ConstructedOctetStream.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » C# / CSharp Open Source

using System.IO;

using Org.BouncyCastle.Utilities.IO;

namespace Org.BouncyCastle.Asn1{
  internal class ConstructedOctetStream
    : BaseInputStream
  {
    private readonly Asn1StreamParser _parser;

    private bool _first = true;
    private Stream _currentStream;

    internal ConstructedOctetStream(
      Asn1StreamParser parser)
    {
      _parser = parser;
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
      if (_currentStream == null)
      {
        if (!_first)
          return 0;

        Asn1OctetStringParser s = (Asn1OctetStringParser)_parser.ReadObject();

        if (s == null)
          return 0;

        _first = false;
        _currentStream = s.GetOctetStream();
      }

      int totalRead = 0;

      for (;;)
      {
        int numRead = _currentStream.Read(buffer, offset + totalRead, count - totalRead);

        if (numRead > 0)
        {
          totalRead += numRead;

          if (totalRead == count)
            return totalRead;
        }
        else
        {
          Asn1OctetStringParser aos = (Asn1OctetStringParser)_parser.ReadObject();

          if (aos == null)
          {
            _currentStream = null;
            return totalRead;
          }

          _currentStream = aos.GetOctetStream();
        }
      }
    }

    public override int ReadByte()
    {
      if (_currentStream == null)
      {
        if (!_first)
          return 0;

        Asn1OctetStringParser s = (Asn1OctetStringParser)_parser.ReadObject();

        if (s == null)
          return 0;

        _first = false;
        _currentStream = s.GetOctetStream();
      }

      for (;;)
      {
        int b = _currentStream.ReadByte();

        if (b >= 0)
        {
          return b;
        }

        Asn1OctetStringParser aos = (Asn1OctetStringParser)_parser.ReadObject();

        if (aos == null)
        {
          _currentStream = null;
          return -1;
        }

        _currentStream = aos.GetOctetStream();
      }
    }
  }
}