From de3bec63c63b0c30a5a4e1d9b4a5478984b888e9 Mon Sep 17 00:00:00 2001 From: Jesper Jensen Date: Tue, 22 Jun 2021 22:16:02 +0200 Subject: Move the comment into routing --- src/routing.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'src/routing.c') diff --git a/src/routing.c b/src/routing.c index d4eaa3f..ff7eadc 100644 --- a/src/routing.c +++ b/src/routing.c @@ -6,6 +6,30 @@ #include #include +// The DHT routing table has a keyspace of 0 -- 2^160 split into buckets of 8. +// When a bucket becomes full, we split it in half. As we further expand the +// routing table we only continue to split the buckets on the side we fall on. +// +// Initially, this may sound like a binary tree (because we split it in two), +// but looking at it as a flat array leads to some interesting intuitions. +// Since we only expand one half of the "tree", the total size is bounded by +// the depth of the tree log2(2^160) == 160. +// +// As a flat array we notice the intrinsic properties of the routing table. +// With a bucket size of 8, the routing table contains 160 * 8 == 1280 nodes. +// As the node ids get less similar to our own our grouping of them becomes +// less detailed. While the bucket we are in contains node very close to us, +// the nodes furthest away from us are grouped in buckets with nodes they +// barely resemble. +// +// +----------------------------+ +// | n1 | n2 | n3 | ... | n1280 | +// +----------------------------+ +// More Less +// <--------Similarity--------> +// <----------Detail----------> +// + #define IDBITS 160 #define BUCKETSIZE 8 // The 3 here is log2(BUCKETSIZE), since the final bucket will contain all those combinations -- cgit v1.2.3