108 строки
2.3 KiB
Go
108 строки
2.3 KiB
Go
// Copyright 2019 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build !js
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// +build !js
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// js does not support inter-process file locking.
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//nolint
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package lockedfile_test
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import (
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"bytes"
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"encoding/binary"
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"math/rand"
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"path/filepath"
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"testing"
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"time"
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"github.com/Azure/azure-container-networking/internal/lockedfile"
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)
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func isPowerOf2(x int) bool {
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return x > 0 && x&(x-1) == 0
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}
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func roundDownToPowerOf2(x int) int {
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if x <= 0 {
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panic("nonpositive x")
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}
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bit := 1
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for x != bit {
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x = x &^ bit
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bit <<= 1
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}
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return x
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}
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func TestTransform(t *testing.T) {
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dir, remove := mustTempDir(t)
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defer remove()
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path := filepath.Join(dir, "blob.bin")
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const maxChunkWords = 8 << 10
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buf := make([]byte, 2*maxChunkWords*8)
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for i := uint64(0); i < 2*maxChunkWords; i++ {
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binary.LittleEndian.PutUint64(buf[i*8:], i)
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}
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if err := lockedfile.Write(path, bytes.NewReader(buf[:8]), 0666); err != nil {
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t.Fatal(err)
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}
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var attempts int64 = 128
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if !testing.Short() {
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attempts *= 16
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}
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const parallel = 32
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var sem = make(chan bool, parallel)
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for n := attempts; n > 0; n-- {
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sem <- true
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go func() {
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defer func() { <-sem }()
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time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
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chunkWords := roundDownToPowerOf2(rand.Intn(maxChunkWords) + 1)
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offset := rand.Intn(chunkWords)
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err := lockedfile.Transform(path, func(data []byte) (chunk []byte, err error) {
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chunk = buf[offset*8 : (offset+chunkWords)*8]
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if len(data)&^7 != len(data) {
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t.Errorf("read %d bytes, but each write is an integer multiple of 8 bytes", len(data))
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return chunk, nil
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}
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words := len(data) / 8
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if !isPowerOf2(words) {
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t.Errorf("read %d 8-byte words, but each write is a power-of-2 number of words", words)
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return chunk, nil
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}
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u := binary.LittleEndian.Uint64(data)
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for i := 1; i < words; i++ {
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next := binary.LittleEndian.Uint64(data[i*8:])
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if next != u+1 {
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t.Errorf("wrote sequential integers, but read integer out of sequence at offset %d", i)
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return chunk, nil
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}
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u = next
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}
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return chunk, nil
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})
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if err != nil {
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t.Errorf("unexpected error from Transform: %v", err)
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}
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}()
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}
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for n := parallel; n > 0; n-- {
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sem <- true
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}
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}
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