ladybird/Userland/Libraries/LibCore/File.h
kleines Filmröllchen 10edd38543 LibCore: Keep track of file offset to avoid system call for tell()
This optimization makes the new test run 2x faster.
2023-07-06 21:05:57 +02:00

123 lines
3.5 KiB
C++

/*
* Copyright (c) 2021, sin-ack <sin-ack@protonmail.com>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Badge.h>
#include <AK/BufferedStream.h>
#include <AK/Noncopyable.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/Stream.h>
#include <LibCore/Forward.h>
#include <LibIPC/Forward.h>
namespace Core {
class File final : public SeekableStream {
AK_MAKE_NONCOPYABLE(File);
public:
enum class OpenMode : unsigned {
NotOpen = 0,
Read = 1,
Write = 2,
ReadWrite = 3,
Append = 4,
Truncate = 8,
MustBeNew = 16,
KeepOnExec = 32,
Nonblocking = 64,
DontCreate = 128,
};
enum class ShouldCloseFileDescriptor {
Yes,
No,
};
static ErrorOr<NonnullOwnPtr<File>> open(StringView filename, OpenMode, mode_t = 0644);
static ErrorOr<NonnullOwnPtr<File>> adopt_fd(int fd, OpenMode, ShouldCloseFileDescriptor = ShouldCloseFileDescriptor::Yes);
static ErrorOr<NonnullOwnPtr<File>> standard_input();
static ErrorOr<NonnullOwnPtr<File>> standard_output();
static ErrorOr<NonnullOwnPtr<File>> standard_error();
static ErrorOr<NonnullOwnPtr<File>> open_file_or_standard_stream(StringView filename, OpenMode mode);
File(File&& other) { operator=(move(other)); }
File& operator=(File&& other)
{
if (&other == this)
return *this;
m_mode = exchange(other.m_mode, OpenMode::NotOpen);
m_fd = exchange(other.m_fd, -1);
m_last_read_was_eof = exchange(other.m_last_read_was_eof, false);
return *this;
}
virtual ErrorOr<Bytes> read_some(Bytes) override;
virtual ErrorOr<ByteBuffer> read_until_eof(size_t block_size = 4096) override;
virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
virtual bool is_eof() const override;
virtual bool is_open() const override;
virtual void close() override;
virtual ErrorOr<size_t> seek(i64 offset, SeekMode) override;
virtual ErrorOr<size_t> tell() const override;
virtual ErrorOr<void> truncate(size_t length) override;
// Sets the blocking mode of the file. If blocking mode is disabled, reads
// will fail with EAGAIN when there's no data available to read, and writes
// will fail with EAGAIN when the data cannot be written without blocking
// (due to the send buffer being full, for example).
// See also Socket::set_blocking.
ErrorOr<void> set_blocking(bool enabled);
template<OneOf<::IPC::File, ::Core::MappedFile> VIP>
int leak_fd(Badge<VIP>)
{
m_should_close_file_descriptor = ShouldCloseFileDescriptor::No;
return m_fd;
}
int fd() const
{
return m_fd;
}
virtual ~File() override
{
if (m_should_close_file_descriptor == ShouldCloseFileDescriptor::Yes)
close();
}
static int open_mode_to_options(OpenMode mode);
private:
File(OpenMode mode, ShouldCloseFileDescriptor should_close = ShouldCloseFileDescriptor::Yes)
: m_mode(mode)
, m_should_close_file_descriptor(should_close)
{
}
ErrorOr<void> open_path(StringView filename, mode_t);
OpenMode m_mode { OpenMode::NotOpen };
int m_fd { -1 };
bool m_last_read_was_eof { false };
ShouldCloseFileDescriptor m_should_close_file_descriptor { ShouldCloseFileDescriptor::Yes };
size_t m_file_offset { 0 };
};
AK_ENUM_BITWISE_OPERATORS(File::OpenMode)
using InputBufferedFile = InputBufferedSeekable<File>;
using OutputBufferedFile = OutputBufferedStream<File>;
}