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• Memory leak with ContextMenuStrip

  - by Dave

  I'm creating a lot of custom controls and adding them to a FlowLayoutPanel. There is also a ContextMenuStrip created and populated at design time. Every time a control is added to the panel it has its ContextMenuStrip property assigned to this menu, so that all controls "share" the same menu. But I noticed when the controls are removed from the panel and disposed of, the memory in use in Task Manager doesn't drop. It rises around 50kB every time a control is created and added to the layout panel. I downloaded the trial of .NET Memory Profiler and it showed there were references to the menu strip hanging around after the controls were disposed. I changed the code to explicitly set the ContextMenuStrip property to null before disposing of the control, and yep, the memory is now released. Why is this? Shouldn't the GC clean up this type of thing?

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• O(log N) == O(1) - Why not?

  - by phoku

  Whenever I consider algorithms/data structures I tend to replace the log(N) parts by constants. Oh, I know log(N) diverges - but does it matter in real world applications? log(infinity) < 100 for all practical purposes. I am really curious for real world examples where this doesn't hold. To clarify: I understand O(f(N)) I am curious about real world examples where the asymptotic behaviour matters more than the constants of the actual performance. If log(N) can be replaced by a constant it still can be replaced by a constant in O( N log N). This question is for the sake of (a) entertainment and (b) to gather arguments to use if I run (again) into a controversy about the performance of a design.

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• Count of memory copies in *nix systems between packet at NIC and user application?

  - by Michael_73

  Hi there, This is just a general question relating to some high-performance computing I've been wondering about. A certain low-latency messaging vendor speaks in its supporting documentation about using raw sockets to transfer the data directly from the network device to the user application and in so doing it speaks about reducing the messaging latency even further than it does anyway (in other admittedly carefully thought-out design decisions). My question is therefore to those that grok the networking stacks on Unix or Unix-like systems. How much difference are they likely to be able to realise using this method? Feel free to answer in terms of memory copies, numbers of whales rescued or areas the size of Wales ;) Their messaging is UDP-based, as I understand it, so there's no problem with establishing TCP connections etc. Any other points of interest on this topic would be gratefully thought about! Best wishes, Mike

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• MongoDB: embedding performance question

  - by Alex

  I just started learning MongoDB, and I really like the idea of embedding collections instead of referencing them. MongoDB's documentation recommends to use embedding if performance is needed. I just thought about a simple forum model. Let's say, every board category has several boards, every board has several topics, and every topic has several messages. All of these collections are embedded. After some time the size of the board category will be huge. Way more than the 2MB limit. Does this mean that there's a flaw in this design?

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• BDD-testing using a UI driver (e.g. Selenium for a web-application)

  - by jonathanconway

  Can BDD (Behavior Driven Design) tests be implemented using a UI driver? For example, given a web application, instead of: Writing tests for the back-end, and then more tests in Javascript for the front-end Should I: Write the tests as Selenium macros, which simulate mouse-clicks, etc in the actual browser? The advantages I see in doing it this way are: The tests are written in one language, rather than several They're focussed on the UI, which gets developers thinking outside-in They run in the real execution environment (the browser), which allows us to Test different browsers Test different servers Get insight into real-world performance Thoughts?

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• Setting asp:Image URL using Javascript function

  - by Anil

  Hi all I have a series of asp:ImageButtons and one asp:Image(Big). Clicking on each ImageButton should change the ImageUrl of asp:Image to a new ImageUrl. How can we handle this using one Javascript function. Because I dont wanna code ImageButton_Click for each and every asp:ImageButton. This makes my application run very slow and also pass too many server requests. Any ideas ????How to design one powerful Javascript function. By the way when the user clicks on ImageButton...the ImageUrl that has to be set to asp:Image(Big) is same as that of ImageButton. This might help a bit. Thanks in advance

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• Display fraction with numerator/denominator with empty fields for users to enter text

  - by Anil

  Hi all I have a scenario in which I need to design online keyboard with buttons implementing different mathematical functions in ASP.NET. For example 1) A button called "Fraction" Onclicking= should display A numerator and a denominator separated by '-' with empty fields. Just as we write fractions manually. Now when the user clicks on this button the cursor should focus on numerator displaying 'the division line' and then by pressing 'Down' arrow key(on computr keyboard) should focus on denominator allowing users to enter both fields. Keeping it simple the user should be able to toggle between numerator and denominator. Please help me with some sample code. I have got no idea. Thanks in advance

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• How would I create a technology standards document for my company?

  - by Rob O

  I'm a Director of Product Engineering for my company. My CEO has asked me to create a technology standards document, explaining things like the technology we use, our policy on adapting to new technology, and design standards like percent of code covered by unit tests. I've never had to do something like this, and I've spent a significant amount of time searching the web for examples, but I haven't found any at all. The closest I've found are documents describing technical specifications for an individual product. However, I'm trying to define this for the entire company. Can someone provide examples of how this document could be formatted/organized, and what the typical content would be? Thanks!

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• Cast Object to JTable?

  - by Chris

  I am trying to implement a ListSelectionListener for some of my JTables. Simply (at the moment) the ListSelectionListener is supposed to simply return the text of the cell that was selected. My program design has several JTables and I would like to have one ListSelectionListener work for them all. In the valueChanged event of the ListSelectionListener I thought it was possible to do something like: private class SelectionHandler implements ListSelectionListener { public void valueChanged(ListSelectionEvent e) { JTable table = (JTable)e.getSource(); String data = (String) table.getValueAt(table.getSelectedRow(), 0); // Print data } } But when I do this I a ClassCastException error. Is there a way to do something like this? One solution I thought of was to compare the source of the event (e.getSource()) to all my JTables to see if they were equivalent (big if block) and then just calling .getValueAt inside that block but that would making the code in the future difficult if tables were to be added or removed.

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• Store interface in array list java

  - by agazerboy

  Hi all, I am learning java. I am trying to use composite design pattern. I am trying to use following logic. ( Don't laugh I know it is very basic :) ) Item -> interface Folder -> class File -> class In folder class, can I create an arraylist of Item to store files information? ArrayList<Item> info = ArrayList<Item>(); Or should I use Folder Arraylist? ArrayList<Folder> info = ArrayList<Folder>(); I don't know if interface can store real data as there is no variable just function definitions. Thanks for helping a newbie :)

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• Advanced queries in HBase

  - by Teflon Ted

  Given the following HBase schema scenario (from the official FAQ)... How would you design an Hbase table for many-to-many association between two entities, for example Student and Course? I would define two tables: Student: student id student data (name, address, ...) courses (use course ids as column qualifiers here) Course: course id course data (name, syllabus, ...) students (use student ids as column qualifiers here) This schema gives you fast access to the queries, show all classes for a student (student table, courses family), or all students for a class (courses table, students family). How would you satisfy the request: "Give me all the students that share at least two courses in common"? Can you build a "query" in HBase that will return that set, or do you have to retrieve all the pertinent data and crunch it yourself in code?

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• How can I do printing in Java with layouts instead of low level coordinates?

  - by Jonas

  I need to to some printing from my Java Swing application. I have tried to use Java Tutorials, but everything is very low level, and time-consuming. I have to specify the coordinates for every line that I want to print. It it also very lowlevel to use text, because I have to use FontMetrics and calculate what space all text fills up. Is there any easier way to to printing in Java? I would like to design the documents with something like layout managers instead. Any good library or API?

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• C++ boost ublas + units dimension constraints

  - by aaa

  hello. I am seeking advice on design/general idea on how to force matrix dimension constraints on ublas matrix/vector possibly using boost units. For example, let matrix A have dimensions of time x force (for example) // does not have dimensions, time x force and force x time are not distinguished. matrix<double> A; //something like? dimension<time, force, matrix<double> > A; dimension<force, time, matrix<double> > B = trans(A); have you done something like this or do you have some good idea about how to organize such constraints? Thank you

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• C#: Why only integral enums?

  - by JamesBrownIsDead

  I've been writing C# for seven years now, and I keep wondering, why do enums have to be of an integral type? Wouldn't it be nice to do something like: enum ErrorMessage { NotFound: "Could not find", BadRequest: "Malformed request" } Is this a language design choice, or are there fundamental incompatibilities on a compiler, CLR, or IL level? Do other languages have enums with string or complex (i.e. object) types? What languages? (I'm aware of workarounds; my question is, why are they needed?) EDIT: "workarounds" = attributes or static classes with consts :)

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• Training new employees on undocumented code

  - by glowcoder

  Our company has a large codebase (2500+ classes/interfaces in just the core alone, many more in other projects) for our flagship software product. We've never really hired more than one developer at a time, so we don't have a real training process. We're going to be bringing in 2-5 more developers now, and probably more in the near future (to put things into perspective, we have 7 right now.) Obviously, we would like to get these guys up to speed as soon as possible. The catch - almost all of our classes (95%+) are completely undocumented. No javadoc, no design docs, basically completely undocumented. What strategies can we employ to bring the new developers up to speed? I'd like to consider situations that include the existing code getting documented, but it's possible management won't allow for the time to get that done, so I also must consider situations where that won't happen. Has anyone been there before? What worked well for you? Thanks!

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• Displaying a collection of controls in a specific way in WPF

  - by Alvaro

  I have a collection of controls "MyCollection" wich changes in the Runtime. And I have to follow some constraints for that, for example: If my parameter "MyCollection.Count = 4" the property "NumberOfcolumns" will have the value 2, in order to create new Lines, and show the controls Two per Two. This is how I'm displaying my collection : <ItemsControl ItemsSource="{Binding MyCollection}" BorderThickness="0" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" > <ItemsControl.ItemsPanel> <ItemsPanelTemplate > <UniformGrid Columns="{Binding NumberOfColumns}" VerticalAlignment="Center" HorizontalAlignment="Center" Background="Transparent"/> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> The problem is that my controls have different sizes, and as In UniformGrids, Cells are uniform... My design is not really pretty, because I have little controls shown in big Cells !! Can someone help me to solve this problem ? NB: Please give me a detailled solution if possible, not something like : "Use WrapPanel..."

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• How to subscribe to EventHandler of a private control outside of Form

  - by randooom

  Hi all, maybe my design is not good, or I don't see the obvious solution, but I want to subscribe to a buttonClick EventHandler of Form1 from outside form1. For example I have a Controller and Form1 who are both instanced in the main function. Now I want to subscribe a function from Controller to the buttonClick event from Button1_Click in Form1. But the button1 is declarded private, so i can't do form1->Button1->Click += gcnew EventHandler(controller->function) Is there any way to get around this? Ok I could write a setter or something in Form1, but is there any other solution? I read some examples, but they are all calling events from within the same class so they don't address my specific problem.

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• Nginx fastcgi problems with django (double slashes in url?)

  - by wizard

  I'm deploying my first django app. I'm familiar with nginx and fastcgi from deploying php-fpm. I can't get python to recognize the urls. I'm also at a loss on how to debug this further. I'd welcome solutions to this problem and tips on debugging fastcgi problems. Currently I get a 404 page regardless of the url and for some reason a double slash For http://www.site.com/admin/ Page not found (404) Request Method: GET Request URL: http://www.site.com/admin// My urls.py from the debug output - which work in the dev server. Using the URLconf defined in ahrlty.urls, Django tried these URL patterns, in this order: ^listings/ ^admin/ ^accounts/login/$ ^accounts/logout/$ my nginx config server { listen 80; server_name beta.ahrlty.com; access_log /home/ahrlty/ahrlty/logs/access.log; error_log /home/ahrlty/ahrlty/logs/error.log; location /static/ { alias /home/ahrlty/ahrlty/ahrlty/static/; break; } location /media/ { alias /usr/lib/python2.6/dist-packages/django/contrib/admin/media/; break; } location / { include /etc/nginx/fastcgi_params; fastcgi_pass 127.0.0.1:8001; break; } } and my fastcgi_params fastcgi_param QUERY_STRING $query_string; fastcgi_param REQUEST_METHOD $request_method; fastcgi_param CONTENT_TYPE $content_type; fastcgi_param CONTENT_LENGTH $content_length; fastcgi_param SCRIPT_NAME $fastcgi_script_name; fastcgi_param REQUEST_URI $request_uri; fastcgi_param DOCUMENT_URI $document_uri; fastcgi_param DOCUMENT_ROOT $document_root; fastcgi_param SERVER_PROTOCOL $server_protocol; fastcgi_param GATEWAY_INTERFACE CGI/1.1; fastcgi_param SERVER_SOFTWARE nginx/$nginx_version; fastcgi_param REMOTE_ADDR $remote_addr; fastcgi_param REMOTE_PORT $remote_port; fastcgi_param SERVER_ADDR $server_addr; fastcgi_param SERVER_PORT $server_port; fastcgi_param SERVER_NAME $server_name; fastcgi_param PATH_INFO $fastcgi_script_name; # PHP only, required if PHP was built with --enable-force-cgi-redirect fastcgi_param REDIRECT_STATUS 200; And lastly I'm running fastcgi from the commandline with django's manage.py. python manage.py runfcgi method=threaded host=127.0.0.1 port=8080 pidfile=mysite.pid minspare=4 maxspare=30 daemonize=false I'm having a hard time debugging this one. Does anything jump out at anybody? Notes nginx version: nginx/0.7.62 Django svn trunk rev 13013

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• Designing a peer to peer network

  - by Varun

  I am designing a simple peer to peer network. The basic architecture will be as follows: A central server- that keeps track of all the peers. The job of this server is to keep track of all the peers that join the network. Every peer could do things: a. Download a file from it's peer b. Push a file (send a file) to it's peer. Could anybody please tell me what would be the best design for such a system? What would be the problems that i might run into and so on. I am planning to use Java as the programming language to implement. Would it be a good choice? Also, is it necessary that i would need a Linux box to develop the system? or is it fine if i use a Windows machine? Your help will be much appreciated! Thanks!

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• What's your favourite programming language, and its killer feature?

  - by eplawless

  Each language I've used has had its pros and cons, but some features have really shone through as being indispensible, shining examples of how to design a programming language to make programmers happy. I use PHP a lot at work, and the one thing I really miss when moving to other languages is PHP's foreach: foreach($items as $item) //iterate through items by value foreach($items as &$item) //iterate through items by reference foreach($items as $i => $item) //by value, with indices foreach($items as $i => &$item) //by reference, with indices In C#, I'm kind of smitten with the built-in multicast delegate system, as well as the way it handles getters and setters. So what's your favourite/favorite language, and what feature makes it awesome?

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• Where is a Web Development Career fueled by Passion? [closed]

  - by JMC Creative

  Quick Background Since learning basic html 5 years ago, I've become completely obsessed with the technology, the logic, and the thrill of solving problems involved with building websites. I am still stuck at a thoroughly non-programming type job, but would really like to move into the field of web programming/design. I have no educational background in the field (was trained as a fine artist and tutor), but in the past few years have progressed fully self-taught (and self-motivated) from html to css to php, mysql, jquery, and am now building rich web applications. The Question How can I prove to a company that even though I have no education, I have a passion to learn whatever is thrown my way? ...That essentially I would come at every issue with not only knowledge, but with a passionate desire to solve it, whether that means tackling a new language or debugging code for hours at a time? p.s. Sorry for the stupid title.

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• How can I manage command line arguements/variables for a script written in Perl?

  - by Structure

  I am trying to manage numerous arguments that are specified by a user when they execute a command. So far, I have been trying to limit my script design to manage arguments as flags that I can easily manage with Getopt::Long as follows: GetOptions ("a" => \$a, "b" => \$b); In this way I can check to see if a or b were specified and then execute the respective code/functions. However, I now have a case where the user can specify two arguments variables as follows: command -a black -b white This is fine, but I cannot come up with a good way to determine whether -a or -b is specified first. Therefore I do not know whether the argument variable is assigned to $ARGV[0] or $ARGV[1] after I have executed GetOptions ("a" => \$a, "b" => \$b);. How can I tell which variable is associated with -a and which is associated with -b in the example above?

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• What do you tell people your profession is? [closed]

  - by user110296

  My technical title is Member of the Technical Staff, and like you most of you, I design/write code for a living. I can never decide what to answer when someone asks what I do for a living? Software Developer? Software Engineer? [Kernel] Programmer? Computer Scientist? These all seem to have various bad connotations. I guess I like Software Engineer the best, but unfortunately this term has been coopted by people who don't actually code. I made the mistake of taking a 'Software Engineering' class, and realized that I definitely don't want to be associated with people who major in this. Probably this is too subjective, so feel free to community wiki it or whatever, but I think it is a valid question and I would like to hear what others have decided on and their reasoning.

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• How to set variable before callback is called?

  - by user1995327

  I'm trying to design a webpage... I have a function that I call get all info needed for an idividuals home page. A snippet of the codes is: exports.getHomePageData = function(userId, cb) { var pageData = {}; pageData.userFullName = dbUtil.findNameByUserId(userId, function(err){ if (err) cb(err); }); pageData.classes = dbUtil.findUserClassesByUserId(userId, function(err){ if (err) cb(err); }); cb(pageData); } The problem I'm having is the cb(pageData) is being called before I even finish setting the elements. I've seen that people use the async library to solve this but I was wondering if there was any other way for me to do it without needing more modules... Thanks!

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• How do I make the footer stretch vertically downward align to footer.

  - by text

  I am new to web design using tableless and I'm having problem positioning some elements on my page.. Here's the sample html: http://christianruado.comuf.com/sample.html As you can see from the screen shots I want my right div to be vertically stretched down to the same level of my footer and position my bottom element to the lowest part of the right container. #right { float:right; width: 19%; background:#FF3300; margin-left:2px; height: 100%; } #right .bottom { bottom:0; display:block; background-color:#FFCCFF; height:30px; }

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