IO optimalizations, deployment, security
Dominik Pinter, dominikp@kentico.com


Agenda
•CMS.IO:
•Optimalization
•Temporary files
•Object locking
•File access
•Debug
•Deployment:
•Compilation, debugging
•On-premise vs. Off-premise
•Security:
•Web security
•C# code security

CMS.IO optimalization - caching
•public override bool Exists(string path)
•{
•             return Provider.GetFileFromPath(path) != null;
•}
•
•
•
•public FileClass GetFile(string id)
•{
•            try
•            {
•                return Service.Files.Get(id).Fetch();
•            }
•            catch (Exception)
•            {
•                return null;
•            }
•}

CMS.IO - caching
•What?
–Metadata
–File contents
•How?
–RequestStockHelper
–Local file system
•Techniques
–E-tag
–Download only what is really needed

CMS.IO - caching
•public bool Exists()
•{
•            if (RequestStockHelper.Contains(Key + "|Exists"))
•            {
•                return ValidationHelper.GetBoolean(RequestStockHelper.GetItem(Key + "|Exists"),
false);
•            }
•
•            GetObjectMetadataRequest request = new GetObjectMetadataRequest();
•            request.BucketName = BucketName;
•            request.Key = Key;
•
•            try
•            {
•                GetObjectMetadataResponse response = S3Client.GetObjectMetadata(request);
•                response.Dispose();
•
•                RequestStockHelper.Add(Key + "|Exists", true);
•                RequestStockHelper.Add(Key + "|Length", response.ContentLength);
•                RequestStockHelper.Add(Key + "|FetchMetadata", true);
•
•                return true;
•             }
• …

CMS.IO - caching
•public CMS.IO.Stream GetObjectContent(IS3ObjectInfo obj)
•{
•                     // First try to get data from cache
• string cachePath = PathHelper.CachePath + GetPathFromObjectKey(obj.Key, false);
• string eTagFilename = cachePath + ".etag";
•
• if (CMS.IO.File.Exists(cachePath))
• {
• string eTag = System.IO.File.ReadAllText(eTagFilename).Trim();
• if (eTag == obj.ETag)
• {
• // Return cached object
•                                           }
• }
•
• // Download object
• // Save it to cache
•}

CMS.IO optimalization – temporary files
•private System.IO.FileStream _innerStream;
•
•public override void Write(byte[] buffer, int offset, int count)
•{
• _innerStream.Write(buffer, offset, count);
•}
•
•public override void Dispose()
•{
• _innerStream.Close();
•
• if (fileAccess != FileAccess.Read && fileMode != FileMode.Open)
• {
• _fileService.FileWriteContent(_validPath.ObjectName, _validPath.Parent,
System.IO.File.ReadAllText(_validPath.ObjectName));
• }
•}

CMS.IO - locking
•public void Lock()
•{
•      if (Provider.ObjectExists(this))
•      {
•             SetMetadata(S3ObjectInfoProvider.LOCK,      "True", true, false);
•        }
•}
•
•
•public void UnLock()
•{
•       if (Provider.ObjectExists(this))
•       {
•              SetMetadata(S3ObjectInfoProvider.LOCK, "False", true, false);
•        }
•}
•
•
•
•
•
•
•
•
•
•public void PutTextToObject(IS3ObjectInfo obj, string content)
•{
• if (!obj.IsLocked)
• {
• obj.Lock();
•
• // Do action
•
• obj.UnLock();
• RemoveRequestCache(obj.Key);
• }
•}
File
Process 1
Process 2

CMS.IO – public access
•Komentář z jednoho z projektů v metodě GetFileUrl:
•
•/* opsano z Amazon solution - nemate nekdo implementaci techto metod abych pochopil co delaj?
podle jejich jmen to moc poznat nejde (i kdyz by melo)
• string url = AmazonHelper.GetDownloadPath(relative);
• string hash = ValidationHelper.GetHashString(URLHelper.GetQuery(url), false);
• url = URLHelper.AddParameterToUrl(url, "hash", hash);
•
• return URLHelper.ResolveUrl(url);
•*/

CMS.IO – public access
•1. Implement file access:  request.CannedACL = S3CannedACL.PublicRead;
•
•2. Implement method for resolving URLs:
•
•       public override string GetFileUrl(string path, string siteName)
•        {
•            string objKey = PathHelper.GetObjectKeyFromPath(path);
•            if (ExistsInS3Storage(path))
•            {
•                if (AmazonHelper.PublicAccess)
•                {
• return String.Format("{0}/{1}", AmazonHelper.EndPoint, objKey).ToLowerCSafe();
•                }
•
•                string relative = "~\\" + objKey.Replace('/', '\\');
•
•                string url = AmazonHelper.GetDownloadPath(relative);
•                string hash = ValidationHelper.GetHashString(URLHelper.GetQuery(url), false);
•                url = URLHelper.AddParameterToUrl(url, "hash", hash);
•                return URLHelper.ResolveUrl(url);
•            }
•
•            return null;
•        }

CMS.IO - debug
•Helps you with optimalizations
–1 storage operation per 1 request
–Content is downloaded only once
–
•CMSSiteManager->Administration->System->Debug->IO
•Live site
•
•using CMS.IO
–Directory.LogDirectoryOperation()
–File.LogFileOperation()
–
• IOOperationType.General
–Use prefixes to identify storage operations

Deployment – On-premise vs. Off-premise
•On-premise = standard server
–webhosting
•Off-premise = cloud
–IaaS vs. PaaS vs. SaaS
–Multi servers environment
–Shared storage
–Content delivery network
•

Security: web security
•Golden rule: sanitize users input!
•
•GetXXFile.aspx:
•
•protected void Page_Load(object sender, EventArgs e)
•{
•        string hash = QueryHelper.GetString("hash", string.Empty);
•        string path = QueryHelper.GetString("path", string.Empty);
•        if (ValidationHelper.ValidateHash("?path=" + path, hash, false))
•        {
•        }
•}

Q&A
•?


•Thank you
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•http://www.kentico.com
•http://devnet.kentico.com
•dominikp@kentico.com
•
C:\@@Kentico-Works\Images\Logo_3D_TagCMS.jpg