PDFsharp & MigraDoc Foundation

Parser.cs

ReadTrailer()

    /// <summary>
    /// Reads the iref table and the trailer dictionary.
    /// </summary>
    internal PdfTrailer ReadTrailer()
    {
      //Symbol symbol;
      //string token;
      //int xrefOffset = 0;
      int length = lexer.PdfLength;

      int offset = 0;
#if true
      offset = 130;
#else
      offset = 30;
#endif

      string trail = this.lexer.ReadRawString(length - offset - 1, offset); //lexer.Pdf.Substring(length - 30);
      int idx = trail.IndexOf("startxref");
      if (idx < 0)
      {
        trail = this.lexer.ReadRawString(0, length);
        idx = trail.LastIndexOf("startxref");
        // maybe still not found, but ignore it
        this.lexer.Position = idx;
      }
      else
      {
        this.lexer.Position = length - offset - 1 + idx;
      }

      ReadSymbol(Symbol.StartXRef);
      this.lexer.Position = ReadInteger();

      // Read all trailers
      PdfTrailer trailer;
      while (true)
      {
        trailer = ReadXRefTableAndTrailer(this.document.irefTable);
        // 1st trailer seems to be the best..
        if (this.document.trailer == null)
          this.document.trailer = trailer;
        int prev = trailer.Elements.GetInteger(PdfTrailer.Keys.Prev);
        if (prev == 0)
          break;
        //if (prev > this.lexer.PdfLength)
        //  break;
        this.lexer.Position = prev;
      }

      return this.document.trailer;
    }