podman/pkg/machine/compression/decompress.go

114 lines
3.5 KiB
Go

package compression
import (
"errors"
"io"
"os"
"path/filepath"
"runtime"
"strings"
"github.com/containers/podman/v5/pkg/machine/define"
"github.com/containers/podman/v5/utils"
"github.com/containers/storage/pkg/archive"
"github.com/sirupsen/logrus"
)
const (
decompressedFileFlag = os.O_CREATE | os.O_TRUNC | os.O_WRONLY
macOs = "darwin"
progressBarPrefix = "Extracting compressed file"
zipExt = ".zip"
)
type decompressor interface {
compressedFileSize() int64
compressedFileMode() os.FileMode
compressedFileReader() (io.ReadCloser, error)
decompress(w WriteSeekCloser, r io.Reader) error
close()
}
func Decompress(compressedVMFile *define.VMFile, decompressedFilePath string) error {
compressedFilePath := compressedVMFile.GetPath()
// Are we reading full image file?
// Only few bytes are read to detect
// the compression type
compressedFileContent, err := compressedVMFile.Read()
if err != nil {
return err
}
var d decompressor
if d, err = newDecompressor(compressedFilePath, compressedFileContent); err != nil {
return err
}
return runDecompression(d, decompressedFilePath)
}
func newDecompressor(compressedFilePath string, compressedFileContent []byte) (decompressor, error) {
compressionType := archive.DetectCompression(compressedFileContent)
os := runtime.GOOS
hasZipSuffix := strings.HasSuffix(compressedFilePath, zipExt)
switch {
case compressionType == archive.Xz:
return newXzDecompressor(compressedFilePath)
// Zip files are not guaranteed to have a magic number at the beginning
// of the file, so we need to use the file name to detect them.
case compressionType == archive.Uncompressed && hasZipSuffix:
return newZipDecompressor(compressedFilePath)
case compressionType == archive.Uncompressed:
return newUncompressedDecompressor(compressedFilePath)
// Using special compressors on MacOS because default ones
// in c/image/pkg/compression are slow with sparse files.
case compressionType == archive.Gzip && os == macOs:
return newGzipDecompressor(compressedFilePath)
case compressionType == archive.Zstd && os == macOs:
return newZstdDecompressor(compressedFilePath)
default:
return newGenericDecompressor(compressedFilePath)
}
}
func runDecompression(d decompressor, decompressedFilePath string) error {
compressedFileReader, err := d.compressedFileReader()
if err != nil {
return err
}
defer d.close()
initMsg := progressBarPrefix + ": " + filepath.Base(decompressedFilePath)
finalMsg := initMsg + ": done"
p, bar := utils.ProgressBar(initMsg, d.compressedFileSize(), finalMsg)
// Wait for bars to complete and then shut down the bars container
defer p.Wait()
compressedFileReaderProxy := bar.ProxyReader(compressedFileReader)
// Interrupts the bar goroutine. It's important that
// bar.Abort(false) is called before p.Wait(), otherwise
// can hang.
defer bar.Abort(false)
var decompressedFileWriter *os.File
if decompressedFileWriter, err = os.OpenFile(decompressedFilePath, decompressedFileFlag, d.compressedFileMode()); err != nil {
logrus.Errorf("Unable to open destination file %s for writing: %q", decompressedFilePath, err)
return err
}
defer func() {
if err := decompressedFileWriter.Close(); err != nil && !errors.Is(err, os.ErrClosed) {
logrus.Warnf("Unable to to close destination file %s: %q", decompressedFilePath, err)
}
}()
if err = d.decompress(decompressedFileWriter, compressedFileReaderProxy); err != nil {
logrus.Errorf("Error extracting compressed file: %q", err)
return err
}
return nil
}