mirror of https://github.com/chaos-mesh/toda.git
92 lines
2.0 KiB
Go
92 lines
2.0 KiB
Go
// Copyright 2020 Chaos Mesh Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package main
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strconv"
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"syscall"
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"time"
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)
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func main() {
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content := make([]byte, 10)
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content = append(content, []byte("HELLO WORLD000")...)
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err := ioutil.WriteFile("/var/run/test/test", content, 0644)
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if err != nil {
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fmt.Printf("Error: %v+", err)
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return
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}
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originalLength := len([]byte("HELLO WORLD"))
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for {
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var fVec []*os.File
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var mMap [][]byte
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for i := 0; i < 100; i++ {
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f, err := os.OpenFile("/var/run/test/test", os.O_RDWR, 0666)
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if err != nil {
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fmt.Printf("Error: %v+", err)
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return
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}
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err = f.Truncate(1024)
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if err != nil {
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fmt.Printf("Error: %v\n", err)
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continue
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}
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_, err = f.Seek(10, os.SEEK_SET)
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if err != nil {
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fmt.Printf("Error: %v\n", err)
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continue
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}
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fVec = append(fVec, f)
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data, err := syscall.Mmap(int(f.Fd()), 0, 10+originalLength+3, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
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if err != nil {
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fmt.Printf("Error: %v+", err)
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return
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}
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mMap = append(mMap, data)
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f = fVec[i]
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data = mMap[i]
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count := strconv.Itoa(i)
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for pos, char := range count {
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if pos < 3 {
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data[10+originalLength+pos] = byte(char)
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}
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}
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time.Sleep(time.Second)
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buf := make([]byte, originalLength+len(count))
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n, err := f.Read(buf)
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if err != nil {
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fmt.Printf("Error: %v\n", err)
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continue
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}
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fmt.Printf("%v %d bytes: %s\n", time.Now(), n, string(buf[:n]))
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}
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for i := 0; i < 100; i++ {
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fVec[i].Close()
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syscall.Munmap(mMap[i])
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}
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}
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}
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