Function applyBinaryDeltaFragment

pkg/gitdiff/apply_binary.go:81–113

(dst io.Writer, src io.ReaderAt, frag []byte)

}

func applyBinaryDeltaFragment(dst io.Writer, src io.ReaderAt, frag []byte) error {
	srcSize, delta := readBinaryDeltaSize(frag)
	if err := checkBinarySrcSize(src, srcSize); err != nil {
		return err
	}

	dstSize, delta := readBinaryDeltaSize(delta)

	for len(delta) > 0 {
		op := delta[0]
		if op == 0 {
			return errors.New("invalid delta opcode 0")
		}

		var n int64
		var err error
		switch op & 0x80 {
		case 0x80:
			n, delta, err = applyBinaryDeltaCopy(dst, op, delta[1:], src)
		case 0x00:
			n, delta, err = applyBinaryDeltaAdd(dst, op, delta[1:])
		}
		if err != nil {
			return err
		}
		dstSize -= n
	}

	if dstSize != 0 {
		return errors.New("corrupt binary delta: insufficient or extra data")
	}
	return nil
}

// readBinaryDeltaSize reads a variable length size from a delta-encoded binary
// fragment, returing the size and the unused data. Data is encoded as: