public CrossReferenceTablePart Parse(ISeekableTokenScanner scanner, long offset, bool isLenientParsing)
{
var builder = new CrossReferenceTablePartBuilder
{
Offset = offset,
XRefType = CrossReferenceType.Table
};
if (scanner.CurrentPosition != offset)
{
scanner.Seek(offset);
}
scanner.MoveNext();
if (scanner.CurrentToken is OperatorToken operatorToken)
{
if (operatorToken.Data == "xref")
{
scanner.MoveNext();
}
else
{
throw new PdfDocumentFormatException($"Unexpected operator in xref position: {operatorToken}.");
}
}
if (scanner.CurrentToken is NumericToken firstObjectNumber)
{
if (!scanner.TryReadToken(out NumericToken objectCount))
{
throw new PdfDocumentFormatException($"Unexpected token following xref and {firstObjectNumber}. We found: {scanner.CurrentToken}.");
}
var definition = new TableSubsectionDefinition(firstObjectNumber.Long, objectCount.Int);
var tokenizer = new EndOfLineTokenizer();
scanner.RegisterCustomTokenizer((byte)'\r', tokenizer);
scanner.RegisterCustomTokenizer((byte)'\n', tokenizer);
var readingLine = false;
var tokens = new List <IToken>();
var count = 0;
while (scanner.MoveNext())
{
if (scanner.CurrentToken is EndOfLineToken)
{
if (!readingLine)
{
continue;
}
readingLine = false;
count = ProcessTokens(tokens, scanner, builder, isLenientParsing, count, ref definition);
tokens.Clear();
continue;
}
if (scanner.CurrentToken is CommentToken)
{
continue;
}
var isLineOperator = scanner.CurrentToken is OperatorToken op && (op.Data == FreeEntry || op.Data == InUseEntry);
if (!(scanner.CurrentToken is NumericToken) && !isLineOperator)
{
break;
}
readingLine = true;
tokens.Add(scanner.CurrentToken);
}
if (tokens.Count > 0)
{
ProcessTokens(tokens, scanner, builder, isLenientParsing, count, ref definition);
}
scanner.DeregisterCustomTokenizer(tokenizer);
}
builder.Dictionary = ParseTrailer(scanner, isLenientParsing);
return(builder.Build());
}
