Search Results

Search found 9727 results on 390 pages for 'general concepts'.

Page 359/390 | < Previous Page | 355 356 357 358 359 360 361 362 363 364 365 366  | Next Page >

  • Nested Transaction issues within custom Windows Service

    - by pdwetz
    I have a custom Windows Service I recently upgraded to use TransactionScope for nested transactions. It worked fine locally on my old dev machine (XP sp3) and on a test server (Server 2003). However, it fails on my new Windows 7 machine as well as on 2008 Server. It was targeting 2.0 framework; I tried targeting 3.5 instead, but it still fails. The strange part is really in how it fails; no exception is thrown. The service itself merely times out. I added tracing code, and it fails when opening the connection for Database lookup #2 below. I also enabled tracing for System.Transactions; it literally cuts out partway while writing the block for the failed connection. We ran a SQL trace, but only the first lookup shows up. I put in code traces, and it gets to the trace the line before the second lookup, but nothing after. I've had the same experience hitting two different SQL servers (both are SQL 2005 running on Server 2003). The connection string is utilizing a SQL account (not Windows integration). All connections are against the same database in this case, but given the nature of the code it is being escalated to MSDTC. Here's the basic code structure: TransactionOptions options = new TransactionOptions(); options.IsolationLevel = System.Transactions.IsolationLevel.ReadCommitted; using (TransactionScope scope = new TransactionScope(TransactionScopeOption.RequiresNew, options)) { // Database lookup #1 TransactionOptions options = new TransactionOptions(); options.IsolationLevel = Transaction.Current != null ? Transaction.Current.IsolationLevel : System.Transactions.IsolationLevel.ReadCommitted; using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, options)) { // Database lookup #2; fails on connection.Open() // Database save (never reached) scope.Complete();<br/> } scope.Complete();<br/> } My local firewall is disabled. The service normally runs using Network Service, but I also tried my user account (same results). The short of it is that I use the same general technique widely in my web applications and haven't had any issues. I pulled out the code and ran it fine within a local Windows Form application. If anyone has any additional debugging ideas (or, even better, solutions) I'd love to hear them.

    Read the article

  • Facebook Like not Pulling Title

    - by matthewb
    I am having some issues with the new facebook like button. It shows up fine, however for some reason it's not pulling the title of the page. I have the and I am using og:title, all are filled in, when I view the source of the iframe created on the load of he button, the in there is blank. I am also trying to put the tweetmeme and that's seeing that title and not the meta, or the normal page title. What am I doing wrong? <html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://opengraphprotocol.org/schema/" xmlns:fb="http://developers.facebook.com/schema/"> <fb:like href="<?=$url?>" layout="button_count" show_faces="false" width="100" font="arial"></fb:like> UPDATE: Complete Head <head> <title>Ladder 15 Gets A New Menu!</title> <meta content="Growing up can be hard to do, especially in the Mad River family. But Ladder 15 has come into its own over the winter.&nbsp; With some new cocktails, wine selection, a hefty new beer list and veteran Chef David Ansill in the kitchen, you can check your fist pump at" name="Description"> <meta content="" name="Keywords"> <meta content="cities2night inc." name="author"> <meta content="Cities2Night 2010" name="copyright"> <meta content="en-us" name="language"> <meta content="General" name="rating"> <meta content="index,follow" name="robots"> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> <meta content="Ladder 15 gets a new menu!" name="tweetmeme-title"> <meta content="Ladder 15 gets a new menu!" property="og:title"> <meta content="article" property="og:type"> <meta content="http://philly.cities2night.com/articles/show/listing/11/ladder-15-gets-a-new-menu" property="og:url"> <meta content="http://philly.cities2night.com/public/article_images/11.jpg" property="og:image"> <meta content="c0176da0ec38aaf107c0ef6c8cdeee38" property="fb:app_id"> <meta content="Philly2night.com" property="og:site_name"> <meta content="Growing up can be hard to do, especially in the Mad River family. But Ladder" property="og:description"></head>

    Read the article

  • Throwing cats out of windows

    - by AndrewF
    Imagine you're in a tall building with a cat. The cat can survive a fall out of a low story window, but will die if thrown from a high floor. How can you figure out the longest drop that the cat can survive, using the least number of attempts? Obviously, if you only have one cat, then you can only search linearly. First throw the cat from the first floor. If it survives, throw it from the second. Eventually, after being thrown from floor f, the cat will die. You then know that floor f-1 was the maximal safe floor. But what if you have more than one cat? You can now try some sort of logarithmic search. Let's say that the build has 100 floors and you have two identical cats. If you throw the first cat out of the 50th floor and it dies, then you only have to search 50 floors linearly. You can do even better if you choose a lower floor for your first attempt. Let's say that you choose to tackle the problem 20 floors at a time and that the first fatal floor is #50. In that case, your first cat will survive flights from floors 20 and 40 before dying from floor 60. You just have to check floors 41 through 49 individually. That's a total of 12 attempts, which is much better than the 50 you would need had you attempted to use binary elimination. In general, what's the best strategy and it's worst-case complexity for an n-storied building with 2 cats? What about for n floors and m cats? Assume that all cats are equivalent: they will all survive or die from a fall from a given window. Also, every attempt is independent: if a cat survives a fall, it is completely unharmed. This isn't homework, although I may have solved it for school assignment once. It's just a whimsical problem that popped into my head today and I don't remember the solution. Bonus points if anyone knows the name of this problem or of the solution algorithm.

    Read the article

  • Separate specific #ifdef branches

    - by detly
    In short: I want to generate two different source trees from the current one, based only on one preprocessor macro being defined and another being undefined, with no other changes to the source. If you are interested, here is my story... In the beginning, my code was clean. Then we made a new product, and yea, it was better. But the code saw only the same peripheral devices, so we could keep the same code. Well, almost. There was one little condition that needed to be changed, so I added: #if defined(PRODUCT_A) condition = checkCat(); #elif defined(PRODUCT_B) condition = checkCat() && checkHat(); #endif ...to one and only one source file. In the general all-source-files-include-this header file, I had: #if !(defined(PRODUCT_A)||defined(PRODUCT_B)) #error "Don't make me replace you with a small shell script. RTFM." #endif ...so that people couldn't compile it unless they explicitly defined a product type. All was well. Oh... except that modifications were made, components changed, and since the new hardware worked better we could significantly re-write the control systems. Now when I look upon the face of the code, there are more than 60 separate areas delineated by either: #ifdef PRODUCT_A ... #else ... #endif ...or the same, but for PRODUCT_B. Or even: #if defined(PRODUCT_A) ... #elif defined(PRODUCT_B) ... #endif And of course, sometimes sanity took a longer holiday and: #ifdef PRODUCT_A ... #endif #ifdef PRODUCT_B ... #endif These conditions wrap anywhere from one to two hundred lines (you'd think that the last one could be done by switching header files, but the function names need to be the same). This is insane. I would be better off maintaining two separate product-based branches in the source repo and porting any common changes. I realise this now. Is there something that can generate the two different source trees I need, based only on PRODUCT_A being defined and PRODUCT_B being undefined (and vice-versa), without touching anything else (ie. no header inclusion, no macro expansion, etc)?

    Read the article

  • Copy all childNodes to an other element. In javascript native way.

    - by kroko
    Hello I have to change "unknown" contents of XML. The structure and content itself is valid. Original <blabla foo="bar"> <aa>asas</aa> <ff> <cc> <dd /> </cc> </ff> <gg attr2="2"> </gg> ... ... </blabla> becomes <blabla foo="bar"> <magic> <aa>asas</aa> <ff> <cc> <dd /> </cc> </ff> <gg attr2="2"> </gg> ... ... </magic> </blabla> thus, adding a child straight under document root node (document.documentElement) and "pushing" the "original" children under that. Here it has to be done in plain javascript (ecmascript). The idea now is to // Get the root node RootNode = mymagicdoc.documentElement; // Create new magic element (that will contain contents of original root node) var magicContainer = mymagicdoc.createElement("magic"); // Copy all root node children (and their sub tree - deep copy) to magic node /* ????? here RootNodeClone = RootNode.cloneNode(true); RootNodeClone.childNodes...... */ // Remove all children from root node while(RootNode.hasChildNodes()) RootNode.removeChild(RootNode.firstChild); // Now when root node is empty add the magicContainer // node in it that contains all the children of original root node RootNode.appendChild(magicContainer); How to do that /* */ step? Or maybe someone has a much better solution in general for achieving the desirable result? Thank you in advance!

    Read the article

  • Remove links with Javascript

    - by Arlen Beiler
    How do I remove links from a webpage with Javascript. I am using Google Chrome. The code I tried is: function removehyperlinks() { try { alert(document.anchors.length); alert(document.getElementsByTagName('a')); for(i=0;i=document.anchors.length;i++) { var a = document.anchors[i]; a.outerHTML = a.innerHTML; var b = document.getElementsByTagName('a'); b[i].outerHTML = b[i].innerHTML; } } catch(e) { alert (e);} alert('done'); } Of course, this is test code, which is why I have the alerts and 2 things trying at the same time. The first alert returns "0" the second [Object NodeList] and the third returns "done". My html body looks like this: <body onload="removehyperlinks()"> <ol style="text-align:left;" class="messagelist"> <li class="accesscode"><a href="#">General information, Updates, &amp; Meetings<span class="extnumber">141133#</span></a> <ol> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li><a href="#">...</a></li> <li start="77"><a href="#"">...</a></li> <li start="88"><a href="#">...</a></li> <li start="99"><a href="#">...</a></li> </ol> </li> </ol> </body>

    Read the article

  • Twitter Bootstrap: How to use containers and rows

    - by StackOverflowNewbie
    Assume the following layout: I'm trying to learn how to use Twitter's Bootstrap. What should the general structure of the framework's markup be? Is it this: <div class="container-fluid"> <div class="row-fluid"> <div class="span12"> // Outside link mark up here </div> </div> </div> <div class="container-fluid"> <div class="row-fluid"> <div class="span1"> // Logo mark up here </div> <div class="span4"> // Main nav mark up here </div> <div class="span3 offset4"> // User nav mark up here </div> </div> </div> <div class="container-fluid"> <div class="row-fluid"> <div class="span3"> // Left sidebar mark up here </div> <div class="span6"> <div class="span6"> // Breadcrumb mark up here </div> <div class="span6"> // Main content mark up here </div> </div> <div class="span3"> // Right sidebar mark up here </div> </div> </div> <div class="container-fluid"> <div class="row-fluid"> <div class="span3 offset9"> // Footer link mark up here </div> </div> </div>

    Read the article

  • Gradual memory leak in loop over contents of QTMovie

    - by Benji XVI
    I have a simple foundation tool that exports every frame of a movie as a .tiff file. Here is the relevant code: NSString* movieLoc = [NSString stringWithCString:argv[1]]; QTMovie *sourceMovie = [QTMovie movieWithFile:movieLoc error:nil]; int i=0; while (QTTimeCompare([sourceMovie currentTime], [sourceMovie duration]) != NSOrderedSame) { // save image of movie to disk NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSString *filePath = [NSString stringWithFormat:@"/somelocation_%d.tiff", i++]; NSData *currentImageData = [[sourceMovie currentFrameImage] TIFFRepresentation]; [currentImageData writeToFile:filePath atomically:NO]; NSLog(@"%@", filePath); [sourceMovie stepForward]; [arp release]; } [pool drain]; return 0; As you can see, in order to prevent very large memory buildups with the various transparently-autoreleased variables in the loop, we create, and flush, an autoreleasepool with every run through the loop. However, over the course of stepping through a movie, the amount of memory used by the program still gradually increases. Instruments is not detecting any memory leaks per se, but the object trace shows certain General Data blocks to be increasing in size. [Edited out reference to slowdown as it doesn't seem to be as much of a problem as I thought.] Edit: let's knock out some parts of the code inside the loop & see what we find out... Test 1 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSString *filePath = [NSString stringWithFormat:@"/somelocation_%d.tiff", i++]; NSLog(@"%@", filePath); [sourceMovie stepForward]; [arp release]; } Here we simply loop over the whole movie, creating the filename and logging it. Memory characteristics: remains at 15MB usage for the duration. Test 2 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSImage *image = [sourceMovie currentFrameImage]; [sourceMovie stepForward]; [arp release]; } Here we add back in the creation of the NSImage from the current frame. Memory characteristics: gradually increasing memory usage. RSIZE is at 60MB by frame 200; 75MB by f300. Test 3 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSImage *image = [sourceMovie currentFrameImage]; NSData *imageData = [image TIFFRepresentation]; [sourceMovie stepForward]; [arp release]; } We've added back in the creation of an NSData object from the NSImage. Memory characteristics: Memory usage is again increasing: 62MB at f200; 75MB at f300. In other words, largely identical. It looks like a memory leak in the underlying system QTMovie uses to do currentFrameImage, to me.

    Read the article

  • Multi-threaded Pooled Allocators

    - by Darren Engwirda
    I'm having some issues using pooled memory allocators for std::list objects in a multi-threaded application. The part of the code I'm concerned with runs each thread function in isolation (i.e. there is no communication or synchronization between threads) and therefore I'd like to setup separate memory pools for each thread, where each pool is not thread-safe (and hence fast). I've tried using a shared thread-safe singleton memory pool and found the performance to be poor, as expected. This is a heavily simplified version of the type of thing I'm trying to do. A lot has been included in a pseudo-code kind of way, sorry if it's confusing. /* The thread functor - one instance of MAKE_QUADTREE created for each thread */ class make_quadtree { private: /* A non-thread-safe memory pool for int linked list items, let's say that it's * something along the lines of BOOST::OBJECT_POOL */ pooled_allocator<int> item_pool; /* The problem! - a local class that would be constructed within each std::list as the * allocator but really just delegates to ITEM_POOL */ class local_alloc { public : //!! I understand that I can't access ITEM_POOL from within a nested class like //!! this, that's really my question - can I get something along these lines to //!! work?? pointer allocate (size_t n) { return ( item_pool.allocate(n) ); } }; public : make_quadtree (): item_pool() // only construct 1 instance of ITEM_POOL per // MAKE_QUADTREE object { /* The kind of data structures - vectors of linked lists * The idea is that all of the linked lists should share a local pooled allocator */ std::vector<std::list<int, local_alloc>> lists; /* The actual operations - too complicated to show, but in general: * * - The vector LISTS is grown as a quadtree is built, it's size is the number of * quadtree "boxes" * * - Each element of LISTS (each linked list) represents the ID's of items * contained within each quadtree box (say they're xy points), as the quadtree * is grown a lot of ID pop/push-ing between lists occurs, hence the memory pool * is important for performance */ } }; So really my problem is that I'd like to have one memory pool instance per thread functor instance, but within each thread functor share the pool between multiple std::list objects.

    Read the article

  • When is ¦ not equal to ¦?

    - by Trey Jackson
    Background. I'm working with netlists, and in general, people specify different hierarchies by using /. However, it's not illegal to actually use a / as a part of an instance name. For example, X1/X2/X3/X4 might refer to instance X4 inside another instance named X1/X2/X3. Or it might refer an instance named X3/X4 inside an instance named X2 inside an instance named X1. Got it? There's really no "regular" character that cannot be used as a part of an instance name, so you resort to a non-printable one, or ... perhaps one outside of the standard 0..127 ASCII chars. I thought I'd try (decimal) 166, because for me it shows up as the pipe: ¦. So... I've got some C++ code which constructs the path name using ¦ as the hierarchical separator, so the path above looks like X1¦X2/X3¦X4. Now the GUI is written in Tcl/Tk, and to properly translate this into human readable terms I need to do something like the following: set path [getPathFromC++] ;# returns X1¦X2/X3¦X4 set humanreadable [join [split $path ¦] /] Basically, replace the ¦ with / (I could also accomplish this with [string map]). Now, the problem is, the ¦ in the string I get from C++ doesn't match the ¦ I can create in Tcl. i.e. This fails: set path [getPathFromC++] ;# returns X1¦X2/X3¦X4 string match $path [format X1%cX2/X3%cX4 166 166] Visually, the two strings look identical, but string match fails. I even tried using scan to see if I'd mixed up the bit values. But set path [getPathFromC++] ;# returns X1¦X2/X3¦X4 set path2 [format X1%cX2/X3%cX4 166 166] for {set i 0} {$i < [string length $path]} {incr i} { set p [string range $path $i $i] set p2 [string range $path2 $i $i] scan %c $p c scan %c $p2 c2 puts [list $p $c :::: $p2 $c2 equal? [string equal $c $c2]] } Produces output which looks like everything should match, except the [string equal] fails for the ¦ characters with a print line: ¦ 166 :::: ¦ 166 equal? 0 For what it's worth, the character in C++ is defined as: const char SEPARATOR = 166; Any ideas why a character outside the regular ASCII range would fail like this? When I changed the separator to (decimal) 28 (^\), things worked fine. I just don't want to get bit by a similar problem on a different platform. (I'm currently using Redhat Linux).

    Read the article

  • A NSMutableArray is destroying my life!

    - by camilo
    EDITED to show the relevant part of the code Hi. There's a strange problem with an NSMutableArray which I'm just not understanding... Explaining: I have a NSMutableArray, defined as a property (nonatomic, retain), synthesized, and initialized with 29 elements. realSectionNames = [[NSMutableArray alloc] initWithCapacity:29]; After the initialization, I can insert elements as I wish and everything seems to be working fine. While I'm running the application, however, if I insert a new element in the array, I can print the array in the function where I inserted the element, and everything seems ok. However, when I select a row in the table, and I need to read that array, my application crashes. In fact, it cannot even print the array anymore. Is there any "magical and logical trick" everybody should know when using a NSMutableArray that a beginner like myself can be missing? Thanks a lot. I declare my array as realSectionNames = [[NSMutableArray alloc] initWithCapacity:29]; I insert objects in my array with [realSectionNames addObject:[category categoryFirstLetter]]; although I know i can also insert it with [realSectionNames insertObject:[category categoryFirstLetter] atIndex:i]; where the "i" is the first non-occupied position. After the insertion, I reload the data of my tableView. Printing the array before or after reloading the data shows it has the desired information. After that, selecting a row at the table makes the application crash. This realSectionNames is used in several UITableViewDelegate functions, but for the case it doesn't matter. What truly matters is that printing the array in the beginning of the didSelectRowAtIndexPath function crashes everything (and of course, doesn't print anything). I'm pretty sure it's in that line, for printing anything he line before works (example): NSLog(@"Anything"); NSLog(@"%@", realSectionNames); gives the output: 2010-03-24 15:16:04.146 myApplicationExperience[3527:207] Anything [Session started at 2010-03-24 15:16:04 +0000.] GNU gdb 6.3.50-20050815 (Apple version gdb-967) (Tue Jul 14 02:11:58 UTC 2009) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-apple-darwin".sharedlibrary apply-load-rules all Attaching to process 3527. Still not understanding what kind of stupidity I've done this time... maybe it's not too late to follow the career of brain surgeon?

    Read the article

  • highlight query string in more than one field using solr search feature

    - by Romi
    i am using solr indexes for showing my search results. to show serch results i am parsing json data received from solr. i am able to highlight a query string in search result but only in a single field. for this i set hl=true and hl.fl="field1". i did it as $.getJSON("http://192.168.1.9:8983/solr/db/select/?wt=json&&start=0&rows=100&q="+lowerCaseQuery+"&hl=true&hl.fl=description,name&hl.usePhraseHighlighter=true&sort=price asc&json.wrf=?", function(result){ var n=result.response.numFound var highlight = new Array(n); $.each(result.highlighting, function(i, hitem){ var match = hitem.text[0].match(/<em>(.*?)<\/em>/); highlight[i]=match[1]; }); $.each(newresult.response.docs, function(i,item){ var word=highlight[item["UID_PK"]]; var result = item.text[0].replace(new RegExp(word,'g'), '<em>' + word + '</em>'); }); for this json object is as : { "responseHeader": { "status": 0, "QTime": 32 }, "response": { "numFound": 21, "start": 0, "docs": [ { "description": "The matte finish waves on this wedding band contrast with the high polish borders. This sharp and elegant design was finely crafted in Japan.", "UID_PK": "8252", }, { "description": "This elegant ring has an Akoya cultured pearl with a band of bezel-set round diamonds making it perfect for her to wear to work or the night out.", "UID_PK": "8142", }, ] }, "highlighting": { "8252": { "description": [ " and <em>elegant</em> design was finely crafted in Japan." ] }, "8142": { "description": [ "This <em>elegant</em> ring has an Akoya cultured pearl with a band of bezel-set round diamonds making" ] }, } } Now if i want to highlight query string in two fields i did as hl=true hl.fl=descrption, name my json is as: { "responseHeader":{ "status":0, "QTime":16 }, "response":{ "numFound":1904, "start":0, "docs":[ { "description":"", "UID_PK":"7780", "name":[ "Diamond bracelet with Milgrain Bezel1" ] }, { "description":"This pendant is sure to win hearts. Round diamonds form a simple and graceful line.", "UID_PK":"8121", "name":[ "Heartline Diamond Pendant" ] }, "highlighting":{ "7780":{ "name":[ "<em>Diamond</em> bracelet with Milgrain Bezel1" ] }, "8121":{ "description":[ "This pendant is sure to win hearts. Round <em>diamonds</em> form a simple and graceful line." ], "name":[ "Heartline <em>Diamond</em> Pendant" ] } } } Now how should i parse it to get the result. suggest me some general technique, so if i want to highlight query in more fields then i could do so. Thanks

    Read the article

  • how to refactor user-permission system?

    - by John
    Sorry for lengthy question. I can't tell if this should be a programming question or a project management question. Any advice will help. I inherited a reasonably large web project (1 year old) from a solo freelancer who architected it then abandoned it. The project was a mess, but I cleaned up what I could, and now the system is more maintainable. I need suggestions on how to extend the user-permission system. As it is now, the database has a t_user table with the column t_user.membership_type. Currently, there are 4 membership types with the following properties: 3 of the membership types are almost functionally the same, except for the different monthly fees each must pay 1 of the membership type is a "fake-user" type which has limited access ( different business logic also applies) With regards to the fake-user type, if you look in the system's business logic files, you will see a lot of hard-coded IF statements that do something like if (fake-user) { // do something } else { // a paid member of type 1,2 or 3 // proceed normally } My client asked me to add 3 more membership types to the system, each of them with unique features to be implemented this month, and substantive "to-be-determined" features next month. My first reaction is that I need to refactor the user-permission system. But it concerns me that I don't have enough information on the "to-be-determined" membership type features for next month. Refactoring the user-permission system will take a substantive amount of time. I don't want to refactor something and throw it out the following month. I get substantive feature requests on a monthly basis that come out of the blue. There is no project road map. I've asked my client to provide me with a roadmap of what they intend to do with the new membership types, but their answer is along the lines of "We just want to do [feature here] this month. We'll think of something new next month." So questions that come to mind are: 1) Is it dangerous for me to refactor the user permission system not knowing what membership type features exist beyond a month from now? 2) Should I refactor the user permission system regardless? Or just continue adding IF statements as needed in all my controller files? Or can you recommend a different approach to user permission systems? Maybe role-based ? 3) Should this project have a road map? For a 1 year old project like mine, how far into the future should this roadmap project? 4) Any general advice on the best way to add 3 new membership types?

    Read the article

  • Design patterns and interview question

    - by user160758
    When I was learning to code, I read up on the design patterns like a good boy. Long after this, I started to actually understand them. Design discussions such as those on this site constantly try to make the rules more and more general, which is good. But there is a line, over which it becomes over-analysis starts to feed off itself and as such I think begins to obfuscate the original point - for example the "What's Alternative to Singleton" post and the links contained therein. http://stackoverflow.com/questions/1300655/whats-alternative-to-singleton I say this having been asked in both interviews I’ve had over the last 2 weeks what a singleton is and what criticisms I have of it. I have used it a few times for items such as user data (simple key-value eg. last file opened by this user) and logging (very common i'm sure). I've never ever used it just to have what is essentially global application data, as this is clearly stupid. In the first interview, I reply that I have no criticisms of it. He seemed disappointed by this but as the job wasn’t really for me, I forgot about it. In the next one, I was asked again and, as I wanted this job, I thought about it on the spot and made some objections, similar to those contained in the post linked to above (I suggested use of a factory or dependency injection instead). He seemed happy with this. But my problem is that I have used the singleton without ever using it in this kind of stupid way, which I had to describe on the spot. Using it for global data and the like isn’t something I did then realised was stupid, or read was stupid so didn’t do, it was just something I knew was stupid from the start. Essentially I’m supposed to be able to think of ways of how to misuse a pattern in the interview? Which class of programmers can best answer this question? The best ones? The medium ones? I'm not sure.... And these were both bright guys. I read more than enough to get better at my job but had never actually bothered to seek out criticisms of the most simple of the design patterns like this one. Do people think such questions are valid and that I ought to know the objections off by heart? Or that it is reasonable to be able to work out what other people who are missing the point would do on the fly? Or do you think I’m at least partially right that the question is too unsubtle and that the questions ought to be better thought out in order to make sure only good candidates can answer. PS. Please don’t think I’m saying that I’m just so clever that I know everything automatically - I’ve learnt the hard way like everyone else. But avoiding global data is hardly revolutionary.

    Read the article

  • approximating log10[x^k0 + k1]

    - by Yale Zhang
    Greetings. I'm trying to approximate the function Log10[x^k0 + k1], where .21 < k0 < 21, 0 < k1 < ~2000, and x is integer < 2^14. k0 & k1 are constant. For practical purposes, you can assume k0 = 2.12, k1 = 2660. The desired accuracy is 5*10^-4 relative error. This function is virtually identical to Log[x], except near 0, where it differs a lot. I already have came up with a SIMD implementation that is ~1.15x faster than a simple lookup table, but would like to improve it if possible, which I think is very hard due to lack of efficient instructions. My SIMD implementation uses 16bit fixed point arithmetic to evaluate a 3rd degree polynomial (I use least squares fit). The polynomial uses different coefficients for different input ranges. There are 8 ranges, and range i spans (64)2^i to (64)2^(i + 1). The rational behind this is the derivatives of Log[x] drop rapidly with x, meaning a polynomial will fit it more accurately since polynomials are an exact fit for functions that have a derivative of 0 beyond a certain order. SIMD table lookups are done very efficiently with a single _mm_shuffle_epi8(). I use SSE's float to int conversion to get the exponent and significand used for the fixed point approximation. I also software pipelined the loop to get ~1.25x speedup, so further code optimizations are probably unlikely. What I'm asking is if there's a more efficient approximation at a higher level? For example: Can this function be decomposed into functions with a limited domain like log2((2^x) * significand) = x + log2(significand) hence eliminating the need to deal with different ranges (table lookups). The main problem I think is adding the k1 term kills all those nice log properties that we know and love, making it not possible. Or is it? Iterative method? don't think so because the Newton method for log[x] is already a complicated expression Exploiting locality of neighboring pixels? - if the range of the 8 inputs fall in the same approximation range, then I can look up a single coefficient, instead of looking up separate coefficients for each element. Thus, I can use this as a fast common case, and use a slower, general code path when it isn't. But for my data, the range needs to be ~2000 before this property hold 70% of the time, which doesn't seem to make this method competitive. Please, give me some opinion, especially if you're an applied mathematician, even if you say it can't be done. Thanks.

    Read the article

  • Looking for an Open Source Project in need of help

    - by hvidgaard
    Hi StackOverflow! I'm a CS student on well on my way to graduate. I have had a difficult time of finding relevant student jobs (they seems to be taken merely hours after the notice gets on the board) , so instead I'm looking for an open source project in need of help. I'm aware that I should choose one that I use, but I'm not aware of any OS-project that I use that needs help. That's why I'm asking you. I don't have any deep experience, but I here are some of my biggest projects so far: BitTorrent-ish client in Python (a subset of BitTorrent) HTTP 1.1 webserver in Java Compiler from a subset of Java to run on JRE Flash-framework project to model an iPad look and feel (not to run actual iPad programs) complete with an API for programs. Complete MySQL database for a booking system, with departure and arrival times, so you could only book valid tickets (with a Java frontend). I know, Java and languages like AS3 and C# feels natural per se, Python, and have done a fair bit of hacking around in C, but I don't feel very comfortable with it. Mostly I'm afraid to make a fuckup because I have such a high degree of control. I would like to think I'm well aware of good software design practices, but in reality what I do is ask myself "would I like to use/maintain this?", and I love to refactor my code because I see optimizations. I love algorithms and to make them run in the best possible time. I don't have any preferred domain to work in, but I wouldn't mind it to be graphics or math heavy. Ideally I'm looking for a project in C++ to learn the in's and out's of it, but I'm well aware that I don't know that language very well. I would like to have a mentor-like figure until I'm confident enough to stand on my own, not one to review all my code (I'm sure someone will to start with anyway), but to ask questions about the project and language in question. I do have a wife and two children, so don't expect me to put in 10+ hours every week. In return I can work on my own, I strive to program modular and maintainable code. Know how to read an API, use Google, StackOverflow and online resources in general. If you have any questions, shoot. I'm looking forward to your suggestions.

    Read the article

  • Change user control appearance based on state

    - by John
    I have a user control that consists of four overlapping items: 2 rectangles, an ellipse and a lable <UserControl x:Class="UserControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="50.1" Height="45.424" Background="Transparent" FontSize="24"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="3.303*" /> <RowDefinition Height="40*" /> <RowDefinition Height="2.121*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="5.344*" /> <ColumnDefinition Width="40.075*" /> <ColumnDefinition Width="4.663*" /> </Grid.ColumnDefinitions> <Rectangle Name="Rectangle1" RadiusX="5" RadiusY="5" Fill="DarkGray" Grid.ColumnSpan="3" Grid.RowSpan="3" /> <Ellipse Name="ellipse1" Fill="{Binding State}" Margin="0.016,0.001,4.663,0" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2" Stroke="Black" IsEnabled="True" Panel.ZIndex="2" /> <Label Name="lblNumber" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" Foreground="White" FontWeight="Bold" FontSize="24" Grid.Column="1" Grid.Row="1" Padding="0" Panel.ZIndex="3">9</Label> <Rectangle Grid.Column="1" Grid.Row="1" Margin="0.091,0,4.663,0" Fill="Blue" Name="rectangle2" Stroke="Black" Grid.ColumnSpan="2" Panel.ZIndex="1" /> </Grid> Here is my business object that I want to control the state of my user control: Imports System.Data Imports System.ComponentModel Public Class BusinessObject Implements INotifyPropertyChanged 'Public logger As log4net.ILog Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged Private _state As States Public Enum States State1 State2 State3 End Enum Public Property State() As States Get Return _state End Get Set(ByVal value As States) If (value <> _state) Then _state = value RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("State")) End If End Set End Property Protected Sub OnPropertyChanged(ByVal name As String) RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(name)) End Sub I want to be able to change the state of a business object in the code behind and have that change the colors of multiple shapes in my usercontrol. I'm not sure about how to do the binding. I set the datacontext of the user control in the code behind but not sure if that's right. I'm new to WPF and programming in general and I'm stuck on where to go from here. Any recommendations would be greatly appreciated!!

    Read the article

  • mysql timeout - c/C++

    - by user1262876
    Guys i'm facing a problem with this code, the problem is the timeout by timeout i mean the time it takes the program to tell me if the server is connected or not. If i use my localhost i get the answer fast, but when i connect to outside my localhost it takes 50sc - 1.5 min to response and the program frezz until it done. HOw can i fix the frezzing, or make my own timeout, like if still waiting after 50sc, tell me connection failed and stop? please use codes as help, becouse i would understand it better, thanks for any help i get PS: USING MAC #include "mysql.h" #include <stdio.h> #include <stdlib.h> // Other Linker Flags: -lmysqlclient -lm -lz // just going to input the general details and not the port numbers struct connection_details { char *server; char *user; char *password; char *database; }; MYSQL* mysql_connection_setup(struct connection_details mysql_details) { // first of all create a mysql instance and initialize the variables within MYSQL *connection = mysql_init(NULL); // connect to the database with the details attached. if (!mysql_real_connect(connection,mysql_details.server, mysql_details.user, mysql_details.password, mysql_details.database, 0, NULL, 0)) { printf("Conection error : %s\n", mysql_error(connection)); exit(1); } return connection; } MYSQL_RES* mysql_perform_query(MYSQL *connection, char *sql_query) { // send the query to the database if (mysql_query(connection, sql_query)) { printf("MySQL query error : %s\n", mysql_error(connection)); exit(1); } return mysql_use_result(connection); } int main() { MYSQL *conn; // the connection MYSQL_RES *res; // the results MYSQL_ROW row; // the results row (line by line) struct connection_details mysqlD; mysqlD.server = (char*)"Localhost"; // where the mysql database is mysqlD.user = (char*)"root"; // the root user of mysql mysqlD.password = (char*)"123456"; // the password of the root user in mysql mysqlD.database = (char*)"test"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); // assign the results return to the MYSQL_RES pointer res = mysql_perform_query(conn, (char*) "SELECT * FROM me"); printf("MySQL Tables in mysql database:\n"); while ((row = mysql_fetch_row(res)) !=NULL) printf("%s - %s\n", row[0], row[1], row[2]); // <-- Rows /* clean up the database result set */ mysql_free_result(res); /* clean up the database link */ mysql_close(conn); return 0; }

    Read the article

  • How to rectify this program?

    - by user1430719
    This is a program to display a pie chart. I also have a button. But the program I have written, creates two separate frames and one frame is for the pie chart and the other is for the button. How do I put both button and pie chart on the same frame?? Can you please rectify my program. import java.awt.*; import org.jfree.chart.*; import org.jfree.chart.title.*; import org.jfree.data.general.DefaultPieDataset; import org.jfree.ui.*; import java.io.*; import javax.swing.*; import java.awt.event.*; import javax.swing.filechooser.*; public class Pie{ public static void getFile(File f) { System.out.println("File is: "+f.getName()); } public static void main(String[] args) { JPanel panel=new JPanel(); panel.setLayout(null); JButton b=new JButton("Open File"); b.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { JFileChooser chooser=new JFileChooser(); int ret = chooser.showDialog(null, "Open file"); if (ret == JFileChooser.APPROVE_OPTION) { File file = chooser.getSelectedFile(); getFile(file); } } } ); b.setBounds(50,40,100,35); panel.add(b); DefaultPieDataset pieDataset = new DefaultPieDataset(); pieDataset.setValue("A", new Integer(10)); pieDataset.setValue("B", new Integer(20)); pieDataset.setValue("C", new Integer(30)); pieDataset.setValue("D", new Integer(10)); pieDataset.setValue("E", new Integer(20)); pieDataset.setValue("F", new Integer(10)); JFreeChart chart = ChartFactory.createPieChart("Pie Chart using JFreeChart", pieDataset, true,true,true); ChartFrame frame1=new ChartFrame("Pie Chart",chart); frame1.add(panel); frame1.setVisible(true); frame1.setSize(600,600); } }

    Read the article

  • iPhone Debugger Message -- Weird

    - by Bill Shiff
    Hello, I have an iPhone app that I've been working on and have recently upgraded my version of XCode. Since the upgrade, I can build and debug in the iPhone Simulator just fine, but when I try to debug on an attached device I get the following messages: From Xcode4: GNU gdb 6.3.50-20050815 (Apple version gdb-1510) (Fri Oct 22 04:12:10 UTC 2010) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "--host=i386-apple-darwin --target=arm-apple-darwin".tty /dev/ttys001 sharedlibrary apply-load-rules all warning: Unable to read symbols from "dyld" (prefix __dyld_) (not yet mapped into memory). warning: Unable to read symbols for (null)/Library/Frameworks/MessageUI.framework/MessageUI (file not found). warning: Unable to read symbols from "MessageUI" (not yet mapped into memory). warning: Unable to read symbols for (null)/Library/Frameworks/MapKit.framework/MapKit (file not found). warning: Unable to read symbols from "MapKit" (not yet mapped into memory). warning: Unable to read symbols from "Foundation" (not yet mapped into memory). warning: Unable to read symbols for (null)/Library/Frameworks/UIKit.framework/UIKit (file not found). warning: Unable to read symbols from "UIKit" (not yet mapped into memory). warning: Unable to read symbols for (null)/Library/Frameworks/CoreGraphics.framework/CoreGraphics (file not found). warning: Unable to read symbols from "CoreGraphics" (not yet mapped into memory). warning: Unable to read symbols from "CoreData" (not yet mapped into memory). warning: Unable to read symbols from "QuartzCore" (not yet mapped into memory). warning: Unable to read symbols from "libgcc_s.1.dylib" (not yet mapped into memory). warning: Unable to read symbols from "libSystem.B.dylib" (not yet mapped into memory). warning: Unable to read symbols from "libobjc.A.dylib" (not yet mapped into memory). warning: Unable to read symbols from "CoreFoundation" (not yet mapped into memory). target remote-mobile /tmp/.XcodeGDBRemote-3836-28 Switching to remote-macosx protocol mem 0x1000 0x3fffffff cache mem 0x40000000 0xffffffff none mem 0x00000000 0x0fff none [Switching to thread 11523] [Switching to thread 11523] gdb stack crawl at point of internal error: 0 gdb-arm-apple-darwin 0x0013216e internal_vproblem + 316

    Read the article

  • Converting C source to C++

    - by Barry Kelly
    How would you go about converting a reasonably large (300K), fairly mature C codebase to C++? The kind of C I have in mind is split into files roughly corresponding to modules (i.e. less granular than a typical OO class-based decomposition), using internal linkage in lieu private functions and data, and external linkage for public functions and data. Global variables are used extensively for communication between the modules. There is a very extensive integration test suite available, but no unit (i.e. module) level tests. I have in mind a general strategy: Compile everything in C++'s C subset and get that working. Convert modules into huge classes, so that all the cross-references are scoped by a class name, but leaving all functions and data as static members, and get that working. Convert huge classes into instances with appropriate constructors and initialized cross-references; replace static member accesses with indirect accesses as appropriate; and get that working. Now, approach the project as an ill-factored OO application, and write unit tests where dependencies are tractable, and decompose into separate classes where they are not; the goal here would be to move from one working program to another at each transformation. Obviously, this would be quite a bit of work. Are there any case studies / war stories out there on this kind of translation? Alternative strategies? Other useful advice? Note 1: the program is a compiler, and probably millions of other programs rely on its behaviour not changing, so wholesale rewriting is pretty much not an option. Note 2: the source is nearly 20 years old, and has perhaps 30% code churn (lines modified + added / previous total lines) per year. It is heavily maintained and extended, in other words. Thus, one of the goals would be to increase mantainability. [For the sake of the question, assume that translation into C++ is mandatory, and that leaving it in C is not an option. The point of adding this condition is to weed out the "leave it in C" answers.]

    Read the article

  • How do I add a filter button to this pagination?

    - by ClarkSKent
    Hey, I want to add a button(link), that when clicked will filter the pagination results. I'm new to php (and programming in general) and would like to add a button like 'Automotive' and when clicked it updates the 2 mysql queries in my pagination script, seen here: As you can see, the category automotive is hardcoded in, I want it to be dynamic, so when a link is clicked it places whatever the id or class is in the category part of the query. 1: $record_count = mysql_num_rows(mysql_query("SELECT * FROM explore WHERE category='automotive'")); 2: $get = mysql_query("SELECT * FROM explore WHERE category='automotive' LIMIT $start, $per_page"); This is the entire current php pagination script that I am using: <?php //connecting to the database $error = "Could not connect to the database"; mysql_connect('localhost','root','root') or die($error); mysql_select_db('ajax_demo') or die($error); //max displayed per page $per_page = 2; //get start variable $start = $_GET['start']; //count records $record_count = mysql_num_rows(mysql_query("SELECT * FROM explore WHERE category='automotive'")); //count max pages $max_pages = $record_count / $per_page; //may come out as decimal if (!$start) $start = 0; //display data $get = mysql_query("SELECT * FROM explore WHERE category='automotive' LIMIT $start, $per_page"); while ($row = mysql_fetch_assoc($get)) { // get data $name = $row['id']; $age = $row['site_name']; echo $name." (".$age.")<br />"; } //setup prev and next variables $prev = $start - $per_page; $next = $start + $per_page; //show prev button if (!($start<=0)) echo "<a href='pagi_test.php?start=$prev'>Prev</a> "; //show page numbers //set variable for first page $i=1; for ($x=0;$x<$record_count;$x=$x+$per_page) { if ($start!=$x) echo " <a href='pagi_test.php?start=$x'>$i</a> "; else echo " <a href='pagi_test.php?start=$x'><b>$i</b></a> "; $i++; } //show next button if (!($start>=$record_count-$per_page)) echo " <a href='pagi_test.php?start=$next'>Next</a>"; ?>

    Read the article

  • Template function as a template argument

    - by Kos
    I've just got confused how to implement something in a generic way in C++. It's a bit convoluted, so let me explain step by step. Consider such code: void a(int) { // do something } void b(int) { // something else } void function1() { a(123); a(456); } void function2() { b(123); b(456); } void test() { function1(); function2(); } It's easily noticable that function1 and function2 do the same, with the only different part being the internal function. Therefore, I want to make function generic to avoid code redundancy. I can do it using function pointers or templates. Let me choose the latter for now. My thinking is that it's better since the compiler will surely be able to inline the functions - am I correct? Can compilers still inline the calls if they are made via function pointers? This is a side-question. OK, back to the original point... A solution with templates: void a(int) { // do something } void b(int) { // something else } template<void (*param)(int) > void function() { param(123); param(456); } void test() { function<a>(); function<b>(); } All OK. But I'm running into a problem: Can I still do that if a and b are generics themselves? template<typename T> void a(T t) { // do something } template<typename T> void b(T t) { // something else } template< ...param... > // ??? void function() { param<SomeType>(someobj); param<AnotherType>(someotherobj); } void test() { function<a>(); function<b>(); } I know that a template parameter can be one of: a type, a template type, a value of a type. None of those seems to cover my situation. My main question is hence: How do I solve that, i.e. define function() in the last example? (Yes, function pointers seem to be a workaround in this exact case - provided they can also be inlined - but I'm looking for a general solution for this class of problems).

    Read the article

  • SQL Server architecture guidance

    - by Liam
    Hi, We are designing a new version of our existing product on a new schema. Its an internal web application with possibly 100 concurrent users (max)This will run on a SQL Server 2008 database. On of the discussion items recently is whether we should have a single database of split the database for performance reasons across 2 separate databases. The database could grow anywhere from 50-100GB over 5 years. We are Developers and not DBAs so it would be nice to get some general guidance. [I know the answer is not simple as it depends on the schema, archiving policy, amount of data etc. ] Option 1 Single Main Database [This is my preferred option]. The plan would be to have all the tables in a single database and possibly to use file groups and partitioning to separate the data if required across multiple disks. [Use schema if appropriate]. This should deal with the performance concerns One of the comments wrt this was that the a single server instance would still be processing this data so there would still be a processing bottle neck. For reporting we could have a separate reporting DB but this is still being discussed. Option 2 Split the database into 2 separate databases DB1 - Customers, Accounts, Customer resources etc DB2 - This would contain the bulk of the data [i.e. Vehicle tracking data, financial transaction tables etc]. These tables would typically contain a lot of data. [It could reside on a separate server if required] This plan would involve keeping the main data in a smaller database [DB1] and retaining the [mainly] read only transaction type data in a separate DB [DB2]. The UI would mainly read from DB1 and thus be more responsive. [I'm aware that this option makes it harder for Referential Integrity to be enforced.] Points for consideration As we are at the design stage we can at least make proper use of indexes to deal performance issues so thats why option 1 to me is attractive and its more of a standard approach. For both options we are considering implementing an archiving database. Apologies for the long Question. In summary the question is 1 DB or 2? Thanks in advance, Liam

    Read the article

  • Is order of parameters for database Command object really important?

    - by nawfal
    I was debugging a database operation code and I found that proper UPDATE was never happening though the code never failed as such. This is the code: condb.Open(); OleDbCommand dbcom = new OleDbCommand("UPDATE Word SET word=?,sentence=?,mp3=? WHERE id=? AND exercise_id=?", condb); dbcom.Parameters.AddWithValue("id", wd.ID); dbcom.Parameters.AddWithValue("exercise_id", wd.ExID); dbcom.Parameters.AddWithValue("word", wd.Name); dbcom.Parameters.AddWithValue("sentence", wd.Sentence); dbcom.Parameters.AddWithValue("mp3", wd.Mp3); But after some tweaking this worked: condb.Open(); OleDbCommand dbcom = new OleDbCommand("UPDATE Word SET word=?,sentence=?,mp3=? WHERE id=? AND exercise_id=?", condb); dbcom.Parameters.AddWithValue("word", wd.Name); dbcom.Parameters.AddWithValue("sentence", wd.Sentence); dbcom.Parameters.AddWithValue("mp3", wd.Mp3); dbcom.Parameters.AddWithValue("id", wd.ID); dbcom.Parameters.AddWithValue("exercise_id", wd.ExID); Why is it so important that the parameters in WHERE clause has to be given the last in case of OleDb connection? Having worked with MySQL previously, I could (and usually do) write parameters of WHERE clause first because that's more logical to me. Is parameter order important when querying database in general? Some performance concern or something? Is there a specific order to be maintained in case of other databases like DB2, Sqlite etc? Update: I got rid of ? and included proper names with and without @. The order is really important. In both cases only when WHERE clause parameters was mentioned last, actual update happened. To make matter worse, in complex queries, its hard to know ourselves which order is Access expecting, and in all situations where order is changed, the query doesnt do its intended duty with no warning/error!!

    Read the article

< Previous Page | 355 356 357 358 359 360 361 362 363 364 365 366  | Next Page >