add node cache, split dhtrunner.h from dht.h

src/node_cache.cpp

@@ -0,0 +1,125 @@
+/*
+ *  Copyright (C) 2014-2016 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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
+ */
+
+#include "node_cache.h"
+
+namespace dht {
+
+std::shared_ptr<Node>
+NodeCache::getNode(const InfoHash& id, sa_family_t family) {
+    return (family == AF_INET ? cache_4 : cache_6).get(id);
+}
+
+std::shared_ptr<Node>
+NodeCache::getNode(const InfoHash& id, const sockaddr* sa, socklen_t sa_len, time_point now, int confirm) {
+    return (sa->sa_family == AF_INET ? cache_4 : cache_6).get(id, sa, sa_len, now, confirm);
+}
+
+void
+NodeCache::clearBadNodes(sa_family_t family)
+{
+    if (family == 0) {
+        clearBadNodes(AF_INET);
+        clearBadNodes(AF_INET6);
+    } else {
+        (family == AF_INET ? cache_4 : cache_6).clearBadNodes();
+    }
+}
+
+std::shared_ptr<Node>
+NodeCache::NodeTree::getLocal(const InfoHash& id)
+{
+    for (auto it = nodes.begin(); it != nodes.end();) {
+        if (auto n = it->lock()) {
+            if (n->id == id) return n;
+            ++it;
+        } else {
+            it = nodes.erase(it);
+        }
+    }
+    return {};
+}
+
+std::shared_ptr<Node>
+NodeCache::NodeTree::get(const InfoHash& id)
+{
+    NodeTree* t = this;
+    for (auto b : id) {
+        if (t->childs.empty())
+            return t->getLocal(id);
+        else
+            t = &t->childs[b];
+    }
+    return {};
+}
+
+std::shared_ptr<Node>
+NodeCache::NodeTree::get(const InfoHash& id, const sockaddr* sa, socklen_t sa_len, time_point now, int confirm)
+{
+    // find the bucket
+    NodeTree* t = this;
+    size_t offset = 0;
+    while (not t->childs.empty() and offset < 4)
+        t = &t->childs[id[offset++]];
+
+    // find node in bucket
+    auto node = t->getLocal(id);
+    if (not node) {
+        node = std::make_shared<Node>(id, sa, sa_len);
+
+        // insert node in bucket
+        if (t->nodes.size() >= 8 && offset < 4) {
+            offset++;
+            t->childs.resize(256);
+            for (auto& w : t->nodes) {
+                if (auto tn = w.lock()) {
+                    t->childs[tn->id[offset]].nodes.emplace_back(std::move(w));
+                }
+            }
+            t->nodes = {};
+            t->childs[id[offset]].nodes.emplace_back(node);
+        } else {
+            t->nodes.emplace_back(node);
+        }
+    } else if (confirm || node->time < now - Node::NODE_EXPIRE_TIME) {
+        node->update(sa, sa_len);
+    }
+    if (confirm)
+        node->received(now, confirm >= 2);
+    return node;
+}
+
+void
+NodeCache::NodeTree::clearBadNodes() {
+    if (childs.empty()) {
+        for (auto it = nodes.begin(); it != nodes.end();) {
+            if (auto n = it->lock()) {
+                n->reset();
+                ++it;
+            } else {
+                it = nodes.erase(it);
+            }
+        }
+    } else {
+        for (auto& c : childs)
+            c.clearBadNodes();
+    }
+}
+
+}