public async Task DeleteAvatarAsync(string userId)
{
AvatarInDb avatar = await _context.Avatars.FindAsync(userId);
if (avatar != null)
{
_context.Avatars.Remove(avatar);
await _context.SaveChangesAsync();
}
}
public async Task <Stream> GetAvatarStreamAsync(string userId)
{
AvatarInDb avatar = await _context.Avatars.FindAsync(userId);
if (avatar != null)
{
// if avatar exists extract from DB, store in memory and return
return(new MemoryStream(avatar.Avatar));
}
throw new NotFoundResponseException();
}
private async Task CreateOrUpdateAvatarAsync(AvatarInDb avatar)
{
AvatarInDb a = await _context.Avatars.FindAsync(avatar.UserId);
if (a != null)
{
a.Avatar = avatar.Avatar; // if avatar already exists then update it
}
else
{
await _context.Avatars.AddAsync(avatar); // if avatar doesn't already exist then create new record in DB
}
await _context.SaveChangesAsync();
}
public async Task SaveAvatarStreamAsync(string userId, Stream stream)
{
if (stream.Length > MAX_STREAM_LENGTH)
{
throw new ArgumentOutOfRangeException($"stream cannot contain more than {MAX_STREAM_LENGTH} bytes");
}
AvatarInDb avatar = new AvatarInDb
{
UserId = userId
};
int length = (int)stream.Length;
stream.Position = 0; // force reset position in stream before data coping
avatar.Avatar = new byte[length];
stream.Read(avatar.Avatar, 0, length);
await CreateOrUpdateAvatarAsync(avatar);
}