5 Commits (a61caea9111b8304414be768a89063721a5ae46c)

Author	SHA1	Message	Date
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>	1 year ago
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>	1 year ago
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>	1 year ago
David Anderson	96c2cd2ada	util/limiter: add a keyed token bucket rate limiter ... Updates tailscale/corp#3601 Signed-off-by: David Anderson <danderson@tailscale.com>	1 year ago
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>	1 year ago