public static PDFFileIndirectObject Parse(PDFTextSearcher searcher, int number, int gen)
{
string start = number.ToString() + " " + gen.ToString() + " obj";
string end = "endobj";
string endstream = "endstream";
string stream = "stream";
string matchstart = searcher.GetInnerText(start.Length);
if (matchstart != start)
{
throw new PDFNativeParserException(string.Format(CommonErrors.IndirectObjectCannotBeParsed, start));
}
long startPos = searcher.Position;
PDFFileRange endobjPos = searcher.MatchForwardString(end);
if (endobjPos.Found == false)
{
throw new PDFNativeParserException(string.Format(CommonErrors.IndirectObjectCannotBeParsed, start));
}
PDFFileRange endstreamPos = searcher.MatchBackwardString(endstream, startPos);
PDFFileRange startstreamPos;
if (endstreamPos.Found)
{
startstreamPos = searcher.MatchBackwardString(stream, startPos);
if (startstreamPos.Found == false)
{
throw new PDFNativeParserException(string.Format(CommonErrors.IndirectObjectCannotBeParsed, start));
}
endobjPos = startstreamPos;
}
else
{
startstreamPos = PDFFileRange.NotFound;
}
int length = (int)(endobjPos.StartOffset - startPos);
string data = searcher.GetInnerText(startPos, length);
PDFFileIndirectObject parsed = new PDFFileIndirectObject(number, gen, data);
parsed._offset = startPos;
if (startstreamPos.Found)
{
parsed.SetStreamData(searcher.GetInnerBytes(startstreamPos, endstreamPos));
}
parsed.EnsureDataParsed();
return(parsed);
}
//
// public methods
//
#region public IIndirectObject GetIndirectObject(PDFObjectRef oref)
/// <summary>
/// Reads and returns the object data returned based on the provided reference
/// </summary>
/// <param name="oref"></param>
/// <returns></returns>
public override IParsedIndirectObject GetObject(PDFObjectRef oref)
{
PDFXRefTableEntry entry = this.XRefTable[oref];
if (null != entry)
{
if (entry.Free == false)
{
if (null == entry.Reference)
{
this.Searcher.Position = entry.Offset;
entry.Reference = PDFFileIndirectObject.Parse(this.Searcher, oref.Number, oref.Generation);
}
return((IParsedIndirectObject)entry.Reference);
}
}
return(null);
}
/// <summary>
/// Initializes the known PDF file data such as trailers, xref tables and catalogs
/// </summary>
protected override void InitData(PDFTraceLog log)
{
try
{
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "Finding end of file, startxref and trailer positions");
}
this.Searcher.Position = this.Searcher.Length;
PDFFileRange eofPos = AssertFoundRange(Searcher.MatchBackwardString(EndOfFileMarker), EndOfFileMarker);
PDFFileRange startxrefPos = AssertFoundRange(Searcher.MatchBackwardString(StartXRefMarker), StartXRefMarker);
PDFFileRange trailerPos = AssertFoundRange(Searcher.MatchBackwardString(TrailerMarker), TrailerMarker);
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "Markers found, loading the trailer dictionary");
}
PDFDictionary trailer = GetTrailerDictionary(trailerPos, startxrefPos);
this._trailer = trailer;
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "Markers found, loading the XRef table");
}
PDFObjectRef catalogRef = AssertGetObjectRef(trailer, CatalogObjName, "The '" + CatalogObjName + "' entry couldnot be found in the documents trailer dictionary");
PDFObjectRef infoRef = AssertGetObjectRef(trailer, InfoObjName, "The '" + InfoObjName + "' entry couldnot be found in the documents trailer dictionary");
IFileObject prevXRefObj;
trailer.TryGetValue(PrevXRefName, out prevXRefObj);
long prevOffset = -1;
if (prevXRefObj is PDFNumber)
{
prevOffset = ((PDFNumber)prevXRefObj).Value;
}
else if (prevXRefObj is PDFReal)
{
prevOffset = (long)((PDFNumber)prevXRefObj).Value;
}
PDFXRefTable xref = GetXRefTable(startxrefPos, eofPos, prevOffset);
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "References for the catalog and document info found");
}
this._xreftable = xref;
this._info = (PDFFileIndirectObject)this.GetObject(infoRef);
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "Loaded the document Info indirect object");
}
this._catalog = (PDFFileIndirectObject)this.GetObject(catalogRef);
if (log.ShouldLog(TraceLevel.Debug))
{
log.Add(TraceLevel.Debug, "PDFReader", "Loaded the document Catalog indirect object");
}
//TODO: Look for more updates and read those in too
}
catch (Exception ex)
{
throw new PDFNativeParserException(CommonErrors.CouldNotInitializeThePDFReader, ex);
}
}