private async Task <string> ProcessImages(
S3Event s3Event,
IImageScaler imageScaler,
ILogWriter <ImageResizeHandler> logger,
IPhotosService photoService)
{
logger.LogInformation($"{nameof(ProcessImages)}");
var s3Entity = s3Event.Records?[0].S3;
if (s3Entity == null)
{
logger.LogCritical($"{nameof(s3Entity)} is null");
return("NULL");
}
var urlDecodedKey = System.Web.HttpUtility.UrlDecode(s3Entity.Object.Key);
UserId userId = GetUserIdFromKey(urlDecodedKey);
PhotoId photoId = GetPhotoIdFromKey(urlDecodedKey);
try
{
logger.LogInformation($"{nameof(urlDecodedKey)} is '{urlDecodedKey}'");
await photoService.SetPhotoState(userId, photoId, PhotoState.ProcessingStarted);
// generate filenames to use for the scaled images
ImageKeys imageKeys = GetImageKeysWithoutExtension(urlDecodedKey);
IEnumerable <Size> imageSizes;
using (var s3InputObject = await S3Client.GetObjectAsync(s3Entity.Bucket.Name, urlDecodedKey))
using (var originalImageStream = new MemoryStream())
{
await ReadImageIntoStream(logger, originalImageStream, s3InputObject.ResponseStream);
imageSizes = await CreateScaledImages(imageScaler, logger, imageKeys, originalImageStream, GetTargetBucket());
}
logger.LogInformation($"Updating photo data, making it available.");
await UpdatePhotoData(photoService, photoId, imageSizes);
// finish with deleting the upload file
await DeleteOriginalSourceFile(logger, s3Entity, urlDecodedKey);
logger.LogInformation($"Done with {urlDecodedKey}");
return("OK");
}
catch (Exception ex)
{
logger.LogError(ex, $"Error when resizing {s3Entity.Object.Key} from bucket {s3Entity.Bucket.Name}:\n{ex.ToString()}");
// set photo state to ProcessingFailed
await photoService.SetPhotoState(userId, photoId, PhotoState.ProcessingFailed);
throw;
}
}
private Task <IEnumerable <Size> > CreateScaledImages(
IImageScaler imageScaler,
ILogWriter <ImageResizeHandler> logger,
ImageKeys imageKeys,
MemoryStream originalImageStream,
string targetBucket)
{
var imageSizes = new HashSet <Size>();
originalImageStream.Position = 0;
return(imageScaler.ScaleImageByWidths(
originalImageStream,
(scaledStream, size, extension) =>
{
imageSizes.Add(size);
string s3key = $"{imageKeys.ObjectKeys[size.Width]}.{extension}";
return StoreImageInTargetBucket(targetBucket, s3key, scaledStream, logger);
},
imageKeys.ObjectKeys.Keys));
}
