util/fastuuid: delete unused package

Its sole user was deleted in 02cafbe1ca.

And it has no public users: https://pkg.go.dev/tailscale.com/util/fastuuid?tab=importedby

And nothing in other Tailsale repos that I can find.

Updates tailscale/corp#24721

Change-Id: I8755770a255a91c6c99f596e6d10c303b3ddf213
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2024-11-20 16:43:32 -08:00 committed by Brad Fitzpatrick
parent 02cafbe1ca
commit 70d1241ca6
2 changed files with 0 additions and 128 deletions

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@ -1,56 +0,0 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Package fastuuid implements a UUID construction using an in process CSPRNG.
package fastuuid
import (
crand "crypto/rand"
"encoding/binary"
"io"
"math/rand/v2"
"sync"
"github.com/google/uuid"
)
// NewUUID returns a new UUID using a pool of generators, good for highly
// concurrent use.
func NewUUID() uuid.UUID {
g := pool.Get().(*generator)
defer pool.Put(g)
return g.newUUID()
}
var pool = sync.Pool{
New: func() any {
return newGenerator()
},
}
type generator struct {
rng rand.ChaCha8
}
func seed() [32]byte {
var r [32]byte
if _, err := io.ReadFull(crand.Reader, r[:]); err != nil {
panic(err)
}
return r
}
func newGenerator() *generator {
return &generator{
rng: *rand.NewChaCha8(seed()),
}
}
func (g *generator) newUUID() uuid.UUID {
var u uuid.UUID
binary.NativeEndian.PutUint64(u[:8], g.rng.Uint64())
binary.NativeEndian.PutUint64(u[8:], g.rng.Uint64())
u[6] = (u[6] & 0x0f) | 0x40 // Version 4
u[8] = (u[8] & 0x3f) | 0x80 // Variant 10
return u
}

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@ -1,72 +0,0 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package fastuuid
import (
"testing"
"github.com/google/uuid"
)
func TestNewUUID(t *testing.T) {
g := pool.Get().(*generator)
defer pool.Put(g)
u := g.newUUID()
if u[6] != (u[6]&0x0f)|0x40 {
t.Errorf("version bits are incorrect")
}
if u[8] != (u[8]&0x3f)|0x80 {
t.Errorf("variant bits are incorrect")
}
}
func BenchmarkBasic(b *testing.B) {
b.Run("NewUUID", func(b *testing.B) {
for range b.N {
NewUUID()
}
})
b.Run("uuid.New-unpooled", func(b *testing.B) {
uuid.DisableRandPool()
for range b.N {
uuid.New()
}
})
b.Run("uuid.New-pooled", func(b *testing.B) {
uuid.EnableRandPool()
for range b.N {
uuid.New()
}
})
}
func BenchmarkParallel(b *testing.B) {
b.Run("NewUUID", func(b *testing.B) {
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
NewUUID()
}
})
})
b.Run("uuid.New-unpooled", func(b *testing.B) {
uuid.DisableRandPool()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
uuid.New()
}
})
})
b.Run("uuid.New-pooled", func(b *testing.B) {
uuid.EnableRandPool()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
uuid.New()
}
})
})
}