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  • Friendly way to parse XDocument

    - by Oli
    I have a class that various different XML schemes are created from. I create the various dynamic XDocuments via one (Very long) statement using conditional operators for optional elements and attributes. I now need to convert the XDocuments back to the class but as they are coming from different schemes many elements and sub elements may be optional. The only way I know of doing this is to use a lot of if statements. This approach doesn't seem very LINQ and uses a great deal more code than when I create the XDocument so I wondered if there is a better way to do this? An example would be to get <?xml version="1.0"?> <root xmlns="somenamespace"> <object attribute1="This is Optional" attribute2="This is required"> <element1>Required</element1> <element1>Optional</element1> <List1> Optional List Of Elements </List1> <List2> Required List Of Elements </List2> </object> </root> Into public class Object() { public string Attribute1; public string Attribute2; public string Element1; public string Element2; public List<ListItem1> List1; public List<ListItem2> List2; } In a more LINQ friendly way than this: public bool ParseXDocument(string xml) { XNamespace xn = "somenamespace"; XDocument document = XDocument.Parse(xml); XElement elementRoot = description.Element(xn + "root"); if (elementRoot != null) { //Get Object Element XElement elementObject = elementRoot.Element(xn + "object"); if(elementObject != null) { if(elementObject.Attribute(xn + "attribute1") != null) { Attribute1 = elementObject.Attribute(xn + "attribute1"); } if(elementObject.Attribute(xn + "attribute2") != null) { Attribute2 = elementObject.Attribute(xn + "attribute2"); } else { //This is a required Attribute so return false return false; } //If, If/Elses get deeper and deeper for the next elements and lists etc.... } else { //Object is a required element so return false return false; } } else { //Root is a required element so return false return false; } return true; } Update: Just to clarify the ParseXDocument method is inside the "Object" class. Every time an xml document is received the Object class instance has some or all of it's values updated.

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  • Transmitting complex objects using TCP

    - by Rakesh K
    I have a client server application in which I need to transmit a user defined object from Client to Server using TCP connection. My object is of the following structure: class Conversation { private string convName, convOwner; public ArrayList convUsers; public string getConvName() { return this.convName; } public string getConvOwner() { return this.convOwner; } } Please help me how to transmit this object at from client and again de-serialize it into appropriate object at server side.

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  • Dynamically generating method names in rails

    - by badnaam
    I need to generate links in my views using the url helpers such as user_path(@user), the catch is, in some cases I don't know what model I am creating this link for i.e. whether it is a user or a store or someting else I would like to be able to determine this on the fly and call the appropriate view helper, currently I am doing the following, but I am wondering if there is a drier way of doing it. if object.class == "Store" store_path(object) elsif object.class == "User" user_path(object) ...etc

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  • C# Dispose() -clarification

    - by nettguy
    When i call object.Dispose(); Will CLR immediately destroy the object from memory or mark the object for removal in it's next cycle?. We are calling GC.SuppressFinalize() immediately after Dispose(),Does it mean ,"Don't collect the object again for dispose,because it is already submitted to displose". Actually which generation is responsible for destruction ,i guess generation 2.

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  • LinqToXML why does my object go out of scope? Also should I be doing a group by?

    - by Kettenbach
    Hello All, I have an IEnumerable<someClass>. I need to transform it into XML. There is a property called 'ZoneId'. I need to write some XML based on this property, then I need some decendent elements that provide data relevant to the ZoneId. I know I need some type of grouping. Here's what I have attempted thus far without much success. **inventory is an IEnumerable<someClass>. So I query inventory for unique zones. This works ok. var zones = inventory.Select(c => new { ZoneID = c.ZoneId , ZoneName = c.ZoneName , Direction = c.Direction }).Distinct(); No I want to create xml based on zones and place. ***place is a property of 'someClass'. var xml = new XElement("MSG_StationInventoryList" , new XElement("StationInventory" , zones.Select(station => new XElement("station-id", station.ZoneID) , new XElement("station-name", station.ZoneName)))); This does not compile as "station" is out of scope when I try to add the "station-name" element. However is I remove the paren after 'ZoneId', station is in scope and I retreive the station-name. Only problem is the element is then a decendant of 'station-id'. This is not the desired output. They should be siblings. What am I doing wrong? Lastly after the "station-name" element, I will need another complex type which is a collection. Call it "places'. It will have child elements called "place". its data will come from the IEnumerable and I will only want "places" that have the "ZoneId" for the current zone. Can anyone point me in the right direction? Is it a mistake select distinct zones from the original IEnumerable? This object has all the data I need within it. I just need to make it heirarchical. Thanks for any pointers all. Cheers, Chris in San Diego

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  • mod_mono 'Service Temporarily Unavailable' issue

    - by Charlie Somerville
    I've deployed an ASP.NET web application on a Linux (Debian) server running Apache 2.2 and mod_mono 1.9 It's working well, however Mono occasionally segfaults and uses the entire CPU which causes the website to stop working and display 'Service Temporarily Unavailable' Killing mono fixes it, but obviously this isn't a good solution. I tailed the system log after this happened and I saw the following error messages from the kernel: Apr 20 01:49:37 charliesomerville kernel: [1596436.204158] mono[17909]: segfault at b645f671 ip b645f671 sp b4ffb604 error 4<6>mono[19047]: segfault at b645f66e ip b645f66e sp b4bf7604 error 4<6>mono[18017]: segfault at b645f66e ip b645f66e sp b52fe604 error 4<6>mono[19668]: segfault at b645f5e6 ip b645f5e6 sp b48f4604 error 4<6>mono[22565]: segfault at b645f674 ip b645f674 sp b45f1604 error 4<6>mono[17700]: segfault at b645f661 ip b645f661 sp b51fd604 error 4<6>mono[19596]: segfault at b645f5e6 ip b645f5e6 sp b49f5604 error 4 Apr 20 01:49:37 charliesomerville kernel: [1596436.208172] mono[23219]: segfault at b645f66e ip b645f66e sp b44f0604 error 4 At the end of Apache's error.log are the following errors: [Tue Apr 20 03:10:23 2010] [error] (70014)End of file found: read_data failed [Tue Apr 20 03:10:23 2010] [error] Command stream corrupted, last command was 1 [Tue Apr 20 03:10:23 2010] [error] Command stream corrupted, last command was 1 [Tue Apr 20 03:10:23 2010] [error] Command stream corrupted, last command was 1 System.ArgumentNullException: null key Parameter name: key at System.Collections.Hashtable.get_Item (System.Object key) [0x00000] at System.Runtime.Serialization.SerializationCallbacks.GetSerializationCallbacks (System.Type t) [0x00000] at System.Runtime.Serialization.ObjectManager.RaiseOnDeserializingEvent (System.Object obj) [0x00000] at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ReadObjectContent (System.IO.BinaryReader reader, System.Runtime.Serialization.Formatters.Binary.TypeMetadata metadata, Int64 objectId, System.Object& objectInstance, System.Runtime.Serialization.SerializationInfo& info) [0x00000] at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ReadObjectInstance (System.IO.BinaryReader reader, Boolean isRuntimeObject, Boolean hasTypeInfo, System.Int64& objectId, System.Object& value, System.Runtime.Serialization.SerializationInfo& info) [0x00000] at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ReadObject (BinaryElement element, System.IO.BinaryReader reader, System.Int64& objectId, System.Object& value, System.Runtime.Serialization.SerializationInfo& info) [0x00000] at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ReadNextObject (System.IO.BinaryReader reader) [0x00000] at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ReadObjectGraph (System.IO.BinaryReader reader, Boolean readHeaders, System.Object& result, System.Runtime.Remoting.Messaging.Header[]& headers) [0x00000] at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.NoCheckDeserialize (System.IO.Stream serializationStream, System.Runtime.Remoting.Messaging.HeaderHandler handler) [0x00000] at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize (System.IO.Stream serializationStream) [0x00000] at System.Runtime.Remoting.Channels.CADSerializer.DeserializeObject (System.IO.MemoryStream mem) [0x00000] at System.Runtime.Remoting.RemotingServices.GetDomainProxy (System.AppDomain domain) [0x00000] at System.AppDomain.CreateDomain (System.String friendlyName, System.Security.Policy.Evidence securityInfo, System.AppDomainSetup info) [0x00000] at System.Web.Hosting.ApplicationHost.CreateApplicationHost (System.Type hostType, System.String virtualDir, System.String physicalDir) [0x00000] at Mono.WebServer.VPathToHost.CreateHost (Mono.WebServer.ApplicationServer server, Mono.WebServer.WebSource webSource) [0x00000] at Mono.WebServer.ApplicationServer.GetApplicationForPath (System.String vhost, Int32 port, System.String path, Boolean defaultToRoot) [0x00000] at (wrapper remoting-invoke-with-check) Mono.WebServer.ApplicationServer:GetApplicationForPath (string,int,string,bool) at Mono.WebServer.ModMonoWorker.GetOrCreateApplication (System.String vhost, Int32 port, System.String filepath, System.String virt) [0x00000] at Mono.WebServer.ModMonoWorker.InnerRun (System.Object state) [0x00000] at Mono.WebServer.ModMonoWorker.Run (System.Object state) [0x00000] [Tue Apr 20 03:10:26 2010] [error] (70014)End of file found: read_data failed [Tue Apr 20 03:10:26 2010] [error] Command stream corrupted, last command was -1 Along with the above errors, Apache's error.log is packed with hundreds (if not thousands) of the following error: Maximum number (20) of concurrent mod_mono requests to /tmp/mod_mono_dashboard_default_2.lock reached. Droping request. At the moment, I'm thinking there might be something wrong with configuration here (it's basically running on out-of-the-box config)

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  • IIS 7.5 Manager crashes when adding a custom error page

    - by dig412
    I'm running a local IIS 7.5 server in Win 7 Pro, and I'm trying to add a custom error page for 403 responses. When I click OK to add a custom error page for my site, IIS Manager just vanishes. The server is still running, and I can re-start IIS Manager, but the new page has not been saved. I've also tried adding it directly to web.config, but that just gives me The page cannot be displayed because an internal server error has occurred. Does anyone know why this might be happening? Edit: The event log implies that an invalid character in the path caused the crash, but It occured even when I copied & pasted a path from a valid entry. Application error log: IISMANAGER_CRASH IIS Manager terminated unexpectedly. Exception:System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --- System.ArgumentException: Illegal characters in path. at System.IO.Path.CheckInvalidPathChars(String path) at System.IO.Path.IsPathRooted(String path) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsForm.OnAccept() at Microsoft.Web.Management.Client.Win32.TaskForm.OnOKButtonClick(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Form.ShowDialog(IWin32Window owner) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.ShowDialogInternal(Form form, IWin32Window parent) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.Microsoft.Web.Management.Client.Win32.IManagementUIService.ShowDialog(DialogForm form) at Microsoft.Web.Management.Client.Win32.ModulePage.ShowDialog(DialogForm form) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsPage.AddCustomError() --- End of inner exception stack trace --- at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at Microsoft.Web.Management.Client.TaskList.InvokeMethod(String methodName, Object userData) at Microsoft.Web.Management.Host.UserInterface.Tasks.MethodTaskItemLine.InvokeMethod() at System.Windows.Forms.LinkLabel.OnMouseUp(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.Label.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at Microsoft.Web.Management.Host.Shell.ShellApplication.Execute(Boolean localDevelopmentMode, Boolean resetPreferences, Boolean resetPreferencesNoLaunch) Process:InetMgr

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  • Using an alternate search platform in Commerce Server 2009

    - by Lewis Benge
    Although Microsoft Commerce Server 2009's architecture is built upon Microsoft SQL Server, and has the full power of the SQL Full Text Indexing Search Platform, there are time however when you may require a richer or alternate search platform. One of these scenarios if when you want to implement a faceted (refinement) search into your site, which provides dynamic refinements based on the search results dataset. Faceted search is becoming popular in most online retail environments as a way of providing an enhanced user experience when browsing a larger catalogue. This is powerful for two reasons, firstly with a traditional search it is down to a user to think of a search term suitable for the product they are trying to find. This typically will not return similar products or help in any way to refine a larger dataset. Faceted searches on the other hand provide a comprehensive list of product properties, grouped together by similarity to help the user narrow down the results returned, as the user progressively restricts the search criteria by selecting additional criteria to search again, these facets needs to continually refresh. The whole experience allows users to explore alternate brands, price-ranges, or find products they hadn't initially thought of or where looking for in a bid to enhance cross sell in the retail environment. The second advantage of this type of search from a business perspective is also to harvest the search result to start to profile your user. Even though anonymous users may routinely visit your site, and will not necessarily register or complete a transaction to build up marketing data- profiling, you can still achieve the same result by recording search facets used within the search sequence. Below is a faceted search scenario generated from eBay using the search term "server". By creating a search profile of clicking through Computer & Networking -> Servers -> Dell - > New and recording this information against my user profile you can start to predict with a lot more certainty what types of products I am interested in. This will allow you to apply shopping-cart analysis against your search data and provide great cross-sale or advertising opportunity, or personalise the user experience based on your prediction of what the user may be interested in. This type of search is extremely beneficial in e-Commerce environments but achieving it out of the box with Commerce Server and SQL Full Text indexing can be challenging. In many deployments it is often easier to use an alternate search platform such as Microsoft's FAST, Apache SOLR, or Endecca, however you still want these products to integrate natively into Commerce Server to ensure that up-to-date inventory information is presented, profile information is generated, and you provide a consistant API. To do so we make the most of the Commerce Server extensibilty points called operation sequence components. In this example I will be talking about Apache Solr hosted on Apache Tomcat, in this specific example I have used the SolrNet C# library to interface to the Java platform. Also I am not going to talk about Solr configuration of indexing – but in a production envionrment this would typically happen by using Powershell to call the Commerce Server management webservice to export your catalog as XML, apply an XSLT transform to the file to make it conform to SOLR and use a simple HTTP Post to send it to the search enginge for indexing. Essentially a sequance component is a step in a serial workflow used to call a data repository (which in most cases is usually the Commerce Server pipelines or databases) and map to and from a Commerce Entity object whilst enforcing any business rules. So the first step in the process is to add a new class library to your existing Commerce Server site. You will need to use a new library as Sequence Components will need to be strongly named to be deployed. Once you are inside of your new project, add a new class file and add a reference to the Microsoft.Commerce.Providers, Microsoft.Commerce.Contracts and the Microsoft.Commerce.Broker assemblies. Now make your new class derive from the base object Microsoft.Commerce.Providers.Components.OperationSequanceComponent and overide the ExecuteQueryMethod. Your screen will then look something similar ot this: As all we are doing on this component is conducting a search we are only interested in the ExecuteQuery method. This method accepts three arguments, queryOperation, operationCache, and response. The queryOperation will be the object in which we receive our search parameters, the cache allows access to the Commerce Server cache allowing us to store regulary accessed information, and the response object is the object which we will return the result of our search upon. Inside this method is simply where we are going to inject our logic for our third party search platform. As I am not going to explain the inner-workings of actually making a SOLR call, I'll simply provide the sample code here. I would highly recommend however looking at the SolrNet wiki as they have some great explinations of how the API works. What you will find however is that there are some further extensions required when attempting to integrate a custom search provider. Firstly you out of the box the CommerceQueryOperation you will receive into the method when conducting a search against a catalog is specifically geared towards a SQL Full Text Search with properties such as a Where clause. To make the operation you receive more relevant you will need to create another class, this time derived from Microsoft.Commerce.Contract.Messages.CommerceSearchCriteria and within this you need to detail the properties you will require to allow you to submit as parameters to the SOLR search API. My exmaple looks like this: [DataContract(Namespace = "http://schemas.microsoft.com/microsoft-multi-channel-commerce-foundation/types/2008/03")] public class CommerceCatalogSolrSearch : CommerceSearchCriteria { private Dictionary<string, string> _facetQueries;   public CommerceCatalogSolrSearch() { _facetQueries = new Dictionary<String, String>();   }     public Dictionary<String, String> FacetQueries { get { return _facetQueries; } set { _facetQueries = value; } }   public String SearchPhrase{ get; set; } public int PageIndex { get; set; } public int PageSize { get; set; } public IEnumerable<String> Facets { get; set; }   public string Sort { get; set; }   public new int FirstItemIndex { get { return (PageIndex-1)*PageSize; } }   public int LastItemIndex { get { return FirstItemIndex + PageSize; } } }  To allow you to construct a CommerceQueryOperation call within the API you will also need to construct another class to derived from Microsoft.Commerce.Common.MessageBuilders.CommerceSearchCriteriaBuilder and is simply used to construct an instance of the CommerceQueryOperation you have just created and expose the properties you want set. My Message builder looks like this: public class CommerceCatalogSolrSearchBuilder : CommerceSearchCriteriaBuilder { private CommerceCatalogSolrSearch _solrSearch;   public CommerceCatalogSolrSearchBuilder() { _solrSearch = new CommerceCatalogSolrSearch(); }   public String SearchPhrase { get { return _solrSearch.SearchPhrase; } set { _solrSearch.SearchPhrase = value; } }   public int PageIndex { get { return _solrSearch.PageIndex; } set { _solrSearch.PageIndex = value; } }   public int PageSize { get { return _solrSearch.PageSize; } set { _solrSearch.PageSize = value; } }   public Dictionary<String,String> FacetQueries { get { return _solrSearch.FacetQueries; } set { _solrSearch.FacetQueries = value; } }   public String[] Facets { get { return _solrSearch.Facets.ToArray(); } set { _solrSearch.Facets = value; } } public override CommerceSearchCriteria ToSearchCriteria() { return _solrSearch; } }  Once you have these two classes in place you can now safely cast the CommerceOperation you receive as an argument of the overidden ExecuteQuery method in the SequenceComponent to the CommerceCatalogSolrSearch operation you have just created, e.g. public CommerceCatalogSolrSearch TryGetSearchCriteria(CommerceOperation operation) { var searchCriteria = operation as CommerceQueryOperation; if (searchCriteria == null) throw new Exception("No search criteria present");   var local = (CommerceCatalogSolrSearch) searchCriteria.SearchCriteria; if (local == null) throw new Exception("Unexpected Search Criteria in Operation");   return local; }  Now you have all of your search parameters present, you can go off an call the external search platform API. You will of-course get proprietry objects returned, so the next step in the process is to convert the results being returned back into CommerceEntities. You do this via another extensibility point within the Commerce Server API called translatators. Translators are another separate class, this time derived inheriting the interface Microsoft.Commerce.Providers.Translators.IToCommerceEntityTranslator . As you can imaginge this interface is specific for the conversion of the object TO a CommerceEntity, you will need to implement a separate interface if you also need to go in the opposite direction. If you implement the required method for the interace you will get a single translate method which has a source onkect, destination CommerceEntity, and a collection of properties as arguments. For simplicity sake in this example I have hard-coded the mappings, however best practice would dictate you map the objects using your metadatadefintions.xml file . Once complete your translator would look something like the following: public class SolrEntityTranslator : IToCommerceEntityTranslator { #region IToCommerceEntityTranslator Members   public void Translate(object source, CommerceEntity destinationCommerceEntity, CommercePropertyCollection propertiesToReturn) { if (source.GetType().Equals(typeof (SearchProduct))) { var searchResult = (SearchProduct) source;   destinationCommerceEntity.Id = searchResult.ProductId; destinationCommerceEntity.SetPropertyValue("DisplayName", searchResult.Title); destinationCommerceEntity.ModelName = "Product";   } }  Once you have a translator in place you can then safely map the results of your search platform into Commerce Entities and attach them on to the CommerceResponse object in a fashion similar to this: foreach (SearchProduct result in matchingProducts) { var destinationEntity = new CommerceEntity(_returnModelName);   Translator.ToCommerceEntity(result, destinationEntity, _queryOperation.Model.Properties); response.CommerceEntities.Add(destinationEntity); }  In SOLR I actually have two objects being returned – a product, and a collection of facets so I have an additional translator for facet (which maps to a custom facet CommerceEntity) and my facet response from SOLR is passed into the Translator helper class seperatley. When all of this is pieced together you have sucessfully completed the extensiblity point coding. You would have created a new OperationSequanceComponent, a custom SearchCritiera object and message builder class, and translators to convert the objects into Commerce Entities. Now you simply need to configure them, and can start calling them in your code. Make sure you sign you assembly, compile it and identiy its signature. Next you need to put this a reference of your new assembly into the Channel.Config configuration file replacing that of the existing SQL Full Text component: You will also need to add your translators to the Translators node of your Channel.Config too: Lastly add any custom CommerceEntities you have developed to your MetaDataDefintions.xml file. Your configuration is now complete, and you should now be able to happily make a call to the Commerce Foundation API, which will act as a proxy to your third party search platform and return back CommerceEntities of your search results. If you require data to be enriched, or logged, or any other logic applied then simply add further sequence components into the OperationSequence (obviously keeping the search response first) to the node of your Channel.Config file. Now to call your code you simply request it as per any other CommerceQuery operation, but taking into account you may be receiving multiple types of CommerceEntity returned: public KeyValuePair<FacetCollection ,List<Product>> DoFacetedProductQuerySearch(string searchPhrase, string orderKey, string sortOrder, int recordIndex, int recordsPerPage, Dictionary<string, string> facetQueries, out int totalItemCount) { var products = new List<Product>(); var query = new CommerceQuery<CatalogEntity, CommerceCatalogSolrSearchBuilder>();   query.SearchCriteria.PageIndex = recordIndex; query.SearchCriteria.PageSize = recordsPerPage; query.SearchCriteria.SearchPhrase = searchPhrase; query.SearchCriteria.FacetQueries = facetQueries;     totalItemCount = 0; CommerceResponse response = SiteContext.ProcessRequest(query.ToRequest()); var queryResponse = response.OperationResponses[0] as CommerceQueryOperationResponse;   // No results. Return the empty list if (queryResponse != null && queryResponse.CommerceEntities.Count == 0) return new KeyValuePair<FacetCollection, List<Product>>();   totalItemCount = (int)queryResponse.TotalItemCount;   // Prepare a multi-operation to retrieve the product variants var multiOperation = new CommerceMultiOperation();     //Add products to results foreach (Product product in queryResponse.CommerceEntities.Where(x => x.ModelName == "Product")) { var productQuery = new CommerceQuery<Product>(Product.ModelNameDefinition); productQuery.SearchCriteria.Model.Id = product.Id; productQuery.SearchCriteria.Model.CatalogId = product.CatalogId;   var variantQuery = new CommerceQueryRelatedItem<Variant>(Product.RelationshipName.Variants);   productQuery.RelatedOperations.Add(variantQuery);   multiOperation.Add(productQuery); }   CommerceResponse variantsResponse = SiteContext.ProcessRequest(multiOperation.ToRequest()); foreach (CommerceQueryOperationResponse queryOpResponse in variantsResponse.OperationResponses) { if (queryOpResponse.CommerceEntities.Count() > 0) products.Add(queryOpResponse.CommerceEntities[0]); }   //Get facet collection FacetCollection facetCollection = queryResponse.CommerceEntities.Where(x => x.ModelName == "FacetCollection").FirstOrDefault();     return new KeyValuePair<FacetCollection, List<Product>>(facetCollection, products); }    ..And that is it – simply a few classes and some configuration will allow you to extend the Commerce Server query operations to call a third party search platform, whilst still maintaing a unifed API in the remainder of your code. This logic stands for any extensibility within CommerceServer, which requires excution in a serial fashioon such as call to LOB systems or web service to validate or enrich data. Feel free to use this example on other applications, and if you have any questions please feel free to e-mail and I'll help out where I can!

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • Minecraft Style Chunk building problem

    - by David Torrey
    I'm having some problems with speed in my chunk engine. I timed it out, and in its current state it takes a total ~5 seconds per chunk to fill each face's list. I have a check to see if each face of a block is visible and if it is not visible, it skips it and moves on. I'm using a dictionary (unordered map) because it makes sense memorywise to just not have an entry if there is no block. I've tracked my problem down to testing if there is an entry, and accessing an entry if it does exist. If I remove the tests to see if there is an entry in the dictionary for an adjacent block, or if the block type itself is seethrough, it runs within about 2-4 milliseconds. so here's my question: Is there a faster way to check for an entry in a dictionary than .ContainsKey()? As an aside, I tried TryGetValue() and it doesn't really help with the speed that much. If I remove the ContainsKey() and keep the test where it does the IsSeeThrough for each block, it halves the time, but it's still about 2-3 seconds. It only drops to 2-4ms if I remove BOTH checks. Here is my code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Runtime.InteropServices; using OpenTK; using OpenTK.Graphics.OpenGL; using System.Drawing; namespace Anabelle_Lee { public enum BlockEnum { air = 0, dirt = 1, } [StructLayout(LayoutKind.Sequential,Pack=1)] public struct Coordinates<T1> { public T1 x; public T1 y; public T1 z; public override string ToString() { return "(" + x + "," + y + "," + z + ") : " + typeof(T1); } } public struct Sides<T1> { public T1 left; public T1 right; public T1 top; public T1 bottom; public T1 front; public T1 back; } public class Block { public int blockType; public bool SeeThrough() { switch (blockType) { case 0: return true; } return false ; } public override string ToString() { return ((BlockEnum)(blockType)).ToString(); } } class Chunk { private Dictionary<Coordinates<byte>, Block> mChunkData; //stores the block data private Sides<List<Coordinates<byte>>> mVBOVertexBuffer; private Sides<int> mVBOHandle; //private bool mIsChanged; private const byte mCHUNKSIZE = 16; public Chunk() { } public void InitializeChunk() { //create VBO references #if DEBUG Console.WriteLine ("Initializing Chunk"); #endif mChunkData = new Dictionary<Coordinates<byte> , Block>(); //mIsChanged = true; GL.GenBuffers(1, out mVBOHandle.left); GL.GenBuffers(1, out mVBOHandle.right); GL.GenBuffers(1, out mVBOHandle.top); GL.GenBuffers(1, out mVBOHandle.bottom); GL.GenBuffers(1, out mVBOHandle.front); GL.GenBuffers(1, out mVBOHandle.back); //make new list of vertexes for each face mVBOVertexBuffer.top = new List<Coordinates<byte>>(); mVBOVertexBuffer.bottom = new List<Coordinates<byte>>(); mVBOVertexBuffer.left = new List<Coordinates<byte>>(); mVBOVertexBuffer.right = new List<Coordinates<byte>>(); mVBOVertexBuffer.front = new List<Coordinates<byte>>(); mVBOVertexBuffer.back = new List<Coordinates<byte>>(); #if DEBUG Console.WriteLine("Chunk Initialized"); #endif } public void GenerateChunk() { #if DEBUG Console.WriteLine("Generating Chunk"); #endif for (byte i = 0; i < mCHUNKSIZE; i++) { for (byte j = 0; j < mCHUNKSIZE; j++) { for (byte k = 0; k < mCHUNKSIZE; k++) { Random blockLoc = new Random(); Coordinates<byte> randChunk = new Coordinates<byte> { x = i, y = j, z = k }; mChunkData.Add(randChunk, new Block()); mChunkData[randChunk].blockType = blockLoc.Next(0, 1); } } } #if DEBUG Console.WriteLine("Chunk Generated"); #endif } public void DeleteChunk() { //delete VBO references #if DEBUG Console.WriteLine("Deleting Chunk"); #endif GL.DeleteBuffers(1, ref mVBOHandle.left); GL.DeleteBuffers(1, ref mVBOHandle.right); GL.DeleteBuffers(1, ref mVBOHandle.top); GL.DeleteBuffers(1, ref mVBOHandle.bottom); GL.DeleteBuffers(1, ref mVBOHandle.front); GL.DeleteBuffers(1, ref mVBOHandle.back); //clear all vertex buffers ClearPolyLists(); #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void UpdateChunk() { #if DEBUG Console.WriteLine("Updating Chunk"); #endif ClearPolyLists(); //prepare buffers //for every entry in mChunkData map foreach(KeyValuePair<Coordinates<byte>,Block> feBlockData in mChunkData) { Coordinates<byte> checkBlock = new Coordinates<byte> { x = feBlockData.Key.x, y = feBlockData.Key.y, z = feBlockData.Key.z }; //check for polygonson the left side of the cube if (checkBlock.x > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x - 1, checkBlock.y, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } //check for polygons on the right side of the cube if (checkBlock.x < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x + 1, checkBlock.y, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } if (checkBlock.y > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y - 1, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } //check for polygons on the right side of the cube if (checkBlock.y < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y + 1, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } if (checkBlock.z > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z - 1)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } //check for polygons on the right side of the cube if (checkBlock.z < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z + 1)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } BuildBuffers(); #if DEBUG Console.WriteLine("Chunk Updated"); #endif } public void RenderChunk() { } public void LoadChunk() { #if DEBUG Console.WriteLine("Loading Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void SaveChunk() { #if DEBUG Console.WriteLine("Saving Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Saved"); #endif } private bool IsVisible(int pX,int pY,int pZ) { Block testBlock; Coordinates<byte> checkBlock = new Coordinates<byte> { x = Convert.ToByte(pX), y = Convert.ToByte(pY), z = Convert.ToByte(pZ) }; if (mChunkData.TryGetValue(checkBlock,out testBlock )) //if data exists { if (testBlock.SeeThrough() == true) //if existing data is not seethrough { return true; } } return true; } private void AddPoly(byte pX, byte pY, byte pZ, int BufferSide) { //create temp array GL.BindBuffer(BufferTarget.ArrayBuffer, BufferSide); if (BufferSide == mVBOHandle.front) { //front face mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.right) { //back face mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.top) { //left face mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.bottom) { //right face mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.front) { //top face mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.back) { //bottom face mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); } } private void BuildBuffers() { #if DEBUG Console.WriteLine("Building Chunk Buffers"); #endif GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.front); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.front.Count), mVBOVertexBuffer.front.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.back); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.back.Count), mVBOVertexBuffer.back.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.left); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.left.Count), mVBOVertexBuffer.left.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.right); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.right.Count), mVBOVertexBuffer.right.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.top); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.top.Count), mVBOVertexBuffer.top.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.bottom); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.bottom.Count), mVBOVertexBuffer.bottom.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer,0); #if DEBUG Console.WriteLine("Chunk Buffers Built"); #endif } private void ClearPolyLists() { #if DEBUG Console.WriteLine("Clearing Polygon Lists"); #endif mVBOVertexBuffer.top.Clear(); mVBOVertexBuffer.bottom.Clear(); mVBOVertexBuffer.left.Clear(); mVBOVertexBuffer.right.Clear(); mVBOVertexBuffer.front.Clear(); mVBOVertexBuffer.back.Clear(); #if DEBUG Console.WriteLine("Polygon Lists Cleared"); #endif } }//END CLASS }//END NAMESPACE

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  • Abstracting functionality

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/22/abstracting-functionality.aspxWhat is more important than data? Functionality. Yes, I strongly believe we should switch to a functionality over data mindset in programming. Or actually switch back to it. Focus on functionality Functionality once was at the core of software development. Back when algorithms were the first thing you heard about in CS classes. Sure, data structures, too, were important - but always from the point of view of algorithms. (Niklaus Wirth gave one of his books the title “Algorithms + Data Structures” instead of “Data Structures + Algorithms” for a reason.) The reason for the focus on functionality? Firstly, because software was and is about doing stuff. Secondly because sufficient performance was hard to achieve, and only thirdly memory efficiency. But then hardware became more powerful. That gave rise to a new mindset: object orientation. And with it functionality was devalued. Data took over its place as the most important aspect. Now discussions revolved around structures motivated by data relationships. (John Beidler gave his book the title “Data Structures and Algorithms: An Object Oriented Approach” instead of the other way around for a reason.) Sure, this data could be embellished with functionality. But nevertheless functionality was second. When you look at (domain) object models what you mostly find is (domain) data object models. The common object oriented approach is: data aka structure over functionality. This is true even for the most modern modeling approaches like Domain Driven Design. Look at the literature and what you find is recommendations on how to get data structures right: aggregates, entities, value objects. I´m not saying this is what object orientation was invented for. But I´m saying that´s what I happen to see across many teams now some 25 years after object orientation became mainstream through C++, Delphi, and Java. But why should we switch back? Because software development cannot become truly agile with a data focus. The reason for that lies in what customers need first: functionality, behavior, operations. To be clear, that´s not why software is built. The purpose of software is to be more efficient than the alternative. Money mainly is spent to get a certain level of quality (e.g. performance, scalability, security etc.). But without functionality being present, there is nothing to work on the quality of. What customers want is functionality of a certain quality. ASAP. And tomorrow new functionality needs to be added, existing functionality needs to be changed, and quality needs to be increased. No customer ever wanted data or structures. Of course data should be processed. Data is there, data gets generated, transformed, stored. But how the data is structured for this to happen efficiently is of no concern to the customer. Ask a customer (or user) whether she likes the data structured this way or that way. She´ll say, “I don´t care.” But ask a customer (or user) whether he likes the functionality and its quality this way or that way. He´ll say, “I like it” (or “I don´t like it”). Build software incrementally From this very natural focus of customers and users on functionality and its quality follows we should develop software incrementally. That´s what Agility is about. Deliver small increments quickly and often to get frequent feedback. That way less waste is produced, and learning can take place much easier (on the side of the customer as well as on the side of developers). An increment is some added functionality or quality of functionality.[1] So as it turns out, Agility is about functionality over whatever. But software developers’ thinking is still stuck in the object oriented mindset of whatever over functionality. Bummer. I guess that (at least partly) explains why Agility always hits a glass ceiling in projects. It´s a clash of mindsets, of cultures. Driving software development by demanding small increases in functionality runs against thinking about software as growing (data) structures sprinkled with functionality. (Excuse me, if this sounds a bit broad-brush. But you get my point.) The need for abstraction In the end there need to be data structures. Of course. Small and large ones. The phrase functionality over data does not deny that. It´s not functionality instead of data or something. It´s just over, i.e. functionality should be thought of first. It´s a tad more important. It´s what the customer wants. That´s why we need a way to design functionality. Small and large. We need to be able to think about functionality before implementing it. We need to be able to reason about it among team members. We need to be able to communicate our mental models of functionality not just by speaking about them, but also on paper. Otherwise reasoning about it does not scale. We learned thinking about functionality in the small using flow charts, Nassi-Shneiderman diagrams, pseudo code, or UML sequence diagrams. That´s nice and well. But it does not scale. You can use these tools to describe manageable algorithms. But it does not work for the functionality triggered by pressing the “1-Click Order” on an amazon product page for example. There are several reasons for that, I´d say. Firstly, the level of abstraction over code is negligible. It´s essentially non-existent. Drawing a flow chart or writing pseudo code or writing actual code is very, very much alike. All these tools are about control flow like code is.[2] In addition all tools are computationally complete. They are about logic which is expressions and especially control statements. Whatever you code in Java you can fully (!) describe using a flow chart. And then there is no data. They are about control flow and leave out the data altogether. Thus data mostly is assumed to be global. That´s shooting yourself in the foot, as I hope you agree. Even if it´s functionality over data that does not mean “don´t think about data”. Right to the contrary! Functionality only makes sense with regard to data. So data needs to be in the picture right from the start - but it must not dominate the thinking. The above tools fail on this. Bottom line: So far we´re unable to reason in a scalable and abstract manner about functionality. That´s why programmers are so driven to start coding once they are presented with a problem. Programming languages are the only tool they´ve learned to use to reason about functional solutions. Or, well, there might be exceptions. Mathematical notation and SQL may have come to your mind already. Indeed they are tools on a higher level of abstraction than flow charts etc. That´s because they are declarative and not computationally complete. They leave out details - in order to deliver higher efficiency in devising overall solutions. We can easily reason about functionality using mathematics and SQL. That´s great. Except for that they are domain specific languages. They are not general purpose. (And they don´t scale either, I´d say.) Bummer. So to be more precise we need a scalable general purpose tool on a higher than code level of abstraction not neglecting data. Enter: Flow Design. Abstracting functionality using data flows I believe the solution to the problem of abstracting functionality lies in switching from control flow to data flow. Data flow very naturally is not about logic details anymore. There are no expressions and no control statements anymore. There are not even statements anymore. Data flow is declarative by nature. With data flow we get rid of all the limiting traits of former approaches to modeling functionality. In addition, nomen est omen, data flows include data in the functionality picture. With data flows, data is visibly flowing from processing step to processing step. Control is not flowing. Control is wherever it´s needed to process data coming in. That´s a crucial difference and needs some rewiring in your head to be fully appreciated.[2] Since data flows are declarative they are not the right tool to describe algorithms, though, I´d say. With them you don´t design functionality on a low level. During design data flow processing steps are black boxes. They get fleshed out during coding. Data flow design thus is more coarse grained than flow chart design. It starts on a higher level of abstraction - but then is not limited. By nesting data flows indefinitely you can design functionality of any size, without losing sight of your data. Data flows scale very well during design. They can be used on any level of granularity. And they can easily be depicted. Communicating designs using data flows is easy and scales well, too. The result of functional design using data flows is not algorithms (too low level), but processes. Think of data flows as descriptions of industrial production lines. Data as material runs through a number of processing steps to be analyzed, enhances, transformed. On the top level of a data flow design might be just one processing step, e.g. “execute 1-click order”. But below that are arbitrary levels of flows with smaller and smaller steps. That´s not layering as in “layered architecture”, though. Rather it´s a stratified design à la Abelson/Sussman. Refining data flows is not your grandpa´s functional decomposition. That was rooted in control flows. Refining data flows does not suffer from the limits of functional decomposition against which object orientation was supposed to be an antidote. Summary I´ve been working exclusively with data flows for functional design for the past 4 years. It has changed my life as a programmer. What once was difficult is now easy. And, no, I´m not using Clojure or F#. And I´m not a async/parallel execution buff. Designing the functionality of increments using data flows works great with teams. It produces design documentation which can easily be translated into code - in which then the smallest data flow processing steps have to be fleshed out - which is comparatively easy. Using a systematic translation approach code can mirror the data flow design. That way later on the design can easily be reproduced from the code if need be. And finally, data flow designs play well with object orientation. They are a great starting point for class design. But that´s a story for another day. To me data flow design simply is one of the missing links of systematic lightweight software design. There are also other artifacts software development can produce to get feedback, e.g. process descriptions, test cases. But customers can be delighted more easily with code based increments in functionality. ? No, I´m not talking about the endless possibilities this opens for parallel processing. Data flows are useful independently of multi-core processors and Actor-based designs. That´s my whole point here. Data flows are good for reasoning and evolvability. So forget about any special frameworks you might need to reap benefits from data flows. None are necessary. Translating data flow designs even into plain of Java is possible. ?

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  • From HttpRuntime.Cache to Windows Azure Caching (Preview)

    - by Jeff
    I don’t know about you, but the announcement of Windows Azure Caching (Preview) (yes, the parentheses are apparently part of the interim name) made me a lot more excited about using Azure. Why? Because one of the great performance tricks of any Web app is to cache frequently used data in memory, so it doesn’t have to hit the database, a service, or whatever. When you run your Web app on one box, HttpRuntime.Cache is a sweet and stupid-simple solution. Somewhere in the data fetching pieces of your app, you can see if an object is available in cache, and return that instead of hitting the data store. I did this quite a bit in POP Forums, and it dramatically cuts down on the database chatter. The problem is that it falls apart if you run the app on many servers, in a Web farm, where one server may initiate a change to that data, and the others will have no knowledge of the change, making it stale. Of course, if you have the infrastructure to do so, you can use something like memcached or AppFabric to do a distributed cache, and achieve the caching flavor you desire. You could do the same thing in Azure before, but it would cost more because you’d need to pay for another role or VM or something to host the cache. Now, you can use a portion of the memory from each instance of a Web role to act as that cache, with no additional cost. That’s huge. So if you’re using a percentage of memory that comes out to 100 MB, and you have three instances running, that’s 300 MB available for caching. For the uninitiated, a Web role in Azure is essentially a VM that runs a Web app (worker roles are the same idea, only without the IIS part). You can spin up many instances of the role, and traffic is load balanced to the various instances. It’s like adding or removing servers to a Web farm all willy-nilly and at your discretion, and it’s what the cloud is all about. I’d say it’s my favorite thing about Windows Azure. The slightly annoying thing about developing for a Web role in Azure is that the local emulator that’s launched by Visual Studio is a little on the slow side. If you’re used to using the built-in Web server, you’re used to building and then alt-tabbing to your browser and refreshing a page. If you’re just changing an MVC view, you’re not even doing the building part. Spinning up the simulated Azure environment is too slow for this, but ideally you want to code your app to use this fantastic distributed cache mechanism. So first off, here’s the link to the page showing how to code using the caching feature. If you’re used to using HttpRuntime.Cache, this should be pretty familiar to you. Let’s say that you want to use the Azure cache preview when you’re running in Azure, but HttpRuntime.Cache if you’re running local, or in a regular IIS server environment. Through the magic of dependency injection, we can get there pretty quickly. First, design an interface to handle the cache insertion, fetching and removal. Mine looks like this: public interface ICacheProvider {     void Add(string key, object item, int duration);     T Get<T>(string key) where T : class;     void Remove(string key); } Now we’ll create two implementations of this interface… one for Azure cache, one for HttpRuntime: public class AzureCacheProvider : ICacheProvider {     public AzureCacheProvider()     {         _cache = new DataCache("default"); // in Microsoft.ApplicationServer.Caching, see how-to      }         private readonly DataCache _cache;     public void Add(string key, object item, int duration)     {         _cache.Add(key, item, new TimeSpan(0, 0, 0, 0, duration));     }     public T Get<T>(string key) where T : class     {         return _cache.Get(key) as T;     }     public void Remove(string key)     {         _cache.Remove(key);     } } public class LocalCacheProvider : ICacheProvider {     public LocalCacheProvider()     {         _cache = HttpRuntime.Cache;     }     private readonly System.Web.Caching.Cache _cache;     public void Add(string key, object item, int duration)     {         _cache.Insert(key, item, null, DateTime.UtcNow.AddMilliseconds(duration), System.Web.Caching.Cache.NoSlidingExpiration);     }     public T Get<T>(string key) where T : class     {         return _cache[key] as T;     }     public void Remove(string key)     {         _cache.Remove(key);     } } Feel free to expand these to use whatever cache features you want. I’m not going to go over dependency injection here, but I assume that if you’re using ASP.NET MVC, you’re using it. Somewhere in your app, you set up the DI container that resolves interfaces to concrete implementations (Ninject call is a “kernel” instead of a container). For this example, I’ll show you how StructureMap does it. It uses a convention based scheme, where if you need to get an instance of IFoo, it looks for a class named Foo. You can also do this mapping explicitly. The initialization of the container looks something like this: ObjectFactory.Initialize(x =>             {                 x.Scan(scan =>                         {                             scan.AssembliesFromApplicationBaseDirectory();                             scan.WithDefaultConventions();                         });                 if (Microsoft.WindowsAzure.ServiceRuntime.RoleEnvironment.IsAvailable)                     x.For<ICacheProvider>().Use<AzureCacheProvider>();                 else                     x.For<ICacheProvider>().Use<LocalCacheProvider>();             }); If you use Ninject or Windsor or something else, that’s OK. Conceptually they’re all about the same. The important part is the conditional statement that checks to see if the app is running in Azure. If it is, it maps ICacheProvider to AzureCacheProvider, otherwise it maps to LocalCacheProvider. Now when a request comes into your MVC app, and the chain of dependency resolution occurs, you can see to it that the right caching code is called. A typical design may have a call stack that goes: Controller –> BusinessLogicClass –> Repository. Let’s say your repository class looks like this: public class MyRepo : IMyRepo {     public MyRepo(ICacheProvider cacheProvider)     {         _context = new MyDataContext();         _cache = cacheProvider;     }     private readonly MyDataContext _context;     private readonly ICacheProvider _cache;     public SomeType Get(int someTypeID)     {         var key = "somename-" + someTypeID;         var cachedObject = _cache.Get<SomeType>(key);         if (cachedObject != null)         {             _context.SomeTypes.Attach(cachedObject);             return cachedObject;         }         var someType = _context.SomeTypes.SingleOrDefault(p => p.SomeTypeID == someTypeID);         _cache.Add(key, someType, 60000);         return someType;     } ... // more stuff to update, delete or whatever, being sure to remove // from cache when you do so  When the DI container gets an instance of the repo, it passes an instance of ICacheProvider to the constructor, which in this case will be whatever implementation was specified when the container was initialized. The Get method first tries to hit the cache, and of course doesn’t care what the underlying implementation is, Azure, HttpRuntime, or otherwise. If it finds the object, it returns it right then. If not, it hits the database (this example is using Entity Framework), and inserts the object into the cache before returning it. The important thing not pictured here is that other methods in the repo class will construct the key for the cached object, in this case “somename-“ plus the ID of the object, and then remove it from cache, in any method that alters or deletes the object. That way, no matter what instance of the role is processing the request, it won’t find the object if it has been made stale, that is, updated or outright deleted, forcing it to attempt to hit the database. So is this good technique? Well, sort of. It depends on how you use it, and what your testing looks like around it. Because of differences in behavior and execution of the two caching providers, for example, you could see some strange errors. For example, I immediately got an error indicating there was no parameterless constructor for an MVC controller, because the DI resolver failed to create instances for the dependencies it had. In reality, the NuGet packaged DI resolver for StructureMap was eating an exception thrown by the Azure components that said my configuration, outlined in that how-to article, was wrong. That error wouldn’t occur when using the HttpRuntime. That’s something a lot of people debate about using different components like that, and how you configure them. I kinda hate XML config files, and like the idea of the code-based approach above, but you should be darn sure that your unit and integration testing can account for the differences.

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  • Performance surprise with "as" and nullable types

    - by Jon Skeet
    I'm just revising chapter 4 of C# in Depth which deals with nullable types, and I'm adding a section about using the "as" operator, which allows you to write: object o = ...; int? x = o as int?; if (x.HasValue) { ... // Use x.Value in here } I thought this was really neat, and that it could improve performance over the C# 1 equivalent, using "is" followed by a cast - after all, this way we only need to ask for dynamic type checking once, and then a simple value check. This appears not to be the case, however. I've included a sample test app below, which basically sums all the integers within an object array - but the array contains a lot of null references and string references as well as boxed integers. The benchmark measures the code you'd have to use in C# 1, the code using the "as" operator, and just for kicks a LINQ solution. To my astonishment, the C# 1 code is 20 times faster in this case - and even the LINQ code (which I'd have expected to be slower, given the iterators involved) beats the "as" code. Is the .NET implementation of isinst for nullable types just really slow? Is it the additional unbox.any that causes the problem? Is there another explanation for this? At the moment it feels like I'm going to have to include a warning against using this in performance sensitive situations... Results: Cast: 10000000 : 121 As: 10000000 : 2211 LINQ: 10000000 : 2143 Code: using System; using System.Diagnostics; using System.Linq; class Test { const int Size = 30000000; static void Main() { object[] values = new object[Size]; for (int i = 0; i < Size - 2; i += 3) { values[i] = null; values[i+1] = ""; values[i+2] = 1; } FindSumWithCast(values); FindSumWithAs(values); FindSumWithLinq(values); } static void FindSumWithCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is int) { int x = (int) o; sum += x; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { int? x = o as int?; if (x.HasValue) { sum += x.Value; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithLinq(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = values.OfType<int>().Sum(); sw.Stop(); Console.WriteLine("LINQ: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } }

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  • PHP parsing XML file with and without namespaces

    - by Mike
    I need to get a XML File into a Database. Thats not the problem. Cant read it, parse it and create some Objects to map to the DB. Problem is, that sometimes the XML File can contain namespaces and sometimes not. Furtermore sometimes there is no namespace defined at all. So what i first got was something like this: <?xml version="1.0" encoding="UTF-8"?> <struct xmlns:b="http://www.w3schools.com/test/"> <objects> <object> <node_1>value1</node_1> <node_2>value2</node_2> <node_3 iso_land="AFG"/> <coords lat="12.00" long="13.00"/> </object> </objects> </struct> And the parsing: $t = $xml->xpath('/objects/object'); foreach($nodes AS $node) { if($t[0]->$node) { $obj->$node = (string) $t[0]->$node; } } Thats fine as long as there are no namespaces. Here comes the XML File with namespaces: <?xml version="1.0" encoding="UTF-8"?> <b:struct xmlns:b="http://www.w3schools.com/test/"> <b:objects> <b:object> <b:node_1>value1</b:node_1> <b:node_2>value2</b:node_2> <b:node_3 iso_land="AFG"/> <b:coords lat="12.00" long="13.00"/> </b:object> </b:objects> </b:struct> I now came up with something like this: $xml = simplexml_load_file("test.xml"); $namespaces = $xml->getNamespaces(TRUE); $ns = count($namespaces) ? 'a:' : ''; $xml->registerXPathNamespace("a", "http://www.w3schools.com/test/"); $nodes = array('node_1', 'node_2'); $obj = new stdClass(); foreach($nodes AS $node) { $t = $xml->xpath('/'.$ns.'objects/'.$ns.'object/'.$ns.$node); if($t[0]) { $obj->$node = (string) $t[0]; } } $t = $xml->xpath('/'.$ns.'objects/'.$ns.'object/'.$ns.'node_3'); if($t[0]) { $obj->iso_land = (string) $t[0]->attributes()->iso_land; } $t = $xml->xpath('/'.$ns.'objects/'.$ns.'object/'.$ns.'coords'); if($t[0]) { $obj->lat = (string) $t[0]->attributes()->lat; $obj->long = (string) $t[0]->attributes()->long; } That works with namespaces and without. But i feel that there must be a better way. Before that i could do something like this: $t = $xml->xpath('/'.$ns.'objects/'.$ns.'object'); foreach($nodes AS $node) { if($t[0]->$node) { $obj->$node = (string) $t[0]->$node; } } But that just wont work with namespaces.

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  • Creating a Serializable mock with Mockito error

    - by KwintenP
    I'm trying to create a mock object with Mockito that can be serialized. The object is an interface implementation. When this method is called, I receive an object that I want to pass to another object, hence using the doAnswer(...)-method. This is my code. InterfaceClass obj = mock(InterfaceClass.class, withSettings().serializable()); doAnswer(new Answer<Object>() { public Object answer(InvocationOnMock invocation) throws Throwable { Object[] args = invocation.getArguments(); //Here I do something with the arguments } }).when(obj).someMethod( any(someObject.class)); ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutput out = null; try { out = new ObjectOutputStream(bos); out.writeObject(obj); byte[] yourBytes = bos.toByteArray(); } finally { out.close(); bos.close(); } As far as I can tell this should be correct (I'm fairly new to Mockito). But when Serializing my object I get this error: java.io.NotSerializableException: com.trust1t.ocs.signcore.test.InvalidInputTestCase$1 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1165) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329) at java.util.concurrent.ConcurrentLinkedQueue.writeObject(ConcurrentLinkedQueue.java:644) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:950) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1482) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329) at java.util.LinkedList.writeObject(LinkedList.java:943) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:950) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1482) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329) at com.trust1t.ocs.signcore.test.InvalidInputTestCase.certificateValidationTest(InvalidInputTestCase.java:117) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) The invalidInputTestCase class is the class containing the test where I'm using this code. It looks as if the mock object references this TestCase somewhere (can't find it though). Am I not correctly implementing this or better ideas to mock?

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  • Cannot Display Chinese Character in my PHP code

    - by Jun1st
    I want to display my Twitter Info in my blog. So I write some code to get it. the issue I got is that Chinese characters displayed as unknown code. Here is the test code. Could anyone take a look and help? Thanks <html> <title>Twitter Test</title> <body> <?php function mystique_objectToArray($object){ if(!is_object($object) && !is_array($object)) return $object; if(is_object($object)) $object = get_object_vars($object); return array_map('mystique_objectToArray', $object); } define( 'ABSPATH', dirname(dirname(__FILE__)) . '/' ); require_once('/home/jun1st/jun1stfeng.com/wp-includes/class-snoopy.php'); $snoopy = new Snoopy; $response = @$snoopy->fetch("http://twitter.com/users/show/jun1st.json"); if ($response) $userdata = json_decode($snoopy->results, true); else $error = true; $response = @$snoopy->fetch("http://twitter.com/statuses/user_timeline/jun1st.json"); if ($response) $tweets = json_decode($snoopy->results, true); else $error = true; if(!$error): // for php < 5 (included JSON returns object) $userdata = mystique_objectToArray($userdata); $tweets = mystique_objectToArray($tweets); $twitdata = array(); $twitdata['user']['profile_image_url'] = $userdata['profile_image_url']; $twitdata['user']['name'] = $userdata['name']; $twitdata['user']['screen_name'] = $userdata['screen_name']; $twitdata['user']['followers_count'] = $userdata['followers_count']; $i = 0; foreach($tweets as $tweet): $twitdata['tweets'][$i]['text'] = $tweet['text']; $twitdata['tweets'][$i]['created_at'] = $tweet['created_at']; $twitdata['tweets'][$i]['id'] = $tweet['id']; $i++; endforeach; endif; // only show if the twitter data from the database is newer than 6 hours if(is_array($twitdata['tweets'])): ?> <div class="clear-block"> <div class="avatar"><img src="<?php echo $twitdata['user']['profile_image_url']; ?>" alt="<?php echo $twitdata['user']['name']; ?>" /></div> <div class="info"><a href="http://www.twitter.com/jun1st"><?php echo $twitdata['user']['name']; ?> </a><br /><span class="followers"> <?php printf(__("%s followers","mystique"),$twitdata['user']['followers_count']); ?></span></div> </div> <ul> <?php $i = 0; foreach($twitdata['tweets'] as $tweet): $pattern = '/\@(\w+)/'; $replace = '<a rel="nofollow" href="http://twitter.com/$1">@$1</a>'; $tweet['text'] = preg_replace($pattern, $replace , $tweet['text']); $tweet['text'] = make_clickable($tweet['text']); // remove +XXXX $tweettime = substr_replace($tweet['created_at'],'',strpos($tweet['created_at'],"+"),5); $link = "http://twitter.com/".$twitdata['user']['screen_name']."/statuses/".$tweet['id']; echo '<li><span class="entry">' . $tweet['text'] .'<a class="date" href="'.$link.'" rel="nofollow">'.$tweettime.'</a></span></li>'; $i++; if ($i == $twitcount) break; endforeach; ?> </ul> <? endif?> ?> </body> </html>

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  • How can I bind events to strongly typed datasets of different types?

    My application contains several forms which consist of a strongly typed datagridview, a strongly typed bindingsource, and a strongly typed table adapter. I am using some code in each form to update the database whenever the user leaves the current row, shifts focus away from the datagrid or the form, or closes the form. This code is the same in each case, so I want to make a subclass of form, from which all of these forms can inherit. But the strongly typed data objects all inherit from component, which doesn't expose the events I want to bind to or the methods I want to invoke. The only way I can see of gaining access to the events is to use: Type(string Name).GetEvent(string EventName).AddEventHandler(object Target,Delegate Handler) Similarly, I want to call the Update method of the strongly typed table adapter, and am using Type(string Name).GetMethod(String name, Type[] params).Invoke(object target, object[] params). It works ok, but it seems very heavy handed. Is there a better way? Here is my code for the main class: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows.Forms; using System.Data; using System.Data.SqlClient; using System.ComponentModel; namespace MyApplication { public class AutoSaveDataGridForm: Form { private DataRow PreviousRow; public Component Adapter { private get; set; } private Component dataGridView; public Component DataGridView { private get { return dataGridView; } set { dataGridView = value; Type t = dataGridView.GetType(); t.GetEvent("Leave").AddEventHandler(dataGridView, new EventHandler(DataGridView_Leave)); } } private Component bindingSource; public Component BindingSource { private get { return bindingSource; } set { bindingSource = value; Type t = bindingSource.GetType(); t.GetEvent("PositionChanged").AddEventHandler(bindingSource, new EventHandler(BindingSource_PositionChanged)); } } protected void Save() { if (PreviousRow != null && PreviousRow.RowState != DataRowState.Unchanged) { Type t = Adapter.GetType(); t.GetMethod("Update", new Type[] { typeof(DataRow[]) }).Invoke(Adapter, new object[] { new DataRow[] { PreviousRow } }); } } private void BindingSource_PositionChanged(object sender, EventArgs e) { BindingSource bindingSource = sender as BindingSource; DataRowView CurrentRowView = bindingSource.Current as DataRowView; DataRow CurrentRow = CurrentRowView.Row; if (PreviousRow != null && PreviousRow != CurrentRow) { Save(); } PreviousRow = CurrentRow; } private void InitializeComponent() { this.SuspendLayout(); // // AutoSaveDataGridForm // this.FormClosed += new System.Windows.Forms.FormClosedEventHandler(this.AutoSaveDataGridForm_FormClosed); this.Leave += new System.EventHandler(this.AutoSaveDataGridForm_Leave); this.ResumeLayout(false); } private void DataGridView_Leave(object sender, EventArgs e) { Save(); } private void AutoSaveDataGridForm_FormClosed(object sender, FormClosedEventArgs e) { Save(); } private void AutoSaveDataGridForm_Leave(object sender, EventArgs e) { Save(); } } } And here is a (partial) form which implements it: public partial class FileTypesInherited :AutoSaveDataGridForm { public FileTypesInherited() { InitializeComponent(); } private void FileTypesInherited_Load(object sender, EventArgs e) { // TODO: This line of code loads data into the 'sharedFoldersInformationV2DataSet.tblFileTypes' table. You can move, or remove it, as needed. this.tblFileTypesTableAdapter.Fill(this.sharedFoldersInformationV2DataSet.tblFileTypes); this.BindingSource = tblFileTypesBindingSource; this.Adapter = tblFileTypesTableAdapter; this.DataGridView = tblFileTypesDataGridView; } }

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  • globals and locals in python exec()

    - by hawkettc
    Hi, I'm trying to run a piece of python code using exec. my_code = """ class A(object): pass print 'locals: %s' % locals() print 'A: %s' % A class B(object): a_ref = A """ global_env = {} local_env = {} my_code_AST = compile(my_code, "My Code", "exec") exec(my_code_AST, global_env, local_env) print local_env which results in the following output locals: {'A': <class 'A'>} A: <class 'A'> Traceback (most recent call last): File "python_test.py", line 16, in <module> exec(my_code_AST, global_env, local_env) File "My Code", line 8, in <module> File "My Code", line 9, in B NameError: name 'A' is not defined However, if I change the code to this - my_code = """ class A(object): pass print 'locals: %s' % locals() print 'A: %s' % A class B(A): pass """ global_env = {} local_env = {} my_code_AST = compile(my_code, "My Code", "exec") exec(my_code_AST, global_env, local_env) print local_env then it works fine - giving the following output - locals: {'A': <class 'A'>} A: <class 'A'> {'A': <class 'A'>, 'B': <class 'B'>} Clearly A is present and accessible - what's going wrong in the first piece of code? I'm using 2.6.5, cheers, Colin * UPDATE 1 * If I check the locals() inside the class - my_code = """ class A(object): pass print 'locals: %s' % locals() print 'A: %s' % A class B(object): print locals() a_ref = A """ global_env = {} local_env = {} my_code_AST = compile(my_code, "My Code", "exec") exec(my_code_AST, global_env, local_env) print local_env Then it becomes clear that locals() is not the same in both places - locals: {'A': <class 'A'>} A: <class 'A'> {'__module__': '__builtin__'} Traceback (most recent call last): File "python_test.py", line 16, in <module> exec(my_code_AST, global_env, local_env) File "My Code", line 8, in <module> File "My Code", line 10, in B NameError: name 'A' is not defined However, if I do this, there is no problem - def f(): class A(object): pass class B(object): a_ref = A f() print 'Finished OK' * UPDATE 2 * ok, so the docs here - http://docs.python.org/reference/executionmodel.html 'A class definition is an executable statement that may use and define names. These references follow the normal rules for name resolution. The namespace of the class definition becomes the attribute dictionary of the class. Names defined at the class scope are not visible in methods.' It seems to me that 'A' should be made available as a free variable within the executable statement that is the definition of B, and this happens when we call f(), but not when we use exec(). This can be more easily shown with the following - my_code = """ class A(object): pass print 'locals in body: %s' % locals() print 'A: %s' % A def f(): print 'A in f: %s' % A f() class B(object): a_ref = A """ which outputs locals in body: {'A': <class 'A'>} A: <class 'A'> Traceback (most recent call last): File "python_test.py", line 20, in <module> exec(my_code_AST, global_env, local_env) File "My Code", line 11, in <module> File "My Code", line 9, in f NameError: global name 'A' is not defined So I guess the new question is - why aren't those locals being exposed as free variables in functions and class definitions - it seems like a pretty standard closure scenario.

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  • Java JNI leak in c++ process.

    - by user662056
    Hi all.. I am beginner in Java. My problem is: I am calling a Java class's method from c++. For this i am using JNI. Everythings works correct, but i have some memory LEAKS in the process of c++ program... So.. i did simple example.. 1) I create a java machine (jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);) 2) then i take a pointer on java class (jclass cls = env-FindClass("test_jni")); 3) after that i create a java class object object, by calling the constructor (testJavaObject = env-NewObject(cls, testConstruct);) AT THIS very moment in the process of c++ program is allocated 10 MB of memory 4) Next i delete the class , the object, and the Java Machine .. AT THIS very moment the 10 MB of memory are not free ................. So below i have a few lines of code c++ program void main() { { //Env JNIEnv *env; // java virtual machine JavaVM *jvm; JavaVMOption* options = new JavaVMOption[1]; //class paths options[0].optionString = "-Djava.class.path=C:/Sun/SDK/jdk/lib;D:/jms_test/java_jni_leak;"; // other options JavaVMInitArgs vm_args; vm_args.version = JNI_VERSION_1_6; vm_args.options = options; vm_args.nOptions = 1; vm_args.ignoreUnrecognized = false; // alloc part of memory (for test) before CreateJavaVM char* testMem0 = new char[1000]; for(int i = 0; i < 1000; ++i) testMem0[i] = 'a'; // create java VM jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args); // alloc part of memory (for test) after CreateJavaVM char* testMem1 = new char[1000]; for(int i = 0; i < 1000; ++i) testMem1[i] = 'b'; //Creating java virtual machine jclass cls = env->FindClass("test_jni"); // Id of a class constructor jmethodID testConstruct = env->GetMethodID(cls, "<init>", "()V"); // The Java Object // Calling the constructor, is allocated 10 MB of memory in c++ process jobject testJavaObject = env->NewObject(cls, testConstruct); // function DeleteLocalRef, // In this very moment memory not free env->DeleteLocalRef(testJavaObject); env->DeleteLocalRef(cls); // 1!!!!!!!!!!!!! res = jvm->DestroyJavaVM(); delete[] testMem0; delete[] testMem1; // In this very moment memory not free. TO /// } int gg = 0; } java class (it just allocs some memory) import java.util.*; public class test_jni { ArrayList<String> testStringList; test_jni() { System.out.println("start constructor"); testStringList = new ArrayList<String>(); for(int i = 0; i < 1000000; ++i) { // ??????? ?????? testStringList.add("TEEEEEEEEEEEEEEEEST"); } } } process memory view, after crating javaVM and java object: testMem0 and testMem1 - test memory, that's allocated by c++. ************** testMem0 ************** JNI_CreateJavaVM ************** testMem1 ************** // create java object jobject testJavaObject = env->NewObject(cls, testConstruct); ************** process memory view, after destroy javaVM and delete ref on java object: testMem0 and testMem1 are deleted to; ************** JNI_CreateJavaVM ************** // create java object jobject testJavaObject = env->NewObject(cls, testConstruct); ************** So testMem0 and testMem1 is deleted, But JavaVM and Java object not.... Sow what i do wrong... and how i can free memory in the c++ process program.

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  • CodePlex Daily Summary for Friday, May 07, 2010

    CodePlex Daily Summary for Friday, May 07, 2010New ProjectsBibleBrowser: BibleBrowserBibleMaps: BibleMapsChristianLibrary: ChristianLibraryCLB Podcast Module: DotNetNuke Module used to allow DNN to host one or more podcasts within a portal.Coletivo InVitro: Nova versão do Site do ColetivoCustomer Care Accelerator for Microsoft Dynamics CRM: Customer Care Accelerator for Microsoft Dynamics CRM.EasyTFS: A very lightweight, quick, web-based search application for Team Foundation Server. EasyTfs searches as you type, providing real-time search resul...FSCommunity: abcGeocache Downloader: GeocacheDownloader helps you download geocache information in an organised way, making easier to copy the information to your device. The applicati...Grabouille: Grabouille aims to be an incubation project for Microsoft best patterns & practices and also a container for last .Net technologies. The goal is, i...Klaverjas: Test application for testing different new technologies in .NET (WCF, DataServices, C# stuff, Entity...etc.)Livecity: Social network. Alpha 0.1MarxSupples: testMOSS 2007 - Excel Services: This helps you understand MOSS 2007 - Excel Services and how to use the same in .NETmy site: a personal web siteNazTek.Extension.Clr35: Contains a set of CLR 3.5 extensions and utility APInetDumbster: netDumbster is a .Net Fake SMTP Server clone of the popular Dumbster (http://quintanasoft.com/dumbster/) netDumbster is based on the API of nDumbs...Object-Oriented Optimization Toolbox (OOOT): A library (.dll) of various linear, nonlinear, and stochastic numerical optimization techniques. While some of these are older than 50 years, they ...OMap - Object to Object Mapper: OMap is a simple object to object mapper. 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  • C#/.NET Little Wonders: Constraining Generics with Where Clause

    - by James Michael Hare
    Back when I was primarily a C++ developer, I loved C++ templates.  The power of writing very reusable generic classes brought the art of programming to a brand new level.  Unfortunately, when .NET 1.0 came about, they didn’t have a template equivalent.  With .NET 2.0 however, we finally got generics, which once again let us spread our wings and program more generically in the world of .NET However, C# generics behave in some ways very differently from their C++ template cousins.  There is a handy clause, however, that helps you navigate these waters to make your generics more powerful. The Problem – C# Assumes Lowest Common Denominator In C++, you can create a template and do nearly anything syntactically possible on the template parameter, and C++ will not check if the method/fields/operations invoked are valid until you declare a realization of the type.  Let me illustrate with a C++ example: 1: // compiles fine, C++ makes no assumptions as to T 2: template <typename T> 3: class ReverseComparer 4: { 5: public: 6: int Compare(const T& lhs, const T& rhs) 7: { 8: return rhs.CompareTo(lhs); 9: } 10: }; Notice that we are invoking a method CompareTo() off of template type T.  Because we don’t know at this point what type T is, C++ makes no assumptions and there are no errors. C++ tends to take the path of not checking the template type usage until the method is actually invoked with a specific type, which differs from the behavior of C#: 1: // this will NOT compile! C# assumes lowest common denominator. 2: public class ReverseComparer<T> 3: { 4: public int Compare(T lhs, T rhs) 5: { 6: return lhs.CompareTo(rhs); 7: } 8: } So why does C# give us a compiler error even when we don’t yet know what type T is?  This is because C# took a different path in how they made generics.  Unless you specify otherwise, for the purposes of the code inside the generic method, T is basically treated like an object (notice I didn’t say T is an object). That means that any operations, fields, methods, properties, etc that you attempt to use of type T must be available at the lowest common denominator type: object.  Now, while object has the broadest applicability, it also has the fewest specific.  So how do we allow our generic type placeholder to do things more than just what object can do? Solution: Constraint the Type With Where Clause So how do we get around this in C#?  The answer is to constrain the generic type placeholder with the where clause.  Basically, the where clause allows you to specify additional constraints on what the actual type used to fill the generic type placeholder must support. You might think that narrowing the scope of a generic means a weaker generic.  In reality, though it limits the number of types that can be used with the generic, it also gives the generic more power to deal with those types.  In effect these constraints says that if the type meets the given constraint, you can perform the activities that pertain to that constraint with the generic placeholders. Constraining Generic Type to Interface or Superclass One of the handiest where clause constraints is the ability to specify the type generic type must implement a certain interface or be inherited from a certain base class. For example, you can’t call CompareTo() in our first C# generic without constraints, but if we constrain T to IComparable<T>, we can: 1: public class ReverseComparer<T> 2: where T : IComparable<T> 3: { 4: public int Compare(T lhs, T rhs) 5: { 6: return lhs.CompareTo(rhs); 7: } 8: } Now that we’ve constrained T to an implementation of IComparable<T>, this means that our variables of generic type T may now call any members specified in IComparable<T> as well.  This means that the call to CompareTo() is now legal. If you constrain your type, also, you will get compiler warnings if you attempt to use a type that doesn’t meet the constraint.  This is much better than the syntax error you would get within C++ template code itself when you used a type not supported by a C++ template. Constraining Generic Type to Only Reference Types Sometimes, you want to assign an instance of a generic type to null, but you can’t do this without constraints, because you have no guarantee that the type used to realize the generic is not a value type, where null is meaningless. Well, we can fix this by specifying the class constraint in the where clause.  By declaring that a generic type must be a class, we are saying that it is a reference type, and this allows us to assign null to instances of that type: 1: public static class ObjectExtensions 2: { 3: public static TOut Maybe<TIn, TOut>(this TIn value, Func<TIn, TOut> accessor) 4: where TOut : class 5: where TIn : class 6: { 7: return (value != null) ? accessor(value) : null; 8: } 9: } In the example above, we want to be able to access a property off of a reference, and if that reference is null, pass the null on down the line.  To do this, both the input type and the output type must be reference types (yes, nullable value types could also be considered applicable at a logical level, but there’s not a direct constraint for those). Constraining Generic Type to only Value Types Similarly to constraining a generic type to be a reference type, you can also constrain a generic type to be a value type.  To do this you use the struct constraint which specifies that the generic type must be a value type (primitive, struct, enum, etc). Consider the following method, that will convert anything that is IConvertible (int, double, string, etc) to the value type you specify, or null if the instance is null. 1: public static T? ConvertToNullable<T>(IConvertible value) 2: where T : struct 3: { 4: T? result = null; 5:  6: if (value != null) 7: { 8: result = (T)Convert.ChangeType(value, typeof(T)); 9: } 10:  11: return result; 12: } Because T was constrained to be a value type, we can use T? (System.Nullable<T>) where we could not do this if T was a reference type. Constraining Generic Type to Require Default Constructor You can also constrain a type to require existence of a default constructor.  Because by default C# doesn’t know what constructors a generic type placeholder does or does not have available, it can’t typically allow you to call one.  That said, if you give it the new() constraint, it will mean that the type used to realize the generic type must have a default (no argument) constructor. Let’s assume you have a generic adapter class that, given some mappings, will adapt an item from type TFrom to type TTo.  Because it must create a new instance of type TTo in the process, we need to specify that TTo has a default constructor: 1: // Given a set of Action<TFrom,TTo> mappings will map TFrom to TTo 2: public class Adapter<TFrom, TTo> : IEnumerable<Action<TFrom, TTo>> 3: where TTo : class, new() 4: { 5: // The list of translations from TFrom to TTo 6: public List<Action<TFrom, TTo>> Translations { get; private set; } 7:  8: // Construct with empty translation and reverse translation sets. 9: public Adapter() 10: { 11: // did this instead of auto-properties to allow simple use of initializers 12: Translations = new List<Action<TFrom, TTo>>(); 13: } 14:  15: // Add a translator to the collection, useful for initializer list 16: public void Add(Action<TFrom, TTo> translation) 17: { 18: Translations.Add(translation); 19: } 20:  21: // Add a translator that first checks a predicate to determine if the translation 22: // should be performed, then translates if the predicate returns true 23: public void Add(Predicate<TFrom> conditional, Action<TFrom, TTo> translation) 24: { 25: Translations.Add((from, to) => 26: { 27: if (conditional(from)) 28: { 29: translation(from, to); 30: } 31: }); 32: } 33:  34: // Translates an object forward from TFrom object to TTo object. 35: public TTo Adapt(TFrom sourceObject) 36: { 37: var resultObject = new TTo(); 38:  39: // Process each translation 40: Translations.ForEach(t => t(sourceObject, resultObject)); 41:  42: return resultObject; 43: } 44:  45: // Returns an enumerator that iterates through the collection. 46: public IEnumerator<Action<TFrom, TTo>> GetEnumerator() 47: { 48: return Translations.GetEnumerator(); 49: } 50:  51: // Returns an enumerator that iterates through a collection. 52: IEnumerator IEnumerable.GetEnumerator() 53: { 54: return GetEnumerator(); 55: } 56: } Notice, however, you can’t specify any other constructor, you can only specify that the type has a default (no argument) constructor. Summary The where clause is an excellent tool that gives your .NET generics even more power to perform tasks higher than just the base "object level" behavior.  There are a few things you cannot specify with constraints (currently) though: Cannot specify the generic type must be an enum. Cannot specify the generic type must have a certain property or method without specifying a base class or interface – that is, you can’t say that the generic must have a Start() method. Cannot specify that the generic type allows arithmetic operations. Cannot specify that the generic type requires a specific non-default constructor. In addition, you cannot overload a template definition with different, opposing constraints.  For example you can’t define a Adapter<T> where T : struct and Adapter<T> where T : class.  Hopefully, in the future we will get some of these things to make the where clause even more useful, but until then what we have is extremely valuable in making our generics more user friendly and more powerful!   Technorati Tags: C#,.NET,Little Wonders,BlackRabbitCoder,where,generics

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  • Developing Schema Compare for Oracle (Part 2): Dependencies

    - by Simon Cooper
    In developing Schema Compare for Oracle, one of the issues we came across was the size of the databases. As detailed in my last blog post, we had to allow schema pre-filtering due to the number of objects in a standard Oracle database. Unfortunately, this leads to some quite tricky situations regarding object dependencies. This post explains how we deal with these dependencies. 1. Cross-schema dependencies Say, in the following database, you're populating SchemaA, and synchronizing SchemaA.Table1: SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(Col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100) REFERENCES SchemaB.Table1(Col1)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100) PRIMARY KEY); We need to do a rebuild of SchemaA.Table1 to change Col1 from a VARCHAR2(100) to a NUMBER. This consists of: Creating a table with the new schema Inserting data from the old table to the new table, with appropriate conversion functions (in this case, TO_NUMBER) Dropping the old table Rename new table to same name as old table Unfortunately, in this situation, the rebuild will fail at step 1, as we're trying to create a NUMBER column with a foreign key reference to a VARCHAR2(100) column. As we're only populating SchemaA, the naive implementation of the object population prefiltering (sticking a WHERE owner = 'SCHEMAA' on all the data dictionary queries) will generate an incorrect sync script. What we actually have to do is: Drop foreign key constraint on SchemaA.Table1 Rebuild SchemaB.Table1 Rebuild SchemaA.Table1, adding the foreign key constraint to the new table This means that in order to generate a correct synchronization script for SchemaA.Table1 we have to know what SchemaB.Table1 is, and that it also needs to be rebuilt to successfully rebuild SchemaA.Table1. SchemaB isn't the schema that the user wants to synchronize, but we still have to load the table and column information for SchemaB.Table1 the same way as any table in SchemaA. Fortunately, Oracle provides (mostly) complete dependency information in the dictionary views. Before we actually read the information on all the tables and columns in the database, we can get dependency information on all the objects that are either pointed at by objects in the schemas we’re populating, or point to objects in the schemas we’re populating (think about what would happen if SchemaB was being explicitly populated instead), with a suitable query on all_constraints (for foreign key relationships) and all_dependencies (for most other types of dependencies eg a function using another function). The extra objects found can then be included in the actual object population, and the sync wizard then has enough information to figure out the right thing to do when we get to actually synchronize the objects. Unfortunately, this isn’t enough. 2. Dependency chains The solution above will only get the immediate dependencies of objects in populated schemas. What if there’s a chain of dependencies? A.tbl1 -> B.tbl1 -> C.tbl1 -> D.tbl1 If we’re only populating SchemaA, the implementation above will only include B.tbl1 in the dependent objects list, whereas we might need to know about C.tbl1 and D.tbl1 as well, in order to ensure a modification on A.tbl1 can succeed. What we actually need is a graph traversal on the dependency graph that all_dependencies represents. Fortunately, we don’t have to read all the database dependency information from the server and run the graph traversal on the client computer, as Oracle provides a method of doing this in SQL – CONNECT BY. So, we can put all the dependencies we want to include together in big bag with UNION ALL, then run a SELECT ... CONNECT BY on it, starting with objects in the schema we’re populating. We should end up with all the objects that might be affected by modifications in the initial schema we’re populating. Good solution? Well, no. For one thing, it’s sloooooow. all_dependencies, on my test databases, has got over 110,000 rows in it, and the entire query, for which Oracle was creating a temporary table to hold the big bag of graph edges, was often taking upwards of two minutes. This is too long, and would only get worse for large databases. But it had some more fundamental problems than just performance. 3. Comparison dependencies Consider the following schema: SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100)); What will happen if we used the dependency algorithm above on the source & target database? Well, SchemaA.Table1 has a foreign key reference to SchemaB.Table1, so that will be included in the source database population. On the target, SchemaA.Table1 has no such reference. Therefore SchemaB.Table1 will not be included in the target database population. In the resulting comparison of the two objects models, what you will end up with is: SOURCE  TARGET SchemaA.Table1 -> SchemaA.Table1 SchemaB.Table1 -> (no object exists) When this comparison is synchronized, we will see that SchemaB.Table1 does not exist, so we will try the following sequence of actions: Create SchemaB.Table1 Rebuild SchemaA.Table1, with foreign key to SchemaB.Table1 Oops. Because the dependencies are only followed within a single database, we’ve tried to create an object that already exists. To fix this we can include any objects found as dependencies in the source or target databases in the object population of both databases. SchemaB.Table1 will then be included in the target database population, and we won’t try and create objects that already exist. All good? Well, consider the following schema (again, only explicitly populating SchemaA, and synchronizing SchemaA.Table1): SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100) PRIMARY KEY); CREATE TABLE SchemaC.Table1 ( Col1 NUMBER);   CREATE TABLE SchemaC.Table1 ( Col1 VARCHAR2(100) REFERENCES SchemaB.Table1); Although we’re now including SchemaB.Table1 on both sides of the comparison, there’s a third table (SchemaC.Table1) that we don’t know about that will cause the rebuild of SchemaB.Table1 to fail if we try and synchronize SchemaA.Table1. That’s because we’re only running the dependency query on the schemas we’re explicitly populating; to solve this issue, we would have to run the dependency query again, but this time starting the graph traversal from the objects found in the other database. Furthermore, this dependency chain could be arbitrarily extended.This leads us to the following algorithm for finding all the dependencies of a comparison: Find initial dependencies of schemas the user has selected to compare on the source and target Include these objects in both the source and target object populations Run the dependency query on the source, starting with the objects found as dependents on the target, and vice versa Repeat 2 & 3 until no more objects are found For the schema above, this will result in the following sequence of actions: Find initial dependenciesSchemaA.Table1 -> SchemaB.Table1 found on sourceNo objects found on target Include objects in both source and targetSchemaB.Table1 included in source and target Run dependency query, starting with found objectsNo objects to start with on sourceSchemaB.Table1 -> SchemaC.Table1 found on target Include objects in both source and targetSchemaC.Table1 included in source and target Run dependency query on found objectsNo objects found in sourceNo objects to start with in target Stop This will ensure that we include all the necessary objects to make any synchronization work. However, there is still the issue of query performance; the CONNECT BY on the entire database dependency graph is still too slow. After much sitting down and drawing complicated diagrams, we decided to move the graph traversal algorithm from the server onto the client (which turned out to run much faster on the client than on the server); and to ensure we don’t read the entire dependency graph onto the client we also pull the graph across in bits – we start off with dependency edges involving schemas selected for explicit population, and whenever the graph traversal comes across a dependency reference to a schema we don’t yet know about a thunk is hit that pulls in the dependency information for that schema from the database. We continue passing more dependent objects back and forth between the source and target until no more dependency references are found. This gives us the list of all the extra objects to populate in the source and target, and object population can then proceed. 4. Object blacklists and fast dependencies When we tested this solution, we were puzzled in that in some of our databases most of the system schemas (WMSYS, ORDSYS, EXFSYS, XDB, etc) were being pulled in, and this was increasing the database registration and comparison time quite significantly. After debugging, we discovered that the culprits were database tables that used one of the Oracle PL/SQL types (eg the SDO_GEOMETRY spatial type). These were creating a dependency chain from the database tables we were populating to the system schemas, and hence pulling in most of the system objects in that schema. To solve this we introduced blacklists of objects we wouldn’t follow any dependency chain through. As well as the Oracle-supplied PL/SQL types (MDSYS.SDO_GEOMETRY, ORDSYS.SI_COLOR, among others) we also decided to blacklist the entire PUBLIC and SYS schemas, as any references to those would likely lead to a blow up in the dependency graph that would massively increase the database registration time, and could result in the client running out of memory. Even with these improvements, each dependency query was taking upwards of a minute. We discovered from Oracle execution plans that there were some columns, with dependency information we required, that were querying system tables with no indexes on them! To cut a long story short, running the following query: SELECT * FROM all_tab_cols WHERE data_type_owner = ‘XDB’; results in a full table scan of the SYS.COL$ system table! This single clause was responsible for over half the execution time of the dependency query. Hence, the ‘Ignore slow dependencies’ option was born – not querying this and a couple of similar clauses to drastically speed up the dependency query execution time, at the expense of producing incorrect sync scripts in rare edge cases. Needless to say, along with the sync script action ordering, the dependency code in the database registration is one of the most complicated and most rewritten parts of the Schema Compare for Oracle engine. The beta of Schema Compare for Oracle is out now; if you find a bug in it, please do tell us so we can get it fixed!

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