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| author | Josh Bleecher Snyder <josh@tailscale.com> | 2021-05-07 17:01:44 -0700 |
|---|---|---|
| committer | Josh Bleecher Snyder <josharian@gmail.com> | 2021-05-07 18:50:10 -0700 |
| commit | ceb568202b411ffd9a24761b56445181d65fa735 (patch) | |
| tree | 685c815fdc9504b96b08c241c7e4b7b46accd267 | |
| parent | 5190435d6e7914c656c0a9cb93dd98e0ee35727c (diff) | |
| download | tailscale-ceb568202b411ffd9a24761b56445181d65fa735.tar.xz tailscale-ceb568202b411ffd9a24761b56445181d65fa735.zip | |
tailcfg: optimize keyMarshalText
This function accounted for ~1% of all allocs by tailscaled.
It is trivial to improve, so may as well.
name old time/op new time/op delta
KeyMarshalText-8 197ns ± 0% 47ns ± 0% -76.12% (p=0.016 n=4+5)
name old alloc/op new alloc/op delta
KeyMarshalText-8 200B ± 0% 80B ± 0% -60.00% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
KeyMarshalText-8 5.00 ± 0% 1.00 ± 0% -80.00% (p=0.008 n=5+5)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
| -rw-r--r-- | tailcfg/tailcfg.go | 9 | ||||
| -rw-r--r-- | tailcfg/tailcfg_test.go | 10 |
2 files changed, 15 insertions, 4 deletions
diff --git a/tailcfg/tailcfg.go b/tailcfg/tailcfg.go index 483a67867..f1a9e3749 100644 --- a/tailcfg/tailcfg.go +++ b/tailcfg/tailcfg.go @@ -7,7 +7,7 @@ package tailcfg //go:generate go run tailscale.com/cmd/cloner --type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,DNSResolver,RegisterResponse --clonefunc=true --output=tailcfg_clone.go import ( - "bytes" + "encoding/hex" "errors" "fmt" "reflect" @@ -1027,9 +1027,10 @@ func (k MachineKey) HexString() string { return fmt.Sprintf("%x", func (k *MachineKey) UnmarshalText(text []byte) error { return keyUnmarshalText(k[:], "mkey:", text) } func keyMarshalText(prefix string, k [32]byte) []byte { - buf := bytes.NewBuffer(make([]byte, 0, len(prefix)+64)) - fmt.Fprintf(buf, "%s%x", prefix, k[:]) - return buf.Bytes() + buf := make([]byte, len(prefix)+64) + copy(buf, prefix) + hex.Encode(buf[len(prefix):], k[:]) + return buf } func keyUnmarshalText(dst []byte, prefix string, text []byte) error { diff --git a/tailcfg/tailcfg_test.go b/tailcfg/tailcfg_test.go index 410e532e5..7632f3ccb 100644 --- a/tailcfg/tailcfg_test.go +++ b/tailcfg/tailcfg_test.go @@ -518,3 +518,13 @@ func TestEndpointTypeMarshal(t *testing.T) { t.Errorf("got %s; want %s", got, want) } } + +var sinkBytes []byte + +func BenchmarkKeyMarshalText(b *testing.B) { + b.ReportAllocs() + var k [32]byte + for i := 0; i < b.N; i++ { + sinkBytes = keyMarshalText("prefix", k) + } +} |