wal-g

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package utility
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import (
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	"archive/tar"
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	"io"
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	"os"
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	"path/filepath"
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	"strings"
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	"github.com/pkg/errors"
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	"github.com/wal-g/tracelog"
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)
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func GetLocalFile(targetPath string, header *tar.Header) (localFile *os.File, isNewFile bool, err error) {
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	if localFileInfo, _ := GetLocalFileInfo(targetPath); localFileInfo != nil {
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		localFile, err = os.OpenFile(targetPath, os.O_RDWR, 0666)
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	} else {
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		localFile, err = CreateLocalFile(targetPath, header.Name)
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		isNewFile = true
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	}
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	return localFile, isNewFile, err
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}
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// get file info by file path
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func GetLocalFileInfo(targetPath string) (fileInfo os.FileInfo, err error) {
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	info, err := os.Stat(targetPath)
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	if os.IsNotExist(err) {
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		return nil, err
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	}
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	if info.IsDir() {
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		return nil, errors.New("requested file is directory. Aborting")
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	}
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	return info, nil
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}
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// create new local file on disk
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func CreateLocalFile(targetPath, name string) (*os.File, error) {
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	err := CreateParentDirs(name, targetPath)
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	if err != nil {
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		return nil, errors.Wrap(err, "failed to create all directories")
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	}
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	file, err := os.OpenFile(targetPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
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	if err != nil {
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		return nil, errors.Wrapf(err, "failed to create new file: '%s'", targetPath)
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	}
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	return file, nil
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}
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// creates parent dirs of the file
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func CreateParentDirs(fileName string, targetPath string) error {
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	if fileName == targetPath {
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		return nil // because it runs in the local directory
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	}
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	base := filepath.Base(fileName)
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	dir := strings.TrimSuffix(targetPath, base)
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	err := os.MkdirAll(dir, 0755)
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	return err
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}
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func WriteLocalFile(fileReader io.Reader, header *tar.Header, localFile *os.File, fsync bool) error {
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	_, err := io.Copy(localFile, fileReader)
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	if err != nil {
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		err1 := os.Remove(localFile.Name())
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		if err1 != nil {
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			tracelog.ErrorLogger.Fatalf("failed to remove localFile '%s' because of error: %v",
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				localFile.Name(), err1)
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		}
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		return errors.Wrap(err, "copy failed")
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	}
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	mode := os.FileMode(header.Mode)
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	if err = localFile.Chmod(mode); err != nil {
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		return errors.Wrap(err, "chmod failed")
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	}
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	if fsync {
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		err = localFile.Sync()
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		return errors.Wrap(err, "fsync failed")
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	}
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	return nil
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}
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func IsDirectoryEmpty(directoryPath string) (bool, error) {
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	var isEmpty = true
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	searchLambda := func(path string, info os.FileInfo, err error) error {
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		if path != directoryPath {
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			isEmpty = false
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			tracelog.InfoLogger.Printf("found file '%s' in directory: '%s'\n", path, directoryPath)
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		}
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		return nil
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	}
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	err := filepath.Walk(directoryPath, searchLambda)
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	return isEmpty, errors.Wrapf(err, "can't check, that directory: '%s' is empty", directoryPath)
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}
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