public static Base64ParserResult Parse(ReadOnlySpan <char> data, string fileName)
{
var commaPos = data.IndexOf(',');
if (commaPos == -1)
{
throw new ArgumentException($"Invalid data payload for {fileName}");
}
var headerEnumerator = data.Slice(0, commaPos).ToLower().Split(';');
headerEnumerator.MoveNext();
var ctPartEnumerator = headerEnumerator.Current.Split(':');
var ctPartLength = ctPartEnumerator.Last(out var ctPart);
var contentType = ctPartLength > 1 ? ctPart : string.Empty;
var isBase64 = false;
var charsetToken = "charset".AsSpan();
var base64Token = "base64".AsSpan();
if (headerEnumerator.MoveNext())
{
if (headerEnumerator.Current.StartsWith(charsetToken))
{
var charsetPart = headerEnumerator.Current.Split('=');
var charsetPartLen = charsetPart.Last(out _); //TODO Work with charset
if (charsetPartLen == 2)
{
//TODO Charset now not using
}
else
{
throw new ArgumentException($"Invalid charset description for {fileName}");
}
}
else if (headerEnumerator.Current.SequenceEqual(base64Token))
{
isBase64 = true;
}
if (!isBase64 && headerEnumerator.MoveNext())
{
isBase64 = headerEnumerator.Current.SequenceEqual(base64Token);
}
}
if (!isBase64)
{
throw new ArgumentException($"Invalid encoding type for {fileName}");
}
return(new Base64ParserResult(contentType
, bytes: Base64ConvertHelper.ConvertToBytes(data.Slice(commaPos + 1))));
}
public static IEnumerable <Upload> AsFileDescriptors(this IEnumerable <Base64FilePayload> files, IContentTypeTestUtility contentTypeTestUtility)
{
var number = 0U;
foreach (var rawFile in files)
{
string contentType;
var data = rawFile.RawData.AsSpan();
ReadOnlyMemory <byte> byteArr;
if (data.StartsWith(Base64FilePayload.DataToken.AsSpan(), StringComparison.InvariantCultureIgnoreCase))
{
(contentType, byteArr) = Base64Parser.Parse(data, rawFile.Name);
}
else
{
byteArr = Base64ConvertHelper.ConvertToBytes(data);
contentType = string.Empty;
}
if (string.IsNullOrEmpty(contentType))
{
contentType = contentTypeTestUtility.DetectContentType(byteArr.Slice(0, 4).Span);
}
if (contentTypeTestUtility.IsAllowed(contentType))
{
yield return(new Upload(
id: Guid.NewGuid(),
previewId: Guid.NewGuid(),
num: number++,
name: rawFile.Name,
contentType: contentType,
streamAdapter: new ByteaStreamAdapter(byteArr)));
}
}
}
