protected Task CreateItemGetResponse()

in src/WebJobs.Script.WebHost/Management/VirtualFileSystem.cs [259:333]
59 lines of code
10 McCabe index (conditional complexity)

        protected Task<HttpResponseMessage> CreateItemGetResponse(HttpRequest request, FileSystemInfoBase info, string localFilePath)
        {
            // Get current etag
            var currentEtag = CreateEntityTag(info);
            var lastModified = info.LastWriteTimeUtc;

            // Check whether we have a range request (taking If-Range condition into account)
            bool isRangeRequest = IsRangeRequest(request, currentEtag);

            // Check whether we have a conditional If-None-Match request
            // Unless it is a range request (see RFC2616 sec 14.35.2 Range Retrieval Requests)
            if (!isRangeRequest && IsIfNoneMatchRequest(request, currentEtag.ToSystemETag()))
            {
                var notModifiedResponse = CreateResponse(HttpStatusCode.NotModified);
                notModifiedResponse.SetEntityTagHeader(currentEtag.ToSystemETag(), lastModified);
                return Task.FromResult(notModifiedResponse);
            }

            // Generate file response
            Stream fileStream = null;
            try
            {
                fileStream = GetFileReadStream(localFilePath);
                var mediaType = MediaTypeMap.GetMediaType(info.Extension);
                var successFileResponse = CreateResponse(isRangeRequest ? HttpStatusCode.PartialContent : HttpStatusCode.OK);

                if (isRangeRequest)
                {
                    var typedHeaders = request.GetTypedHeaders();
                    var rangeHeader = new RangeHeaderValue
                    {
                        Unit = typedHeaders.Range.Unit.Value
                    };

                    foreach (var range in typedHeaders.Range.Ranges)
                    {
                        rangeHeader.Ranges.Add(new RangeItemHeaderValue(range.From, range.To));
                    }

                    successFileResponse.Content = new ByteRangeStreamContent(fileStream, rangeHeader, mediaType, BufferSize);
                }
                else
                {
                    successFileResponse.Content = new StreamContent(fileStream, BufferSize);
                    successFileResponse.Content.Headers.ContentType = mediaType;
                }

                // Set etag for the file
                successFileResponse.SetEntityTagHeader(currentEtag.ToSystemETag(), lastModified);
                return Task.FromResult(successFileResponse);
            }
            catch (InvalidByteRangeException invalidByteRangeException)
            {
                // The range request had no overlap with the current extend of the resource so generate a 416 (Requested Range Not Satisfiable)
                // including a Content-Range header with the current size.
                _logger.LogWarning(invalidByteRangeException.Message);
                var invalidByteRangeResponse = CreateResponse(HttpStatusCode.RequestedRangeNotSatisfiable, invalidByteRangeException);
                if (fileStream != null)
                {
                    fileStream.Close();
                }
                return Task.FromResult(invalidByteRangeResponse);
            }
            catch (Exception ex)
            {
                // Could not read the file
                _logger.LogError(ex, "Unable to read file: " + ex.Message);
                var errorResponse = CreateResponse(HttpStatusCode.NotFound, ex);
                if (fileStream != null)
                {
                    fileStream.Close();
                }
                return Task.FromResult(errorResponse);
            }
        }