private void RetrieveFileData(HttpContext context, string filePath, string container)
{
MediaFileModel resultModel = new MediaFileModel();
// only send request to imageprocessor if querystring exists; can exclude other parameters if needed
if (context.Request.RawUrl.Contains("?"))
{
resultModel = MediaHelper.GetMediaFile(filePath, container, context.Request.RawUrl);
}
else
{
resultModel = MediaHelper.GetMediaFile(filePath, container);
}
if (resultModel.RedirectToAzureStorage)
{
context.Response.Redirect(filePath.Replace($"/{container}", $"{ConfigurationManager.AppSettings["BlobStorage"]}/{container}"), true);
}
var myTimeSpan = new TimeSpan(7, 0, 0, 0);
context.Response.Cache.SetCacheability(HttpCacheability.Public);
context.Response.Cache.SetValidUntilExpires(true);
context.Response.Cache.SetMaxAge(myTimeSpan);
context.Response.Cache.SetLastModified(resultModel.LastModifiedDate);
context.Response.Cache.SetETag(resultModel.ETag.Replace("\\\"", ""));
context.Response.AddHeader("Content-MD5", resultModel.ContentMd5);
context.Response.ContentType = resultModel.ContentType;
// replicate properties returned by blob storage
context.Response.AddHeader("Server", "Windows-Azure-Blob/1.0 Microsoft-HTTPAPI/2.0");
context.Response.AddHeader("x-ms-request-id", Guid.NewGuid().ToString());
context.Response.AddHeader("x-ms-version", "2009-09-19");
context.Response.AddHeader("x-ms-lease-status", "unlocked");
context.Response.AddHeader("x-ms-blob-type", "BlockBlob");
context.Response.OutputStream.Write(resultModel.ImageData, 0, resultModel.ImageData.Length);
context.Response.AddHeader("Content-Length", resultModel.ImageData.Length.ToString());
context.Response.Flush();
context.Response.End();
}
/// <summary>
/// Retrieve media content directly from blob storage.
/// </summary>
/// <param name="filePath">Relative file path</param>
/// <param name="container">Container to retrieve media file from</param>
/// <returns>Media file using the MediaFileModel</returns>
public static MediaFileModel GetMediaFile(string filePath, string container)
{
var myModel = new MediaFileModel();
var storageAccount = Account;
// validate the container has been defined
if (string.IsNullOrWhiteSpace(container))
throw new ArgumentNullException("Container is missing; this is required.");
var blobContainer = storageAccount.CreateCloudBlobClient().GetContainerReference(container);
// validate the filepath isn't empty
if (string.IsNullOrWhiteSpace(filePath))
throw new ArgumentNullException("File path is missing; this is required.");
var mediaFile = blobContainer.GetBlockBlobReference(filePath.ToLower().Replace($"/{container}/", string.Empty));
// validate the file exists; if not, return 404
if (mediaFile == null || !mediaFile.Exists())
{
myModel.RedirectToAzureStorage = true;
return myModel;
}
var myStream = new MemoryStream();
mediaFile.DownloadToStream(myStream);
myModel.ImageData = myStream.ToArray();
myModel.ContentType = mediaFile.Properties.ContentType;
myModel.RedirectToAzureStorage = false;
myModel.LastModifiedDate = mediaFile.Properties.LastModified?.DateTime ?? DateTime.Now;
myModel.ETag = mediaFile.Properties.ETag;
myModel.ContentMd5 = mediaFile.Properties.ContentMD5;
return myModel;
}
/// <summary>
/// Retrieve media file from Azure Storage and additionally call image processor to retrieve the dynamic image based on the raw url.
/// </summary>
/// <param name="filePath">The relative filepath to the file.</param>
/// <param name="container">Container to retrieve media file from.</param>
/// <param name="rawUrl">The url to the file including the query string.</param>
/// <returns>Media file using the MediaFileModel</returns>
public static MediaFileModel GetMediaFile(string filePath, string container, string rawUrl)
{
var myModel = new MediaFileModel();
myModel = GetMediaFile(filePath, container);
// if RedirectToAzureStorage was set, we couldn't retrieve the media file, so doubtful the remote request will work either.
if (myModel.RedirectToAzureStorage) return myModel;
// call remote.axd to the defined Azure CDN and pass in the blob storage location.
var webc = new WebClient();
myModel.ImageData =
webc.DownloadData(
$"{ConfigurationManager.AppSettings["AzureCDN"]}/remote.axd/{ConfigurationManager.AppSettings["BlobStorageRequest"]}{rawUrl}");
return myModel;
}
