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  • Database schema for simple stats project

    - by Bubnoff
    Backdrop: I have a file hierarchy of cvs files for multiple locations named by dates they cover ...by month specifically. Each cvs file in the folder is named after the location. eg', folder name: 2010-feb contains: location1.csv location2.csv Each CSV file holds records like this: 2010-06-28, 20:30:00 , 0 2010-06-29, 08:30:00 , 0 2010-06-29, 09:30:00 , 0 2010-06-29, 10:30:00 , 0 2010-06-29, 11:30:00 , 0 meaning of record columns ( column names ): Date, time, # of sessions I have a perl script that pulls the data from this mess and originally I was going to store it as json files, but am thinking a database might be more appropriate long term ...comparing year to year trends ...fun stuff like that. Pt 2 - My question/problem: So I now have a REST service that coughs up json with a test database. My question is [ I suck at db design ], how best to design a database backend for this? I am thinking the following tables would suffice and keep it simple: Location: (PK)location_code, name session: (PK)id, (FK)location_code, month, hour, num_sessions I need to be able to average sessions (plus min and max) for each hour across days of week in addition to days of week in a given month or months. I've been using perl hashes to do this and am trying to decide how best to implement this with a database. Do you think stored procedures should be used? As to the database, depending on info gathered here, it will be postgresql or sqlite. If there is no compelling reason for postgresql I'll stick with sqlite. How and where should I compare the data to hours of operation. I am storing the hours of operation in a yaml file. I currently 'match' the hour in the data to a hash from the yaml to do this. Would a database open simpler methods? I am thinking I would do this comparison as I do now then insert the data. Can be recalled with: SELECT hour, num_sessions FROM session WHERE location_code=LOC1 Since only hours of operation are present, I do not need to worry about it. Should I calculate all results as I do now then store as a stats table for different 'reports'? This, rather than processing on demand? How would this look? Anyway ...I ramble. Thanks for reading! Bubnoff

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  • Simple html page using Bootstrap

    - by Athashri
    I am writing a simple HTML page using the Twitter Bootstrap. But the navbar and links are rendered as normal HTML on the browser. I have referred to multiple sites but the same steps are given everywhere. I am not sure where I am going wrong. Code: <!DOCTYPE HTML> <html> <head> <meta charset="utf-8"> <link rel= "stylesheet" href= "css/bootstrap.css" type="text/css"> <title> Bootstrap example</title> </head> <body> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script> <script src="js/bootstrap.js"></script> <h1>Hello, world!</h1> <div class ="container"> <h1><a href="#">Bootstrap Site</a></h1> <div class="navbar"> <div class="navbar-inner"> <div class="container"> <ul class="nav"> <li class="active"><a href="#">Home</a></li> <li><a href="#">Projects</a></li> <li><a href="#">Services</a></li> <li><a href="#">Downloads</a></li> <li><a href="#">About</a></li> <li><a href="#">Contact</a></li> </ul> </div> </div> </div> </div> </body> </html>

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  • Generate A Simple Read-Only DAL?

    - by David
    I've been looking around for a simple solution to this, trying my best to lean towards something like NHibernate, but so far everything I've found seems to be trying to solve a slightly different problem. Here's what I'm looking at in my current project: We have an IBM iSeries database as a primary repository for a third party software suite used for our core business (a financial institution). Part of what my team does is write applications that report on or key off of a lot of this data in some way. In the past, we've been manually creating ADO .NET connections (we're using .NET 3.5 and Visual Studio 2008, by the way) and manually writing queries, etc. Moving forward, I'd like to simplify the process of getting data from there for the development team. Rather than creating connections and queries and all that each time, I'd much rather a developer be able to simply do something like this: var something = (from t in TableName select t); And, ideally, they'd just get some IQueryable or IEnumerable of generated entities. This would be done inside a new domain core that I'm building where these entities would live and the applications would interface with it through a request/response service layer. A few things to note are: The entities that correspond to the database tables should be generated once and we'd prefer to manually keep them updated over time. That is, if columns/tables are added to the database then we shouldn't have to do anything. (If some are deleted, of course, it will break, but that's fine.) But if we need to use a new column, we should be able to just add it to the necessary class(es) without having to re-gen the whole thing. The whole thing should be SELECT-only. We're not doing a full DAL here because we don't want to be able to break anything in the database (even accidentally). We don't need any kind of mapping between our domain objects and the generated entity types. The domain barely covers a fraction of the data that's in there, most of it we'll never need, and we would rather just create re-usable maps manually over time. I already have a logical separation for the DAL where my "repository" classes return domain objects, I'm just looking for a better alternative to manual ADO to be used inside the repository classes. Any suggestions? It seems like what I'm doing is just enough outside the normal demand for DAL/ORM tools/tutorials online that I haven't been able to find anything. Or maybe I'm just overlooking something obvious?

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  • Simple Form validation failing Backbone

    - by Corey Buchillon
    Im not exactly adept at coding so Im probably missing something, but my view here is failing to refuse submission when one or both of the fields are empty. I have a feeling something isnt connected right to my template for the row and the view of the form Form = Backbone.View.extend({ //form vie el: '.item-form', initialize: function(){ }, events: { 'click #additem': 'addModel' }, addModel: function(itemName, price){ // simple validation before adding to collection if (itemName !="" && price !="" ){ var item = new Item({ itemName: this.$("#item").val(), price: this.$("#price").val()}); items.add(item); $("#message").html("Please wait; the task is being added."); item.save(null, {success: function (item, response,options) { item.id= item.attributes._id.$id; item.attributes.id = item.attributes._id.$id; new ItemsView({collection: items}); $("#message").html(""); } }); this.$("#item").val(''); this.$("#price").val(''); } else { alert('Please fill in both fields'); } } }); and HTML <table class="itemTable"> <thead> <tr> <th>Item</th> <th>Price</th> <th></th> </tr> </thead> <tbody class="tableBody"> <script type="text/template" id="table-row"> <td><%= itemName %></td> <td><%= price %></td> <td><button class="complete">Complete</button> <button class="remove">Remove</button></td> </script> </tbody> </table> <form class="item-form"> <input type="text" name="item" id="item" placeholder="Item"/> <!-- goes to itemName in the template for the body --> <input type="text" name="price" id="price" placeholder="Price" /><!--goes to price in the template for the body --> <button type="button" id="additem">Add</button> </form> <div id="message"></div>

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  • Simple jquery Fade Slideshow fails on certain browsers

    - by cmay
    So I have a simple slideshow on my website which just shows one image then shows another until it reaches the end or the user hits skip in which case it shows index.html. The site is served on apache2 with Django. The slideshow works perfectly on most machines, but certain machines it shows some images twice and other images not at all and the timing is off. I am using jquery 1.4.3. Below is the section of html where I push the image urls from the database to the javascript {% for image in latest_images %} {% thumbnail image.image_file "800x600" crop="center" as im %} <script>FadeImageList.push("{{im.url}}");</script> {% endthumbnail %} {% endfor %} Below is the full javascript file var FadeImageList = []; var fadeDuration = 2000; var fadeImgID = '#slideShow'; var homePageID = '#homePage'; var menuID = '#menu'; var skipFlag = 0; $(document).ready(function(){ $(homePageID).fadeOut(50); PlaySlideshow(FadeImageList); }); var PlaySlideshow = function(FadeImageList){ var newImgSrc = FadeImageList.shift(); $('#skip').click(function(){$('#loader').show();skipFlag = 1;}); if(((typeof(newImgSrc) !== "string") || (skipFlag === 1))){ EndSlideShow(); return; } else{ $(fadeImgID).fadeOut(fadeDuration,function(){ $(fadeImgID).attr('src', newImgSrc); $(fadeImgID).fadeIn(fadeDuration,function(){ PlaySlideshow(FadeImageList); }); }); } }; var EndSlideShow = function(fadeSettings){ $(fadeImgID).fadeOut(400,function(){ $(homePageID).fadeIn(400); $("#skip").fadeOut(400); $('#loader').hide(); }); }; The strange thing is I've had it work and fail on identically version numbered browsers on the same os but on different machines. It consistently either works or fails on a machine. I've had it fail in ie 7,8 firefox 3.6.3 and chrome. I've also had it succeed in ie6,7,8 firefox 3.6.3,3.4.2,3.1 and chrome.

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  • C# A simple Hangman game

    - by Radostin Angelov
    I'm trying to create a simple Hangman game and i have gotten so far, to make it read all words from a text file, but I don't know how to make the code work for every single word. I have another project, working with 3/4 words but with repeating nested if statements. I want to make it as shorter as possible. This is the code i have so far : using System; using System.Linq; class Program { static void Main() { string[] words = System.IO.File.ReadAllLines(@"C:\Users\ADMIN\Desktop\Letters\Letters.txt"); int LengthOfArray = words.Length; Random rnd = new Random(); int random = rnd.Next(1, 3); char[] letters = words[random].ToCharArray(); bool WordIsHidden = true; char hiddenChar = '_'; char GuessedLetter = hiddenChar; var retry = true; while (retry = true) { Console.WriteLine(letters); letters = GuessedLetter.ToString().ToCharArray(); for (int i = 1; i <= LengthOfArray; i++) { Console.Write("{0} ", GuessedLetter); } Console.WriteLine("Enter a letter!"); char letter = char.Parse(Console.ReadLine()); if (words[random].Contains<char>(letter)) { WordIsHidden = false; GuessedLetter = letter; Console.Write(letters); } else { if (WordIsHidden == true) { Console.Write("You guessed wrong!"); } } } } } Also I'm trying to make the game show each letter, the user has guessed on it's corresponding position, but now the letter is one line higher than the rest of the word and it's not in it's right position. Edited: Here is the result : cat ___Enter a letter! a __ aaaEnter a letter! t aa tttEnter a letter! IF anyone have a clue for where does this come from and how can I fix it, any help will be greatly appreciated.

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  • Simple jquery ajax call leaks memory in ie.

    - by Thomas Lane
    I created a web page that makes an ajax call every second. In Internet Explorer 7, it leaks memory badly (20MB in about 15 minutes). The program is very simple. It just runs a javascript function that makes an ajax call. The server returns an empty string, and the javascript does nothing with it. I use setTimout to run the function every second, and I'm using Drip to watch the thing. Here is the source: <html> <head> <script type="text/javascript" src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load('jquery', '1.4.2'); google.load('jqueryui', '1.7.2'); </script> <script type="text/javascript"> setTimeout('testJunk()',1000); function testJunk() { $.ajax({ url: 'http://xxxxxxxxxxxxxx/test', // The url returns an empty string dataType: 'html', success: function(data){} }); setTimeout('testJunk()',1000) } </script> </head> <body> Why is memory usage going up? </body> </html> Anyone have an idea how to plug this leak? I have a real application that updates a large table this way, but left unattended will eat up Gigabytes of memory. Okay, so after some good suggestions, I modified the code to: <html> <head> <script type="text/javascript" src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load('jquery', '1.4.2'); google.load('jqueryui', '1.7.2'); </script> <script type="text/javascript"> setTimeout(testJunk,1000); function testJunk() { $.ajax({ url: 'http://xxxxxxxxxxxxxx/test', // The url returns an empty string dataType: 'html', success: function(data){setTimeout(testJunk,1000)} }); } </script> </head> <body> Why is memory usage going up? </body> </html> It didn't seem to make any difference though. I'm not doing anything with the DOM, and if I comment out the ajax call, the memory leak stops. So it looks like the leak is entirely in the ajax call. Does jquery ajax inherently create some sort of circular reference, and if so, how can I free it? By the way, it doesn't leak in Firefox. Someone suggested running the test in another VM and see if the results are the same. Rather than setting up another VM, I found a laptop that was running XP Home with IE8. It exhibits the same problem. I tried some older versions of jquery and got better results, but the problem didn't go away entirely until I abandoned ajax in jquery and went with more traditional (and ugly) ajax.

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  • migrating simple rails database to mysql

    - by joseph-misiti
    i am interested in creating a rails app with a mysql database. i am new to rails and am just trying to start creating something simple: rails -d mysql MyMoviesSQL cd MyMoviesSQL script/generate scaffold Movies title:string rating:integer rake db:migrate i am seeing the following error: rake aborted! NoMethodError: undefined method `ord' for 0:Fixnum: SET NAMES 'utf8' if i do a trace: ** Invoke db:migrate (first_time) ** Invoke environment (first_time) ** Execute environment ** Execute db:migrate rake aborted! NoMethodError: undefined method ord' for 0:Fixnum: SET NAMES 'utf8' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract_adapter.rb:219:inlog' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:323:in execute' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:599:inconfigure_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:594:in connect' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:203:ininitialize' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:75:in new' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:75:inmysql_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:223:in send' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:223:innew_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:245:in checkout_new_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:188:incheckout' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in loop' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:incheckout' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in synchronize' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:183:incheckout' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:98:in connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:326:inretrieve_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:123:in retrieve_connection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:115:inconnection' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:435:in initialize' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:400:innew' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:400:in up' /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:383:inmigrate' /Library/Ruby/Gems/1.8/gems/rails-2.3.5/lib/tasks/databases.rake:116 /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in call' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:inexecute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:inexecute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in invoke_with_call_chain' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:insynchronize' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in invoke_with_call_chain' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:ininvoke' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in invoke_task' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:intop_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:intop_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in standard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:intop_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:instandard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/bin/rake:31 /usr/bin/rake:19:inload' /usr/bin/rake:19 here are my versions: rails - 2.3.5 ruby - 1.8.6 gem list * LOCAL GEMS * actionmailer (2.3.5, 1.3.6) actionpack (2.3.5, 1.13.6) actionwebservice (1.2.6) activerecord (2.3.5, 1.15.6) activeresource (2.3.5) activesupport (2.3.5, 1.4.4) acts_as_ferret (0.4.1) capistrano (2.0.0) cgi_multipart_eof_fix (2.5.0) daemons (1.0.9) dbi (0.4.3) deprecated (2.0.1) dnssd (0.6.0) fastthread (1.0.1) fcgi (0.8.7) ferret (0.11.4) gem_plugin (0.2.3) highline (1.2.9) hpricot (0.6) libxml-ruby (0.9.5, 0.3.8.4) mongrel (1.1.4) needle (1.3.0) net-sftp (1.1.0) net-ssh (1.1.2) rack (1.0.1) rails (2.3.5) rake (0.8.7, 0.7.3) RedCloth (3.0.4) ruby-openid (1.1.4) ruby-yadis (0.3.4) rubygems-update (1.3.6) rubynode (0.1.3) sqlite3-ruby (1.2.1) termios (0.9.4) also, if i need to add a patch to FixNum, can someone please tell which file to add the patch to. thanks for your help

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  • Javascript Noob Question. Need Help With Simple Script

    - by three3
    Hi everyone, I am new to JavaScript (only a couple of days of reading a book) and I am stuck on this code snippet. I have looked at it over and over again but cannot seem to figure out why it is not working. I am sure it is something really simple that I have just looked over but I really just need a fresh pair of eyes to look at this. The code is supposed to update a placeholder image on a page without the page having to reload. But when I am clicking on the link of an image, it is taking me to the link where the image is located instead of replacing the placeholder image. Here is my HTML code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Image Gallery</title> <script type="text/javascript" src="scripts/showPic.js"></script> </head> <body> <h1>Snapshots</h1> <ul> <li> <a href="images/cat.jpg" onclick="showPic(this); return false;" title="A Cat">Cat</a> </li> <li> <a href="images/night.jpg" onclick="showPic(this); return false;" title="Night">Night</a> </li> <li> <a href="images/coke.jpg" onclick="showPic(this); return false;" title="Coke">Coke</a> </li> <li> <a href="images/sport.jpg" onclick="showPic(this); return false;" title="Sports">Sport</a> </li> <li> <a href="images/mnms.png" onclick="showPic(this); return false;" title="MnM's">MnM's</a> </li> <li> <a href="images/kid.jpg" onclick="showPic(this); return false;" title="A Kid">Kid</a> </li> </ul> <br /> <img id="placeholder" src="images/placeholder.jpg" alt="Place Holder Image" /> </body> </html> And here is the JavaScript function I am using to get this done: <script type="text/javascript"> function showPic(whichpic) { var source = whichpic.getAttribute("href"); var placeholder = document.getElementById("placeholder"); placeholder.setAttribute("src",source); } </script> Any help is greatly appreciated and thanks in advance for the help.

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  • simple C++ hash_set example

    - by celil
    I am new to C++ and STL. I am stuck with the following simple example of a hash set storing custom data structures: #include <iostream> #include <ext/hash_set> using namespace std; using namespace __gnu_cxx; struct trip { int trip_id; int delta_n; int delta_secs; trip(int trip_id, int delta_n, int delta_secs){ this->trip_id = trip_id; this->delta_n = delta_n; this->delta_secs = delta_secs; } }; struct hash_trip { size_t operator()(const trip t) { hash<int> H; return H(t.trip_id); } }; struct eq_trip { bool operator()(const trip t1, const trip t2) { return (t1.trip_id==t2.trip_id) && (t1.delta_n==t2.delta_n) && (t1.delta_secs==t2.delta_secs); } }; int main() { hash_set<trip, hash_trip, eq_trip> trips; trip t = trip(3,2,-1); trip t1 = trip(3,2,0); trips.insert(t); } when I try to compile it, I get the following error message: /usr/include/c++/4.2.1/ext/hashtable.h: In member function ‘size_t __gnu_cxx::hashtable<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc>::_M_bkt_num_key(const _Key&, size_t) const [with _Val = trip, _Key = trip, _HashFcn = hash_trip, _ExtractKey = std::_Identity<trip>, _EqualKey = eq_trip, _Alloc = std::allocator<trip>]’: /usr/include/c++/4.2.1/ext/hashtable.h:599: instantiated from ‘size_t __gnu_cxx::hashtable<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc>::_M_bkt_num(const _Val&, size_t) const [with _Val = trip, _Key = trip, _HashFcn = hash_trip, _ExtractKey = std::_Identity<trip>, _EqualKey = eq_trip, _Alloc = std::allocator<trip>]’ /usr/include/c++/4.2.1/ext/hashtable.h:1006: instantiated from ‘void __gnu_cxx::hashtable<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc>::resize(size_t) [with _Val = trip, _Key = trip, _HashFcn = hash_trip, _ExtractKey = std::_Identity<trip>, _EqualKey = eq_trip, _Alloc = std::allocator<trip>]’ /usr/include/c++/4.2.1/ext/hashtable.h:437: instantiated from ‘std::pair<__gnu_cxx::_Hashtable_iterator<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc>, bool> __gnu_cxx::hashtable<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc>::insert_unique(const _Val&) [with _Val = trip, _Key = trip, _HashFcn = hash_trip, _ExtractKey = std::_Identity<trip>, _EqualKey = eq_trip, _Alloc = std::allocator<trip>]’ /usr/include/c++/4.2.1/ext/hash_set:197: instantiated from ‘std::pair<typename __gnu_cxx::hashtable<_Value, _Value, _HashFcn, std::_Identity<_Value>, _EqualKey, _Alloc>::const_iterator, bool> __gnu_cxx::hash_set<_Value, _HashFcn, _EqualKey, _Alloc>::insert(const typename __gnu_cxx::hashtable<_Value, _Value, _HashFcn, std::_Identity<_Value>, _EqualKey, _Alloc>::value_type&) [with _Value = trip, _HashFcn = hash_trip, _EqualKey = eq_trip, _Alloc = std::allocator<trip>]’ try.cpp:45: instantiated from here /usr/include/c++/4.2.1/ext/hashtable.h:595: error: passing ‘const hash_trip’ as ‘this’ argument of ‘size_t hash_trip::operator()(trip)’ discards qualifiers What am I doing wrong?

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  • Simple Convention Automapper for two-way Mapping (Entities to/from ViewModels)

    - by Omu
    UPDATE: this stuff has evolved into a nice project, see it at http://valueinjecter.codeplex.com check this out, I just wrote a simple automapper, it takes the value from the property with the same name and type of one object and puts it into another, and you can add exceptions (ifs, switch) for each type you may need so tell me what do you think about it ? I did it so I could do something like this: Product –> ProductDTO ProductDTO –> Product that's how it begun: I use the "object" type in my Inputs/Dto/ViewModels for DropDowns because I send to the html a IEnumerable<SelectListItem> and I receive a string array of selected keys back public void Map(object a, object b) { var pp = a.GetType().GetProperties(); foreach (var pa in pp) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { //no such property in b continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } } } UPDATE: the real usage: the Build methods (Input = Dto): public static TI BuildInput<TI, T>(this T entity) where TI: class, new() { var input = new TI(); input = Map(entity, input) as TI; return input; } public static T BuildEntity<T, TI, TR>(this TI input) where T : class, new() where TR : IBaseAdvanceService<T> { var id = (long)input.GetType().GetProperty("Id").GetValue(input, null); var entity = LocatorConfigurator.Resolve<TR>().Get(id) ?? new T(); entity = Map(input, entity) as T; return entity; } public static TI RebuildInput<T, TI, TR>(this TI input) where T: class, new() where TR : IBaseAdvanceService<T> where TI : class, new() { return input.BuildEntity<T, TI, TR>().BuildInput<TI, T>(); } in the controller: public ActionResult Create() { return View(new Organisation().BuildInput<OrganisationInput, Organisation>()); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(OrganisationInput o) { if (!ModelState.IsValid) { return View(o.RebuildInput<Organisation,OrganisationInput, IOrganisationService>()); } organisationService.SaveOrUpdate(o.BuildEntity<Organisation, OrganisationInput, IOrganisationService>()); return RedirectToAction("Index"); } The real Map method public static object Map(object a, object b) { var lookups = GetLookups(); var propertyInfos = a.GetType().GetProperties(); foreach (var pa in propertyInfos) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(LookupItem)) { pb.SetValue(b, (pa.GetValue(a, null) as LookupItem).GetSelectList(pa.Name), null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(object)) { pb.SetValue(b, pa.GetValue(a, null).ReadSelectItemValue(), null); } else if (pa.PropertyType == typeof(long) && pb.PropertyType == typeof(Organisation)) { pb.SetValue(b, pa.GetValue<long>(a).ReadOrganisationId(), null); } else if (pa.PropertyType == typeof(Organisation) && pb.PropertyType == typeof(long)) { pb.SetValue(b, pa.GetValue<Organisation>(a).Id, null); } } return b; }

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  • Need Help With This Simple Script (JavaScript Noob Question)

    - by three3
    Hi everyone, I am new to JavaScript (only a couple of days of reading a book) and I am stuck on this code snippet. I have looked at it over and over again but cannot seem to figure out why it is not working. I am sure it is something really simple that I have just looked over but I really just need a fresh pair of eyes to look at this. The code is supposed to update a placeholder image on a page without the page having to reload. But when I am clicking on the link of an image, it is taking me to the link where the image is located instead of replacing the placeholder image. Here is my HTML code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Image Gallery</title> <script type="text/javascript" src="scripts/showPic.js"></script> </head> <body> <h1>Snapshots</h1> <ul> <li> <a href="images/cat.jpg" onclick="showPic(this); return false;" title="A Cat">Cat</a> </li> <li> <a href="images/night.jpg" onclick="showPic(this); return false;" title="Night">Night</a> </li> <li> <a href="images/coke.jpg" onclick="showPic(this); return false;" title="Coke">Coke</a> </li> <li> <a href="images/sport.jpg" onclick="showPic(this); return false;" title="Sports">Sport</a> </li> <li> <a href="images/mnms.png" onclick="showPic(this); return false;" title="MnM's">MnM's</a> </li> <li> <a href="images/kid.jpg" onclick="showPic(this); return false;" title="A Kid">Kid</a> </li> </ul> <br /> <img src="images/placeholder.jpg" title="Place Holder Image"> </body> </html> And here is the JavaScript function I am using to get this done: <script type="text/javascript"> function showPic(whichpic) { var source = whichpic.getAttribute("href"); var placeholder = document.getElementById("placeholder"); placeholder.setAttribute("src",source); } </script> Any help is greatly appreciated and thanks in advance for the help.

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  • Simple show/hide jQuery troubles

    - by Banderdash
    Okay, I feel like a bit of a 800 pound gorilla trying to thread a needle when it comes to jQuery. I need a script that will preform a simple show/hide (preferably with a nice sliding in and out) on a list. My markup looks like this: <div id="themes"> <h2>Research Themes</h2> <ul> <li class="tier_1"><a href="">Learn about our approach to the <strong>environment</strong></a> <ul class="tier_2 hide"> <li><a href=""><em>How we are tying this all together</em></a></li> <li><a href=""><strong>Project:</strong> Solor Powered Biofactories</a></li> <li><a href=""><strong>Project:</strong> Cleaning Water with Nature</a></li> <li><a href=""><strong>Project:</strong> Higher Efficiency Solar Technology</a></li> </ul> </li> <li class="tier_1"><a href="">Learn about our approach to <strong>human health</strong></a> <ul class="tier_2 hide"> <li><a href="">Project name numero uno goes here</a></li> <li><a href="">Project name numero dos goes here</a></li> <li><a href="">Project name numero tres goes here</a></li> </ul> </li> <li class="tier_1"><a href="">Learn about our approach to <strong>national defense</strong></a> <ul class="tier_2 hide"> <li><a href="">Project name numero uno goes here</a></li> <li><a href="">Project name numero dos goes here</a></li> <li><a href="">Project name numero tres goes here</a></li> </ul> </li> </ul> </div><!-- // end themes --> You can see that each nested ul has a class of "tier_2" and "hide". Ideally when the li they are nested within ("li.tier_1") is clicked it's child ul will have the hide class removed and the li's contained within will slideout, but at the same time should check all the other ul.tier_2's and be sure they get a hide class--so only one theme can be expanded at a time. I set up a sandbox to try some things: http://jsbin.com/odete/3 My JS looks like this: $(function(){ $(".tier_1 a").each(function(i,o){ $(this).click(function(e){ e.preventDefault(); $(this).addClass("show").siblings("ul").removeClass("show"); $("ul.tier_2:eq("+i+")").show().siblings("ul.tier_2").hide(); }); }); }); Totally a dumb way to do this, I am sure. But I based it off another script and it does work "a little bit" as you can see in the sandbox. If one of you mean hands at jQuery might be so inclined to take a peek I'd be very grateful. If you could also advise on how to have the transitions slideIn and Out that would also be fantastic!

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  • Qwt plot not working , simple plot curve not appeat

    - by user1629213
    I followed the example of simple plot in qwt examples to plot a curve. The axis and the graph appear in the Qt main window user interface but the curve not. I assigned values to fit the curve but the curve not appear. Any suggestions and help how to solve the problem? Here is my code MainWindow::MainWindow( int argc, char** argv, QWidget *parent ) : QMainWindow( parent ) , qnode( argc,argv ) { ui.setupUi( this ); // Calling this incidentally connects all ui's triggers to on_...() callbacks in this class. QObject::connect( ui.actionAbout_Qt, SIGNAL( triggered( bool )), qApp, SLOT( aboutQt( ))); // qApp is a global variable for the application ReadSettings( ); setWindowIcon( QIcon( ":/images/icon.png" )); ui.tab_manager->setCurrentIndex( 0 ); // ensure the first tab is showing - qt-designer should have this already hardwired, but often loses it (settings?). QObject::connect( &qnode, SIGNAL( rosShutdown( )), this, SLOT( close( ))); /********************* ** Logging **********************/ ui.view_logging->setModel( qnode.loggingModel( )); QObject::connect( &qnode, SIGNAL( loggingUpdated( )), this, SLOT( updateLoggingView( ))); QObject::connect( &qnode, SIGNAL( graphReceived( )), this, SLOT( onGraphReceived( ))); QObject::connect( &qnode, SIGNAL( parameterReceived( )), this, SLOT( onParameterReceived( ))); /********************* ** Auto Start **********************/ if ( ui.checkbox_remember_settings->isChecked( )) { on_button_connect_clicked( true ); } ui.parameters->setAttribute( Qt::WA_NoMousePropagation ); ui.parameters->setAttribute( Qt::WA_OpaquePaintEvent ); ui.plotgraph->setAttribute( Qt::WA_NoMousePropagation ); ui.plotgraph->setAttribute( Qt::WA_OpaquePaintEvent ); p_plot = new QwtPlot(ui.plotgraph); p_plot->setTitle( "Plot LinVel" ); p_plot->setCanvasBackground( Qt::white ); // Axis p_plot->setAxisTitle( QwtPlot::xBottom, "Time(sec)" ); p_plot->setAxisTitle( QwtPlot::yLeft, "Linear Velocity (m/sec)" ); p_plot->setAxisScale( QwtPlot::yLeft, 0.0, 10.0 ); p_plot->setAxisScale( QwtPlot::xBottom, 0.0, 50.0 ); p_plot->insertLegend( new QwtLegend() ); //samplingThread.start(); QwtPlotGrid *grid = new QwtPlotGrid(); grid->attach( p_plot ); curve = new QwtPlotCurve(); curve->setTitle( "Linear velocity" ); // Set curve styles curve->setPen( Qt::blue, 4 ), curve->setRenderHint( QwtPlotItem::RenderAntialiased, true ); QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse, QBrush( Qt::yellow), QPen( Qt::red, 2 ), QSize( 8, 8 ) ); curve->setSymbol( symbol); // Assign values to the curve //curve->setSamples(ui.plotgraph.get_linv_g());//yaw_g,trav_g,wall_g; curve->attach( p_plot ); p_plot->resize( 600, 400 ); p_plot->show(); void MainWindow::onGraphReceived( ) { { QMutexLocker locker( &qnode.m_mutex ); } } void MainWindow::onParameterReceived( ) { { QMutexLocker locker( &qnode.m_mutex ); std::vector<double> p_ = qnode.get_parameters(); std::cout << p_[0]<<" "<<p_[1]<<" "<<p_[2]<<" "<<p_[3]<<" "<<p_[4] << std::endl; } } Any help?

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  • Error Loading Simple XML

    - by Rooneyl
    I have an xml document (generated from msword 2010), which I am trying to process using simple xml. Sample of xml: <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <w:document xmlns:wpc="http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:m="http://schemas.openxmlformats.org/officeDocument/2006/math" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:wp14="http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing" xmlns:wp="http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing" xmlns:w10="urn:schemas-microsoft-com:office:word" xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" xmlns:w14="http://schemas.microsoft.com/office/word/2010/wordml" xmlns:wpg="http://schemas.microsoft.com/office/word/2010/wordprocessingGroup" xmlns:wpi="http://schemas.microsoft.com/office/word/2010/wordprocessingInk" xmlns:wne="http://schemas.microsoft.com/office/word/2006/wordml" xmlns:wps="http://schemas.microsoft.com/office/word/2010/wordprocessingShape" mc:Ignorable="w14 wp14"> <w:body> <w:p w:rsidR="005B1098" w:rsidRDefault="005B1098"/> <w:p w:rsidR="00F254A4" w:rsidRDefault="00F254A4"/> <w:p w:rsidR="00F254A4" w:rsidRPr="008475A1" w:rsidRDefault="00C15492" w:rsidP="008475A1"> <w:pPr> <w:jc w:val="center"/> <w:rPr> <w:b/> <w:sz w:val="44"/> <w:szCs w:val="44"/> </w:rPr> </w:pPr> <w:r w:rsidRPr="008475A1"> <w:rPr> <w:b/> <w:sz w:val="44"/> <w:szCs w:val="44"/> </w:rPr> <w:t>Test file</w:t> </w:r> </w:p> <w:p w:rsidR="00C15492" w:rsidRPr="008475A1" w:rsidRDefault="00C15492" w:rsidP="008475A1"> <w:pPr> <w:jc w:val="center"/> <w:rPr> <w:sz w:val="20"/> <w:szCs w:val="20"/> </w:rPr> </w:pPr> <w:r w:rsidRPr="008475A1"> <w:rPr> <w:sz w:val="20"/> <w:szCs w:val="20"/> </w:rPr> <w:t>another paragraph</w:t> </w:r> </w:p> </w:body> </w:document> I am trying to open it using: if(!$simple_xml = simplexml_load_file($content)){ trigger_error('Error reading XML file',E_USER_ERROR); } else { echo 'loaded'; } And get the error: Message: simplexml_load_file(): I/O warning : failed to load external entity " Test file another paragraph " Any ideas?

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  • Problem when trying to use simple Shaders + VBOs

    - by Mr.Gando
    Hello I'm trying to convert the following functions to a VBO based function for learning purposes, it displays a static texture on screen. I'm using OpenGL ES 2.0 with shaders on the iPhone (should be almost the same than regular OpenGL in this case), this is what I got working: //Works! - (void) drawAtPoint:(CGPoint)point depth:(CGFloat)depth { GLfloat coordinates[] = { 0, 1, 1, 1, 0, 0, 1, 0 }; GLfloat width = (GLfloat)_width * _maxS, height = (GLfloat)_height * _maxT; GLfloat vertices[] = { -width / 2 + point.x, -height / 2 + point.y, width / 2 + point.x, -height / 2 + point.y, -width / 2 + point.x, height / 2 + point.y, width / 2 + point.x, height / 2 + point.y, }; glBindTexture(GL_TEXTURE_2D, _name); //Attrib position and attrib_tex coord are handles for the shader attributes glVertexAttribPointer(ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, vertices); glEnableVertexAttribArray(ATTRIB_POSITION); glVertexAttribPointer(ATTRIB_TEXCOORD, 2, GL_FLOAT, GL_FALSE, 0, coordinates); glEnableVertexAttribArray(ATTRIB_TEXCOORD); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); } I tried to do this to convert to a VBO however I don't see anything displaying on-screen with this version: //Doesn't display anything - (void) drawAtPoint:(CGPoint)point depth:(CGFloat)depth { GLfloat width = (GLfloat)_width * _maxS, height = (GLfloat)_height * _maxT; GLfloat position[] = { -width / 2 + point.x, -height / 2 + point.y, width / 2 + point.x, -height / 2 + point.y, -width / 2 + point.x, height / 2 + point.y, width / 2 + point.x, height / 2 + point.y, }; //Texture on-screen position ( each vertex is x,y in on-screen coords ) GLfloat coordinates[] = { 0, 1, 1, 1, 0, 0, 1, 0 }; // Texture coords from 0 to 1 glBindVertexArrayOES(vao); glGenVertexArraysOES(1, &vao); glGenBuffers(2, vbo); //Buffer 1 glBindBuffer(GL_ARRAY_BUFFER, vbo[0]); glBufferData(GL_ARRAY_BUFFER, 8 * sizeof(GLfloat), position, GL_STATIC_DRAW); glEnableVertexAttribArray(ATTRIB_POSITION); glVertexAttribPointer(ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, position); //Buffer 2 glBindBuffer(GL_ARRAY_BUFFER, vbo[1]); glBufferData(GL_ARRAY_BUFFER, 8 * sizeof(GLfloat), coordinates, GL_DYNAMIC_DRAW); glEnableVertexAttribArray(ATTRIB_TEXCOORD); glVertexAttribPointer(ATTRIB_TEXCOORD, 2, GL_FLOAT, GL_FALSE, 0, coordinates); //Draw glBindVertexArrayOES(vao); glBindTexture(GL_TEXTURE_2D, _name); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); } In both cases I'm using this simple Vertex Shader //Vertex Shader attribute vec2 position;//Bound to ATTRIB_POSITION attribute vec4 color; attribute vec2 texcoord;//Bound to ATTRIB_TEXCOORD varying vec2 texcoordVarying; uniform mat4 mvp; void main() { //You CAN'T use transpose before in glUniformMatrix4fv so... here it goes. gl_Position = mvp * vec4(position.x, position.y, 0.0, 1.0); texcoordVarying = texcoord; } The gl_Position is equal to product of mvp * vec4 because I'm simulating glOrthof in 2D with that mvp And this Fragment Shader //Fragment Shader uniform sampler2D sampler; varying mediump vec2 texcoordVarying; void main() { gl_FragColor = texture2D(sampler, texcoordVarying); } I really need help with this, maybe my shaders are wrong for the second case ? thanks in advance.

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  • Help with simple linux shell implementation

    - by nunos
    I am implementing a simple version of a linux shell in c. I have succesfully written the parser, but I am having some trouble forking out the child process. However, I think the problem is due to arrays, pointers and such, because just started C with this project and am not still very knowledgable with them. I am getting a segmentation fault and don't know where from. Any help is greatly appreciated. #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/wait.h> #include <sys/types.h> #define MAX_COMMAND_LENGTH 250 #define MAX_ARG_LENGTH 250 typedef enum {false, true} bool; typedef struct { char **arg; char *infile; char *outfile; int background; } Command_Info; int parse_cmd(char *cmd_line, Command_Info *cmd_info) { char *arg; char *args[MAX_ARG_LENGTH]; int i = 0; arg = strtok(cmd_line, " "); while (arg != NULL) { args[i] = arg; arg = strtok(NULL, " "); i++; } int num_elems = i; if (num_elems == 0) return -1; cmd_info->infile = NULL; cmd_info->outfile = NULL; cmd_info->background = 0; int iarg = 0; for (i = 0; i < num_elems-1; i++) { if (!strcmp(args[i], "<")) { if (args[i+1] != NULL) cmd_info->infile = args[++i]; else return -1; } else if (!strcmp(args[i], ">")) { if (args[i+1] != NULL) cmd_info->outfile = args[++i]; else return -1; } else cmd_info->arg[iarg++] = args[i]; } if (!strcmp(args[i], "&")) cmd_info->background = true; else cmd_info->arg[iarg++] = args[i]; cmd_info->arg[iarg] = NULL; return 0; } void print_cmd(Command_Info *cmd_info) { int i; for (i = 0; cmd_info->arg[i] != NULL; i++) printf("arg[%d]=\"%s\"\n", i, cmd_info->arg[i]); printf("arg[%d]=\"%s\"\n", i, cmd_info->arg[i]); printf("infile=\"%s\"\n", cmd_info->infile); printf("outfile=\"%s\"\n", cmd_info->outfile); printf("background=\"%d\"\n", cmd_info->background); } void get_cmd(char* str) { fgets(str, MAX_COMMAND_LENGTH, stdin); str[strlen(str)-1] = '\0'; //apaga o '\n' do fim } pid_t exec_simple(Command_Info *cmd_info) { pid_t pid = fork(); if (pid < 0) { perror("Fork Error"); return -1; } if (pid == 0) { execvp(cmd_info->arg[0], cmd_info->arg); perror(cmd_info->arg[0]); exit(1); } return pid; } int main(int argc, char* argv[]) { while (true) { char cmd_line[MAX_COMMAND_LENGTH]; Command_Info cmd_info; printf(">>> "); get_cmd(cmd_line); if ( (parse_cmd(cmd_line, &cmd_info) == -1) ) return -1; parse_cmd(cmd_line, &cmd_info); if (!strcmp(cmd_info.arg[0], "exit")) exit(0); pid_t pid = exec_simple(&cmd_info); waitpid(pid, NULL, 0); } return 0; } Thanks.

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  • Simple Constructor With Initializer List? - C++

    - by Alex
    Hi all, below I've included my h file, and my problem is that the compiler is not liking my simple exception class's constructor's with initializer lists. It also is saying that string is undeclared identifier, even though I have #include <string> at the top of the h file. Do you see something I am doing wrong? For further explanation, this is one of my domain classes that I'm integrating into a wxWidgets GUI application on Windows. Thanks! Time.h #pragma once #include <string> #include <iostream> // global constants for use in calculation const int HOURS_TO_MINUTES = 60; const int MINUTES_TO_HOURS = 100; class Time { public: // default Time class constructor // initializes all vars to default values Time(void); // ComputeEndTime computes the new delivery end time // params - none // preconditions - vars will be error-free // postconditions - the correct end time will be returned as an int // returns an int int ComputeEndTime(); // GetStartTime is the getter for var startTime // params - none // returns an int int GetStartTime() { return startTime; } // GetEndTime is the getter for var endTime // params - none // returns an int int GetEndTime() { return endTime; } // GetTimeDiff is the getter for var timeDifference // params - none // returns a double double GetTimeDiff() { return timeDifference; } // SetStartTime is the setter for var startTime // params - an int // returns void void SetStartTime(int s) { startTime = s; } // SetEndTime is the setter for var endTime // params - an int // returns void void SetEndTime(int e) { endTime = e; } // SetTimeDiff is the setter for var timeDifference // params - a double // returns void void SetTimeDiff(double t) { timeDifference = t; } // destructor for Time class ~Time(void); private: int startTime; int endTime; double timeDifference; }; class HourOutOfRangeException { public: // param constructor // initializes message to passed paramater // preconditions - param will be a string // postconditions - message will be initialized // params a string // no return type HourOutOfRangeException(string pMessage) : message(pMessage) {} // GetMessage is getter for var message // params none // preconditions - none // postconditions - none // returns string string GetMessage() { return message; } // destructor ~HourOutOfRangeException() {} private: string message; }; class MinuteOutOfRangeException { public: // param constructor // initializes message to passed paramater // preconditions - param will be a string // postconditions - message will be initialized // params a string // no return type MinuteOutOfRangeException(string pMessage) : message(pMessage) {} // GetMessage is getter for var message // params none // preconditions - none // postconditions - none // returns string string GetMessage() { return message; } // destructor ~MinuteOutOfRangeException() {} private: string message; }; class PercentageOutOfRangeException { public: // param constructor // initializes message to passed paramater // preconditions - param will be a string // postconditions - message will be initialized // params a string // no return type PercentageOutOfRangeException(string pMessage) : message(pMessage) {} // GetMessage is getter for var message // params none // preconditions - none // postconditions - none // returns string string GetMessage() { return message; } // destructor ~PercentageOutOfRangeException() {} private: string message; }; class StartEndException { public: // param constructor // initializes message to passed paramater // preconditions - param will be a string // postconditions - message will be initialized // params a string // no return type StartEndException(string pMessage) : message(pMessage) {} // GetMessage is getter for var message // params none // preconditions - none // postconditions - none // returns string string GetMessage() { return message; } // destructor ~StartEndException() {} private: string message; };

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  • Very simple shopping cart, remove button

    - by Kynian
    Im writing sales software that will be walking through a set of pages and on certain pages there are items listed to sell and when you click buy it basically just passes a hidden variable to the next page to be set as a session variable, and then when you get to the end it call gets reported to a database. However my employer wanted me to include a shopping cart, and this shopping cart should display the item name, sku, and price of whatever you're buying, as well as a remove button so the person doing the script doesnt need to go back through the entire thing to remove one item. At the moment I have the cart set to display everything, which was fairly simple. but I cant figure out how to get the remove button to work. Here is the code for the shopping cart: $total = 0; //TEST CODE: $_SESSION['itemname-addon'] = "Test addon"; $_SESSION ['price-addon'] = 10.00; $_SESSION ['sku-addon'] = "1234h"; $_SESSION['itemname-addon1'] = "Test addon1"; $_SESSION ['price-addon1'] = 99.90; $_SESSION ['sku-addon1'] = "1111"; $_SESSION['itemname-addon2'] = "Test addon2"; $_SESSION ['price-addon2'] = 19.10; $_SESSION ['sku-addon2'] = "123"; //end test code $items = Array ( "0"=> Array ( "name" => $_SESSION['itemname-mo'], "price" => $_SESSION ['price-mo'], "sku" => $_SESSION ['sku-mo'] ), "1" => Array ( "name" => $_SESSION['itemname-addon'], "price" => $_SESSION ['price-addon'], "sku" => $_SESSION ['sku-addon'] ), "2" => Array ( "name" => $_SESSION['itemname-addon1'], "price" => $_SESSION ['price-addon1'], "sku" => $_SESSION ['sku-addon1'] ), "3" => Array ( "name" => $_SESSION['itemname-addon2'], "price" => $_SESSION ['price-addon2'], "sku" => $_SESSION ['sku-addon2'] ) ); $a_length = count($items); for($x = 0; $x<$a_length; $x++){ $total +=$items[$x]['price']; } $formattedtotal = number_format($total,2,'.',''); for($i = 0; $i < $a_length; $i++){ $name = $items[$i]['name']; $price = $items[$i]['price']; $sku = $items[$i]['sku']; displaycart($name,$price,$sku); } echo "<br /> <b>Sub Total:</b> $$formattedtotal"; function displaycart($name,$price,$sku){ if($name != null || $price != null || $sku != null){ if ($name == "no sale" || $price == "no sale" || $sku == "no sale"){ echo ""; } else{ $formattedprice = number_format($price,2,'.',''); echo "$name: $$formattedprice ($sku)"; echo "<form action=\"\" method=\"post\">"; echo "<button type=\"submit\" />Remove</button><br />"; echo "</form>"; } } } So at this point Im not sure where to go from here for the remove button. Any suggestions would be appreciated.

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  • How can I make the storage of C++ lambda objects more efficient?

    - by Peter Ruderman
    I've been thinking about storing C++ lambda's lately. The standard advice you see on the Internet is to store the lambda in a std::function object. However, none of this advice ever considers the storage implications. It occurred to me that there must be some seriously black voodoo going on behind the scenes to make this work. Consider the following class that stores an integer value: class Simple { public: Simple( int value ) { puts( "Constructing simple!" ); this->value = value; } Simple( const Simple& rhs ) { puts( "Copying simple!" ); this->value = rhs.value; } Simple( Simple&& rhs ) { puts( "Moving simple!" ); this->value = rhs.value; } ~Simple() { puts( "Destroying simple!" ); } int Get() const { return this->value; } private: int value; }; Now, consider this simple program: int main() { Simple test( 5 ); std::function<int ()> f = [test] () { return test.Get(); }; printf( "%d\n", f() ); } This is the output I would hope to see from this program: Constructing simple! Copying simple! Moving simple! Destroying simple! 5 Destroying simple! Destroying simple! First, we create the value test. We create a local copy on the stack for the temporary lambda object. We then move the temporary lambda object into memory allocated by std::function. We destroy the temporary lambda. We print our output. We destroy the std::function. And finally, we destroy the test object. Needless to say, this is not what I see. When I compile this on Visual C++ 2010 (release or debug mode), I get this output: Constructing simple! Copying simple! Copying simple! Copying simple! Copying simple! Destroying simple! Destroying simple! Destroying simple! 5 Destroying simple! Destroying simple! Holy crap that's inefficient! Not only did the compiler fail to use my move constructor, but it generated and destroyed two apparently superfluous copies of the lambda during the assignment. So, here finally are the questions: (1) Is all this copying really necessary? (2) Is there some way to coerce the compiler into generating better code? Thanks for reading!

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  • Simple syntax error still eluding me.

    - by melee
    Here is the header for a class I started: #ifndef CANVAS_ #define CANVAS_ #include <iostream> #include <iomanip> #include <string> #include <stack> class Canvas { public: Canvas(); void Paint(int R, int C, char Color); const int Nrow; const int Ncol; string Title; int image[][100]; stack<int> path; struct PixelCoordinates { unsigned int r; unsigned int c; } position; Canvas operator<< (const Canvas& One ); Canvas operator>>( Canvas& One ); }; /*----------------------------------------------------------------------------- Name: operator<< Purpose: Put a Canvas into an output stream -----------------------------------------------------------------------------*/ ostream& operator<<( ostream& Out, const Canvas& One ) { Out << One.Title << endl; Out << "Rows: " << One.Nrow << " Columns: " << One.Ncol << endl; int i,j; for( i=0; i<One.Nrow; i++) { cout<<"\n\n\n"; cout<< " COLUMN\n"; cout<< " 1 2 3"; for(i=0;i<One.Nrow;i++) { cout<<"\nROW "<<i+1; for(j=0;j<One.Ncol;j++) cout<< One.image[i][j]; } } return Out; } /*----------------------------------------------------------------------------- Name: operator>> Purpose: Get a Canvas from an input stream -----------------------------------------------------------------------------*/ istream& operator>>( istream& In, Canvas& One ) { // string Line; // int Place = 0; // { // In >> Line; // if (In.good()) // { // One.image[Place][0] = Line; // Place++; // } // return In; #endif Here is my implementation file for class Canvas: using namespace std; #include <iostream> #include <iomanip> #include <string> #include <stack> #include "proj05.canvas.h" //----------------Constructor----------------// Canvas::Canvas() { Title = ""; Nrow = 0; Ncol = 0; image[][100] = {}; position.r = 0; position.c = 0; } //-------------------Paint------------------// void Canvas::Paint(int R, int C, char Color) { cout << "Paint to be implemented" << endl; } And the errors I'm getting are these: proj05.canvas.cpp: In function 'std::istream& operator>>(std::istream&, Canvas&)': proj05.canvas.cpp:11: error: expected `;' before '{' token proj05.canvas.cpp:24: error: expected `}' at end of input From my limited experience, they look like simple syntax errors but for the life of me, I cannot see what I am missing. I know putting a ; at the end of Canvas::Canvas() is wrong but that seems to be what it expects. Could someone please clarify for me? (Also, I know much of the code for the << and operator definitions look terrible, but unless that is the specific reason for the error please do not address it. This is a draft :) )

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  • Simple prime number program - Weird issue with threads C#

    - by Para
    Hi! This is my code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; namespace FirePrime { class Program { static bool[] ThreadsFinished; static bool[] nums; static bool AllThreadsFinished() { bool allThreadsFinished = false; foreach (var threadFinished in ThreadsFinished) { allThreadsFinished &= threadFinished; } return allThreadsFinished; } static bool isPrime(int n) { if (n < 2) { return false; } if (n == 2) { return true; } if (n % 2 == 0) { return false; } int d = 3; while (d * d <= n) { if (n % d == 0) { return false; } d += 2; } return true; } static void MarkPrimes(int startNumber,int stopNumber,int ThreadNr) { for (int j = startNumber; j < stopNumber; j++) nums[j] = isPrime(j); lock (typeof(Program)) { ThreadsFinished[ThreadNr] = true; } } static void Main(string[] args) { int nrNums = 100; int nrThreads = 10; //var threadStartNums = new List<int>(); ThreadsFinished = new bool[nrThreads]; nums = new bool[nrNums]; //var nums = new List<bool>(); nums[0] = false; nums[1] = false; for(int i=2;i<nrNums;i++) nums[i] = true; int interval = (int)(nrNums / nrThreads); //threadStartNums.Add(2); //int aux = firstStartNum; //int i = 2; //while (aux < interval) //{ // aux = interval*i; // i=i+1; // threadStartNums.Add(aux); //} int startNum = 0; for (int i = 0; i < nrThreads; i++) { var _thread = new System.Threading.Thread(() => MarkPrimes(startNum, Math.Min(startNum + interval, nrNums), i)); startNum = startNum + interval; //set the thread to run in the background _thread.IsBackground = true; //start our thread _thread.Start(); } while (!AllThreadsFinished()) { Thread.Sleep(1); } for (int i = 0; i < nrNums; i++) if(nums[i]) Console.WriteLine(i); } } } This should be a pretty simple program that is supposed to find and output the first nrNums prime numbers using nrThreads threads working in parallel. So, I just split nrNums into nrThreads equal chunks (well, the last one won't be equal; if nrThreads doesn't divide by nrNums, it will also contain the remainder, of course). I start nrThreads threads. They all test each number in their respective chunk and see if it is prime or not; they mark everything out in a bool array that keeps a tab on all the primes. The threads all turn a specific element in another boolean array ThreadsFinished to true when they finish. Now the weird part begins: The threads never all end. If I debug, I find that ThreadNr is not what I assign to it in the loop but another value. I guess this is normal since the threads execute afterwards and the counter (the variable i) is already increased by then but I cannot understand how to make the code be right. Can anyone help? Thank you in advance. P.S.: I know the algorithm is not very efficient; I am aiming at a solution using the sieve of Eratosthenes also with x given threads. But for now I can't even get this one to work and I haven't found any examples of any implementations of that algorithm anywhere in a language that I can understand.

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  • Simple Adapter error

    - by Rahul Varma
    Hi, I have the following errors when i try to access the simple adapter from my program... Plz can anyone help me solving the error... Desperate to get it done.... android.widget.SimpleAdapter.getCount(SimpleAdapter.java:95) android.widget.ListView.setAdapter(ListView.java:431) com.stellent.gorinka.MusicListActivity.list(MusicListActivity.java:76) com.stellent.gorinka.MusicListActivity$1.run(MusicListActivity.java:67) android.os.Handler.handleCallback(Handler.java:587) android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:123) android.os.Handler.handleCallback(Handler.java:587) android.os.Handler.dispatchMessage(Handler.java:92) android.os.Looper.loop(Looper.java:123) Here' the code for Adapter... public class SongsAdapter extends SimpleAdapter{ static List<HashMap<String,String>> songsList; Context context; LayoutInflater inflater; public SongsAdapter(Context context,List<HashMap<String,String>> imgListWeb,int layout,String[] from,int[] to,LayoutInflater inflater) { super(context,songsList,layout,from,to); this.songsList=songsList; this.context=context; this.inflater=inflater; // TODO Auto-generated constructor stub }@Override public View getView(int postition,View convertView,ViewGroup parent)throws java.lang.OutOfMemoryError{ try { View v = ((LayoutInflater) inflater).inflate(R.layout.row,null); ImageView images=(ImageView)v.findViewById(R.id.image); TextView tvTitle=(TextView)v.findViewById(R.id.text1); TextView tvAlbum=(TextView)v.findViewById(R.id.text2); TextView tvArtist=(TextView)v.findViewById(R.id.text3); HashMap<String,String> songsHash=songsList.get(postition); String path=songsHash.get("path"); String title=songsHash.get("title"); String album=songsHash.get("album"); String artist=songsHash.get("artist"); String imgPath=path; final ImageView imageView = (ImageView) v.findViewById(R.id.image); AsyncImageLoaderv asyncImageLoader=new AsyncImageLoaderv(); Bitmap cachedImage = asyncImageLoader.loadDrawable(imgPath, new AsyncImageLoaderv.ImageCallback() { public void imageLoaded(Bitmap imageDrawable, String imageUrl) { imageView.setImageBitmap(imageDrawable); } }); imageView.setImageBitmap(cachedImage); tvTitle.setText(title); tvAlbum.setText(album); tvArtist.setText(artist); return v; } catch(Exception e){ Log.e("error",e.toString()); } return null; } And also in my main program the focus is not entering the loop... The implementation in the loop isnt getting executed...Here's the code for it... public void list() { Log.d("#####","#####"); LayoutInflater inflater=getLayoutInflater(); String[] from={}; int[] n={}; adapter=new SongsAdapter(getApplicationContext(),songNodeDet,R.layout.row,from,n,inflater); lv.setAdapter(adapter);} private Handler handler = new Handler() { public void handleMessage(Message msg){ Log.d("*****","handler"); removeDialog(0); p.dismiss(); } }; public void webObjectList(Object[] imgListObj,String logInSess) throws XMLRPCException{ songNodeWeb = new HashMap<?,?>[imgListObj.length]; if(imgListObj!=null){ Log.e("completed","completed"); for(int i=0;i<imgListObj.length;i++){ //imgListObj.length songNodeWeb[i]=(HashMap<?,?>)imgListObj[i]; String nodeid=(String) songNodeWeb[i].get("nid"); Log.e("img",i+"completed"); HashMap<String,String> nData=new HashMap<String,String>(); nData.put("nid",nodeid); Object nodeget=client.call("node.get",logInSess,nodeid); HashMap<?,?> imgNode=(HashMap<?,?>)nodeget; String titleName=(String) imgNode.get("titles"); String movieName=(String) imgNode.get("album"); String singerName=(String) imgNode.get("artist"); nData.put("titles", titleName); nData.put("album", movieName); nData.put("artist", singerName); Object[] imgObject=(Object[])imgNode.get("title_format"); HashMap<?,?>[] imgDetails=new HashMap<?,?>[imgObject.length]; imgDetails[0]=(HashMap<?, ?>)imgObject[0]; String path=(String) imgDetails[0].get("filepath"); if(path.contains(" ")){ path=path.replace(" ", "%20"); } String imgPath="http://www.gorinka.com/"+path; paths.add(imgPath); nData.put("path", imgPath); Log.e("my path",path); String mime=(String)imgDetails[0].get("filemime"); nData.put("mime", mime); SongsList songs=new SongsList(titleName,movieName,singerName,imgPath,imgPath); SngList.add(i,songs); songNodeDet.add(i,nData); } Log.e("paths values",paths.toString()); // return imgNodeDet; handler.sendEmptyMessage(0); } } public void getSongs() throws MalformedURLException, XMLRPCException { String ur="http://www.gorinka.com/?q=services/xmlrpc"; URL u=new URL(ur); client = new XMLRPCClient(u); //Connecting to the website HashMap<?, ?> siteConn =(HashMap<?, ?>) client.call("system.connect"); // Getting initial sessio id String initSess=(String)siteConn.get("sessid"); //Login to the site using session id HashMap<?, ?> logInConn =(HashMap<?, ?>) client.call("user.login",initSess,"prakash","stellentsoft2009"); //Getting Login sessid logInSess=(String)logInConn.get("sessid"); websongListObject =(Object[]) client.call("nodetype.get",logInSess,""); webObjectList(websongListObject,logInSess); Log.d("webObjectList","webObjectList"); runOnUiThread(returnRes); } }

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  • Simple Grouping With TableSorter Plugin

    - by HurnsMobile
    Im playing around with the Tablesorter plug-in for jQuery and was trying to get a very simple grouping functionality added into it. Using the follow html/js works great until you click sort again and reverse the order. The headers get moved to the bottom of the group when this happens. The following is my (admitedly hacky) attempt at it. Does anyone have any ideas? <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Table Manipulation Test</title> <link type="text/css" href="css/ui-lightness/jquery-ui-1.8.1.custom.css" rel="stylesheet" /> <link rel="stylesheet" href="tablesorter/themes/green/style.css" type="text/css"/> <script type="text/javascript" src="js/jquery-1.4.2.min.js"></script> <script type="text/javascript" src="js/jquery-ui-1.8.1.custom.min.js"></script> <script type="text/javascript" src="tablesorter/jquery.tablesorter.min.js"></script> <script type="text/javascript"> $(document).ready(function() { $("#test_table").tablesorter({ sortForce: [[3,0]] }); $(".group_details").hide(); $(".group_header").click(function(){ var group = $(this).attr("group"); var $expander = $(this).children("td.expanderguy") if ($("." + group + ":visible").length){ $("." + group + "").fadeOut('fast'); $expander.html("<img src='icons/plus.gif'>"); } else{ $("." + group + "").fadeIn('fast'); $expander.html("<img src='icons/minus.gif'>"); } }); } ); </script> <style type="text/css"> .group_header td{ background-color: #888888; !important } </style> </head> <body> <table id="test_table" class="tablesorter"> <thead> <tr><th>First Name</th><th>Last Name</th><th>Email</th><th>Due Date</th><th>Amount Due</th></tr> </thead> <tbody> <tr class="group_header" group="group1"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Monday, June 7</td><td></td></tr> <tr class="group_details group1"><td>Flavian</td><td>Wenceslas</td><td>[email protected]</td><td>Monday, June 7</td><td>$100</td></tr> <tr class="group_details group1"><td>Gordian</td><td>Ives</td><td>[email protected]</td><td>Monday, June 7</td><td>$1700</td></tr> <tr class="group_details group1"><td>Saladin</td><td>Tarquin</td><td>[email protected]</td><td>Monday, June 7</td><td>$1700</td></tr> <tr class="group_details group1"><td>Urban</td><td>Cyprian</td><td>[email protected]</td><td>Monday, June 7</td><td>$1500</td></tr> <tr class="group_details group1"><td>Sargon</td><td>Swithun</td><td>[email protected]</td><td>Monday, June 7</td><td>$1100</td></tr> <tr class="group_details group1"><td>Pompey</td><td>Ladislas</td><td>[email protected]</td><td>Monday, June 7</td><td>$300</td></tr> <tr class="group_details group1"><td>Attila</td><td>Hiawatha</td><td>[email protected]</td><td>Monday, June 7</td><td>$200</td></tr> <tr class="group_header" group="group2"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Tuesday, June 8</td><td></td></tr> <tr class="group_details group2"><td>Bruce</td><td>Fenton</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1700</td></tr> <tr class="group_details group2"><td>Wade</td><td>Sequoia</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1400</td></tr> <tr class="group_details group2"><td>Eddie</td><td>Jerold</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1100</td></tr> <tr class="group_details group2"><td>Lynn</td><td>Lucan</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1200</td></tr> <tr class="group_details group2"><td>Taegan</td><td>Tadg</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$100</td></tr> <tr class="group_details group2"><td>Clyde</td><td>Reed</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$6100</td></tr> <tr class="group_details group2"><td>Alaois</td><td>Art</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$2100</td></tr> <tr class="group_details group2"><td>Gilbert</td><td>Patsy</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1500</td></tr> <tr class="group_header" group="group3"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Wednesday, June 9</td><td></td></tr> <tr class="group_details group3" ><td>Clem</td><td>Eben</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$2100</td></tr> <tr class="group_details group3" ><td>Elijah</td><td>Julyan</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$2100</td></tr> <tr class="group_details group3" ><td>Marvyn</td><td>Damian</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$1100</td></tr> <tr class="group_details group3" ><td>Sawyer</td><td>Ryker</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$500</td></tr> </tbody> </table> </body>

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  • Query on simple C++ threadpool implementation

    - by ticketman
    Stackoverflow has been a tremendous help to me and I'd to give something back to the community. I have been implementing a simple threadpool using the tinythread C++ portable thread library, using what I have learnt from Stackoverflow. I am new to thread programming, so not that comfortable with mutexes, etc. I have a question best asked after presenting the code (which runs quite well under Linux): // ThreadPool.h class ThreadPool { public: ThreadPool(); ~ThreadPool(); // Creates a pool of threads and gets them ready to be used void CreateThreads(int numOfThreads); // Assigns a job to a thread in the pool, but doesn't start the job // Each SubmitJob call will use up one thread of the pool. // This operation can only be undone by calling StartJobs and // then waiting for the jobs to complete. On completion, // new jobs may be submitted. void SubmitJob( void (*workFunc)(void *), void *workData ); // Begins execution of all the jobs in the pool. void StartJobs(); // Waits until all jobs have completed. // The wait will block the caller. // On completion, new jobs may be submitted. void WaitForJobsToComplete(); private: enum typeOfWorkEnum { e_work, e_quit }; class ThreadData { public: bool ready; // thread has been created and is ready for work bool haveWorkToDo; typeOfWorkEnum typeOfWork; // Pointer to the work function each thread has to call. void (*workFunc)(void *); // Pointer to work data void *workData; ThreadData() : ready(false), haveWorkToDo(false) { }; }; struct ThreadArgStruct { ThreadPool *threadPoolInstance; int threadId; }; // Data for each thread ThreadData *m_ThreadData; ThreadPool(ThreadPool const&); // copy ctor hidden ThreadPool& operator=(ThreadPool const&); // assign op. hidden // Static function that provides the function pointer that a thread can call // By including the ThreadPool instance in the void * parameter, // we can use it to access other data and methods in the ThreadPool instance. static void ThreadFuncWrapper(void *arg) { ThreadArgStruct *threadArg = static_cast<ThreadArgStruct *>(arg); threadArg->threadPoolInstance->ThreadFunc(threadArg->threadId); } // The function each thread calls void ThreadFunc( int threadId ); // Called by the thread pool destructor void DestroyThreadPool(); // Total number of threads available // (fixed on creation of thread pool) int m_numOfThreads; int m_NumOfThreadsDoingWork; int m_NumOfThreadsGivenJobs; // List of threads std::vector<tthread::thread *> m_ThreadList; // Condition variable to signal each thread has been created and executing tthread::mutex m_ThreadReady_mutex; tthread::condition_variable m_ThreadReady_condvar; // Condition variable to signal each thread to start work tthread::mutex m_WorkToDo_mutex; tthread::condition_variable m_WorkToDo_condvar; // Condition variable to signal the main thread that // all threads in the pool have completed their work tthread::mutex m_WorkCompleted_mutex; tthread::condition_variable m_WorkCompleted_condvar; }; cpp file: // // ThreadPool.cpp // #include "ThreadPool.h" // This is the thread function for each thread. // All threads remain in this function until // they are asked to quit, which only happens // when terminating the thread pool. void ThreadPool::ThreadFunc( int threadId ) { ThreadData *myThreadData = &m_ThreadData[threadId]; std::cout << "Hello world: Thread " << threadId << std::endl; // Signal that this thread is ready m_ThreadReady_mutex.lock(); myThreadData->ready = true; m_ThreadReady_condvar.notify_one(); // notify the main thread m_ThreadReady_mutex.unlock(); while(true) { //tthread::lock_guard<tthread::mutex> guard(m); m_WorkToDo_mutex.lock(); while(!myThreadData->haveWorkToDo) // check for work to do m_WorkToDo_condvar.wait(m_WorkToDo_mutex); // if no work, wait here myThreadData->haveWorkToDo = false; // need to do this before unlocking the mutex m_WorkToDo_mutex.unlock(); // Do the work switch(myThreadData->typeOfWork) { case e_work: std::cout << "Thread " << threadId << ": Woken with work to do\n"; // Do work myThreadData->workFunc(myThreadData->workData); std::cout << "#Thread " << threadId << ": Work is completed\n"; break; case e_quit: std::cout << "Thread " << threadId << ": Asked to quit\n"; return; // ends the thread } // Now to signal the main thread that my work is completed m_WorkCompleted_mutex.lock(); m_NumOfThreadsDoingWork--; // Unsure if this 'if' would make the program more efficient // if(NumOfThreadsDoingWork == 0) m_WorkCompleted_condvar.notify_one(); // notify the main thread m_WorkCompleted_mutex.unlock(); } } ThreadPool::ThreadPool() { m_numOfThreads = 0; m_NumOfThreadsDoingWork = 0; m_NumOfThreadsGivenJobs = 0; } ThreadPool::~ThreadPool() { if(m_numOfThreads) { DestroyThreadPool(); delete [] m_ThreadData; } } void ThreadPool::CreateThreads(int numOfThreads) { // Check a thread pool has already been created if(m_numOfThreads > 0) return; m_NumOfThreadsGivenJobs = 0; m_NumOfThreadsDoingWork = 0; m_numOfThreads = numOfThreads; m_ThreadData = new ThreadData[m_numOfThreads]; ThreadArgStruct threadArg; for(int i=0; i<m_numOfThreads; ++i) { threadArg.threadId = i; threadArg.threadPoolInstance = this; // Creates the thread and save in a list so we can destroy it later m_ThreadList.push_back( new tthread::thread( ThreadFuncWrapper, (void *)&threadArg ) ); // It takes a little time for a thread to get established. // Best wait until it gets established before creating the next thread. m_ThreadReady_mutex.lock(); while(!m_ThreadData[i].ready) // Check if thread is ready m_ThreadReady_condvar.wait(m_ThreadReady_mutex); // If not, wait here m_ThreadReady_mutex.unlock(); } } // Adds a job to the batch, but doesn't start the job void ThreadPool::SubmitJob(void (*workFunc)(void *), void *workData) { // Check that the thread pool has been created if(!m_numOfThreads) return; if(m_NumOfThreadsGivenJobs >= m_numOfThreads) return; m_ThreadData[m_NumOfThreadsGivenJobs].workFunc = workFunc; m_ThreadData[m_NumOfThreadsGivenJobs].workData = workData; std::cout << "Submitted job " << m_NumOfThreadsGivenJobs << std::endl; m_NumOfThreadsGivenJobs++; } void ThreadPool::StartJobs() { // Check that the thread pool has been created // and some jobs have been assigned if(!m_numOfThreads || !m_NumOfThreadsGivenJobs) return; // Set 'haveworkToDo' flag for all threads m_WorkToDo_mutex.lock(); for(int i=0; i<m_NumOfThreadsGivenJobs; ++i) m_ThreadData[i].haveWorkToDo = true; m_NumOfThreadsDoingWork = m_NumOfThreadsGivenJobs; // Reset this counter so we can resubmit jobs later m_NumOfThreadsGivenJobs = 0; // Notify all threads they have work to do m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); } void ThreadPool::WaitForJobsToComplete() { // Check that a thread pool has been created if(!m_numOfThreads) return; m_WorkCompleted_mutex.lock(); while(m_NumOfThreadsDoingWork > 0) // Check if all threads have completed their work m_WorkCompleted_condvar.wait(m_WorkCompleted_mutex); // If not, wait here m_WorkCompleted_mutex.unlock(); } void ThreadPool::DestroyThreadPool() { std::cout << "Ask threads to quit\n"; m_WorkToDo_mutex.lock(); for(int i=0; i<m_numOfThreads; ++i) { m_ThreadData[i].haveWorkToDo = true; m_ThreadData[i].typeOfWork = e_quit; } m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); // As each thread terminates, catch them here for(int i=0; i<m_numOfThreads; ++i) { tthread::thread *t = m_ThreadList[i]; // Wait for thread to complete t->join(); } m_numOfThreads = 0; } Example of usage: (this calculates pi-squared/6) struct CalculationDataStruct { int inputVal; double outputVal; }; void LongCalculation( void *theSums ) { CalculationDataStruct *sums = (CalculationDataStruct *)theSums; int terms = sums->inputVal; double sum; for(int i=1; i<terms; i++) sum += 1.0/( double(i)*double(i) ); sums->outputVal = sum; } int main(int argc, char** argv) { int numThreads = 10; // Create pool ThreadPool threadPool; threadPool.CreateThreads(numThreads); // Create thread workspace CalculationDataStruct sums[numThreads]; // Set up jobs for(int i=0; i<numThreads; i++) { sums[i].inputVal = 3000*(i+1); threadPool.SubmitJob(LongCalculation, &sums[i]); } // Run the jobs threadPool.StartJobs(); threadPool.WaitForJobsToComplete(); // Print results for(int i=0; i<numThreads; i++) std::cout << "Sum of " << sums[i].inputVal << " terms is " << sums[i].outputVal << std::endl; return 0; } Question: In the ThreadPool::ThreadFunc method, would better performance be obtained if the following if statement if(NumOfThreadsDoingWork == 0) was included? Also, I'd be grateful of criticisms and ways to improve the code. At the same time, I hope the code is of use to others.

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