func()

in reader.go [93:136]

• 31 lines of code
• 9 McCabe index (conditional complexity)

func (z *Reader) init(r io.ReaderAt, size int64) error {
	end, err := readDirectoryEnd(r, size)
	if err != nil {
		return err
	}
	z.r = r
	// Since the number of directory records is not validated, it is not
	// safe to preallocate z.File without first checking that the specified
	// number of files is reasonable, since a malformed archive may
	// indicate it contains up to 1 << 128 - 1 files. Since each file has a
	// header which will be _at least_ 30 bytes we can safely preallocate
	// if (data size / 30) >= end.directoryRecords.
	if end.directorySize < uint64(size) && (uint64(size)-end.directorySize)/30 >= end.directoryRecords {
		z.File = make([]*File, 0, end.directoryRecords)
	}
	z.Comment = end.comment
	rs := io.NewSectionReader(r, 0, size)
	if _, err = rs.Seek(int64(end.directoryOffset), io.SeekStart); err != nil {
		return err
	}
	buf := bufio.NewReader(rs)

	// The count of files inside a zip is truncated to fit in a uint16.
	// Gloss over this by reading headers until we encounter
	// a bad one, and then only report an ErrFormat or UnexpectedEOF if
	// the file count modulo 65536 is incorrect.
	for {
		f := &File{zip: z, zipr: r}
		err = readDirectoryHeader(f, buf)
		if err == ErrFormat || err == io.ErrUnexpectedEOF {
			break
		}
		if err != nil {
			return err
		}
		z.File = append(z.File, f)
	}
	if uint16(len(z.File)) != uint16(end.directoryRecords) { // only compare 16 bits here
		// Return the readDirectoryHeader error if we read
		// the wrong number of directory entries.
		return err
	}
	return nil
}