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b026ef6bb7
The original CrawlIterator on the discv4 path generated FINDNODE targets
by grinding random pubkeys until their Keccak256 had a specific top-N-bit
prefix matching a per-call rotation index, then sending them. The aim was
to anchor each peer's response to a different /16 region of the global
keyspace.
Empirically (3 x 5-minute runs against mainnet bootnodes):
mode total mean ± std mainnet mean ± std
fast (grind) 5714 ± 117 549 ± 33
fast-random 5306 ± 366 521 ± 124
Means are within 1σ of each other. The grind's only measurable benefit
is reduced run-to-run variance, not higher yield. For long-running
curated crawls (the production use case for cmd/devp2p) the variance
amortises away, so the simplification is worth taking.
Replace the grind with a plain crand.Read on the v4 target, drop the
randomTargetWithPrefix helper, log2Pow2 helper, and the v4-side
prefix-bit math from withDefaults. Drange becomes a v5-only knob and
its doc is updated to say so; the power-of-two requirement is gone.
discv5 is unchanged: it uses native distance rotation, not target
hashes, and was never affected by the grind.
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|---|---|---|
| .. | ||
| discover | ||
| dnsdisc | ||
| enode | ||
| enr | ||
| msgrate | ||
| nat | ||
| netutil | ||
| pipes | ||
| rlpx | ||
| tracker | ||
| config.go | ||
| config_toml.go | ||
| dial.go | ||
| dial_test.go | ||
| message.go | ||
| message_test.go | ||
| metrics.go | ||
| peer.go | ||
| peer_error.go | ||
| peer_test.go | ||
| protocol.go | ||
| server.go | ||
| server_nat.go | ||
| server_nat_test.go | ||
| server_test.go | ||
| transport.go | ||
| transport_test.go | ||
| util.go | ||
| util_test.go | ||