private static int GetDispositionTypeLength(StringSegment input, int startIndex, out ContentDispositionHeaderValue?parsedValue)
{
Contract.Requires(startIndex >= 0);
parsedValue = null;
if (StringSegment.IsNullOrEmpty(input) || (startIndex >= input.Length))
{
return(0);
}
// Caller must remove leading whitespaces. If not, we'll return 0.
var dispositionTypeLength = GetDispositionTypeExpressionLength(input, startIndex, out var dispositionType);
if (dispositionTypeLength == 0)
{
return(0);
}
var current = startIndex + dispositionTypeLength;
current = current + HttpRuleParser.GetWhitespaceLength(input, current);
var contentDispositionHeader = new ContentDispositionHeaderValue();
contentDispositionHeader._dispositionType = dispositionType;
// If we're not done and we have a parameter delimiter, then we have a list of parameters.
if ((current < input.Length) && (input[current] == ';'))
{
current++; // skip delimiter.
int parameterLength = NameValueHeaderValue.GetNameValueListLength(input, current, ';',
contentDispositionHeader.Parameters);
parsedValue = contentDispositionHeader;
return(current + parameterLength - startIndex);
}
// We have a ContentDisposition header without parameters.
parsedValue = contentDispositionHeader;
return(current - startIndex);
}