This is shorter, skips two allocations, makes the function inlineable
and is safer, since the compiler now check whether
DeviceIDLength == sha256.Size.
The previous implementation was very generic; its tests didn't cover the
actual alphabet for device IDs.
Benchmark results on amd64:
name old time/op new time/op delta
Luhnify-8 1.00µs ± 1% 0.28µs ± 4% -72.38% (p=0.000 n=9+10)
Unluhnify-8 992ns ± 2% 274ns ± 1% -72.39% (p=0.000 n=10+9)
Adds a receive only folder type that does not send changes, and where the user can optionally revert local changes. Also changes some of the icons to make the three folder types distinguishable.
These functions were very naive and slow. We haven't done much about
them because they pretty much don't matter at all for Syncthing
performance. They are however called very often in the discovery server
and these optimizations have a huge effect on the CPU load on the
public discovery servers.
The code isn't exactly obvious, but we have good test coverage on all
these functions.
benchmark old ns/op new ns/op delta
BenchmarkLuhnify-8 12458 1045 -91.61%
BenchmarkUnluhnify-8 12598 1074 -91.47%
BenchmarkChunkify-8 10792 104 -99.04%
benchmark old allocs new allocs delta
BenchmarkLuhnify-8 18 1 -94.44%
BenchmarkUnluhnify-8 18 1 -94.44%
BenchmarkChunkify-8 44 2 -95.45%
benchmark old bytes new bytes delta
BenchmarkLuhnify-8 1278 64 -94.99%
BenchmarkUnluhnify-8 1278 64 -94.99%
BenchmarkChunkify-8 42552 128 -99.70%
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4346
This makes the device ID a real type that can be used in the protobuf
schema. That avoids the juggling back and forth from []byte in a bunch
of places and simplifies the code.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3695
This adds autodetection of the fastest hashing library on startup, thus
handling the performance regression. It also adds an environment
variable to control the selection, STHASHING=standard (Go standard
library version, avoids SIGILL crash when the minio library has bugs on
odd CPUs), STHASHING=minio (to force using the minio version) or unset
for the default autodetection.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3617
