[4];
size_t i = 0;
while (i < count) {
auto size = min(count - i, 4ul);
if (read({ buf, size }) < size) {
// Can't reset here.
return false;
}
i += size;
}
return true;
}
bool seek(size_t offset, int whence = SEEK_SET)
{
return fseek(m_file, offset, whence) == 0;
}
virtual bool handle_any_error() override
{
clearerr(m_file);
return Stream::handle_any_error();
}
void make_unbuffered()
{
setvbuf(m_file, nullptr, _IONBF, 0);
}
private:
FILE* m_file { nullptr };
bool m_owned { false };
};
class OutputFileStream : public OutputStream {
public:
explicit OutputFileStream(int fd)
: m_file(fdopen(fd, "w"))
, m_owned(true)
{
if (!m_file)
set_fatal_error();
}
explicit OutputFileStream(FILE* fp)
: m_file(fp)
{
if (!m_file)
set_fatal_error();
}
~OutputFileStream()
{
if (m_file) {
fflush(m_file);
if (m_owned)
fclose(m_file);
}
}
size_t write(ReadonlyBytes bytes) override
{
auto nwritten = fwrite(bytes.data(), sizeof(u8), bytes.size(), m_file);
m_bytes_written += nwritten;
return nwritten;
}
bool write_or_error(ReadonlyBytes bytes) override
{
auto nwritten = write(bytes);
if (nwritten < bytes.size()) {
set_recoverable_error();
return false;
}
return true;
}
size_t size() const { return m_bytes_written; }
virtual bool handle_any_error() override
{
clearerr(m_file);
return Stream::handle_any_error();
}
void make_unbuffered()
{
setvbuf(m_file, nullptr, _IONBF, 0);
}
private:
FILE* m_file { nullptr };
size_t m_bytes_written { 0 };
bool m_owned { false };
};
}
using AK::InputFileStream;
using AK::OutputFileStream;
#endif