public async Task <IActionResult> Get(string name, int width, int height, string type, string watermark = "", string backgroundColor = "")
{
// Get the requested ETag
string requestETag = "";
if (Request.Headers.ContainsKey("If-None-Match"))
{
requestETag = Request.Headers["If-None-Match"].First();
}
//check distributed cache (Redis) if we had this exact request previously and we have it in cache!
string concatenatedKey = GetConcatenatedKey(name, width, height, type, watermark, backgroundColor);
FileContentResult fcr = null;
string key = GenerateHashKey(concatenatedKey);
byte[] imageBytes;
if (redisCacheService.HasValudBeenCached(key).Result)
{
//we have this in cache!
imageBytes = redisCacheService.GetCachedValueAsync(key).Result;
}
else
{
GetImageQuery query = GetImageQueryObject(name, width, height, type, watermark, backgroundColor);
//Using CQRS technique to send the query to the mediatR
var result = await Mediator.Send(query);
imageBytes = result.Data.ImageByteArray;
//Cache it now
redisCacheService.SetCacheValueAsync(key, imageBytes);
}
// Construct the new ETag
string responseETag = key;
// Return a 304 if the ETag of the current record matches the ETag in the "If-None-Match" HTTP header
if (Request.Headers.ContainsKey("If-None-Match") && responseETag == requestETag)
{
return(Ok(StatusCode((int)HttpStatusCode.NotModified)));
}
// Add the current ETag to the HTTP header
Response.Headers.Add("ETag", responseETag);
fcr = GetImageFile(type, imageBytes);
return(fcr);
}