Exemplo n.º 1
0
        public async Task <AuxiliaryFileResult <DownloadData> > ReadLatestIndexedAsync(
            IAccessCondition accessCondition,
            StringCache stringCache)
        {
            var stopwatch     = Stopwatch.StartNew();
            var blobName      = GetLatestIndexedBlobName();
            var blobReference = Container.GetBlobReference(blobName);

            _logger.LogInformation("Reading the latest indexed downloads from {BlobName}.", blobName);

            bool modified;
            var  downloads = new DownloadData();
            AuxiliaryFileMetadata metadata;

            try
            {
                using (var stream = await blobReference.OpenReadAsync(accessCondition))
                {
                    ReadStream(
                        stream,
                        (id, version, downloadCount) =>
                    {
                        id      = stringCache.Dedupe(id);
                        version = stringCache.Dedupe(version);
                        downloads.SetDownloadCount(id, version, downloadCount);
                    });
                    modified = true;
                    metadata = new AuxiliaryFileMetadata(
                        lastModified: new DateTimeOffset(blobReference.LastModifiedUtc, TimeSpan.Zero),
                        loadDuration: stopwatch.Elapsed,
                        fileSize: blobReference.Properties.Length,
                        etag: blobReference.ETag);
                }
            }
            catch (StorageException ex) when(ex.RequestInformation.HttpStatusCode == (int)HttpStatusCode.NotModified)
            {
                _logger.LogInformation("The blob {BlobName} has not changed.", blobName);
                modified  = false;
                downloads = null;
                metadata  = null;
            }

            stopwatch.Stop();
            _telemetryService.TrackReadLatestIndexedDownloads(downloads?.Count, modified, stopwatch.Elapsed);

            return(new AuxiliaryFileResult <DownloadData>(
                       modified,
                       downloads,
                       metadata));
        }