dive-zfs/filetree/changeinfo.go

85 lines
1.4 KiB
Go

package filetree
import (
"archive/tar"
"bytes"
"crypto/md5"
"fmt"
"io"
)
type FileChangeInfo struct {
Path string
Typeflag byte
MD5sum [16]byte
DiffType DiffType
}
type DiffType int
// enum to show whether a file has changed
const (
Unchanged DiffType = iota
Changed
Added
Removed
)
func NewFileChangeInfo(reader *tar.Reader, header *tar.Header, path string) FileChangeInfo {
if header.Typeflag == tar.TypeDir {
return FileChangeInfo{
Path: path,
Typeflag: header.Typeflag,
MD5sum: [16]byte{},
}
}
fileBytes := make([]byte, header.Size)
_, err := reader.Read(fileBytes)
if err != nil && err != io.EOF {
panic(err)
}
return FileChangeInfo{
Path: path,
Typeflag: header.Typeflag,
MD5sum: md5.Sum(fileBytes),
DiffType: Unchanged,
}
}
func (d DiffType) String() string {
switch d {
case Unchanged:
return "Unchanged"
case Changed:
return "Changed"
case Added:
return "Added"
case Removed:
return "Removed"
default:
return fmt.Sprintf("%d", int(d))
}
}
func (a DiffType) merge(b DiffType) DiffType {
if a == b {
return a
}
return Changed
}
func (a *FileChangeInfo) getDiffType(b *FileChangeInfo) DiffType {
if a == nil && b == nil {
return Unchanged
}
if a == nil || b == nil {
return Changed
}
if a.Typeflag == b.Typeflag {
if bytes.Compare(a.MD5sum[:], b.MD5sum[:]) == 0 {
return Unchanged
}
}
return Changed
}