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  • Has anyone used ever Mangoslick from themeforest?

    - by bonesnatch
    I was assigned to integrate MangoSlick theme to our current admin panel, Its a jQuery, Slick(?) and Responsive template. First, let me explain how the API goes In the documentation, it only says this is the only way data-[options]=[value] Example: If I wanna make a progress bar I can use this format <div class="progress"> <div class="bar" data-title="[title]" data-value="[value]" data-max="[max]" data-format="[format string]"></div> </div> so filling-in values <div class="progress"> <div class="bar" data-title="Space" data-value="1285" data-max="5120" data-format="0,0 MB"></div> </div> I will have this as output Now, the main question is when I use jQuery attr() to change the attribute values for data-title, data-max, data-value and data-format. Why is it not working? <script> var jq = $.noConflict(); jq(document).ready(function(){ jq('#bokz').attr("data-title", "No Space"); }); </script> Using the script above and inspect element in chrome the values are changed but not in the progressbar Some of you may have some ideas on this? Any help/suggestion would be very much appreciated.

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  • What is the worst gotcha in WPF?

    - by David
    Hi, I've started to make myself a list of "WPF gotchas": things that bug me and that I had to write down to remember because I fall for them every time.... Now, I'm pretty sure you all stumbled upon similar situations at one point, and I would like you to share your experience on the subject: What is the gotcha that gets you all the time? the one you find the most annoying? (I have a few issues that seem to be without explanation, maybe your submissions will explain them) Here are a few of my "personnal" gotchas (randomly presented): For a MouseEvent to be fired even when the click is on the "transparent" background of a control (e.g. a label) and not just on the content (the Text in this case), the control's Background has to be set to "Brushes.Transparent" and not just "null" (default value for a label) A WPF DataGridCell's DataContext is the RowView to whom the cell belong, not the CellView When inside a ScrollViewer, a Scrollbar is managed by the scrollviewer itself (i.e. setting properties such as ScrollBar.Value is without effect) Key.F10 is not fired when you press "F10", instead you get Key.System and you have to go look for e.SystemKey to get the Key.F10 ... and now you're on.

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  • Mongodb, linq driver. How to construct Contains with variable or statements

    - by Syska
    I'm using the LINQ Driver for C#, works great. Sorting a lot of properties but heres a problem I can't solve, its probebly simple. var identifierList = new []{"10", "20", "30"}; var newList = list.Where(x => identifierList.Contains(x.Identifier)); This is NOT supported ... So I could do something like: var newList = list.Where(x => x.Identifier == "10" || x.Identifier == "20" || x.Identifier == "30"); But since the list is variable ... how do I construct the above? Or are there even better alternatives? The list is of type IQueryable<MyCustomClass> For information ... this is used as a filter of alot of properties. In SQL I could have a parent - child relationship. But as I can't as the parent for the main ID I need to take all the ID's out and then construct it like this. Hopes this makes sense. If needed I will explain more.

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  • Can I automate a loop query based on category with the page's title?

    - by jordaninternets
    To explain further, I need to get a page to display posts from a specific category. I want to automate this process so I don't have to make a template for each category. How would I do that? (keep in mind the person I'm building this is for has no coding experience.) The only way I could think off from the top of my head is to use the title or slug. So if the category is named the same thing as the slug, could I filter by category using the slug? Maybe this isn't the best way... what should I do? This is what I came up with, but it doesn't work, I'm sure due to improper use on may part, but I've been pouring over the WP codex and Google with no avail to tell me my problem. <?php $paged = (get_query_var('paged')) ? get_query_var('paged') : 1; $args= array( 'orderby' => 'date', 'order' => 'ASC', 'paged' => $paged, 'category_name' => echo the_title('\'','\'',) ); query_posts($args); ?>

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  • MySQL COUNT() total posts within a specific criteria?

    - by newbtophp
    Hey, I've been losing my hair trying to figure out what I'm doing wrong, let me explain abit about my MySQL structure (so you get a better understanding) before I go straight to the question. I have a simple PHP forum and I have a column in both tables (for posts and topics) named 'deleted' if it equals 0 that means its displayed (considered not deleted/exists) or if it equals 1 it hidden (considered deleted/doesn't exist) - bool/lean. Now, the 'specific criteria' I'm on about...I'm wanting to get a total post count within a specific forum using its id (forum_id), ensuring it only counts posts which are not deleted (deleted = 0) and their parent topics are not deleted either (deleted = 0). The column/table names are self explanatory (see my efforts below for them - if needed). I've tried the following (using a 'simple' JOIN): SELECT COUNT(t1.post_id) FROM forum_posts AS t1, forum_topics AS t2 WHERE t1.forum_id = '{$forum_id}' AND t1.deleted = 0 AND t1.topic_id = t2.topic_id AND t2.deleted = 0 LIMIT 1 I've also tried this (using a Subquery): SELECT COUNT(t1.post_id) FROM forum_posts AS t1 WHERE t1.forum_id = '{$forum_id}' AND t1.deleted = 0 AND (SELECT deleted FROM forum_topics WHERE topic_id = t1.topic_id) = 0 LIMIT 1 But both don't comply with the specific criteria. Appreciate all help! :)

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  • TFS merging for users that are used to VSS

    - by JacksonD
    I just migrated a team of 7 developers from VSS to TFS. I migrated all of their code into a DEV folder which I then branched into a QA folder (which I branched into a PROD folder). The developers usually don't work on the same files, but there are some shared utility classes. All of the code is for a large ASP.NET web site. When the developers are ready to merge from DEV to QA, they only want to merge their changes. For example, let's say that Developer1 has been working on a project for the last 3 months and he's ready to merge all of his code into QA. However, Developer2 has been working on a different project for the last 2 months which is not ready to be merged. Developer1 and Developer2's changes are not in any way dependent on each other, but they are not separated into different folder structures and they each regularly do a get latest. There doesn't seem to be a way for developer1 to only merge his changes without also merging all of developer2's changes. Currently, developer1 is going through the Pending Changes window and 'Undoing Pending Changes' for all of Developer2's changes, but this is time consuming. They could merge each file individually, but this is also time consuming. Is there an easier way? I am going to have a coronary if I hear one more person explain how much easier it was to work in VSS.

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  • Why doesn't Firefox redownload images already on a page?

    - by vvo
    Hello, i just read this article : https://developer.mozilla.org/en/HTTP_Caching_FAQ There's a firefox behavior (and some other browsers i guess) i'd like to understand : if i take any webpage and try to insert the same image multiple times in javascript, the image is only downloaded ONCE even if i specifiy all needed headers to say "do no ever use cache". (see article) I know there are workarounds (like addind query strings to end of urls etc) but why do firefox act like that, if i say that an image do not have to be cached, why is the image still taken from cache when i try to re-insert it ? Plus, what cache is used for this ? (I guess it's the memory cache) Is this behavior the same for dynamic inclusion for example ? ANSWSER IS NO :) I just tested it and the same headers for a js script will make firefox redownload it each time you append the script to the DOM. PS: I know you're wondering WHY i need to do that (appending same image multiple times and force to redownload but this is the way our app works) thank you The good answer is : firefox will store images for the current page load in the memory cache even if you specify he doesnt have to cache them. You can't change this behavior but this is odd because it's not the same for javascript files for example Could someone explain or link to a document describing how firefox cache WORKS?

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  • Global State and Singletons Dependency injection

    - by Manu
    this is a problem i face lot of times when i am designing a new app i'll use a sample problem to explain this think i am writing simple game.so i want to hold a list of players. i have few options.. 1.use a static field in some class private static ArrayList<Player> players = new ArrayList<Integer>(); public Player getPlayer(int i){ return players.get(i); } but this a global state 2.or i can use a singleton class PlayerList{ private PlayerList instance; private PlayerList(){...} public PlayerList getInstance() { if(instance==null){ ... } return instance; } } but this is bad because it's a singleton 3.Dependency injection class Game { private PlayerList playerList; public Game(PlayerList list) { this.list = list; } public PlayerList getPlayerList() { return playerList; } } this seems good but it's not, if any object outside Game need to look at PlayerList (which is the usual case) i have to use one of the above methods to make the Game class available globally. so I just add another layer to the problem. didn't actually solve anything. what is the optimum solution ? (currently i use Singleton approach)

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  • Space between 2 vertices on a heightmap

    - by Sietse
    First off, I am sorry for the crazy title. I couldn't really think of something else. I am working on a hobby project, it's a infinite world generated with Perlin Noise, Java and LWJGL. But I am having a problem, it is kinda hard to explain, so I made a video: http://youtu.be/D_NUBJZ_5Kw Obviously the problem is the black spaces in between all the pieces of ground. I have no idea what is causing it. I already tried making all the values doubles instead of floats, but that didn't fix it. Here is a piece of code I am using: float height2, height = (float)getHeight(x, y); height2 = (float) ((getHeight(x-1, y+1) + height) / 2); vertexhelper.addVertexColorAndTexture(x, height2, y+1, r, g, b, a, 0f, 1f); height2 = (float) ((getHeight(x+1, y+1) + height) / 2); vertexhelper.addVertexColorAndTexture(x+1, height2, y+1, r, g, b, a, 1f, 1f); height2 = (float) ((getHeight(x+1, y-1) + height) / 2); vertexhelper.addVertexColorAndTexture(x+1, height2, y, r, g, b, a, 1f, 0f); height2 = (float) ((getHeight(x-1, y-1) + height) / 2); vertexhelper.addVertexColorAndTexture(x, height2, y, r, g, b, a, 0f, 0f); I loop through this at the initialization of a chunk with x-16 and y-16. vertexhelper is a class I made that just puts everything in a array. (I am using floats here, but that's after doing the maths, so that shouldn't be a problem) I highly appreciate you reading this.

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  • Still some questions about USB

    - by b-gen-jack-o-neill
    Hi, few days ago I asked here about implementing USB. Now, If I may, would like to ask few more questions, about thing I dind´t quite understood. So, first, If I am right, Windows has device driver for USB interface, for the physical device that sends and receives communication. But what this driver offers to system (user)? I mean, USB protocol is made so its devices are adressed. So you first adress device than send message to it. But how sophisticted is the device controller (HW) and its driver? Is it so sophisticated that it is a chip you just send device adress and data, and it writes the outcomming data out and incomming data to some internal register to be read, or thru DMA directly to memory? Or, how its drivers (SW) really work? Does its driver has some advanced functions like send _data to _device? Becouse I somewhat internally hope there is a way to directly send some data thru USB, maybe by calling USB drivers itself? Is there any good article, tutorial you know about to really explain how all this logic works? Thanks.

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  • How do you send email from IMAP account with PHP?

    - by arthurakay
    I'm having an issue sending email via PHP/IMAP - and I don't know if it's because: I don't correctly understand IMAP, or there's an issue with my server My application opens an IMAP connection to an email account to read messages in the inbox. It does this successfully. The problem I have is that I want to send messages from this account and have them display in the outbox/sent folder. As far as I can tell, the PHP imap_mail() function doesn't in any way hook into the IMAP stream I currently have open. My code executes without throwing an error. However, the email never arrives to the recipient and never displays in my sent folder. private function createHeaders() { return "MIME-Version: 1.0" . "\r\n" . "Content-type: text/html; charset=iso-8859-1" . "\r\n" . "From: " . $this->accountEmail . "\r\n"; } private function notifyAdminForCompleteSet($urlToCompleteSet) { $message = " <p> In order to process the latest records, you must visit <a href='$urlToCompleteSet'>the website</a> and manually export the set. </p> "; try { imap_mail( $this->adminEmail, "Alert: Manual Export of Records Required", wordwrap($message, 70), $this->createHeaders() ); echo(" ---> Admin notified via email!\n"); } catch (Exception $e) { throw new Exception("Error in notifyAdminForCompleteSet()"); } } I'm guessing I need to copy the message into the IMAP account manually... or is there a different solution to this problem? Also, does it matter if the domain in the "from" address is different than that of the server on whicn this script is running? I can't explain why the message is never sent.

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  • Why does the order of the loops affect performance when iterating over a 2D array? [closed]

    - by Mark
    Possible Duplicate: Which of these two for loops is more efficient in terms of time and cache performance Below are two programs that are almost identical except that I switched the i and j variables around. They both run in different amounts of time. Could someone explain why this happens? Version 1 #include <stdio.h> #include <stdlib.h> main () { int i,j; static int x[4000][4000]; for (i = 0; i < 4000; i++) { for (j = 0; j < 4000; j++) { x[j][i] = i + j; } } } Version 2 #include <stdio.h> #include <stdlib.h> main () { int i,j; static int x[4000][4000]; for (j = 0; j < 4000; j++) { for (i = 0; i < 4000; i++) { x[j][i] = i + j; } } }

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  • C++ STL 101: Overload function causes build error

    - by Sidjal
    Trivial code that works if I do not overload myfunc. void myfunc(int i) { std::cout << "calling myfunc with arg " << i << std::endl; } void myfunc(std::string s) { std::cout << "calling myfunc with arg " << s << std::endl; } void testalgos() { std::vector<int> v; v.push_back(1); v.push_back(2); std::vector<std::string> s; s.push_back("one"); s.push_back("two"); std::for_each( v.begin(), v.end(), myfunc); std::for_each( s.begin(), s.end(), myfunc); return; } int _tmain(int argc, _TCHAR* argv[]) { std::cout << "Hello World" << std::endl; testalgos(); return 0; } The following build errors repeat for both for_each calls. error C2914: 'std::for_each' : cannot deduce template argument as function argument is ambiguous error C2784: '_Fn1 std::for_each(_InIt,_InIt,_Fn1)' : could not deduce template argument for '_InIt' from 'std::_Vector_iterator<_Ty,_Alloc'. It does work if I do not overload myfunc.Can someone explain what is happening here. TIA

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  • What access token should i use?

    - by user548458
    I made a posting scores. It worked normaly sometimes. But, now I cant post any score. If I use user accessToken: string path = meID + "/scores"; var parameters = new Dictionary<string, object> (){ { "score", score.ToString () }, { "access_token", accessToken } }; facebook.post (path, parameters, ( error, obj ) => I get error: {"error":{"message":"(#15) This method must be called with an app access_token.", "type":"OAuthException", "code":15}} If I use an app access token: string path = meID + "/scores"; var parameters = new Dictionary<string, object> () { { "score", score.ToString () }, { "access_token", appAccessToken } }; facebook.post (path, parameters, ( error, obj ) => I get other error: {"error":{"message":"A user access token is required to request this resource.", "type":"OAuthException", "code":102}} Help me please, what am i doing wrong? PS: I worked well recently, but now - dont. Cant explain it...

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  • Calling function and running it

    - by devs
    I am quite new to objects and OOP. I really don't know how to explain it well but I'll try. So I am trying to read though JSON with JS, the JSON is passed from PHP. This would be easy if all of the information was on the same html page, but I' am trying something that I am new too. So let me show my code... First is the JS which is in app.js var Donors = function(){ var api = this.list; $(document).ready(function(){ $.getJSON(api, function(){ var donorObj = api.payload; $.each(donorObj, function(i, donor){ //console.log(donor.ign); }); }); }); } What I want this part to do is read from the JSON I'm giving it and console.log each name (or donor.ign) when the document is ready. On the html page, or header.php <script> $(function(){ var list = <?php cbProxy(); ?>; var Dons = new Donors(); Dons.list = list; }); </script> the data that's in list is the below JSON. You already know what the rest does, it just passes the JSON to the Donors() function. JSON example: { "code": 0, "payload": [ { "time": 1349661897, "packages": [ "49381" ], "ign": "Notch", "price": "15.99", "currency": "USD" } I'm use to just making functions and calling it on the same page or file and this is my first doing this kind of function. How can I get the function to run with the data I sent it so it console.log() each name.

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  • Sheet and thread memory problem

    - by Xident
    Hi Guys, recently I started a project which can export some precalculated Grafix/Audio to files, for after processing. All I was doing is to put a new Window (with progressindicator and an Abort Button) in my main xib and opened it using the following code: [NSApp beginSheet: REC_Sheet modalForWindow: MOTHER_WINDOW modalDelegate: self didEndSelector: nil contextInfo: nil]; NSModalSession session=[NSApp beginModalSessionForWindow:REC_Sheet]; RECISNOTDONE=YES; while (RECISNOTDONE) { if ([NSApp runModalSession:session]!=NSRunContinuesResponse) break; usleep(100); } [NSApp endModalSession:session]; A Background Thread (pthread) was started earlier, to actually perform the work and save all the targas/wave file. Which worked great, but after an amount of time, it turned out that the main thread was not responding anymore and my memory footprint raised unstoppable. I tried to debug it with Instruments, and saw a lot of CFHash etc stuff growing to infinity. By accident i clicked below the sheet, and temporary it helped, the main thread (AppKit ?) was releasing it's stuff, but just for a little time. I can't explain it to me, first of all I thought it was the access from my thread to the Progressbar to update the Progress (intervalled at 0,5sec), so I cut it out. But even if I'm not updating anything and did nothing with the Progressbar, my Application eat up all the Memory, because of not releasing it's "Main-Event" or whatsoever Stuff. Is there any possibility to "drain" this Main thread Memory stuff (Runloop / NSApp call?). And why the heck doesn't the Main thread respond anymore (after this simple task) ??? I don't have a clou anymore, please help ! Thanks in advance ! P.S. How do you guys implement "threaded long task" Stuff and updating your gui ???

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  • What does the destructor do silently?

    - by zhanwu
    Considering the following code which looks like that the destructor doesn't do any real job, valgrind showed me clearly that it has memory leak without using the destructor. Any body can explain me what does the destructor do in this case? #include <iostream> using namespace std; class A { private: int value; A* follower; public: A(int); ~A(); void insert(int); }; A::A(int n) { value = n; follower = NULL; } A::~A() { if (follower != NULL) delete follower; cout << "do nothing!" << endl; } void A::insert(int n) { if (this->follower == NULL) { A* f = new A(n); this->follower = f; } else this->follower->insert(n); } int main(int argc, char* argv[]) { A* objectA = new A(1); int i; for (i = 0; i < 10; i++) objectA->insert(i); delete objectA; }

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  • C# - Wait to finish before doing the next task

    - by Alex Ogden
    i have a server application with a richtextbox as the console text basically. The problem is, i have start, restart and stop buttons - But my restart button doesn't work. Heres my code for the restart button: consoletxt("RESTART", "Restarting Server..."); statuslabel1.Text = "Restarting"; statuslabel1.ForeColor = Color.Orange; statuslabel2.Text = "Restarting"; statuslabel2.ForeColor = Color.Orange; command("stop"); //The performclick just starts the server startbtn.PerformClick(); statuslabel1.Text = "Online"; statuslabel1.ForeColor = Color.DarkGreen; statuslabel2.Text = "Online"; statuslabel2.ForeColor = Color.DarkGreen; consoletxt("RESTART", "Restart completed, server online!"); However, the output is this: 2012-04-01 11:32:12 [RESTART] Restarting Server... 2012-04-01 11:32:12 [RESTART] Restart completed, server online! 2012-04-01 11:32:12 [INFO] CONSOLE: Stopping the server.. 2012-04-01 11:32:12 [INFO] Stopping server So, it says that the restart has finished in the text - but it hasn't - all it has done is stop the server. Please can sombody explain to me how to do this properly? Thanks!

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  • please help me to solve problem

    - by davit-datuashvili
    first of all this is not homework and nobody tag it as homewrok i did not understand this porblem can anybody explain me?this is not english problem it is just misunderstanding what problem say Consider the problem of neatly printing a paragraph on a printer. The input text is a sequence of n words of lengths l1 , l2 , . . . , ln , measured in characters. We want to print this paragraph neatly on a number of lines that hold a maximum of M characters each. Our criterion of “neatness” is as follows. If a given line contains words i through j , where i = j , and we leave exactly one space between words, the number of extra space characters at the end of the line is M - j + i -(k=i,k< j,k++) lk , which must be nonnegative so that the words fit on the line. We wish to minimize the sum, over all lines except the last, of the cubes of the numbers of extra space characters at the ends of lines. Give a dynamic-programming algorithm to print a paragraph of n words neatly on a printer. Analyze the running time and space requirements of your algorithm.

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  • Explaining a Ruby code snippet

    - by Michael Foukarakis
    I'm in that uncomfortable position again, where somebody has left me with a code snippet in a language I don't know and I have to maintain it. While I haven't introduced Ruby to myself some parts of it are quite simple, but I'd like to hear your explanations nonetheless. Here goes: words = File.open("lengths.txt") {|f| f.read }.split # read all lines of a file in 'words'? values = Array.new(0) words.each { |value| values << value.to_i } # looked this one up, it's supposed to convert to an array of integers, right? values.sort! values.uniq! diffs = Array.new(0) # this looks unused, unless I'm missing something obvious sum = 0 s = 0 # another unused variable # this looks like it's computing the sum of differences between successive # elements, but that sum also remains unused, or does it? values.each_index { |index| if index.to_i < values.length-1 then sum += values.at(index.to_i + 1) - values.at(index.to_i) end } # could you also explain the syntax here? puts "delta has the value of\n" # this will eventually print the minimum of the original values divided by 2 puts values.at(0) / 2 The above script was supposed to figure out the average of the differences between every two successive elements (integers, essentially) in a list. Am I right in saying this is nowhere near what it actually does, or am I missing something fundamental, which is likely considering I have no Ruby knowledge?

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  • Defining Views Based On Selection

    - by Wayne
    Well the title isn't very descriptive but I'm not exactly sure how to explain but here goes! I have a web application (can use either MVC or standard web forms) which a user signs in to. If the user has signed up for more than one product they will have the option to switch between them. For the sakes of this example lets say User1 signs in and has access to Product1, Product2 and Product3. Now, each product will be very different and offer different functionally. What I want is the main view to be focused around the product they have selected and not redirected to a sub domain. What I don't want to have to do is get them to go to www.mysite.com/product1 or www.mysite.com/product2 but simply www.mysite.com regardless of the product they have selected and have the site render the views etc for that product. Wow does any of that make any sense? I was thinking mabe the use of sessions or something and URL rewriting? Are there any sample apps out there that make use of the same kind of functionallity that I could take a look at? Thanks for any help I appreciate it!

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  • Is there a selector or a work around to select any element with no children.

    - by rnaud
    Looking at the CSS3 specs, I can't find any way to select any element that has no children. Let me explain. <body> <h1>Main Page</h1> <div id="main"> <div class="post"> <h2>Article 1</h1> <p>some text</p> </div> <div class="post"> <h2>Article 2</h1> <p>some text</p> </div> </div> </body> I'm looking for a CSS syntax to select the h1, the two h2 and the two p. A way to select in any page, all elements with no children. Any suggestion ? Sorry, I forgot to add the "empty" part, I am actually already using the *:empty selector, but it's not working for any tag that has a nodeText as a child. So it's working for any input, image, object, but not for h2, h1, or any p.

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  • Bizarre static_cast trick?

    - by Rob
    While perusing the Qt source code I came across this gem: template <class T> inline T qgraphicsitem_cast(const QGraphicsItem *item) { return int(static_cast<T>(0)->Type) == int(QGraphicsItem::Type) || (item && int(static_cast<T>(0)->Type) == item->type()) ? static_cast<T>(item) : 0; } Notice the static_cast<T>(0)->Type? I've been using C++ for many years but have never seen 0 being used in a static_cast before. What is this code doing and is it safe? Background: If you derive from QGraphicsItem you are meant to declare an unique enum value called Type that and implement a virtual function called type that returns it, e.g.: class Item : public QGraphicsItem { public: enum { Type = MAGIC_NUMBER }; int type() const { return Type; } ... }; You can then do this: QGraphicsItem* item = new Item; ... Item* derivedItem = qgraphicsitem_cast<Item*>(item); This will probably help explain what that static_cast is trying to do.

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  • SYN receives RST,ACK very frequently

    - by user1289508
    Hi Socket Programming experts, I am writing a proxy server on Linux for SQL Database server running on Windows. The proxy is coded using bsd sockets and in C, and it is working just fine. When I use a database client (written in JAVA, and running on a Linux box) to fire queries (with a concurrency of 100 or more) directly to the Database server, not experiencing connection resets. But through my proxy I am experiencing many connection resets. Digging deeper I came to know that connection from 'DB client' to 'Proxy' always succeeds but when the 'Proxy' tries to connect to the DB server the connection fails, due to the SYN packet getting RST,ACK. That was to give some background. The question is : Why does sometimes SYN receives RST,ACK? 'DB client(linux)' to 'Server(windows)' ---- Works fine 'DB client(linux) to 'Proxy(Linux)' to 'Server(windows)' ----- problematic I am aware that this can happen in "connection refused" case but this definitely is not that one. SYN flooding might be another scenario, but that does not explain fine behavior while firing to Server directly. I am suspecting some socket option setting may be required, that the client does before connecting and my proxy does not. Please put some light on this. Any help (links or pointers) is most appreciated. Additional info: Wrote a C client that does concurrent connections, which takes concurrency as an argument. Here are my observations: - At 5000 concurrency and above, some connects failed with 'connection refused'. - Below 2000, it works fine. But the actual problem is observed even at a concurrency of 100 or more. Note: The problem is time dependent sometimes it never comes at all and sometimes it is very frequent and DB client (directly to server) works fine at all times .

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  • Speeding up a group by date query on a big table in postgres

    - by zaius
    I've got a table with around 20 million rows. For arguments sake, lets say there are two columns in the table - an id and a timestamp. I'm trying to get a count of the number of items per day. Here's what I have at the moment. SELECT DATE(timestamp) AS day, COUNT(*) FROM actions WHERE DATE(timestamp) >= '20100101' AND DATE(timestamp) < '20110101' GROUP BY day; Without any indices, this takes about a 30s to run on my machine. Here's the explain analyze output: GroupAggregate (cost=675462.78..676813.42 rows=46532 width=8) (actual time=24467.404..32417.643 rows=346 loops=1) -> Sort (cost=675462.78..675680.34 rows=87021 width=8) (actual time=24466.730..29071.438 rows=17321121 loops=1) Sort Key: (date("timestamp")) Sort Method: external merge Disk: 372496kB -> Seq Scan on actions (cost=0.00..667133.11 rows=87021 width=8) (actual time=1.981..12368.186 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 32447.762 ms Since I'm seeing a sequential scan, I tried to index on the date aggregate CREATE INDEX ON actions (DATE(timestamp)); Which cuts the speed by about 50%. HashAggregate (cost=796710.64..796716.19 rows=370 width=8) (actual time=17038.503..17038.590 rows=346 loops=1) -> Seq Scan on actions (cost=0.00..710202.27 rows=17301674 width=8) (actual time=1.745..12080.877 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 17038.663 ms I'm new to this whole query-optimization business, and I have no idea what to do next. Any clues how I could get this query running faster?

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