private static async Task ProcessImageProcessingMessageAsync(ImageMessage message)
{
var stopwatch = new Stopwatch();
stopwatch.Start();
// keep track of the gallery id so we can work on the gallery after the message batch is processed
lock (_galleryId)
_galleryId = new DatabaseId(message.GalleryId, message.GalleryCategoryId);
// retrieve Image object and bytes
var image = await GetImageAsync(message.ImageId, message.GalleryId);
var imageBytes = await GetImageBytesAsync(image);
// create array of file specs to iterate over
var specs = new List <FileSpec> {
FileSpec.Spec3840, FileSpec.Spec2560, FileSpec.Spec1920, FileSpec.Spec800, FileSpec.SpecLowRes
};
// resize original image file to smaller versions in parallel
//var parallelTasks = specs.Select(spec => ProcessImageAsync(image, imageBytes, spec)).ToList();
//await Task.WhenAll(parallelTasks);
//foreach (var spec in specs)
// await ProcessImageAsync(image, imageBytes, spec);
// This approach is the fastest of the three methods here. I have no idea why.
// 20MB image resized five times (each spec)
// Task.WhenAll: 11785ms average
// Foreach: 8540ms average
// Parallel.Foreach with GetAwaiter/GetResult: 7887ms average
Parallel.ForEach(specs, spec =>
{
ProcessImageAsync(image, imageBytes, spec).GetAwaiter().GetResult();
});
MetadataUtils.ParseAndAssignImageMetadata(image, imageBytes, message.OverwriteImageProperties, _log);
await UpdateImageAsync(image);
// pre-cache the image so it renders instantly for visitors
PreCacheImage(image);
// when uploading images, they don't have a position set, so if one is set when we process it here
// then it's likely it's an existing Image that's having it's image file replaced. If so and the position
// is zero then we want to make sure we update the gallery thumbnail to use the new image files.
if (image.Position == 0)
{
_log.Debug("LB.PhotoGalleries.Worker.Program.ProcessImageProcessingMessageAsync() - Image position = 0, need to update gallery thumbnail...");
var gallery = await GetGalleryAsync(image.GalleryCategoryId, image.GalleryId);
await UpdateGalleryThumbnailAsync(gallery, image.Files);
}
stopwatch.Stop();
_log.Information($"LB.PhotoGalleries.Worker.Program.ProcessImageProcessingMessageAsync() - Processed {image.Id} in {stopwatch.ElapsedMilliseconds}ms");
}
private static async Task HandleMessageAsync(QueueMessage message)
{
// decode the message
var components = Utilities.Base64Decode(message.MessageText).Split(':');
ImageMessage imageMessage = null;
try
{
imageMessage = new ImageMessage
{
Operation = Enum.Parse <WorkerOperation>(components[0], true),
ImageId = components[1],
GalleryId = components[2],
GalleryCategoryId = components[3],
OverwriteImageProperties = bool.Parse(components[4])
};
}
catch (Exception e)
{
Log.Error($"LB.PhotoGalleries.Worker.Program.HandleMessageAsync() - Failed to decode message : '{message.MessageText}'", e);
}
try
{
if (imageMessage != null)
{
if (imageMessage.Operation == WorkerOperation.Process)
{
await ProcessImageProcessingMessageAsync(imageMessage);
}
else
{
await ReprocessImageMetadataAsync(imageMessage);
}
}
}
catch (ImageNotFoundException e)
{
_log.Error(e, "Image not found, deleting message.");
}
// as the message was processed successfully, we can delete the message from the queue
await _queueClient.DeleteMessageAsync(message.MessageId, message.PopReceipt);
}
/// <summary>
/// Causes an image to have it's metadata re-examined and updates applied to the image.
/// Useful for when we make improvements to metadata parsing.
/// </summary>
private static async Task ReprocessImageMetadataAsync(ImageMessage message)
{
// retrieve the image
// download the bytes
// parse the metadata
// update the image properties
// persist image changes to db
_log.Verbose("LB.PhotoGalleries.Worker.Program.ReprocessImageMetadataAsync()");
var image = await GetImageAsync(message.ImageId, message.GalleryId);
var imageBytes = await GetImageBytesAsync(image);
MetadataUtils.ParseAndAssignImageMetadata(image, imageBytes, message.OverwriteImageProperties);
await UpdateImageAsync(image);
_log.Information($"LB.PhotoGalleries.Worker.Program.ReprocessImageMetadataAsync() - Reprocessed metadata on image {image.Id}");
}
