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construct/include/ircd/m/event/prev.h

88 lines
2.5 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_M_EVENT_PREV_H
namespace ircd::m
{
bool for_each(const event::prev &, const event::id::closure_bool &);
size_t degree(const event::prev &);
size_t count(const event::prev &);
std::ostream &pretty(std::ostream &, const event::prev &);
std::string pretty(const event::prev &);
std::ostream &pretty_oneline(std::ostream &, const event::prev &);
std::string pretty_oneline(const event::prev &);
}
/// Interface to the previous-references of an event. This interface overlays
/// on the m::event tuple and adds functionality focused specifically on the
/// various reference properties in the event data.
///
/// Instances of this class "overlay" on the event tuple, meaning one just
/// passes an m::event (or a json::object which would be passed to an m::event)
/// to the constructor of this class. This class only has the properties of
/// the event which contain references, and a suite of functions to work with
/// those references.
struct ircd::m::event::prev
:json::tuple
<
json::property<name::prev_events, json::array>
>
{
static constexpr const size_t MAX
{
20
};
template<size_t N> vector_view<event::id> ids(event::id (&)[N]) const;
template<size_t N> vector_view<event::idx> idxs(event::idx (&)[N]) const;
std::tuple<event::id, json::object> prev_events(const size_t &idx) const;
event::id prev_event(const size_t &idx) const;
bool prev_event_exists(const size_t &idx) const;
bool prev_events_has(const event::id &) const;
size_t prev_events_count() const;
size_t prev_events_exist() const;
bool prev_exist() const;
using super_type::tuple;
using super_type::operator=;
};
template<size_t N>
inline ircd::vector_view<ircd::m::event::idx>
ircd::m::event::prev::idxs(event::idx (&out)[N])
const
{
return vector_view<event::idx>
(
out, m::index(out, *this)
);
}
template<size_t N>
inline ircd::vector_view<ircd::m::event::id>
ircd::m::event::prev::ids(event::id (&out)[N])
const
{
size_t i(0);
m::for_each(*this, [&i, &out](const event::id &event_id)
{
out[i++] = event_id;
return i < N;
});
return vector_view<event::id>
(
out, i
);
}