site/vendor/layeh.com/asar/entry.go

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2017-01-09 21:41:39 +00:00
package asar // import "layeh.com/asar"
import (
"errors"
"io"
"io/ioutil"
"os"
"path/filepath"
"strings"
"time"
)
// Flag is a bit field of Entry flags.
type Flag uint32
const (
// FlagNone denotes an entry with no flags.
FlagNone Flag = 0
// FlagDir denotes a directory entry.
FlagDir Flag = 1 << iota
// FlagExecutable denotes a file with the executable bit set.
FlagExecutable
// FlagUnpacked denotes that the entry's contents are not included in
// the archive.
FlagUnpacked
)
// Entry is a file or a folder in an ASAR archive.
type Entry struct {
Name string
Size int64
Offset int64
Flags Flag
Parent *Entry
Children []*Entry
r io.ReaderAt
baseOffset int64
}
// New creates a new Entry.
func New(name string, ra io.ReaderAt, size, offset int64, flags Flag) *Entry {
return &Entry{
Name: name,
Size: size,
Offset: offset,
Flags: flags,
r: ra,
}
}
// FileInfo returns the os.FileInfo information about the entry.
func (e *Entry) FileInfo() os.FileInfo {
return fileInfo{e}
}
type fileInfo struct {
e *Entry
}
func (f fileInfo) Name() string {
return f.e.Name
}
func (f fileInfo) Size() int64 {
return f.e.Size
}
func (f fileInfo) Mode() os.FileMode {
if f.e.Flags&FlagDir != 0 {
return 0555 | os.ModeDir
}
if f.e.Flags&FlagExecutable != 0 {
return 0555
}
return 0444
}
func (f fileInfo) ModTime() time.Time {
return time.Time{}
}
func (f fileInfo) IsDir() bool {
return f.e.Flags&FlagDir != 0
}
func (f fileInfo) Sys() interface{} {
return f.e
}
// Path returns the file path to the entry.
//
// For example, given the following tree structure:
// root
// - sub1
// - sub2
// - file2.jpg
//
// file2.jpg's path would be:
// sub2/file2.jpg
func (e *Entry) Path() string {
if e.Parent == nil {
return ""
}
var p []string
for e != nil && e.Parent != nil {
p = append(p, e.Name)
e = e.Parent
}
l := len(p) / 2
for i := 0; i < l; i++ {
j := len(p) - i - 1
p[i], p[j] = p[j], p[i]
}
return strings.Join(p, "/")
}
// Open returns an *io.SectionReader of the entry's contents. nil is returned if
// the entry cannot be opened (e.g. because it is a directory).
func (e *Entry) Open() *io.SectionReader {
if e.Flags&FlagDir != 0 || e.Flags&FlagUnpacked != 0 {
return nil
}
return io.NewSectionReader(e.r, e.baseOffset+e.Offset, e.Size)
}
// WriteTo writes the entry's contents to the given writer. If the entry cannot
// be opened (e.g. if the entry is a directory).
func (e *Entry) WriteTo(w io.Writer) (n int64, err error) {
r := e.Open()
if r == nil {
return 0, errors.New("asar: entry cannot be opened")
}
return io.Copy(w, r)
}
// Bytes returns the entry's contents as a byte slice. nil is returned if the
// entry cannot be read.
func (e *Entry) Bytes() []byte {
body := e.Open()
if body == nil {
return nil
}
b, err := ioutil.ReadAll(body)
if err != nil {
return nil
}
return b
}
// Bytes returns the entry's contents as a string. nil is returned if the entry
// cannot be read.
func (e *Entry) String() string {
body := e.Bytes()
if body == nil {
return ""
}
return string(body)
}
// Find searches for a sub-entry of the current entry. nil is returned if the
// requested sub-entry cannot be found.
//
// For example, given the following tree structure:
// root
// - sub1
// - sub2
// - sub2.1
// - file2.jpg
//
// The following expression would return the .jpg *Entry:
// root.Find("sub2", "sub2.1", "file2.jpg")
func (e *Entry) Find(path ...string) *Entry {
pathLoop:
for _, name := range path {
for _, child := range e.Children {
if child.Name == name {
e = child
continue pathLoop
}
}
return nil
}
return e
}
// Walk recursively walks over the entry's children. See filepath.Walk and
// filepath.WalkFunc for more information.
func (e *Entry) Walk(walkFn filepath.WalkFunc) error {
return walk(e, "", walkFn)
}
func walk(e *Entry, parentPath string, walkFn filepath.WalkFunc) error {
for i := 0; i < len(e.Children); i++ {
child := e.Children[i]
childPath := parentPath + child.Name
err := walkFn(childPath, child.FileInfo(), nil)
if err == filepath.SkipDir {
continue
}
if err != nil {
return err
}
if child.Flags&FlagDir == 0 {
continue
}
if err := walk(child, childPath+"/", walkFn); err != nil {
return err
}
}
return nil
}
func validFilename(filename string) bool {
if filename == "." || filename == ".." {
return false
}
return strings.IndexAny(filename, "\x00\\/") == -1
}