45 lines
875 B
Go
45 lines
875 B
Go
package appinsights
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import (
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"encoding/base64"
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"math/rand"
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"sync/atomic"
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"time"
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"unsafe"
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)
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type concurrentRandom struct {
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channel chan string
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random *rand.Rand
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}
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var randomGenerator *concurrentRandom
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func newConcurrentRandom() *concurrentRandom {
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source := rand.NewSource(time.Now().UnixNano())
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return &concurrentRandom{
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channel: make(chan string, 4),
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random: rand.New(source),
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}
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}
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func (generator *concurrentRandom) run() {
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buf := make([]byte, 8)
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for {
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generator.random.Read(buf)
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generator.channel <- base64.StdEncoding.EncodeToString(buf)
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}
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}
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func randomId() string {
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if randomGenerator == nil {
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r := newConcurrentRandom()
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if atomic.CompareAndSwapPointer((*unsafe.Pointer)(unsafe.Pointer(&randomGenerator)), unsafe.Pointer(nil), unsafe.Pointer(r)) {
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go r.run()
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} else {
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close(r.channel)
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}
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}
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return <-randomGenerator.channel
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}
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