From b4b39f52dc9f2d5466e0ef3f8932379907331468 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adrien=20B=C3=A9raud?= <adrien.beraud@savoirfairelinux.com>
Date: Fri, 3 Jun 2016 17:20:52 -0400
Subject: [PATCH] dht: new insertNode algorithm
---
src/dht.cpp | 85 ++++++++++++++++++++++++++++++++---------------------
1 file changed, 51 insertions(+), 34 deletions(-)
diff --git a/src/dht.cpp b/src/dht.cpp
index d2cc5376..5fcaf525 100644
--- a/src/dht.cpp
+++ b/src/dht.cpp
@@ -163,6 +163,7 @@ private:
struct Dht::SearchNode {
+ SearchNode() : node() {}
SearchNode(std::shared_ptr<Node> node) : node(node) {}
using AnnounceStatusMap = std::map<Value::Id, std::shared_ptr<Request>>;
@@ -576,31 +577,50 @@ Dht::Search::insertNode(const std::shared_ptr<Node>& snode, time_point now, cons
auto& node = *snode;
const auto& nid = node.id;
- if (node.getFamily() != af) {
- //DHT_LOG.DEBUG("Attempted to insert node in the wrong family.");
- return false;
- }
-
- // Fast track for the case where the node is not relevant for this search
- if (node.isExpired() && nodes.size() >= SEARCH_NODES && id.xorCmp(nid, nodes.back().node->id) > 0)
+ if (node.getFamily() != af)
return false;
bool found = false;
- auto n = std::find_if(nodes.begin(), nodes.end(), [&](const SearchNode& sn) {
- if (sn.node == snode) {
+ auto n = nodes.end();
+ while (n != nodes.begin()) {
+ --n;
+ if (n->node == snode) {
found = true;
- return true;
+ break;
}
- return id.xorCmp(nid, sn.node->id) < 0;
- });
+ if (id.xorCmp(nid, n->node->id) > 0) {
+ ++n;
+ break;
+ }
+ }
bool new_search_node = false;
if (!found) {
- // Be more restricitve if there are too many
- // good or unknown nodes in this search,
- unsigned num_bad_nodes = getNumberOfBadNodes();
- if (nodes.size() - num_bad_nodes >= SEARCH_NODES) {
- if (node.isExpired() or n == nodes.end())
+ // find if and where to trim excessive nodes
+ auto t = nodes.cend();
+ size_t bad = 0; // number of bad nodes (if search is not expired)
+ bool full {false}; // is the search full (has the maximum nodes)
+ if (expired) {
+ // if the search is expired, trim to SEARCH_NODES nodes
+ if (nodes.size() >= SEARCH_NODES) {
+ full = true;
+ t = nodes.begin() + SEARCH_NODES;
+ }
+ } else {
+ // otherwise, trim to SEARCH_NODES nodes, not counting bad nodes
+ bad = getNumberOfBadNodes();
+ full = nodes.size() - bad >= SEARCH_NODES;
+ while (std::distance(nodes.cbegin(), t) - bad > SEARCH_NODES) {
+ --t;
+ if (t->isBad())
+ bad--;
+ }
+ }
+
+ if (full) {
+ if (t != nodes.cend())
+ nodes.resize(std::distance(nodes.cbegin(), t));
+ if (n >= t)
return false;
}
@@ -608,24 +628,22 @@ Dht::Search::insertNode(const std::shared_ptr<Node>& snode, time_point now, cons
if (nodes.empty()) {
step_time = TIME_INVALID;
}
-
n = nodes.insert(n, SearchNode(snode));
node.time = now;
new_search_node = true;
+ if (node.isExpired()) {
+ if (not expired)
+ bad++;
+ } else if (expired) {
+ bad = nodes.size() - 1;
+ expired = false;
+ }
- // trim good nodes
- while (nodes.size() - num_bad_nodes > SEARCH_NODES) {
- if (removeExpiredNode(now))
- num_bad_nodes--;
-
- auto to_remove = std::find_if(nodes.rbegin(), nodes.rend(),
- [](const SearchNode& n) { return not n.isBad(); }
- );
- if (to_remove != nodes.rend()) {
- nodes.erase(std::prev(to_remove.base()));
- } // else, all nodes are expired.
+ while (nodes.size() - bad > SEARCH_NODES) {
+ if (not expired and nodes.back().isBad())
+ bad--;
+ nodes.pop_back();
}
- expired = false;
}
if (not token.empty()) {
n->candidate = false;
@@ -634,6 +652,9 @@ Dht::Search::insertNode(const std::shared_ptr<Node>& snode, time_point now, cons
n->token = token;
expired = false;
}
+ if (new_search_node) {
+ removeExpiredNode(now);
+ }
return new_search_node;
}
@@ -729,10 +750,6 @@ Dht::searchStep(std::shared_ptr<Search> sr)
DHT_LOG.DEBUG("[search %s IPv%c] step (%d requests)", sr->id.toString().c_str(), sr->af == AF_INET ? '4' : '6', sr->currentGetRequests());
sr->step_time = now;
- /*
- * The accurate delay between two refills has not been strongly determined.
- * TODO: Emprical analysis over refill timeout.
- */
if (sr->refill_time + Node::NODE_EXPIRE_TIME < now and sr->nodes.size()-sr->getNumberOfBadNodes() < SEARCH_NODES) {
if (auto added = sr->refill(sr->af == AF_INET ? buckets : buckets6, now)) {
sr->refill_time = now;
--
GitLab