testing/hooks/tmpdir.go - main - krepost/deckhouse

testing/hooks/tmpdir.go
123 строки2 KB
Pavel Okhlopkov
[deckhouse-controller] prepare to add wrapcheck linter (#16429)
20 янв 2026, 17:09
20 янв 2026, 17:092c3f0a3
/*
Copyright 2021 Flant JSC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package hooks

import (
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"time"
)

var rand uint32
var randmu sync.Mutex

func reseed() uint32 {
	return uint32(time.Now().UnixNano() + int64(os.Getpid()))
}

func nextRandom() string {
	randmu.Lock()
	r := rand
	if r == 0 {
		r = reseed()
	}
	r = r*1664525 + 1013904223 // constants from Numerical Recipes
	rand = r
	randmu.Unlock()
	return strconv.Itoa(int(1e9 + r%1e9))[1:]
}

func TempFileWithPerms(dir, pattern string, perms int) (*os.File, error) {
	if dir == "" {
		dir = os.TempDir()
	}

	var prefix, suffix string
	if pos := strings.LastIndex(pattern, "*"); pos != -1 {
		prefix, suffix = pattern[:pos], pattern[pos+1:]
	} else {
		prefix = pattern
	}

	var (
		nconflict = 0
		f         = new(os.File)
		err       error
	)

	for i := 0; i < 10000; i++ {
		name := filepath.Join(dir, prefix+nextRandom()+suffix)
		f, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, os.FileMode(perms))
		if os.IsExist(err) {
			if nconflict++; nconflict > 10 {
				randmu.Lock()
				rand = reseed()
				randmu.Unlock()
			}
			continue
		}
		break
	}

	if err != nil {
		return f, fmt.Errorf("open file: %w", err)
	}
	return f, nil
}

func TempDirWithPerms(dir, prefix string, perms int) (string, error) {
	if dir == "" {
		dir = os.TempDir()
	}

	var (
		nconflict = 0
		err       error
		name      string
	)

	for i := 0; i < 10000; i++ {
		try := filepath.Join(dir, prefix+nextRandom())
		err = os.Mkdir(try, os.FileMode(perms))
		if os.IsExist(err) {
			if nconflict++; nconflict > 10 {
				randmu.Lock()
				rand = reseed()
				randmu.Unlock()
			}
			continue
		}
		if os.IsNotExist(err) {
			if _, err := os.Stat(dir); os.IsNotExist(err) {
				return "", fmt.Errorf("stat: %w", err)
			}
		}
		if err == nil {
			name = try
		}
		break
	}

	if err != nil {
		return name, fmt.Errorf("mkdir: %w", err)
	}
	return name, nil
}