| package remotecontext // import "github.com/docker/docker/builder/remotecontext" |
| |
| import ( |
| "archive/tar" |
| "crypto/sha256" |
| "hash" |
| "os" |
| |
| "github.com/docker/docker/pkg/archive" |
| "github.com/docker/docker/pkg/tarsum" |
| ) |
| |
| // NewFileHash returns new hash that is used for the builder cache keys |
| func NewFileHash(path, name string, fi os.FileInfo) (hash.Hash, error) { |
| var link string |
| if fi.Mode()&os.ModeSymlink != 0 { |
| var err error |
| link, err = os.Readlink(path) |
| if err != nil { |
| return nil, err |
| } |
| } |
| hdr, err := archive.FileInfoHeader(name, fi, link) |
| if err != nil { |
| return nil, err |
| } |
| if err := archive.ReadSecurityXattrToTarHeader(path, hdr); err != nil { |
| return nil, err |
| } |
| tsh := &tarsumHash{hdr: hdr, Hash: sha256.New()} |
| tsh.Reset() // initialize header |
| return tsh, nil |
| } |
| |
| type tarsumHash struct { |
| hash.Hash |
| hdr *tar.Header |
| } |
| |
| // Reset resets the Hash to its initial state. |
| func (tsh *tarsumHash) Reset() { |
| // comply with hash.Hash and reset to the state hash had before any writes |
| tsh.Hash.Reset() |
| tarsum.WriteV1Header(tsh.hdr, tsh.Hash) |
| } |