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  • What is a simple way to add a timer to a method

    - by John
    The following is in C#. I'm trying to do something very simple (I think). I have a method that loads an XML document XDocument doc = XDocument.Load(uri); , but I don't want to tie up pc resources if there are issues (connectivity, document size, etc.). So I'd like to be able to add a timeout variable that will cut the method off after a given number of seconds. I'm a newbie when it comes to asynchronous programming and find it confusing that there are so many examples written so many different ways . . . and none of them appear simple. I'd like a simple solution, if possible. Here's my thoughts so far on possible solution paths: 1) A method that wraps the existing load public XDocument LoadXDocument(string uri, int timeout){ //code } 2) A wrapper, but as an extension method XDocument doc = XDocument.LoadWithTimeout(string uri, int timeout); 3) A generic extension method. Object obj = SomeStaticClass.LoadWithTimeout(??? method, int timeout); 3), on its face seems really nice, because it would mean being able to generically add timeouts to many different method calls and not specifically tied to one type of object, but I suspect that it is either i)impossible or ii) very difficult. Please assist. Thanks.

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  • Implemeting web-based autocomplete for structured input

    - by ravigad
    I am looking to implement web-based autocomplete for structured commands. So, for example, suppose I was trying to implement a web-based Windows command line with autocomplete, in such a case I would want to suggest all the available commands, then, once a user selects a command, all the options for that command, then if a user enters a switch (say '-' dash or '/' slash) then offer all the switches for that command and all the relevant values that can follow, and so on. All from the same text input box. If you have used version 4.0 of JIRA, I am thinking of something similar to the JQL search input box that they have implemented. I have not managed to find any tutorials that look at this scenario end-to-end (which is a shame, because it would be great to see more applications that do this). What I am looking for is some guidance on the steps needed to implement this solution: Do you have any experience implementing such a solution and if so what components did you use? Would you use a framework such as ANTLR to provide the available options to the end user? If not what would do? Sorry for raising such a general question, but my main problem is working out how the pieces fit together as opposed to, say, how to do autocomplete or how to parse/tokenize an input command...

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  • I'm annoyed with asp .net mvc action links? Is there something better in MVC3?

    - by Jonathon Kresner
    After almost 3 years with mvc I'm scratching my head. Is it just me, or does the way we specify links in asp .net mvc suck? @Html.ActionLink("Log Off", "LogOff", "Account") In the previews for mvc 1 we had the funky generic action links which gave us intellisense and compile checking, which I LOVED. I know they removed them because of performance issues and because you could not actually guarantee that the route would resolve all the time... However the default way of doing it just doesn't make me feel safe enough in a big application. I've also used T4Mvc with MVC2, to be honest, I didn't really like it. It's not part of the Mvc framework and frustrating to develop with especially with source control in big teams and continuous integration builds. I guess I could also import Mvc Futures and keep using the generic types (it's probably what I'll do). I'm just about to start a very big project and was wondering what other people are thinking? Is anyone else annoyed with the options or has a new solution? It seems like ActionLinks are the most basic & frequently used feature. Shouldn't there be a good out of the box solution, we're just about to hit revision 3 of this framework.

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  • How can I find the common ancestor of two nodes in a binary tree?

    - by Siddhant
    The Binary Tree here is not a Binary Search Tree. Its just a Binary Tree. The structure could be taken as - struct node { int data; struct node *left; struct node *right; }; The maximum solution I could work out with a friend was something of this sort - Consider this binary tree (from http://lcm.csa.iisc.ernet.in/dsa/node87.html) : The inorder traversal yields - 8, 4, 9, 2, 5, 1, 6, 3, 7 And the postorder traversal yields - 8, 9, 4, 5, 2, 6, 7, 3, 1 So for instance, if we want to find the common ancestor of nodes 8 and 5, then we make a list of all the nodes which are between 8 and 5 in the inorder tree traversal, which in this case happens to be [4, 9, 2]. Then we check which node in this list appears last in the postorder traversal, which is 2. Hence the common ancestor for 8 and 5 is 2. The complexity for this algorithm, I believe is O(n) (O(n) for inorder/postorder traversals, the rest of the steps again being O(n) since they are nothing more than simple iterations in arrays). But there is a strong chance that this is wrong. :-) But this is a very crude approach, and I'm not sure if it breaks down for some case. Is there any other (possibly more optimal) solution to this problem?

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  • boost multi_index partial indexes

    - by Gokul
    Hi, I want to implement inside boost multi-index two sets of keys with same search criteria but different eviction criteria. Say i have two sets of data with same search condition, but one set needs a MRU(Most Recently Used) list of 100 and the other set requires a MRU of 200. Say the entry is like this class Student { int student_no; char sex; std::string address; }; The search criteria is student_no, but for sex='m', we need MRU of 200 and for sex='f', we need a MRU of 100. Now i have a solution where in i introduce a new ordered index to maintain ordering. For example the IndexSpecifierList will be something like this typedef multi_index_container< Student, indexed_by< ordered_unique< member<Student, int, &Student::student_no> >, ordered_unique< composite_key< member<Student, char, &Student::sex>, member<Student, int, &Student::sex_specific_student_counter> > > > > student_set Now everytime, i am inserting a new one, i have to take a equal_range for that using index 2 and remove the oldest one and if something is getting re-used, i have to update it by incrementing the counter. Is there a better solution to this kind of problem? Thanks, Gokul.

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  • javascript error of unterminated string

    - by OM The Eternity
    I want pass a parameter of javascript functiona which is a string. This javascript function is a hintbox on mousehover.. and the string i am using is like this: Hemmed Finish: Every side/edge (1/2" to 2") of the banner are folded and glued (special vinyl solution) or heat pressed. This is the most common and best finish option. Stitched Finish: Every side/edge (1" to 2") of the banner are folded in the back and stitched/sewed with white thread. This is not a common option as thread can be seen on the banner. Now in the hintbox on mousehover the above given text has to be display as it is displayed above along with the paragraph break.. But when i pass the above as parameter in that function along with appending some backslashes to recognise some punctuation, iots till gives me javascript error of unterminated string... I am doing this: onMouseover="showhint('Hemmed Finish\: Every side/edge \(1/2\'\' to 2\'\'\) of the banner are folded and glued \(special vinyl solution\) or heat pressed. This is the most common and best finish option.Stitched Finish\: Every side/edge \(1\'\' to 2\'\'\) of the banner are folded in the back and stitched/sewed with white thread. This is not a common option as thread can be seen on the banner', this, event, '250px')" pls could u help me in rectifying the issue...

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  • Extracting DCT coefficients from encoded images and video

    - by misha
    Is there a way to easily extract the DCT coefficients (and quantization parameters) from encoded images and video? Any decoder software must be using them to decode block-DCT encoded images and video. So I'm pretty sure the decoder knows what they are. Is there a way to expose them to whomever is using the decoder? I'm implementing some video quality assessment algorithms that work directly in the DCT domain. Currently, the majority of my code uses OpenCV, so it would be great if anyone knows of a solution using that framework. I don't mind using other libraries (perhaps libjpeg, but that seems to be for still images only), but my primary concern is to do as little format-specific work as possible (I don't want to reinvent the wheel and write my own decoders). I want to be able to open any video/image (H.264, MPEG, JPEG, etc) that OpenCV can open, and if it's block DCT-encoded, to get the DCT coefficients. In the worst case, I know that I can write up my own block DCT code, run the decompressed frames/images through it and then I'd be back in the DCT domain. That's hardly an elegant solution, and I hope I can do better. Presently, I use the fairly common OpenCV boilerplate to open images: IplImage *image = cvLoadImage(filename); // Run quality assessment metric The code I'm using for video is equally trivial: CvCapture *capture = cvCaptureFromAVI(filename); while (cvGrabFrame(capture)) { IplImage *frame = cvRetrieveFrame(capture); // Run quality assessment metric on frame } cvReleaseCapture(&capture); In both cases, I get a 3-channel IplImage in BGR format. Is there any way I can get the DCT coefficients as well?

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  • When is Googling it wrong?

    - by Drahcir
    I've been going through Stack Overflow for quite a bit now and noticed certain people (usually experienced programmers) frown upon Googling (researching) certain problems. Since I myself tend to use Google quite a bit to solve certain programming related issues I found certain comments rather demoralising. Now some of you may have come here trigger happy to delete this post but I needed some clarification. I usually Google things that usually syntax related that I would have never figured out on my own. For example I once wondered how to access the properties of a class that I didn't have a direct relationship to. So after a bit of research I discovered reflection and got what I wanted. Now in another scenario is learning a new language, in my case Silverlight were it differs in certain aspects of .NET compared to say ASP.NET. A few weeks ago I had no idea how to load another Silverlight page (usercontrol) and had to Google my way to the solution which I found wasn't as simple as I had imagined. In scenario three is were I myself frown up, that is just stealing a huge chunk of code to avoid doing the work yourself, for example paging a HTML table using JavaScript, where one just copies and pastes the JavasSript code without as much as trying to understand how it works. I do admit I have done this once or twice before for trivial tasks that had very little time limit and weren't all that important but most of the time still have to throw away what I found because it took too much time to adapt it and get what I wanted out of it. In the last scenario, I sometimes have a piece of code that I would be really unhappy about, as in I find it sloppy or too overcomplicated and try to look on the Internet to see other ways to tackle the same problem, let's say filtering through a table. With the knowledge I acquire I learned new coding practices that help me work more efficiently like "Do not repeat yourself" and such. Now in your opinion when do you find it wrong to use Google (or any other researching tool) to find a solution to your problem?

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  • Calling NSFetchedResultsController & CoreData experts

    - by JK
    I am having a few nagging issues with NSFetchedResultsController and CoreData, any of which I would be very grateful to get help on. Issue 1 - Updates: I update my store on a background thread which results in certain rows being delete, inserted or updated. The changes are merged into the context on the main thread using the "mergeChangesFromContextDidSaveNotification:" method. Inserts and deletes are updated properly, but updates are not (e.g. the cell label is not updated with the change) although I have confirmed the updates to come through the contextDidSaveNotifcation, exactly like the inserts and deleted. My current workaround is to temporarily change the staleness interval of the context to 0, but this does not seem like the ideal solution. Issue 2 - Deleting objects: My fetch batch size is 20. If an object is deleted by the background thread which is in the first 20 rows, everything works fine. But if the object is after the first 20 rows and the table is scrolled down, a "CoreData could not fulfill a fault" error is raised. I have tried resaving the context and reperforming the frc fetch - all to no avail. Note: In this scenario, the frc delegate method "didChangeObject...." is not called for the delete - I assume this is because the object in question had not been faulted at that time (as it is was outside the initial fetch range). But for some reason, the context still thinks the object is around, although is has been deleted from the store. Issue 3 - Deleting sections : When the deletion of a row leads to the deletion of a section, I have gotten the "invalid number of rows in section???" error. I have worked around this by removing the "reloadSection" line from the NSFetchedResultsChangeMove: section and replacing it with "[tableView insertRowsAtIndexPaths...." This seems to work, but once again, I am not sure if this is the best solution. Any help would be greatly appreciated. Thank you!

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  • Integrate QT and OpenCV in Visual Studio

    - by user2891190
    Sorry If you feel that this is an already asked question. But I googled for more than 2 days any tried lots of solution which given through stackoverflow and referred lots of tutorials. But I couldn't get a proper idea. I am already working in a project which use c++(visual studio) with opencv which I am developing as my university project. I have developing this for last 2 months. But now I want to add a better UI.(Previously I considered only on the functionality) So I decided to move into QT. I'm new to QT. So I did some google search. I know that I can do this with the QT creator. But I want to do this in visual studio as the functionality of my project is bit complex. What I already know is I have to build opencv with Qt using cmake. I followed few tutorials. But most of the tutorials use mingw and QT creator. http://www.anlak.com/build-debug-opencv-vs2010/ Accoring to above tutorial I generated a visual studio project using cmake. But when I tried to open that solution file my visual studio becomes not-responding. I can't figure out the reason. I tried two days and I couldn't find a proper tutorial which describes integration of QT and opencv in visual studio. So can someone give me the instruction to integrate QT and Opencv in visual studio.

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  • How do I see if an established socket is stuck on a server that's expecting input?

    - by Parker
    I have a script that scans ports for open proxy servers. Problem is if it encounters a login program (specifically telnet) then it hangs there forever since it doesn't know what to do and eventually the server closes the connection. The simple solution would be to create a bunch of cases. If telnet, do this. If SSH, do that. If something else, blah blah blah. I'd like an umbrella solution since the script is not a high priority for me. The script, as it is now, is available at http://parkrrr.net/socks/scan.phps On a small scale (the page maybe averages 15 hits/day) it's fine but on a larger scale I'd be worried about a lot of open zombie sockets. Swapping the !$strpos doesn't work since servers can return more information than what you requested (headers, ads, etc). Only accepting a fixed number of bytes (as opposed to appending until EOF, which it does now) from the $fgets also does not seem to work. I am sure this is where it gets stuck: while (!feof($fp)) { $data.=fgets($fp,512); } But what can I do? Any other suggestions/warnings would also be welcomed.

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  • Round time to 5 minute nearest SQL Server

    - by Drako
    i don't know if it can be usefull to somebody but I went crazy looking for a solution and ended up doing it myself. Here is a function that (according to a date passed as parameter), returns the same date and approximate time to the nearest multiple of 5. It is a slow query, so if anyone has a better solution, it is welcome. A greeting. CREATE FUNCTION [dbo].[RoundTime] (@Time DATETIME) RETURNS DATETIME AS BEGIN DECLARE @min nvarchar(50) DECLARE @val int DECLARE @hour int DECLARE @temp int DECLARE @day datetime DECLARE @date datetime SET @date = CONVERT(DATETIME, @Time, 120) SET @day = (select DATEADD(dd, 0, DATEDIFF(dd, 0, @date))) SET @hour = (select datepart(hour,@date)) SET @min = (select datepart(minute,@date)) IF LEN(@min) > 1 BEGIN SET @val = CAST(substring(@min, 2, 1) as int) END else BEGIN SET @val = CAST(substring(@min, 1, 1) as int) END IF @val <= 2 BEGIN SET @val = CAST(CAST(@min as int) - @val as int) END else BEGIN IF (@val <> 5) BEGIN SET @temp = 5 - CAST(@min%5 as int) SET @val = CAST(CAST(@min as int) + @temp as int) END IF (@val = 60) BEGIN SET @val = 0 SET @hour = @hour + 1 END IF (@hour = 24) BEGIN SET @day = DATEADD(day,1,@day) SET @hour = 0 SET @min = 0 END END RETURN CONVERT(datetime, CAST(DATEPART(YYYY, @day) as nvarchar) + '-' + CAST(DATEPART(MM, @day) as nvarchar) + '-' + CAST(DATEPART(dd, @day) as nvarchar) + ' ' + CAST(@hour as nvarchar) + ':' + CAST(@val as nvarchar), 120) END

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  • Develop multiple very similar projects at once

    - by Raveren
    I am developing a semi-complicated site that is available in several countries at once. Much effort has been put in to make the code bases as similar as possible to one another and ultimately only the config file and some representational data will differ between them. Each project has its own SVN repository which maps directly to a live test site. That part is handled by the IDE we use to work. Now I am in need to create a some sort of system to keep all these projects in sync. The best theoretical solution so far is to create a local hook script that would fire on committing and Merge the committed files from the project that is being committed to all other projects Optionally upload them to the live site, replacing previous files The first problem is that I don't know how I would do the merging - I guess it would be like applying a SVN patch or something. The second is if I do not want to upload the changes to the live server, how would I go about synching the live and local code bases (replace older files?). I am posting this question, not going through the potentially huge trouble of solving the aforementioned problems myself is that I believe this is a pretty common situation and someone would already have a solution and others may benefit from the answers in the future. Lastly, I'm on windows7, develop PHP and use tortoiseSVN.

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  • implement AOP for Controllers in Spring 3

    - by tommy
    How do I implement AOP with an annotated Controller? I've search and found two previous posts regarding the problem, but can't seem to get the solutions to work. posted solution 1 posted solution 2 Here's what I have: Dispatch Servlet: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <context:annotation-config/> <context:component-scan base-package="com.foo.controller"/> <bean id="fooAspect" class="com.foo.aop.FooAspect" /> <aop:aspectj-autoproxy> <aop:include name="fooAspect" /> </aop:aspectj-autoproxy> </beans> Controller: @Controller public class FooController { @RequestMapping(value="/index.htm", method=RequestMethod.GET) public String showIndex(Model model){ return "index"; } } Aspect: @Aspect public class FooAspect { @Pointcut("@target(org.springframework.stereotype.Controller)") public void controllerPointcutter() {} @Pointcut("execution(* *(..))") public void methodPointcutter() {} @Before("controllerPointcutter()") public void beforeMethodInController(JoinPoint jp){ System.out.println("### before controller call..."); } @AfterReturning("controllerPointcutter() && methodPointcutter() ") public void afterMethodInController(JoinPoin jp) { System.out.println("### after returning..."); } @Before("methodPointcutter()") public void beforeAnyMethod(JoinPoint jp){ System.out.println("### before any call..."); } } The beforeAnyMethod() works for methods NOT in a controller; I cannot get anything to execute on calls to controllers. Am I missing something?

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  • Dealing with image upload on server

    - by user1073320
    I have got a the following problem: I have got multi-step form where in one step user upload image to server and then few steps further supplies other information, when this information is invalid no data should be commited - also the image should be deleted. I was thinking about PHP session, but I've read here PHP - Store Images in SESSION data? that it is inefficient way. Every time you proceed step in the form the image is reloaded (in the session) and as somebody mentioned "You will want it to only be as big as it needs to be and you need to delete it as soon as you don't need it because large pieces of information in the session will slow down the session startup." - here i got a question: will it slow down the stratup the session of user who upload file or sessions of all users? I have to mention that I'm looking for solution that doesn't rely on operating system scripts (cron or etc) - I have no permission to run such scripts. The perfect solution for me would be: saving image on disk (for example in some folder named after session id) then after the latest step of form move this image or delete depending on form validation. If user unexpectedly destroy the session (for example closing the browser) of course the folder with image should be deleted. In nutshell I need somethig like callback to event "destroying session".

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  • algorithm to find longest non-overlapping sequences

    - by msalvadores
    I am trying to find the best way to solve the following problem. By best way I mean less complex. As an input a list of tuples (start,length) such: [(0,5),(0,1),(1,9),(5,5),(5,7),(10,1)] Each element represets a sequence by its start and length, for example (5,7) is equivalent to the sequence (5,6,7,8,9,10,11) - a list of 7 elements starting with 5. One can assume that the tuples are sorted by the start element. The output should return a non-overlapping combination of tuples that represent the longest continuos sequences(s). This means that, a solution is a subset of ranges with no overlaps and no gaps and is the longest possible - there could be more than one though. For example for the given input the solution is: [(0,5),(5,7)] equivalent to (0,1,2,3,4,5,6,7,8,9,10,11) is it backtracking the best approach to solve this problem ? I'm interested in any different approaches that people could suggest. Also if anyone knows a formal reference of this problem or another one that is similar I'd like to get references. BTW - this is not homework. Edit Just to avoid some mistakes this is another example of expected behaviour for an input like [(0,1),(1,7),(3,20),(8,5)] the right answer is [(3,20)] equivalent to (3,4,5,..,22) with length 20. Some of the answers received would give [(0,1),(1,7),(8,5)] equivalent to (0,1,2,...,11,12) as right answer. But this last answer is not correct because is shorter than [(3,20)].

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  • Facebook Connect: Permissions Error [200] using "stream.publish" with PHP

    - by Sarah
    Hi all, I've been implementing Facebook Connect into a site and am using both the PHP API, to allow me to automatically post data to a user's wall, as well as the JS API, for manual posting, permissions dialogs, etc. When the user uses the manual method it works 100%...the popups are displayed correctly, and the data gets posted to their wall properly. However, when I try to use the PHP API I am getting inconsistencies. When I try posting automatically using the PHP API using one account it works perfect, every time. But for some other accounts it never works, always returning "Permissions error." The error code is 200, and I've checked the Facebook API documentation and it's pretty vague, saying only "Permissions error. The application does not have permission to perform this action." But that's not true, since it works on some accounts and doesn't work on others. First, I've made sure that the users in question have enabled the extended permission "publish_stream" and that the manual method using the JS API works, so it doesn't seem to be a problem with those specific permissions. There are no apparent differences between the Facebook accounts I've used. So my question is has anyone run into this problem and found a solution to it? Is there some sort of other permission setting that users must enable for this to work? I've been searching Google and these forums but have not found any solution. The request I am sending is: (Note: The content/image url/link url are not the actual data I use) $attachment = array( 'caption' => '{*actor*} commented on <title> "<comment>"', 'media' => array( array( 'type' => 'image', 'src' => 'http://www.test.com/image.jpg', 'href' => 'http://www.test.com' ) ) ); $Facebook->api_client->stream_publish('', $attachment); Thanks, Sarah

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  • Help me refactor my World Cup Challenge Script

    - by kylemac
    I am setting up a World Cup Challenge between some friends, and decided to practice my Ruby and write a small script to automate the process. The Problem: 32 World Cup qualifiers split into 4 tiers by their Fifa ranking 8 entries Each entry is assigned 1 random team per tier Winner takes all :-) I wrote something that suffices yet is admittedly brute force. But, in my attempt to improve my Ruby, I acknowlege that this code isn't the most elegant solution around - So I turn to you, the experts, to show me the way. It may be more clear to check out this gist - https://gist.github.com/91e1f1c392bed8074531 My Current (poor) solution: require 'yaml' @teams = YAML::load(File.open('teams.yaml')) @players = %w[Player1 Player2 Player3 Player4 Player5 Player6 Player7 Player8] results = Hash.new players = @players.sort_by{rand} players.each_with_index do |p, i| results[p] = Array[@teams['teir_one'][i]] end second = @players.sort_by{rand} second.each_with_index do |p, i| results[p] << @teams['teir_two'][i] end third = @players.sort_by{rand} third.each_with_index do |p, i| results[p] << @teams['teir_three'][i] end fourth = @players.sort_by{rand} fourth.each_with_index do |p, i| results[p] << @teams['teir_four'][i] end p results I am sure there is a better way to iterate through the tiers, and duplicating the @players object ( dup() or clone() maybe?) So from one Cup Fan to another, help me out.

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  • C++: inheritance problem

    - by Helltone
    It's quite hard to explain what I'm trying to do, I'll try: Imagine a base class A which contains some variables, and a set of classes deriving from A which all implement some method bool test() that operates on the variables inherited from A. class A { protected: int somevar; // ... }; class B : public A { public: bool test() { return (somevar == 42); } }; class C : public A { public: bool test() { return (somevar > 23); } }; // ... more classes deriving from A Now I have an instance of class A and I have set the value of somevar. int main(int, char* []) { A a; a.somevar = 42; Now, I need some kind of container that allows me to iterate over the elements i of this container, calling i::test() in the context of a... that is: std::vector<...> vec; // push B and C into vec, this is pseudo-code vec.push_back(&B); vec.push_back(&C); bool ret = true; for(i = vec.begin(); i != vec.end(); ++i) { // call B::test(), C::test(), setting *this to a ret &= ( a .* (&(*i)::test) )(); } return ret; } How can I do this? I've tried two methods: forcing a cast from B::* to A::*, adapting a pointer to call a method of a type on an object of a different type (works, but seems to be bad); using std::bind + the solution above, ugly hack; changing the signature of bool test() so that it takes an argument of type const A& instead of inheriting from A, I don't really like this solution because somevar must be public.

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  • best database design for city zip & state tables

    - by ryan a
    My application will need to reference addresses. Street info will be stored with my main objects but the rest needs to be stored seperately to reduce redundancy. How should I store/retrieve ZIPs, cities and states? Here are some of my ideas. single table solution (cant do relationships) [locations] locationID locationParent (FK for locationID - 0 for state entries) locationName (city, state) locationZIP two tables (with relationships, FK constraints, ref integrity) [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName zipCode three tables [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName [zip] zipID cityID (FK for city.cityID) zipName Then I read into ZIP codes amd how they are assigned. They aren't specifically related to cities. Some cities have more than one ZIP (ok will still work) but some ZIPs are in more than one city (oh snap) and some other ZIPs (very few) are in more than one state! Also some ZIPs are not even in the same state as the address they belong to at all. Seems ZIPs are made for carrier route identification and some remote places are best served by post offices in neighboring cities or states. Does anybody know of a good (not perfect) solution that takes this into consideration to minimize discrepencies as the database grows?

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  • MySQL: Limit rows linked to each joined row

    - by SolidSnakeGTI
    Hello, Specifications: MySQL 4.1+ I've certain situation that requires certain result set from MySQL query, let's see the current query first & then ask my question: SELECT thread.dateline AS tdateline, post.dateline AS pdateline, MIN(post.dateline) FROM thread AS thread LEFT JOIN post AS post ON(thread.threadid = post.threadid) LEFT JOIN forum AS forum ON(thread.forumid = forum.forumid) WHERE post.postid != thread.firstpostid AND thread.open = 1 AND thread.visible = 1 AND thread.replycount >= 1 AND post.visible = 1 AND (forum.options & 1) AND (forum.options & 2) AND (forum.options & 4) AND forum.forumid IN(1,2,3) GROUP BY post.threadid ORDER BY tdateline DESC, pdateline ASC As you can see, mainly I need to select dateline of threads from 'thread' table, in addition to dateline of the second post of each thread, that's all under the conditions you see in the WHERE CLAUSE. Since each thread has many posts, and I need only one result per thread, I've used GROUP BY CLAUSE for that purpose. This query will return only one post's dateline with it's related unique thread. My questions are: How to limit returned threads per each forum!? Suppose I need only 5 threads -as a maximum- to be returned for each forum declared in the WHERE CLAUSE 'forum.forumid IN(1,2,3)', how can this be achieved. Is there any recommendations for optimizing this query (of course after solving the first point)? Notes: I prefer not to use sub-queries, but if it's the only solution available I'll accept it. Double queries not recommended. I'm sure there's a smart solution for this situation. Appreciated advice in advance :)

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  • efficient thread-safe singleton in C++

    - by user168715
    The usual pattern for a singleton class is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) inst = new Foo(...); return *inst; } However, it's my understanding that this solution is not thread-safe, since 1) Foo's constructor might be called more than once (which may or may not matter) and 2) inst may not be fully constructed before it is returned to a different thread. One solution is to wrap a mutex around the whole method, but then I'm paying for synchronization overhead long after I actually need it. An alternative is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) { pthread_mutex_lock(&mutex); if(inst == NULL) inst = new Foo(...); pthread_mutex_unlock(&mutex); } return *inst; } Is this the right way to do it, or are there any pitfalls I should be aware of? For instance, are there any static initialization order problems that might occur, i.e. is inst always guaranteed to be NULL the first time getInst is called?

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  • I have a bunch of template parameters that I want to hide from my users. How can I do this?

    - by Alex
    I have a superclass which is defined in terms of a few internal types it uses. Subclassing is performed as so: template <class InternalType1, class InternalType2> class Super { ... } class Sub : Super <interalTypeClass1, interalTypeClass2> { ... } But when I want to write a function that takes a pointer to the superclass, this happens : template <class InternalType1, class InternalType2> void function(Super<InternalType1, InternalType2>* in) { ... } The user really shouldn't know anything about the inside classes, and should really just concern himself with the use of the function. Some of these template lists become very very large, and expecting the user to pass them every time is wasteful, in my opinion. Any suggestions? EDIT: The function needs to know the internal types in use, so unless there is a way to access template types at compile time, I think there is no solution? Potential solution: Have each class do the following: #define SubTemplateArgs <SubTypeName, SubInternalType1, SubInternalType2> ?

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  • Why aren't variables declared in "try" in scope in "catch" or "finally"?

    - by Jon Schneider
    In C# and in Java (and possibly other languages as well), variables declared in a "try" block are not in scope in the corresponding "catch" or "finally" blocks. For example, the following code does not compile: try { String s = "test"; // (more code...) } catch { Console.Out.WriteLine(s); //Java fans: think "System.out.println" here instead } In this code, a compile-time error occurs on the reference to s in the catch block, because s is only in scope in the try block. (In Java, the compile error is "s cannot be resolved"; in C#, it's "The name 's' does not exist in the current context".) The general solution to this issue seems to be to instead declare variables just before the try block, instead of within the try block: String s; try { s = "test"; // (more code...) } catch { Console.Out.WriteLine(s); //Java fans: think "System.out.println" here instead } However, at least to me, (1) this feels like a clunky solution, and (2) it results in the variables having a larger scope than the programmer intended (the entire remainder of the method, instead of only in the context of the try-catch-finally). My question is, what were/are the rationale(s) behind this language design decision (in Java, in C#, and/or in any other applicable languages)?

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  • How to create a desktop shortcut to a website with website logo as icon?

    - by Wbdvlpr
    Hi I need a solution which allows users to create a desktop shortcut to a website, preferably with website logo as shortcut icon. There are ways users can create shortcut such as drag drop favicon or right click create new shortcut etc. This works but also creates the shortcut with default IE icon on windows. I am trying to avoid this method for this icon and some other reasons. I thought of creating a website-title.URL file, and tell users to download and save file to their desktop, again this works but doesn't solve the icon problem as the website logo (.ico) has to be at local disk and at a pre-specified location [IconFile=path]. I was wondering if it is possible to create a some sort of installer or windows application which users can download from the website. Once its executed by user, it creates this .URL file on user desktop which have IconFile path pre-specified, and copy the website-logo.ico at path specified in .URL file etc. So my questions are - Is it possible to create such a solution? What programming languages can be used to achieve this? Can this installer/app be made to work on non-windows machines as well? From developments point of view how big project it is? if I have to hire a programmer to do this. Please let me know if you need more information. Thanks

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