mirror of
https://github.com/matrix-construct/construct
synced 2024-11-16 06:51:08 +01:00
129 lines
2.7 KiB
C++
129 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_IOV_H
|
|
|
|
namespace ircd
|
|
{
|
|
template<class T> struct iov;
|
|
}
|
|
|
|
/// iov (iovector) is a forward list composed on a trip up the stack
|
|
/// presenting an iteration of items to a scatter/gather operation like a
|
|
/// socket or JSON generator etc. Add items to the iov by constructing nodes
|
|
/// on your stack.
|
|
///
|
|
template<class T>
|
|
struct ircd::iov
|
|
:std::forward_list<T, typename allocator::node<T>::allocator>
|
|
{
|
|
struct node;
|
|
|
|
using allocator_state = allocator::node<T>;
|
|
using allocator_type = typename allocator_state::allocator;
|
|
using list = std::forward_list<T, allocator_type>;
|
|
using list_node = typename list::iterator::_Node; //TODO: YYY
|
|
|
|
auto size() const
|
|
{
|
|
return std::distance(std::begin(*this), std::end(*this));
|
|
}
|
|
|
|
allocator_state a;
|
|
|
|
iov(): list{a} {}
|
|
};
|
|
|
|
template<class T>
|
|
struct ircd::iov<T>::node
|
|
:iov::list_node
|
|
{
|
|
iov *const i {nullptr};
|
|
|
|
operator const T &() const;
|
|
operator T &();
|
|
|
|
node() = default;
|
|
template<class... args> node(iov *const &, args&&...);
|
|
template<class... args> node(iov &, args&&...);
|
|
node(node &&) = delete;
|
|
node(const node &) = delete;
|
|
node &operator=(node &&) = delete;
|
|
node &operator=(const node &) = delete;
|
|
~node() noexcept;
|
|
};
|
|
|
|
template<class T>
|
|
template<class... args>
|
|
ircd::iov<T>::node::node(iov &iov,
|
|
args&&... a)
|
|
:node
|
|
{
|
|
&iov, std::forward<args>(a)...
|
|
}
|
|
{}
|
|
|
|
template<class T>
|
|
template<class... args>
|
|
ircd::iov<T>::node::node(iov *const &iov,
|
|
args&&... a)
|
|
:i{iov}
|
|
{
|
|
if(!iov)
|
|
return;
|
|
|
|
auto &list
|
|
{
|
|
*static_cast<iov::list *>(iov)
|
|
};
|
|
|
|
auto &list_node
|
|
{
|
|
*static_cast<iov::list_node *>(this)
|
|
};
|
|
|
|
const auto &address
|
|
{
|
|
reinterpret_cast<uint8_t *>(&list_node)
|
|
};
|
|
|
|
list.get_allocator().s->next = reinterpret_cast<T *>(address);
|
|
list.emplace_front(std::forward<args>(a)...);
|
|
}
|
|
|
|
template<class T>
|
|
ircd::iov<T>::node::~node()
|
|
noexcept
|
|
{
|
|
if(i) i->remove_if([this](const T &x)
|
|
{
|
|
return &x == &static_cast<const T &>(*this);
|
|
});
|
|
}
|
|
|
|
template<class T>
|
|
ircd::iov<T>::node::operator
|
|
T &()
|
|
{
|
|
assert(i);
|
|
auto &list_node(static_cast<iov::list_node &>(*this));
|
|
return *list_node._M_valptr(); //TODO: XXX
|
|
}
|
|
|
|
template<class T>
|
|
ircd::iov<T>::node::operator
|
|
const T &()
|
|
const
|
|
{
|
|
assert(i);
|
|
const auto &list_node(static_cast<const iov::list_node &>(*this));
|
|
return *list_node._M_valptr(); //TODO: XXX
|
|
}
|