internal static async Task WriteFinalFromBase64Urlsafe(
this Stream stream, Memory <byte> base64Memory,
CancellationToken cancelToken = default)
{
int base64Count = CommonBase64UrlSafe.RevertUrlSafeUtf8(base64Memory.Span,
out int base64PadCount);
int base64Length = base64Memory.Length + base64PadCount;
using (var base64FinalBuffer = bytesPool.Rent(base64Length))
{
Memory <byte> base64FinalMemory = base64FinalBuffer.Memory;
base64Memory.CopyTo(base64FinalMemory);
Memory <byte> base64PadMemory = base64FinalMemory.Slice(base64Memory.Length, base64PadCount);
base64PadMemory.Span.Fill(base64PadByte);
int bytesRequired = Base64.GetMaxDecodedFromUtf8Length(base64Count + base64PadCount);
int base64Consumed = await stream.WritePartialFromBase64(
base64FinalMemory.Slice(0, base64Length), bytesRequired,
isFinalBlock : true, cancelToken).ConfigureAwait(false);
if (base64Consumed < base64Length)
{
throw new InvalidOperationException("Base64 decode of final block did not consume all bytes");
}
}
}
internal static async Task <(int base64Remaining, int base64PadCount)> WritePartialFromBase64Urlsafe(
this Stream stream, Memory <byte> base64Memory,
CancellationToken cancelToken = default)
{
int base64Count = CommonBase64UrlSafe.RevertUrlSafeUtf8(base64Memory.Span,
out int base64PaddingRequired);
int bytesRequired = Base64.GetMaxDecodedFromUtf8Length(base64Count);
int base64Consumed = await stream.WritePartialFromBase64(base64Memory,
bytesRequired, isFinalBlock : false, cancelToken)
.ConfigureAwait(false);
Memory <byte> base64Remaining = base64Memory.Slice(base64Consumed);
base64Remaining.CopyTo(base64Memory);
return(base64Remaining.Length, base64PaddingRequired);
}