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  • Defining where on the page the flowdocument I am printing will 'start' and 'end'

    - by Sagi1981
    Dear community. I am almost done with implementing a printing functionality, but I am having trouble getting the last hurdle done with. My problem is, that I am printing some reports, consisting of a header (with information about the person the report is about), a footer (with a page number) and the content in the middle, which is a FlowDocument. Since the flowdocuments can be fairly long, It is very possible that they will span multiple pages. My approach is to make a custom FlowDocumentPaginator which derives from DocumentPaginator. In there i define my header and my footer. However, when I print my page, the flowdocument and my header and footer are on top of eachother. So my question is plain and simple - how do I define from where and to where the flowdocument part on the pages will be placed? here is the code from my custommade Paginator: public class HeaderedFlowDocumentPaginator : DocumentPaginator { private DocumentPaginator flowDocumentpaginator; public HeaderedFlowDocumentPaginator(FlowDocument document) { flowDocumentpaginator = ((IDocumentPaginatorSource) document).DocumentPaginator; } public override bool IsPageCountValid { get { return flowDocumentpaginator.IsPageCountValid; } } public override int PageCount { get { return flowDocumentpaginator.PageCount; } } public override Size PageSize { get { return flowDocumentpaginator.PageSize; } set { flowDocumentpaginator.PageSize = value; } } public override IDocumentPaginatorSource Source { get { return flowDocumentpaginator.Source; } } public override DocumentPage GetPage(int pageNumber) { DocumentPage page = flowDocumentpaginator.GetPage(pageNumber); ContainerVisual newVisual = new ContainerVisual(); newVisual.Children.Add(page.Visual); DrawingVisual header = new DrawingVisual(); using (DrawingContext dc = header.RenderOpen()) { //Header data } newVisual.Children.Add(header); DrawingVisual footer = new DrawingVisual(); using (DrawingContext dc = footer.RenderOpen()) { Typeface typeface = new Typeface("Trebuchet MS"); FormattedText text = new FormattedText("Page " + (pageNumber + 1).ToString(), CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeface, 14, Brushes.Black); dc.DrawText(text, new Point(page.Size.Width - 100, page.Size.Height-30)); } newVisual.Children.Add(footer); DocumentPage newPage = new DocumentPage(newVisual); return newPage; } } And here is the printdialogue call: private void btnPrint_Click(object sender, RoutedEventArgs e) { try { PrintDialog printDialog = new PrintDialog(); if (printDialog.ShowDialog() == true) { FlowDocument fd = new FlowDocument(); MemoryStream stream = new MemoryStream(ASCIIEncoding.Default.GetBytes(<My string of text - RTF formatted>)); TextRange tr = new TextRange(fd.ContentStart, fd.ContentEnd); tr.Load(stream, DataFormats.Rtf); stream.Close(); fd.ColumnWidth = printDialog.PrintableAreaWidth; HeaderedFlowDocumentPaginator paginator = new HeaderedFlowDocumentPaginator(fd); printDialog.PrintDocument(paginator, "myReport"); } } catch (Exception ex) { //Handle } }

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  • Bulk inserts into sqlite db on the iphone...

    - by akaii
    I'm inserting a batch of 100 records, each containing a dictonary containing arbitrarily long HTML strings, and by god, it's slow. On the iphone, the runloop is blocking for several seconds during this transaction. Is my only recourse to use another thread? I'm already using several for acquiring data from HTTP servers, and the sqlite documentation explicitly discourages threading with the database, even though it's supposed to be thread-safe... Is there something I'm doing extremely wrong that if fixed, would drastically reduce the time it takes to complete the whole operation? NSString* statement; statement = @"BEGIN EXCLUSIVE TRANSACTION"; sqlite3_stmt *beginStatement; if (sqlite3_prepare_v2(database, [statement UTF8String], -1, &beginStatement, NULL) != SQLITE_OK) { printf("db error: %s\n", sqlite3_errmsg(database)); return; } if (sqlite3_step(beginStatement) != SQLITE_DONE) { sqlite3_finalize(beginStatement); printf("db error: %s\n", sqlite3_errmsg(database)); return; } NSTimeInterval timestampB = [[NSDate date] timeIntervalSince1970]; statement = @"INSERT OR REPLACE INTO item (hash, tag, owner, timestamp, dictionary) VALUES (?, ?, ?, ?, ?)"; sqlite3_stmt *compiledStatement; if(sqlite3_prepare_v2(database, [statement UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK) { for(int i = 0; i < [items count]; i++){ NSMutableDictionary* item = [items objectAtIndex:i]; NSString* tag = [item objectForKey:@"id"]; NSInteger hash = [[NSString stringWithFormat:@"%@%@", tag, ownerID] hash]; NSInteger timestamp = [[item objectForKey:@"updated"] intValue]; NSData *dictionary = [NSKeyedArchiver archivedDataWithRootObject:item]; sqlite3_bind_int( compiledStatement, 1, hash); sqlite3_bind_text( compiledStatement, 2, [tag UTF8String], -1, SQLITE_TRANSIENT); sqlite3_bind_text( compiledStatement, 3, [ownerID UTF8String], -1, SQLITE_TRANSIENT); sqlite3_bind_int( compiledStatement, 4, timestamp); sqlite3_bind_blob( compiledStatement, 5, [dictionary bytes], [dictionary length], SQLITE_TRANSIENT); while(YES){ NSInteger result = sqlite3_step(compiledStatement); if(result == SQLITE_DONE){ break; } else if(result != SQLITE_BUSY){ printf("db error: %s\n", sqlite3_errmsg(database)); break; } } sqlite3_reset(compiledStatement); } timestampB = [[NSDate date] timeIntervalSince1970] - timestampB; NSLog(@"Insert Time Taken: %f",timestampB); // COMMIT statement = @"COMMIT TRANSACTION"; sqlite3_stmt *commitStatement; if (sqlite3_prepare_v2(database, [statement UTF8String], -1, &commitStatement, NULL) != SQLITE_OK) { printf("db error: %s\n", sqlite3_errmsg(database)); } if (sqlite3_step(commitStatement) != SQLITE_DONE) { printf("db error: %s\n", sqlite3_errmsg(database)); } sqlite3_finalize(beginStatement); sqlite3_finalize(compiledStatement); sqlite3_finalize(commitStatement);

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  • C#: Windows Forms: What could cause Invalidate() to not redraw?

    - by Rosarch
    I'm using Windows Forms. For a long time, pictureBox.Invalidate(); worked to make the screen be redrawn. However, it now doesn't work and I'm not sure why. this.worldBox = new System.Windows.Forms.PictureBox(); this.worldBox.BackColor = System.Drawing.SystemColors.Control; this.worldBox.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle; this.worldBox.Location = new System.Drawing.Point(170, 82); this.worldBox.Name = "worldBox"; this.worldBox.Size = new System.Drawing.Size(261, 250); this.worldBox.TabIndex = 0; this.worldBox.TabStop = false; this.worldBox.MouseMove += new System.Windows.Forms.MouseEventHandler(this.worldBox_MouseMove); this.worldBox.MouseDown += new System.Windows.Forms.MouseEventHandler(this.worldBox_MouseDown); this.worldBox.MouseUp += new System.Windows.Forms.MouseEventHandler(this.worldBox_MouseUp); Called in my code to draw the world appropriately: view.DrawWorldBox(worldBox, canvas, gameEngine.GameObjectManager.Controllers, selectedGameObjects, LevelEditorUtils.PREVIEWS); View.DrawWorldBox: public void DrawWorldBox(PictureBox worldBox, Panel canvas, ICollection<IGameObjectController> controllers, ICollection<IGameObjectController> selectedGameObjects, IDictionary<string, Image> previews) { int left = Math.Abs(worldBox.Location.X); int top = Math.Abs(worldBox.Location.Y); Rectangle screenRect = new Rectangle(left, top, canvas.Width, canvas.Height); IDictionary<float, ICollection<IGameObjectController>> layers = LevelEditorUtils.LayersOfControllers(controllers); IOrderedEnumerable<KeyValuePair<float, ICollection<IGameObjectController>>> sortedLayers = from item in layers orderby item.Key descending select item; using (Graphics g = Graphics.FromImage(worldBox.Image)) { foreach (KeyValuePair<float, ICollection<IGameObjectController>> kv in sortedLayers) { foreach (IGameObjectController controller in kv.Value) { // ... float scale = controller.View.Scale; float width = controller.View.Width; float height = controller.View.Height; Rectangle controllerRect = new Rectangle((int)controller.Model.Position.X, (int)controller.Model.Position.Y, (int)(width * scale), (int)(height * scale)); // cull objects that aren't intersecting with the canvas if (controllerRect.IntersectsWith(screenRect)) { Image img = previews[controller.Model.HumanReadableName]; g.DrawImage(img, controllerRect); } if (selectedGameObjects.Contains(controller)) { selectionRectangles.Add(controllerRect); } } } foreach (Rectangle rect in selectionRectangles) { g.DrawRectangle(drawingPen, rect); } selectionRectangles.Clear(); } worldBox.Invalidate(); } What could I be doing wrong here?

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  • Installing Enclosure with Netbeans

    - by jdknewb
    Hi all, I am having trouble installing Enclosure and getting it to work. I have followed this guide http://www.enclojure.org/gettingstarted and successfully installed Enclosure (I think). However, when I try to build the sample application (labrepl) I get a bunch of errors and a failed build. I haven't used Java in a long time and I've never used Netbeans, and the error doesn't seem very helpful with my limited knowledge of this domain. I'm using the latest Netbeans and the Enclosure URL from the guide. Since I am on Windows, I can't use git to clone the repo, so I'm not sure what to do from here. Anyway, here are the error messages. WARNING: You are running embedded Maven builds, some build may fail due to incompatibilities with latest Maven release. To set Maven instance to use for building, click here. Scanning for projects... [#process-resources] [resources:resources] Using default encoding to copy filtered resources. [#compile] [ERROR]Transitive dependency resolution for scope: compile has failed for your project. [ERROR]Error message: Missing: [ERROR]---------- [ERROR]1) org.clojure:clojure-contrib:jar:1.2.0-master-SNAPSHOT [ERROR] Try downloading the file manually from the project website. [ERROR] Then, install it using the command: [ERROR] mvn install:install-file -DgroupId=org.clojure -DartifactId=clojure-contrib -Dversion=1.2.0-master-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file [ERROR] Alternatively, if you host your own repository you can deploy the file there: [ERROR] mvn deploy:deploy-file -DgroupId=org.clojure -DartifactId=clojure-contrib -Dversion=1.2.0-master-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id] [ERROR] Path to dependency: [ERROR] 1) labrepl:labrepl:jar:0.0.1 [ERROR] 2) org.clojure:clojure-contrib:jar:1.2.0-master-SNAPSHOT [ERROR]---------- [ERROR]1 required artifact is missing. [ERROR]for artifact: [ERROR] labrepl:labrepl:jar:0.0.1 [ERROR]from the specified remote repositories: [ERROR] central (http://repo1.maven.org/maven2), [ERROR] clojars (http://clojars.org/repo/), [ERROR] incanter (http://repo.incanter.org), [ERROR] clojure-snapshots (http://build.clojure.org/snapshots), [ERROR] clojure (http://build.clojure.org/releases), [ERROR] clojure-releases (http://build.clojure.org/releases) [ERROR]Group-Id: labrepl [ERROR]Artifact-Id: labrepl [ERROR]Version: 0.0.1 [ERROR]From file: C:\Users\chloey\Documents\NetBeansProjects\RelevanceLabRepl\pom.xml ------------------------------------------------------------------------ For more information, run with the -e flag ------------------------------------------------------------------------ BUILD FAILED ------------------------------------------------------------------------ Total time: 1 second Finished at: Wed Jun 09 21:53:04 CDT 2010 Final Memory: 72M/172M ------------------------------------------------------------------------ Thanks all.

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  • PulpCore music playback - loop sound and animate volume

    - by Peter Perhác
    I have been experimenting with PulpCore, trying to create my own tower defence game (not-playable yet), and I am enjoying it very much I ran into a problem that I can't quite figure out. I extended PulpCore with the JOrbis thing to allow OGG files to be played. Works fine. However, pulpCore seems to have a problem with looping the sound WHILE animating the volume level. I tried this with wav file too, to make sure it isn't jOrbis that breaks it. The code is like this: Sound bgMusic = Sound.load("music/music.ogg"); Playback musicPlayback; ... musicVolume = new Fixed(0.75); musicPlayback = bgMusic.loop(musicVolume); //TODO figure out why it's NOT looping when volume is animated // musicVolume.animate(0, musicVolume.get(), FADE_IN_TIME); This code, for as long as the last line is commented out, plays the music.ogg again and again in an endless loop (which I can stop by calling stop on the Playback object returned from loop(). However, I would like the music to fade in smoothly, so following the advice of the PulpCore API docs, I added the last line which will create the fade-in but the music will only play once and then stop. I wonder why is that? Here is a bit of the documentation: Playback pulpcore.sound.Sound.loop(Fixed level) Loops this sound clip with the specified volume level (0.0 to 1.0). The level may have a property animation attached. Parameters: level Returns: a Playback object for this unique sound playback (one Sound can have many simultaneous Playback objects) or null if the sound could not be played. So what could be the problem? I repeat, with the last line, the sound fades in but doesn't loop, without it it loops but starts with the specified 0.75 volume level. Why can't I animate the volume of the looped music playback? What am I doing wrong? Anyone has any experience with pulpCore and has come across this problem? Anyone could please download PulpCore and try to loop music which fades-in (out)? note: I need to keep a reference to the Playback object returned so I can kill music later.

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  • Creating a ListView and setting the background color of a view in each row.

    - by Tarmon
    Hey Everyone, I am trying to implement a ListView that is composed of rows that contain a View on the left followed by a TextView to the right of that. I want to be able to change the background color of the first View based on it's position in the ListView. Below is what I have at this point but it doesn't seem to due anything. public class Routes extends ListActivity { String[] ROUTES; TextView selection; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ROUTES = getResources().getStringArray(R.array.routes); setContentView(R.layout.routes); setListAdapter(new IconicAdapter()); selection=(TextView)findViewById(R.id.selection); } public void onListItemClick(ListView parent, View v, int position, long id) { selection.setText(ROUTES[position]); } class IconicAdapter extends ArrayAdapter<String> { IconicAdapter() { super(Routes.this, R.layout.row, R.id.label, ROUTES); } } public View getView(int position, View convertView, ViewGroup parent) { LayoutInflater inflater = getLayoutInflater(); View row = inflater.inflate(R.layout.row, parent, false); TextView label = (TextView) row.findViewById(R.id.label); label.setText(ROUTES[position]); View icon = (View) row.findViewById(R.id.icon); switch(position){ case 0: icon.setBackgroundColor(R.color.Red); break; case 1: icon.setBackgroundColor(R.color.Red); break; case 2: icon.setBackgroundColor(R.color.Green); break; case 3: icon.setBackgroundColor(R.color.Green); break; case 4: icon.setBackgroundColor(R.color.Blue); break; case 5: icon.setBackgroundColor(R.color.Blue); break; } return(row); } } Any input is appreciated and if you have any questions don't hesitate to ask! Thanks, Rob

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  • facebook login problem

    - by khoyendra
    This is the code which is use for login in facebook but it is go to the finaly block and show my facebook link in browser. i am show from which it go to the finaly block in program. how to login without open browser this example is yack from http://code.google.com/p/facebook-java-api/wiki/Examples try{ MDC.put(ipAddress, req.getRemoteAddr()); HttpServletRequest request = (HttpServletRequest) req; HttpServletResponse response = (HttpServletResponse) res; HttpSession session = request.getSession(true); IFacebookRestClient<Document> userClient = getUserClient(session); if (userClient == null) { logger.debug("User session doesn't have a Facebook API client setup yet. Creating one and storing it in the user's session."); userClient = new FacebookXmlRestClient(api_key, secret); session.setAttribute(FACEBOOK_USER_CLIENT, userClient); } logger.trace("Creating a FacebookWebappHelper, which copies fb_ request param data into the userClient"); FacebookWebappHelper<Document> facebook = new FacebookWebappHelper<Document>(request, response, api_key, secret, userClient); String nextPage = request.getRequestURI(); nextPage = nextPage.substring(nextPage.indexOf("/", 1) + 1); //cut out the first /, the context path and the 2nd / logger.trace(nextPage); boolean redirectOccurred = facebook.requireLogin(nextPage); if (redirectOccurred) { return; //from this pt. send to finaly block and open my facebook page } redirectOccurred = facebook.requireFrame(nextPage); if (redirectOccurred) { return; } long facebookUserID; try { facebookUserID = userClient.users_getLoggedInUser(); } catch (FacebookException ex) { response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Error while fetching user's facebook ID"); logger.error("Error while getting cached (supplied by request params) value " + "of the user's facebook ID or while fetching it from the Facebook service " + "if the cached value was not present for some reason. Cached value = {}", userClient.getCacheUserId()); return; } MDC.put(facebookUserId, String.valueOf(facebookUserID)); chain.doFilter(request, response); } finally { MDC.remove(ipAddress); MDC.remove(facebookUserId); }

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  • How to declare and implement a COM interface on C# that inherits from another COM interface?

    - by Carlos Loth
    I'm trying to understand what is the correct why to implement COM interfaces from C# code. It is straightforward when the interface doesn't inherit from other base interface. Like this one: [ComImport, Guid("2047E320-F2A9-11CE-AE65-08002B2E1262"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] public interface IShellFolderViewCB { long MessageSFVCB(uint uMsg, int wParam, int lParam); } However things start to become weired when I need to implement an interface that inherits from other COM interfaces. For example, if I implement the IPersistFolder2 interface which inherits from IPersistFolder which inherits from IPersist as I usually on C# code: [ComImport, Guid("0000010c-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] public interface IPersist { void GetClassID([Out] out Guid classID); } [ComImport, Guid("000214EA-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] public interface IPersistFolder : IPersist { void Initialize([In] IntPtr pidl); } [ComImport, Guid("1AC3D9F0-175C-11d1-95BE-00609797EA4F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] public interface IPersistFolder2 : IPersistFolder { void GetCurFolder([Out] out IntPtr ppidl); } The operating system is not able to call the methods on my object implementation. When I'm debugging I can see the constructor of my IPersistFolder2 implementation is called many times, however the interface methods I've implemented aren't called. I'm implementing the IPersistFolder2 as follows: [Guid("A4603CDB-EC86-4E40-80FE-25D5F5FA467D")] public class PersistFolder: IPersistFolder2 { void IPersistFolder2.GetClassID(ref Guid classID) { ... } void IPersistFolder2.Initialize(IntPtr pidl) { ... } void IPersistFolder2.GetCurFolder(out IntPtr ppidl) { ... } } What seems strange is when I declare the COM interface imports as follow, it works: [ComImport, Guid("0000010c-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] internal interface IPersist { void GetClassID([Out] out Guid classID); } [ComImport, Guid("000214EA-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] internal interface IPersistFolder : IPersist { new void GetClassID([Out] out Guid classID); void Initialize([In] IntPtr pidl); } [ComImport, Guid("1AC3D9F0-175C-11d1-95BE-00609797EA4F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] internal interface IPersistFolder2 : IPersistFolder { new void GetClassID([Out] out Guid classID); new void Initialize([In] IntPtr pidl); void GetCurFolder([Out] out IntPtr ppidl); } I don't know why it works when I declare the COM interfaces that way (hidding the base interface methods using new). Maybe it is related to the way IUnknown works. Does anyone know what is the correct way of implementing COM interfaces in C# that inherits from other COM interfaces and why?

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  • Getting the executed output of an aspx page after a short delay

    - by Ankur
    Hi all, I have an aspx page which has some javascript code like <script> setTimeout("document.write('" + place.address + "');",1); </script> As it is clear from the code it will going to write something on the page after a very short delay of 1 ms. I have created an another page to get the page executed by some query string and get its output. The problem is I can not avoid the delay as simply writing document.write(place.address); will not print anything as it takes a little time to get values so if i set it in setTimeout for delayed output of 1 ms it always return me a value If I request the output from another page using System.Net.WebClient wc = new System.Net.WebClient(); System.IO.StreamReader sr = new System.IO.StreamReader(wc.OpenRead("http://localhost:4859/Default.aspx?lat=" + lat + "&lng=" + lng)); string strData = sr.ReadToEnd(); I get the source code of the document instead of the desired output can anyone help me out for either avoiding that delay or else delayed the client request ouput so that i get a desired value not the source code The js on default.aspx is <script type="text/javascript"> var geocoder; var address; function initialize() { geocoder = new GClientGeocoder(); var qs=new Querystring(); if(qs.get("lat") && qs.get("lng")) { geocoder.getLocations(new GLatLng(qs.get("lat"),qs.get("lng")),showAddress); } else { document.write("Invalid Access Or Not valid lat long is provided."); } } function getAddress(overlay, latlng) { if (latlng != null) { address = latlng; geocoder.getLocations(latlng, showAddress); } } function showAddress(r) { place = r.Placemark[0]; setTimeout("document.write('" + place.address + "');",1); //document.write(place.address); } </script> and the code on requestClient.aspx is as System.Net.WebClient wc = new System.Net.WebClient(); System.IO.StreamReader sr = new System.IO.StreamReader(wc.OpenRead("http://localhost:4859/Default.aspx?lat=" + lat + "&lng=" + lng)); string strData = sr.ReadToEnd();

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  • access exception when invoking method of an anonymous class using java reflection

    - by Asaf David
    Hello I'm trying to use an event dispatcher to allow a model to notify subscribed listeners when it changes. the event dispatcher receives a handler class and a method name to call during dispatch. the presenter subscribes to the model changes and provide a Handler implementation to be called on changes. Here's the code (I'm sorry it's a bit long). EventDispacther: package utils; public class EventDispatcher<T> { List<T> listeners; private String methodName; public EventDispatcher(String methodName) { listeners = new ArrayList<T>(); this.methodName = methodName; } public void add(T listener) { listeners.add(listener); } public void dispatch() { for (T listener : listeners) { try { Method method = listener.getClass().getMethod(methodName); method.invoke(listener); } catch (Exception e) { System.out.println(e.getMessage()); } } } } Model: package model; public class Model { private EventDispatcher<ModelChangedHandler> dispatcher; public Model() { dispatcher = new EventDispatcher<ModelChangedHandler>("modelChanged"); } public void whenModelChange(ModelChangedHandler handler) { dispatcher.add(handler); } public void change() { dispatcher.dispatch(); } } ModelChangedHandler: package model; public interface ModelChangedHandler { void modelChanged(); } Presenter: package presenter; public class Presenter { private final Model model; public Presenter(Model model) { this.model = model; this.model.whenModelChange(new ModelChangedHandler() { @Override public void modelChanged() { System.out.println("model changed"); } }); } } Main: package main; public class Main { public static void main(String[] args) { Model model = new Model(); Presenter presenter = new Presenter(model); model.change(); } } Now, I except to get the "model changed" message. However, I'm getting an java.lang.IllegalAccessException: Class utils.EventDispatcher can not access a member of class presenter.Presenter$1 with modifiers "public". I understand that the class to blame is the anonymous class i created inside the presenter, however I don't know how to make it any more 'public' than it currently is. If i replace it with a named nested class it seem to work. It also works if the Presenter and the EventDispatcher are in the same package, but I can't allow that (several presenters in different packages should use the EventDispatcher) any ideas?

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  • notification scheduling question

    - by sims
    Hi Stackers! I'm building an app that needs to send out notifications to users depending on user definable "notifications". So the notifications are not per event. They are arbitrary. A cron job should query the database and send out emails when it finds an event with matching criterion. The is a scheduling app. So naturally, one of the criterion is time. I think I've figured it out, but I'm sure there are better ideas out there as it seems to be a fairly common thing to do. I think I'll limit the users ability to "minutes before hand" to get notified as opposed to seconds or hours. So I have an eventA and notificationA. notificationA should be triggered if an event is due within 45 minutes. So eventA starts at 17:30. The user should be notified at 16:45. But the cron job might not run exactly at 00 seconds. So when the difference is not 45 minutes and 0 seconds it is, say, 45 minutes and 5 seconds. Notification time is past. Email doesn't get sent. User misses event. Shugar. We should also take into account that the cron job might take a long time to run. So maybe we should only trigger it every 5 minutes. So we need a bigger interval maybe. So then my guess would be to say that: if ((eventDueTime - now notificationTimeValue - interval) && (eventDueTime - now < notificationTimeValue + interval)) sendTheFrikinNotificationAlready(); It seems kind of risky if the there are thousands of notifications to send out. I guess I could make a thread for each notification and then a thread for each event that matches the criterion. That might help. Does that make sense? Any other ideas? Thanks!

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  • Should I use Python or Assembly for a super fast copy program

    - by PyNEwbie
    As a maintenance issue I need to routinely (3-5 times per year) copy a repository that is now has over 20 million files and exceeds 1.5 terabytes in total disk space. I am currently using RICHCOPY, but have tried others. RICHCOPY seems the fastest but I do not believe I am getting close to the limits of the capabilities of my XP machine. I am toying around with using what I have read in The Art of Assembly Language to write a program to copy my files. My other thought is to start learning how to multi-thread in Python to do the copies. I am toying around with the idea of doing this in Assembly because it seems interesting, but while my time is not incredibly precious it is precious enough that I am trying to get a sense of whether or not I will see significant enough gains in copy speed. I am assuming that I would but I only started really learning to program 18 months and it is still more or less a hobby. Thus I may be missing some fundamental concept of what happens with interpreted languages. Any observations or experiences would be appreciated. Note, I am not looking for any code. I have already written a basic copy program in Python 2.6 that is no slower than RICHCOPY. I am looking for some observations on which will give me more speed. Right now it takes me over 50 hours to make a copy from a disk to a Drobo and then back from the Drobo to a disk. I have a LogicCube for when I am simply duplicating a disk but sometimes I need to go from a disk to Drobo or the reverse. I am thinking that given that I can sector copy a 3/4 full 2 terabyte drive using the LogicCube in under seven hours I should be able to get close to that using Assembly, but I don't know enough to know if this is valid. (Yes, sometimes ignorance is bliss) The reason I need to speed it up is I have had two or three cycles where something has happened during copy (fifty hours is a long time to expect the world to hold still) that has caused me to have to trash the copy and start over. For example, last week the water main broke under our building and shorted out the power.

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  • Sending multiline message via sockets without closing the connection

    - by Yasir Arsanukaev
    Hello folks. Currently I have this code of my client-side Haskell application: import Network.Socket import Network.BSD import System.IO hiding (hPutStr, hPutStrLn, hGetLine, hGetContents) import System.IO.UTF8 connectserver :: HostName -- ^ Remote hostname, or localhost -> String -- ^ Port number or name -> IO Handle connectserver hostname port = withSocketsDo $ do -- withSocketsDo is required on Windows -- Look up the hostname and port. Either raises an exception -- or returns a nonempty list. First element in that list -- is supposed to be the best option. addrinfos <- getAddrInfo Nothing (Just hostname) (Just port) let serveraddr = head addrinfos -- Establish a socket for communication sock <- socket (addrFamily serveraddr) Stream defaultProtocol -- Mark the socket for keep-alive handling since it may be idle -- for long periods of time setSocketOption sock KeepAlive 1 -- Connect to server connect sock (addrAddress serveraddr) -- Make a Handle out of it for convenience h <- socketToHandle sock ReadWriteMode -- Were going to set buffering to LineBuffering and then -- explicitly call hFlush after each message, below, so that -- messages get logged immediately hSetBuffering h LineBuffering return h sendid :: Handle -> String -> IO String sendid h id = do hPutStr h id -- Make sure that we send data immediately hFlush h -- Retrieve results hGetLine h The code portions in connectserver are from this chapter of Real World Haskell book where they say: When dealing with TCP data, it's often convenient to convert a socket into a Haskell Handle. We do so here, and explicitly set the buffering – an important point for TCP communication. Next, we set up lazy reading from the socket's Handle. For each incoming line, we pass it to handle. After there is no more data – because the remote end has closed the socket – we output a message about that. Since hGetContents blocks until the server closes the socket on the other side, I used hGetLine instead. It satisfied me before I decided to implement multiline output to client. I wouldn't like the server to close a socket every time it finishes sending multiline text. The only simple idea I have at the moment is to count the number of linefeeds and stop reading lines after two subsequent linefeeds. Do you have any better suggestions? Thanks.

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  • file.createNewFile() creates files with last-modified time before actual creation time

    - by Kaleb Pederson
    I'm using JPoller to detect changes to files in a specific directory, but it's missing files because they end up with a timestamp earlier than their actual creation time. Here's how I test: public static void main(String [] files) { for (String file : files) { File f = new File(file); if (f.exists()) { System.err.println(file + " exists"); continue; } try { // find out the current time, I would hope to assume that the last-modified // time on the file will definitely be later than this System.out.println("-----------------------------------------"); long time = System.currentTimeMillis(); // create the file System.out.println("Creating " + file + " at " + time); f.createNewFile(); // let's see what the timestamp actually is (I've only seen it <time) System.out.println(file + " was last modified at: " + f.lastModified()); // well, ok, what if I explicitly set it to time? f.setLastModified(time); System.out.println("Updated modified time on " + file + " to " + time + " with actual " + f.lastModified()); } catch (IOException e) { System.err.println("Unable to create file"); } } } And here's what I get for output: ----------------------------------------- Creating test.7 at 1272324597956 test.7 was last modified at: 1272324597000 Updated modified time on test.7 to 1272324597956 with actual 1272324597000 ----------------------------------------- Creating test.8 at 1272324597957 test.8 was last modified at: 1272324597000 Updated modified time on test.8 to 1272324597957 with actual 1272324597000 ----------------------------------------- Creating test.9 at 1272324597957 test.9 was last modified at: 1272324597000 Updated modified time on test.9 to 1272324597957 with actual 1272324597000 The result is a race condition: JPoller records time of last check as xyz...123 File created at xyz...456 File last-modified timestamp actually reads xyz...000 JPoller looks for new/updated files with timestamp greater than xyz...123 JPoller ignores newly added file because xyz...000 is less than xyz...123 I pull my hair out for a while I tried digging into the code but both lastModified() and createNewFile() eventually resolve to native calls so I'm left with little information. For test.9, I lose 957 milliseconds. What kind of accuracy can I expect? Are my results going to vary by operating system or file system? Suggested workarounds? NOTE: I'm currently running Linux with an XFS filesystem. I wrote a quick program in C and the stat system call shows st_mtime as truncate(xyz...000/1000).

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  • Subroutine & GoTo design

    - by sub
    I have a strange question concerning subroutines: As I'm creating a minimal language and I don't want to add high-level loops like while or for I was planning on just adding gotos to keep it Turing-Complete. Now I thought, eww - gotos - I wouldn't want to program in that language if I had to use gotos so often. So I thought about adding subroutines instead. I see the difference as the following: gotos Go to (captain obvious) a previously defined point and continue executing the program from there. Leads to hardly understandable and buggy code, I think that's a fact. subroutines Similiar: You define their starting point somewhere, as you call them the program jumps there - but the subroutine can go back to the point it was called from with return. Okay. Why didn't I just add the more function-like, nice looking subroutines? Because: In order to make return work if I call subroutines from within subroutines from within other subroutines, I'd have to use a stack containing the point where the currently running subroutine came from at top. That would then mean that I would, if I create loops using the subroutines, end up with an extremely memory-eating, overflowing stack with return locations. Not good. Don't think of my subroutines as functions. They are just gotos that return to the point they were called from, they don't actually give back values like the return x; statement in nearly all today's languages. Now to my actual questions: How can I solve the above problem with the stack overflow on loops with subroutines? Do I have to add a separate goto language construct without the return option? Assembler doesn't have loops but as I have seen myJumpPoint:, jnz, jz, retn. That means to me that there must also be a stack containing all the return locations. Am I right with that? What about long running loops then? Don't they overflow the stack/eat memory then? Am I getting the retn symbol in assembler totally wrong? If yes, please explain it to me.

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  • MySQL table organization and optimization (Rails)

    - by aguynamedloren
    I've been learning Ruby on Rails over the past few months with no prior programming experience. Lately, I've been thinking about database optimization and table organization. I know there are great books on the subject, but I typically learn by example / as I go. Here's a hypothetical situation: Let's say I am building a social network for a niche community with 250,000 members (users). The users have the ability to attend events. Let's say there are 50,000 past/present/future events. Much like Facebook events, a user can attend any number of events and an event can have any number of attendees. In the database, there would be a table for users and a table for events. Somehow I would have to create an association between the users and events. I could create an "events" column in the users table such that each user row would contain a hash of event IDs, or I could create an "attendees" column in the events table such that each event row would contain a hash of user IDs. Neither of these solutions seem ideal, however. On a users profile page, I want to display the list of events they are associated with, which would require scanning the 50,000 event rows for the user ID of said user if I include an "attendees" column in the events table. Likewise, on an event page, I want to display a list of attendees for the event, which would require scanning the 250,000 user rows for the event ID of said event if I include an "events" column in the users table. Option 3 would be to create a third table that contains the attendee information for each and every event - but I don't see how this would solve any problems. Are these non-issues? Rails makes accessing all of this information easy, but I guess I'm worried about scale. It is entirely possible that I am under-estimating the speed and processing power of modern databases / servers / etc. How long would it take to scan 250,000 user rows for specific event IDs - 10ms? 100ms? 1,000ms? I guess that's not that bad. Am I just over-thinking this?

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  • How to salvage SQL server 2008 query from KILLED/ROLLBACK state?

    - by littlegreen
    I have a stored procedure that inserts batches of millions of rows, emerging from a certain query, into an SQL database. It has one parameter selecting the batch; when this parameter is omitted, it will gather a list of batches and recursively call itself, in order to iterate over batches. In (pseudo-)code, it looks something like this: CREATE PROCEDURE spProcedure AS BEGIN IF @code = 0 BEGIN ... WHILE @@Fetch_Status=0 BEGIN EXEC spProcedure @code FETCH NEXT ... INTO @code END END ELSE BEGIN -- Disable indexes ... INSERT INTO table SELECT (...) -- Enable indexes ... Now it can happen that this procedure is slow, for whatever reason: it can't get a lock, one of the indexes it uses is misdefined or disabled. In that case, I want to be able kill the procedure, truncate and recreate the resulting table, and try again. However, when I try and kill the procedure, the process frequently oozes into a KILLED/ROLLBACK state from which there seems to be no return. From Google I have learned to do an sp_lock, find the spid, and then kill it with KILL <spid>. But when I try to kill it, it tells me SPID 75: transaction rollback in progress. Estimated rollback completion: 0%. Estimated time remaining: 554 seconds. I did find a forum message hinting that another spid should be killed before the other one can start a rollback. But that didn't work for me either, plus I do not understand, why that would be the case... could it be because I am recursively calling my own stored procedure? (But it should be having the same spid, right?) In any case, my process is just sitting there, being dead, not responding to kills, and locking the table. This is very frustrating, as I want to go on developing my queries, not waiting hours on my server sitting dead while pretending to be finishing a supposed rollback. Is there some way in which I can tell the server not to store any rollback information for my query? Or not to allow any other queries to interfere with the rollback, so that it will not take so long? Or how to rewrite my query in a better way, or how kill the process successfully without restarting the server?

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  • Lifetime issue of IDisposable unmanaged resources in a complex object graph?

    - by stakx
    This question is about dealing with unmanaged resources (COM interop) and making sure there won't be any resource leaks. I'd appreciate feedback on whether I seem to do things the right way. Background: Let's say I've got two classes: A class LimitedComResource which is a wrapper around a COM object (received via some API). There can only be a limited number of those COM objects, therefore my class implements the IDisposable interface which will be responsible for releasing a COM object when it's no longer needed. Objects of another type ManagedObject are temporarily created to perform some work on a LimitedComResource. They are not IDisposable. To summarize the above in a diagram, my classes might look like this: +---------------+ +--------------------+ | ManagedObject | <>------> | LimitedComResource | +---------------+ +--------------------+ | o IDisposable (I'll provide example code for these two classes in just a moment.) Question: Since my temporary ManagedObject objects are not disposable, I obviously have no control over how long they'll be around. However, in the meantime I might have Disposed the LimitedComObject that a ManagedObject is referring to. How can I make sure that a ManagedObject won't access a LimitedComResource that's no longer there? +---------------+ +--------------------+ | managedObject | <>------> | (dead object) | +---------------+ +--------------------+ I've currently implemented this with a mix of weak references and a flag in LimitedResource which signals whether an object has already been disposed. Is there any better way? Example code (what I've currently got): LimitedComResource: class LimitedComResource : IDisposable { private readonly IUnknown comObject; // <-- set in constructor ... void Dispose(bool notFromFinalizer) { if (!this.isDisposed) { Marshal.FinalReleaseComObject(comObject); } this.isDisposed = true; } internal bool isDisposed = false; } ManagedObject: class ManagedObject { private readonly WeakReference limitedComResource; // <-- set in constructor ... public void DoSomeWork() { if (!limitedComResource.IsAlive()) { throw new ObjectDisposedException(); // ^^^^^^^^^^^^^^^^^^^^^^^ // is there a more suitable exception class? } var ur = (LimitedComResource)limitedComResource.Target; if (ur.isDisposed) { throw new ObjectDisposedException(); } ... // <-- do something sensible here! } }

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  • Having trouble getting MEF imports to be resolved

    - by Dave
    This is sort of a continuation of one of my earlier posts, which involves the resolving of modules in my WPF application. This question is specifically related to the effect of interdependencies of modules and the method of constructing those modules (i.e. via MEF or through new) on MEF's ability to resolve relationships. First of all, here is a simple UML diagram of my test application: I have tried two approaches: left approach: the App implements IError right approach: the App has a member that implements IError Left approach My code behind looked like this (just the MEF-related stuff): // app.cs [Export(typeof(IError))] public partial class Window1 : Window, IError { [Import] public CandyCo.Shared.LibraryInterfaces.IPlugin Plugin { get; set; } [Export] public CandyCo.Shared.LibraryInterfaces.ICandySettings Settings { get; set; } private ICandySettings Settings; public Window1() { // I create the preferences here with new, instead of using MEF. I wonder // if that's my whole problem? If I use MEF, and want to have parameters // going to the constructor, then do I have to [Export] a POCO (i.e. string)? Settings = new CandySettings( "Settings", @"c:\settings.xml"); var catalog = new DirectoryCatalog( "."); var container = new CompositionContainer( catalog); try { container.ComposeParts( this); } catch( CompositionException ex) { foreach( CompositionError e in ex.Errors) { string description = e.Description; string details = e.Exception.Message; } throw; } } } // plugin.cs [Export(typeof(IPlugin))] public class Plugin : IPlugin { [Import] public CandyCo.Shared.LibraryInterfaces.ICandySettings CandySettings { get; set; } [Import] public CandyCo.Shared.LibraryInterfaces.IError ErrorInterface { get; set; } [ImportingConstructor] public Plugin( ICandySettings candy_settings, IError error_interface) { CandySettings = candy_settings; ErrorInterface = error_interface; } } // candysettings.cs [Export(typeof(ICandySettings))] public class CandySettings : ICandySettings { ... } Right-side approach Basically the same as the left-side approach, except that I created a class that inherits from IError in the same assembly as Window1. I then used an [Import] to try to get MEF to resolve that for me. Can anyone explain how the two ways I have approached MEF here are flawed? I have been in the dark for so long that instead of reading about MEF and trying different suggestions, I've added MEF to my solution and am stepping into the code. The part where it looks like it fails is when it calls partManager.GetSavedImport(). For some reason, the importCache is null, which I don't understand. All the way up to this point, it's been looking at the part (Window1) and trying to resolve two imported interfaces -- IError and IPlugin. I would have expected it to enter code that looks at other assemblies in the same executable folder, and then check it for exports so that it knows how to resolve the imports...

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  • Provisioning api jpa

    - by user268515
    Hi i tried the following code Appsprovisioning.java public void calluser() throws AppsForYourDomainExceptiion IOException, { for(UserEntry userEntry : retrieveAllUsers().getEntries()) { m[x]= userEntry.getTitle().getPlainText(); x++; } try { for(int i=0;i<x;i++) { String sd=m[i]; stud greeting1 = new stud(sd); em.persist(greeting1); System.out.println("jk"); } } finally { em.close(); } public UserFeed retrieveAllUsers()throws ,ServiceException, IOException{ userService = new UserService("Myapplication"); userService.setUserCredentials("[email protected]","xxxxxxxx"); URL retrieveUrl = new URL("https://www.google.com/a/feeds/montfortperungudi.edu.in/user/2.0/"); UserFeed allUsers = new UserFeed(); UserFeed currentPage; Link nextLink; do { currentPage = userService.getFeed(retrieveUrl, UserFeed.class); allUsers.getEntries().addAll(currentPage.getEntries()); nextLink = currentPage.getLink(Link.Rel.NEXT, Link.Type.ATOM); if (nextLink != null) { retrieveUrl = new URL(nextLink.getHref()); } } while (nextLink != null); return allUsers; } } Servlet.java public class servlet extends HttpServlet { private static final long serialVersionUID = 1L; private static final Logger log = Logger.getLogger(servlet.class.getName()); // EntityManager em=null; AppsProvisioning aa=new AppsProvisioning(); public void doGet(HttpServletRequest req, HttpServletResponse resp)throws IOException { //em = EMFService.get().createEntityManager(); try { aa.calluser(); }catch(Exception e){ System.out.println("SEF "+e);} finally { // em.clear(); // em.close(); } } } Table Creation import javax.persistence.Entity; import javax.persistence.Id; @Entity(name="stud") public class stud { @Id private String fathername; public stud(String fathername) {// TODO Auto-generated constructor stub this.fathername=fathername; } public void setFathername(String fathername) { this.fathername = fathername; } public String getFathername() { return fathername; } } I cant able to store all the users in the table.. Its returning Session out error.

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  • What's the correct way to use Cakephp urls?

    - by Pichan
    Hello all, it's my first post here :) I'm having some difficulties with dealing with urls and parameters. I've gone through the router class api documentation over and over again and found nothing useful. First of all, I'd like to know if there is any 'universal' format in CakePHP(1.3) for handling urls. I'm currently handling all my urls as simple arrays(in the format that Router::url and $html-link accepts) and it's easy as long as I only need to pass them as arguments to cake's own methods. It usually gets tricky if I need something else. Mainly I'm having problems with converting string urls to the basic array format. Let's say I want to convert $arrayUrl to string and than again into url: $arrayUrl=array('controller'=>'SomeController','action'=>'someAction','someValue'); $url=Router::url($arrayUrl); //$url is now '/path/to/site/someController/someAction/someValue' $url=Router::normalize($url); //remove '/path/to/site' $parsed=Router::parse($url); /*$parsed is now Array( [controller] => someController [action] => someAction [named] => Array() [pass] => Array([0] => someValue) [plugin] => ) */ That seems an awful lot of code to do something as simple as to convert between 2 core formats. Also, note that $parsed is still not in the same as $arrayUrl. Of course I could tweak $parsed manually and actually I've done that a few times as a quick patch but I'd like to get to the bottom of this. I also noticed that when using prefix routing, $this-params in controller has the prefix embedded in the action(i.e. [action] = 'admin_edit') and the result of Router::parse() does not. Both of course have the prefix in it's own key. To summarize, how do I convert an url between any of these 3(or 4, if you include the prefix thing) mentioned formats the right way? Of course it would be easy to hack my way through this, but I'd still like to believe that cake is being developed by a bunch of people who have a lot more experience and insight than me, so I'm guessing there's a good reason for this "perceived misbehavior". I've tried to present my problem as good as I can, but due to my rusty english skills, I had to take a few detours :) I'll explain more if needed.

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  • Possible to do rounded corners in custom Progressbar progressDrawable?

    - by b-ryce
    I have a progress bar that is supposed to look like the attached image: And I've made it a long way. I'm very close the only part that isn't working is the rounded corners for the progressDrawable. Here is what mine looks like. (Notice, circled in red, that the fill inside the white outline does not have rounded corners): So, I've found a couple of ways to make this work when the progress bar is colored in with a shape, gradient, or color. BUT, I can't get it with an image as the progressDrawable. Here is my class that extends ProgressBar public class RoundedProgressBar extends ProgressBar{ private Paint paint; public RoundedProgressBar(Context context) { super(context); setup(); } public RoundedProgressBar(Context context, AttributeSet attrs) { super(context, attrs); setup(); } public RoundedProgressBar(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); setup(); ; } protected void setup() { paint = new Paint(); } @Override protected synchronized void onDraw(Canvas canvas) { // First draw the regular progress bar, then custom draw our text super.onDraw(canvas); paint.setColor(Color.WHITE); paint.setStyle(Paint.Style.STROKE); RectF r = new RectF(0,0,getWidth()-1,getHeight()-1); canvas.drawRoundRect(r,getHeight()/2,getHeight()/2, paint); } } Here is my selector: <layer-list xmlns:android="http://schemas.android.com/apk/res/android" > <item android:id="@android:id/background" android:drawable="@drawable/slider_track" /> <item android:id="@android:id/secondaryProgress" android:drawable="@drawable/slider_track" /> <item android:id="@android:id/progress" android:drawable="@drawable/slider_track_progress" /> </layer-list> Here are the images used in the selector: slider_track- slider_track_progress- Here is where I embed my progressbar in the layout for my activity <com.android.component.RoundedProgressBar android:id="@+id/player_hp_bar" android:layout_width="fill_parent" android:layout_height="36dip" android:layout_marginLeft="30dip" android:layout_marginRight="30dip" android:max="100" style="?android:attr/progressBarStyleHorizontal" android:progressDrawable="@drawable/slider_layer_list" android:progress="20" android:maxHeight="12dip" android:minHeight="12dip" /> Anyone know how to make this work?

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  • Transposing and Untransposing a String in java

    - by Will
    I have been working on two methods that will Transpose and Untranspose a String respectively. The solutions that I have come up with both work to the best of my knowledge. I just want to know if I could have solved these problems in a simpler way. My code seems like it is too long for the task that is being performed. The first method, transpose(), will take a String as a parameter and transpose it. If "bridge" is entered, the output will be "bergid". Likewise, with the unTranspose() method, if the user enters "bergid", the output will be "bridge". public void transpose( String s ) { String t = ""; int end = s.length() - 1; for ( int i = 0; i < s.length() / 2; i++ ) { t += Character.toString( s.charAt( i ) ) + Character.toString( s.charAt( end ) ); end--; } // Lenth of String is odd if ( s.length() % 2 == 1 ) { // add character in middle of String to the end of the new String t+= Character.toString( s.charAt( s.length() / 2 ) ); } System.out.println( t ); } public void unTranspose( String s ) { String t = ""; // Length of String is odd if ( s.length() % 2 == 1 ) { for ( int i = 0; i < s.length(); i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 2; i > 0; i -= 2 ) { t += Character.toString( s.charAt( i ) ); } System.out.println( t ); } // Length of String is even else if ( s.length() % 2 == 0 ) { for ( int i = 0; i < s.length() - 1; i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 1; i > 0; i -= 2 ) { t+= Character.toString( s.charAt( i ) ); } System.out.println( t ); } } My code looks horrible. I'm still not used to formatting my code correctly. Please bear with me. Thanks for your time

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  • How to produce precisely-timed tone and silence?

    - by Bob Denny
    I have a C# project that plays Morse code for RSS feeds. I write it using Managed DirectX, only to discover that Managed DirectX is old and deprecated. The task I have is to play pure sine wave bursts interspersed with silence periods (the code) which are precisely timed as to their duration. I need to be able to call a function which plays a pure tone for so many milliseconds, then Thread.Sleep() then play another, etc. At its fastest, the tones and spaces can be as short as 40ms. It's working quite well in Managed DirectX. To get the precisely timed tone I create 1 sec. of sine wave into a secondary buffer, then to play a tone of a certain duration I seek forward to within x milliseconds of the end of the buffer then play. I've tried System.Media.SoundPlayer. It's a loser because you have to Play(), Sleep(), then Stop() for arbitrary tone lengths. The result is a tone that is too long, variable by CPU load. It takes an indeterminate amount of time to actually stop the tone. I then embarked on a lengthy attempt to use NAudio 1.3. I ended up with a memory resident stream providing the tone data, and again seeking forward leaving the desired length of tone remaining in the stream, then playing. This worked OK on the DirectSoundOut class for a while (see below) but the WaveOut class quickly dies with an internal assert saying that buffers are still on the queue despite PlayerStopped = true. This is odd since I play to the end then put a wait of the same duration between the end of the tone and the start of the next. You'd think that 80ms after starting Play of a 40 ms tone that it wouldn't have buffers on the queue. DirectSoundOut works well for a while, but its problem is that for every tone burst Play() it spins off a separate thread. Eventually (5 min or so) it just stops working. You can see thread after thread after thread exiting in the Output window while running the project in VS2008 IDE. I don't create new objects during playing, I just Seek() the tone stream then call Play() over and over, so I don't think it's a problem with orphaned buffers/whatever piling up till it's choked. I'm out of patience on this one, so I'm asking in the hopes that someone here has faced a similar requirement and can steer me in a direction with a likely solution.

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  • Data access pattern, combining push and pull?

    - by andlju
    I need some advice on what kind of pattern(s) I should use for pushing/pulling data into my application. I'm writing a rule-engine that needs to hold quite a large amount of data in-memory in order to be efficient enough. I have some rather conflicting requirements; It is not acceptable for the engine to always have to wait for a full pre-load of all data before it is functional. Only fetching and caching data on-demand will lead to the engine taking too long before it is running quickly enough. An external event can trigger the need for specific parts of the data to be reloaded. Basically, I think I need a combination of pushing and pulling data into the application. A simplified version of my current "pattern" looks like this (in psuedo-C# written in notepad): // This interface is implemented by all classes that needs the data interface IDataSubscriber { void RegisterData(Entity data); } // This interface is implemented by the data access class interface IDataProvider { void EnsureLoaded(Key dataKey); void RegisterSubscriber(IDataSubscriber subscriber); } class MyClassThatNeedsData : IDataSubscriber { IDataProvider _provider; MyClassThatNeedsData(IDataProvider provider) { _provider = provider; _provider.RegisterSubscriber(this); } public void RegisterData(Entity data) { // Save data for later StoreDataInCache(data); } void UseData(Key key) { // Make sure that the data has been stored in cache _provider.EnsureLoaded(key); Entity data = GetDataFromCache(key); } } class MyDataProvider : IDataProvider { List<IDataSubscriber> _subscribers; // Make sure that the data for key has been loaded to all subscribers public void EnsureLoaded(Key key) { if (HasKeyBeenMarkedAsLoaded(key)) return; PublishDataToSubscribers(key); MarkKeyAsLoaded(key); } // Force all subscribers to get a new version of the data for key public void ForceReload(Key key) { PublishDataToSubscribers(key); MarkKeyAsLoaded(key); } void PublishDataToSubscribers(Key key) { Entity data = FetchDataFromStore(key); foreach(var subscriber in _subscribers) { subscriber.RegisterData(data); } } } // This class will be spun off on startup and should make sure that all data is // preloaded as quickly as possible class MyPreloadingThread { IDataProvider _provider; MyPreloadingThread(IDataProvider provider) { _provider = provider; } void RunInBackground() { IEnumerable<Key> allKeys = GetAllKeys(); foreach(var key in allKeys) { _provider.EnsureLoaded(key); } } } I have a feeling though that this is not necessarily the best way of doing this.. Just the fact that explaining it seems to take two pages feels like an indication.. Any ideas? Any patterns out there I should have a look at?

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