Commit Graph

18 Commits

Author SHA1 Message Date
Dan Laine
289c6c3b15
p2p: use slices package for sorting (#27494)
Co-authored-by: Felix Lange <fjl@twurst.com>
2023-06-19 07:48:12 +02:00
ucwong
ae7db289b8
p2p: initialize maps with known size (#27229) 2023-05-10 10:52:26 +02:00
Felix Lange
101587b3f4
p2p/dnsdisc: fix tests with Go 1.20 (#26690) 2023-02-14 15:58:43 +02:00
Felix Lange
9afc6816d2
common/lru: add generic LRU implementation (#26162)
It seems there is no fully typed library implementation of an LRU cache.
So I wrote one. Method names are the same as github.com/hashicorp/golang-lru,
and the new type can be used as a drop-in replacement.

Two reasons to do this:

- It's much easier to understand what a cache is for when the types are right there.
- Performance: the new implementation is slightly faster and performs zero memory
   allocations in Add when the cache is at capacity. Overall, memory usage of the cache
   is much reduced because keys are values are no longer wrapped in interface.
2022-11-14 15:41:56 +01:00
Boqin@MetaSecureLabs
e6d4aedb8c
p2p: add channel buffers to avoid goroutine leaks in tests (#24929) 2022-09-23 10:51:12 +02:00
Felix Lange
b628d72766
build: upgrade to go 1.19 (#25726)
This changes the CI / release builds to use the latest Go version. It also
upgrades golangci-lint to a newer version compatible with Go 1.19.

In Go 1.19, godoc has gained official support for links and lists. The
syntax for code blocks in doc comments has changed and now requires a
leading tab character. gofmt adapts comments to the new syntax
automatically, so there are a lot of comment re-formatting changes in this
PR. We need to apply the new format in order to pass the CI lint stage with
Go 1.19.

With the linter upgrade, I have decided to disable 'gosec' - it produces
too many false-positive warnings. The 'deadcode' and 'varcheck' linters
have also been removed because golangci-lint warns about them being
unmaintained. 'unused' provides similar coverage and we already have it
enabled, so we don't lose much with this change.
2022-09-10 13:25:40 +02:00
Håvard Anda Estensen
138f0d7494
p2p: use errors.Is for error comparison (#24882)
Co-authored-by: Felix Lange <fjl@twurst.com>
2022-06-07 17:27:21 +02:00
Felix Lange
9244d5cd61
all: update license headers and AUTHORS from git history (#24947) 2022-05-24 20:39:40 +02:00
Felix Lange
16bc57438b
p2p/dnsdisc: fix crash when iterator closed before first call to Next (#22906) 2021-05-20 09:24:41 +02:00
Felix Lange
b8040a430e
cmd/utils: use eth DNS tree for snap discovery (#22808)
This removes auto-configuration of the snap.*.ethdisco.net DNS discovery tree.
Since measurements have shown that > 75% of nodes in all.*.ethdisco.net support
snap, we have decided to retire the dedicated index for snap and just use the eth
tree instead.

The dial iterators of eth and snap now use the same DNS tree in the default configuration,
so both iterators should use the same DNS discovery client instance. This ensures that
the record cache and rate limit are shared. Records will not be requested multiple times.

While testing the change, I noticed that duplicate DNS requests do happen even
when the client instance is shared. This is because the two iterators request the tree
root, link tree root, and first levels of the tree in lockstep. To avoid this problem, the
change also adds a singleflight.Group instance in the client. When one iterator
attempts to resolve an entry which is already being resolved, the singleflight object
waits for the existing resolve call to finish and returns the entry to both places.
2021-05-04 11:29:32 +02:00
Felix Lange
ab8fd4d005
p2p/dnsdisc: rate limit resolving before checking cache (#22566)
This makes the rate limit apply regardless of whether the node is
already cached.
2021-03-24 14:37:20 +02:00
Martin Holst Swende
5bc0343ed3
p2p/dnsdisc: fix flaw in dns size calculation (#22533)
This fixes the calculation of the tree branch factor. With the new
formula, we now creat at most 13 children instead of 30, ensuring
the TXT record size will be below 370 bytes.
2021-03-19 13:20:27 +01:00
Felix Lange
d36276d85e
p2p/dnsdisc: fix hot-spin when all trees are empty (#22313)
In the random sync algorithm used by the DNS node iterator, we first pick a random
tree and then perform one sync action on that tree. This happens in a loop until any
node is found. If no trees contain any nodes, the iterator will enter a hot loop spinning
at 100% CPU.

The fix is complicated. The iterator now checks if a meaningful sync action can
be performed on any tree. If there is nothing to do, it waits for the next root record
recheck time to arrive and then tries again.

Fixes #22306
2021-02-19 09:54:46 +01:00
Martin Michlmayr
4f2784b38f
all: fix typos in comments (#21118) 2020-05-25 10:21:28 +02:00
Felix Lange
57d4898e29
p2p/dnsdisc: re-check tree root when leaf resolution fails (#20682)
This adds additional logic to re-resolve the root name of a tree when a
couple of leaf requests have failed. We need this change to avoid
getting into a failure state where leaf requests keep failing for half
an hour when the tree has been updated.
2020-02-17 15:23:25 +01:00
Felix Lange
191364c350 p2p/dnsdisc: add enode.Iterator API (#20437)
* p2p/dnsdisc: add support for enode.Iterator

This changes the dnsdisc.Client API to support the enode.Iterator
interface.

* p2p/dnsdisc: rate-limit DNS requests

* p2p/dnsdisc: preserve linked trees across root updates

This improves the way links are handled when the link root changes.
Previously, sync would simply remove all links from the current tree and
garbage-collect all unreachable trees before syncing the new list of
links.

This behavior isn't great in certain cases: Consider a structure where
trees A, B, and C reference each other and D links to A. If D's link
root changed, the sync code would first remove trees A, B and C, only to
re-sync them later when the link to A was found again.

The fix for this problem is to track the current set of links in each
clientTree and removing old links only AFTER all links are synced.

* p2p/dnsdisc: deflake iterator test

* cmd/devp2p: adapt dnsClient to new p2p/dnsdisc API

* p2p/dnsdisc: tiny comment fix
2019-12-12 11:15:36 +02:00
Felix Lange
7300365956 p2p/dnsdisc: update to latest EIP-1459 spec (#20168)
This updates the DNS TXT record format to the latest
changes in ethereum/EIPs#2313.
2019-10-16 14:35:24 +03:00
Felix Lange
0568e81701
p2p/dnsdisc: add implementation of EIP-1459 (#20094)
This adds an implementation of node discovery via DNS TXT records to the
go-ethereum library. The implementation doesn't match EIP-1459 exactly,
the main difference being that this implementation uses separate merkle
trees for tree links and ENRs. The EIP will be updated to match p2p/dnsdisc.

To maintain DNS trees, cmd/devp2p provides a frontend for the p2p/dnsdisc
library. The new 'dns' subcommands can be used to create, sign and deploy DNS
discovery trees.
2019-09-25 11:38:13 +02:00