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node_cache.cpp
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Adrien Béraud authoredAdrien Béraud authored
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node_cache.cpp 4.27 KiB
/*
* Copyright (C) 2014-2019 Savoir-faire Linux Inc.
* Author(s) : Adrien Béraud <adrien.beraud@savoirfairelinux.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "node_cache.h"
namespace dht {
constexpr size_t CLEANUP_MAX_NODES {1024};
constexpr size_t CLEANUP_FREQ {1024};
NodeCache::~NodeCache()
{
cache_4.setExpired();
cache_6.setExpired();
}
Sp<Node>
NodeCache::getNode(const InfoHash& id, sa_family_t family) {
return cache(family).getNode(id);
}
Sp<Node>
NodeCache::getNode(const InfoHash& id, const SockAddr& addr, time_point now, bool confirm, bool client) {
if (not id)
return std::make_shared<Node>(id, addr);
return cache(addr.getFamily()).getNode(id, addr, now, confirm, client);
}
std::vector<Sp<Node>>
NodeCache::getCachedNodes(const InfoHash& id, sa_family_t sa_f, size_t count) const
{
return cache(sa_f).getCachedNodes(id, count);
}
std::vector<Sp<Node>>
NodeCache::NodeMap::getCachedNodes(const InfoHash& id, size_t count) const
{
std::vector<Sp<Node>> nodes;
nodes.reserve(std::min(size(), count));
const_iterator it;
auto dec_it = [this](const_iterator& it) {
auto ret = it;
it = (it == cbegin()) ? cend() : std::prev(it);
return ret;
};
auto it_p = lower_bound(id),
it_n = it_p;
if (not empty())
dec_it(it_p); /* Create 2 separate iterator if we could */
while (nodes.size() < count and (it_n != cend() or it_p != cend())) {
/* If one of the iterator is at the end, then take the other one
If they are both in middle of somewhere comapre both and take
the closest to the id. */
if (it_p == cend()) it = it_n++;
else if (it_n == cend()) it = dec_it(it_p);
else it = id.xorCmp(it_p->first, it_n->first) < 0 ? dec_it(it_p) : it_n++;
if (auto n = it->second.lock())
if ( not n->isExpired() and not n->isClient() )
nodes.emplace_back(std::move(n));
}
return nodes;
}
void
NodeCache::clearBadNodes(sa_family_t family)
{
if (family == 0) {
clearBadNodes(AF_INET);
clearBadNodes(AF_INET6);
} else {
cache(family).clearBadNodes();
}
}
Sp<Node>
NodeCache::NodeMap::getNode(const InfoHash& id)
{
auto wn = find(id);
if (wn == end())
return {};
if (auto n = wn->second.lock())
return n;
erase(wn);
return {};
}
Sp<Node>
NodeCache::NodeMap::getNode(const InfoHash& id, const SockAddr& addr, time_point now, bool confirm, bool client)
{
auto it = emplace(id, std::weak_ptr<Node>{});
auto node = it.first->second.lock();
if (not node) {
node = std::make_shared<Node>(id, addr, client);
it.first->second = node;
if (cleanup_counter++ == CLEANUP_FREQ) {
cleanup();
cleanup_counter = 0;
}
} else if (confirm or node->isOld(now)) {
node->update(addr);
}
return node;
}
void
NodeCache::NodeMap::clearBadNodes() {
for (auto it = cbegin(); it != cend();) {
if (auto n = it->second.lock()) {
n->reset();
++it;
} else {
erase(it++);
}
}
cleanup_counter = 0;
}
void
NodeCache::NodeMap::setExpired() {
for (auto& wn : *this)
if (auto n = wn.second.lock())
n->setExpired();
clear();
cleanup_counter = 0;
}
void
NodeCache::NodeMap::cleanup()
{
auto it = lower_bound(InfoHash::getRandom());
for (size_t n = 0, maxNodes = std::min(size(), CLEANUP_MAX_NODES); n != maxNodes; n++) {
if (it == end())
it = begin();
if (it->second.expired())
erase(it++);
else
++it;
}
}
}