public async Task InvokeAsync(HttpContext httpContext)
{
var responseStream = httpContext.Response.Body;
var imageKey = BuildBmpFileName(httpContext.Request.Path);
//even if request doesn't contain image I'm still trying to grab the image from cache :(
var cachedImage = _cache.Get(imageKey);
if (cachedImage != null)
{
await cachedImage.CopyToAsync(responseStream);
return;
}
using (var stream = new MemoryStream())
{
httpContext.Response.Body = stream;
await _next(httpContext);
var isValidImageType = httpContext.Response.ContentType?.Contains(ValidImageType) ?? false;
if (isValidImageType)
{
_cache.Add(stream, imageKey);
}
stream.Seek(0, SeekOrigin.Begin);
await stream.CopyToAsync(responseStream);
}
}
public async Task <MemoryStream> RunAsync(string path)
{
MemoryStream memoryStream = new MemoryStream();
using (Stream stream = await httpClient.GetStreamAsync(path))
{
await stream.CopyToAsync(memoryStream);
}
memoryStream.Position = 0;
string checksum = ImageCacheUtils.GetChecksum(memoryStream);
Rectangle[] faceRects = imageCache.Get(path.ToString(), checksum);
if (faceRects == null)
{
faceRects = await faceDetection.Detect(path);
if (faceRects == null)
{
memoryStream.Position = 0;
return(memoryStream);
}
imageCache.Add(path.ToString(), checksum, faceRects);
}
if (faceRects.Length > 0)
{
memoryStream.Position = 0;
Bitmap bitmap = new Bitmap(memoryStream);
bitmap = imageEffect.Apply(bitmap, faceRects);
memoryStream.Position = 0;
bitmap.Save(memoryStream, ImageFormat.Png);
}
memoryStream.Position = 0;
return(memoryStream);
}
