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  • Using Freepascal\Lazarus JSON Libraries

    - by Gizmo_the_Great
    I'm hoping for a bit of a "simpletons" demo\explanation for using Lazarus\Freepascal JSON parsing. I've asked a question here but all the replies are "read this" and none of them are really helping me get a grasp because the examples are bit too in-depth and I'm seeking a very simple example to help me understand how it works. In brief, my program reads an untyped binary file in chunks of 4096 bytes. The raw data then gets converted to ASCII and stored in a string. It then goes through the variable looking for certain patterns, which, it turned out, are JSON data structures. I've currently coded the parsing the hard way using Pos and ExtractANSIString etc. But I'vesince learnt that there are JSON libraries for Lazarus & FPC, namely fcl-json, fpjson, jsonparser, jsonscanner etc. https://bitbucket.org/reiniero/fpctwit/src http://fossies.org/unix/misc/fpcbuild-2.6.0.tar.gz:a/fpcbuild-2.6.0/fpcsrc/packages/fcl-json/src/ http://svn.freepascal.org/cgi-bin/viewvc.cgi/trunk/packages/fcl-json/examples/ However, I still can't quite work out HOW I read my string variable and parse it for JSON data and then access those JSON structures. Can anyone give me a very simple example, to help getting me going? My code so far (without JSON) is something like this: try SourceFile.Position := 0; while TotalBytesRead < SourceFile.Size do begin BytesRead := SourceFile.Read(Buffer,sizeof(Buffer)); inc(TotalBytesRead, BytesRead); StringContent := StripNonAsciiExceptCRLF(Buffer); // A custom function to strip out binary garbage leaving just ASCII readable text if Pos('MySearchValue', StringContent) > 0 then begin // Do the parsing. This is where I need to do the JSON stuff ...

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  • Access Violation Exception when trying to perform WTSVirtualChannelRead

    - by Scott Chamberlain
    I am trying to write a hello world type program for using virtual channels in the windows terminal services client. public partial class Form1 : Form { public Form1() { InitializeComponent(); } IntPtr mHandle = IntPtr.Zero; private void Form1_Load(object sender, EventArgs e) { mHandle = NativeMethods.WTSVirtualChannelOpen(IntPtr.Zero, -1, "TSCRED"); } private void button1_Click(object sender, EventArgs e) { int bufferSize = 1024; byte[] buffer = new byte[bufferSize]; int bytesRead = 0; NativeMethods.WTSVirtualChannelRead(mHandle, 0, buffer, bufferSize, ref bytesRead); if (bytesRead != 0) { MessageBox.Show("Got no Data"); } else { MessageBox.Show("Got data: " + bytesRead); } } protected override void Dispose(bool disposing) { if (mHandle != System.IntPtr.Zero) { NativeMethods.WTSVirtualChannelClose(mHandle); } base.Dispose(disposing); } } internal static class NativeMethods { [DllImport("Wtsapi32.dll")] public static extern IntPtr WTSVirtualChannelOpen(IntPtr server, int sessionId, [MarshalAs(UnmanagedType.LPStr)] string virtualName); [DllImport("Wtsapi32.dll", SetLastError = true)] public static extern bool WTSVirtualChannelRead(IntPtr channelHandle, long timeout, byte[] buffer, int length, ref int bytesReaded); [DllImport("Wtsapi32.dll")] public static extern bool WTSVirtualChannelClose(IntPtr channelHandle); } On NativeMethods.WTSVirtualChannelRead(mHandle, 0, buffer, bufferSize, ref bytesRead); I get the following error every time. System.AccessViolationException was unhandled by user code Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt. Source=RemoteForm StackTrace: at RemoteForm.NativeMethods.WTSVirtualChannelRead(IntPtr channelHandle, Int64 timeout, Byte[] buffer, Int32 length, Int32& bytesReaded) at RemoteForm.Form1.button1_Click(Object sender, EventArgs e) in E:\Visual Studio 2010\Projects\RemoteForm\Form1.cs:line 31 at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.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.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) InnerException: I am sending the data from the MSTSC COM object and ActiveX controll. public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { rdp.Server = "schamberlainvm"; rdp.UserName = "TestAcct"; IMsTscNonScriptable secured = (IMsTscNonScriptable)rdp.GetOcx(); secured.ClearTextPassword = "asdf"; rdp.CreateVirtualChannels("TSCRED"); rdp.Connect(); } private void button1_Click(object sender, EventArgs e) { rdp.SendOnVirtualChannel("TSCRED", "This is a test"); } } //Designer code // // rdp // this.rdp.Enabled = true; this.rdp.Location = new System.Drawing.Point(12, 12); this.rdp.Name = "rdp"; this.rdp.OcxState = ((System.Windows.Forms.AxHost.State)(resources.GetObject("rdp.OcxState"))); this.rdp.Size = new System.Drawing.Size(1092, 580); this.rdp.TabIndex = 0; Any help on this would be greatly appreciated.

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  • Efficient Context-Free Grammar parser, preferably Python-friendly

    - by Max Shawabkeh
    I am in need of parsing a small subset of English for one of my project, described as a context-free grammar with (1-level) feature structures (example) and I need to do it efficiently . Right now I'm using NLTK's parser which produces the right output but is very slow. For my grammar of ~450 fairly ambiguous non-lexicon rules and half a million lexical entries, parsing simple sentences can take anywhere from 2 to 30 seconds, depending it seems on the number of resulting trees. Lexical entries have little to no effect on performance. Another problem is that loading the (25MB) grammar+lexicon at the beginning can take up to a minute. From what I can find in literature, the running time of the algorithm used to parse such a grammar (Earley or CKY) should be linear to the size of the grammar and cubic to the size of the input token list. My experience with NLTK indicates that ambiguity is what hurts the performance most, not the absolute size of the grammar. So now I'm looking for a CFG parser to replace NLTK. I've been considering PLY but I can't tell whether it supports feature structures in CFGs, which are required in my case, and the examples I've seen seem to be doing a lot of procedural parsing rather than just specifying a grammar. Can anybody show me an example of PLY both supporting feature structs and using a declarative grammar? I'm also fine with any other parser that can do what I need efficiently. A Python interface is preferable but not absolutely necessary.

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  • Recommended way to test ActiveRecord associations?

    - by Sugerman
    I have written my basic models and defined their associations as well as the migrations to create the associated tables. I want to be able to test: The associations are configured as intended The table structures support the associations properly I've written FG factories for all of my models in anticipation of having a complete set of test data but I can't grasp how to write a spec to test both belongs_to and has_many associations. For example, given an Organization that has_many Users I want to be able to test that my sample Organization has a reference to my sample User. Organization_Factory.rb: Factory.define :boardofrec, :class => 'Organization' do |o| o.name 'Board of Recreation' o.address '115 Main Street' o.city 'Smallville' o.state 'New Jersey' o.zip '01929' end Factory.define :boardofrec_with_users, :parent => :boardofrec do |o| o.after_create do |org| org.users = [Factory.create(:johnny, :organization => org)] end end User_Factory.rb: Factory.define :johnny, :class => 'User' do |u| u.name 'Johnny B. Badd' u.email '[email protected]' u.password 'password' u.org_admin true u.site_admin false u.association :organization, :factory => :boardofrec end Organization_spec.rb: ... it "should have the user Johnny B. Badd" do boardofrec_with_users = Factory.create(:boardofrec_with_users) boardofrec_with_users.users.should include(Factory.create(:johnny)) end ... This example fails because the Organization.users list and the comparison User :johnny are separate instances of the same Factory. I realize this doesn't follow the BDD ideas behind what these plugins (FG, rspec) seemed to be geared for but seeing as this is my first rails application I'm uncomfortable moving forward without knowing that I've configured my associations and table structures properly.

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  • Cache efficient code

    - by goldenmean
    This could sound a subjective question, but what i am looking for is specific instances which you would have encountered related to this. 1) How to make a code, cache effective-cache friendly? (More cache hits, as less cahce misses as possible). from both perspectives, data cache & program cache(instruction cache). i.e. What all things in one's code, related to data structures, code constructs one should take care of to make it cache effective. 2) Are there any particular data structures one must use, must avoid,or particular way of accessing the memers of that structure etc.. to make code cache effective. 3) Are there any program constructs(if, for, switch, break, goto,...), code-flow(for inside a if, if inside a for, etc...) one should follow/avoid in this matter? I am looking forward to hear individual experiences related to making a cache efficient code in general. It can be any programming language(C,C++,ASsembly,...), any hardware target(ARM,Intel,PowerPC,...), any OS(Windows,Linux,Symbian,...) etc.. More the variety, it will help better to understand it deeply.

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  • Recommended ASP.NET Shared Hosting (USA)

    - by coffeeaddict
    Ok, I have to admit I'm getting fed up with www.discountasp.net's pricing model and this annoyance has built up over the past 8 years or so. I've been with them for years and absolutely love them on the technical side, however it's getting ridiculously expensive for so little that you get. I mean here's my scenario: 1) I am running 2 SQL Server databases which costs me $10/ea per month so that's $20/month for 2 and I only get 500 mb disk space which is horrible 2) I am paying $10/mo just for the hosting itself which I only get 1 gig of disk space! I mean common! 3) I am simply running 2 small apps (Screwturn Wiki & Subtext Blog)...so I don't really care if it's up 99% or not, it's not worth paying a total of $300 just to keep these 2 apps running over discountasp.net Anyone else feel the same? Yes, I know they have great support, probably have great servers running behind this but in the end I really don't care as long as my site is up 95% or better. Yes, the hosting toolset rocks. But you know I bet you I can find a similar set somewhere else. I like how I can totally control IIS 7 at discountasp and I can control my own app pool etc. That's very powerful and essential. But anyone have any good alternatives to discountasp that gives me close to the same at a much more reasonable cost point? I mean http://www.m6.net/prices.aspx gives you 10 SQL Databases for $7 and 200 gigs disk space! I don't know about their tools or support but just looking at those numbers and some other hosts I've seen, I feel that discountasp.net is way out of line. They don't even offer any purchasing discounts such as it would be nice if my 2nd SQL Server is only $5/month not $10...stuff like this, to make it much more realistic and fair. Opinions (people who do have discountasp.net, people who have left them, or people who have another host they like)??? But geez $300 just to host a couple DBs and lightweight open source apps? Not worth the price they are charging. I'm almost at a price point that enables me to get a decent dedicated server! I really don't care about beta ASP.NET frameworks support. Not a big deal to me. If you have alternative suggestions rather than your experience with discountasp, I'd like to know how their toolset is. Do you have complete control over your DB in terms of adding users, and same goes for the web app pool, etc.? Discountasp.net's control panel rocks. I don't want to loose the ability to at least control and add virtual directories, recycle my dedicated app pool myself, backup my sql database myself, through tools which is what discountasp does give you. I'd also want to know that the hoster at least gets the latest and greatest in terms of non-beta ASP.NET related frameworks available to its shared hosters.

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  • .NET Exception error, what does this error means?

    - by gsvirdi
    I've tried to develop a simple winform utility which is using xml file as its database. I've used VS 2008 express edition, C#. When this utility tries to write into the xml file then this error is displayed on other computer. I've tried to provide System.Xml.dll & System.Xml.Linq.dll in the same folder on the other computer but no use. What does it means? Any solution? See the end of this message for details on invoking just-in-time (JIT) debugging instead of this dialog box. ************** Exception Text ************** System.MissingMethodException: Method not found: 'Void System.Xml.XmlReaderSettings.set_MaxCharactersFromEntities(Int64)'. at System.Xml.Linq.XNode.GetXmlReaderSettings(LoadOptions o) at System.Xml.Linq.XDocument.Load(String uri, LoadOptions options) at System.Xml.Linq.XDocument.Load(String uri) at Issues.Form1.button1_Click(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.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.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) ************** Loaded Assemblies ************** mscorlib Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll ---------------------------------------- Issues Assembly Version: 1.0.0.0 Win32 Version: 1.0.0.0 CodeBase: file:///C:/Documents%20and%20Settings/sumsnl.LTSLFBD/Desktop/Process%20Improvement/Issues%20Register/Issues.exe ---------------------------------------- System.Windows.Forms Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll ---------------------------------------- System Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll ---------------------------------------- System.Drawing Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll ---------------------------------------- System.Xml Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll ---------------------------------------- System.Configuration Assembly Version: 2.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll ---------------------------------------- 4u_pgrmq Assembly Version: 1.0.0.0 Win32 Version: 2.0.50727.832 (QFE.050727-8300) CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll ---------------------------------------- ************** JIT Debugging ************** To enable just-in-time (JIT) debugging, the .config file for this application or computer (machine.config) must have the jitDebugging value set in the system.windows.forms section. The application must also be compiled with debugging enabled. For example: <configuration> <system.windows.forms jitDebugging="true" /> </configuration> When JIT debugging is enabled, any unhandled exception will be sent to the JIT debugger registered on the computer rather than be handled by this dialog box.

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  • Custom UserControl property not being set via XAML DataBinding in Silverlight 4

    - by programatique
    I have a custom user control called GoalProgressControl. Another user control contains GoalProgressControl and sets its GoalName attribute via databinding in XAML. However, the GoalName property is never set. When I check it in debug mode GoalName remains "null" for the control's lifetime. How do I set the GoalName property? Is there something I am doing incorrectly? I am using .NET Framework 4 and Silverlight 4. I am relatively new to XAML and Silverlight so any help would be greatly appreciated. I have attempted to change GoalProgressControl.GoalName into a POCO property but this causes a Silverlight error, and my reading leads me to believe that databound properties should be of type DependencyProperty. I've also simplified my code to just focus on the GoalName property (the code is below) with no success. Here is GoalProgressControl.xaml: <UserControl x:Class="GoalView.GoalProgressControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" DataContext="{Binding RelativeSource={RelativeSource Self}}" Height="100"> <Border Margin="5" Padding="5" BorderBrush="#999" BorderThickness="1"> <TextBlock Text="{Binding GoalName}"/> </Border> </UserControl> GoalProgressControl.xaml.cs: public partial class GoalProgressControl : UserControl, INotifyPropertyChanged { public GoalProgressControl() { InitializeComponent(); } public event PropertyChangedEventHandler PropertyChanged; public void NotifyPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public static DependencyProperty GoalNameProperty = DependencyProperty.Register("GoalName", typeof(string), typeof(GoalProgressControl), null); public string GoalName { get { return (String)GetValue(GoalProgressControl.GoalNameProperty); } set { base.SetValue(GoalProgressControl.GoalNameProperty, value); NotifyPropertyChanged("GoalName"); } } } I've placed GoalProgressControl on another page: <Grid Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2" Margin="5" Background="#eee" Height="200"> <Border BorderBrush="#999" BorderThickness="1" Background="White"> <StackPanel> <hgc:SectionTitleBar x:Name="ttlGoals" Title="Personal Goals" ImageSource="../Images/check.png" Uri="/Pages/GoalPage.xaml" MoreVisibility="Visible" /> <ItemsControl ItemsSource="{Binding Path=GoalItems}"> <ItemsControl.ItemTemplate> <DataTemplate> <!--TextBlock Text="{Binding Path=[Name]}"/--> <goal:GoalProgressControl GoalName="{Binding Path=[Name]}"/> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </StackPanel> </Border> </Grid> Please note the commented out "TextBlock" item above. If I comment in the TextBlock and comment out the GoalProgressControl, the binding works correctly and the TextBlock shows the GoalName correctly. Also, if I replace the "GoalName" property above with a simple text string (ex "hello world"), the control renders correctly and "hello world" is shown on the control when it renders.

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  • SharePoint: Problem with BaseFieldControl

    - by Anoop
    Hi All, In below code in a Gird First column is BaseFieldControl from a column of type Choice of SPList. Secound column is a text box control with textchange event. Both the controls are created at rowdatabound event of gridview. Now the problem is that when Steps: 1) select any of the value from BaseFieldControl(DropDownList) which is rendered from Choice Column of SPList 2) enter any thing in textbox in another column of grid. 3) textchanged event fires up and in textchange event rebound the grid. Problem: the selected value becomes the first item or the default value(if any). but if i do not rebound the grid at text changed event it works fine. Please suggest what to do. using System; using Microsoft.SharePoint; using Microsoft.SharePoint.WebControls; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; namespace SharePointProjectTest.Layouts.SharePointProjectTest { public partial class TestBFC : LayoutsPageBase { GridView grid = null; protected void Page_Load(object sender, EventArgs e) { try { grid = new GridView(); grid.ShowFooter = true; grid.ShowHeader = true; grid.AutoGenerateColumns = true; grid.ID = "grdView"; grid.RowDataBound += new GridViewRowEventHandler(grid_RowDataBound); grid.Width = Unit.Pixel(900); MasterPage holder = (MasterPage)Page.Controls[0]; holder.FindControl("PlaceHolderMain").Controls.Add(grid); DataTable ds = new DataTable(); ds.Columns.Add("Choice"); //ds.Columns.Add("person"); ds.Columns.Add("Curr"); for (int i = 0; i < 3; i++) { DataRow dr = ds.NewRow(); ds.Rows.Add(dr); } grid.DataSource = ds; grid.DataBind(); } catch (Exception ex) { } } void tx_TextChanged(object sender, EventArgs e) { DataTable ds = new DataTable(); ds.Columns.Add("Choice"); ds.Columns.Add("Curr"); for (int i = 0; i < 3; i++) { DataRow dr = ds.NewRow(); ds.Rows.Add(dr); } grid.DataSource = ds; grid.DataBind(); } void grid_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.DataRow) { SPWeb web = SPContext.Current.Web; SPList list = web.Lists["Source for test"]; SPField field = list.Fields["Choice"]; SPListItem item=list.Items.Add(); BaseFieldControl control = (BaseFieldControl)GetSharePointControls(field, list, item, SPControlMode.New); if (control != null) { e.Row.Cells[0].Controls.Add(control); } TextBox tx = new TextBox(); tx.AutoPostBack = true; tx.ID = "Curr"; tx.TextChanged += new EventHandler(tx_TextChanged); e.Row.Cells[1].Controls.Add(tx); } } public static Control GetSharePointControls(SPField field, SPList list, SPListItem item, SPControlMode mode) { if (field == null || field.FieldRenderingControl == null || field.Hidden) return null; try { BaseFieldControl webControl = field.FieldRenderingControl; webControl.ListId = list.ID; webControl.ItemId = item.ID; webControl.FieldName = field.Title; webControl.ID = "id_" + field.InternalName; webControl.ControlMode = mode; webControl.EnableViewState = true; return webControl; } catch (Exception ex) { return null; } } } }

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  • .NET - A way to add my own clipboard format to existing formats

    - by A9S6
    I have a Excel addin that displays some structures on the worksheet. Users can copy the structures and paste them in another worksheet or another application which is handled by the Clipboard formats. When a user copies the structure, I convert the structure into a specific format and put it on the clipboard using the DataObject::SetData(). Please note that when a copy is initiated in Excel, it puts a number of formats on the clipboard (see image). The problem is that there is a third party application that depends on the data on the clipboard(Copy from Excel and paste into this 3rd party app) but the funny thing is that I am not sure which format it depends on. I need to preserve the existing formats that Excel has put up there and also add my own format to it. Currently when I use the Clipboard class in .NET (taking the DataObject and calling SetData inside it), all the other formats are replaced by new ones. I then tried to create a new DataObject, copy the existing format data to this data object and then set this data object in the Clipboard. This works fine but it takes time to copy the data. // Copying existing data in clipboard to our new DataObject IDataObject existingDataObject = Clipboard.GetDataObject(); DataObject dataObject = new DataObject(); string[] existingFormats = existingDataObject.GetFormats(); foreach (string existingFormat in existingFormats) dataObject.SetData(existingFormat, existingDataObject.GetData(existingFormat)); I am looking for a solution to just access the existing DataObject and quietly add my own data to it without affecting other formats. Excel Clipboard Formats - (Ignore the Native Format)

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  • Help Repainting a Line

    - by serhio
    I am doing a custom control (inherited from VisualBasic.PowerPacks.LineShape), that should be painted like as standard one, but also having a Icon displayed near it. So, I just overrided OnPaint like this: protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { e.Graphics.DrawIcon(myIcon, StartPoint.X, StartPoint.Y); base.OnPaint(e); } Now, everything is OK, but when my control moves, the icon still remains drawn on the ancient place. Is there a way to paint it properly? The sample code for tests using Microsoft.VisualBasic.PowerPacks; using System.Windows.Forms; using System.Drawing; namespace LineShapeTest { /// /// Test Form /// public class Form1 : Form { IconLineShape myLine = new IconLineShape(); ShapeContainer shapeContainer1 = new ShapeContainer(); Panel panel1 = new Panel(); public Form1() { this.panel1.Dock = DockStyle.Fill; // load your back image here this.panel1.BackgroundImage = global::WindowsApplication22.Properties.Resources._13820t; this.panel1.Controls.Add(shapeContainer1); this.myLine.StartPoint = new Point(20, 30); this.myLine.EndPoint = new Point(80, 120); this.myLine.Parent = this.shapeContainer1; MouseEventHandler panelMouseMove = new MouseEventHandler(this.panel1_MouseMove); this.panel1.MouseMove += panelMouseMove; this.shapeContainer1.MouseMove += panelMouseMove; this.Controls.Add(panel1); } private void panel1_MouseMove(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { myLine.StartPoint = e.Location; } } } /// /// Test LineShape /// public class IconLineShape : LineShape { Icon myIcon = SystemIcons.Exclamation; protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { e.Graphics.DrawIcon(myIcon, StartPoint.X, StartPoint.Y); base.OnPaint(e); } } } Nota Bene, for the lineShape: Parent = ShapeContainer Parent.Parent = Panel Update 1 TRACES In this variant of OnPaint, we have traces: protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { Graphics g = Parent.Parent.CreateGraphics(); g.DrawIcon(myIcon, StartPoint.X, StartPoint.Y); base.OnPaint(e); } Update 2 BLINKS In this variant of OnPaint, we have a blinking image: protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { Parent.Parent.Invalidate(this.Region, true); Graphics g = Parent.Parent.CreateGraphics(); g.DrawIcon(myIcon, StartPoint.X, StartPoint.Y); base.OnPaint(e); } Update 3: External Invalidation This variant works well, but... from exterior of IconLineShape class: private void panel1_MouseMove(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { Region r = myLine.Region; myLine.StartPoint = e.Location; panel1.Invalidate(r); } } /// /// Test LineShape /// public class IconLineShape : LineShape { Icon myIcon = SystemIcons.Exclamation; Graphics parentGraphics; protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { parentGraphics.DrawIcon(myIcon, StartPoint.X, StartPoint.Y); base.OnPaint(e); } protected override void OnParentChanged(System.EventArgs e) { // Parent is a ShapeContainer // Parent.Parent is a Panel parentGraphics = Parent.Parent.CreateGraphics(); base.OnParentChanged(e); } } Even this resolves the problem of the test example, I need this control to be done inside the control, because I can't force the external "clients" of this control do not forget to save the old region and invalidate the parent each time changing a location...

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  • How can I SETF an element in a tree by an accessor?

    - by Willi Ballenthin
    We've been using Lisp in my AI course. The assignments I've received have involved searching and generating tree-like structures. For each assignment, I've ended up writing something like: (defun initial-state () (list 0 ; score nil ; children 0 ; value 0)) ; something else and building my functions around these "states", which are really just nested lists with some loosely defined structure. To make the structure more rigid, I've tried to write accessors, such as: (defun state-score ( state ) (nth 2 state)) This works for reading the value (which should be all I need to do in a nicely functional world. However, as time crunches, and I start to madly hack, sometimes I want a mutable structure). I don't seem to be able to SETF the returned ...thing (place? value? pointer?). I get an error with something like: (setf (state-score *state*) 10) Sometimes I seem to have a little more luck writing the accessor/mutator as a macro: (defmacro state-score ( state ) `(nth 2 ,state)) However I don't know why this should be a macro, so I certainly shouldn't write it as a macro (except that sometimes it works. Programming by coincidence is bad). What is an appropriate strategy to build up such structures? More importantly, where can I learn about whats going on here (what operations affect the memory in what way)?

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  • Vertex Buffers in opengl

    - by JB
    I'm making a small 3d graphics game/demo for personal learning. I know d3d9 and quite a bit about d3d11 but little about opengl at the moment so I'm intending to abstract out the actual rendering of the graphics so that my scene graph and everything "above" it needs to know little about how to actually draw the graphics. I intend to make it work with d3d9 then add d3d11 support and finally opengl support. Just as a learning exercise to learn about 3d graphics and abstraction. I don't know much about opengl at this point though, and don't want my abstract interface to expose anything that isn't simple to implement in opengl. Specifically I'm looking at vertex buffers. In d3d they are essentially an array of structures, but looking at the opengl interface the equivalent seems to be vertex arrays. However these seem to be organised rather differently where you need a separate array for vertices, one for normals, one for texture coordinates etc and set the with glVertexPointer, glTexCoordPointer etc. I was hoping to be able to implement a VertexBuffer interface much like the the directx one but it looks like in d3d you have an array of structures and in opengl you need a separate array for each element which makes finding a common abstraction quite hard to make efficient. Is there any way to use opengl in a similar way to directx? Or any suggestions on how to come up with a higher level abstraction that will work efficiently with both systems?

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  • Using OpenGL vertex buffers in C++.

    - by Ren
    I've loaded a Wavefront .obj file and drawn it in immediate mode, and it works fine. I'm now trying to draw the same model with a vertex buffer, but I have a question. My model data is organized in the following structures: struct Vert { double x; double y; double z; }; struct Norm { double x; double y; double z; }; struct Texcoord { double u; double v; double w; }; struct Face { unsigned int v[3]; unsigned int n[3]; unsigned int t[3]; }; struct Model { unsigned int vertNumber; unsigned int normNumber; unsigned int texcoordNumber; unsigned int faceNumber; Vert * vertArray; Norm * normArray; Texcoord * texcoordArray; Face * faceArray; }; As it is now, I don't think there is any redundant data, since multiple face structures can point to the same vertex, normal, or texture coordinate. When I make vbo's for the vertex positions, normals, and texture coordinates, and assign data to them with glBufferData, do I have to have make arrays with redundant data so that they will all have the same number of elements in the same order? I'd like to know if there is a simpler way to fill the buffers with the way I already have the model's data organized.

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  • va_arg with pointers

    - by Yktula
    I want to initialize a linked list with pointer arguments like so: /* * Initialize a linked list using variadic arguments * Returns the number of structures initialized */ int init_structures(struct structure *first, ...) { struct structure *s; unsigned int count = 0; va_list va; va_start(va, first); for (s = first; s != NULL; s = va_arg(va, (struct structure *))) { if ((s = malloc(sizeof(struct structure))) == NULL) { perror("malloc"); exit(EXIT_FAILURE); } count++; } va_end(va); return count; } The problem is that clang errors type name requires a specifier or qualifier at va_arg(va, (struct structure *)), and says that the type specifier defaults to int. It also notes instantiated form at (struct structure *) and struct structure *. This, what seems to be getting assigned to s is int (struct structure *). It compiles fine when parentheses are removed from (struct structure *), but the structures that are supposed to be initialized are inaccessible. Why is int assumed when parentheses are around the type argument passed to va_arg? How can I fix this?

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  • Is it a good idea to use MySQL and Neo4j together?

    - by Sanoj
    I will make an application with a lot of similar items (millions), and I would like to store them in a MySQL database, because I would like to do a lot of statistics and search on specific values for specific columns. But at the same time, I will store relations between all the items, that are related in many connected binary-tree-like structures (transitive closure), and relation databases are not good at that kind of structures, so I would like to store all relations in Neo4j which have good performance for this kind of data. My plan is to have all data except the relations in the MySQL database and all relations with item_id stored in the Neo4j database. When I want to lookup a tree, I first search the Neo4j for all the item_id:s in the tree, then I search the MySQL-database for all the specified items in a query that would look like: SELECT * FROM items WHERE item_id = 45 OR item_id = 345435 OR item_id = 343 OR item_id = 78 OR item_id = 4522 OR item_id = 676 OR item_id = 443 OR item_id = 4255 OR item_id = 4345 Is this a good idea, or am I very wrong? I haven't used graph-databases before. Are there any better approaches to my problem? How would the MySQL-query perform in this case?

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  • Debugging instance of another thread altering my data

    - by Mick
    I have a huge global array of structures. Some regions of the array are tied to individual threads and those threads can modify their regions of the array without having to use critical sections. But there is one special region of the array which all threads may have access to. The code that accesses these parts of the array needs to carefully use critical sections (each array element has its own critical section) to prevent any possibility of two threads writing to the structure simultaneously. Now I have a mysterious bug I am trying to chase, it is occurring unpredictably and very infrequently. It seems that one of the structures is being filled with some incorrect number. One obvious explanation is that another thread has accidentally been allowed to set this number when it should be excluded from doing so. Unfortunately it seems close to impossible to track this bug. The array element in which the bad data appears is different each time. What I would love to be able to do is set some kind of trap for the bug as follows: I would enter a critical section for array element N, then I know that no other thread should be able to touch the data, then (until I exit the critical section) set some kind of flag to a debugging tool saying "if any other thread attempts to change the data here please break and show me the offending patch of source code"... but I suspect no such tool exists... or does it? Or is there some completely different debugging methodology that I should be employing.

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  • How to write a "thread safe" function in C ?

    - by Andrei Ciobanu
    Hello I am writing some data structures in C, and I've realized that their associated functions aren't thread safe. The i am writing code uses only standard C, and I want to achieve some sort of 'synchronization'. I was thinking to do something like this: enum sync_e { TRUE, FALSE }; typedef enum sync_e sync; struct list_s { //Other stuff struct list_node_s *head; struct list_node_s *tail; enum sync_e locked; }; typedef struct list_s list; , to include a "boolean" field in the list structure that indicates the structures state: locked, unlocked. For example an insertion function will be rewritten this way: int list_insert_next(list* l, list_node *e, int x){ while(l->locked == TRUE){ /* Wait */ } l->locked = TRUE; /* Insert element */ /* -------------- */ l->locked = FALSE; return (0); } While operating on the list the 'locked' field will be set to TRUE, not allowing any other alterations. After operation completes the 'locked' field will be again set to 'TRUE'. Is this approach good ? Do you know other approaches (using only standard C).

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  • Using JSON.NET for dynamic JSON parsing

    - by Rick Strahl
    With the release of ASP.NET Web API as part of .NET 4.5 and MVC 4.0, JSON.NET has effectively pushed out the .NET native serializers to become the default serializer for Web API. JSON.NET is vastly more flexible than the built in DataContractJsonSerializer or the older JavaScript serializer. The DataContractSerializer in particular has been very problematic in the past because it can't deal with untyped objects for serialization - like values of type object, or anonymous types which are quite common these days. The JavaScript Serializer that came before it actually does support non-typed objects for serialization but it can't do anything with untyped data coming in from JavaScript and it's overall model of extensibility was pretty limited (JavaScript Serializer is what MVC uses for JSON responses). JSON.NET provides a robust JSON serializer that has both high level and low level components, supports binary JSON, JSON contracts, Xml to JSON conversion, LINQ to JSON and many, many more features than either of the built in serializers. ASP.NET Web API now uses JSON.NET as its default serializer and is now pulled in as a NuGet dependency into Web API projects, which is great. Dynamic JSON Parsing One of the features that I think is getting ever more important is the ability to serialize and deserialize arbitrary JSON content dynamically - that is without mapping the JSON captured directly into a .NET type as DataContractSerializer or the JavaScript Serializers do. Sometimes it isn't possible to map types due to the differences in languages (think collections, dictionaries etc), and other times you simply don't have the structures in place or don't want to create them to actually import the data. If this topic sounds familiar - you're right! I wrote about dynamic JSON parsing a few months back before JSON.NET was added to Web API and when Web API and the System.Net HttpClient libraries included the System.Json classes like JsonObject and JsonArray. With the inclusion of JSON.NET in Web API these classes are now obsolete and didn't ship with Web API or the client libraries. I re-linked my original post to this one. In this post I'll discus JToken, JObject and JArray which are the dynamic JSON objects that make it very easy to create and retrieve JSON content on the fly without underlying types. Why Dynamic JSON? So, why Dynamic JSON parsing rather than strongly typed parsing? Since applications are interacting more and more with third party services it becomes ever more important to have easy access to those services with easy JSON parsing. Sometimes it just makes lot of sense to pull just a small amount of data out of large JSON document received from a service, because the third party service isn't directly related to your application's logic most of the time - and it makes little sense to map the entire service structure in your application. For example, recently I worked with the Google Maps Places API to return information about businesses close to me (or rather the app's) location. The Google API returns a ton of information that my application had no interest in - all I needed was few values out of the data. Dynamic JSON parsing makes it possible to map this data, without having to map the entire API to a C# data structure. Instead I could pull out the three or four values I needed from the API and directly store it on my business entities that needed to receive the data - no need to map the entire Maps API structure. Getting JSON.NET The easiest way to use JSON.NET is to grab it via NuGet and add it as a reference to your project. You can add it to your project with: PM> Install-Package Newtonsoft.Json From the Package Manager Console or by using Manage NuGet Packages in your project References. As mentioned if you're using ASP.NET Web API or MVC 4 JSON.NET will be automatically added to your project. Alternately you can also go to the CodePlex site and download the latest version including source code: http://json.codeplex.com/ Creating JSON on the fly with JObject and JArray Let's start with creating some JSON on the fly. It's super easy to create a dynamic object structure with any of the JToken derived JSON.NET objects. The most common JToken derived classes you are likely to use are JObject and JArray. JToken implements IDynamicMetaProvider and so uses the dynamic  keyword extensively to make it intuitive to create object structures and turn them into JSON via dynamic object syntax. Here's an example of creating a music album structure with child songs using JObject for the base object and songs and JArray for the actual collection of songs:[TestMethod] public void JObjectOutputTest() { // strong typed instance var jsonObject = new JObject(); // you can explicitly add values here using class interface jsonObject.Add("Entered", DateTime.Now); // or cast to dynamic to dynamically add/read properties dynamic album = jsonObject; album.AlbumName = "Dirty Deeds Done Dirt Cheap"; album.Artist = "AC/DC"; album.YearReleased = 1976; album.Songs = new JArray() as dynamic; dynamic song = new JObject(); song.SongName = "Dirty Deeds Done Dirt Cheap"; song.SongLength = "4:11"; album.Songs.Add(song); song = new JObject(); song.SongName = "Love at First Feel"; song.SongLength = "3:10"; album.Songs.Add(song); Console.WriteLine(album.ToString()); } This produces a complete JSON structure: { "Entered": "2012-08-18T13:26:37.7137482-10:00", "AlbumName": "Dirty Deeds Done Dirt Cheap", "Artist": "AC/DC", "YearReleased": 1976, "Songs": [ { "SongName": "Dirty Deeds Done Dirt Cheap", "SongLength": "4:11" }, { "SongName": "Love at First Feel", "SongLength": "3:10" } ] } Notice that JSON.NET does a nice job formatting the JSON, so it's easy to read and paste into blog posts :-). JSON.NET includes a bunch of configuration options that control how JSON is generated. Typically the defaults are just fine, but you can override with the JsonSettings object for most operations. The important thing about this code is that there's no explicit type used for holding the values to serialize to JSON. Rather the JSON.NET objects are the containers that receive the data as I build up my JSON structure dynamically, simply by adding properties. This means this code can be entirely driven at runtime without compile time restraints of structure for the JSON output. Here I use JObject to create a album 'object' and immediately cast it to dynamic. JObject() is kind of similar in behavior to ExpandoObject in that it allows you to add properties by simply assigning to them. Internally, JObject values are stored in pseudo collections of key value pairs that are exposed as properties through the IDynamicMetaObject interface exposed in JSON.NET's JToken base class. For objects the syntax is very clean - you add simple typed values as properties. For objects and arrays you have to explicitly create new JObject or JArray, cast them to dynamic and then add properties and items to them. Always remember though these values are dynamic - which means no Intellisense and no compiler type checking. It's up to you to ensure that the names and values you create are accessed consistently and without typos in your code. Note that you can also access the JObject instance directly (not as dynamic) and get access to the underlying JObject type. This means you can assign properties by string, which can be useful for fully data driven JSON generation from other structures. Below you can see both styles of access next to each other:// strong type instance var jsonObject = new JObject(); // you can explicitly add values here jsonObject.Add("Entered", DateTime.Now); // expando style instance you can just 'use' properties dynamic album = jsonObject; album.AlbumName = "Dirty Deeds Done Dirt Cheap"; JContainer (the base class for JObject and JArray) is a collection so you can also iterate over the properties at runtime easily:foreach (var item in jsonObject) { Console.WriteLine(item.Key + " " + item.Value.ToString()); } The functionality of the JSON objects are very similar to .NET's ExpandObject and if you used it before, you're already familiar with how the dynamic interfaces to the JSON objects works. Importing JSON with JObject.Parse() and JArray.Parse() The JValue structure supports importing JSON via the Parse() and Load() methods which can read JSON data from a string or various streams respectively. Essentially JValue includes the core JSON parsing to turn a JSON string into a collection of JsonValue objects that can be then referenced using familiar dynamic object syntax. Here's a simple example:public void JValueParsingTest() { var jsonString = @"{""Name"":""Rick"",""Company"":""West Wind"", ""Entered"":""2012-03-16T00:03:33.245-10:00""}"; dynamic json = JValue.Parse(jsonString); // values require casting string name = json.Name; string company = json.Company; DateTime entered = json.Entered; Assert.AreEqual(name, "Rick"); Assert.AreEqual(company, "West Wind"); } The JSON string represents an object with three properties which is parsed into a JObject class and cast to dynamic. Once cast to dynamic I can then go ahead and access the object using familiar object syntax. Note that the actual values - json.Name, json.Company, json.Entered - are actually of type JToken and I have to cast them to their appropriate types first before I can do type comparisons as in the Asserts at the end of the test method. This is required because of the way that dynamic types work which can't determine the type based on the method signature of the Assert.AreEqual(object,object) method. I have to either assign the dynamic value to a variable as I did above, or explicitly cast ( (string) json.Name) in the actual method call. The JSON structure can be much more complex than this simple example. Here's another example of an array of albums serialized to JSON and then parsed through with JsonValue():[TestMethod] public void JsonArrayParsingTest() { var jsonString = @"[ { ""Id"": ""b3ec4e5c"", ""AlbumName"": ""Dirty Deeds Done Dirt Cheap"", ""Artist"": ""AC/DC"", ""YearReleased"": 1976, ""Entered"": ""2012-03-16T00:13:12.2810521-10:00"", ""AlbumImageUrl"": ""http://ecx.images-amazon.com/images/I/61kTaH-uZBL._AA115_.jpg"", ""AmazonUrl"": ""http://www.amazon.com/gp/product/…ASIN=B00008BXJ4"", ""Songs"": [ { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Dirty Deeds Done Dirt Cheap"", ""SongLength"": ""4:11"" }, { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Love at First Feel"", ""SongLength"": ""3:10"" }, { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Big Balls"", ""SongLength"": ""2:38"" } ] }, { ""Id"": ""7b919432"", ""AlbumName"": ""End of the Silence"", ""Artist"": ""Henry Rollins Band"", ""YearReleased"": 1992, ""Entered"": ""2012-03-16T00:13:12.2800521-10:00"", ""AlbumImageUrl"": ""http://ecx.images-amazon.com/images/I/51FO3rb1tuL._SL160_AA160_.jpg"", ""AmazonUrl"": ""http://www.amazon.com/End-Silence-Rollins-Band/dp/B0000040OX/ref=sr_1_5?ie=UTF8&qid=1302232195&sr=8-5"", ""Songs"": [ { ""AlbumId"": ""7b919432"", ""SongName"": ""Low Self Opinion"", ""SongLength"": ""5:24"" }, { ""AlbumId"": ""7b919432"", ""SongName"": ""Grip"", ""SongLength"": ""4:51"" } ] } ]"; JArray jsonVal = JArray.Parse(jsonString) as JArray; dynamic albums = jsonVal; foreach (dynamic album in albums) { Console.WriteLine(album.AlbumName + " (" + album.YearReleased.ToString() + ")"); foreach (dynamic song in album.Songs) { Console.WriteLine("\t" + song.SongName); } } Console.WriteLine(albums[0].AlbumName); Console.WriteLine(albums[0].Songs[1].SongName); } JObject and JArray in ASP.NET Web API Of course these types also work in ASP.NET Web API controller methods. If you want you can accept parameters using these object or return them back to the server. The following contrived example receives dynamic JSON input, and then creates a new dynamic JSON object and returns it based on data from the first:[HttpPost] public JObject PostAlbumJObject(JObject jAlbum) { // dynamic input from inbound JSON dynamic album = jAlbum; // create a new JSON object to write out dynamic newAlbum = new JObject(); // Create properties on the new instance // with values from the first newAlbum.AlbumName = album.AlbumName + " New"; newAlbum.NewProperty = "something new"; newAlbum.Songs = new JArray(); foreach (dynamic song in album.Songs) { song.SongName = song.SongName + " New"; newAlbum.Songs.Add(song); } return newAlbum; } The raw POST request to the server looks something like this: POST http://localhost/aspnetwebapi/samples/PostAlbumJObject HTTP/1.1User-Agent: FiddlerContent-type: application/jsonHost: localhostContent-Length: 88 {AlbumName: "Dirty Deeds",Songs:[ { SongName: "Problem Child"},{ SongName: "Squealer"}]} and the output that comes back looks like this: {  "AlbumName": "Dirty Deeds New",  "NewProperty": "something new",  "Songs": [    {      "SongName": "Problem Child New"    },    {      "SongName": "Squealer New"    }  ]} The original values are echoed back with something extra appended to demonstrate that we're working with a new object. When you receive or return a JObject, JValue, JToken or JArray instance in a Web API method, Web API ignores normal content negotiation and assumes your content is going to be received and returned as JSON, so effectively the parameter and result type explicitly determines the input and output format which is nice. Dynamic to Strong Type Mapping You can also map JObject and JArray instances to a strongly typed object, so you can mix dynamic and static typing in the same piece of code. Using the 2 Album jsonString shown earlier, the code below takes an array of albums and picks out only a single album and casts that album to a static Album instance.[TestMethod] public void JsonParseToStrongTypeTest() { JArray albums = JArray.Parse(jsonString) as JArray; // pick out one album JObject jalbum = albums[0] as JObject; // Copy to a static Album instance Album album = jalbum.ToObject<Album>(); Assert.IsNotNull(album); Assert.AreEqual(album.AlbumName,jalbum.Value<string>("AlbumName")); Assert.IsTrue(album.Songs.Count > 0); } This is pretty damn useful for the scenario I mentioned earlier - you can read a large chunk of JSON and dynamically walk the property hierarchy down to the item you want to access, and then either access the specific item dynamically (as shown earlier) or map a part of the JSON to a strongly typed object. That's very powerful if you think about it - it leaves you in total control to decide what's dynamic and what's static. Strongly typed JSON Parsing With all this talk of dynamic let's not forget that JSON.NET of course also does strongly typed serialization which is drop dead easy. Here's a simple example on how to serialize and deserialize an object with JSON.NET:[TestMethod] public void StronglyTypedSerializationTest() { // Demonstrate deserialization from a raw string var album = new Album() { AlbumName = "Dirty Deeds Done Dirt Cheap", Artist = "AC/DC", Entered = DateTime.Now, YearReleased = 1976, Songs = new List<Song>() { new Song() { SongName = "Dirty Deeds Done Dirt Cheap", SongLength = "4:11" }, new Song() { SongName = "Love at First Feel", SongLength = "3:10" } } }; // serialize to string string json2 = JsonConvert.SerializeObject(album,Formatting.Indented); Console.WriteLine(json2); // make sure we can serialize back var album2 = JsonConvert.DeserializeObject<Album>(json2); Assert.IsNotNull(album2); Assert.IsTrue(album2.AlbumName == "Dirty Deeds Done Dirt Cheap"); Assert.IsTrue(album2.Songs.Count == 2); } JsonConvert is a high level static class that wraps lower level functionality, but you can also use the JsonSerializer class, which allows you to serialize/parse to and from streams. It's a little more work, but gives you a bit more control. The functionality available is easy to discover with Intellisense, and that's good because there's not a lot in the way of documentation that's actually useful. Summary JSON.NET is a pretty complete JSON implementation with lots of different choices for JSON parsing from dynamic parsing to static serialization, to complex querying of JSON objects using LINQ. It's good to see this open source library getting integrated into .NET, and pushing out the old and tired stock .NET parsers so that we finally have a bit more flexibility - and extensibility - in our JSON parsing. Good to go! Resources Sample Test Project http://json.codeplex.com/© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET  Web Api  AJAX   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • CodePlex Daily Summary for Thursday, March 18, 2010

    CodePlex Daily Summary for Thursday, March 18, 2010New ProjectsBordecal tools for FxCop: Bordecal tools for FxCop provides an extended framework for FxCop rule development. It allows rule developers to avoid using embedded XML resource...DotNetNuke® Skin City: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by allsnnskins. We integrate orange color and black colour in this ...DotNetNuke® Skin Dawn: A DotNetNuke Design Challenge skin package submitted to the "Out of the box" category by allsnnskins. This design reflects the theme of daylight. U...DotNetNuke® Skin Dream: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by WhNuke. Uses the DNNJDMenu skin object.DotNetNuke® Skin Expression: A DotNetNuke Design Challenge skin package submitted to the "Out of the box" category by Salar Golestanian of SalarO. This is a pure CSS skin with ...DotNetNuke® Skin ModernBiz: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by allsnnskins. This simple and unaffected company skin uses...DotNetNuke® Skin Profound: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by WhNuke Technology. This skin is simple and clean and the ...DotNetNuke® Skin Technology: A DotNetNuke Design Challenge skin package submitted to the "Modern Standards" category by allsnnskins. It's compatible with common browsers such ...DotNetNuke® Skin Unravel: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by Salar Golestanian of SalarO. This is a pure CSS skin wit...E! - ECMAScript Runtime Environment: E! (pronounced E-Bang) is a lightweight runtime environment for editing basic ECMAScript scripts with access to .NET Framework class libraries.Easy ArcGIS Library: Easy ArcGIS Library is a set of C# .net classes that wrap the common functionality of ArcObjects, that help ArcGIS developers do a lot of common fu...File Categorizer: The File Categorizer will help people tag the files on their system for easy searching. Instead of keyword searches, you can find files based on v...GMFS Cosmos: This is a file system for Cosmos a OS that was built with C# and we will be implementing this for windows and linuxIFilter Core Implementation (interface and structures): IFilter C# implementation for you to embed when writing Windows Search capabilities into your application.Image Wall Control for Silverlight: A control for Silverlight that emulates the wall of images in the Zune. imenik_za _dev4fun: imenik is a very simple program and easy to use where you can save and organise your contacts.LegoPhysX: LegoPhysX is an atomic based physics enginePersonal Accounting: Personal system for managing financial accounts, which supports multiple accounts in different currencies. It has movement imputation and basic que...Pipes & Filters Engine: The Pipes & Filters Engine allows you to process a sequence of separate operations (filters) asynchronously in a multi-threaded manner. Filters wil...Prerequisites Checker: Check preqrequisites for software. Example: Software S1 is delivered. S1 has prerequisites PR1, PR2... PRN You may load the config file for S...Puzzle Lib: A library for creating grid-and-tile puzzles. Includes two separate UIs for the Tetriminoes puzzle as examples.QuotesPlugin for Windows Live Writer: The QuotesPlugin for Windows Live Writer lists quotes from web sites such as quotes4all.net. It's very easy for you to select your favourite ones a...RobiJ2se: Robi j2se Learning!SkinEngine: This is a Skin Framework for C# Winform, It use easy.and Create Skin GreatSQL Azure .NET Connection: This is a demo application that shows how to connect with SQL AzureSupermarket Soft: WPF Application that helps you manage your supermarket shoppings.Tally Marks for Windows Phone 7 Series: Tally Marks is a counting application. It can count almost anything you'd like to count, and it does it with tally marks! Count the number of peo...TwitCast: TwitCast is a simple notifier for Twitter using the [url:http://linqtotwitter.codeplex.com/] LINQ 2 Twitter library.WodnySwiat: Projekt grupowy wodny światWSS Task Manager Activity: A custom task creation activity that can be used in a sequential or state machine workflow. The activity was specifically developed to handle task ...New ReleasesAddress Book: Address Book: Address BookAutoAudit: AutoAudit 1.10c: Veresion 1.10 includes most of the bug fix requests. adds createdby and modifiedby columns to the audited base tables. If the user name is set by...blog for umbraco 4: Blog 4 Umbraco 2.0.26: Fixes: -Regex bug in base -Directory urls and rss link bug -Open reader bug -Rss bugDotNetNuke® Skin City: City Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by allsnnskins. We integrate orange color and black colour in this ...DotNetNuke® Skin Dawn: Dawn Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Out of the box" category by allsnnskins. This design reflects the theme of daylight. U...DotNetNuke® Skin Dream: Dream Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by WhNuke. Uses the DNNJDMenu skin object.DotNetNuke® Skin Expression: Expression Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Out of the box" category by Salar Golestanian of SalarO. This is a pure CSS skin with ...DotNetNuke® Skin ModernBiz: ModernBiz Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by allsnnskins. This simple and unaffected company skin uses...DotNetNuke® Skin Profound: Profound Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by WhNuke Technology. This skin is simple and clean and the ...DotNetNuke® Skin Technology: Technology Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Modern Standards" category by allsnnskins. It's compatible with common browsers such a...DotNetNuke® Skin Unravel: Unravel Package 1.0.0: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by Salar Golestanian of SalarO. This is a pure CSS skin with...E! - ECMAScript Runtime Environment: E! beta 1: This is really meant as a learning project for playing with dynamically compiled code, so you'd be better off getting the source code.Easy ArcGIS Library: EAGL Binaries: Easy ArcGIS Library Last Build (Version 1.1.2.4139)Easy ArcGIS Library: EAGL Binaries And Documentation: EAGL Latest Build With DocumentationEasy ArcGIS Library: EAGL Documentation: EAGL 1.1.2.4139 DocumentationEnterprise Library Extensions: Release 1.1: This is a service release for version 1.0 The installation process now works as intended. The assemblies are now visible in the Visual Studio As...Family Tree Analyzer: Version 1.2.1.0: Version 1.2.1.0 Fixed GB radio button not working renamed UK Added fixes for UK regions/shires/counties where country is missing Add country reco...Family Tree Analyzer: Version 1.3.0.0: Version 1.3.0.0 Added IGI Search results viewer Tweaked filenames of IGI search so that results window has more informative displayFile Archive: File Archive: If your computer is only word processing machine or document merge machine, this program is really fit for you. It's so...o useful! This program ar...GameStore League Manager: League Manager 1.0.4: Fixes bug 7434. 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  • Oracle Data Integrator 11.1.1.5 Complex Files as Sources and Targets

    - by Alex Kotopoulis
    Overview ODI 11.1.1.5 adds the new Complex File technology for use with file sources and targets. The goal is to read or write file structures that are too complex to be parsed using the existing ODI File technology. This includes: Different record types in one list that use different parsing rules Hierarchical lists, for example customers with nested orders Parsing instructions in the file data, such as delimiter types, field lengths, type identifiers Complex headers such as multiple header lines or parseable information in header Skipping of lines  Conditional or choice fields Similar to the ODI File and XML File technologies, the complex file parsing is done through a JDBC driver that exposes the flat file as relational table structures. Complex files are mapped to one or more table structures, as opposed to the (simple) file technology, which always has a one-to-one relationship between file and table. The resulting set of tables follows the same concept as the ODI XML driver, table rows have additional PK-FK relationships to express hierarchy as well as order values to maintain the file order in the resulting table.   The parsing instruction format used for complex files is the nXSD (native XSD) format that is already in use with Oracle BPEL. This format extends the XML Schema standard by adding additional parsing instructions to each element. Using nXSD parsing technology, the native file is converted into an internal XML format. It is important to understand that the XML is streamed to improve performance; there is no size limitation of the native file based on memory size, the XML data is never fully materialized.  The internal XML is then converted to relational schema using the same mapping rules as the ODI XML driver. How to Create an nXSD file Complex file models depend on the nXSD schema for the given file. This nXSD file has to be created using a text editor or the Native Format Builder Wizard that is part of Oracle BPEL. BPEL is included in the ODI Suite, but not in standalone ODI Enterprise Edition. The nXSD format extends the standard XSD format through nxsd attributes. NXSD is a valid XML Schema, since the XSD standard allows extra attributes with their own namespaces. The following is a sample NXSD schema: <?xml version="1.0"?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:nxsd="http://xmlns.oracle.com/pcbpel/nxsd" elementFormDefault="qualified" xmlns:tns="http://xmlns.oracle.com/pcbpel/demoSchema/csv" targetNamespace="http://xmlns.oracle.com/pcbpel/demoSchema/csv" attributeFormDefault="unqualified" nxsd:encoding="US-ASCII" nxsd:stream="chars" nxsd:version="NXSD"> <xsd:element name="Root">         <xsd:complexType><xsd:sequence>       <xsd:element name="Header">                 <xsd:complexType><xsd:sequence>                         <xsd:element name="Branch" type="xsd:string" nxsd:style="terminated" nxsd:terminatedBy=","/>                         <xsd:element name="ListDate" type="xsd:string" nxsd:style="terminated" nxsd:terminatedBy="${eol}"/>                         </xsd:sequence></xsd:complexType>                         </xsd:element>                 </xsd:sequence></xsd:complexType>         <xsd:element name="Customer" maxOccurs="unbounded">                 <xsd:complexType><xsd:sequence>                 <xsd:element name="Name" type="xsd:string" nxsd:style="terminated" nxsd:terminatedBy=","/>                         <xsd:element name="Street" type="xsd:string" nxsd:style="terminated" nxsd:terminatedBy="," />                         <xsd:element name="City" type="xsd:string" nxsd:style="terminated" nxsd:terminatedBy="${eol}" />                         </xsd:sequence></xsd:complexType>                         </xsd:element>                 </xsd:sequence></xsd:complexType> </xsd:element> </xsd:schema> The nXSD schema annotates elements to describe their position and delimiters within the flat text file. The schema above uses almost exclusively the nxsd:terminatedBy instruction to look for the next terminator chars. There are various constructs in nXSD to parse fixed length fields, look ahead in the document for string occurences, perform conditional logic, use variables to remember state, and many more. nXSD files can either be written manually using an XML Schema Editor or created using the Native Format Builder Wizard. Both Native Format Builder Wizard as well as the nXSD language are described in the Application Server Adapter Users Guide. The way to start the Native Format Builder in BPEL is to create a new File Adapter; in step 8 of the Adapter Configuration Wizard a new Schema for Native Format can be created:   The Native Format Builder guides through a number of steps to generate the nXSD based on a sample native file. If the format is complex, it is often a good idea to “approximate” it with a similar simple format and then add the complex components manually.  The resulting *.xsd file can be copied and used as the format for ODI, other BPEL constructs such as the file adapter definition are not relevant for ODI. Using this technique it is also possible to parse the same file format in SOA Suite and ODI, for example using SOA for small real-time messages, and ODI for large batches. This nXSD schema in this example describes a file with a header row containing data and 3 string fields per row delimited by commas, for example: Redwood City Downtown Branch, 06/01/2011 Ebeneezer Scrooge, Sandy Lane, Atherton Tiny Tim, Winton Terrace, Menlo Park The ODI Complex File JDBC driver exposes the file structure through a set of relational tables with PK-FK relationships. The tables for this example are: Table ROOT (1 row): ROOTPK Primary Key for root element SNPSFILENAME Name of the file SNPSFILEPATH Path of the file SNPSLOADDATE Date of load Table HEADER (1 row): ROOTFK Foreign Key to ROOT record ROWORDER Order of row in native document BRANCH Data BRANCHORDER Order of Branch within row LISTDATE Data LISTDATEORDER Order of ListDate within row Table ADDRESS (2 rows): ROOTFK Foreign Key to ROOT record ROWORDER Order of row in native document NAME Data NAMEORDER Oder of Name within row STREET Data STREETORDER Order of Street within row CITY Data CITYORDER Order of City within row Every table has PK and/or FK fields to reflect the document hierarchy through relationships. In this example this is trivial since the HEADER and all CUSTOMER records point back to the PK of ROOT. Deeper nested documents require this to identify parent elements. All tables also have a ROWORDER field to define the order of rows, as well as order fields for each column, in case the order of columns varies in the original document and needs to be maintained. If order is not relevant, these fields can be ignored. How to Create an Complex File Data Server in ODI After creating the nXSD file and a test data file, and storing it on the local file system accessible to ODI, you can go to the ODI Topology Navigator to create a Data Server and Physical Schema under the Complex File technology. This technology follows the conventions of other ODI technologies and is very similar to the XML technology. The parsing settings such as the source native file, the nXSD schema file, the root element, as well as the external database can be set in the JDBC URL: The use of an external database defined by dbprops is optional, but is strongly recommended for production use. Ideally, the staging database should be used for this. Also, when using a complex file exclusively for read purposes, it is recommended to use the ro=true property to ensure the file is not unnecessarily synchronized back from the database when the connection is closed. A data file is always required to be present  at the filename path during design-time. Without this file, operations like testing the connection, reading the model data, or reverse engineering the model will fail.  All properties of the Complex File JDBC Driver are documented in the Oracle Fusion Middleware Connectivity and Knowledge Modules Guide for Oracle Data Integrator in Appendix C: Oracle Data Integrator Driver for Complex Files Reference. David Allan has created a great viewlet Complex File Processing - 0 to 60 which shows the creation of a Complex File data server as well as a model based on this server. How to Create Models based on an Complex File Schema Once physical schema and logical schema have been created, the Complex File can be used to create a Model as if it were based on a database. When reverse-engineering the Model, data stores(tables) for each XSD element of complex type will be created. Use of complex files as sources is straightforward; when using them as targets it has to be made sure that all dependent tables have matching PK-FK pairs; the same applies to the XML driver as well. Debugging and Error Handling There are different ways to test an nXSD file. The Native Format Builder Wizard can be used even if the nXSD wasn’t created in it; it will show issues related to the schema and/or test data. In ODI, the nXSD  will be parsed and run against the existing test XML file when testing a connection in the Dataserver. If either the nXSD has an error or the data is non-compliant to the schema, an error will be displayed. Sample error message: Error while reading native data. [Line=1, Col=5] Not enough data available in the input, when trying to read data of length "19" for "element with name D1" from the specified position, using "style" as "fixedLength" and "length" as "". Ensure that there is enough data from the specified position in the input. Complex File FAQ Is the size of the native file limited by available memory? No, since the native data is streamed through the driver, only the available space in the staging database limits the size of the data. There are limits on individual field sizes, though; a single large object field needs to fit in memory. Should I always use the complex file driver instead of the file driver in ODI now? No, use the file technology for all simple file parsing tasks, for example any fixed-length or delimited files that just have one row format and can be mapped into a simple table. Because of its narrow assumptions the ODI file driver is easy to configure within ODI and can stream file data without writing it into a database. The complex file driver should be used whenever the use case cannot be handled through the file driver. Are we generating XML out of flat files before we write it into a database? We don’t materialize any XML as part of parsing a flat file, either in memory or on disk. The data produced by the XML parser is streamed in Java objects that just use XSD-derived nXSD schema as its type system. We use the nXSD schema because is the standard for describing complex flat file metadata in Oracle Fusion Middleware, and enables users to share schemas across products. Is the nXSD file interchangeable with SOA Suite? Yes, ODI can use the same nXSD files as SOA Suite, allowing mixed use cases with the same data format. Can I start the Native Format Builder from the ODI Studio? No, the Native Format Builder has to be started from a JDeveloper with BPEL instance. You can get BPEL as part of the SOA Suite bundle. Users without SOA Suite can manually develop nXSD files using XSD editors. When is the database data written back to the native file? Data is synchronized using the SYNCHRONIZE and CREATE FILE commands, and when the JDBC connection is closed. It is recommended to set the ro or read_only property to true when a file is exclusively used for reading so that no unnecessary write-backs occur. Is the nXSD metadata part of the ODI Master or Work Repository? No, the data server definition in the master repository only contains the JDBC URL with file paths; the nXSD files have to be accessible on the file systems where the JDBC driver is executed during production, either by copying or by using a network file system. Where can I find sample nXSD files? The Application Server Adapter Users Guide contains nXSD samples for various different use cases.

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  • .NET Code Evolution

    - by Alois Kraus
    Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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  • RoboCopy Log File Analysis

    - by BobJim
    Is it possible to analyse the log text file outputted from RoboCopy and extract the lines which are defined as "New Dir" and "Extra Dir"? I would like the line from the log contain all the details returned regarding this "New Dir" or "Extra Dir" The reason for completing this task is to understand how two folder structures have change over time. One version has been kept internally at the parent company, the second has been used by a consultancy. For your information I am using Windows 7.

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  • Having trouble using psservice and sc.exe between Windows Server 2008 machines

    - by Teflon Mac
    I'm trying to control services on one W2k8 machine from another; no domain just a workgroup. The user account I'm logged in as is an administrator on both machines. I've tried both psservice and sc.exe. These work in a Windows Server 2003 environment but it looks like I need to an extra step or two due to the changed security model in 2008. Any ideas as to how grant permission to the Service Control Manager (psservice) or OpenService (sc)? I tried running the DOS window with "Run As Administrator" and it made no difference. With psservice I get the following D:\mydir>psservice \\REMOTESERVER -u "adminid" -p "adminpassword" start "Display Name of Service" PsService v2.22 - Service information and configuration utility Copyright (C) 2001-2008 Mark Russinovich Sysinternals - www.sysinternals.com Unable to access Service Control Manager on \\REMOTESERVER: Access is denied. In the remote server, I get the following message in the Security Log so I know I connect and login to the remote machine. I assume it then fails on a subsequent authorization step. The logoff message in the security log is just that ("An account was logged off."), so no extra info there. Special privileges assigned to new logon. Subject: Security ID: REMOTESERVER\adminid Account Name: adminid Account Domain: REMOTESERVER Logon ID: 0xxxxxxxx Privileges: SeSecurityPrivilege SeBackupPrivilege SeRestorePrivilege SeTakeOwnershipPrivilege SeDebugPrivilege SeSystemEnvironmentPrivilege SeLoadDriverPrivilege SeImpersonatePrivilege sc.exe is similar. The command syntax and error differs as below but I also see the same login message in the remote server's security log. D:\mydir>sc \\REMOTESERVER start "Registry Name of Service" [SC] StartService: OpenService FAILED 5: Access is denied.

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  • QoS for Cisco Router to Prioritize Voice and Interactive Traffic

    - by TJ Huffington
    I have a Cisco 891W NATing Voice and Data to the internet over a 10mbit/2mbit connection. Voice traffic gets degraded when I upload large files. Pings time out as well. I tried to configure a QoS policy but it's basically not doing anything. Voice traffic still degrades when upload bandwidth gets saturated. Here is my current configruation: class-map match-any QoS-Transactional match protocol ssh match protocol xwindows class-map match-any QoS-Voice match protocol rtp audio class-map match-any QoS-Bulk match protocol secure-nntp match protocol smtp match protocol tftp match protocol ftp class-map match-any QoS-Management match protocol snmp match protocol dns match protocol secure-imap class-map match-any QoS-Inter-Video match protocol rtp video class-map match-any QoS-Voice-Control match access-group name Voice-Control policy-map QoS-Priority-Output class QoS-Voice priority percent 25 set dscp ef class QoS-Inter-Video bandwidth remaining percent 10 set dscp af41 class QoS-Transactional bandwidth remaining percent 25 random-detect dscp-based set dscp af21 class QoS-Bulk bandwidth remaining percent 5 random-detect dscp-based set dscp af11 class QoS-Management bandwidth remaining percent 1 set dscp cs2 class QoS-Voice-Control priority percent 5 set dscp ef class class-default fair-queue interface FastEthernet8 bandwidth 1024 bandwidth receive 20480 ip address dhcp ip nat outside ip virtual-reassembly duplex auto speed auto auto discovery qos crypto map mymap max-reserved-bandwidth 80 service-policy output QoS-Priority-Output crypto map mymap 10 ipsec-isakmp set peer 1.2.3.4 default set transform-set ESP-3DES-SHA match address 110 qos pre-classify ! fa8 is my connection to the internet. Voice traffic goes over a VPN ("mymap") to the SIP server. That's why I specified "qos pre-classify" which I believe is the way to classify traffic over the VPN. However even when I ping a public IP while saturating upload bandwidth, the latency is exceptionally high. Is this configuration correct? Are there any suggestions that might make this work for my setup? Thanks in advance.

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