alias method - Page 288

Updating resources in SharpDX - why can I not map a dynamic texture?

- by sebf

I am trying to map a Texture2D resource in DirectX11 via SharpDX. The resource is declared as a ShaderResource, with Default usage and the 'Write' CPU flag specified. My call however fails with a generic exception from SharpDX: _Parent.Context.MapSubresource(_Resource, 0, SharpDX.Direct3D11.MapMode.Write, SharpDX.Direct3D11.MapFlags.None, out stream); I see from this question that it is supported. The MSDN docs and this other question hint that instead of using Context.MapSubresource() I should be using Texture2D.Map(), however, the DirectX11 Texture2D class does not define Map() (though it does for the DX10 equivalent). If I call the above with MapMode.WriteDiscard, the call succeeds but in this case the previous content of the texture is lost, which is no good when I only want to update a section of it. Has the Map() method been removed in DirectX11 or am I looking in the wrong place? Is the MapSubresource() method unsuitable or am I using it wrong?

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ASP.NET MVC Paging/Sorting/Filtering using the MVCContrib Grid and Pager

- by rajbk

This post walks you through creating a UI for paging, sorting and filtering a list of data items. It makes use of the excellent MVCContrib Grid and Pager Html UI helpers. A sample project is attached at the bottom. Our UI will eventually look like this. The application will make use of the Northwind database. The top portion of the page has a filter area region. The filter region is enclosed in a form tag. The select lists are wired up with jQuery to auto post back the form. The page has a pager region at the top and bottom of the product list. The product list has a link to display more details about a given product. The column headings are clickable for sorting and an icon shows the sort direction. Strongly Typed View Models The views are written to expect strongly typed objects. We suffix these strongly typed objects with ViewModel since they are designed specifically for passing data down to the view. The following listing shows the ProductViewModel. This class will be used to hold information about a Product. We use attributes to specify if the property should be hidden and what its heading in the table should be. This metadata will be used by the MvcContrib Grid to render the table. Some of the properties are hidden from the UI ([ScaffoldColumn(false)) but are needed because we will be using those for filtering when writing our LINQ query. public ActionResult Index( string productName, int? supplierID, int? categoryID, GridSortOptions gridSortOptions, int? page) { var productList = productRepository.GetProductsProjected(); // Set default sort column if (string.IsNullOrWhiteSpace(gridSortOptions.Column)) { gridSortOptions.Column = "ProductID"; } // Filter on SupplierID if (supplierID.HasValue) { productList = productList.Where(a => a.SupplierID == supplierID); } // Filter on CategoryID if (categoryID.HasValue) { productList = productList.Where(a => a.CategoryID == categoryID); } // Filter on ProductName if (!string.IsNullOrWhiteSpace(productName)) { productList = productList.Where(a => a.ProductName.Contains(productName)); } // Create all filter data and set current values if any // These values will be used to set the state of the select list and textbox // by sending it back to the view. var productFilterViewModel = new ProductFilterViewModel(); productFilterViewModel.SelectedCategoryID = categoryID ?? -1; productFilterViewModel.SelectedSupplierID = supplierID ?? -1; productFilterViewModel.Fill(); // Order and page the product list var productPagedList = productList .OrderBy(gridSortOptions.Column, gridSortOptions.Direction) .AsPagination(page ?? 1, 10); var productListContainer = new ProductListContainerViewModel { ProductPagedList = productPagedList, ProductFilterViewModel = productFilterViewModel, GridSortOptions = gridSortOptions }; return View(productListContainer); } The following diagram shows the rest of the key ViewModels in our design. We have a container class called ProductListContainerViewModel which has nested classes. The ProductPagedList is of type IPagination<ProductViewModel>. The MvcContrib expects the IPagination<T> interface to determine the page number and page size of the collection we are working with. You convert any IEnumerable<T> into an IPagination<T> by calling the AsPagination extension method in the MvcContrib library. It also creates a paged set of type ProductViewModel. The ProductFilterViewModel class will hold information about the different select lists and the ProductName being searched on. It will also hold state of any previously selected item in the lists and the previous search criteria (you will recall that this type of state information was stored in Viewstate when working with WebForms). With MVC there is no state storage and so all state has to be fetched and passed back to the view. The GridSortOptions is a type defined in the MvcContrib library and is used by the Grid to determine the current column being sorted on and the current sort direction. The following shows the view and partial views used to render our UI. The Index view expects a type ProductListContainerViewModel which we described earlier. <%Html.RenderPartial("SearchFilters", Model.ProductFilterViewModel); %> <% Html.RenderPartial("Pager", Model.ProductPagedList); %> <% Html.RenderPartial("SearchResults", Model); %> <% Html.RenderPartial("Pager", Model.ProductPagedList); %> The View contains a partial view “SearchFilters” and passes it the ProductViewFilterContainer. The SearchFilter uses this Model to render all the search lists and textbox. The partial view “Pager” uses the ProductPageList which implements the interface IPagination. The “Pager” view contains the MvcContrib Pager helper used to render the paging information. This view is repeated twice since we want the pager UI to be available at the top and bottom of the product list. The Pager partial view is located in the Shared directory so that it can be reused across Views. The partial view “SearchResults” uses the ProductListContainer model. This partial view contains the MvcContrib Grid which needs both the ProdctPagedList and GridSortOptions to render itself. The Controller Action An example of a request like this: /Products?productName=test&supplierId=29&categoryId=4. The application receives this GET request and maps it to the Index method of the ProductController. Within the action we create an IQueryable<ProductViewModel> by calling the GetProductsProjected() method. /// <summary> /// This method takes in a filter list, paging/sort options and applies /// them to an IQueryable of type ProductViewModel /// </summary> /// <returns> /// The return object is a container that holds the sorted/paged list, /// state for the fiters and state about the current sorted column /// </returns> public ActionResult Index( string productName, int? supplierID, int? categoryID, GridSortOptions gridSortOptions, int? page) { var productList = productRepository.GetProductsProjected(); // Set default sort column if (string.IsNullOrWhiteSpace(gridSortOptions.Column)) { gridSortOptions.Column = "ProductID"; } // Filter on SupplierID if (supplierID.HasValue) { productList.Where(a => a.SupplierID == supplierID); } // Filter on CategoryID if (categoryID.HasValue) { productList = productList.Where(a => a.CategoryID == categoryID); } // Filter on ProductName if (!string.IsNullOrWhiteSpace(productName)) { productList = productList.Where(a => a.ProductName.Contains(productName)); } // Create all filter data and set current values if any // These values will be used to set the state of the select list and textbox // by sending it back to the view. var productFilterViewModel = new ProductFilterViewModel(); productFilterViewModel.SelectedCategoryID = categoryID ?? -1; productFilterViewModel.SelectedSupplierID = supplierID ?? -1; productFilterViewModel.Fill(); // Order and page the product list var productPagedList = productList .OrderBy(gridSortOptions.Column, gridSortOptions.Direction) .AsPagination(page ?? 1, 10); var productListContainer = new ProductListContainerViewModel { ProductPagedList = productPagedList, ProductFilterViewModel = productFilterViewModel, GridSortOptions = gridSortOptions }; return View(productListContainer); } The supplier, category and productname filters are applied to this IQueryable if any are present in the request. The ProductPagedList class is created by applying a sort order and calling the AsPagination method. Finally the ProductListContainerViewModel class is created and returned to the view. You have seen how to use strongly typed views with the MvcContrib Grid and Pager to render a clean lightweight UI with strongly typed views. You also saw how to use partial views to get data from the strongly typed model passed to it from the parent view. The code also shows you how to use jQuery to auto post back. The sample is attached below. Don’t forget to change your connection string to point to the server containing the Northwind database. NorthwindSales_MvcContrib.zip My name is Kobayashi. I work for Keyser Soze.

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SQL SERVER – Fix : Error : 8501 MSDTC on server is unavailable. Changed database context to publishe

- by pinaldave

During configuring replication on one of the server, I received following error. This is very common error and the solution of the same is even simpler. MSDTC on server is unavailable. Changed database context to publisherdatabase. (Microsoft SQL Server, Error: 8501) Solution: Enable “Distributed Transaction Coordinator” in SQL Server. Method 1: Click on Start–>Control Panel->Administrative Tools->Services Select the service “Distributed Transaction Coordinator” Right on the service and choose “Start” Method 2: Type services.msc in the run command box Select “Services” manager; Hit Enter Select the service “Distributed Transaction Coordinator” Right on the service and choose “Start” Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Error Messages, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Replication

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How to remove CRUD operations from Entity Class

- by GlutVonSmark

Trying to get my head around removing dataStore access from my entity classes. Lets say I have an AccountsGroup entity class. I put the all DBAccess into AccountsGroupRepository class. Now should I have a DeleteFromDB method in the AccountsGroup class, that will call the repository? Public Sub DeleteFromDB dim repository as new AccountsGroupRepository(me) repository.DelteFromDB End Sub Or should I just always use repositry whenever I need to delete an entity, and not have the CRUD methods in the entity class? What happens when there is some business logic validation that needs to be done before the delete can proceed. For example if AccountsGroup still has some Accounts in it the delete method should throw an exception. Where do I put that?

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Parallelism in .NET – Part 3, Imperative Data Parallelism: Early Termination

- by Reed

Although simple data parallelism allows us to easily parallelize many of our iteration statements, there are cases that it does not handle well. In my previous discussion, I focused on data parallelism with no shared state, and where every element is being processed exactly the same. Unfortunately, there are many common cases where this does not happen. If we are dealing with a loop that requires early termination, extra care is required when parallelizing. Often, while processing in a loop, once a certain condition is met, it is no longer necessary to continue processing. This may be a matter of finding a specific element within the collection, or reaching some error case. The important distinction here is that, it is often impossible to know until runtime, what set of elements needs to be processed. In my initial discussion of data parallelism, I mentioned that this technique is a candidate when you can decompose the problem based on the data involved, and you wish to apply a single operation concurrently on all of the elements of a collection. This covers many of the potential cases, but sometimes, after processing some of the elements, we need to stop processing. As an example, lets go back to our previous Parallel.ForEach example with contacting a customer. However, this time, we’ll change the requirements slightly. In this case, we’ll add an extra condition – if the store is unable to email the customer, we will exit gracefully. The thinking here, of course, is that if the store is currently unable to email, the next time this operation runs, it will handle the same situation, so we can just skip our processing entirely. The original, serial case, with this extra condition, might look something like the following: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) break; customer.LastEmailContact = DateTime.Now; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re processing our loop, but at any point, if we fail to send our email successfully, we just abandon this process, and assume that it will get handled correctly the next time our routine is run. If we try to parallelize this using Parallel.ForEach, as we did previously, we’ll run into an error almost immediately: the break statement we’re using is only valid when enclosed within an iteration statement, such as foreach. When we switch to Parallel.ForEach, we’re no longer within an iteration statement – we’re a delegate running in a method. This needs to be handled slightly differently when parallelized. Instead of using the break statement, we need to utilize a new class in the Task Parallel Library: ParallelLoopState. The ParallelLoopState class is intended to allow concurrently running loop bodies a way to interact with each other, and provides us with a way to break out of a loop. In order to use this, we will use a different overload of Parallel.ForEach which takes an IEnumerable<T> and an Action<T, ParallelLoopState> instead of an Action<T>. Using this, we can parallelize the above operation by doing: Parallel.ForEach(customers, (customer, parallelLoopState) => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) parallelLoopState.Break(); else customer.LastEmailContact = DateTime.Now; } }); There are a couple of important points here. First, we didn’t actually instantiate the ParallelLoopState instance. It was provided directly to us via the Parallel class. All we needed to do was change our lambda expression to reflect that we want to use the loop state, and the Parallel class creates an instance for our use. We also needed to change our logic slightly when we call Break(). Since Break() doesn’t stop the program flow within our block, we needed to add an else case to only set the property in customer when we succeeded. This same technique can be used to break out of a Parallel.For loop. That being said, there is a huge difference between using ParallelLoopState to cause early termination and to use break in a standard iteration statement. When dealing with a loop serially, break will immediately terminate the processing within the closest enclosing loop statement. Calling ParallelLoopState.Break(), however, has a very different behavior. The issue is that, now, we’re no longer processing one element at a time. If we break in one of our threads, there are other threads that will likely still be executing. This leads to an important observation about termination of parallel code: Early termination in parallel routines is not immediate. Code will continue to run after you request a termination. This may seem problematic at first, but it is something you just need to keep in mind while designing your routine. ParallelLoopState.Break() should be thought of as a request. We are telling the runtime that no elements that were in the collection past the element we’re currently processing need to be processed, and leaving it up to the runtime to decide how to handle this as gracefully as possible. Although this may seem problematic at first, it is a good thing. If the runtime tried to immediately stop processing, many of our elements would be partially processed. It would be like putting a return statement in a random location throughout our loop body – which could have horrific consequences to our code’s maintainability. In order to understand and effectively write parallel routines, we, as developers, need a subtle, but profound shift in our thinking. We can no longer think in terms of sequential processes, but rather need to think in terms of requests to the system that may be handled differently than we’d first expect. This is more natural to developers who have dealt with asynchronous models previously, but is an important distinction when moving to concurrent programming models. As an example, I’ll discuss the Break() method. ParallelLoopState.Break() functions in a way that may be unexpected at first. When you call Break() from a loop body, the runtime will continue to process all elements of the collection that were found prior to the element that was being processed when the Break() method was called. This is done to keep the behavior of the Break() method as close to the behavior of the break statement as possible. We can see the behavior in this simple code: var collection = Enumerable.Range(0, 20); var pResult = Parallel.ForEach(collection, (element, state) => { if (element > 10) { Console.WriteLine("Breaking on {0}", element); state.Break(); } Console.WriteLine(element); }); If we run this, we get a result that may seem unexpected at first: 0 2 1 5 6 3 4 10 Breaking on 11 11 Breaking on 12 12 9 Breaking on 13 13 7 8 Breaking on 15 15 What is occurring here is that we loop until we find the first element where the element is greater than 10. In this case, this was found, the first time, when one of our threads reached element 11. It requested that the loop stop by calling Break() at this point. However, the loop continued processing until all of the elements less than 11 were completed, then terminated. This means that it will guarantee that elements 9, 7, and 8 are completed before it stops processing. You can see our other threads that were running each tried to break as well, but since Break() was called on the element with a value of 11, it decides which elements (0-10) must be processed. If this behavior is not desirable, there is another option. Instead of calling ParallelLoopState.Break(), you can call ParallelLoopState.Stop(). The Stop() method requests that the runtime terminate as soon as possible , without guaranteeing that any other elements are processed. Stop() will not stop the processing within an element, so elements already being processed will continue to be processed. It will prevent new elements, even ones found earlier in the collection, from being processed. Also, when Stop() is called, the ParallelLoopState’s IsStopped property will return true. This lets longer running processes poll for this value, and return after performing any necessary cleanup. The basic rule of thumb for choosing between Break() and Stop() is the following. Use ParallelLoopState.Stop() when possible, since it terminates more quickly. This is particularly useful in situations where you are searching for an element or a condition in the collection. Once you’ve found it, you do not need to do any other processing, so Stop() is more appropriate. Use ParallelLoopState.Break() if you need to more closely match the behavior of the C# break statement. Both methods behave differently than our C# break statement. Unfortunately, when parallelizing a routine, more thought and care needs to be put into every aspect of your routine than you may otherwise expect. This is due to my second observation: Parallelizing a routine will almost always change its behavior. This sounds crazy at first, but it’s a concept that’s so simple its easy to forget. We’re purposely telling the system to process more than one thing at the same time, which means that the sequence in which things get processed is no longer deterministic. It is easy to change the behavior of your routine in very subtle ways by introducing parallelism. Often, the changes are not avoidable, even if they don’t have any adverse side effects. This leads to my final observation for this post: Parallelization is something that should be handled with care and forethought, added by design, and not just introduced casually.

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Can't get the L2TP IPSEC up and running

- by Maciej Swic

i have an Ubuntu 11.10 (oneiric) server running on a ReadyNAS. Im planning to use this to accept ipsec+l2tp connections through a router. However, the connection is failing somewhere half through. Using Openswan IPsec U2.6.28/K3.0.0-12-generic and trying to connect with an iOS 5 iPhone 4S. This is how far i can get: auth.log: Jan 19 13:54:11 ubuntu pluto[1990]: added connection description "PSK" Jan 19 13:54:11 ubuntu pluto[1990]: added connection description "L2TP-PSK-NAT" Jan 19 13:54:11 ubuntu pluto[1990]: added connection description "L2TP-PSK-noNAT" Jan 19 13:54:11 ubuntu pluto[1990]: added connection description "passthrough-for-non-l2tp" Jan 19 13:54:11 ubuntu pluto[1990]: listening for IKE messages Jan 19 13:54:11 ubuntu pluto[1990]: NAT-Traversal: Trying new style NAT-T Jan 19 13:54:11 ubuntu pluto[1990]: NAT-Traversal: ESPINUDP(1) setup failed for new style NAT-T family IPv4 (errno=19) Jan 19 13:54:11 ubuntu pluto[1990]: NAT-Traversal: Trying old style NAT-T Jan 19 13:54:11 ubuntu pluto[1990]: adding interface eth0/eth0 192.168.19.99:500 Jan 19 13:54:11 ubuntu pluto[1990]: adding interface eth0/eth0 192.168.19.99:4500 Jan 19 13:54:11 ubuntu pluto[1990]: adding interface lo/lo 127.0.0.1:500 Jan 19 13:54:11 ubuntu pluto[1990]: adding interface lo/lo 127.0.0.1:4500 Jan 19 13:54:11 ubuntu pluto[1990]: adding interface lo/lo ::1:500 Jan 19 13:54:11 ubuntu pluto[1990]: adding interface eth0/eth0 2001:470:28:81:a00:27ff:* Jan 19 13:54:11 ubuntu pluto[1990]: loading secrets from "/etc/ipsec.secrets" Jan 19 13:54:11 ubuntu pluto[1990]: loading secrets from "/var/lib/openswan/ipsec.secrets.inc" Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [RFC 3947] method set to=109 Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike] method set to=110 Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: ignoring unknown Vendor ID payload [8f8d83826d246b6fc7a8a6a428c11de8] Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: ignoring unknown Vendor ID payload [439b59f8ba676c4c7737ae22eab8f582] Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: ignoring unknown Vendor ID payload [4d1e0e136deafa34c4f3ea9f02ec7285] Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: ignoring unknown Vendor ID payload [80d0bb3def54565ee84645d4c85ce3ee] Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: ignoring unknown Vendor ID payload [9909b64eed937c6573de52ace952fa6b] Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-03] meth=108, but already using method 110 Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02] meth=107, but already using method 110 Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02_n] meth=106, but already using method 110 Jan 19 14:04:31 ubuntu pluto[1990]: packet from 95.*.*.233:500: received Vendor ID payload [Dead Peer Detection] Jan 19 14:04:31 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: responding to Main Mode from unknown peer 95.*.*.233 Jan 19 14:04:31 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1 Jan 19 14:04:31 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: STATE_MAIN_R1: sent MR1, expecting MI2 Jan 19 14:04:33 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: NAT-Traversal: Result using draft-ietf-ipsec-nat-t-ike (MacOS X): both are NATed Jan 19 14:04:33 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: transition from state STATE_MAIN_R1 to state STATE_MAIN_R2 Jan 19 14:04:33 ubuntu pluto[1990]: "PSK"[1] 95.*.*.233 #1: STATE_MAIN_R2: sent MR2, expecting MI3 Jan 19 14:05:03 ubuntu pluto[1990]: ERROR: asynchronous network error report on eth0 (sport=500) for message to 95.*.*.233 port 500, complainant 95.*.*.233: Connection refused [errno 111, origin ICMP type 3 code 3 (not authenticated)] Router config UDP 500, 1701 and 4500 forwarded to 192.168.19.99 (Ubuntu server for ipsec). Ipsec passthrough enabled. /etc/ipsec.conf # /etc/ipsec.conf - Openswan IPsec configuration file # This file: /usr/share/doc/openswan/ipsec.conf-sample # # Manual: ipsec.conf.5 version 2.0 # conforms to second version of ipsec.conf specification config setup nat_traversal=yes #charonstart=yes #plutostart=yes protostack=netkey conn PSK authby=secret forceencaps=yes pfs=no auto=add keyingtries=3 dpdtimeout=60 dpdaction=clear rekey=no left=192.168.19.99 leftnexthop=192.168.19.1 leftprotoport=17/1701 right=%any rightprotoport=17/%any rightsubnet=vhost:%priv,%no dpddelay=10 #dpdtimeout=10 #dpdaction=clear include /etc/ipsec.d/l2tp-psk.conf /etc/ipsec.d/l2tp-psk.conf conn L2TP-PSK-NAT rightsubnet=vhost:%priv also=L2TP-PSK-noNAT conn L2TP-PSK-noNAT # # PreSharedSecret needs to be specified in /etc/ipsec.secrets as # YourIPAddress %any: "sharedsecret" authby=secret pfs=no auto=add keyingtries=3 # we cannot rekey for %any, let client rekey rekey=no # Set ikelifetime and keylife to same defaults windows has ikelifetime=8h keylife=1h # l2tp-over-ipsec is transport mode type=transport # left=192.168.19.99 # # For updated Windows 2000/XP clients, # to support old clients as well, use leftprotoport=17/%any leftprotoport=17/1701 # # The remote user. # right=%any # Using the magic port of "0" means "any one single port". This is # a work around required for Apple OSX clients that use a randomly # high port, but propose "0" instead of their port. rightprotoport=17/%any dpddelay=10 dpdtimeout=10 dpdaction=clear conn passthrough-for-non-l2tp type=passthrough left=192.168.19.99 leftnexthop=192.168.19.1 right=0.0.0.0 rightsubnet=0.0.0.0/0 auto=route /etc/ipsec.secrets include /var/lib/openswan/ipsec.secrets.inc %any %any: PSK "my-key" 192.168.19.99 %any: PSK "my-key" /etc/xl2tpd/xl2tpd.conf [global] debug network = yes debug tunnel = yes ipsec saref = no listen-addr = 192.168.19.99 [lns default] ip range = 192.168.19.201-192.168.19.220 local ip = 192.168.19.99 require chap = yes refuse chap = no refuse pap = no require authentication = no ppp debug = yes pppoptfile = /etc/ppp/options.xl2tpd length bit = yes /etc/ppp/options.xl2tpd pcp-accept-local ipcp-accept-remote noccp auth crtscts idle 1800 mtu 1410 mru 1410 defaultroute debug lock proxyarp connect-delay 5000 ipcp-accept-local /etc/ppp/chap-secrets # Secrets for authentication using CHAP # client server secret IP addresses maciekish * my-secret * * maciekish my-secret * I can't seem to find the problem. Other ipsec connections to other hosts work from the network im currently at.

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Parallelism in .NET – Part 2, Simple Imperative Data Parallelism

- by Reed

In my discussion of Decomposition of the problem space, I mentioned that Data Decomposition is often the simplest abstraction to use when trying to parallelize a routine. If a problem can be decomposed based off the data, we will often want to use what MSDN refers to as Data Parallelism as our strategy for implementing our routine. The Task Parallel Library in .NET 4 makes implementing Data Parallelism, for most cases, very simple. Data Parallelism is the main technique we use to parallelize a routine which can be decomposed based off data. Data Parallelism refers to taking a single collection of data, and having a single operation be performed concurrently on elements in the collection. One side note here: Data Parallelism is also sometimes referred to as the Loop Parallelism Pattern or Loop-level Parallelism. In general, for this series, I will try to use the terminology used in the MSDN Documentation for the Task Parallel Library. This should make it easier to investigate these topics in more detail. Once we’ve determined we have a problem that, potentially, can be decomposed based on data, implementation using Data Parallelism in the TPL is quite simple. Let’s take our example from the Data Decomposition discussion – a simple contrast stretching filter. Here, we have a collection of data (pixels), and we need to run a simple operation on each element of the pixel. Once we know the minimum and maximum values, we most likely would have some simple code like the following: for (int row=0; row < pixelData.GetUpperBound(0); ++row) { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This simple routine loops through a two dimensional array of pixelData, and calls the AdjustContrast routine on each pixel. As I mentioned, when you’re decomposing a problem space, most iteration statements are potentially candidates for data decomposition. Here, we’re using two for loops – one looping through rows in the image, and a second nested loop iterating through the columns. We then perform one, independent operation on each element based on those loop positions. This is a prime candidate – we have no shared data, no dependencies on anything but the pixel which we want to change. Since we’re using a for loop, we can easily parallelize this using the Parallel.For method in the TPL: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Here, by simply changing our first for loop to a call to Parallel.For, we can parallelize this portion of our routine. Parallel.For works, as do many methods in the TPL, by creating a delegate and using it as an argument to a method. In this case, our for loop iteration block becomes a delegate creating via a lambda expression. This lets you write code that, superficially, looks similar to the familiar for loop, but functions quite differently at runtime. We could easily do this to our second for loop as well, but that may not be a good idea. There is a balance to be struck when writing parallel code. We want to have enough work items to keep all of our processors busy, but the more we partition our data, the more overhead we introduce. In this case, we have an image of data – most likely hundreds of pixels in both dimensions. By just parallelizing our first loop, each row of pixels can be run as a single task. With hundreds of rows of data, we are providing fine enough granularity to keep all of our processors busy. If we parallelize both loops, we’re potentially creating millions of independent tasks. This introduces extra overhead with no extra gain, and will actually reduce our overall performance. This leads to my first guideline when writing parallel code: Partition your problem into enough tasks to keep each processor busy throughout the operation, but not more than necessary to keep each processor busy. Also note that I parallelized the outer loop. I could have just as easily partitioned the inner loop. However, partitioning the inner loop would have led to many more discrete work items, each with a smaller amount of work (operate on one pixel instead of one row of pixels). My second guideline when writing parallel code reflects this: Partition your problem in a way to place the most work possible into each task. This typically means, in practice, that you will want to parallelize the routine at the “highest” point possible in the routine, typically the outermost loop. If you’re looking at parallelizing methods which call other methods, you’ll want to try to partition your work high up in the stack – as you get into lower level methods, the performance impact of parallelizing your routines may not overcome the overhead introduced. Parallel.For works great for situations where we know the number of elements we’re going to process in advance. If we’re iterating through an IList<T> or an array, this is a typical approach. However, there are other iteration statements common in C#. In many situations, we’ll use foreach instead of a for loop. This can be more understandable and easier to read, but also has the advantage of working with collections which only implement IEnumerable<T>, where we do not know the number of elements involved in advance. As an example, lets take the following situation. Say we have a collection of Customers, and we want to iterate through each customer, check some information about the customer, and if a certain case is met, send an email to the customer and update our instance to reflect this change. Normally, this might look something like: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } } Here, we’re doing a fair amount of work for each customer in our collection, but we don’t know how many customers exist. If we assume that theStore.GetLastContact(customer) and theStore.EmailCustomer(customer) are both side-effect free, thread safe operations, we could parallelize this using Parallel.ForEach: Parallel.ForEach(customers, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); Just like Parallel.For, we rework our loop into a method call accepting a delegate created via a lambda expression. This keeps our new code very similar to our original iteration statement, however, this will now execute in parallel. The same guidelines apply with Parallel.ForEach as with Parallel.For. The other iteration statements, do and while, do not have direct equivalents in the Task Parallel Library. These, however, are very easy to implement using Parallel.ForEach and the yield keyword. Most applications can benefit from implementing some form of Data Parallelism. Iterating through collections and performing “work” is a very common pattern in nearly every application. When the problem can be decomposed by data, we often can parallelize the workload by merely changing foreach statements to Parallel.ForEach method calls, and for loops to Parallel.For method calls. Any time your program operates on a collection, and does a set of work on each item in the collection where that work is not dependent on other information, you very likely have an opportunity to parallelize your routine.

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Ubuntu 12.04 + Eclipse 64 bits key binding error

- by user110933

The text is quite extense so, this is just a part of it: !SESSION 2012-11-23 10:15:52.442 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 10:16:06.408 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 10:16:06.408 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.ui.workbench 4 0 2012-11-23 10:16:10.409 !MESSAGE An unexpected exception was thrown. !STACK 0 java.lang.NullPointerException at org.eclipse.ui.internal.WorkbenchWindow.putToolbarLabel(WorkbenchWindow.java:1697) at org.eclipse.ui.internal.menus.MenuAdditionCacheEntry.createToolBarAdditionContribution(MenuAdditionCacheEntry.java:208) at org.eclipse.ui.internal.menus.MenuAdditionCacheEntry.createContributionItems(MenuAdditionCacheEntry.java:177) at org.eclipse.ui.internal.menus.TrimContributionManager.update(TrimContributionManager.java:224) at org.eclipse.ui.internal.WorkbenchWindow.updateLayoutDataForContents(WorkbenchWindow.java:3874) at org.eclipse.ui.internal.WorkbenchWindow.setCoolBarVisible(WorkbenchWindow.java:3675) at org.eclipse.ui.internal.ViewIntroAdapterPart.setBarVisibility(ViewIntroAdapterPart.java:203) at org.eclipse.ui.internal.ViewIntroAdapterPart.dispose(ViewIntroAdapterPart.java:106) at org.eclipse.ui.internal.WorkbenchPartReference.doDisposePart(WorkbenchPartReference.java:737) at org.eclipse.ui.internal.ViewReference.doDisposePart(ViewReference.java:107) at org.eclipse.ui.internal.WorkbenchPartReference.dispose(WorkbenchPartReference.java:684) at org.eclipse.ui.internal.WorkbenchPage.disposePart(WorkbenchPage.java:1801) at org.eclipse.ui.internal.WorkbenchPage.partRemoved(WorkbenchPage.java:1793) at org.eclipse.ui.internal.ViewFactory.releaseView(ViewFactory.java:257) at org.eclipse.ui.internal.Perspective.dispose(Perspective.java:292) at org.eclipse.ui.internal.WorkbenchPage.dispose(WorkbenchPage.java:1872) at org.eclipse.ui.internal.WorkbenchWindow.closeAllPages(WorkbenchWindow.java:894) at org.eclipse.ui.internal.WorkbenchWindow.hardClose(WorkbenchWindow.java:1729) at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:730) at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:715) at org.eclipse.ui.internal.WorkbenchWindow$6.run(WorkbenchWindow.java:867) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:865) at org.eclipse.jface.window.WindowManager.close(WindowManager.java:109) at org.eclipse.ui.internal.Workbench$18.run(Workbench.java:1114) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.Workbench.busyClose(Workbench.java:1111) at org.eclipse.ui.internal.Workbench.access$15(Workbench.java:1040) at org.eclipse.ui.internal.Workbench$25.run(Workbench.java:1284) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.Workbench.close(Workbench.java:1282) at org.eclipse.ui.internal.Workbench.close(Workbench.java:1254) at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:727) at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:715) at org.eclipse.ui.internal.WorkbenchWindow$6.run(WorkbenchWindow.java:867) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:865) at org.eclipse.jface.window.Window.handleShellCloseEvent(Window.java:741) at org.eclipse.jface.window.Window$3.shellClosed(Window.java:687) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:98) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1276) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1300) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1285) at org.eclipse.swt.widgets.Shell.closeWidget(Shell.java:617) at org.eclipse.swt.widgets.Shell.gtk_delete_event(Shell.java:1191) at org.eclipse.swt.widgets.Widget.windowProc(Widget.java:1750) at org.eclipse.swt.widgets.Control.windowProc(Control.java:5116) at org.eclipse.swt.widgets.Display.windowProc(Display.java:4369) at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method) at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(OS.java:8295) at org.eclipse.swt.widgets.Display.eventProc(Display.java:1192) at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method) at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:2332) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3177) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499) at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584) at org.eclipse.equinox.launcher.Main.run(Main.java:1438) at org.eclipse.equinox.launcher.Main.main(Main.java:1414) !SESSION 2012-11-23 10:36:07.863 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 10:36:13.181 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 10:36:13.181 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.osgi 2 1 2012-11-23 10:39:04.681 !MESSAGE NLS unused message: CacheManager_CannotLoadNonUrlLocation in: org.eclipse.equinox.internal.p2.repository.messages !SESSION 2012-11-23 15:14:12.933 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:14:23.380 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:14:23.380 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.springframework.ide.eclipse.uaa 4 2 2012-11-23 15:14:32.800 !MESSAGE Problems occurred when invoking code from plug-in: "org.springframework.ide.eclipse.uaa". !STACK 0 java.lang.NullPointerException at org.springframework.ide.eclipse.internal.uaa.monitor.CommandUsageMonitor.startMonitoring(CommandUsageMonitor.java:61) at org.springframework.ide.eclipse.uaa.UaaPlugin$1$1.run(UaaPlugin.java:91) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.springframework.ide.eclipse.uaa.UaaPlugin$1.run(UaaPlugin.java:85) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54) !SESSION 2012-11-23 15:15:21.833 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:15:27.283 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:15:27.283 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.jface 2 0 2012-11-23 15:18:41.265 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:18:41.265 !MESSAGE A conflict occurred for ALT+SHIFT+E: Binding(ALT+SHIFT+E, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.wst.jsdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.wst.jsdt.ui.category.refactoring,Refactor - JavaScript,JavaScript Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) !SESSION 2012-11-23 15:18:56.267 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:19:01.605 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:19:01.605 !MESSAGE A conflict occurred for ALT+SHIFT+E: Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.wst.jsdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.wst.jsdt.ui.category.refactoring,Refactor - JavaScript,JavaScript Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user)

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Parallelism in .NET – Part 11, Divide and Conquer via Parallel.Invoke

- by Reed

Many algorithms are easily written to work via recursion. For example, most data-oriented tasks where a tree of data must be processed are much more easily handled by starting at the root, and recursively “walking” the tree. Some algorithms work this way on flat data structures, such as arrays, as well. This is a form of divide and conquer: an algorithm design which is based around breaking up a set of work recursively, “dividing” the total work in each recursive step, and “conquering” the work when the remaining work is small enough to be solved easily. Recursive algorithms, especially ones based on a form of divide and conquer, are often a very good candidate for parallelization. This is apparent from a common sense standpoint. Since we’re dividing up the total work in the algorithm, we have an obvious, built-in partitioning scheme. Once partitioned, the data can be worked upon independently, so there is good, clean isolation of data. Implementing this type of algorithm is fairly simple. The Parallel class in .NET 4 includes a method suited for this type of operation: Parallel.Invoke. This method works by taking any number of delegates defined as an Action, and operating them all in parallel. The method returns when every delegate has completed: Parallel.Invoke( () => { Console.WriteLine("Action 1 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 2 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 3 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); } ); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Running this simple example demonstrates the ease of using this method. For example, on my system, I get three separate thread IDs when running the above code. By allowing any number of delegates to be executed directly, concurrently, the Parallel.Invoke method provides us an easy way to parallelize any algorithm based on divide and conquer. We can divide our work in each step, and execute each task in parallel, recursively. For example, suppose we wanted to implement our own quicksort routine. The quicksort algorithm can be designed based on divide and conquer. In each iteration, we pick a pivot point, and use that to partition the total array. We swap the elements around the pivot, then recursively sort the lists on each side of the pivot. For example, let’s look at this simple, sequential implementation of quicksort: public static void QuickSort<T>(T[] array) where T : IComparable<T> { QuickSortInternal(array, 0, array.Length - 1); } private static void QuickSortInternal<T>(T[] array, int left, int right) where T : IComparable<T> { if (left >= right) { return; } SwapElements(array, left, (left + right) / 2); int last = left; for (int current = left + 1; current <= right; ++current) { if (array[current].CompareTo(array[left]) < 0) { ++last; SwapElements(array, last, current); } } SwapElements(array, left, last); QuickSortInternal(array, left, last - 1); QuickSortInternal(array, last + 1, right); } static void SwapElements<T>(T[] array, int i, int j) { T temp = array[i]; array[i] = array[j]; array[j] = temp; } Here, we implement the quicksort algorithm in a very common, divide and conquer approach. Running this against the built-in Array.Sort routine shows that we get the exact same answers (although the framework’s sort routine is slightly faster). On my system, for example, I can use framework’s sort to sort ten million random doubles in about 7.3s, and this implementation takes about 9.3s on average. Looking at this routine, though, there is a clear opportunity to parallelize. At the end of QuickSortInternal, we recursively call into QuickSortInternal with each partition of the array after the pivot is chosen. This can be rewritten to use Parallel.Invoke by simply changing it to: // Code above is unchanged... SwapElements(array, left, last); Parallel.Invoke( () => QuickSortInternal(array, left, last - 1), () => QuickSortInternal(array, last + 1, right) ); } This routine will now run in parallel. When executing, we now see the CPU usage across all cores spike while it executes. However, there is a significant problem here – by parallelizing this routine, we took it from an execution time of 9.3s to an execution time of approximately 14 seconds! We’re using more resources as seen in the CPU usage, but the overall result is a dramatic slowdown in overall processing time. This occurs because parallelization adds overhead. Each time we split this array, we spawn two new tasks to parallelize this algorithm! This is far, far too many tasks for our cores to operate upon at a single time. In effect, we’re “over-parallelizing” this routine. This is a common problem when working with divide and conquer algorithms, and leads to an important observation: When parallelizing a recursive routine, take special care not to add more tasks than necessary to fully utilize your system. This can be done with a few different approaches, in this case. Typically, the way to handle this is to stop parallelizing the routine at a certain point, and revert back to the serial approach. Since the first few recursions will all still be parallelized, our “deeper” recursive tasks will be running in parallel, and can take full advantage of the machine. This also dramatically reduces the overhead added by parallelizing, since we’re only adding overhead for the first few recursive calls. There are two basic approaches we can take here. The first approach would be to look at the total work size, and if it’s smaller than a specific threshold, revert to our serial implementation. In this case, we could just check right-left, and if it’s under a threshold, call the methods directly instead of using Parallel.Invoke. The second approach is to track how “deep” in the “tree” we are currently at, and if we are below some number of levels, stop parallelizing. This approach is a more general-purpose approach, since it works on routines which parse trees as well as routines working off of a single array, but may not work as well if a poor partitioning strategy is chosen or the tree is not balanced evenly. This can be written very easily. If we pass a maxDepth parameter into our internal routine, we can restrict the amount of times we parallelize by changing the recursive call to: // Code above is unchanged... SwapElements(array, left, last); if (maxDepth < 1) { QuickSortInternal(array, left, last - 1, maxDepth); QuickSortInternal(array, last + 1, right, maxDepth); } else { --maxDepth; Parallel.Invoke( () => QuickSortInternal(array, left, last - 1, maxDepth), () => QuickSortInternal(array, last + 1, right, maxDepth)); } We no longer allow this to parallelize indefinitely – only to a specific depth, at which time we revert to a serial implementation. By starting the routine with a maxDepth equal to Environment.ProcessorCount, we can restrict the total amount of parallel operations significantly, but still provide adequate work for each processing core. With this final change, my timings are much better. On average, I get the following timings: Framework via Array.Sort: 7.3 seconds Serial Quicksort Implementation: 9.3 seconds Naive Parallel Implementation: 14 seconds Parallel Implementation Restricting Depth: 4.7 seconds Finally, we are now faster than the framework’s Array.Sort implementation.

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SQL SERVER – Copy Data from One Table to Another Table – SQL in Sixty Seconds #031 – Video

- by pinaldave

Copy data from one table to another table is one of the most requested questions on forums, Facebook and Twitter. The question has come in many formats and there are places I have seen developers are using cursor instead of this direct method. Earlier I have written the similar article a few years ago - SQL SERVER – Insert Data From One Table to Another Table – INSERT INTO SELECT – SELECT INTO TABLE. The article has been very popular and I have received many interesting and constructive comments. However there were two specific comments keep on ending up on my mailbox. 1) SQL Server AdventureWorks Samples Database does not have table I used in the example 2) If there is a video tutorial of the same example. After carefully thinking I decided to build a new set of the scripts for the example which are very similar to the old one as well video tutorial of the same. There was no better place than our SQL in Sixty Second Series to cover this interesting small concept. Let me know what you think of this video. Here is the updated script. -- Method 1 : INSERT INTO SELECT USE AdventureWorks2012 GO ----Create TestTable CREATE TABLE TestTable (FirstName VARCHAR(100), LastName VARCHAR(100)) ----INSERT INTO TestTable using SELECT INSERT INTO TestTable (FirstName, LastName) SELECT FirstName, LastName FROM Person.Person WHERE EmailPromotion = 2 ----Verify that Data in TestTable SELECT FirstName, LastName FROM TestTable ----Clean Up Database DROP TABLE TestTable GO --------------------------------------------------------- --------------------------------------------------------- -- Method 2 : SELECT INTO USE AdventureWorks2012 GO ----Create new table and insert into table using SELECT INSERT SELECT FirstName, LastName INTO TestTable FROM Person.Person WHERE EmailPromotion = 2 ----Verify that Data in TestTable SELECT FirstName, LastName FROM TestTable ----Clean Up Database DROP TABLE TestTable GO Related Tips in SQL in Sixty Seconds: SQL SERVER – Insert Data From One Table to Another Table – INSERT INTO SELECT – SELECT INTO TABLE Powershell – Importing CSV File Into Database – Video SQL SERVER – 2005 – Export Data From SQL Server 2005 to Microsoft Excel Datasheet SQL SERVER – Import CSV File into Database Table Using SSIS SQL SERVER – Import CSV File Into SQL Server Using Bulk Insert – Load Comma Delimited File Into SQL Server SQL SERVER – 2005 – Generate Script with Data from Database – Database Publishing Wizard What would you like to see in the next SQL in Sixty Seconds video? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Excel

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Manage Files Easier With Aero Snap in Windows 7

- by Mysticgeek

Before the days of Aero Snap you would need to arrange your Windows in some weird way to see all of your files. Today we show you how to quickly use the Aero Snap feature get it done in few key strokes in Windows 7. You can of course navigate the windows in Explorer to get them so you can see everything side by side, or use a free utility like Cubic Explorer. Getting Explorer Windows Side by Side The process is actually simple but quite useful when looking for a large amount of data. Right-click the Windows Explorer icon on the taskbar and click Windows Explorer. Our first window opens up and you can certainly drag it over the the right or left side of the screen but the quickest method we’re using is the “Windows Key+Right Arrow” key combo (make sure to hold the Windows key down). Now the Windows is nicely placed on the right side. Next we want to open the other window, simply right-click the Explorer icon again and click Windows Explorer. Now we have our second window open, and all we need to do this time is use the Windows Key+Left Arrow combination. There we go! Now you should be able to browse your files a lot more simply than relying on the expanding tree method (as much). You can actually use this method to snap a window to all four corners of your screen if you don’t feel like dragging it. Once you play with Aero Snap more you may enjoy it, but if you still despise it, you can disable it too! Similar Articles Productive Geek Tips Multitask Like a Pro with AquaSnapUse Windows Vista Aero through Remote Desktop ConnectionEasily Disable Win 7 or Vista’s Aero Before Running an Application (Such as a Video Game)Understanding Windows Vista Aero Glass RequirementsFree Storage With AOL’s Xdrive (Online Storage Series) TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Awesome Lyrics Finder for Winamp & Windows Media Player Download Videos from Hulu Pixels invade Manhattan Convert PDF files to ePub to read on your iPad Hide Your Confidential Files Inside Images Get Wildlife Photography Tips at BBC’s PhotoMasterClasses

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MVC 2 Editor Template for Radio Buttons

- by Steve Michelotti

A while back I blogged about how to create an HTML Helper to produce a radio button list. In that post, my HTML helper was “wrapping” the FluentHtml library from MvcContrib to produce the following html output (given an IEnumerable list containing the items “Foo” and “Bar”): 1: <div> 2: <input id="Name_Foo" name="Name" type="radio" value="Foo" /><label for="Name_Foo" id="Name_Foo_Label">Foo</label> 3: <input id="Name_Bar" name="Name" type="radio" value="Bar" /><label for="Name_Bar" id="Name_Bar_Label">Bar</label> 4: </div> With the release of MVC 2, we now have editor templates we can use that rely on metadata to allow us to customize our views appropriately. For example, for the radio buttons above, we want the “id” attribute to be differentiated and unique and we want the “name” attribute to be the same across radio buttons so the buttons will be grouped together and so model binding will work appropriately. We also want the “for” attribute in the <label> element being set to correctly point to the id of the corresponding radio button. The default behavior of the RadioButtonFor() method that comes OOTB with MVC produces the same value for the “id” and “name” attributes so this isn’t exactly what I want out the the box if I’m trying to produce the HTML mark up above. If we use an EditorTemplate, the first gotcha that we run into is that, by default, the templates just work on your view model’s property. But in this case, we *also* was the list of items to populate all the radio buttons. It turns out that the EditorFor() methods do give you a way to pass in additional data. There is an overload of the EditorFor() method where the last parameter allows you to pass an anonymous object for “extra” data that you can use in your view – it gets put on the view data dictionary: 1: <%: Html.EditorFor(m => m.Name, "RadioButtonList", new { selectList = new SelectList(new[] { "Foo", "Bar" }) })%> Now we can create a file called RadioButtonList.ascx that looks like this: 1: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> 2: <% 3: var list = this.ViewData["selectList"] as SelectList; 4: %> 5: <div> 6: <% foreach (var item in list) { 7: var radioId = ViewData.TemplateInfo.GetFullHtmlFieldId(item.Value); 8: var checkedAttr = item.Selected ? "checked=\"checked\"" : string.Empty; 9: %> 10: <input type="radio" id="<%: radioId %>" name="<%: ViewData.TemplateInfo.HtmlFieldPrefix %>" value="<%: item.Value %>" <%: checkedAttr %>/> 11: <label for="<%: radioId %>"><%: item.Text %></label> 12: <% } %> 13: </div> There are several things to note about the code above. First, you can see in line #3, it’s getting the SelectList out of the view data dictionary. Then on line #7 it uses the GetFullHtmlFieldId() method from the TemplateInfo class to ensure we get unique IDs. We pass the Value to this method so that it will produce IDs like “Name_Foo” and “Name_Bar” rather than just “Name” which is our property name. However, for the “name” attribute (on line #10) we can just use the normal HtmlFieldPrefix property so that we ensure all radio buttons have the same name which corresponds to the view model’s property name. We also get to leverage the fact the a SelectListItem has a Boolean Selected property so we can set the checkedAttr variable on line #8 and use it on line #10. Finally, it’s trivial to set the correct “for” attribute for the <label> on line #11 since we already produced that value. Because the TemplateInfo class provides all the metadata for our view, we’re able to produce this view that is widely re-usable across our application. In fact, we can create a couple HTML helpers to better encapsulate this call and make it more user friendly: 1: public static MvcHtmlString RadioButtonList<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, params string[] items) 2: { 3: return htmlHelper.RadioButtonList(expression, new SelectList(items)); 4: } 5: 6: public static MvcHtmlString RadioButtonList<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> items) 7: { 8: var func = expression.Compile(); 9: var result = func(htmlHelper.ViewData.Model); 10: var list = new SelectList(items, "Value", "Text", result); 11: return htmlHelper.EditorFor(expression, "RadioButtonList", new { selectList = list }); 12: } This allows us to simply the call like this: 1: <%: Html.RadioButtonList(m => m.Name, "Foo", "Bar" ) %> In that example, the values for the radio button are hard-coded and being passed in directly. But if you had a view model that contained a property for the collection of items you could call the second overload like this: 1: <%: Html.RadioButtonList(m => m.Name, Model.FooBarList ) %> The Editor templates introduced in MVC 2 definitely allow for much more flexible views/editors than previously available. By knowing about the features you have available to you with the TemplateInfo class, you can take these concepts and customize your editors with extreme flexibility and re-usability.

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SignalR Auto Disconnect when Page Changed in AngularJS

- by Shaun

Originally posted on: http://geekswithblogs.net/shaunxu/archive/2014/05/30/signalr-auto-disconnect-when-page-changed-in-angularjs.aspxIf we are using SignalR, the connection lifecycle was handled by itself very well. For example when we connect to SignalR service from browser through SignalR JavaScript Client the connection will be established. And if we refresh the page, close the tab or browser, or navigate to another URL then the connection will be closed automatically. This information had been well documented here. In a browser, SignalR client code that maintains a SignalR connection runs in the JavaScript context of a web page. That's why the SignalR connection has to end when you navigate from one page to another, and that's why you have multiple connections with multiple connection IDs if you connect from multiple browser windows or tabs. When the user closes a browser window or tab, or navigates to a new page or refreshes the page, the SignalR connection immediately ends because SignalR client code handles that browser event for you and calls the "Stop" method. But unfortunately this behavior doesn't work if we are using SignalR with AngularJS. AngularJS is a single page application (SPA) framework created by Google. It hijacks browser's address change event, based on the route table user defined, launch proper view and controller. Hence in AngularJS we address was changed but the web page still there. All changes of the page content are triggered by Ajax. So there's no page unload and load events. This is the reason why SignalR cannot handle disconnect correctly when works with AngularJS. If we dig into the source code of SignalR JavaScript Client source code we will find something below. It monitors the browser page "unload" and "beforeunload" event and send the "stop" message to server to terminate connection. But in AngularJS page change events were hijacked, so SignalR will not receive them and will not stop the connection. 1: // wire the stop handler for when the user leaves the page 2: _pageWindow.bind("unload", function () { 3: connection.log("Window unloading, stopping the connection."); 4: 5: connection.stop(asyncAbort); 6: }); 7: 8: if (isFirefox11OrGreater) { 9: // Firefox does not fire cross-domain XHRs in the normal unload handler on tab close. 10: // #2400 11: _pageWindow.bind("beforeunload", function () { 12: // If connection.stop() runs runs in beforeunload and fails, it will also fail 13: // in unload unless connection.stop() runs after a timeout. 14: window.setTimeout(function () { 15: connection.stop(asyncAbort); 16: }, 0); 17: }); 18: } Problem Reproduce In the codes below I created a very simple example to demonstrate this issue. Here is the SignalR server side code. 1: public class GreetingHub : Hub 2: { 3: public override Task OnConnected() 4: { 5: Debug.WriteLine(string.Format("Connected: {0}", Context.ConnectionId)); 6: return base.OnConnected(); 7: } 8: 9: public override Task OnDisconnected() 10: { 11: Debug.WriteLine(string.Format("Disconnected: {0}", Context.ConnectionId)); 12: return base.OnDisconnected(); 13: } 14: 15: public void Hello(string user) 16: { 17: Clients.All.hello(string.Format("Hello, {0}!", user)); 18: } 19: } Below is the configuration code which hosts SignalR hub in an ASP.NET WebAPI project with IIS Express. 1: public class Startup 2: { 3: public void Configuration(IAppBuilder app) 4: { 5: app.Map("/signalr", map => 6: { 7: map.UseCors(CorsOptions.AllowAll); 8: map.RunSignalR(new HubConfiguration() 9: { 10: EnableJavaScriptProxies = false 11: }); 12: }); 13: } 14: } Since we will host AngularJS application in Node.js in another process and port, the SignalR connection will be cross domain. So I need to enable CORS above. In client side I have a Node.js file to host AngularJS application as a web server. You can use any web server you like such as IIS, Apache, etc.. Below is the "index.html" page which contains a navigation bar so that I can change the page/state. As you can see I added jQuery, AngularJS, SignalR JavaScript Client Library as well as my AngularJS entry source file "app.js". 1: <html data-ng-app="demo"> 2: <head> 3: <script type="text/javascript" src="jquery-2.1.0.js"></script> 1: 2: <script type="text/javascript" src="angular.js"> 1: </script> 2: <script type="text/javascript" src="angular-ui-router.js"> 1: </script> 2: <script type="text/javascript" src="jquery.signalR-2.0.3.js"> 1: </script> 2: <script type="text/javascript" src="app.js"></script> 4: </head> 5: <body> 6: <h1>SignalR Auto Disconnect with AngularJS by Shaun</h1> 7: <div> 8: <a href="javascript:void(0)" data-ui-sref="view1">View 1</a> | 9: <a href="javascript:void(0)" data-ui-sref="view2">View 2</a> 10: </div> 11: <div data-ui-view></div> 12: </body> 13: </html> Below is the "app.js". My SignalR logic was in the "View1" page and it will connect to server once the controller was executed. User can specify a user name and send to server, all clients that located in this page will receive the server side greeting message through SignalR. 1: 'use strict'; 2: 3: var app = angular.module('demo', ['ui.router']); 4: 5: app.config(['$stateProvider', '$locationProvider', function ($stateProvider, $locationProvider) { 6: $stateProvider.state('view1', { 7: url: '/view1', 8: templateUrl: 'view1.html', 9: controller: 'View1Ctrl' }); 10: 11: $stateProvider.state('view2', { 12: url: '/view2', 13: templateUrl: 'view2.html', 14: controller: 'View2Ctrl' }); 15: 16: $locationProvider.html5Mode(true); 17: }]); 18: 19: app.value('$', $); 20: app.value('endpoint', 'http://localhost:60448'); 21: app.value('hub', 'GreetingHub'); 22: 23: app.controller('View1Ctrl', function ($scope, $, endpoint, hub) { 24: $scope.user = ''; 25: $scope.response = ''; 26: 27: $scope.greeting = function () { 28: proxy.invoke('Hello', $scope.user) 29: .done(function () {}) 30: .fail(function (error) { 31: console.log(error); 32: }); 33: }; 34: 35: var connection = $.hubConnection(endpoint); 36: var proxy = connection.createHubProxy(hub); 37: proxy.on('hello', function (response) { 38: $scope.$apply(function () { 39: $scope.response = response; 40: }); 41: }); 42: connection.start() 43: .done(function () { 44: console.log('signlar connection established'); 45: }) 46: .fail(function (error) { 47: console.log(error); 48: }); 49: }); 50: 51: app.controller('View2Ctrl', function ($scope, $) { 52: }); When we went to View1 the server side "OnConnect" method will be invoked as below. And in any page we send the message to server, all clients will got the response. If we close one of the client, the server side "OnDisconnect" method will be invoked which is correct. But is we click "View 2" link in the page "OnDisconnect" method will not be invoked even though the content and browser address had been changed. This might cause many SignalR connections remain between the client and server. Below is what happened after I clicked "View 1" and "View 2" links four times. As you can see there are 4 live connections. Solution Since the reason of this issue is because, AngularJS hijacks the page event that SignalR need to stop the connection, we can handle AngularJS route or state change event and stop SignalR connect manually. In the code below I moved the "connection" variant to global scope, added a handler to "$stateChangeStart" and invoked "stop" method of "connection" if its state was not "disconnected". 1: var connection; 2: app.run(['$rootScope', function ($rootScope) { 3: $rootScope.$on('$stateChangeStart', function () { 4: if (connection && connection.state && connection.state !== 4 /* disconnected */) { 5: console.log('signlar connection abort'); 6: connection.stop(); 7: } 8: }); 9: }]); Now if we refresh the page and navigated to View 1, the connection will be opened. At this state if we clicked "View 2" link the content will be changed and the SignalR connection will be closed automatically. Summary In this post I demonstrated an issue when we are using SignalR with AngularJS. The connection cannot be closed automatically when we navigate to other page/state in AngularJS. And the solution I mentioned below is to move the SignalR connection as a global variant and close it manually when AngularJS route/state changed. You can download the full sample code here. Moving the SignalR connection as a global variant might not be a best solution. It's just for easy to demo here. In production code I suggest wrapping all SignalR operations into an AngularJS factory. Since AngularJS factory is a singleton object, we can safely put the connection variant in the factory function scope. Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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Entity Framework Code-First, OData & Windows Phone Client

- by Jon Galloway

Entity Framework Code-First is the coolest thing since sliced bread, Windows Phone is the hottest thing since Tickle-Me-Elmo and OData is just too great to ignore. As part of the Full Stack project, we wanted to put them together, which turns out to be pretty easy… once you know how. EF Code-First CTP5 is available now and there should be very few breaking changes in the release edition, which is due early in 2011. Note: EF Code-First evolved rapidly and many of the existing documents and blog posts which were written with earlier versions, may now be obsolete or at least misleading. Code-First? With traditional Entity Framework you start with a database and from that you generate “entities” – classes that bridge between the relational database and your object oriented program. With Code-First (Magic-Unicorn) (see Hanselman’s write up and this later write up by Scott Guthrie) the Entity Framework looks at classes you created and says “if I had created these classes, the database would have to have looked like this…” and creates the database for you! By deriving your entity collections from DbSet and exposing them via a class that derives from DbContext, you "turn on" database backing for your POCO with a minimum of code and no hidden designer or configuration files. POCO == Plain Old CLR Objects Your entity objects can be used throughout your applications - in web applications, console applications, Silverlight and Windows Phone applications, etc. In our case, we'll want to read and update data from a Windows Phone client application, so we'll expose the entities through a DataService and hook the Windows Phone client application to that data via proxies. Piece of Pie. Easy as cake. The Demo Architecture To see this at work, we’ll create an ASP.NET/MVC application which will act as the host for our Data Service. We’ll create an incredibly simple data layer using EF Code-First on top of SQLCE4 and we’ll expose the data in a WCF Data Service using the oData protocol. Our Windows Phone 7 client will instantiate the data context via a URI and load the data asynchronously. Setting up the Server project with MVC 3, EF Code First, and SQL CE 4 Create a new application of type ASP.NET MVC 3 and name it DeadSimpleServer. We need to add the latest SQLCE4 and Entity Framework Code First CTP's to our project. Fortunately, NuGet makes that really easy. Open the Package Manager Console (View / Other Windows / Package Manager Console) and type in "Install-Package EFCodeFirst.SqlServerCompact" at the PM> command prompt. Since NuGet handles dependencies for you, you'll see that it installs everything you need to use Entity Framework Code First in your project. PM> install-package EFCodeFirst.SqlServerCompact 'SQLCE (= 4.0.8435.1)' not installed. Attempting to retrieve dependency from source... Done 'EFCodeFirst (= 0.8)' not installed. Attempting to retrieve dependency from source... Done 'WebActivator (= 1.0.0.0)' not installed. Attempting to retrieve dependency from source... Done You are downloading SQLCE from Microsoft, the license agreement to which is available at http://173.203.67.148/licenses/SQLCE/EULA_ENU.rtf. Check the package for additional dependencies, which may come with their own license agreement(s). Your use of the package and dependencies constitutes your acceptance of their license agreements. If you do not accept the license agreement(s), then delete the relevant components from your device. Successfully installed 'SQLCE 4.0.8435.1' You are downloading EFCodeFirst from Microsoft, the license agreement to which is available at http://go.microsoft.com/fwlink/?LinkID=206497. Check the package for additional dependencies, which may come with their own license agreement(s). Your use of the package and dependencies constitutes your acceptance of their license agreements. If you do not accept the license agreement(s), then delete the relevant components from your device. Successfully installed 'EFCodeFirst 0.8' Successfully installed 'WebActivator 1.0.0.0' You are downloading EFCodeFirst.SqlServerCompact from Microsoft, the license agreement to which is available at http://173.203.67.148/licenses/SQLCE/EULA_ENU.rtf. Check the package for additional dependencies, which may come with their own license agreement(s). Your use of the package and dependencies constitutes your acceptance of their license agreements. If you do not accept the license agreement(s), then delete the relevant components from your device. Successfully installed 'EFCodeFirst.SqlServerCompact 0.8' Successfully added 'SQLCE 4.0.8435.1' to EfCodeFirst-CTP5 Successfully added 'EFCodeFirst 0.8' to EfCodeFirst-CTP5 Successfully added 'WebActivator 1.0.0.0' to EfCodeFirst-CTP5 Successfully added 'EFCodeFirst.SqlServerCompact 0.8' to EfCodeFirst-CTP5 Note: We're using SQLCE 4 with Entity Framework here because they work really well together from a development scenario, but you can of course use Entity Framework Code First with other databases supported by Entity framework. Creating The Model using EF Code First Now we can create our model class. Right-click the Models folder and select Add/Class. Name the Class Person.cs and add the following code: using System.Data.Entity; namespace DeadSimpleServer.Models { public class Person { public int ID { get; set; } public string Name { get; set; } } public class PersonContext : DbContext { public DbSet<Person> People { get; set; } } } Notice that the entity class Person has no special interfaces or base class. There's nothing special needed to make it work - it's just a POCO. The context we'll use to access the entities in the application is called PersonContext, but you could name it anything you wanted. The important thing is that it inherits DbContext and contains one or more DbSet which holds our entity collections. Adding Seed Data We need some testing data to expose from our service. The simplest way to get that into our database is to modify the CreateCeDatabaseIfNotExists class in AppStart_SQLCEEntityFramework.cs by adding some seed data to the Seed method: protected virtual void Seed( TContext context ) { var personContext = context as PersonContext; personContext.People.Add( new Person { ID = 1, Name = "George Washington" } ); personContext.People.Add( new Person { ID = 2, Name = "John Adams" } ); personContext.People.Add( new Person { ID = 3, Name = "Thomas Jefferson" } ); personContext.SaveChanges(); } The CreateCeDatabaseIfNotExists class name is pretty self-explanatory - when our DbContext is accessed and the database isn't found, a new one will be created and populated with the data in the Seed method. There's one more step to make that work - we need to uncomment a line in the Start method at the top of of the AppStart_SQLCEEntityFramework class and set the context name, as shown here, public static class AppStart_SQLCEEntityFramework { public static void Start() { DbDatabase.DefaultConnectionFactory = new SqlCeConnectionFactory("System.Data.SqlServerCe.4.0"); // Sets the default database initialization code for working with Sql Server Compact databases // Uncomment this line and replace CONTEXT_NAME with the name of your DbContext if you are // using your DbContext to create and manage your database DbDatabase.SetInitializer(new CreateCeDatabaseIfNotExists<PersonContext>()); } } Now our database and entity framework are set up, so we can expose data via WCF Data Services. Note: This is a bare-bones implementation with no administration screens. If you'd like to see how those are added, check out The Full Stack screencast series. Creating the oData Service using WCF Data Services Add a new WCF Data Service to the project (right-click the project / Add New Item / Web / WCF Data Service). We’ll be exposing all the data as read/write. Remember to reconfigure to control and minimize access as appropriate for your own application. Open the code behind for your service. In our case, the service was called PersonTestDataService.svc so the code behind class file is PersonTestDataService.svc.cs. using System.Data.Services; using System.Data.Services.Common; using System.ServiceModel; using DeadSimpleServer.Models; namespace DeadSimpleServer { [ServiceBehavior( IncludeExceptionDetailInFaults = true )] public class PersonTestDataService : DataService<PersonContext> { // This method is called only once to initialize service-wide policies. public static void InitializeService( DataServiceConfiguration config ) { config.SetEntitySetAccessRule( "*", EntitySetRights.All ); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; config.UseVerboseErrors = true; } } } We're enabling a few additional settings to make it easier to debug if you run into trouble. The ServiceBehavior attribute is set to include exception details in faults, and we're using verbose errors. You can remove both of these when your service is working, as your public production service shouldn't be revealing exception information. You can view the output of the service by running the application and browsing to http://localhost:[portnumber]/PersonTestDataService.svc/: <service xml:base="http://localhost:49786/PersonTestDataService.svc/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:app="http://www.w3.org/2007/app" xmlns="http://www.w3.org/2007/app"> <workspace> <atom:title>Default</atom:title> <collection href="People"> <atom:title>People</atom:title> </collection> </workspace> </service> This indicates that the service exposes one collection, which is accessible by browsing to http://localhost:[portnumber]/PersonTestDataService.svc/People <?xml version="1.0" encoding="iso-8859-1" standalone="yes"?> <feed xml:base=http://localhost:49786/PersonTestDataService.svc/ xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns="http://www.w3.org/2005/Atom"> <title type="text">People</title> <id>http://localhost:49786/PersonTestDataService.svc/People</id> <updated>2010-12-29T01:01:50Z</updated> <link rel="self" title="People" href="People" /> <entry> <id>http://localhost:49786/PersonTestDataService.svc/People(1)</id> <title type="text"></title> <updated>2010-12-29T01:01:50Z</updated> <author> <name /> </author> <link rel="edit" title="Person" href="People(1)" /> <category term="DeadSimpleServer.Models.Person" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> <content type="application/xml"> <m:properties> <d:ID m:type="Edm.Int32">1</d:ID> <d:Name>George Washington</d:Name> </m:properties> </content> </entry> <entry> ... </entry> </feed> Let's recap what we've done so far. But enough with services and XML - let's get this into our Windows Phone client application. Creating the DataServiceContext for the Client Use the latest DataSvcUtil.exe from http://odata.codeplex.com. As of today, that's in this download: http://odata.codeplex.com/releases/view/54698 You need to run it with a few options: /uri - This will point to the service URI. In this case, it's http://localhost:59342/PersonTestDataService.svc Pick up the port number from your running server (e.g., the server formerly known as Cassini). /out - This is the DataServiceContext class that will be generated. You can name it whatever you'd like. /Version - should be set to 2.0 /DataServiceCollection - Include this flag to generate collections derived from the DataServiceCollection base, which brings in all the ObservableCollection goodness that handles your INotifyPropertyChanged events for you. Here's the console session from when we ran it: <ListBox x:Name="MainListBox" Margin="0,0,-12,0" ItemsSource="{Binding}" SelectionChanged="MainListBox_SelectionChanged"> Next, to keep things simple, change the Binding on the two TextBlocks within the DataTemplate to Name and ID, <ListBox x:Name="MainListBox" Margin="0,0,-12,0" ItemsSource="{Binding}" SelectionChanged="MainListBox_SelectionChanged"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Margin="0,0,0,17" Width="432"> <TextBlock Text="{Binding Name}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" /> <TextBlock Text="{Binding ID}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}" /> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> Getting The Context In the code-behind you’ll first declare a member variable to hold the context from the Entity Framework. This is named using convention over configuration. The db type is Person and the context is of type PersonContext, You initialize it by providing the URI, in this case using the URL obtained from the Cassini web server, PersonContext context = new PersonContext( new Uri( "http://localhost:49786/PersonTestDataService.svc/" ) ); Create a second member variable of type DataServiceCollection<Person> but do not initialize it, DataServiceCollection<Person> people; In the constructor you’ll initialize the DataServiceCollection using the PersonContext, public MainPage() { InitializeComponent(); people = new DataServiceCollection<Person>( context ); Finally, you’ll load the people collection using the LoadAsync method, passing in the fully specified URI for the People collection in the web service, people.LoadAsync( new Uri( "http://localhost:49786/PersonTestDataService.svc/People" ) ); Note that this method runs asynchronously and when it is finished the people collection is already populated. Thus, since we didn’t need or want to override any of the behavior we don’t implement the LoadCompleted. You can use the LoadCompleted event if you need to do any other UI updates, but you don't need to. The final code is as shown below: using System; using System.Data.Services.Client; using System.Windows; using System.Windows.Controls; using DeadSimpleServer.Models; using Microsoft.Phone.Controls; namespace WindowsPhoneODataTest { public partial class MainPage : PhoneApplicationPage { PersonContext context = new PersonContext( new Uri( "http://localhost:49786/PersonTestDataService.svc/" ) ); DataServiceCollection<Person> people; // Constructor public MainPage() { InitializeComponent(); // Set the data context of the listbox control to the sample data // DataContext = App.ViewModel; people = new DataServiceCollection<Person>( context ); people.LoadAsync( new Uri( "http://localhost:49786/PersonTestDataService.svc/People" ) ); DataContext = people; this.Loaded += new RoutedEventHandler( MainPage_Loaded ); } // Handle selection changed on ListBox private void MainListBox_SelectionChanged( object sender, SelectionChangedEventArgs e ) { // If selected index is -1 (no selection) do nothing if ( MainListBox.SelectedIndex == -1 ) return; // Navigate to the new page NavigationService.Navigate( new Uri( "/DetailsPage.xaml?selectedItem=" + MainListBox.SelectedIndex, UriKind.Relative ) ); // Reset selected index to -1 (no selection) MainListBox.SelectedIndex = -1; } // Load data for the ViewModel Items private void MainPage_Loaded( object sender, RoutedEventArgs e ) { if ( !App.ViewModel.IsDataLoaded ) { App.ViewModel.LoadData(); } } } } With people populated we can set it as the DataContext and run the application; you’ll find that the Name and ID are displayed in the list on the Mainpage. Here's how the pieces in the client fit together: Complete source code available here

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WPF ListView as a DataGrid – Part 3

- by psheriff

I have had a lot of great feedback on the blog post about turning the ListView into a DataGrid by creating GridViewColumn objects on the fly. So, in the last 2 parts, I showed a couple of different methods for accomplishing this. Let’s now look at one more and that is use Reflection to extract the properties from a Product, Customer, or Employee object to create the columns. Yes, Reflection is a slower approach, but you could create the columns one time then cache the View object for re-use. Another potential drawback is you may have columns in your object that you do not wish to display on your ListView. But, just because so many people asked, here is how to accomplish this using Reflection. Figure 1: Use Reflection to create GridViewColumns. Using Reflection to gather property names is actually quite simple. First you need to pass any type (Product, Customer, Employee, etc.) to a method like I did in my last two blog posts on this subject. Below is the method that I created in the WPFListViewCommon class that now uses reflection. C#public static GridView CreateGridViewColumns(Type anyType){ // Create the GridView GridView gv = new GridView(); GridViewColumn gvc; // Get the public properties. PropertyInfo[] propInfo = anyType.GetProperties(BindingFlags.Public | BindingFlags.Instance); foreach (PropertyInfo item in propInfo) { gvc = new GridViewColumn(); gvc.DisplayMemberBinding = new Binding(item.Name); gvc.Header = item.Name; gvc.Width = Double.NaN; gv.Columns.Add(gvc); } return gv;} VB.NETPublic Shared Function CreateGridViewColumns( _ ByVal anyType As Type) As GridView ' Create the GridView Dim gv As New GridView() Dim gvc As GridViewColumn ' Get the public properties. Dim propInfo As PropertyInfo() = _ anyType.GetProperties(BindingFlags.Public Or _ BindingFlags.Instance) For Each item As PropertyInfo In propInfo gvc = New GridViewColumn() gvc.DisplayMemberBinding = New Binding(item.Name) gvc.Header = item.Name gvc.Width = [Double].NaN gv.Columns.Add(gvc) Next Return gvEnd Function The key to using Relection is using the GetProperties method on the type you pass in. When you pass in a Product object as Type, you can now use the GetProperties method and specify, via flags, which properties you wish to return. In the code that I wrote, I am just retrieving the Public properties and only those that are Instance properties. I do not want any static/Shared properties or private properties. GetProperties returns an array of PropertyInfo objects. You can loop through this array and build your GridViewColumn objects by reading the Name property from the PropertyInfo object. Build the Product Screen To populate the ListView shown in Figure 1, you might write code like the following: C#private void CollectionSample(){ Product prod = new Product(); // Setup the GridView Columns lstData.View = WPFListViewCommon.CreateGridViewColumns(typeOf(Product)); lstData.DataContext = prod.GetProducts();} VB.NETPrivate Sub CollectionSample() Dim prod As New Product() ' Setup the GridView Columns lstData.View = WPFListViewCommon.CreateGridViewColumns( _ GetType(Product)) lstData.DataContext = prod.GetProducts()End Sub All you need to do now is to pass in a Type object from your Product class that you can get by using the typeOf() function in C# or the GetType() function in VB. That’s all there is to it! Summary There are so many different ways to approach the same problem in programming. That is what makes programming so much fun! In this blog post I showed you how to create ListView columns on the fly using Reflection. This gives you a lot of flexibility without having to write extra code as was done previously. NOTE: You can download the complete sample code (in both VB and C#) at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "WPF ListView as a DataGrid – Part 3" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".

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Quickly and Easily Create Folders in Windows By Dragging and Dropping Files

- by Lori Kaufman

If you use iOS or Android devices, you’re familiar with the drag-and-drop method of creating folders. If you like that method of grouping files, you can get the same functionality on your Windows PC using a free utility, called Smart Folders. Smart Folders helps you quickly organize your files, such as images, documents, and audio files, without having to create separate folders before you move the files. Simply drag one file on top of another file to create a new folder. To use Smart Folders to easily create folders, double-click on the .exe file you downloaded (see the link at the end of this article). Why Does 64-Bit Windows Need a Separate “Program Files (x86)” Folder? Why Your Android Phone Isn’t Getting Operating System Updates and What You Can Do About It How To Delete, Move, or Rename Locked Files in Windows

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Internationalize WebCenter Portal - Content Presenter

- by Stefan Krantz

Lately we have been involved in engagements where internationalization has been holding the project back from success. In this post we are going to explain how to get Content Presenter and its editorials to comply with the current selected locale for the WebCenter Portal session. As you probably know by now WebCenter Portal leverages the Localization support from Java Server Faces (JSF), in this post we will assume that the localization is controlled and enforced by switching the current browsers locale between English and Spanish. There is two main scenarios in internationalization of a content enabled pages, since Content Presenter offers both presentation of information as well as contribution of information, in this post we will look at how to enable seamless integration of correct localized version of the back end content file and how to enable the editor/author to edit the correct localized version of the file based on the current browser locale. Solution Scenario 1 - Localization aware content presentation Due to the amount of steps required to implement the enclosed solution proposal I have decided to share the solution with you in group components for each facet of the solution. If you want to get more details on each step, you can review the enclosed components. This post will guide you through the steps of enabling each component and what it enables/changes in each section of the system. Enable Content Presenter Customization By leveraging a predictable naming convention of the data files used to hold the content for the Content Presenter instance we can easily develop a component that will dynamically switch the name out before presenting the information. The naming convention we have leverage is the industry best practice by having a shared identifier as prefix (ContentABC) and a language enabled suffix (_EN) (_ES). So the assumption is that each file pair in above example should look like following:- English version - (ContentABC_EN)- Spanish version - (ContentABC_ES) Based on above theory we can now easily regardless of the primary version assigned to the content presenter instance switch the language out by using the localization support from JSF. Below java bean (oracle.webcenter.doclib.internal.view.presenter.NLSHelperBean) is enclosed in the customization project available for download at the bottom of the post: 1: public static final String CP_D_DOCNAME_FORMAT = "%s_%s"; 2: public static final int CP_UNIQUE_ID_INDEX = 0; 3: private ContentPresenter presenter = null; 4: 5: 6: public NLSHelperBean() { 7: super(); 8: } 9: 10: /** 11: * This method updates the configuration for the pageFlowScope to have the correct datafile 12: * for the current Locale 13: */ 14: public void initLocaleForDataFile() { 15: String dataFile = null; 16: // Checking that state of presenter is present, also make sure the item is eligible for localization by locating the "_" in the name 17: if(presenter.getConfiguration().getDatasource() != null && 18: presenter.getConfiguration().getDatasource().isNodeDatasource() && 19: presenter.getConfiguration().getDatasource().getNodeIdDatasource() != null && 20: !presenter.getConfiguration().getDatasource().getNodeIdDatasource().equals("") && 21: presenter.getConfiguration().getDatasource().getNodeIdDatasource().indexOf("_") > 0) { 22: dataFile = presenter.getConfiguration().getDatasource().getNodeIdDatasource(); 23: FacesContext fc = FacesContext.getCurrentInstance(); 24: //Leveraging the current faces contenxt to get current localization language 25: String currentLocale = fc.getViewRoot().getLocale().getLanguage().toUpperCase(); 26: String newDataFile = dataFile; 27: String [] uniqueIdArr = dataFile.split("_"); 28: if(uniqueIdArr.length > 0) { 29: newDataFile = String.format(CP_D_DOCNAME_FORMAT, uniqueIdArr[CP_UNIQUE_ID_INDEX], currentLocale); 30: } 31: //Replacing the current Node datasource with localized datafile. 32: presenter.getConfiguration().getDatasource().setNodeIdDatasource(newDataFile); 33: } 34: } With this bean code available to our WebCenter Portal implementation we can start the next step, by overriding the standard behavior in content presenter by applying a MDS Taskflow customization to the content presenter taskflow, following taskflow customization has been applied to the customization project attached to this post:- Library: WebCenter Document Library Service View- Path: oracle.webcenter.doclib.view.jsf.taskflows.presenter- File: contentPresenter.xml Changes made in above customization view:1. A new method invocation activity has been added (initLocaleForDataFile)2. The method invocation invokes the new NLSHelperBean3. The default activity is moved to the new Method invocation (initLocaleForDataFile)4. The outcome from the method invocation goes to determine-navigation (original default activity) The above changes concludes the presentation modification to support a compatible localization scenario for a content driven page. In addition this customization do not limit or disables the out of the box capabilities of WebCenter Portal. Steps to enable above customization Start JDeveloper and open your WebCenter Portal Application Select "Open Project" and include the extracted project you downloaded (CPNLSCustomizations.zip) Make sure the build out put from CPNLSCustomizations project is a dependency to your Portal project Deploy your Portal Application to your WC_CustomPortal managed server Make sure your naming convention of the two data files follow above recommendation Example result of the solution: Solution Scenario 2 - Localization aware content creation and authoring As you could see from Solution Scenario 1 we require the naming convention to be strictly followed, this means in the hands of a user with limited technology knowledge this can be one of the failing links in this solutions. Therefore I strongly recommend that you also follow this part since this will eliminate this risk and also increase the editors/authors usability with a magnitude. The current WebCenter Portal Architecture leverages WebCenter Content today to maintain, publish and manage content, therefore we need to make few efforts in making sure this part of the architecture is on board with our new naming practice and also simplifies the creation of content for our end users. As you probably remember the naming convention required a prefix to be common so I propose we enable a new component that help you auto name the content items dDocName (this means that the readable title can still be in a human readable format). The new component (WCP-LocalizationSupport.zip) built for this scenario will enable a couple of things: 1. A new service where a sequential number can be generate on request - service name: GET_WCP_LOCALE_CONTENTID 2. The content presenter is leveraging a specific function when launching the content creation wizard from within Content Presenter. Assumption is that users will create the content by clicking "Create Web Content" button. When clicking the button the wizard opened is actually running in side of WebCenter Content server, file executed (contentwizard.hcsp). This file uses JSON commands that will generate operations in the content server, I have extend this file to create two identical data files instead of one.- First it creates the English version by leveraging the new Service and a Global Rule to set the dDocName on the original check in screen, this global rule is available in a configuration package attached to this blog (NLSContentProfileRule.zip)- Secondly we run a set of JSON javascripts to create the Spanish version with the same details except for the name where we replace the suffix with (_ES)- Then content creation wizard ends with its out of the box behavior and assigns the Content Presenter instance the English versionSee Javascript markup below - this can be changed in the (WCP-LocalizationSupport.zip/component/WCP-LocalizationSupport/publish/webcenter) 1: //---------------------------------------A-TEAM--------------------------------------- 2: WCM.ContentWizard.CheckinContentPage.OnCheckinComplete = function(returnParams) 3: { 4: var callback = WCM.ContentWizard.CheckinContentPage.checkinCompleteCallback; 5: WCM.ContentWizard.ChooseContentPage.OnSelectionComplete(returnParams, callback); 6: // Load latest DOC_INFO_SIMPLE 7: var cgiPath = DOCLIB.config.httpCgiPath; 8: var jsonBinder = new WCM.Idc.JSONBinder(); 9: jsonBinder.SetLocalDataValue('IdcService', 'DOC_INFO_SIMPLE'); 10: jsonBinder.SetLocalDataValue('dID', returnParams.dID); 11: jsonBinder.Send(cgiPath, $CB(this, function(http) { 12: var ret = http.GetResponseText(); 13: var binder = new WCM.Idc.JSONBinder(ret); 14: var dDocName = binder.GetResultSetValue('DOC_INFO', 'dDocName', 0); 15: if(dDocName.indexOf("_") > 0){ 16: var ssBinder = new WCM.Idc.JSONBinder(); 17: ssBinder.SetLocalDataValue('IdcService', 'SS_CHECKIN_NEW'); 18: //Additional Localization dDocName generated 19: ssBinder.SetLocalDataValue('dDocName', getLocalizedDocName(dDocName, "es")); 20: ssBinder.SetLocalDataValue('primaryFile', 'default.xml'); 21: ssBinder.SetLocalDataValue('ssDefaultDocumentToken', 'SSContributorDataFile'); 22: 23: for(var n = 0 ; n < binder.GetResultSetFields('DOC_INFO').length ; n++) { 24: var field = binder.GetResultSetFields('DOC_INFO')[n]; 25: if(field != 'dID' && 26: field != 'dDocName' && 27: field != 'dID' && 28: field != 'dReleaseState' && 29: field != 'dRevClassID' && 30: field != 'dRevisionID' && 31: field != 'dRevLabel') { 32: ssBinder.SetLocalDataValue(field, binder.GetResultSetValue('DOC_INFO', field, 0)); 33: } 34: } 35: ssBinder.Send(cgiPath, $CB(this, function(http) {})); 36: } 37: })); 38: } 39: 40: //Support function to create localized dDocNames 41: function getLocalizedDocName(dDocName, lang) { 42: var result = dDocName.replace("_EN", ("_" + lang)); 43: return result; 44: } 45: //---------------------------------------A-TEAM--------------------------------------- 3. By applying the enclosed NLSContentProfileRule.zip, the check in screen for DataFile creation will have auto naming enabled with localization suffix (default is English)You can change the default language by updating the GlobalNlsRule and assign preferred prefix.See Rule markup for dDocName field below: <$executeService("GET_WCP_LOCALE_CONTENTID")$><$dprDefaultValue=WCP_LOCALE.LocaleContentId & "_EN"$> Steps to enable above extensions and configurations Install WebCenter Component (WCP-LocalizationSupport.zip), via the AdminServer in WebCenter Content Administration menus Enable the component and restart the content server Apply the configuration bundle to enable the new Global Rule (GlobalNlsRule), via the WebCenter Content Administration/Config Migration Admin New Content Creation Experience Result Content EditingContent editing will by default be enabled for authoring in the current select locale since the content file is selected by (Solution Scenario 1), this means that a user can switch his browser locale and then get the editing experience adaptable to the current selected locale. NotesA-Team are planning to post a solution on how to inline switch the locale of the WebCenter Portal Session, so the Content Presenter, Navigation Model and other Face related features are localized accordingly. Content Presenter examples used in this post is an extension to following post:https://blogs.oracle.com/ATEAM_WEBCENTER/entry/enable_content_editing_of_iterative Downloads CPNLSCustomizations.zip - WebCenter Portal, Content Presenter Customization https://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/CPNLSCustomizations.zip WCP-LocalizationSupport.zip - WebCenter Content, Extension Component to enable localization creation of files with compliant auto naminghttps://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/WCP-LocalizationSupport.zip NLSContentProfileRule.zip - WebCenter Content, Configuration Update Bundle to enable Global rule for new check in naming of data fileshttps://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/NLSContentProfileRule.zip

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Transactional Messaging in the Windows Azure Service Bus

- by Alan Smith

Introduction I’m currently working on broadening the content in the Windows Azure Service Bus Developer Guide. One of the features I have been looking at over the past week is the support for transactional messaging. When using the direct programming model and the WCF interface some, but not all, messaging operations can participate in transactions. This allows developers to improve the reliability of messaging systems. There are some limitations in the transactional model, transactions can only include one top level messaging entity (such as a queue or topic, subscriptions are no top level entities), and transactions cannot include other systems, such as databases. As the transaction model is currently not well documented I have had to figure out how things work through experimentation, with some help from the development team to confirm any questions I had. Hopefully I’ve got the content mostly correct, I will update the content in the e-book if I find any errors or improvements that can be made (any feedback would be very welcome). I’ve not had a chance to look into the code for transactions and asynchronous operations, maybe that would make a nice challenge lab for my Windows Azure Service Bus course. Transactional Messaging Messaging entities in the Windows Azure Service Bus provide support for participation in transactions. This allows developers to perform several messaging operations within a transactional scope, and ensure that all the actions are committed or, if there is a failure, none of the actions are committed. There are a number of scenarios where the use of transactions can increase the reliability of messaging systems. Using TransactionScope In .NET the TransactionScope class can be used to perform a series of actions in a transaction. The using declaration is typically used de define the scope of the transaction. Any transactional operations that are contained within the scope can be committed by calling the Complete method. If the Complete method is not called, any transactional methods in the scope will not commit. // Create a transactional scope. using (TransactionScope scope = new TransactionScope()) { // Do something. // Do something else. // Commit the transaction. scope.Complete(); } In order for methods to participate in the transaction, they must provide support for transactional operations. Database and message queue operations typically provide support for transactions. Transactions in Brokered Messaging Transaction support in Service Bus Brokered Messaging allows message operations to be performed within a transactional scope; however there are some limitations around what operations can be performed within the transaction. In the current release, only one top level messaging entity, such as a queue or topic can participate in a transaction, and the transaction cannot include any other transaction resource managers, making transactions spanning a messaging entity and a database not possible. When sending messages, the send operations can participate in a transaction allowing multiple messages to be sent within a transactional scope. This allows for “all or nothing” delivery of a series of messages to a single queue or topic. When receiving messages, messages that are received in the peek-lock receive mode can be completed, deadlettered or deferred within a transactional scope. In the current release the Abandon method will not participate in a transaction. The same restrictions of only one top level messaging entity applies here, so the Complete method can be called transitionally on messages received from the same queue, or messages received from one or more subscriptions in the same topic. Sending Multiple Messages in a Transaction A transactional scope can be used to send multiple messages to a queue or topic. This will ensure that all the messages will be enqueued or, if the transaction fails to commit, no messages will be enqueued. An example of the code used to send 10 messages to a queue as a single transaction from a console application is shown below. QueueClient queueClient = messagingFactory.CreateQueueClient(Queue1); Console.Write("Sending"); // Create a transaction scope. using (TransactionScope scope = new TransactionScope()) { for (int i = 0; i < 10; i++) { // Send a message BrokeredMessage msg = new BrokeredMessage("Message: " + i); queueClient.Send(msg); Console.Write("."); } Console.WriteLine("Done!"); Console.WriteLine(); // Should we commit the transaction? Console.WriteLine("Commit send 10 messages? (yes or no)"); string reply = Console.ReadLine(); if (reply.ToLower().Equals("yes")) { // Commit the transaction. scope.Complete(); } } Console.WriteLine(); messagingFactory.Close(); The transaction scope is used to wrap the sending of 10 messages. Once the messages have been sent the user has the option to either commit the transaction or abandon the transaction. If the user enters “yes”, the Complete method is called on the scope, which will commit the transaction and result in the messages being enqueued. If the user enters anything other than “yes”, the transaction will not commit, and the messages will not be enqueued. Receiving Multiple Messages in a Transaction The receiving of multiple messages is another scenario where the use of transactions can improve reliability. When receiving a group of messages that are related together, maybe in the same message session, it is possible to receive the messages in the peek-lock receive mode, and then complete, defer, or deadletter the messages in one transaction. (In the current version of Service Bus, abandon is not transactional.) The following code shows how this can be achieved. using (TransactionScope scope = new TransactionScope()) { while (true) { // Receive a message. BrokeredMessage msg = q1Client.Receive(TimeSpan.FromSeconds(1)); if (msg != null) { // Wrote message body and complete message. string text = msg.GetBody<string>(); Console.WriteLine("Received: " + text); msg.Complete(); } else { break; } } Console.WriteLine(); // Should we commit? Console.WriteLine("Commit receive? (yes or no)"); string reply = Console.ReadLine(); if (reply.ToLower().Equals("yes")) { // Commit the transaction. scope.Complete(); } Console.WriteLine(); } Note that if there are a large number of messages to be received, there will be a chance that the transaction may time out before it can be committed. It is possible to specify a longer timeout when the transaction is created, but It may be better to receive and commit smaller amounts of messages within the transaction. It is also possible to complete, defer, or deadletter messages received from more than one subscription, as long as all the subscriptions are contained in the same topic. As subscriptions are not top level messaging entities this scenarios will work. The following code shows how this can be achieved. try { using (TransactionScope scope = new TransactionScope()) { // Receive one message from each subscription. BrokeredMessage msg1 = subscriptionClient1.Receive(); BrokeredMessage msg2 = subscriptionClient2.Receive(); // Complete the message receives. msg1.Complete(); msg2.Complete(); Console.WriteLine("Msg1: " + msg1.GetBody<string>()); Console.WriteLine("Msg2: " + msg2.GetBody<string>()); // Commit the transaction. scope.Complete(); } } catch (Exception ex) { Console.WriteLine(ex.Message); } Unsupported Scenarios The restriction of only one top level messaging entity being able to participate in a transaction makes some useful scenarios unsupported. As the Windows Azure Service Bus is under continuous development and new releases are expected to be frequent it is possible that this restriction may not be present in future releases. The first is the scenario where messages are to be routed to two different systems. The following code attempts to do this. try { // Create a transaction scope. using (TransactionScope scope = new TransactionScope()) { BrokeredMessage msg1 = new BrokeredMessage("Message1"); BrokeredMessage msg2 = new BrokeredMessage("Message2"); // Send a message to Queue1 Console.WriteLine("Sending Message1"); queue1Client.Send(msg1); // Send a message to Queue2 Console.WriteLine("Sending Message2"); queue2Client.Send(msg2); // Commit the transaction. Console.WriteLine("Committing transaction..."); scope.Complete(); } } catch (Exception ex) { Console.WriteLine(ex.Message); } The results of running the code are shown below. When attempting to send a message to the second queue the following exception is thrown: No active Transaction was found for ID '35ad2495-ee8a-4956-bbad-eb4fedf4a96e:1'. The Transaction may have timed out or attempted to span multiple top-level entities such as Queue or Topic. The server Transaction timeout is: 00:01:00..TrackingId:947b8c4b-7754-4044-b91b-4a959c3f9192_3_3,TimeStamp:3/29/2012 7:47:32 AM. Another scenario where transactional support could be useful is when forwarding messages from one queue to another queue. This would also involve more than one top level messaging entity, and is therefore not supported. Another scenario that developers may wish to implement is performing transactions across messaging entities and other transactional systems, such as an on-premise database. In the current release this is not supported. Workarounds for Unsupported Scenarios There are some techniques that developers can use to work around the one top level entity limitation of transactions. When sending two messages to two systems, topics and subscriptions can be used. If the same message is to be sent to two destinations then the subscriptions would have the default subscriptions, and the client would only send one message. If two different messages are to be sent, then filters on the subscriptions can route the messages to the appropriate destination. The client can then send the two messages to the topic in the same transaction. In scenarios where a message needs to be received and then forwarded to another system within the same transaction topics and subscriptions can also be used. A message can be received from a subscription, and then sent to a topic within the same transaction. As a topic is a top level messaging entity, and a subscription is not, this scenario will work.

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C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

- by James Michael Hare

Once again we consider some of the lesser known classes and keywords of C#. In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>. Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>. Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework. And out of this framework emerged the System.Collections namespace, and it was good. It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections. The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever! With generics the C# language finally got an equivalent of the very powerful C++ templates. As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections. The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on. The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well. So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them. The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required. Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11: 12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20: 21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner. Looking at today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes. With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe. This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations. Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5: 6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9: 10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17: 18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock. With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level). So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently! For example, what if you have a Dictionary that has frequent reads but in-frequent updates? Do you want to lock down the entire Dictionary for every access? This would be overkill and would prevent concurrent reads. In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell). This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in. The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null. Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to. Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic. For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty! This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models. I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts. Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration). Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container. If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations. This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2: 3: // adding to stack is much the same as before 4: stack.Push("First"); 5: 6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek(). This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed. Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items. Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6: 7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10: 11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call. That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call. This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2: 3: // adding to stack is much the same as before 4: stack.Push("First"); 5: 6: var results = stack.GetEnumerator(); 7: 8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10: 11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct. You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all. In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class. The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays. Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart. Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count. This results overall in a O(1) complexity which is quite good. It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2: 3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue. There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue(). Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results. Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2: 3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: 6: var iterator = queue.GetEnumerator(); 7: 8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10: 11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious. Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation. This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5: 6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12: 13: results.Enqueue(result); 14: }); 15: 16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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Updating the managed debugging API for .NET v4

- by Brian Donahue

In any successful investigation, the right tools play a big part in collecting evidence about the state of the "crime scene" as it was before the detectives arrived. Unfortunately for the Crash Scene Investigator, we don't have the budget to fly out to the customer's site, chalk the outline, and eat their doughnuts. We have to rely on the end-user to collect the evidence for us, which means giving them the fingerprint dust and the evidence baggies and leaving them to it. With that in mind, the Red Gate support team have been writing tools that can collect vital clues with a minimum of fuss. Years ago we would have asked for a memory dump, where we used to get the customer to run CDB.exe and produce dumps that we could analyze in-house, but those dumps were pretty unwieldy (500MB files) and the debugger often didn't dump exactly where we wanted, or made five or more dumps. What we wanted was just the minimum state information from the program at the time of failure, so we produced a managed debugger that captured every first and second-chance exception and logged the stack and a minimal amount of variables from the memory of the application, which could all be exported as XML. This caused less inconvenience to the end-user because it is much easier to send a 65KB XML file in an email than a 500MB file containing all of the application's memory. We don't need to have the entire victim shipped out to us when we just want to know what was under the fingernails. The thing that made creating a managed debugging tool possible was the MDbg Engine example written by Microsoft as part of the Debugging Tools for Windows distribution. Since the ICorDebug interface is a bit difficult to understand, they had kindly created some wrappers that provided an event-driven debugging model that was perfect for our needs, but .NET 4 applications under debugging started complaining that "The debugger's protocol is incompatible with the debuggee". The introduction of .NET Framework v4 had changed the managed debugging API significantly, however, without an update for the MDbg Engine code! After a few hours of research, I had finally worked out that most of the version 4 ICorDebug interface still works much the same way in "legacy" v2 mode and there was a relatively easy fix for the problem in that you can still get a reference to legacy ICorDebug by changing the way the interface is created. In .NET v2, the interface was acquired using the CreateDebuggingInterfaceFromVersion method in mscoree.dll. In v4, you must first create IClrMetaHost, enumerate the runtimes, get an ICLRRuntimeInfo interface to the .NET 4 runtime from that, and use the GetInterface method in mscoree.dll to return a "legacy" ICorDebug interface. The rest of the MDbg Engine will continue working the old way. Here is how I had changed the MDbg Engine code to support .NET v4: private void InitFromVersion(string debuggerVersion){if( debuggerVersion.StartsWith("v1") ){throw new ArgumentException( "Can't debug a version 1 CLR process (\"" + debuggerVersion + "\"). Run application in a version 2 CLR, or use a version 1 debugger instead." );} ICorDebug rawDebuggingAPI=null;if (debuggerVersion.StartsWith("v4")){Guid CLSID_MetaHost = new Guid("9280188D-0E8E-4867-B30C-7FA83884E8DE"); Guid IID_MetaHost = new Guid("D332DB9E-B9B3-4125-8207-A14884F53216"); ICLRMetaHost metahost = (ICLRMetaHost)NativeMethods.ClrCreateInterface(CLSID_MetaHost, IID_MetaHost); IEnumUnknown runtimes = metahost.EnumerateInstalledRuntimes(); ICLRRuntimeInfo runtime = GetRuntime(runtimes, debuggerVersion); //Defined in metahost.hGuid CLSID_CLRDebuggingLegacy = new Guid(0xDF8395B5, 0xA4BA, 0x450b, 0xA7, 0x7C, 0xA9, 0xA4, 0x77, 0x62, 0xC5, 0x20);Guid IID_ICorDebug = new Guid("3D6F5F61-7538-11D3-8D5B-00104B35E7EF"); Object res;runtime.GetInterface(ref CLSID_CLRDebuggingLegacy, ref IID_ICorDebug, out res); rawDebuggingAPI = (ICorDebug)res; }elserawDebuggingAPI = NativeMethods.CreateDebuggingInterfaceFromVersion((int)CorDebuggerVersion.Whidbey,debuggerVersion);if (rawDebuggingAPI != null)InitFromICorDebug(rawDebuggingAPI);elsethrow new ArgumentException("Support for debugging version " + debuggerVersion + " is not yet implemented");} The changes above will ensure that the debugger can support .NET Framework v2 and v4 applications with the same codebase, but we do compile two different applications: one targeting v2 and the other v4. As a footnote I need to add that some missing native methods and wrappers, along with the EnumerateRuntimes method code, came from the Mindbg project on Codeplex. Another change is that when using the MDbgEngine.CreateProcess to launch a process in the debugger, do not supply a null as the final argument. This does not work any more because GetCORVersion always returns "v2.0.50727" as the function has been deprecated in .NET v4. What's worse is that on a system with only .NET 4, the user will be prompted to download and install .NET v2! Not nice! This works much better: proc = m_Debugger.CreateProcess(ProcessName, ProcessArgs, DebugModeFlag.Default,String.Format("v{0}.{1}.{2}",System.Environment.Version.Major,System.Environment.Version.Minor,System.Environment.Version.Build)); Microsoft "unofficially" plan on updating the MDbg samples soon, but if you have an MDbg-based application, you can get it working right now by changing one method a bit and adding a few new interfaces (ICLRMetaHost, IEnumUnknown, and ICLRRuntimeInfo). The new, non-legacy implementation of MDbg Engine will add new, interesting features like dump-file support and by association I assume garbage-collection/managed object stats, so it will be well worth looking into if you want to extend the functionality of a managed debugger going forward.

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ASP.NET MVC 3 Release Candidate 2 Released

- by shiju

Microsoft has shipped Release Candidate version 2 for ASP.NET MVC 3. You can download the ASP.NET MVC 3 Release Candidate 2 from here . If you have installed Visual Studio Service Pack 1 Beta, you must install ASP.NET MVC 3 RC 2. Otherwise it will break the IntelliSense feature in the Razor views of ASP.NET MVC 3 RC1. The following are the some of the new changes in ASP.NET MVC 3 RC 2. Added Html.Raw Method Renamed "Controller.ViewModel" Property and the "View" Property To "ViewBag" Renamed "ControllerSessionStateAttribute" Class to "SessionStateAttribute" Fixed "RenderAction" Method to Give Explicit Values Precedence During Model Binding You can read more details from ScottGu’s blog post Announcing ASP.NET MVC 3 (Release Candidate 2)

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User generated articles, how to do meta description?

- by Tom Gullen

If users submit a lot of good quality articles on the site, what is the best way to approach the meta description tag? I see two options: Have a description box and rely on them to fill it sensibly and in a good quality way Just exclude the meta description Method 1 is bad initially, but I'm willing to put time in going through and editing/checking all of them on a permanent basis. Method 2 is employed by the stack exchange site, and lets the search bots extract the best part of the page in the SERP. Thoughts? Ideas? I'm thinking a badly formed description tag is more damaging than not having one at all at the end of the day. I don't expect content to ever become unwieldy and too much to manage.

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Console keyboard input OOP

- by Alexandre P. Levasseur

I am trying to build a very simple console-based game with a focus on using OOP instead of procedural programming because I intend to build up on that code for more complex projects. I am wondering if there is a design pattern that nicely handles this use case: There is a Player class with a MakeMove() method interacting with the board game. The MakeMove() method has to somehow get the user input yet I do not want to code it into the Player class as this would reduce cohesion and augment coupling. I was thinking of maybe having some controller class handle the sequence of events and thus the calls to keyboard input. However, that controller class would need to be able to handle differently the subclasses of Player (e.g. the AI class does not require keyboard input). Thoughts ?

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Using RIA DomainServices with ASP.NET and MVC 2

- by Bobby Diaz

Recently, I started working on a new ASP.NET MVC 2 project and I wanted to reuse the data access (LINQ to SQL) and business logic methods (WCF RIA Services) that had been developed for a previous project that used Silverlight for the front-end. I figured that I would be able to instantiate the various DomainService classes from within my controller’s action methods, because after all, the code for those services didn’t look very complicated. WRONG! I didn’t realize at first that some of the functionality is handled automatically by the framework when the domain services are hosted as WCF services. After some initial searching, I came across an invaluable post by Joe McBride, which described how to get RIA Service .svc files to work in an MVC 2 Web Application, and another by Brad Abrams. Unfortunately, Brad’s solution was for an earlier preview release of RIA Services and no longer works with the version that I am running (PDC Preview). I have not tried the RC version of WCF RIA Services, so I am not sure if any of the issues I am having have been resolved, but I wanted to come up with a way to reuse the shared libraries so I wouldn’t have to write a non-RIA version that basically did the same thing. The classes I came up with work with the scenarios I have encountered so far, but I wanted to go ahead and post the code in case someone else is having the same trouble I had. Hopefully this will save you a few headaches! 1. Querying When I first tried to use a DomainService class to perform a query inside one of my controller’s action methods, I got an error stating that “This DomainService has not been initialized.” To solve this issue, I created an extension method for all DomainServices that creates the required DomainServiceContext and passes it to the service’s Initialize() method. Here is the code for the extension method; notice that I am creating a sort of mock HttpContext for those cases when the service is running outside of IIS, such as during unit testing! public static class ServiceExtensions { /// <summary> /// Initializes the domain service by creating a new <see cref="DomainServiceContext"/> /// and calling the base DomainService.Initialize(DomainServiceContext) method. /// </summary> /// <typeparam name="TService">The type of the service.</typeparam> /// <param name="service">The service.</param> /// <returns></returns> public static TService Initialize<TService>(this TService service) where TService : DomainService { var context = CreateDomainServiceContext(); service.Initialize(context); return service; } private static DomainServiceContext CreateDomainServiceContext() { var provider = new ServiceProvider(new HttpContextWrapper(GetHttpContext())); return new DomainServiceContext(provider, DomainOperationType.Query); } private static HttpContext GetHttpContext() { var context = HttpContext.Current; #if DEBUG // create a mock HttpContext to use during unit testing... if ( context == null ) { var writer = new StringWriter(); var request = new SimpleWorkerRequest("/", "/", String.Empty, String.Empty, writer); context = new HttpContext(request) { User = new GenericPrincipal(new GenericIdentity("debug"), null) }; } #endif return context; } } With that in place, I can use it almost as normally as my first attempt, except with a call to Initialize(): public ActionResult Index() { var service = new NorthwindService().Initialize(); var customers = service.GetCustomers(); return View(customers); } 2. Insert / Update / Delete Once I got the records showing up, I was trying to insert new records or update existing data when I ran into the next issue. I say issue because I wasn’t getting any kind of error, which made it a little difficult to track down. But once I realized that that the DataContext.SubmitChanges() method gets called automatically at the end of each domain service submit operation, I could start working on a way to mimic the behavior of a hosted domain service. What I came up with, was a base class called LinqToSqlRepository<T> that basically sits between your implementation and the default LinqToSqlDomainService<T> class. [EnableClientAccess()] public class NorthwindService : LinqToSqlRepository<NorthwindDataContext> { public IQueryable<Customer> GetCustomers() { return this.DataContext.Customers; } public void InsertCustomer(Customer customer) { this.DataContext.Customers.InsertOnSubmit(customer); } public void UpdateCustomer(Customer currentCustomer) { this.DataContext.Customers.TryAttach(currentCustomer, this.ChangeSet.GetOriginal(currentCustomer)); } public void DeleteCustomer(Customer customer) { this.DataContext.Customers.TryAttach(customer); this.DataContext.Customers.DeleteOnSubmit(customer); } } Notice the new base class name (just change LinqToSqlDomainService to LinqToSqlRepository). I also added a couple of DataContext (for Table<T>) extension methods called TryAttach that will check to see if the supplied entity is already attached before attempting to attach it, which would cause an error! 3. LinqToSqlRepository<T> Below is the code for the LinqToSqlRepository class. The comments are pretty self explanatory, but be aware of the [IgnoreOperation] attributes on the generic repository methods, which ensures that they will be ignored by the code generator and not available in the Silverlight client application. /// <summary> /// Provides generic repository methods on top of the standard /// <see cref="LinqToSqlDomainService<TContext>"/> functionality. /// </summary> /// <typeparam name="TContext">The type of the context.</typeparam> public abstract class LinqToSqlRepository<TContext> : LinqToSqlDomainService<TContext> where TContext : System.Data.Linq.DataContext, new() { /// <summary> /// Retrieves an instance of an entity using it's unique identifier. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <param name="keyValues">The key values.</param> /// <returns></returns> [IgnoreOperation] public virtual TEntity GetById<TEntity>(params object[] keyValues) where TEntity : class { var table = this.DataContext.GetTable<TEntity>(); var mapping = this.DataContext.Mapping.GetTable(typeof(TEntity)); var keys = mapping.RowType.IdentityMembers .Select((m, i) => m.Name + " = @" + i) .ToArray(); return table.Where(String.Join(" && ", keys), keyValues).FirstOrDefault(); } /// <summary> /// Creates a new query that can be executed to retrieve a collection /// of entities from the <see cref="DataContext"/>. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <returns></returns> [IgnoreOperation] public virtual IQueryable<TEntity> GetEntityQuery<TEntity>() where TEntity : class { return this.DataContext.GetTable<TEntity>(); } /// <summary> /// Inserts the specified entity. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <param name="entity">The entity.</param> /// <returns></returns> [IgnoreOperation] public virtual bool Insert<TEntity>(TEntity entity) where TEntity : class { //var table = this.DataContext.GetTable<TEntity>(); //table.InsertOnSubmit(entity); return this.Submit(entity, null, DomainOperation.Insert); } /// <summary> /// Updates the specified entity. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <param name="entity">The entity.</param> /// <returns></returns> [IgnoreOperation] public virtual bool Update<TEntity>(TEntity entity) where TEntity : class { return this.Update(entity, null); } /// <summary> /// Updates the specified entity. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <param name="entity">The entity.</param> /// <param name="original">The original.</param> /// <returns></returns> [IgnoreOperation] public virtual bool Update<TEntity>(TEntity entity, TEntity original) where TEntity : class { if ( original == null ) { original = GetOriginal(entity); } var table = this.DataContext.GetTable<TEntity>(); table.TryAttach(entity, original); return this.Submit(entity, original, DomainOperation.Update); } /// <summary> /// Deletes the specified entity. /// </summary> /// <typeparam name="TEntity">The type of the entity.</typeparam> /// <param name="entity">The entity.</param> /// <returns></returns> [IgnoreOperation] public virtual bool Delete<TEntity>(TEntity entity) where TEntity : class { //var table = this.DataContext.GetTable<TEntity>(); //table.TryAttach(entity); //table.DeleteOnSubmit(entity); return this.Submit(entity, null, DomainOperation.Delete); } protected virtual bool Submit(Object entity, Object original, DomainOperation operation) { var entry = new ChangeSetEntry(0, entity, original, operation); var changes = new ChangeSet(new ChangeSetEntry[] { entry }); return base.Submit(changes); } private TEntity GetOriginal<TEntity>(TEntity entity) where TEntity : class { var context = CreateDataContext(); var table = context.GetTable<TEntity>(); return table.FirstOrDefault(e => e == entity); } } 4. Conclusion So there you have it, a fully functional Repository implementation for your RIA Domain Services that can be consumed by your ASP.NET and MVC applications. I have uploaded the source code along with unit tests and a sample web application that queries the Customers table from inside a Controller, as well as a Silverlight usage example. As always, I welcome any comments or suggestions on the approach I have taken. If there is enough interest, I plan on contacting Colin Blair or maybe even the man himself, Brad Abrams, to see if this is something worthy of inclusion in the WCF RIA Services Contrib project. What do you think? Enjoy!

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Basic Spatial Data with SQL Server and Entity Framework 5.0

- by Rick Strahl

In my most recent project we needed to do a bit of geo-spatial referencing. While spatial features have been in SQL Server for a while using those features inside of .NET applications hasn't been as straight forward as could be, because .NET natively doesn't support spatial types. There are workarounds for this with a few custom project like SharpMap or a hack using the Sql Server specific Geo types found in the Microsoft.SqlTypes assembly that ships with SQL server. While these approaches work for manipulating spatial data from .NET code, they didn't work with database access if you're using Entity Framework. Other ORM vendors have been rolling their own versions of spatial integration. In Entity Framework 5.0 running on .NET 4.5 the Microsoft ORM finally adds support for spatial types as well. In this post I'll describe basic geography features that deal with single location and distance calculations which is probably the most common usage scenario. SQL Server Transact-SQL Syntax for Spatial Data Before we look at how things work with Entity framework, lets take a look at how SQL Server allows you to use spatial data to get an understanding of the underlying semantics. The following SQL examples should work with SQL 2008 and forward. Let's start by creating a test table that includes a Geography field and also a pair of Long/Lat fields that demonstrate how you can work with the geography functions even if you don't have geography/geometry fields in the database. Here's the CREATE command:CREATE TABLE [dbo].[Geo]( [id] [int] IDENTITY(1,1) NOT NULL, [Location] [geography] NULL, [Long] [float] NOT NULL, [Lat] [float] NOT NULL ) Now using plain SQL you can insert data into the table using geography::STGeoFromText SQL CLR function:insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.527200 45.712113)', 4326), -121.527200, 45.712113 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.517265 45.714240)', 4326), -121.517265, 45.714240 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.511536 45.714825)', 4326), -121.511536, 45.714825) The STGeomFromText function accepts a string that points to a geometric item (a point here but can also be a line or path or polygon and many others). You also need to provide an SRID (Spatial Reference System Identifier) which is an integer value that determines the rules for how geography/geometry values are calculated and returned. For mapping/distance functionality you typically want to use 4326 as this is the format used by most mapping software and geo-location libraries like Google and Bing. The spatial data in the Location field is stored in binary format which looks something like this: Once the location data is in the database you can query the data and do simple distance computations very easily. For example to calculate the distance of each of the values in the database to another spatial point is very easy to calculate. Distance calculations compare two points in space using a direct line calculation. For our example I'll compare a new point to all the points in the database. Using the Location field the SQL looks like this:-- create a source point DECLARE @s geography SET @s = geography:: STGeomFromText('POINT(-121.527200 45.712113)' , 4326); --- return the ids select ID, Location as Geo , Location .ToString() as Point , @s.STDistance( Location) as distance from Geo order by distance The code defines a new point which is the base point to compare each of the values to. You can also compare values from the database directly, but typically you'll want to match a location to another location and determine the difference for which you can use the geography::STDistance function. This query produces the following output: The STDistance function returns the straight line distance between the passed in point and the point in the database field. The result for SRID 4326 is always in meters. Notice that the first value passed was the same point so the difference is 0. The other two points are two points here in town in Hood River a little ways away - 808 and 1256 meters respectively. Notice also that you can order the result by the resulting distance, which effectively gives you results that are ordered radially out from closer to further away. This is great for searches of points of interest near a central location (YOU typically!). These geolocation functions are also available to you if you don't use the Geography/Geometry types, but plain float values. It's a little more work, as each point has to be created in the query using the string syntax, but the following code doesn't use a geography field but produces the same result as the previous query.--- using float fields select ID, geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326), geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326). ToString(), @s.STDistance( geography::STGeomFromText ('POINT(' + STR(long ,15, 7) + ' ' + Str(lat ,15, 7) + ')' , 4326)) as distance from geo order by distance Spatial Data in the Entity Framework Prior to Entity Framework 5.0 on .NET 4.5 consuming of the data above required using stored procedures or raw SQL commands to access the spatial data. In Entity Framework 5 however, Microsoft introduced the new DbGeometry and DbGeography types. These immutable location types provide a bunch of functionality for manipulating spatial points using geometry functions which in turn can be used to do common spatial queries like I described in the SQL syntax above. The DbGeography/DbGeometry types are immutable, meaning that you can't write to them once they've been created. They are a bit odd in that you need to use factory methods in order to instantiate them - they have no constructor() and you can't assign to properties like Latitude and Longitude. Creating a Model with Spatial Data Let's start by creating a simple Entity Framework model that includes a Location property of type DbGeography: public class GeoLocationContext : DbContext { public DbSet<GeoLocation> Locations { get; set; } } public class GeoLocation { public int Id { get; set; } public DbGeography Location { get; set; } public string Address { get; set; } } That's all there's to it. When you run this now against SQL Server, you get a Geography field for the Location property, which looks the same as the Location field in the SQL examples earlier. Adding Spatial Data to the Database Next let's add some data to the table that includes some latitude and longitude data. An easy way to find lat/long locations is to use Google Maps to pinpoint your location, then right click and click on What's Here. Click on the green marker to get the GPS coordinates. To add the actual geolocation data create an instance of the GeoLocation type and use the DbGeography.PointFromText() factory method to create a new point to assign to the Location property:[TestMethod] public void AddLocationsToDataBase() { var context = new GeoLocationContext(); // remove all context.Locations.ToList().ForEach( loc => context.Locations.Remove(loc)); context.SaveChanges(); var location = new GeoLocation() { // Create a point using native DbGeography Factory method Location = DbGeography.PointFromText( string.Format("POINT({0} {1})", -121.527200,45.712113) ,4326), Address = "301 15th Street, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.714240, -121.517265), Address = "The Hatchery, Bingen" }; context.Locations.Add(location); location = new GeoLocation() { // Create a point using a helper function (lat/long) Location = CreatePoint(45.708457, -121.514432), Address = "Kaze Sushi, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.722780, -120.209227), Address = "Arlington, OR" }; context.Locations.Add(location); context.SaveChanges(); } As promised, a DbGeography object has to be created with one of the static factory methods provided on the type as the Location.Longitude and Location.Latitude properties are read only. Here I'm using PointFromText() which uses a "Well Known Text" format to specify spatial data. In the first example I'm specifying to create a Point from a longitude and latitude value, using an SRID of 4326 (just like earlier in the SQL examples). You'll probably want to create a helper method to make the creation of Points easier to avoid that string format and instead just pass in a couple of double values. Here's my helper called CreatePoint that's used for all but the first point creation in the sample above:public static DbGeography CreatePoint(double latitude, double longitude) { var text = string.Format(CultureInfo.InvariantCulture.NumberFormat, "POINT({0} {1})", longitude, latitude); // 4326 is most common coordinate system used by GPS/Maps return DbGeography.PointFromText(text, 4326); } Using the helper the syntax becomes a bit cleaner, requiring only a latitude and longitude respectively. Note that my method intentionally swaps the parameters around because Latitude and Longitude is the common format I've seen with mapping libraries (especially Google Mapping/Geolocation APIs with their LatLng type). When the context is changed the data is written into the database using the SQL Geography type which looks the same as in the earlier SQL examples shown. Querying Once you have some location data in the database it's now super easy to query the data and find out the distance between locations. A common query is to ask for a number of locations that are near a fixed point - typically your current location and order it by distance. Using LINQ to Entities a query like this is easy to construct:[TestMethod] public void QueryLocationsTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 kilometers ordered by distance var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) < 5000) .OrderBy( loc=> loc.Location.Distance(sourcePoint) ) .Select( loc=> new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n0} meters)", location.Address, location.Distance); } } This example produces: 301 15th Street, Hood River (0 meters)The Hatchery, Bingen (809 meters)Kaze Sushi, Hood River (1,074 meters) The first point in the database is the same as my source point I'm comparing against so the distance is 0. The other two are within the 5 mile radius, while the Arlington location which is 65 miles or so out is not returned. The result is ordered by distance from closest to furthest away. In the code, I first create a source point that is the basis for comparison. The LINQ query then selects all locations that are within 5km of the source point using the Location.Distance() function, which takes a source point as a parameter. You can either use a pre-defined value as I'm doing here, or compare against another database DbGeography property (say when you have to points in the same database for things like routes). What's nice about this query syntax is that it's very clean and easy to read and understand. You can calculate the distance and also easily order by the distance to provide a result that shows locations from closest to furthest away which is a common scenario for any application that places a user in the context of several locations. It's now super easy to accomplish this. Meters vs. Miles As with the SQL Server functions, the Distance() method returns data in meters, so if you need to work with miles or feet you need to do some conversion. Here are a couple of helpers that might be useful (can be found in GeoUtils.cs of the sample project):/// <summary> /// Convert meters to miles /// </summary> /// <param name="meters"></param> /// <returns></returns> public static double MetersToMiles(double? meters) { if (meters == null) return 0F; return meters.Value * 0.000621371192; } /// <summary> /// Convert miles to meters /// </summary> /// <param name="miles"></param> /// <returns></returns> public static double MilesToMeters(double? miles) { if (miles == null) return 0; return miles.Value * 1609.344; } Using these two helpers you can query on miles like this:[TestMethod] public void QueryLocationsMilesTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 miles ordered by distance var fiveMiles = GeoUtils.MilesToMeters(5); var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) <= fiveMiles) .OrderBy(loc => loc.Location.Distance(sourcePoint)) .Select(loc => new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n1} miles)", location.Address, GeoUtils.MetersToMiles(location.Distance)); } } which produces: 301 15th Street, Hood River (0.0 miles)The Hatchery, Bingen (0.5 miles)Kaze Sushi, Hood River (0.7 miles) Nice 'n simple. .NET 4.5 Only Note that DbGeography and DbGeometry are exclusive to Entity Framework 5.0 (not 4.4 which ships in the same NuGet package or installer) and requires .NET 4.5. That's because the new DbGeometry and DbGeography (and related) types are defined in the 4.5 version of System.Data.Entity which is a CLR assembly and is only updated by major versions of .NET. Why this decision was made to add these types to System.Data.Entity rather than to the frequently updated EntityFramework assembly that would have possibly made this work in .NET 4.0 is beyond me, especially given that there are no native .NET framework spatial types to begin with. I find it also odd that there is no native CLR spatial type. The DbGeography and DbGeometry types are specific to Entity Framework and live on those assemblies. They will also work for general purpose, non-database spatial data manipulation, but then you are forced into having a dependency on System.Data.Entity, which seems a bit silly. There's also a System.Spatial assembly that's apparently part of WCF Data Services which in turn don't work with Entity framework. Another example of multiple teams at Microsoft not communicating and implementing the same functionality (differently) in several different places. Perplexed as a I may be, for EF specific code the Entity framework specific types are easy to use and work well. Working with pre-.NET 4.5 Entity Framework and Spatial Data If you can't go to .NET 4.5 just yet you can also still use spatial features in Entity Framework, but it's a lot more work as you can't use the DbContext directly to manipulate the location data. You can still run raw SQL statements to write data into the database and retrieve results using the same TSQL syntax I showed earlier using Context.Database.ExecuteSqlCommand(). Here's code that you can use to add location data into the database:[TestMethod] public void RawSqlEfAddTest() { string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT({0} {1})', 4326),@p0 )"; var sql = string.Format(sqlFormat,-121.527200, 45.712113); Console.WriteLine(sql); var context = new GeoLocationContext(); Assert.IsTrue(context.Database.ExecuteSqlCommand(sql,"301 N. 15th Street") > 0); } Here I'm using the STGeomFromText() function to add the location data. Note that I'm using string.Format here, which usually would be a bad practice but is required here. I was unable to use ExecuteSqlCommand() and its named parameter syntax as the longitude and latitude parameters are embedded into a string. Rest assured it's required as the following does not work:string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT(@p0 @p1)', 4326),@p2 )";context.Database.ExecuteSqlCommand(sql, -121.527200, 45.712113, "301 N. 15th Street") Explicitly assigning the point value with string.format works however. There are a number of ways to query location data. You can't get the location data directly, but you can retrieve the point string (which can then be parsed to get Latitude and Longitude) and you can return calculated values like distance. Here's an example of how to retrieve some geo data into a resultset using EF's and SqlQuery method:[TestMethod] public void RawSqlEfQueryTest() { var sqlFormat = @" DECLARE @s geography SET @s = geography:: STGeomFromText('POINT({0} {1})' , 4326); SELECT Address, Location.ToString() as GeoString, @s.STDistance( Location) as Distance FROM GeoLocations ORDER BY Distance"; var sql = string.Format(sqlFormat, -121.527200, 45.712113); var context = new GeoLocationContext(); var locations = context.Database.SqlQuery<ResultData>(sql); Assert.IsTrue(locations.Count() > 0); foreach (var location in locations) { Console.WriteLine(location.Address + " " + location.GeoString + " " + location.Distance); } } public class ResultData { public string GeoString { get; set; } public double Distance { get; set; } public string Address { get; set; } } Hopefully you don't have to resort to this approach as it's fairly limited. Using the new DbGeography/DbGeometry types makes this sort of thing so much easier. When I had to use code like this before I typically ended up retrieving data pks only and then running another query with just the PKs to retrieve the actual underlying DbContext entities. This was very inefficient and tedious but it did work. Summary For the current project I'm working on we actually made the switch to .NET 4.5 purely for the spatial features in EF 5.0. This app heavily relies on spatial queries and it was worth taking a chance with pre-release code to get this ease of integration as opposed to manually falling back to stored procedures or raw SQL string queries to return spatial specific queries. Using native Entity Framework code makes life a lot easier than the alternatives. It might be a late addition to Entity Framework, but it sure makes location calculations and storage easy. Where do you want to go today? ;-) Resources Download Sample Project© Rick Strahl, West Wind Technologies, 2005-2012Posted in ADO.NET Sql Server .NET Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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