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all: split zip out into subpackage
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Building on the discussion in mholt#180, this is a way for callers to be
able to use the zip package directly without importing the other
compression/decompression packages. It uses aliases to preserve
backwards compatibility.

The utility functions and types used by the zip package needed to
be split out into a subpackage as well (named "common") to avoid a
circular dependency issue.
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@kevinburke
kevinburke committed Dec 23, 2020
1 parent 699ca56 commit 96b4191
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Showing 22 changed files with 1,236 additions and 1,168 deletions.
187 changes: 11 additions & 176 deletions archiver.go
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Original file line number Diff line number Diff line change
Expand Up @@ -48,10 +48,9 @@ import (
"fmt"
"io"
"os"
"path"
"path/filepath"
"runtime"
"strings"

"github.com/mholt/archiver/v3/common"
)

// Archiver is a type that can create an archive file
Expand All @@ -67,6 +66,9 @@ type Archiver interface {
Archive(sources []string, destination string) error
}

type File = common.File
type FileInfo = common.FileInfo

// ExtensionChecker validates file extensions
type ExtensionChecker interface {
CheckExt(name string) error
Expand All @@ -87,15 +89,15 @@ type Unarchiver interface {
// an output stream.
type Writer interface {
Create(out io.Writer) error
Write(f File) error
Write(f common.File) error
Close() error
}

// Reader can read discrete byte streams of files from
// an input stream.
type Reader interface {
Open(in io.Reader, size int64) error
Read() (File, error)
Read() (common.File, error)
Close() error
}

Expand All @@ -105,37 +107,6 @@ type Extractor interface {
Extract(source, target, destination string) error
}

// File provides methods for accessing information about
// or contents of a file within an archive.
type File struct {
os.FileInfo

// The original header info; depends on
// type of archive -- could be nil, too.
Header interface{}

// Allow the file contents to be read (and closed)
io.ReadCloser
}

// FileInfo is an os.FileInfo but optionally with
// a custom name, useful if dealing with files that
// are not actual files on disk, or which have a
// different name in an archive than on disk.
type FileInfo struct {
os.FileInfo
CustomName string
}

// Name returns fi.CustomName if not empty;
// otherwise it returns fi.FileInfo.Name().
func (fi FileInfo) Name() string {
if fi.CustomName != "" {
return fi.CustomName
}
return fi.FileInfo.Name()
}

// ReadFakeCloser is an io.Reader that has
// a no-op close method to satisfy the
// io.ReadCloser interface.
Expand All @@ -149,18 +120,11 @@ func (rfc ReadFakeCloser) Close() error { return nil }
// Walker can walk an archive file and return information
// about each item in the archive.
type Walker interface {
Walk(archive string, walkFn WalkFunc) error
Walk(archive string, walkFn common.WalkFunc) error
}

// WalkFunc is called at each item visited by Walk.
// If an error is returned, the walk may continue
// if the Walker is configured to continue on error.
// The sole exception is the error value ErrStopWalk,
// which stops the walk without an actual error.
type WalkFunc func(f File) error

// ErrStopWalk signals Walk to break without error.
var ErrStopWalk = fmt.Errorf("walk stopped")
var ErrStopWalk = common.ErrStopWalk

// ErrFormatNotRecognized is an error that will be
// returned if the file is not a valid archive format.
Expand Down Expand Up @@ -216,7 +180,7 @@ func Unarchive(source, destination string) error {

// Walk calls walkFn for each file within the given archive file.
// The archive format is chosen implicitly.
func Walk(archive string, walkFn WalkFunc) error {
func Walk(archive string, walkFn common.WalkFunc) error {
wIface, err := ByExtension(archive)
if err != nil {
return err
Expand Down Expand Up @@ -273,64 +237,6 @@ func DecompressFile(source, destination string) error {
return FileCompressor{Decompressor: c}.DecompressFile(source, destination)
}

func fileExists(name string) bool {
_, err := os.Stat(name)
return !os.IsNotExist(err)
}

func mkdir(dirPath string, dirMode os.FileMode) error {
err := os.MkdirAll(dirPath, dirMode)
if err != nil {
return fmt.Errorf("%s: making directory: %v", dirPath, err)
}
return nil
}

func writeNewFile(fpath string, in io.Reader, fm os.FileMode) error {
err := os.MkdirAll(filepath.Dir(fpath), 0755)
if err != nil {
return fmt.Errorf("%s: making directory for file: %v", fpath, err)
}

out, err := os.Create(fpath)
if err != nil {
return fmt.Errorf("%s: creating new file: %v", fpath, err)
}
defer out.Close()

err = out.Chmod(fm)
if err != nil && runtime.GOOS != "windows" {
return fmt.Errorf("%s: changing file mode: %v", fpath, err)
}

_, err = io.Copy(out, in)
if err != nil {
return fmt.Errorf("%s: writing file: %v", fpath, err)
}
return nil
}

func writeNewSymbolicLink(fpath string, target string) error {
err := os.MkdirAll(filepath.Dir(fpath), 0755)
if err != nil {
return fmt.Errorf("%s: making directory for file: %v", fpath, err)
}

_, err = os.Lstat(fpath)
if err == nil {
err = os.Remove(fpath)
if err != nil {
return fmt.Errorf("%s: failed to unlink: %+v", fpath, err)
}
}

err = os.Symlink(target, fpath)
if err != nil {
return fmt.Errorf("%s: making symbolic link for: %v", fpath, err)
}
return nil
}

func writeNewHardLink(fpath string, target string) error {
err := os.MkdirAll(filepath.Dir(fpath), 0755)
if err != nil {
Expand All @@ -352,85 +258,14 @@ func writeNewHardLink(fpath string, target string) error {
return nil
}

func isSymlink(fi os.FileInfo) bool {
return fi.Mode()&os.ModeSymlink != 0
}

// within returns true if sub is within or equal to parent.
func within(parent, sub string) bool {
rel, err := filepath.Rel(parent, sub)
if err != nil {
return false
}
return !strings.Contains(rel, "..")
}

// multipleTopLevels returns true if the paths do not
// share a common top-level folder.
func multipleTopLevels(paths []string) bool {
if len(paths) < 2 {
return false
}
var lastTop string
for _, p := range paths {
p = strings.TrimPrefix(strings.Replace(p, `\`, "/", -1), "/")
for {
next := path.Dir(p)
if next == "." {
break
}
p = next
}
if lastTop == "" {
lastTop = p
}
if p != lastTop {
return true
}
}
return false
}

// folderNameFromFileName returns a name for a folder
// that is suitable based on the filename, which will
// be stripped of its extensions.
func folderNameFromFileName(filename string) string {
base := filepath.Base(filename)
firstDot := strings.Index(base, ".")
if firstDot > -1 {
return base[:firstDot]
}
return base
}

// makeNameInArchive returns the filename for the file given by fpath to be used within
// the archive. sourceInfo is the FileInfo obtained by calling os.Stat on source, and baseDir
// is an optional base directory that becomes the root of the archive. fpath should be the
// unaltered file path of the file given to a filepath.WalkFunc.
func makeNameInArchive(sourceInfo os.FileInfo, source, baseDir, fpath string) (string, error) {
name := filepath.Base(fpath) // start with the file or dir name
if sourceInfo.IsDir() {
// preserve internal directory structure; that's the path components
// between the source directory's leaf and this file's leaf
dir, err := filepath.Rel(filepath.Dir(source), filepath.Dir(fpath))
if err != nil {
return "", err
}
// prepend the internal directory structure to the leaf name,
// and convert path separators to forward slashes as per spec
name = path.Join(filepath.ToSlash(dir), name)
}
return path.Join(baseDir, name), nil // prepend the base directory
}

// NameInArchive returns a name for the file at fpath suitable for
// the inside of an archive. The source and its associated sourceInfo
// is the path where walking a directory started, and if no directory
// was walked, source may == fpath. The returned name is essentially
// the components of the path between source and fpath, preserving
// the internal directory structure.
func NameInArchive(sourceInfo os.FileInfo, source, fpath string) (string, error) {
return makeNameInArchive(sourceInfo, source, "", fpath)
return common.MakeNameInArchive(sourceInfo, source, "", fpath)
}

// ByExtension returns an archiver and unarchiver, or compressor
Expand Down
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