mirror of
https://github.com/matrix-construct/construct
synced 2024-08-26 19:35:17 +02:00
72 lines
2.7 KiB
C++
72 lines
2.7 KiB
C++
// Matrix Construct
|
|
//
|
|
// Copyright (C) Matrix Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies. The
|
|
// full license for this software is available in the LICENSE file.
|
|
|
|
#pragma once
|
|
#define HAVE_IRCD_FS_SYNC_OPTS_H
|
|
|
|
namespace ircd::fs
|
|
{
|
|
struct opts extern const opts_default;
|
|
|
|
int reqprio(int) noexcept __attribute__((const));
|
|
}
|
|
|
|
/// Options common to all operations
|
|
struct ircd::fs::opts
|
|
{
|
|
static const int highest_priority;
|
|
|
|
/// Offset in the file. If this is -1, for writes, it indicates an append
|
|
/// at the end of the file (RWF_APPEND or legacy non-atomic lseek()).
|
|
off_t offset {0};
|
|
|
|
/// Request priority. Lower value takes priority over higher. The lowest
|
|
/// possible priority value is special, on supporting platforms (RWF_HIPRI).
|
|
/// One can either simply set the integer minimum or use the extern value.
|
|
int8_t priority {0};
|
|
|
|
/// Submits the I/O request immediately rather than allowing IRCd to
|
|
/// queue requests for a few iterations of the ircd::ios event loop.
|
|
/// (only relevant to aio).
|
|
bool nodelay {false};
|
|
|
|
/// Setting this to false enables non-blocking behavior. If the operation
|
|
/// would block, EAGAIN is returned. This is only available with RWF_NOWAIT
|
|
/// on newer systems, otherwise this value is ignored and is always true.
|
|
/// This feature makes up for the fact that O_NONBLOCK when opening the
|
|
/// file is ineffective for regular files.
|
|
bool blocking {true};
|
|
|
|
/// Determines whether this operation is conducted via AIO/io_uring. If
|
|
/// not, a direct syscall is made. Using AIO will only block one ircd::ctx
|
|
/// while a direct syscall will block the thread (all contexts). If AIO is
|
|
/// not available or not enabled, or doesn't support this operation,
|
|
/// setting this has no effect. If this system supports io_uring this
|
|
/// option is reused to indicate use of io_uring (as AIO and io_uring are
|
|
/// not used simultaneously).
|
|
bool aio {true};
|
|
|
|
/// The enumerated operation code to identify the type of request being
|
|
/// made at runtime from any abstract list of requests. This is set by
|
|
/// the fs:: interface call and not the user in most cases. The user
|
|
/// should not rely on this value being preserved if, e.g. they set a read
|
|
/// opcode and then pass the opts structure to write().
|
|
enum op op {op::NOOP};
|
|
|
|
opts(const off_t &, const enum op &op);
|
|
opts() = default;
|
|
};
|
|
|
|
inline
|
|
ircd::fs::opts::opts(const off_t &offset,
|
|
const enum op &op)
|
|
:offset{offset}
|
|
,op{op}
|
|
{}
|