internal PdfValue pdfReadObj(PdfReferenceReader reference)
{
try {
if (reference.CompressedObj == null)
{
var reader = new PdfStreamReader(this, _stream, reference.Position);
int id = reader.ReadInt();
int revision = reader.ReadInt();
reader.ReadToken(PdfValueType.ObjectBegin);
if (id != reference.Id || revision != reference.Revision)
{
throw new PdfException("Object id d'not match with xreftable.");
}
var obj = _readObj(reader, false);
if (obj is PdfObjectReader && ((PdfObjectReader)obj).NamedType == "ObjStm")
{
obj = new PdfObjStmReader(this, (PdfObjectReader)obj);
}
return(obj);
}
else
{
if (!(_xrefTable[reference.CompressedObj.Id].Value is PdfObjStmReader objStm))
{
throw new PdfException("Obj not ObjStm.");
}
return(_readObj(new PdfStreamReader(this, objStm.GetStream(reference.Position, reference.Id), 0), true));
}
}
catch (Exception err) {
throw new PdfExceptionReader("Can't read object " + reference.Id.ToString(CultureInfo.InvariantCulture) + "/" + reference.Revision.ToString(CultureInfo.InvariantCulture) + ".", err);
}
}
private void _readXrefObject(int pos, PdfStreamReader reader, PdfValue firstToken)
{
int id = ((PdfInteger)firstToken).Value;
int revision = reader.ReadInt();
reader.ReadToken(PdfValueType.ObjectBegin);
_allocateXrefTable(id + 1);
var rr = new PdfReferenceReader(this, id, revision, pos);
if (!(_readObj(reader, false) is PdfObjectReader obj))
{
throw new PdfExceptionReader("Invalid Xref obj.");
}
rr.setValue(obj);
_xrefTable[id] = rr;
var dictionary = obj.Dictionary.Children;
PdfValueList w = null;
PdfValueList index = null;
int size = 0;
PdfReferenceReader prev = null;
for (int i = 0; i < dictionary.Count; ++i)
{
var entry = dictionary[i];
if (entry is PdfName)
{
switch (((PdfName)entry).Value)
{
case "W": w = ((PdfArray)dictionary[++i]).Children; break;
case "Index": index = ((PdfArray)dictionary[++i]).Children; break;
case "Size": size = ((PdfInteger)dictionary[++i]).Value; break;
case "Prev": prev = (PdfReferenceReader)dictionary[++i]; break;
case "Root": _rootReference = (PdfReferenceReader)dictionary[++i]; break;
case "Encrypt": _encryptReference = (PdfReferenceReader)dictionary[++i]; break;
case "Info": _infoReference = (PdfReferenceReader)dictionary[++i]; break;
case "ID": _id = ((PdfArray)dictionary[++i]).Children.ToArray(); break;
}
}
}
if (obj.NamedType != "XRef" || w == null || index == null)
{
throw new PdfExceptionReader("Invalid xref object.");
}
int s1 = ((PdfInteger)w[0]).Value;
int s2 = ((PdfInteger)w[1]).Value;
int s3 = ((PdfInteger)w[2]).Value;
id = ((PdfInteger)index[0]).Value;
_allocateXrefTable(((PdfInteger)index[1]).Value);
using (var r = new PdfXrefStreamReader(obj.GetUncompressStream())) {
while (!r.EOF)
{
int t = r.ReadValue(s1);
int v2 = r.ReadValue(s2);
int v3 = r.ReadValue(s3);
switch (t)
{
case 0: break;
case 1: pdfGetReference(id, v3).setPosition(v2); break;
case 2: pdfGetReference(id, 0).setCompressed(v3, pdfGetReference(v2, 0)); break;
default: throw new PdfExceptionReader("cross-reference stream type #" + t + " unknown.");
}
++id;
}
}
}
private void _readXrefTable(PdfStreamReader reader)
{
PdfValue Token;
// Read xref table
while ((Token = reader.ReadToken()).Type == PdfValueType.Integer)
{
int Id = ((PdfInteger)Token).Value;
int Count = reader.ReadInt();
_allocateXrefTable(Id + Count);
while (Count-- > 0)
{
int EntryPosition = reader.ReadInt();
int EntryRevision = reader.ReadInt();
bool EntryUsed = (reader.ReadByte() == 'n');
if (EntryPosition >= 10 && EntryUsed)
{
_xrefTable[Id] = new PdfReferenceReader(this, Id, EntryRevision, EntryPosition);
}
++Id;
}
}
// Read trailer
if (Token.Type != PdfValueType.Trailer)
{
throw new PdfExceptionReader("PDF stream corrupt: 'trailer' expected.");
}
reader.ReadToken(PdfValueType.DictionaryBegin);
while ((Token = reader.ReadToken()).Type != PdfValueType.DictionaryEnd)
{
if (Token.Type == PdfValueType.Name)
{
switch (((PdfName)Token).Value)
{
case "Size":
if (reader.ReadInt() != _xrefTable.Length)
{
throw new PdfExceptionReader("PDF stream corrupt: Xref table size d'not match trailer 'Size'.");
}
break;
case "Prev": {
var p = reader.ReadInt();
reader.ReadToken(PdfValueType.Xref);
_readXrefTable(new PdfStreamReader(this, _stream, p));
}
break;
case "Root":
_rootReference = pdfGetReference(reader.ReadReference());
break;
case "Encrypt":
_encryptReference = pdfGetReference(reader.ReadReference());
break;
case "Info":
_infoReference = pdfGetReference(reader.ReadReference());
break;
case "ID": {
List <PdfValue> ID = new List <PdfValue>();
reader.ReadToken(PdfValueType.ArrayBegin);
while ((Token = reader.ReadToken()).Type != PdfValueType.ArrayEnd)
{
ID.Add(Token);
}
_id = ID.ToArray();
}
break;
}
}
}
}