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51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
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//
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// This Source Code Form is subject to the terms of the MIT License.
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// If a copy of the MIT was not distributed with this file,
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// You can obtain one at https://github.com/gogf/gf.
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package grand
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import (
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"crypto/rand"
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)
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const (
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// Buffer size for uint32 random number.
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bufferChanSize = 10000
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)
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var (
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// bufferChan is the buffer for random bytes,
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// every item storing 4 bytes.
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bufferChan = make(chan []byte, bufferChanSize)
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)
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func init() {
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go asyncProducingRandomBufferBytesLoop()
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}
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// asyncProducingRandomBufferBytes is a named goroutine, which uses a asynchronous goroutine
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// to produce the random bytes, and a buffer chan to store the random bytes.
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// So it has high performance to generate random numbers.
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func asyncProducingRandomBufferBytesLoop() {
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var step int
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for {
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buffer := make([]byte, 1024)
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if n, err := rand.Read(buffer); err != nil {
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panic(err)
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} else {
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// The random buffer from system is very expensive,
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// so fully reuse the random buffer by changing
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// the step with a different number can
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// improve the performance a lot.
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// for _, step = range []int{4, 5, 6, 7} {
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for _, step = range []int{4} {
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for i := 0; i <= n-4; i += step {
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bufferChan <- buffer[i : i+4]
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}
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}
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}
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}
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}
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