TarReader constructor

TarReader(Stream<List<int>> tarStream, { int maxSpecialFileSize = defaultSpecialLength, bool disallowTrailingData = false, })

Creates a tar reader reading from the raw tarStream.

The disallowTrailingData parameter can be enabled to assert that the tarStream contains exactly one tar archive before ending. When disallowTrailingData is disabled (which is the default), the reader will automatically cancel its stream subscription when moveNext returns false. When it is enabled and a marker indicating the end of an archive is encountered, moveNext will wait for further events on the stream. If further data is received, a TarException will be thrown and the subscription will be cancelled. Otherwise, moveNext effectively waits for a done event, making a cancellation unnecessary. Depending on the input stream, cancellations may cause unintended side-effects. In that case, disallowTrailingData can be used to ensure that the stream is only cancelled if it emits an invalid tar file.

The maxSpecialFileSize parameter can be used to limit the maximum length of hidden entries in the tar stream. These entries include extended PAX headers or long names in GNU tar. The content of those entries has to be buffered in the parser to properly read the following tar entries. To avoid memory-based denial-of-service attacks, this library limits their maximum length. Changing the default of 2 KiB is rarely necessary.

Implementation

TarReader(Stream<List<int>> tarStream,
    {int maxSpecialFileSize = defaultSpecialLength,
    bool disallowTrailingData = false})
    : _reader = BlockReader(tarStream),
      _checkNoTrailingData = disallowTrailingData,
      _maxSpecialFileSize = maxSpecialFileSize;