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construct/include/ircd/m/room/head.h

66 lines
2.4 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_ROOM_HEAD_H
namespace ircd::m
{
// [GET] Current Event ID and depth suite (non-locking) (one only)
std::tuple<id::event::buf, int64_t, event::idx> top(std::nothrow_t, const id::room &);
std::tuple<id::event::buf, int64_t, event::idx> top(const id::room &);
// [GET] Current Event ID (non-locking) (one only)
id::event::buf head(std::nothrow_t, const id::room &);
id::event::buf head(const id::room &);
// [GET] Current Event idx (non-locking) (one only)
event::idx head_idx(std::nothrow_t, const id::room &);
event::idx head_idx(const id::room &);
// [GET] Current Event depth (non-locking)
int64_t depth(std::nothrow_t, const id::room &);
int64_t depth(const id::room &);
}
/// Interface to the room head
///
/// This interface helps compute and represent aspects of the room graph,
/// specifically concerning the "head" or the "front" or the "top" of this
/// graph where events are either furthest from the m.room.create genesis,
/// or are yet unreferenced by another event. Usage of this interface is
/// fundamental when composing the references of a new event on the graph.
///
struct ircd::m::room::head
{
using closure = std::function<void (const event::idx &, const event::id &)>;
using closure_bool = std::function<bool (const event::idx &, const event::id &)>;
static size_t reset(const head &);
static size_t rebuild(const head &);
static void modify(const event::id &, const db::op &, const bool &);
static int64_t make_refs(const head &, json::stack::array &, const size_t &, const bool &);
static bool for_each(const head &, const closure_bool &);
public:
m::room room;
bool for_each(const closure_bool &) const;
void for_each(const closure &) const;
bool has(const event::id &) const;
size_t count() const;
int64_t make_refs(json::stack::array &, const size_t &, const bool &) const;
std::pair<json::array, int64_t> make_refs(const mutable_buffer &, const size_t &, const bool &) const;
head(const m::room &room)
:room{room}
{}
};