Files
dbbackup/internal/backup/incremental_extract.go
2026-01-24 04:50:22 +01:00

105 lines
2.8 KiB
Go

package backup
import (
"archive/tar"
"context"
"fmt"
"io"
"os"
"path/filepath"
"github.com/klauspost/pgzip"
)
// extractTarGz extracts a tar.gz archive to the specified directory
// Files are extracted with their original permissions and timestamps
func (e *PostgresIncrementalEngine) extractTarGz(ctx context.Context, archivePath, targetDir string) error {
// Open archive file
archiveFile, err := os.Open(archivePath)
if err != nil {
return fmt.Errorf("failed to open archive: %w", err)
}
defer archiveFile.Close()
// Create parallel gzip reader for faster decompression
gzReader, err := pgzip.NewReader(archiveFile)
if err != nil {
return fmt.Errorf("failed to create gzip reader: %w", err)
}
defer gzReader.Close()
// Create tar reader
tarReader := tar.NewReader(gzReader)
// Extract each file
fileCount := 0
for {
// Check context cancellation
select {
case <-ctx.Done():
return ctx.Err()
default:
}
header, err := tarReader.Next()
if err == io.EOF {
break // End of archive
}
if err != nil {
return fmt.Errorf("failed to read tar header: %w", err)
}
// Build target path
targetPath := filepath.Join(targetDir, header.Name)
// Ensure parent directory exists
if err := os.MkdirAll(filepath.Dir(targetPath), 0755); err != nil {
return fmt.Errorf("failed to create directory for %s: %w", header.Name, err)
}
switch header.Typeflag {
case tar.TypeDir:
// Create directory
if err := os.MkdirAll(targetPath, os.FileMode(header.Mode)); err != nil {
return fmt.Errorf("failed to create directory %s: %w", header.Name, err)
}
case tar.TypeReg:
// Extract regular file
outFile, err := os.OpenFile(targetPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(header.Mode))
if err != nil {
return fmt.Errorf("failed to create file %s: %w", header.Name, err)
}
if _, err := io.Copy(outFile, tarReader); err != nil {
outFile.Close()
return fmt.Errorf("failed to write file %s: %w", header.Name, err)
}
outFile.Close()
// Preserve modification time
if err := os.Chtimes(targetPath, header.ModTime, header.ModTime); err != nil {
e.log.Warn("Failed to set file modification time", "file", header.Name, "error", err)
}
fileCount++
if fileCount%100 == 0 {
e.log.Debug("Extraction progress", "files", fileCount)
}
case tar.TypeSymlink:
// Create symlink
if err := os.Symlink(header.Linkname, targetPath); err != nil {
// Don't fail on symlink errors - just warn
e.log.Warn("Failed to create symlink", "source", header.Name, "target", header.Linkname, "error", err)
}
default:
e.log.Warn("Unsupported tar entry type", "type", header.Typeflag, "name", header.Name)
}
}
e.log.Info("Archive extracted", "files", fileCount, "archive", filepath.Base(archivePath))
return nil
}