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  • Android Mediaplayer: setDataSource issue for downloaded media file

    - by Erik
    I have an application that will record and play audio files. Some of the audio files are downloaded using simple standard http downloads using httpclient. It worked like a charm for a long time. Now all of a sudden I cannot play the files I download. It fails with this stack. I store the files on the SDCard and I experience the problem both on a handset and a USB connected device. I have checked that the downloaded file is cool on the server, and I can play it without any issues. These are the code snippets I use ( I know that recordingFile is a valid path for the file). // inside the activity class private void playRecording() throws IOException{ File recordingFile = new File(recordingFileName); FileInputStream recordingInputStream = new FileInputStream(recordingFile); audioMediaPlayer.playAudio(recordingInputStream); } Here is the media player code: // inside my media player class which handles the recordings public void playAudio(FileInputStream audioInputStream) throws IOException { mediaPlayer.reset(); mediaPlayer.setDataSource(audioInputStream.getFD()); mediaPlayer.prepare(); mediaPlayer.start(); } Here is the exception: E/MediaPlayerService( 555): offset error E/MediaPlayer( 786): Unable to to create media player W/System.err( 786): java.io.IOException: setDataSourceFD failed.: status=0x80000000 W/System.err( 786): at android.media.MediaPlayer.setDataSource(Native Method) W/System.err( 786): at android.media.MediaPlayer.setDataSource(MediaPlayer.java:632) W/System.err( 786): at net.xxx.xxx.AudioMediaPlayer.playAudio(AudioMediaPlayer.java:69) W/System.err( 786): at net.xxx.xxx.Downloads.playRecording(Downloads.java:299) W/System.err( 786): at net.xxx.xxx.Downloads.access$0(Downloads.java:294) W/System.err( 786): at net.xxx.xxx.Downloads$1.onClick(Downloads.java:135) I have tried seeking some answer of the offset error, but not really clear what this issue might be. PS I download the file with this code: public FileOutputStream executeHttpGet(FileOutputStream fileOutputStream) throws ClientProtocolException, IOException{ try { // Execute HTTP Post Request httpResponse = httpClient.execute(httpPost, localContext); int status = httpResponse.getStatusLine().getStatusCode(); // we assume that the response body contains the error message if (status != HttpStatus.SC_OK) { ByteArrayOutputStream ostream = new ByteArrayOutputStream(); httpResponse.getEntity().writeTo(ostream); fileOutputStream = null; } else { InputStream content = httpResponse.getEntity().getContent(); byte[] buffer = new byte[1024]; int len = 0; while ( (len = content.read(buffer)) > 0 ) { fileOutputStream.write(buffer,0, len); } fileOutputStream.close(); content.close(); // this will also close the connection } } catch (ClientProtocolException e1) { // TODO Auto-generated catch block e1.printStackTrace(); fileOutputStream = null; } catch (IOException e2) { // TODO Auto-generated catch block e2.printStackTrace(); fileOutputStream = null; } return fileOutputStream; }

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  • Parallax backgrounds in OpenGL ES on the iPhone

    - by Scott
    I've got basically a 2d game on the iPhone and I'm trying to set up multiple backgrounds that scroll at different speeds (known as parallax backgrounds). So my thought was to just stick the backgrounds BEHIND the foreground using different z-coordinate planes, and just make them bigger than the foreground (in size) to accommodate, so that the whole thing can be scrolled (just at a different speed). And (as far as I know) I basically implemented that. The only problem is that it seems to entirely ignore whatever z-value I give it, or rather it just zeroes all of them. I see the background (I've only tested ONE background so far, to keep it simple...so for now I just have a foreground and I want one background scrolling at a different speed), but it scrolls 1:1 with my foreground, so it obviously doesn't look right, and most of it is cut off (cause it's bigger). And I've tried various z-values for the background and various near/far clipping planes...it's always the same. I'm probably just doing one simple thing wrong, but I can't figure it out. I'm wondering if it has to do with me using only 2 coordinates in glVertexPointer for the foreground? (Of course for the background I AM passing in 3) I'll post some code: This is some initial setup: glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrthof(-1.0f, 1.0f, -1.5f, 1.5f, -10.0f, 10.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glEnableClientState(GL_VERTEX_ARRAY); //glEnableClientState(GL_COLOR_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); //transparency glEnable (GL_BLEND); glBlendFunc (GL_ONE, GL_ONE_MINUS_SRC_ALPHA); A little bit about my foreground's float array....it's interleaved. For my foreground it goes vertex x, vertex y, texture x, texture y, repeat. This all works just fine. This is my FOREGROUND rendering: glVertexPointer(2, GL_FLOAT, 4*sizeof(GLfloat), texes); <br> glTexCoordPointer(2, GL_FLOAT, 4*sizeof(GLfloat), (GLvoid*)texes + 2*sizeof(GLfloat)); <br> glDrawArrays(GL_TRIANGLES, 0, indexCount / 4); BACKGROUND rendering: Same drill here except this time it goes vertex x, vertex y, vertex z, texture x, texture y, repeat. Note the z value this time. I did make sure the data in this array was correct while debugging (getting the right z values). And again, it shows up...it's just not going far back in the distance like it should. glVertexPointer(3, GL_FLOAT, 5*sizeof(GLfloat), b1Texes); glTexCoordPointer(2, GL_FLOAT, 5*sizeof(GLfloat), (GLvoid*)b1Texes + 3*sizeof(GLfloat)); glDrawArrays(GL_TRIANGLES, 0, b1IndexCount / 5); And to move my camera, I just do a simple glTranslatef(x, y, 0.0f); I'm not understanding what I'm doing wrong cause this seems like the most basic 3D function imaginable...things further away are smaller and don't move as fast when the camera moves. Not the case for me. Seems like it should be pretty basic and not even really be affected by my projection and all that (though I've even tried doing glFrustum just for fun, no success). Please help, I feel like it's just one dumb thing. I will post more code if necessary.

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  • HttpWebRequest: How to find a postal code at Canada Post through a WebRequest with x-www-form-enclos

    - by Will Marcouiller
    I'm currently writing some tests so that I may improve my skills with the Internet interaction through Windows Forms. One of those tests is to find a postal code which should be returned by Canada Post website. My default URL setting is set to: http://www.canadapost.ca/cpotools/apps/fpc/personal/findByCity?execution=e4s1 The required form fields are: streetNumber, streetName, city, province The contentType is "application/x-www-form-enclosed" EDIT: Please consider the value "application/x-www-form-encoded" instead of point 3 value as the contentType. (Thanks EricLaw-MSFT!) The result I get is not the result expected. I get the HTML source code of the page where I could manually enter the information to find the postal code, but not the HTML source code with the found postal code. Any idea of what I'm doing wrong? Shall I consider going the XML way? Is it first of all possible to search on Canada Post anonymously? Here's a code sample for better description: public static string FindPostalCode(ICanadadianAddress address) { var postData = string.Concat(string.Format("&streetNumber={0}", address.StreetNumber) , string.Format("&streetName={0}", address.StreetName) , string.Format("&city={0}", address.City) , string.Format("&province={0}", address.Province)); var encoding = new ASCIIEncoding(); byte[] postDataBytes = encoding.GetBytes(postData); request = (HttpWebRequest)WebRequest.Create(DefaultUrlSettings); request.ImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Anonymous; request.Container = new CookieContainer(); request.Timeout = 10000; request.ContentType = contentType; request.ContentLength = postDataBytes.LongLength; request.Method = @"post"; var senderStream = new StreamWriter(request.GetRequestStream()); senderStream.Write(postDataBytes, 0, postDataBytes.Length); senderStream.Close(); string htmlResponse = new StreamReader(request.GetResponse().GetResponseStream()).ReadToEnd(); return processedResult(htmlResponse); // Processing the HTML source code parsing, etc. } I seem stuck in a bottle neck in my point of view. I find no way out to the desired result. EDIT: There seems to have to parameters as for the ContentType of this site. Let me explain. There's one with the "meta"-variables which stipulates the following: meta http-equiv="Content-Type" content="application/xhtml+xml, text/xml, text/html; charset=utf-8" And another one later down the code that is read as: form id="fpcByAdvancedSearch:fpcSearch" name="fpcByAdvancedSearch:fpcSearch" method="post" action="/cpotools/apps/fpc/personal/findByCity?execution=e1s1" enctype="application/x-www-form-urlencoded" My question is the following: With which one do I have to stick? Let me guess, the first ContentType is to be considered as the second is only for another request to a function or so when the data is posted? EDIT: As per request, the closer to the solution I am is listed under this question: WebRequest: How to find a postal code using a WebRequest against this ContentType=”application/xhtml+xml, text/xml, text/html; charset=utf-8”? Thanks for any help! :-)

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  • Asp.net MVC and MOSS 2010 integration

    - by Robert Koritnik
    Just a sidenote: I'm not sure whether I should post this to serverfault as well, because some MOSS admin may have some info for me as well? A bit of explanation first (without Asp.net MVC) Is it possible to integrate the two? Is it possible to write an application that would share at least credential information with MOSS? I have to write a MOSS application that has to do with these technologies: MOSS 2010 Personal client certificates authentication (most probably on USB keys) Active Directory Federation Services Separate SQL DB that would serve application specific data (separate as not being part of MOSS DB) How should it work? Users should authenticate using personal certificates into MOSS 2010 There would be a certain part of MOSS that would be related to my custom application This application should only authorize certain users via AD FS - I guess these users should have a certain security claim attached to them This application should manage users (that have access to this app) with additional (app specific) security claims related to this application (as additional application level authorization rights for individual application parts) This application should use custom SQL 2008 DB heavily with its own data This application should have the possibility to integrate with external systems as well (Exchange for instance to inject calendar entries, ERP systems etc) This application should be able to export its data (from its DB) to files. I don't know if it's possible, but it would be nice if the app could add these files to MOSS and attach authorization info to them so only users with sufficient rights would be able to view/open these files. Why Asp.net MVC then? I'm very well versed in Asp.net MVC (also with the latest version) and I haven't done anything on Sharepoint since version 2003 (which doesn't do me no good or prepare me for the latest version in any way shape or form). This project will most probably be a death march project so I would rather write my application as a UI rich Asp.net MVC application and somehow integrate it into MOSS. But not only via a link, because I would like to at least share credentials, so users wouldn't need to re-login when accessing my app. Using Asp.net MVC I would at least have the possibility to finish on time or be less death marching. Is this at all possible? Questions Is it possible to integrate Asp.net MVC into MOSS as described above? If integration is not possible, would it be possible to create a completely MOSS based application that would work as described? Which parts of MOSS 2010 should I use to accomplish what I need?

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  • Silverlight Image Loading Question

    - by Matt
    I'm playing around with Silverlight Images and a listbox. Here's the scenario. Using WCF I grab some images out of my database and, using a custom class, add items to a listbox. It's working great right now. The images load and appear in the listbox, just like I want them to. I want to refine and improve my control just a little more so here's what I've done. <ListBox x:Name="lbMedia" Background="Transparent" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Auto"> <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <c:WrapPanel></c:WrapPanel> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> <ItemsControl.ItemTemplate> <DataTemplate> <im:MediaManagerItem></im:MediaManagerItem> </DataTemplate> </ItemsControl.ItemTemplate> </ListBox> Just a simple listbox. The datatemplate is a custom control and literally it contains a contentpresenter, nothing more. Now the class that I use as the ItemSource has a Source property. Here's what it looks like. private UIElement _LoadingSource; private UIElement _Source; public UIElement Source { get { if( _Source == null ) { LoadMedia(); return new LoadingElement(); } return _Source; } set { if( !( value is Image ) && !( value is MediaElement ) ) throw new Exception( "Media Source must be an Image or MediaElement" ); _Source = value; NotifyPropertyChanged( "Source" ); } } Essentially, on the get I check if the image/video has been loaded from the server. If it hasn't I return a loading control, then I proceed to load my image. Here's the code for my LoadMedia method. private void LoadMedia() { if( _Media != null && _Media.MediaId > 0 ) { //load the media BackgroundWorker mediaLoader = new BackgroundWorker(); mediaLoader.DoWork += mediaLoader_DoWork; mediaLoader.RunWorkerCompleted += mediaLoader_RunWorkerCompleted; mediaLoader.RunWorkerAsync(); } } void mediaLoader_RunWorkerCompleted( object sender, RunWorkerCompletedEventArgs e ) { if(_LoadingSource != null) Source = _LoadingSource; } void mediaLoader_DoWork( object sender, DoWorkEventArgs e ) { string url = App.siteUrl + "download.ashx?MediaId=" + _Media.MediaId; SmartDispatcher.BeginInvoke( () => { Image img = new Image(); img.Source = new BitmapImage( new Uri( url, UriKind.Absolute ) ); _LoadingSource = img; } ); } So as the code goes, I create a new image element, and set the Uri. The images that I'm downloading take about 2-5 seconds to download. Now for the problem / fine tuning. Right now my code will check if the source is null and if it is, return a loading element, and run the background worker to get the image. Once the background worker finishes, set the source to the new downloaded image. I want to be able to set the Source property AFTER the image has fully downloaded. Right now my loading element appears for a brief second, then there's nothing for 2-5 seconds until the image finishes downloading. I want the loading elements to stick around until the image is completely ready but I'm having troubles doing this. I've tried adding a a listener to the ImageOpened event and update the Source property then, but it doesn't work. Thanks in advance.

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  • problem with two .NET threads and hardware access

    - by mack369
    I'm creating an application which communicates with the device via FT2232H USB/RS232 converter. For communication I'm using FTD2XX_NET.dll library from FTDI website. I'm using two threads: first thread continuously reads data from the device the second thread is the main thread of the Windows Form Application I've got a problem when I'm trying to write any data to the device while the receiver's thread is running. The main thread simply hangs up on ftdiDevice.Write function. I tried to synchronize both threads so that only one thread can use Read/Write function at the same time, but it didn't help. Below code responsible for the communication. Note that following functions are methods of FtdiPort class. Receiver's thread private void receiverLoop() { if (this.DataReceivedHandler == null) { throw new BackendException("dataReceived delegate is not set"); } FTDI.FT_STATUS ftStatus = FTDI.FT_STATUS.FT_OK; byte[] readBytes = new byte[this.ReadBufferSize]; while (true) { lock (FtdiPort.threadLocker) { UInt32 numBytesRead = 0; ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead); if (ftStatus == FTDI.FT_STATUS.FT_OK) { this.DataReceivedHandler(readBytes, numBytesRead); } else { Trace.WriteLine(String.Format("Couldn't read data from ftdi: status {0}", ftStatus)); Thread.Sleep(10); } } Thread.Sleep(this.RXThreadDelay); } } Write function called from main thread public void Write(byte[] data, int length) { if (this.IsOpened) { uint i = 0; lock (FtdiPort.threadLocker) { this.ftdiDevice.Write(data, length, ref i); } Thread.Sleep(1); if (i != (int)length) { throw new BackendException("Couldnt send all data"); } } else { throw new BackendException("Port is closed"); } } Object used to synchronize two threads static Object threadLocker = new Object(); Method that starts the receiver's thread private void startReceiver() { if (this.DataReceivedHandler == null) { return; } if (this.IsOpened == false) { throw new BackendException("Trying to start listening for raw data while disconnected"); } this.receiverThread = new Thread(this.receiverLoop); //this.receiverThread.Name = "protocolListener"; this.receiverThread.IsBackground = true; this.receiverThread.Start(); } The ftdiDevice.Write function doesn't hang up if I comment following line: ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead);

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  • In Ruby, how to I read memory values from an external process?

    - by grg-n-sox
    So all I simply want to do is make a Ruby program that reads some values from known memory address in another process's virtual memory. Through my research and basic knowledge of hex editing a running process's x86 assembly in memory, I have found the base address and offsets for the values in memory I want. I do not want to change them; I just want to read them. I asked a developer of a memory editor how to approach this abstract of language and assuming a Windows platform. He told me the Win32API calls for OpenProcess, CreateProcess, ReadProcessMemory, and WriteProcessMemory were the way to go using either C or C++. I think that the way to go would be just using the Win32API class and mapping two instances of it; One for either OpenProcess or CreateProcess, depending on if the user already has th process running or not, and another instance will be mapped to ReadProcessMemory. I probably still need to find the function for getting the list of running processes so I know which running process is the one I want if it is running already. This would take some work to put all together, but I am figuring it wouldn't be too bad to code up. It is just a new area of programming for me since I have never worked this low level from a high level language (well, higher level than C anyways). I am just wondering of the ways to approach this. I could just use a bunch or Win32API calls, but that means having to deal with a bunch of string and array pack and unpacking that is system dependant I want to eventually make this work cross-platform since the process I am reading from is produced from an executable that has multiple platform builds, (I know the memory address changes from system to system. The idea is to have a flat file that contains all memory mappings so the Ruby program can just match the current platform environment to the matching memory mapping.) but from the looks of things I'll just have to make a class that wraps whatever is the current platform's system shared library memory related function calls. For all I know, there could already exist a Ruby gem that takes care of all of this for me that I am just not finding. I could also possibly try editing the executables for each build to make it so whenever the memory values I want to read from are written to by the process, it also writes a copy of the new value to a space in shared memory that I somehow have Ruby make an instance of a class that is a pointer under the hood to that shared memory address and somehow signal to the Ruby program that the value was updated and should be reloaded. Basically a interrupt based system would be nice, but since the purpose of reading these values is just to send to a scoreboard broadcasted from a central server, I could just stick to a polling based system that sends updates at fixed time intervals. I also could just abandon Ruby altogether and go for C or C++ but I do not know those nearly as well. I actually know more x86 than C++ and I only know C as far as system independent ANSI C and have never dealt with shared system libraries before. So is there a gem or lesser known module available that has already done this? If not, then any additional information as to how to accomplish this would be nice. I guess, long story short, how do I do all this? Thanks in advance, Grg PS: Also a confirmation that those Win32API calls should be aimed at the kernel32.dll library would be nice.

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  • Both tab & hover triggered popups problem

    - by carpenter
    I am trying to display divs when hovering over thumb-nails and/or both when tabbing onto them. If I stick to my mouse, the popups seem to work OK - if I start with a tab press I can show the popops also (foward only - no shift + tab yet). Any help getting them to play well together? <script type="text/javascript"> // Note: the below is being run from an onmouseover on a asp:HyperLink at the moment function onhovering_and_tabbingon2() { var active_hover = 0; var num_of_thumb; // set the default focus onto the first thumb-nail and make its popup display document.getElementById('link_no' + active_hover).focus(); // set focus on the first thumb $('#pop' + active_hover).toggleClass('popup'); // show its popup as it is hidden // for when hovering over the thumbs $(".box img").hover( // so as to effect only images/thumb-nails within divs of class=box when hovering over them function () { // test for if the image is a thumb-entry and not a popup image - of class=thumbs2 thumb = $(this).attr('class'); if (thumb != "thumbs2") { // I need to add/toggle the class here to a "div" and not to the image being hovered on, a div with text that corrosponds to the hovered on image though // so grab the number of the thumb_entry - to use to id the div. num_of_thumb = $(this).attr('id').replace('thumb_entry_No', ''); // find the div with id 'pop' + num_of_thumb, and toggleClass on it $('#pop' + num_of_thumb).toggleClass('popup'); // shows the hovered on pic's popup // move the focus to the hovered on pic's a tag ?????? document.getElementById('link_no' + num_of_thumb).focus(); // if the previous popup that was showing was in box2.. if (active_hover == 1 || active_hover% 2 == 1) { $('#pop' + active_hover).toggleClass('popup4_line2'); } else { // remove/toggle the previous active popup's visibility $('#pop' + active_hover).toggleClass('popup'); } // set the new active_hover to num_of_thumb active_hover = num_of_thumb; } }, function () { } ); // same thing again - but for my second row/line of entries/thumb-nails... $(".box2 img").hover( // so as to effect only images/thumbs within divs of class=box2 function () { // test if the image is a thumb-entry and not a popup image thumb = $(this).attr('class'); if (thumb != "thumbs2") { // I need to add the class here to a "div" and not to the image being hovered on, a div that corrosponds to the hovered on image though // so grab the number of the thumb_entry being hovered on, so as to id the div. num_of_thumb = $(this).attr('id').replace('thumb_entry_No', ''); // find the div with id='pop' + num_of_thumb, and toggleClass on it $('#pop' + num_of_thumb).toggleClass('popup4_line2'); // move the focus to the hovered on pic's a tag ?? document.getElementById('link_no' + num_of_thumb).focus(); // if the previous popup that was showing was in box.. // or if the active_hover is even (modulus) if (active_hover == 0 || active_hover % 2 == 0) { $('#pop' + active_hover).toggleClass('popup'); } else { // remove the previous active visible popup $('#pop' + active_hover).toggleClass('popup4_line2'); } // set the new active_hover to num_of_thumb active_hover = num_of_thumb; } }, function () { } ); // todo: I would like to try to show the popups when tabbing through the thumb-nails also // but am lost... document.onkeyup = keypress; // ???? function keypress() { // alert("The key pressed was: " + window.event.keyCode); if (window.event.keyCode == "9") { //alert("The tab key was pressed!"); active_hover = active_hover + 1; // for tabbing into box 2 (odd numbers) if (active_hover == 1 || active_hover % 2 == 1) { // toggle visibility of previous popup $('#pop' + (active_hover - 1)).toggleClass('popup'); // toggle visibility of current popup $('#pop' + active_hover).toggleClass('popup4_line2'); // } else { // for tabbing into box from box2 // toggle visibility of previous popup $('#pop' + (active_hover - 1)).toggleClass('popup4_line2'); // toggle visibility of current popup $('#pop' + active_hover).toggleClass('popup'); // } // ?????? // // if (window.event.keyCode == "shift&9") { } } } } </script>

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  • Paging, sorting and filtering in a stored procedure (SQL Server)

    - by Fruitbat
    I was looking at different ways of writing a stored procedure to return a "page" of data. This was for use with the asp ObjectDataSource, but it could be considered a more general problem. The requirement is to return a subset of the data based on the usual paging paremeters, startPageIndex and maximumRows, but also a sortBy parameter to allow the data to be sorted. Also there are some parameters passed in to filter the data on various conditions. One common way to do this seems to be something like this: [Method 1] ;WITH stuff AS ( SELECT CASE WHEN @SortBy = 'Name' THEN ROW_NUMBER() OVER (ORDER BY Name) WHEN @SortBy = 'Name DESC' THEN ROW_NUMBER() OVER (ORDER BY Name DESC) WHEN @SortBy = ... ELSE ROW_NUMBER() OVER (ORDER BY whatever) END AS Row, ., ., ., FROM Table1 INNER JOIN Table2 ... LEFT JOIN Table3 ... WHERE ... (lots of things to check) ) SELECT * FROM stuff WHERE (Row > @startRowIndex) AND (Row <= @startRowIndex + @maximumRows OR @maximumRows <= 0) ORDER BY Row One problem with this is that it doesn't give the total count and generally we need another stored procedure for that. This second stored procedure has to replicate the parameter list and the complex WHERE clause. Not nice. One solution is to append an extra column to the final select list, (SELECT COUNT(*) FROM stuff) AS TotalRows. This gives us the total but repeats it for every row in the result set, which is not ideal. [Method 2] An interesting alternative is given here (http://www.4guysfromrolla.com/articles/032206-1.aspx) using dynamic SQL. He reckons that the performance is better because the CASE statement in the first solution drags things down. Fair enough, and this solution makes it easy to get the totalRows and slap it into an output parameter. But I hate coding dynamic SQL. All that 'bit of SQL ' + STR(@parm1) +' bit more SQL' gubbins. [Method 3] The only way I can find to get what I want, without repeating code which would have to be synchronised, and keeping things reasonably readable is to go back to the "old way" of using a table variable: DECLARE @stuff TABLE (Row INT, ...) INSERT INTO @stuff SELECT CASE WHEN @SortBy = 'Name' THEN ROW_NUMBER() OVER (ORDER BY Name) WHEN @SortBy = 'Name DESC' THEN ROW_NUMBER() OVER (ORDER BY Name DESC) WHEN @SortBy = ... ELSE ROW_NUMBER() OVER (ORDER BY whatever) END AS Row, ., ., ., FROM Table1 INNER JOIN Table2 ... LEFT JOIN Table3 ... WHERE ... (lots of things to check) SELECT * FROM stuff WHERE (Row > @startRowIndex) AND (Row <= @startRowIndex + @maximumRows OR @maximumRows <= 0) ORDER BY Row (Or a similar method using an IDENTITY column on the table variable). Here I can just add a SELECT COUNT on the table variable to get the totalRows and put it into an output parameter. I did some tests and with a fairly simple version of the query (no sortBy and no filter), method 1 seems to come up on top (almost twice as quick as the other 2). Then I decided to test probably I needed the complexity and I needed the SQL to be in stored procedures. With this I get method 1 taking nearly twice as long as the other 2 methods. Which seems strange. Is there any good reason why I shouldn't spurn CTEs and stick with method 3? UPDATE - 15 March 2012 I tried adapting Method 1 to dump the page from the CTE into a temporary table so that I could extract the TotalRows and then select just the relevant columns for the resultset. This seemed to add significantly to the time (more than I expected). I should add that I'm running this on a laptop with SQL Server Express 2008 (all that I have available) but still the comparison should be valid. I looked again at the dynamic SQL method. It turns out I wasn't really doing it properly (just concatenating strings together). I set it up as in the documentation for sp_executesql (with a parameter description string and parameter list) and it's much more readable. Also this method runs fastest in my environment. Why that should be still baffles me, but I guess the answer is hinted at in Hogan's comment.

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  • Clear data at serial port in Linux in C?

    - by ipkiss
    Hello guys, I am testing the sending and receiving programs with the code as The main() function is below: include include include include include include include "read_write.h" int fd; int initport(int fd) { struct termios options; // Get the current options for the port... tcgetattr(fd, &options); // Set the baud rates to 19200... cfsetispeed(&options, B9600); cfsetospeed(&options, B9600); // Enable the receiver and set local mode... options.c_cflag |= (CLOCAL | CREAD); options.c_cflag &= ~PARENB; options.c_cflag &= ~CSTOPB; options.c_cflag &= ~CSIZE; options.c_cflag |= CS8; // Set the new options for the port... tcsetattr(fd, TCSANOW, &options); return 1; } int main(int argc, char **argv) { fd = open("/dev/pts/2", O_RDWR | O_NOCTTY | O_NDELAY); if (fd == -1) { perror("open_port: Unable to open /dev/pts/1 - "); return 1; } else { fcntl(fd, F_SETFL, 0); } printf("baud=%d\n", getbaud(fd)); initport(fd); printf("baud=%d\n", getbaud(fd)); char sCmd[254]; sCmd[0] = 0x41; sCmd[1] = 0x42; sCmd[2] = 0x43; sCmd[3] = 0x00; if (!writeport(fd, sCmd)) { printf("write failed\n"); close(fd); return 1; } printf("written:%s\n", sCmd); usleep(500000); char sResult[254]; fcntl(fd, F_SETFL, FNDELAY); if (!readport(fd,sResult)) { printf("read failed\n"); close(fd); return 1; } printf("readport=%s\n", sResult); close(fd); return 0; } read_write.h: #include <stdio.h> /* Standard input/output definitions */ include /* String function definitions */ include /* UNIX standard function definitions */ include /* File control definitions */ include /* Error number definitions */ include /* POSIX terminal control definitions */ int writeport(int fd, char *chars) { int len = strlen(chars); chars[len] = 0x0d; // stick a after the command chars[len+1] = 0x00; // terminate the string properly int n = write(fd, chars, strlen(chars)); if (n < 0) { fputs("write failed!\n", stderr); return 0; } return 1; } int readport(int fd, char *result) { int iIn = read(fd, result, 254); result[iIn-1] = 0x00; if (iIn < 0) { if (errno == EAGAIN) { printf("SERIAL EAGAIN ERROR\n"); return 0; } else { printf("SERIAL read error %d %s\n", errno, strerror(errno)); return 0; } } return 1; } and got the issue: In order to test with serial port, I used the socat (https://help.ubuntu.com/community/VirtualSerialPort ) to create a pair serial ports on Linux and test my program with these port. The first time the program sends the data and the program receives data is ok. However, if I read again or even re-write the new data into the serial port, the return data is always null until I stop the virtual serial port and start it again, then the write and read data is ok, but still, only one time. (In the real case, the sending part will be done by another device, I am just taking care of the reading data from the serial port. I wrote both parts just to test my reading code.) Does anyone have any ideas? Thanks a lot.

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  • How do I evaluate my skillset against the current market to see what needs improvement and where my

    - by baijajusav
    First of all, this question may be out of bounds for this site. If so, remove it. I say this because this site seems to be a place for more concrete questions that are not so relative in nature. And before I begin, for those of you whom just prefer a question and not this sort of dialog, here is my question: How can I assess my current skills as a programmer and decide where and what areas to improve upon? That said, here's what I'm asking/talking about, in essence. The market is always in constant flux. As programmers we're always having to learn new things, update our skills, push ourselves into that next project. There's not a very good litmus test that I know of for us to get an idea of where we stand as programmers. I came across this blog post by Jeff Atwood talking about why can't programmers code. Instinctively (and as the post goes on to state) I rushed through the program in about 4 minutes (most of that time was b/c I was hand writing it out. Still, this doesn't really answer the question of where do my skills need to be to succeed in today's world. I real blogs, listen to podcasts, try to keep up on the latest things coming out. It has only been in the past couple of months that I made a decision to pick a focus area for my learning as I can't learn everything and trying to do so is to spread myself too thin. I chose ASP.NET MVC & C#. I plan to stick with Microsoft technologies, not out of some sense of loyalty or stubbornness, but rather because they seem to stream together and have a unifying connection between them. With Windows Phone 7 coming out, it seems that now is the obvious time to pick up WPF and Silverlight as well. Still, if you asked me to code something apart from intellisense and the internet, I probably couldn't get the syntax right. I don't have libraries memorized or know precisely where the classes I use exist within the .Net framework, namely because I haven't had to pull that knowledge out of the air. In a way, I suppose Visual Studio has insulated me, which isn't a good thing, but, at the same time, I've still been able to be productive. I'm working on my own side project to try and help my learning. In doing so, I'm trying to make use of best practices and 3rd party frameworks where I can. I'm using automapper and EF 1.0. I know everyone in the .net community seems to cry foul at the sound of EF 1.0, but I can't say why because I've never used it. There's no lazy loading and that has proven rather annoying; however, aside from that, I haven't had that much of an issue. Granted this is probably because I'm not writing tests as I go (which I'm not doing because I don't know how to test EF in tests and don't really have a clue how to write tests for ASP.NET MVC 1.0). I'm also using a custom membership provider; granted, it's a barebone implementation, but I'm using it still. My thinking in all of this is, while I am neglecting a great many important technologies that are in the mainstream, I'll have a working project in the end. I can come back and add those things after I finish. Doing it all now and at once seems like too much. I know how I work and I don't think I'd ever get it done that way. I've elected to make this a community wiki as I think this question might fight better there. If a moderator disagrees with that choice or the decision to post this here, the just delete the question. I'm not trying to make undue work for anyone. I'm just a programmer trying to assess my where his skills are now and where I should be improving.

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  • VBA nested Loop flow control

    - by PCGIZMO
    I will be brief and stick to what I know. This code for the most part works as it should. The only issue is in the iteration of the x and z loop. these to loops should set the range and yLABEL for the Y loop. I can get through a set and come up with the correct range after that things go bonkers. I know some of it has to do with not breaking out of x to set z and then back to x update the range. It should work z is found then x. the range between them is set for y. then next x but y stays then rang between y and x is set for y.. so on and so forth kinda like a slinky down the stairs. or a slide rule depending on how I set the loops either way I end up all over the place after a couple iterations. I have done a few things but each time I break out of x to set z , X restarts at the top of the range. At least that's what I think I am seeing. In the example sheet i have since changed the way the way the offset works with the loop but the idea is still the same. I have goto statements at this time i was going to try figuring out conditional switches after the loops were working. Any help direction or advice is appreciated. Option Explicit Sub parse() Application.DisplayAlerts = False 'Application.EnableCancelKey = xlDisabled Dim strPath As String, strPathused As String strPath = "C:\clerk plan2" Dim objfso As FileSystemObject, objFolder As Folder, objfile As Object Set objfso = CreateObject("Scripting.FileSystemObject") Set objFolder = objfso.GetFolder(strPath) 'Loop through objWorkBooks For Each objfile In objFolder.Files If objfso.GetExtensionName(objfile.Path) = "xlsx" Then Dim objWorkbook As Workbook Set objWorkbook = Workbooks.Open(objfile.Path) ' Set path for move to at end of script strPathused = "C:\prodplan\used\" & objWorkbook.Name objWorkbook.Worksheets("inbound transfer sheet").Activate objWorkbook.Worksheets("inbound transfer sheet").Cells.UnMerge 'Range management WB Dim SRCwb As Worksheet, SRCrange1 As Range, SRCrange2 As Range, lastrow As Range Set SRCwb = objWorkbook.Worksheets("inbound transfer sheet") Set SRCrange1 = SRCwb.Range("g3:g150") Set SRCrange2 = SRCwb.Range("a1:a150") Dim DSTws As Worksheet Set DSTws = Workbooks("clerkplan2.xlsm").Worksheets("transfer") Dim STR1 As String, STR2 As String, xVAL As String, zVAL As String, xSTR As String, zSTR As String STR1 = "INBOUND TRANS" STR2 = "INBOUND CA TRANS" Dim x As Variant, z As Variant, y As Variant, zxRANGE As Range For Each z In SRCrange2 zSTR = Mid(z, 1, 16) If zSTR <> STR2 Then GoTo zNEXT If zSTR = STR2 Then zVAL = z End If For Each x In SRCrange2 xSTR = Mid(x, 1, 13) If xSTR <> STR1 Then GoTo xNEXT If xSTR = STR1 Then xVAL = x End If Dim yLABEL As String If xVAL = x And zVAL = z Then If x.Row > z.Row Then Set zxRANGE = SRCwb.Range(x.Offset(1, 0).Address & " : " & z.Offset(-1, 0).Address) yLABEL = z.Value Else Set zxRANGE = SRCwb.Range(z.Offset(-1, 0).Address & " : " & x.Offset(1, 0).Address) yLABEL = x.Value End If End If MsgBox zxRANGE.Address ' DEBUG For Each y In zxRANGE If y.Offset(0, 6) = "Temp" Or y.Offset(0, 14) = "Begin Time" Or y.Offset(0, 15) = "End Time" Or _ Len(y.Offset(0, 6)) = 0 Or Len(y.Offset(0, 14)) = 0 Or Len(y.Offset(0, 15)) = "0" Then yNEXT Set lastrow = Workbooks("clerkplan2.xlsm").Worksheets("transfer").Range("c" & DSTws.Rows.Count).End(xlUp).Offset(1, 0) y.Offset(0, 6).Copy lastrow.PasteSpecial Paste:=xlPasteValues, operation:=xlNone, skipblanks:=True, Transpose:=False DSTws.Activate ActiveCell.Offset(0, -1) = objWorkbook.Name ActiveCell.Offset(0, -2) = yLABEL objWorkbook.Activate y.Offset(0, 14).Copy Set lastrow = Workbooks("clerkplan2.xlsm").Worksheets("transfer").Range("d" & DSTws.Rows.Count).End(xlUp).Offset(1, 0) lastrow.PasteSpecial Paste:=xlPasteValues, operation:=xlNone, skipblanks:=True, Transpose:=False objWorkbook.Activate y.Offset(0, 15).Copy Set lastrow = Workbooks("clerkplan2.xlsm").Worksheets("transfer").Range("e" & DSTws.Rows.Count).End(xlUp).Offset(1, 0) lastrow.PasteSpecial Paste:=xlPasteValues, operation:=xlNone, skipblanks:=True, Transpose:=False yNEXT: Next y xNEXT: Next x zNEXT: Next z strPathused = "C:\clerk plan2\used\" & objWorkbook.Name objWorkbook.Close False 'Move proccesed file to new Dir Dim OldFilePath As String Dim NewFilePath As String OldFilePath = objfile 'original file location NewFilePath = strPathused ' new file location Name OldFilePath As NewFilePath ' move the file End If Next End Sub

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  • Looking for a function that will split profits/loss equally between 2 business partners.

    - by Hamish Grubijan
    This is not homework, for I am not a student. This is for my general curiosity. I apologize if I am reinventing the wheel here.The function I seek can be defined as follows (language agnostic): int getPercentageOfA(double moneyA, double workA, double moneyB, double workB) { // Perhaps you may assume that workA == 0 // Compute result return result; } Suppose Alice and Bob want to do business together ... such as ... selling used books. Alice is only interested in investing money in it and nothing else. Bob might invest some money, but he might have no $ available to invest. He will, however, put in the effort in finding a seller, a buyer, and doing maintenance. There are no tools, education, health insurance costs, or other expenses to consider. Both Alice and Bob wish to split the profits "equally" (A different weight like 40/60 for advanced users). Both are entrepreneurs, so they deal with low ROI/wage, and high income alike. There is no fixed wage, minimum wage, fixed ROI, or minimum ROI. They try to find the best deal possible, assume risks and go for it. Now, let's stick with the 50/50 model. If Alice invests $100, Bob invests work, and they will end up with a profit (or loss) of $60, they will split it equally - either both get $30 for their efforts/investments, or Bob ends up owing $30 to Alice. A second possibility: Both Alice and Bob invest 100, then Bob does all the work, and they end up splitting $60 profit. It looks like Alice should get only $15, because $30 of that profit came from Bob's investment and Bob's effort, so Alice shall have none of it, and the other $30 is to be split 50/50. Both of the examples above are trivial even when A and B want to split it 35/65 or what have you. Now it gets more complicated: What if Alice invests $70, and Bob invests $30 + does all of the work. It appears simple: (70,30) = (30,30) + (40,0) ... but, if only we knew how to weigh the two parts relative to each other. Another complicated (I think) example: what if Alice and Bob invest $70 and $30 respectively, and also put in an equal amount of work? I have a few data points: When A and B put in the same amount of work and the same $ - 50/50. When A puts in 100% of the money, and B does 100% of the work - 50/50. When A does all of the work and puts in all of the money - 100 for A / 0 for B (and vice-versa). When A puts in 50% of the money, and B puts in 50% of the money as well as does all of the work - 25 for A, and 75 for B (and vice-versa). If I fix things such that always workA = 0%, workB = 100% of the total work, then getPercentageOfA becomes a function: height z given x and y. The question is - how do you extrapolate this function between these several points? What is this function? If you can cover the cases when workA does not have to be 0% of the total work, and when investment vs work is split as 85/15 or using some other model, then what would the new function be?

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  • Error when opening .tar.gz via Shell to install Apache Maven

    - by adamsquared
    Thank you in advance for the help. My Goal: To install apache maven per its websites instructions (http://maven.apache.org/download.html), in order to install the JUNG package according to its install instructions (http://sourceforge.net/apps/trac/jung/wiki/JUNGManual), so I can use the JUNG classes in various Java GUIs. The Problem: I get an error message when I try to extract the apache-maven .gz (install?) file in shell. Background: I'm trying to install the JUNG (http://jung.sourceforge.net/index.html) package to my system's Java, so I can write object-oriented code using various GUIs (Ecliplse, Dr. Java) using the classes in JUNG. I don't understand how the building/installing process works, and how I can get what I build/install to work on various GUIs and the command line. I'm new to shell and the command line, and mostly have experience using a simple IDE (DrJava, Python IDLE, R GUI) to write and compile object-oriented code. Machine: Mac OSX 10.5.8 32-bit. The Instructions: For the maven building Extract the distribution archive, i.e. apache-maven-3.0.4-bin.tar.gz to the directory you wish to install Maven 3.0.4. These instructions assume you chose /usr/local/apache-maven. The subdirectory apache-maven-3.0.4 will be created from the archive. ... for the JUNG installation Appendix: How to Build JUNG This is a brief intro to building JUNG jars with maven2 (the build system that JUNG currently uses). First, ensure that you have a JDK of at least version 1.5: JUNG 2.0+ requires Java 1.5+. Ensure that your JAVA_HOME variable is set to the location of the JDK. On a Windows platform, you may have a separate JRE (Java Runtime Environment) and JDK (Java Development Kit). The JRE has no capability to compile Java source files, so you must have a JDK installed. If your JAVA_HOME variable is set to the location of the JRE, and not the location of the JDK, you will be unable to compile. Get Maven Download and install maven2 from maven.apache.org: http://maven.apache.org/download.html At time of writing (early December 2009), the latest version was maven-2.2.1. Install the downloaded maven2 (there are installation instructions on the Maven website). Follow the installation instructions and confirm a successful installation by typing 'mvn --version' in a command terminal window. Get JUNG ... What I Did: I downloaded the file apache-maven-2.2.1-bin.tar.gz. The JUNG website specified to use apache maven 2. I wanted to stick to the recommended installation instructions, but I couldn't get to /usr on my GUI (i've noticed you click on the MacHD symbol on the desktop its missing several directories/folders that you can see using the shell using the ls command at root directory I couldn't find a way to access the file using my mac GUI. Therefore, I used the shell to navigate to the root directory and then to /usr/local, and used the mkdir command to make the directory apache-maven and entered it. I then moved the file using the mv command. Next I tried extracting the file using tar -zxvf apache-maven-2.2.1-bin.tar.gz. The Error Message: tar: apache-maven-2.2.1/direcoryandfile: Cannot open: No such file or directory ... apache-maven-2.2.1/lib/ext: Cannot mkdir: No such file or directory apache-maven-2.2.1/lib/ext/README.txt tar: apache-maven-2.2.1/lib/ext/README.txt: Cannot open: No such file or directory tar: Error exit delayed from previous errors From what I can tell the archive file is missing some directories or something. I tried deleting the file, redownloading the .tar.gz file from a different mirror and repeating the process. Same result. Thanks again for the help

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  • Why is cell phone software still so primitive?

    - by Tomislav Nakic-Alfirevic
    I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones: full text search: searches all address book contents, messages, anything else being a plus better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.) bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone) no multitasking capabilities worth mentioning and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now. To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer. What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up? Edit: I believe a clarification on the multitasking point might be beneficial. I'll use my phone as an example, although the point is much more general. The phone can multitask and in fact does: you can listen to music and do something else at the same time. On the other hand, the way the software has been designed makes multitasking next to useless. (Ditto with the external touch screen: it can take touch commands, but only one application makes use of it, and only with 3 commands.) To take the multitasking example to the extreme, if I plug my phone into my laptop and it registers as an external disk, it doesn't allow any kind of operation: messages, calling, calendar, everything out of reach, although I can receive a call. No "battery life" issue there: it's charging while connected. BTW, another example of design below the current state of the art: I don't see a phone on the horizon which will remember where in an audio or video file you were when you stopped listening/watching it last time (podcasts are a good use case). Simplistic rewind/fast forward functionality only aggravates the problem.

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  • C# problem with two threads and hardware access

    - by mack369
    I'm creating an application which communicates with the device via FT2232H USB/RS232 converter. For communication I'm using FTD2XX_NET.dll library from FTDI website. I'm using two threads: first thread continuously reads data from the device the second thread is the main thread of the Windows Form Application I've got a problem when I'm trying to write any data to the device while the receiver's thread is running. The main thread simply hangs up on ftdiDevice.Write function. I tried to synchronize both threads so that only one thread can use Read/Write function at the same time, but it didn't help. Below code responsible for the communication. Note that following functions are methods of FtdiPort class. Receiver's thread private void receiverLoop() { if (this.DataReceivedHandler == null) { throw new BackendException("dataReceived delegate is not set"); } FTDI.FT_STATUS ftStatus = FTDI.FT_STATUS.FT_OK; byte[] readBytes = new byte[this.ReadBufferSize]; while (true) { lock (FtdiPort.threadLocker) { UInt32 numBytesRead = 0; ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead); if (ftStatus == FTDI.FT_STATUS.FT_OK) { this.DataReceivedHandler(readBytes, numBytesRead); } else { Trace.WriteLine(String.Format("Couldn't read data from ftdi: status {0}", ftStatus)); Thread.Sleep(10); } } Thread.Sleep(this.RXThreadDelay); } } Write function called from main thread public void Write(byte[] data, int length) { if (this.IsOpened) { uint i = 0; lock (FtdiPort.threadLocker) { this.ftdiDevice.Write(data, length, ref i); } Thread.Sleep(1); if (i != (int)length) { throw new BackendException("Couldnt send all data"); } } else { throw new BackendException("Port is closed"); } } Object used to synchronize two threads static Object threadLocker = new Object(); Method that starts the receiver's thread private void startReceiver() { if (this.DataReceivedHandler == null) { return; } if (this.IsOpened == false) { throw new BackendException("Trying to start listening for raw data while disconnected"); } this.receiverThread = new Thread(this.receiverLoop); //this.receiverThread.Name = "protocolListener"; this.receiverThread.IsBackground = true; this.receiverThread.Start(); } The ftdiDevice.Write function doesn't hang up if I comment following line: ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead);

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  • surfaceDestroyed called out of turn

    - by Avasulthiris
    I'm currently developing on minimum sdk version 3 (Android 1.5 - cupcake) and I'm having a strange unexplained issue that I have not been able to solve on my own. It is now becoming a rather urgent issue as I've already missed 1 deadline... I'm writing a high-level library to make long term android development easier and quicker. The one specific module has to capture images for a application... I've gotten everything right so far over the last couple months, except this one little thing and I don't know what to do any more: When I use the Camera object and implement a SurfaceHolder.Callback, the methods surfaceCreated() and surfaceChanged() are called one after the other. Then when the activity finishes, surfaceDestroyed() is called. This is how it should be, but when I stick the exact same code in my library (plain Java library that references the Android API - not in an activity), surfaceDestroyed() is called directly after created and changed. As a result - the camera object is closed before I can use it and the application force closes. What a pain. I can't do anything! This method call is controlled by the device.. Why does the surface close for no reason? Even when I post it to run on the activity thread through my own invokeAndWait(Runnable) method, like I do for many other things. I have 5 different working examples of different ways and implementations of capturing images in android but I still get the same issue when I plug it into my library. I don't understand what the difference is. The code is pretty much the same - and I post all the related code to the UI thread so its not a thread handling issue or anything like that. I've rewritten it about 20 times in different ways - same issue every time.. The only other way to approach it that I know of is creating a new Camera and setting it to the VideoView. The android source (c++ native code) however provides no Camera constructor, only an open() method which automatically forwards the camera's state to 'prepared' but I can only set the camera to the VideoView from the 'initialized' state. Pretty silly, I know, but there is no way around it unless I modify the Android library source code haha. not an option! The API does not allow for this method - you are expected to use it like my first example. So essentially - i just need to understand exactly why surfaceDestroyed() is called out of turn and if there is anything I can do to avoid it closing? If i can just understand the exact logic behind it and how it works! The documentation isn't much help! Secondly, if someone knows of any alternative ways to do it, as my second example, but hopefully one which the API actually allows for? haha Thanks guys. I would post code, but its fairly complicated, a couple thousand lines for this specific class and it would probably take a couple days to explain with all the threading and event listeners and what not. I just need help with this 1 single thing. Please let me know if you have any questions.

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  • Data munging and data import scripting

    - by morpheous
    I need to write some scripts to carry out some tasks on my server (running Ubuntu server 8.04 TLS). The tasks are to be run periodically, so I will be running the scripts as cron jobs. I have divided the tasks into "group A" and "group B" - because (in my mind at least), they are a bit different. Task Group A import data from a file and possibly reformat it - by reformatting, I mean doing things like santizing the data, possibly normalizing it and or running calculations on 'columns' of the data Import the munged data into a database. For now, I am mostly using mySQL for the vast majority of imports - although some files will be imported into a sqlLite database. Note: The files will be mostly text files, although some of the files are in a binary format (my own proprietary format, written by a C++ application I developed). Task Group B Extract data from the database Perform calculations on the data and either insert or update tables in the database. My coding experience is is primarily as a C/C++ developer, although I have been using PHP as well for the last 2 years or so. I am from a windows background so I am still finding my feet in the linux environment. My question is this - I need to write scripts to perform the tasks I described above. Although I suppose I could write a few C++ applications to be used in the shell scripts, I think it may be better to write them in a scripting language (maybe this is a flawed assumption?). My thinking is that it would be easier to modify thins in a script - no need to rebuild etc for changes to functionality. Additionally, C++ data munging in C++ tends to involve more lines of code than "natural" scripting languages such as Perl, Python etc. Assuming that the majority of people on here agree that scripting is the way to go, herein lies my dilema. Which scripting language to use to perform the tasks above (giving my background). My gut instinct tells me that Perl (shudder) would be the most obvious choice for performing all of the above tasks. BUT (and that is a big BUT). The mere mention of Perl makes my toes curl, as I had a very, very bag experience with it a while back. The syntax seems quite unnatural to me - despite how many times I have tried to learn it - so if possible, I would really like to give it a miss. PHP (which I already know), also am not sure is a good candidate for scripting on the CLI (I have not seen many examples on how to do this etc - so I may be wrong). The last thing I must mention is that IF I have to learn a new language in order to do this, I cannot afford (time constraint) to spend more than a day, in learning the key commands/features required in order to do this (I can always learn the details of the language later, once I have actually deployed the scripts). So, which scripting language would you recommend (PHP, Python, Perl, [insert your favorite here]) - and most importantly WHY?. Or, should I just stick to writing little C++ applications that I call in a shell script?. Lastly, if you have suggested a scripting language, can you please show with a FEW lines (Perl mongers - I'm looking in your direction [nothing to cryptic!] ;) ) how I can use the language you suggested to do what I want to do. Hopefully, the lines you present will convince me that it can be done easily and elegantly in the language you suggested.

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  • How to listen for file system changes MAC - kFSEventStreamCreateFlagWatchRoot

    - by Cocoa Newbie
    Hi All, I am listening for Directory and disk changes in a COCOA project using FSEvents. I need to get events when a root folder is renamed or deleted. So, I passed kFSEventStreamCreateFlagWatchRoot while creating the FSEventStream.But even if I delete or rename the root folder I am not getting corresponding FSEventStreamEventFlags. Any idea what could possibly be the issue. I am listening for changes in a USB mounted device. I used both FSEventStreamCreate and FSEventStreamCreateRelativeToDevice. One thing I notices is when I try with FSEventStreamCreate I get the following error message while creating FSEventStream: (CarbonCore.framework) FSEventStreamCreate: watch_all_parents: error trying to add kqueue for fd 7 (/Volumes/NO NAME; Operation not supported) But with FSEventStreamCreateRelativeToDevice there are no errors but still not getting kFSEventStreamEventFlagRootChanged in event flags. Also, while creation using FSEventStreamCreateRelativeToDevice apple say's if I want to listen to root path changes pass emty string "". But I am not able to listen to root path changes by passing empty string. But when I pass "/" it works. But even for "/" I do not get any proper FSEventStreamEventFlags. I am pasting the code here: -(void) subscribeFileSystemChanges:(NSString*) path { PRINT_FUNCTION_BEGIN; // if already subscribed then unsubscribe if (stream) { FSEventStreamStop(stream); FSEventStreamInvalidate(stream); /* will remove from runloop */ FSEventStreamRelease(stream); } FSEventStreamContext cntxt = {0}; cntxt.info = self; CFArrayRef pathsToWatch = CFArrayCreate(NULL, (const void**)&path, 1, NULL); stream = FSEventStreamCreate(NULL, &feCallback, &cntxt, pathsToWatch, kFSEventStreamEventIdSinceNow, 1, kFSEventStreamCreateFlagWatchRoot ); FSEventStreamScheduleWithRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode); FSEventStreamStart(stream); } call back function: static void feCallback(ConstFSEventStreamRef streamRef, void* pClientCallBackInfo, size_t numEvents, void* pEventPaths, const FSEventStreamEventFlags eventFlags[], const FSEventStreamEventId eventIds[]) {? char** ppPaths = (char**)pEventPaths; int i; for (i = 0; i < numEvents; i++) { NSLog(@"Event Flags %lu Event Id %llu", eventFlags[i], eventIds[i]); NSLog(@"Path changed: %@", [NSString stringWithUTF8String:ppPaths[i]]); } } Thanks a lot in advance.

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  • MBR status confusion

    - by Ahmed Ghoneim
    EB 58 90 6D 6B 64 6F 73 66 73 00 00 02 08 20 00 02 00 00 00 00 F8 00 00 3E 00 83 00 00 00 00 00 94 88 7E 00 98 1F 00 00 00 00 00 00 02 00 00 00 01 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 29 A9 38 B1 34 57 61 76 65 20 20 20 20 20 20 20 46 41 54 33 32 20 20 20 0E 1F BE 77 7C AC 22 C0 74 0B 56 B4 0E BB 07 00 CD 10 5E EB F0 32 E4 CD 16 CD 19 EB FE 54 68 69 73 20 69 73 20 6E 6F 74 20 61 20 62 6F 6F 74 61 62 6C 65 20 64 69 73 6B 2E 20 20 50 6C 65 61 73 65 20 69 6E 73 65 72 74 20 61 20 62 6F 6F 74 61 62 6C 65 20 66 6C 6F 70 70 79 20 61 6E 64 0D 0A 70 72 65 73 73 20 61 6E 79 20 6B 65 79 20 74 6F 20 74 72 79 20 61 67 61 69 6E 20 2E 2E 2E 20 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 AA Learning disk records, this is my USB MBR record viewed by bless on ubuntu formatted with disk utility as MBR table and FAT partition, referring to this Wiki of first record status (0x80 = bootable (active), 0x00 = non-bootable, other = invalid ) but my MBR shows first offset as EB. What's this record stands for ? also, can you provide me with good tables/images tutorials for MBR and other disks' records :)

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  • Strategies for "Always-Connected" Windows Client Data Architecture

    - by magz2010
    Hi. Let me start by saying: this is my 1st post here, this is a bit lenghty, and I havent done Windows Forms development in years....with that in mind please excuse me if this isn't directly a programming question and please bear with me as I really need the help!! I have been asked to develop a Windows Forms app for our company that talks to a central (local area network) Linux Server hosting a PostgreSQL database. The app is to allow users to authenticate themselves into the system and thereafter conduct the usual transactions with the PG database. Ordinarily, I would propose writing a webforms app against Mono, but the clients need to utilise local resources such as USB peripheral devices, so that is out of the question. While it might not seem clear, my questions are italised below: Dilemma #1: The application is meant to be always connected. How should I structure my DAL/BLL - Should this reside on the server or with the client? Dilemma #2: I have been reading up on Client Application Services (CAS), and it seems like a great fit for authentication, as everything is exposed via URIs. I know that a .NET Data Provider exists for PostgreSQL, but not too sure if CAS will all work on a Linux (Debian) server? Believe me, I would get my hands dirty and try myself, but I need to come up with a logical design first before resources are allocated to me for "trial purposes"! Dilemma #3: If the DAL/BLL is to reside on the server, is there any way I can create data services, and expose only these services to authenticated clients. There is a (security) requirement whereby a connection string with username and password to the database cannot be present on any client machines...even if security on the database side is quite rigid. I'm guessing that the only way for this to work would be to create the various CRUD data service methods that are exposed by an ASP.NET app, and have the WindowsForms make a request for data or persist data to the ASP.NET app (thru a URI) and have that return a resultset or value. Would I be correct in assuming this? Should I be looking into WCF Data Services? and will WCF work with a non-SQL Server database? Thank you for taking the time out to read this, but know that I am desperately seeking any advice on this! THANKS A MILLION!!!!

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  • How best to modernize the 2002-era J2EE app?

    - by user331465
    I have this friend.... I have this friend who works on a java ee application (j2ee) application started in the early 2000's. Currently they add a feature here and there, but have a large codebase. Over the years the team has shrunk by 70%. [Yes, the "i have this friend is". It's me, attempting to humorously inject teenage high-school counselor shame into the mix] Java, Vintage 2002 The application uses EJB 2.1, struts 1.x, DAO's etc with straight jdbc calls (mixture of stored procedures and prepared statements). No ORM. For caching they use a mixture of OpenSymphony OSCache and a home-grown cache layer. Over the last few years, they have spent effort to modernize the UI using ajax techniques and libraries. This largely involves javascript libaries (jquery, yui, etc). Client Side On the client side, the lack of upgrade path from struts1 to struts2 discouraged them from migrating to struts2. Other web frameworks became popular (wicket, spring , jsf). Struts2 was not the "clear winner". Migrating all the existing UI from Struts1 to Struts2/wicket/etc did not seem to present much marginal benefit at a very high cost. They did not want to have a patchwork of technologies-du-jour (subsystem X in Struts2, subsystem Y in Wicket, etc.) so developer write new features using Struts 1. Server Side On the server side, they looked into moving to ejb 3, but never had a big impetus. The developers are all comfortable with ejb-jar.xml, EJBHome, EJBRemote, that "ejb 2.1 as is" represented the path of least resistance. One big complaint about the ejb environment: programmers still pretend "ejb server runs in separate jvm than servlet engine". No app server (jboss/weblogic) has ever enforced this separation. The team has never deployed the ejb server on a separate box then the app server. The ear file contains multiple copies of the same jar file; one for the 'web layer' (foo.war/WEB-INF/lib) and one for the server side (foo.ear/). The app server only loads one jar. The duplications makes for ambiguity. Caching As for caching, they use several cache implementations: OpenSymphony cache and a homegrown cache. Jgroups provides clustering support Now What? The question: The team currently has spare cycles to to invest in modernizing the application? Where would the smart investor spend them? The main criteria: 1) productivity gains. Specifically reducing the time to develope new subsystems features and reduced maintenance. 2) performance/scalability. They do not care about fashion or techno-du-jour street cred. What do you all recommend? On the persistence side Switch everything (or new development only) to JPA/JPA2? Straight hibernate? Wait for Java EE 6? On the client/web-framework side: Migrate (some or all) to struts2? wicket? jsf/jsf2? As for caching: terracotta? ehcache? coherence? stick with what they have? how best to take advantage of the huge heap sizes that the 64-bit jvms offer? Thanks in advance.

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  • Determining if Memory Pointer is Valid - C++

    - by Jim Fell
    It has been my observation that if free( ptr ) is called where ptr is not a valid pointer to system-allocated memory, an access violation occurs. Let's say that I call free like this: LPVOID ptr = (LPVOID)0x12345678; free( ptr ); This will most definitely cause an access violation. Is there a way to test that the memory location pointed to by ptr is valid system-allocated memory? It seems to me that the the memory management part of the Windows OS kernel must know what memory has been allocated and what memory remains for allocation. Otherwise, how could it know if enough memory remains to satisfy a given request? (rhetorical) That said, it seems reasonable to conclude that there must be a function (or set of functions) that would allow a user to determine if a pointer is valid system-allocated memory. Perhaps Microsoft has not made these functions public. If Microsoft has not provided such an API, I can only presume that it was for an intentional and specific reason. Would providing such a hook into the system prose a significant threat to system security? Situation Report Although knowing whether a memory pointer is valid could be useful in many scenarios, this is my particular situation: I am writing a driver for a new piece of hardware that is to replace an existing piece of hardware that connects to the PC via USB. My mandate is to write the new driver such that calls to the existing API for the current driver will continue to work in the PC applications in which it is used. Thus the only required changes to existing applications is to load the appropriate driver DLL(s) at startup. The problem here is that the existing driver uses a callback to send received serial messages to the application; a pointer to allocated memory containing the message is passed from the driver to the application via the callback. It is then the responsibility of the application to call another driver API to free the memory by passing back the same pointer from the application to the driver. In this scenario the second API has no way to determine if the application has actually passed back a pointer to valid memory.

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  • C++ Optimize if/else condition

    - by Heye
    I have a single line of code, that consumes 25% - 30% of the runtime of my application. It is a less-than comparator for an std::set (the set is implemented with a Red-Black-Tree). It is called about 180 Million times within 52 seconds. struct Entry { const float _cost; const long _id; // some other vars Entry(float cost, float id) : _cost(cost), _id(id) { } }; template<class T> struct lt_entry: public binary_function <T, T, bool> { bool operator()(const T &l, const T &r) const { // Most readable shape if(l._cost != r._cost) { return r._cost < l._cost; } else { return l._id < r._id; } } }; The entries should be sorted by cost and if the cost is the same by their id. I have many insertions for each extraction of the minimum. I thought about using Fibonacci-Heaps, but I have been told that they are theoretically nice, but suffer from high constants and are pretty complicated to implement. And since insert is in O(log(n)) the runtime increase is nearly constant with large n. So I think its okay to stick to the set. To improve performance I tried to express it in different shapes: return l._cost < r._cost || r._cost > l._cost || l._id < r._id; return l._cost < r._cost || (l._cost == r._cost && l._id < r._id); Even this: typedef union { float _f; int _i; } flint; //... flint diff; diff._f = (l._cost - r._cost); return (diff._i && diff._i >> 31) || l._id < r._id; But the compiler seems to be smart enough already, because I haven't been able to improve the runtime. I also thought about SSE but this problem is really not very applicable for SSE... The assembly looks somewhat like this: movss (%rbx),%xmm1 mov $0x1,%r8d movss 0x20(%rdx),%xmm0 ucomiss %xmm1,%xmm0 ja 0x410600 <_ZNSt8_Rb_tree[..]+96> ucomiss %xmm0,%xmm1 jp 0x4105fd <_ZNSt8_Rb_[..]_+93> jne 0x4105fd <_ZNSt8_Rb_[..]_+93> mov 0x28(%rdx),%rax cmp %rax,0x8(%rbx) jb 0x410600 <_ZNSt8_Rb_[..]_+96> xor %r8d,%r8d I have a very tiny bit experience with assembly language, but not really much. I thought it would be the best (only?) point to squeeze out some performance, but is it really worth the effort? Can you see any shortcuts that could save some cycles? The platform the code will run on is an ubuntu 12 with gcc 4.6 (-stl=c++0x) on a many-core intel machine. Only libraries available are boost, openmp and tbb. I am really stuck on this one, it seems so simple, but takes that much time. I have been crunching my head since days thinking how I could improve this line... Can you give me a suggestion how to improve this part, or is it already at its best?

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  • NEED your opinion on .net Profile class VS session vars

    - by Ted
    To save trips to sql db in my older apps, I store *dozens of data points about the current user in an array and then store the array in a session. For example, info that might be used repeatedly during user’s session might be stored… Dim a(7) as string a(0) = “FirstName” a(1) = “LastName” a(2) = “Address” a(3) = “Address2” a(4) = “City” a(5) = “State” a(6) = “Zip” session.add(“s_a”, a) *Some apps have an array 100 in size. That is something I learned in my asp classic days. Referencing the correct index can be laborsome and I find it difficult to go back and add another data point in the array grouped with like data. For example, suppose I need to add Middle Initial to the array as a design alteration. Unless I redo the whole index mapping, I have to stick Middle Initial in the next open slot, which might be in the 50s. NOW, I am considering doing something easier to reference each time (eliminating the need to know the index of the value wanted). So I am looking to do this… session.add(“Firstname”, “FirstName”) session.add(“Lastname”, “LastName”) session.add(“Address”, “Address”) etc. BUT, before I do this, I would like some guidance. I am afraid this might be less efficient, even though easier to use. I don’t know if a new session object is created for each data point or if there is only one session object, and I am adding a name/value pair to that object? If I am adding a name/value pair to a single object, that seems like a good idea. Does anyone know? Or is there a more preferred way? Built-in Profile class? Re: Profile class I have an internal debate about scope. It seems that the .net Profile class is good for storing app-SPECIFIC user settings (i.e. style theme, object display properties, user role, etc.) The examples I give are information whose values are selected/edited by the user to customize the application experience. This information is not typically stored/edited elsewhere in the app db. But when you have data that 1) is stored already in the app db and 2) can be altered by other users (in this case: company reps may update client's status, address, etc.), then the persistence of the Profile data may be an issue. In this case, the Profile would need to be reset at the beginning and dropped like a session.abandon at the end of each user's session to prevent reloading info that had since been edited by someone. I believe this is possible, but not sure Currently, I use the session array to store both scopes, app-specific and user-specific data. If my session plan is good, I think I will create a class to set/get values from the session also. I appreciate your thoughts. I would like to know how others have handled this type of situation. Thanks.

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