The acyclic map code interacts badly with netaddr.IPs.
One of the netaddr.IP fields is an *intern.Value,
and we use a few sentinel values.
Those sentinel values make many of the netaddr data structures appear cyclic.
One option would be to replace the cycle-detection code with
a Floyd-Warshall style algorithm. The downside is that this will take
longer to detect cycles, particularly if the cycle is long.
This problem is exacerbated by the fact that the acyclic cycle detection
code shares a single visited map for the entire data structure,
not just the subsection of the data structure localized to the map.
Unfortunately, the extra allocations and work (and code) to use per-map
visited maps make this option not viable.
Instead, continue to special-case netaddr data types.
name old time/op new time/op delta
Hash-8 22.4µs ± 0% 14.0µs ± 0% -37.59% (p=0.008 n=5+5)
HashMapAcyclic-8 23.8µs ± 0% 24.3µs ± 1% +1.75% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
Hash-8 2.49kB ± 0% 2.16kB ± 0% ~ (p=0.079 n=4+5)
HashMapAcyclic-8 2.53kB ± 0% 2.53kB ± 0% ~ (all equal)
name old allocs/op new allocs/op delta
Hash-8 86.0 ± 0% 77.0 ± 0% -10.47% (p=0.008 n=5+5)
HashMapAcyclic-8 202 ± 0% 202 ± 0% ~ (all equal)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Hash and xor each entry instead, then write final xor'ed result.
name old time/op new time/op delta
Hash-4 33.6µs ± 4% 34.6µs ± 3% +3.03% (p=0.013 n=10+9)
name old alloc/op new alloc/op delta
Hash-4 1.86kB ± 0% 1.77kB ± 0% -5.10% (p=0.000 n=10+9)
name old allocs/op new allocs/op delta
Hash-4 51.0 ± 0% 49.0 ± 0% -3.92% (p=0.000 n=10+10)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Typical maps in production are considerably longer.
This helps benchmarks more accurately reflect the costs per key
vs the costs per map in deephash.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
magicsock.Conn.ParseEndpoint requires a peer's public key,
disco key, and legacy ip/ports in order to do its job.
We currently accomplish that by:
* adding the public key in our wireguard-go fork
* encoding the disco key as magic hostname
* using a bespoke comma-separated encoding
It's a bit messy.
Instead, switch to something simpler: use a json-encoded struct
containing exactly the information we need, in the form we use it.
Our wireguard-go fork still adds the public key to the
address when it passes it to ParseEndpoint, but now the code
compensating for that is just a couple of simple, well-commented lines.
Once this commit is in, we can remove that part of the fork
and remove the compensating code.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
Yes, it printed, but that was an implementation detail for hashing.
And coming optimization will make it print even less.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Josh Bleecher Snyder
Brad Fitzpatrick
Josh Bleecher Snyder