Implement rate limiting on log messages
Addresses issue #317, where logs can get spammed with the same message
nonstop. Created a rate limiting closure on logging functions, which
limits the number of messages being logged per second based on format
string. To keep memory usage as constant as possible, the previous cache
purging at periodic time intervals has been replaced by an LRU that
discards the oldest string when the capacity of the cache is reached.
Signed-off-by: Wendi Yu <wendi.yu@yahoo.ca>
It was one of the top garbage producers on my phone.
It's slated to be deleted and replaced anyway, but this helps in the
meantime.
The go.sum changes look scary, but the new dep only adds 240 bytes to
the binary. The go.sum noise is just cmd/go being aggressive in
including a lot of stuff (which is being fixed in Go 1.15, for what I
understand). And I ran a go mod tidy, which added some too. (I had to
write a custom wrapper around go mod tidy because this mod tidy
normally breaks on tailscale.io/control being missing but referenced
in tests)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>