Commit Graph

9 Commits

Author SHA1 Message Date
Joe Tsai
8f86d4f8b9 all: use slices.Collect with maps.Keys instead of xmaps.Keys
In Go 1.23, the standard maps.Keys helper was altered relative to xmaps.Keys
to return and iterator, which can be used with slices.Collect.

Also, Go 1.21 added the clear built-in, which replaces xmaps.Clear,
and is semantically more correct with respect to NaNs.

Updates #8632
Updates #12912
Updates #cleanup

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2024-10-11 11:41:09 -07:00
Andrew Dunham
47b3476eb7 util/lru: add Clear method
Updates tailscale/corp#20109

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I751a669251a70f0134dd1540c19b274a97608a93
2024-05-17 20:01:40 -04:00
Brad Fitzpatrick
7c1d6e35a5 all: use Go 1.22 range-over-int
Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-04-16 15:32:38 -07:00
David Anderson
ed50f360db util/lru: update c.head when deleting the most recently used entry
Fixes tailscale/corp#14747

Signed-off-by: David Anderson <danderson@tailscale.com>
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: David Anderson <danderson@tailscale.com>
2023-09-19 12:17:50 -07:00
David Anderson
95082a8dde util/lru, util/limiter: add debug helper to dump state as HTML
For use in tsweb debug handlers, so that we can easily inspect cache
and limiter state when troubleshooting.

Updates tailscale/corp#3601

Signed-off-by: David Anderson <danderson@tailscale.com>
2023-09-08 14:47:03 -07:00
David Anderson
0909e90890 util/lru: replace container/list with a custom ring implementation
pre-generics container/list is quite unpleasant to use, and the pointer
manipulation operations for an LRU are simple enough to implement directly
now that we have generic types.

With this change, the LRU uses a ring (aka circularly linked list) rather
than a simple doubly-linked list as its internals, because the ring makes
list manipulation edge cases more regular: the only remaining edge case is
the transition between 0 and 1 elements, rather than also having to deal
specially with manipulating the first and last members of the list.

While the primary purpose was improved readability of the code, as it
turns out removing the indirection through an interface box also speeds
up the LRU:

       │ before.txt  │              after.txt              │
       │   sec/op    │   sec/op     vs base                │
LRU-32   67.05n ± 2%   59.73n ± 2%  -10.90% (p=0.000 n=20)

       │ before.txt │             after.txt              │
       │    B/op    │    B/op     vs base                │
LRU-32   21.00 ± 0%   10.00 ± 0%  -52.38% (p=0.000 n=20)

       │ before.txt │           after.txt            │
       │ allocs/op  │ allocs/op   vs base            │
LRU-32   0.000 ± 0%   0.000 ± 0%  ~ (p=1.000 n=20) ¹

Updates #cleanup

Signed-off-by: David Anderson <danderson@tailscale.com>
2023-09-07 16:04:39 -07:00
David Anderson
472eb6f6f5 util/lru: add a microbenchmark
The benchmark simulates an LRU being queries with uniformly random
inputs, in a set that's too large for the LRU, which should stress
the eviction codepath.

Signed-off-by: David Anderson <danderson@tailscale.com>
2023-09-07 16:04:39 -07:00
David Anderson
96c2cd2ada util/limiter: add a keyed token bucket rate limiter
Updates tailscale/corp#3601

Signed-off-by: David Anderson <danderson@tailscale.com>
2023-09-06 17:48:17 -07:00
Brad Fitzpatrick
b0a984dc26 util/lru: add a package for a typed LRU cache
Updates tailscale/corp#7355

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2023-06-28 10:16:15 -07:00