diff options
Diffstat (limited to 'formats/index/encoder.go')
-rw-r--r-- | formats/index/encoder.go | 141 |
1 files changed, 0 insertions, 141 deletions
diff --git a/formats/index/encoder.go b/formats/index/encoder.go deleted file mode 100644 index 94fbc68..0000000 --- a/formats/index/encoder.go +++ /dev/null @@ -1,141 +0,0 @@ -package index - -import ( - "bytes" - "crypto/sha1" - "errors" - "hash" - "io" - "time" - - "gopkg.in/src-d/go-git.v4/utils/binary" -) - -var ( - // EncodeVersionSupported is the range of supported index versions - EncodeVersionSupported uint32 = 2 - - // ErrInvalidTimestamp is returned by Encode if a Index with a Entry with - // negative timestamp values - ErrInvalidTimestamp = errors.New("negative timestamps are not allowed") -) - -// An Encoder writes an Index to an output stream. -type Encoder struct { - w io.Writer - hash hash.Hash -} - -// NewEncoder returns a new encoder that writes to w. -func NewEncoder(w io.Writer) *Encoder { - h := sha1.New() - mw := io.MultiWriter(w, h) - return &Encoder{mw, h} -} - -// Encode writes the Index to the stream of the encoder. -func (e *Encoder) Encode(idx *Index) error { - // TODO: support versions v3 and v4 - // TODO: support extensions - if idx.Version != EncodeVersionSupported { - return ErrUnsupportedVersion - } - - if err := e.encodeHeader(idx); err != nil { - return err - } - - if err := e.encodeEntries(idx); err != nil { - return err - } - - return e.encodeFooter() -} - -func (e *Encoder) encodeHeader(idx *Index) error { - return binary.Write(e.w, - indexSignature, - idx.Version, - uint32(len(idx.Entries)), - ) -} - -func (e *Encoder) encodeEntries(idx *Index) error { - for _, entry := range idx.Entries { - if err := e.encodeEntry(&entry); err != nil { - return err - } - - wrote := entryHeaderLength + len(entry.Name) - if err := e.padEntry(wrote); err != nil { - return err - } - } - - return nil -} - -func (e *Encoder) encodeEntry(entry *Entry) error { - if entry.IntentToAdd || entry.SkipWorktree { - return ErrUnsupportedVersion - } - - sec, nsec, err := e.timeToUint32(&entry.CreatedAt) - if err != nil { - return err - } - - msec, mnsec, err := e.timeToUint32(&entry.ModifiedAt) - if err != nil { - return err - } - - flags := uint16(entry.Stage&0x3) << 12 - if l := len(entry.Name); l < nameMask { - flags |= uint16(l) - } else { - flags |= nameMask - } - - flow := []interface{}{ - sec, nsec, - msec, mnsec, - entry.Dev, - entry.Inode, - entry.Mode, - entry.UID, - entry.GID, - entry.Size, - entry.Hash[:], - flags, - } - - if err := binary.Write(e.w, flow...); err != nil { - return err - } - - return binary.Write(e.w, []byte(entry.Name)) -} - -func (e *Encoder) timeToUint32(t *time.Time) (uint32, uint32, error) { - if t.IsZero() { - return 0, 0, nil - } - - if t.Unix() < 0 || t.UnixNano() < 0 { - return 0, 0, ErrInvalidTimestamp - } - - return uint32(t.Unix()), uint32(t.Nanosecond()), nil -} - -func (e *Encoder) padEntry(wrote int) error { - padLen := 8 - wrote%8 - - _, err := e.w.Write(bytes.Repeat([]byte{'\x00'}, padLen)) - return err -} - -func (e *Encoder) encodeFooter() error { - return binary.Write(e.w, e.hash.Sum(nil)) -} |