mirror of
https://github.com/matrix-construct/construct
synced 2024-11-16 15:00:51 +01:00
78 lines
2.2 KiB
C++
78 lines
2.2 KiB
C++
|
// The Construct
|
||
|
|
//
|
||
|
|
// Copyright (C) The Construct Developers, Authors & Contributors
|
||
|
|
// Copyright (C) 2016-2020 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.
|
||
|
|
|
||
|
|
decltype(ircd::m::room::content::prefetch_max)
|
||
|
|
ircd::m::room::content::prefetch_max
|
||
|
|
{
|
||
|
|
32
|
||
|
|
};
|
||
|
|
|
||
|
|
decltype(ircd::m::room::content::prefetch)
|
||
|
|
ircd::m::room::content::prefetch
|
||
|
|
{
|
||
|
|
{ "name", "ircd.m.room.content.prefetch" },
|
||
|
|
{ "default", 16L },
|
||
|
|
};
|
||
|
|
|
||
|
|
bool
|
||
|
|
ircd::m::room::content::for_each(const closure &closure)
|
||
|
|
const
|
||
|
|
{
|
||
|
|
// ring queue buffer
|
||
|
|
using entry = pair<uint64_t, m::event::idx>;
|
||
|
|
entry queue[prefetch_max];
|
||
|
|
|
||
|
|
// ring queue state
|
||
|
|
size_t i{0}; // monotonic
|
||
|
|
size_t pos{0}; // modulated index of the current ring head.
|
||
|
|
const size_t queue_max
|
||
|
|
{
|
||
|
|
std::min(size_t(prefetch), size_t(prefetch_max))
|
||
|
|
};
|
||
|
|
|
||
|
|
bool ret{true};
|
||
|
|
const auto call_user
|
||
|
|
{
|
||
|
|
[&closure, &queue, &pos, &ret](const json::object &content)
|
||
|
|
{
|
||
|
|
ret = closure(content, queue[pos].first, queue[pos].second);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
m::room::events it{room};
|
||
|
|
for(; it && ret; --it, ++i, pos = i % queue_max)
|
||
|
|
{
|
||
|
|
// Entry at the current ring head. A prefetch has been for this entry
|
||
|
|
// during the last iteration and the fetch will be made this iteration.
|
||
|
|
auto &[depth, event_idx]
|
||
|
|
{
|
||
|
|
queue[pos]
|
||
|
|
};
|
||
|
|
|
||
|
|
// Fetch the content for the event at the current queue pos; this will
|
||
|
|
// be a no-op on the first iteration when the entries are all zero.
|
||
|
|
m::get(std::nothrow, event_idx, "content", call_user);
|
||
|
|
|
||
|
|
// After the user consumed the fetched entry, overwrite it with the
|
||
|
|
// next prefetch and continue the iteration.
|
||
|
|
depth = it.depth();
|
||
|
|
event_idx = it.event_idx();
|
||
|
|
m::prefetch(event_idx, "content");
|
||
|
|
}
|
||
|
|
|
||
|
|
// The primary loop completes when there's no more events left to
|
||
|
|
// prefetch, but another loop around the queue needs to be made for
|
||
|
|
// any fetches still in flight.
|
||
|
|
for(size_t j(i); ret && i < j + queue_max; ++i, pos = i % queue_max)
|
||
|
|
m::get(std::nothrow, queue[pos].second, "content", call_user);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|