private CosBase ReadNormalObjectStream(IRandomAccessRead reader, CosBase currentBase, long offset,
bool isLenientParsing,
out string endObjectKey)
{
if (currentBase is PdfDictionary dictionary)
{
PdfRawStream stream = streamParser.Parse(reader, dictionary, isLenientParsing, null);
currentBase = stream;
}
else
{
// this is not legal
// the combination of a dict and the stream/endstream
// forms a complete stream object
throw new InvalidOperationException($"Stream not preceded by dictionary (offset: {offset}).");
}
ReadHelper.SkipSpaces(reader);
endObjectKey = ReadHelper.ReadLine(reader);
// we have case with a second 'endstream' before endobj
if (!endObjectKey.StartsWith("endobj") && endObjectKey.StartsWith("endstream"))
{
endObjectKey = endObjectKey.Substring(9).Trim();
if (endObjectKey.Length == 0)
{
// no other characters in extra endstream line
// read next line
endObjectKey = ReadHelper.ReadLine(reader);
}
}
return(currentBase);
}
public static CosBase GetDictionaryObject(this PdfDictionary dictionary, CosName firstKey, CosName secondKey)
{
CosBase result = dictionary.GetDictionaryObject(firstKey);
if (result == null && secondKey != null)
{
result = dictionary.GetDictionaryObject(secondKey);
}
return(result);
}
private ICosNumber GetLength(IRandomAccessRead source, CosBase lengthBaseObj, CosName streamType, bool isLenientParsing, IPdfObjectParser parser)
{
if (lengthBaseObj == null)
{
return(null);
}
// Length is given directly in the stream dictionary
if (lengthBaseObj is ICosNumber number)
{
return(number);
}
// length in referenced object
if (lengthBaseObj is CosObject lengthObj)
{
var currentObject = lengthObj.GetObject();
if (currentObject == null)
{
if (parser == null)
{
throw new InvalidOperationException("This method required access to the PDF object parser but it was not created yet. Figure out how to fix this.");
}
var currentOffset = source.GetPosition();
var obj = parser.Parse(lengthObj.ToIndirectReference(), source, isLenientParsing);
source.Seek(currentOffset);
if (obj is ICosNumber referenceNumber)
{
return(referenceNumber);
}
throw new InvalidOperationException("Length object content was not read.");
}
if (currentObject is ICosNumber objectNumber)
{
return(objectNumber);
}
throw new InvalidOperationException("Wrong type of referenced length object " + lengthObj
+ ": " + lengthObj.GetObject().GetType().Name);
}
throw new InvalidOperationException($"Wrong type of length object: {lengthBaseObj.GetType().Name}");
}
public CosBase Parse(IRandomAccessRead reader, CosObjectPool pool)
{
CosBase retval = null;
ReadHelper.SkipSpaces(reader);
int nextByte = reader.Peek();
if (nextByte == -1)
{
return(null);
}
char c = (char)nextByte;
switch (c)
{
case '<':
{
// pull off first left bracket
int leftBracket = reader.Read();
// check for second left bracket
c = (char)reader.Peek();
reader.Unread(leftBracket);
if (c == '<')
{
retval = dictionaryParser.Parse(reader, this, pool);
ReadHelper.SkipSpaces(reader);
}
else
{
retval = stringParser.Parse(reader);
}
break;
}
case '[':
{
// array
retval = arrayParser.Parse(reader, this, pool);
break;
}
case '(':
retval = stringParser.Parse(reader);
break;
case '/':
// name
retval = nameParser.Parse(reader);
break;
case 'n':
{
// null
ReadHelper.ReadExpectedString(reader, "null");
retval = CosNull.Null;
break;
}
case 't':
{
string truestring = OtherEncodings.BytesAsLatin1String(reader.ReadFully(4));
if (truestring.Equals("true"))
{
retval = PdfBoolean.True;
}
else
{
throw new IOException("expected true actual='" + truestring + "' " + reader +
"' at offset " + reader.GetPosition());
}
break;
}
case 'f':
{
string falsestring = OtherEncodings.BytesAsLatin1String(reader.ReadFully(5));
if (falsestring.Equals("false"))
{
retval = PdfBoolean.False;
}
else
{
throw new IOException("expected false actual='" + falsestring + "' " + reader +
"' at offset " + reader.GetPosition());
}
break;
}
case 'R':
reader.Read();
retval = new CosObject(null);
break;
default:
if (char.IsDigit(c) || c == '-' || c == '+' || c == '.')
{
StringBuilder buf = new StringBuilder();
int ic = reader.Read();
c = (char)ic;
while (char.IsDigit(c) ||
c == '-' ||
c == '+' ||
c == '.' ||
c == 'E' ||
c == 'e')
{
buf.Append(c);
ic = reader.Read();
c = (char)ic;
}
if (ic != -1)
{
reader.Unread(ic);
}
retval = CosNumberFactory.get(buf.ToString()) as CosBase;
}
else
{
//This is not suppose to happen, but we will allow for it
//so we are more compatible with POS writers that don't
//follow the spec
string badstring = ReadHelper.ReadString(reader);
if (badstring == string.Empty)
{
int peek = reader.Peek();
// we can end up in an infinite loop otherwise
throw new IOException("Unknown dir object c='" + c +
"' cInt=" + (int)c + " peek='" + (char)peek
+ "' peekInt=" + peek + " at offset " + reader.GetPosition());
}
// if it's an endstream/endobj, we want to put it back so the caller will see it
if (string.Equals("endobj", badstring) || string.Equals("endstream", badstring))
{
reader.Unread(OtherEncodings.StringAsLatin1Bytes(badstring));
}
}
break;
}
return(retval);
}
