Search Results

Search found 23473 results on 939 pages for 'game programming'.

Page 246/939 | < Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >

  • Are there any downsides in using C++ for network daemons?

    - by badcat
    Hey guys! I've been writing a number of network daemons in different languages over the past years, and now I'm about to start a new project which requires a new custom implementation of a properitary network protocol. The said protocol is pretty simple - some basic JSON formatted messages which are transmitted in some basic frame wrapping to have clients know that a message arrived completely and is ready to be parsed. The daemon will need to handle a number of connections (about 200 at the same time) and do some management of them and pass messages along, like in a chat room. In the past I've been using mostly C++ to write my daemons. Often with the Qt4 framework (the network parts, not the GUI parts!), because that's what I also used for the rest of the projects and it was simple to do and very portable. This usually worked just fine, and I didn't have much trouble. Being a Linux administrator for a good while now, I noticed that most of the network daemons in the wild are written in plain C (of course some are written in other languages, too, but I get the feeling that 80% of the daemons are written in plain C). Now I wonder why that is. Is this due to a pure historic UNIX background (like KISS) or for plain portability or reduction of bloat? What are the reasons to not use C++ or any "higher level" languages for things like daemons? Thanks in advance! Update 1: For me using C++ usually is more convenient because of the fact that I have objects which have getter and setter methods and such. Plain C's "context" objects can be a real pain at some point - especially when you are used to object oriented programming. Yes, I'm aware that C++ is a superset of C, and that C code is basically C++. But that's not the point. ;)

    Read the article

  • How do you use stl's functions like for_each?

    - by thomas-gies
    I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

    Read the article

  • Ruby: counters, counting and incrementing

    - by Shyam
    Hi, If you have seen my previous questions, you'd already know I am a big nuby when it comes to Ruby. So, I discovered this website which is intended for C programming, but I thought whatever one can do in C, must be possible in Ruby (and more readable too). The challenge is to print out a bunch of numbers. I discovered this nifty method .upto() and I used a block (and actually understanding its purpose). However, in IRb, I got some unexpected behavior. class MyCounter def run 1.upto(10) { |x| print x.to_s + " " } end end irb(main):033:0> q = MyCounter.new => #<MyCounter:0x5dca0> irb(main):034:0> q.run 1 2 3 4 5 6 7 8 9 10 => 1 I have no idea where the = 1 comes from :S Should I do this otherwise? I am expecting to have this result: 1 2 3 4 5 6 7 8 9 10 Thank you for your answers, comments and feedback!

    Read the article

  • Freelance web hosting - what are good LAMP choices?

    - by tkotitan
    I think it's best if I ask this question with an example scenario. Let's say your mom-and-pop local hardware store has never had a website, and they want you, the freelance developer to build them a website. You have all the skills to run a LAMP setup and admin a system, so the difficult question you ask yourself is - where will I host it? As you aren't going to host it out of the machine in your apartment. Let's say you want to be able to customize your own system, install the version of PHP you want, and manage your own database. Perhaps the best kind of hosting is to get a virtual machine so you can customize the system as you see fit. But this essentially a "set it and forget it" site you make, bill by the hour for, and then are done. In other words, the hosting should not be an issue. Given the requirements of hosting a website: Unlimited growth potential needing good amounts of bandwidth to handle visitors Wide range of system and programming options allowing it to be portable Relatively cheap (not necessarily the cheapest) or reasonable scaling cost Reliable hosting with good support Hosted entirely on the host company's hardware Who would you pick to host this website? Yes I am asking for a business/company recommendation. Is there a clear answer for this scenario, or a good source that can reliably give the current answer? I know there are all kinds of schemes out there. I'm just wondering if any one company fills the bill for freelancers and stands out in such a crowded market.

    Read the article

  • Is it OK to write code after [super dealloc]? (Objective-C)

    - by Richard J. Ross III
    I have a situation in my code, where I cannot clean up my classes objects without first calling [super dealloc]. It is something like this: // Baseclass.m @implmentation Baseclass ... -(void) dealloc { [self _removeAllData]; [aVariableThatBelongsToMe release]; [anotherVariableThatBelongsToMe release]; [super dealloc]; } ... @end This works great. My problem is, when I went to subclass this huge and nasty class (over 2000 lines of gross code), I ran into a problem: when I released my objects before calling [super dealloc] I had zombies running through the code that were activated when I called the [self _removeAllData] method. // Subclass.m @implementation Subclass ... -(void) deallloc { [super dealloc]; [someObjectUsedInTheRemoveAllDataMethod release]; } ... @end This works great, and It didn't require me to refactor any code. My question Is this: Is it safe for me to do this, or should I refactor my code? Or maybe autorelease the objects? I am programming for iPhone if that matters any.

    Read the article

  • Alter a function as a parameter before evaluating it in R?

    - by Shane
    Is there any way, given a function passed as a parameter, to alter its input parameter string before evaluating it? Here's pseudo-code for what I'm hoping to achieve: test.func <- function(a, b) { # here I want to alter the b expression before evaluating it: b(..., val1=a) } Given the function call passed to b, I want to add in a as another parameter without needing to always specify ... in the b call. So the output from this test.func call should be: test.func(a="a", b=paste(1, 2)) "1" "2" "a" Edit: Another way I could see doing something like this would be if I could assign the additional parameter within the scope of the parent function (again, as pseudo-code); in this case a would be within the scope of t1 and hence t2, but not globally assigned: t2 <- function(...) { paste(a=a, ...) } t1 <- function(a, b) { local( { a <<- a; b } ) } t1(a="a", b=t2(1, 2)) This is somewhat akin to currying in that I'm nesting the parameter within the function itself. Edit 2: Just to add one more comment to this: I realize that one related approach could be to use "prototype-based programming" such that things would be inherited (which could be achieved with the proto package). But I was hoping for a easier way to simply alter the input parameters before evaluating in R.

    Read the article

  • Help! I'm a Haskell Newbie

    - by Darknight
    I've only just dipped my toe in the world of Haskell as part of my journey of programming enlightenment (moving on from, procedural to OOP to concurrent to now functional). I've been trying an online Haskell Evaluator. However I'm now stuck on a problem: Create a simple function that gives the total sum of an array of numbers. In a procedural language this for me is easy enough (using recursion) (c#) : private int sum(ArrayList x, int i) { if (!(x.Count < i + 1)) { int t = 0; t = x.Item(i); t = sum(x, i + 1) + t; return t; } } All very fine however my failed attempt at Haskell was thus: let sum x = x+sum in map sum [1..10] this resulted in the following error (from that above mentioned website): Occurs check: cannot construct the infinite type: a = a -> t Please bear in mind I've only used Haskell for the last 30 minutes! I'm not looking simply for an answer but a more explanation of it. Thanks in advanced.

    Read the article

  • Which way to store this data is effective?

    - by Tattat
    I am writing a game, which need a map, and I want to store the map. The first thing I can think of, is using a 2D-array. But the problem is what data should I store in the 2D-array. The player can tap different place to have different reaction. So, I am thinking store a 2D-array with objects, when player click some position, and I find it in the array, and use the object in that array to execute a cmd. But I have a concern that storing lots of object may use lots of memory. So, I am think storing char/int only. But it seems that not enough for me. I want to store the data like that: { Type:1 Color:Green } No matter what color is, if they are all type 1, the have same reactions in logic, but the visual effect is based on the color. So, it is not easy to store using a prue char/int data, unless I make something like this: 1-5 --> all type 1. 1=color green , 2=color red, 3 = color yellow.... ... 6-10 --> all type 2. 2 = color green, 2 = color red ... ... So, do you have any ideas on how to minimize the ram use, but also easy for me to read... ...thx

    Read the article

  • Parallelize or vectorize all-against-all operation on a large number of matrices?

    - by reve_etrange
    I have approximately 5,000 matrices with the same number of rows and varying numbers of columns (20 x ~200). Each of these matrices must be compared against every other in a dynamic programming algorithm. In this question, I asked how to perform the comparison quickly and was given an excellent answer involving a 2D convolution. Serially, iteratively applying that method, like so list = who('data_matrix_prefix*') H = cell(numel(list),numel(list)); for i=1:numel(list) for j=1:numel(list) if i ~= j eval([ 'H{i,j} = compare(' char(list(i)) ',' char(list(j)) ');']); end end end is fast for small subsets of the data (e.g. for 9 matrices, 9*9 - 9 = 72 calls are made in ~1 s). However, operating on all the data requires almost 25 million calls. I have also tried using deal() to make a cell array composed entirely of the next element in data, so I could use cellfun() in a single loop: # who(), load() and struct2cell() calls place k data matrices in a 1D cell array called data. nextData = cell(k,1); for i=1:k [nextData{:}] = deal(data{i}); H{:,i} = cellfun(@compare,data,nextData,'UniformOutput',false); end Unfortunately, this is not really any faster, because all the time is in compare(). Both of these code examples seem ill-suited for parallelization. I'm having trouble figuring out how to make my variables sliced. compare() is totally vectorized; it uses matrix multiplication and conv2() exclusively (I am under the impression that all of these operations, including the cellfun(), should be multithreaded in MATLAB?). Does anyone see a (explicitly) parallelized solution or better vectorization of the problem?

    Read the article

  • SYN receives RST,ACK very frequently

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

    Read the article

  • Heap Algorithmic Issue

    - by OberynMarDELL
    I am having this algorithmic problem that I want to discuss about. Its not about find a solution but about optimization in terms of runtime. So here it is: Suppose we have a race court of Length L and a total of N cars that participate on the race. The race rules are simple. Once a car overtakes an other car the second car is eliminated from the race. The race ends when no more overtakes are possible to happen. The tricky part is that the k'th car has a starting point x[k] and a velocity v[k]. The points are given in an ascending order, but the velocities may differ. What I've done so far: Given that a car can get overtaken only by its previous, I calculated the time that it takes for each car to reach its next one t = (x[i] - x[i+1])/(v[i] - v[i+1]) and I insert these times onto a min heap in O(n log n). So in theory I have to pop the first element in O(logn), find its previous, pop it as well , update its time and insert it in the heap once more, much like a priority queue. My main problem is how I can access specific points of a heap in O(log n) or faster in order to keep the complexity in O(n log n) levels. This program should be written on Haskell so I would like to keep things simple as far as possible EDIT: I Forgot to write the actual point of the race. The goal is to find the order in which cars exit the game

    Read the article

  • Finding k elements of length-n list that sum to less than t in O(nlogk) time

    - by tresbot
    This is from Programming Pearls ed. 2, Column 2, Problem 8: Given a set of n real numbers, a real number t, and an integer k, how quickly can you determine whether there exists a k-element subset of the set that sums to at most t? One easy solution is to sort and sum the first k elements, which is our best hope to find such a sum. However, in the solutions section Bentley alludes to a solution that takes nlog(k) time, though he gives no hints for how to find it. I've been struggling with this; one thought I had was to go through the list and add all the elements less than t/k (in O(n) time); say there are m1 < k such elements, and they sum to s1 < t. Then we are left needing k - m1 elements, so we can scan through the list again in O(n) time looking for all elements less than (t - s1)/(k - m1). Add in again, to get s2 and m2, then again if m2 < k, look for all elements less than (t - s2)/(k - m2). So: def kSubsetSumUnderT(inList, k, t): outList = [] s = 0 m = 0 while len(outList) < k: toJoin = [i for i in inList where i < (t - s)/(k - m)] if len(toJoin): if len(toJoin) >= k - m: toJoin.sort() if(s0 + sum(toJoin[0:(k - m - 1)]) < t: return True return False outList = outList + toJoin s += sum(toJoin) m += len(toJoin) else: return False My intuition is that this might be the O(nlog(k)) algorithm, but I am having a hard time proving it to myself. Thoughts?

    Read the article

  • Friday Fun: The Search For Wondla

    - by Asian Angel
    The best day of the week is finally here again, so it is time to have some fun while waiting to go home for the weekend. The game we have for you today takes you far into humanity’s future where you journey with Eva Nine in her quest to find other humans. Note: Today’s game comes with a double bonus! First, there is a sequel game that you can move on to once you have completed the first one. Second, there are three wallpapers available in multiple sizes for those who enjoy the characters and artwork presented in the game (see below). The Search For Wondla The object of the game is to find the differences between two similar looking images based on artwork from The Search For Wondla by Tony DiTerlizzi. Are you ready to join Eva Nine in her quest to find other humans in the future? Note: There is a version available for those who would like to play The Search For Wondla on their iPads! The first game has 28 levels of difference finding goodness for you to work through. Each level will list the minimum number of differences that you need to find to progress to the next level. If you need a hint along the way just click on the Shake or Reveal options at the bottom of the game play window. Get a level completed quickly enough and you get bonus points! There will also be differences in the images for individual levels each time you play the game, so have fun! Note: The second game has 12 levels to complete. To give you a good feel for the game we have covered the first six levels here and provided seven clues for each level (you are only required to find a minimum of five). Eva Nine viewing the holographic outdoor projections in the main hub of her living quarters… Eva Nine is in a grumpy mood as Muthr visits her at bedtime… Eva Nine in her secret hideaway visiting old “childhood friends” as she contemplates her recent survival test failure. Eva Nine viewing the entire set of floor plans for the underground sanctuary where she was born and has been growing up. Eva Nine’s escape to the surface as the underground sanctuary is attacked by the bounty hunter creature Besteel. Eva Nine on the surface for the first time in her young life. Will she be successful in her quest? There is only one way to find out! Play The Search For Wondla Part 1 Play The Search For Wondla Part 2 Bonus Content If you have enjoyed this game you can learn more about the book and download the three wallpapers shown here by visiting the link below! Note: The wallpapers come in the following sizes: 1024*768, 1280*800, 1280*1024, 1440*900, iPhone, iPhone4, and iPad (click on the Extras link at the bottom of the page). Visit the Search For Wondla Homepage Do you enjoy playing difference finding games? Then you will definitely want to have a look at another wonderful game that we have covered here: Friday Fun: Isis Latest Features How-To Geek ETC The How-To Geek Guide to Learning Photoshop, Part 8: Filters Get the Complete Android Guide eBook for Only 99 Cents [Update: Expired] Improve Digital Photography by Calibrating Your Monitor The How-To Geek Guide to Learning Photoshop, Part 7: Design and Typography How to Choose What to Back Up on Your Linux Home Server How To Harmonize Your Dual-Boot Setup for Windows and Ubuntu Hang in There Scrat! – Ice Age Wallpaper How Do You Know When You’ve Passed Geek and Headed to Nerd? On The Tip – A Lamborghini Theme for Chrome and Iron What if Wile E. Coyote and the Road Runner were Human? [Video] Peaceful Winter Cabin Wallpaper Store Tabs for Later Viewing in Opera with Tab Vault

    Read the article

  • How do I do JavaScript Array Animation

    - by Henry
    I'm making a game but don't know how to do Array Animation with the png Array and game Surface that I made below. I'm trying to make it so that when the Right arrow key is pressed, the character animates as if it is walking to the right and when the Left arrow key is pressed it animates as if it is walking to the left (kind of like Mario). I put everything on a surface instead of the canvas. Everything is explained in the code below. I couldn't find help on this anywhere. I hope what I got below makes sense. I'm basically a beginner with JavaScript. I'll be back if more is needed: <!doctype html5> <html> <head></head> <script src="graphics.js"></script> <script src="object.js"></script> <body onkeydown ="keyDown(event)" onkeyup ="keyUp(event)" ></body> <script> //"Surface" is where I want to display my animation. It's like the HTML // canvas but it's not that. It's just the surface to where everything in the //game and the game itself will be displayed. var Surface = new Graphics(600, 400, "skyblue"); //here's the array that I want to use for animation var player = new Array("StandsRight.png", "WalksRight.png", "StandsLeft.png","WalksLeft.png" ); //Here is the X coordinate, Y coordinate, the beginning png for the animation, //and the object's name "player." I also turned the array into an object (but //I don't know if I was supposed to do that or not). var player = new Object(50, 100, 40, 115, "StandsRight.png","player"); //When doing animation I know that it requires a "loop", but I don't // know how to connect it so that it works with the arrays so that //it could animate. var loop = 0; //this actually puts "player" on screen. It makes player visible and //it is where I would like the animation to occur. Surface.drawObject(player); //this would be the key that makes "player" animation in the righward direction function keyDown(e) { if (e.keyCode == 39); } //this would be the key that makes "player" animation in the leftward direction function keyUp(e){ if (e.keyCode == 39); } //this is the Mainloop where the game will function MainLoop(); //the mainloop functionized function MainLoop(){ //this is how fast or slow I could want the entire game to go setTimeout(MainLoop, 10); } </script> </html> From here, are the "graphic.js" and the "object.js" files below. In this section is the graphics.js file. This graphics.js part below is linked to the: script src="graphics.js" html script section that I wrote above. Basically, below is a seperate file that I used for Graphics, and to run the code above, make this graphics.js code that I post below here, a separate filed called: graphics.js function Graphics(w,h,c) { document.body.innerHTML += "<table style='position:absolute;font- size:0;top:0;left:0;border-spacing:0;border- width:0;width:"+w+";height:"+h+";background-color:"+c+";' border=1><tr><td> </table>\n"; this.drawRectangle = function(x,y,w,h,c,n) { document.body.innerHTML += "<div style='position:absolute;font-size:0;left:" + x + ";top:" + y + ";width:" + w + ";height:" + h + ";background-color:" + c + ";' id='" + n + "'></div>\n"; } this.drawTexture = function(x,y,w,h,t,n) { document.body.innerHTML += "<img style='position:absolute;font-size:0;left:" + x + ";top:" + y + ";width:" + w + ";height:" + h + ";' id='" + n + "' src='" + t + "'> </img>\n"; } this.drawObject = function(o) { document.body.innerHTML += "<img style='position:absolute;font-size:0;left:" + o.X + ";top:" + o.Y + ";width:" + o.Width + ";height:" + o.Height + ";' id='" + o.Name + "' src='" + o.Sprite + "'></img>\n"; } this.moveGraphic = function(x,y,n) { document.getElementById(n).style.left = x; document.getElementById(n).style.top = y; } this.removeGraphic = function(n){ document.getElementById(n).parentNode.removeChild(document.getElementById(n)); } } Finally, is the object.js file linked to the script src="object.js"" in the html game file above the graphics.js part I just wrote. Basically, this is a separate file too, so thus, in order to run or test the html game code in the very first section I wrote, a person has to also make this code below a separate file called: object.js I hope this helps: function Object(x,y,w,h,t,n) { this.X = x; this.Y = y; this.Velocity_X = 0; this.Velocity_Y = 0; this.Previous_X = 0; this.Previous_Y = 0; this.Width = w; this.Height = h; this.Sprite = t; this.Name = n; this.Exists = true; } In all, this game is made based on a tutorial on youtube at: http://www.youtube.com/watch?v=t2kUzgFM4lY&feature=relmfu I'm just trying to learn how to add animations with it now. I hope the above helps. If not, let me know. Thanks

    Read the article

  • Wireless connection drops when wired computer starts a game.

    - by Skadlig
    Starting this week I have had a strange problem on my network. Some background of my setup: Internet is provided by a adsl-modem. A D-link Dir-600 router is hooked up to to adsl-modem. My computer is hooked up to the router using a cat-5 cable. My wife's computer is hooked up using a wireless usb dongle, TP-Link TL-WN821N. Both computers use windows 7 64-bit home premium. Up until this week everything was normal, we could for instance play Dungeons & Dragons Online together without any network issues. Now every time I start DDO or any other network game, for instance L4D, the whole wireless network drops. I have confirmed that it's not just her computer using an Samsung Galaxy Spica android phone. Shutting down the game on my end restores the wireless connection automagicly. My wife can start DDO without the net dropping but if I plug in a wireless network card in my computer and start up the game the connection drops. So it seems like something my computer, and my computer only, does when starting a game makes the wireless connection write a sad note and kill it self but for the life of me I can't figure out what that might be. I could hook her computer up using cat-5 but I would prefer not to do that. Does anyone have any suggestions as to what the problem might be, what I can do to fix it or what I should do to get more data regarding what is happening?

    Read the article

  • SQL queries break our game! (Back-end server is at capacity)

    - by TimH
    We have a Facebook game that stores all persistent data in a MySQL database that is running on a large Amazon RDS instance. One of our tables is 2GB in size. If I run any queries on that table that take more than a couple of seconds, any SQL actions performed by our game will fail with the error: HTTP/1.1 503 Service Unavailable: Back-end server is at capacity This obviously brings down our game! I've monitored CPU usage on the RDS instance during these periods, and though it does spike, it doesn't go much over 50%. Previously we were on a smaller instance size and it did hit 100%, so I'd hoped just throwing more CPU capacity at the problem would solve it. I now think it's an issue with the number of open connections. However, I've only been working with SQL for 8 months or so, so I'm no expert on MySQL configuration. Is there perhaps some configuration setting I can change to prevent these queries from overloading the server, or should I just not be running them whilst our game is up? I'm using MySQL Workbench to run the queries. Here's an example.... SELECT * FROM BlueBoxEngineDB.Transfer WHERE Amount = 1000 AND FromUserId = 4 AND Status='Complete'; As you can see, it's not overly complex. There are only 5 columns in the table. Any help would be very much appreciated - Thanks!

    Read the article

  • Autoloading Development or Production configs (best practices)

    - by Xeoncross
    When programming sites you usually have one set of config files for the development environment and another set for the production server (or one file with both settings). I am assuming all projects should be handled by version control like git or svn. Manual file transfers (like FTP) is wrong on so many levels. How you enable/disable the correct settings (so that your system knows which ones to use) is a problem for me. Each system I work on just kind of jimmy-rigs a solution. Below are the 3 methods I know of and I am hoping that someone can submit a more elegant solutions. 1) File Based The system loads a folder structure based on the URL requested. /site.com /site.fakeTLD /lib index.php For example, if the url is http://site.com then the system loads the production config files located in the site.com folder. However, if I'm working on the site locally I visit http://site.fakeTLD to work on the local copy of the site. To setup this I edit my hosts file and add site.fakeTLD to point to my own computer (127.0.0.1/localhost) and then create a vhost in apache. So now I can work on the codebase locally and then push to the server without any trouble. The problem is that this is susceptible to a "host" injection attack. So someone loading site.com could set the host to site.fakeTLD and then the system would load my development config files instead of production. 2) Config Based The config files contain on section for development - and one for production. The problem is that each time you go to push your changes to the repo you have to edit the file to specify which set of config options should be used. $use = 'production'; //'development'; This leaves the repo open to human error should one of the developers forget to enable the right setting. 3) File System Check Based All the development machines have an extra empty file called "development.txt" or something. Each time the system loads it checks for this file - if found then it knows it is in development mode - if missing then it knows it is in production mode. Since the file is NEVER ADDED to the repo then it will never be pushed (and checked out) on the production machine. However, this just doesn't feel right and causes a slight slow down since all filesystem checks are slow. Is there anyway that the server can auto-detect wither to use the development or production configs?

    Read the article

  • What are five things you hate about your favorite language?

    - by brian d foy
    There's been a cluster of Perl-hate on Stackoverflow lately, so I thought I'd bring my "Five things you hate about your favorite language" question to StackOverflow. Take your favorite language and tell me five things you hate about it. Those might be things that just annoy you, admitted design flaws, recognized performance problems, or any other category. You just have to hate it, and it has to be your favorite language. Don't compare it to another language, and don't talk about languages that you already hate. Don't talk about the things you like in your favorite language. I just want to hear the things that you hate but tolerate so you can use all of the other stuff, and I want to hear it about the language you wished other people would use. I ask this whenever someone tries to push their favorite language on me, and sometimes as an interview question. If someone can't find five things to hate about his favorite tool, he don't know it well enough to either advocate it or pull in the big dollars using it. He hasn't used it in enough different situations to fully explore it. He's advocating it as a culture or religion, which means that if I don't choose his favorite technology, I'm wrong. I don't care that much which language you use. Don't want to use a particular language? Then don't. You go through due diligence to make an informed choice and still don't use it? Fine. Sometimes the right answer is "You have a strong programming team with good practices and a lot of experience in Bar. Changing to Foo would be stupid." This is a good question for code reviews too. People who really know a codebase will have all sorts of suggestions for it, and those who don't know it so well have non-specific complaints. I ask things like "If you could start over on this project, what would you do differently?" In this fantasy land, users and programmers get to complain about anything and everything they don't like. "I want a better interface", "I want to separate the model from the view", "I'd use this module instead of this other one", "I'd rename this set of methods", or whatever they really don't like about the current situation. That's how I get a handle on how much a particular developer knows about the codebase. It's also a clue about how much of the programmer's ego is tied up in what he's telling me. Hate isn't the only dimension of figuring out how much people know, but I've found it to be a pretty good one. The things that they hate also give me a clue how well they are thinking about the subject.

    Read the article

  • Variable sized packet structs with vectors

    - by Rev316
    Lately I've been diving into network programming, and I'm having some difficulty constructing a packet with a variable "data" property. Several prior questions have helped tremendously, but I'm still lacking some implementation details. I'm trying to avoid using variable sized arrays, and just use a vector. But I can't get it to be transmitted correctly, and I believe it's somewhere during serialization. Now for some code. Packet Header class Packet { public: void* Serialize(); bool Deserialize(void *message); unsigned int sender_id; unsigned int sequence_number; std::vector<char> data; }; Packet ImpL typedef struct { unsigned int sender_id; unsigned int sequence_number; std::vector<char> data; } Packet; void* Packet::Serialize(int size) { Packet* p = (Packet *) malloc(8 + 30); p->sender_id = htonl(this->sender_id); p->sequence_number = htonl(this->sequence_number); p->data.assign(size,'&'); //just for testing purposes } bool Packet::Deserialize(void *message) { Packet *s = (Packet*)message; this->sender_id = ntohl(s->sender_id); this->sequence_number = ntohl(s->sequence_number); this->data = s->data; } During execution, I simply create a packet, assign it's members, and send/receive accordingly. The above methods are only responsible for serialization. Unfortunately, the data never gets transferred. Couple of things to point out here. I'm guessing the malloc is wrong, but I'm not sure how else to compute it (i.e. what other value it would be). Other than that, I'm unsure of the proper way to use a vector in this fashion, and would love for someone to show me how (code examples please!) :) Edit: I've awarded the question to the most comprehensive answer regarding the implementation with a vector data property. Appreciate all the responses!

    Read the article

  • Design Technique: How to design a complex system for processing orders, products and units.

    - by Shyam
    Hi, Programming is fun: I learned that by trying out simple challenges, reading up some books and following some tutorials. I am able to grasp the concepts of writing with OO (I do so in Ruby), and write a bit of code myself. What bugs me though is that I feel re-inventing the wheel: I haven't followed an education or found a book (a free one that is) that explains me the why's instead of the how's, and I've learned from the A-team that it is the plan that makes it come together. So, armed with my nuby Ruby skills, I decided I wanted to program a virtual store. I figured out the following: My virtual Store will have: Products and Services Inventories Orders and Shipping Customers Now this isn't complex at all. With the help of some cool tools (CMapTools), I drew out some concepts, but quickly enough (thanks to my inferior experience in designing), my design started to bite me. My very first product-line were virtual "laptops". So, I created a class (Ruby): class Product attr_accessor :name, :price def initialize(name, price) @name = name @price = price end end which can be instantiated by doing (IRb) x = Product.new("Banana Pro", 250) Since I want my virtual customers to be able to purchase more than one product, or various types, I figured out I needed some kind of "Order" mechanism. class Order def initialize(order_no) @order_no = order_no @line_items = [] end def add_product(myproduct) @line_items << myproduct end def show_order() puts @order_no @line_items.each do |x| puts x.name.to_s + "\t" + x.price.to_s end end end that can be instantiated by doing (IRb) z = Order.new(1234) z.add_product(x) z.show_order Splendid, I have now a very simple ordering system that allows me to add products to an order. But, here comes my real question. What if I have three models of my product (economy, business, showoff)? Or have my products be composed out of separate units (bigger screen, nicer keyboard, different OS)? Surely I could make them three separate products, or add complexity to my product class, but I am looking for are best practices to design a flexible product object that can be used in the real world, to facilitate a complex system. My apologies if my grammar and my spelling are with error, as english is not my first language and I took the time to check as far I could understand and translate properly! Thank you for your answers, comments and feedback!

    Read the article

  • Java - is this an idiom or pattern, behavior classes with no state

    - by Berlin Brown
    I am trying to incorporate more functional programming idioms into my java development. One pattern that I like the most and avoids side effects is building classes that have behavior but they don't necessarily have any state. The behavior is locked into the methods but they only act on the parameters passed in. The code below is code I am trying to avoid: public class BadObject { private Map<String, String> data = new HashMap<String, String>(); public BadObject() { data.put("data", "data"); } /** * Act on the data class. But this is bad because we can't * rely on the integrity of the object's state. */ public void execute() { data.get("data").toString(); } } The code below is nothing special but I am acting on the parameters and state is contained within that class. We still may run into issues with this class but that is an issue with the method and the state of the data, we can address issues in the routine as opposed to not trusting the entire object. Is this some form of idiom? Is this similar to any pattern that you use? public class SemiStatefulOOP { /** * Private class implies that I can access the members of the <code>Data</code> class * within the <code>SemiStatefulOOP</code> class and I can also access * the getData method from some other class. * * @see Test1 * */ class Data { protected int counter = 0; public int getData() { return counter; } public String toString() { return Integer.toString(counter); } } /** * Act on the data class. */ public void execute(final Data data) { data.counter++; } /** * Act on the data class. */ public void updateStateWithCallToService(final Data data) { data.counter++; } /** * Similar to CLOS (Common Lisp Object System) make instance. */ public Data makeInstance() { return new Data(); } } // End of Class // Issues with the code above: I wanted to declare the Data class private, but then I can't really reference it outside of the class: I can't override the SemiStateful class and access the private members. Usage: final SemiStatefulOOP someObject = new SemiStatefulOOP(); final SemiStatefulOOP.Data data = someObject.makeInstance(); someObject.execute(data); someObject.updateStateWithCallToService(data);

    Read the article

  • L-Soft LISTSERV TCPGUI Interface for PHP Creation

    - by poolnoodl
    I'm trying to use LISTSERV's "API" in PHP. L-Soft calls this TCPGUI, and essentially, you can request data like over Telnet. To do this, I'm using PHP's TCP socket functions. I've seen this done in other languages but can't quite convert it to PHP. I can connect, I can change set ASCII or BINARY mode. But I can never quite craft the header packet the way I need to authenticate, so I'm thinking I'm messing up my conversion. C: http://www.lsoft.com/manuals/16.0/htmlhelp/advanced%20topics/TCPGUI.html#2334328 $origin = '[email protected]'; $pwd = 'password'; $host = "example.com"; $port = 2306; $email = "[email protected]"; $list = "mailinglist"; $command = "Query $list FOR $email"; $fp = stream_socket_client("tcp://$host:$port", $errno, $errstr, 30); $cmd = $command . " PW=" . $pwd; $len = strlen($cmd); $orglen = strlen($origin); $n = $len + $orglen + 1; $headerPacket[0] = "1"; $headerPacket[1] = "B"; $headerPacket[2] = "\r"; $headerPacket[3] = "\n"; $headerPacket[4] = ord($n / 256); $headerPacket[5] = ord($n + 255); $headerPacket[6] = ord($orglen); for ($i = 0; $i < $orglen; $i++) { $headerPacket[$i + 7] = ord($origin[$i]); } for ($i = 0; $i < $len; $i++) { $cmdPacket[$i] = ord($cmd[$i]); } fwrite($fp, implode($headerPacket)); while (!feof($fp)) { echo fgets($fp, 1024); } Any thoughts on where I'm going wrong? I'd much appreciate it if anyone could point me toward some code to do this, days of googling and searching here on SO has only lead me to examples in other languages. Of course, if you know C (or Java or Perl as linked below in my comment to bypass the spam filter), PHP, and socket programming fairly well, you could probably rewrite the whole of the code in an hour, maybe a few minutes. You'd have my eternal thanks for that.

    Read the article

  • Derived template override return type of member function C++

    - by Ruud v A
    I am writing matrix classes. Take a look at this definition: template <typename T, unsigned int dimension_x, unsigned int dimension_y> class generic_matrix { ... generic_matrix<T, dimension_x - 1, dimension_y - 1> minor(unsigned int x, unsigned int y) const { ... } ... } template <typename T, unsigned int dimension> class generic_square_matrix : public generic_matrix<T, dimension, dimension> { ... generic_square_matrix(const generic_matrix<T, dimension, dimension>& other) { ... } ... void foo(); } The generic_square_matrix class provides additional functions like matrix multiplication. Doing this is no problem: generic_square_matrix<T, 4> m = generic_matrix<T, 4, 4>(); It is possible to assign any square matrix to M, even though the type is not generic_square_matrix, due to the constructor. This is possible because the data does not change across children, only the supported functions. This is also possible: generic_square_matrix<T, 4> m = generic_square_matrix<T, 5>().minor(1,1); Same conversion applies here. But now comes the problem: generic_square_matrix<T, 4>().minor(1,1).foo(); //problem, foo is not in generic_matrix<T, 3, 3> To solve this I would like generic_square_matrix::minor to return a generic_square_matrix instead of a generic_matrix. The only possible way to do this, I think is to use template specialisation. But since a specialisation is basically treated like a separate class, I have to redefine all functions. I cannot call the function of the non-specialised class as you would do with a derived class, so I have to copy the entire function. This is not a very nice generic-programming solution, and a lot of work. C++ almost has a solution for my problem: a virtual function of a derived class, can return a pointer or reference to a different class than the base class returns, if this class is derived from the class that the base class returns. generic_square_matrix is derived from generic_matrix, but the function does not return a pointer nor reference, so this doesn't apply here. Is there a solution to this problem (possibly involving an entirely other structure; my only requirements are that the dimensions are a template parameter and that square matrices can have additional functionality). Thanks in advance, Ruud

    Read the article

  • What's the purpose of arrays starting with nonzero index?

    - by helios35
    I tried to find answers, but all I got was answers on how to realize arrays starting with nonzero indexes. Some languages, such as pascal, provide this by default, e.g., you can create an array such as var foobar: array[1..10] of string; I've always been wondering: Why would you want to have the array index not to start with 0? I guess it may be more familiar for beginners to have arrays starting with 1 and the last index being the size of the array, but on a long-term basis, programmers should get used to values starting with 0. Another purpose I could think of: In some cases, the index could actually represent something thats contained in the respective array-entry. e.g., you want to get all capital letters in an array, it may be handy to have an index being the ASCII-Code of the respective letter. But its pretty easy just to subtract a constant value. In this example, you could (in C) simply do something like this do get all capital letters and access the letter with ascii-code 67: #define ASCII_SHIFT 65 main() { int capital_letters[26]; int i; for (i=0; i<26; i++){ capital_letters[i] = i+ASCII_SHIFT; } printf("%c\n", capital_letters[67-ASCII_SHIFT]); } Also, I think you should use hash tables if you want to access entries by some sort of key. Someone might retort: Why should the index always start with 0? Well, it's a hell of a lot simpler this way. You'll be faster when you just have to type one index when declaring an array. Also, you can always be sure that the first entry is array[0] and the last one is array[length_of_array-1]. It is also common that other data structures start with 0. e.g., if you read a binary file, you start with the 0th byte, not the first. Now, why do some programming languages have this "feature" and why do some people ask how to achieve this in languages such as C/C++?, is there any situation where an array starting with a nonzero index is way more useful, or even, something simply cannot be done with an array starting at 0?

    Read the article

  • XNA: Rotating Bones

    - by MLM
    XNA 4.0 I am trying to learn how to rotate bones on a very simple tank model I made in Cinema 4D. It is rigged by 3 bones, Root - Main - Turret - Barrel I have binded all of the objects to the bones so that all translations/rotations work as planned in C4D. I exported it as .fbx I based my test project after: http://create.msdn.com/en-US/education/catalog/sample/simple_animation I can build successfully with no errors but all the rotations I try to do to my bones have no effect. I can transform my Root successfully using below but the bone transforms have no effect: myModel.Root.Transform = world; Matrix turretRotation = Matrix.CreateRotationY(MathHelper.ToRadians(37)); Matrix barrelRotation = Matrix.CreateRotationX(barrelRotationValue); MainBone.Transform = MainTransform; TurretBone.Transform = turretRotation * TurretTransform; BarrelBone.Transform = barrelRotation * BarrelTransform; I am wondering if my model is just not right or something important I am missing in the code. Here is my Game1.cs using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace ModelTesting { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; float aspectRatio; Tank myModel; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here myModel = new Tank(); base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); // TODO: use this.Content to load your game content here myModel.Load(Content); aspectRatio = graphics.GraphicsDevice.Viewport.AspectRatio; } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // TODO: Add your update logic here float time = (float)gameTime.TotalGameTime.TotalSeconds; // Move the pieces /* myModel.TurretRotation = (float)Math.Sin(time * 0.333f) * 1.25f; myModel.BarrelRotation = (float)Math.Sin(time * 0.25f) * 0.333f - 0.333f; */ base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); // Calculate the camera matrices. float time = (float)gameTime.TotalGameTime.TotalSeconds; Matrix rotation = Matrix.CreateRotationY(MathHelper.ToRadians(45)); Matrix view = Matrix.CreateLookAt(new Vector3(2000, 500, 0), new Vector3(0, 150, 0), Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, graphics.GraphicsDevice.Viewport.AspectRatio, 10, 10000); // TODO: Add your drawing code here myModel.Draw(rotation, view, projection); base.Draw(gameTime); } } } And here is my tank class: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace ModelTesting { public class Tank { Model myModel; // Array holding all the bone transform matrices for the entire model. // We could just allocate this locally inside the Draw method, but it // is more efficient to reuse a single array, as this avoids creating // unnecessary garbage. public Matrix[] boneTransforms; // Shortcut references to the bones that we are going to animate. // We could just look these up inside the Draw method, but it is more // efficient to do the lookups while loading and cache the results. ModelBone MainBone; ModelBone TurretBone; ModelBone BarrelBone; // Store the original transform matrix for each animating bone. Matrix MainTransform; Matrix TurretTransform; Matrix BarrelTransform; // current animation positions float turretRotationValue; float barrelRotationValue; /// <summary> /// Gets or sets the turret rotation amount. /// </summary> public float TurretRotation { get { return turretRotationValue; } set { turretRotationValue = value; } } /// <summary> /// Gets or sets the barrel rotation amount. /// </summary> public float BarrelRotation { get { return barrelRotationValue; } set { barrelRotationValue = value; } } /// <summary> /// Load the model /// </summary> public void Load(ContentManager Content) { // TODO: use this.Content to load your game content here myModel = Content.Load<Model>("Models\\simple_tank02"); MainBone = myModel.Bones["Main"]; TurretBone = myModel.Bones["Turret"]; BarrelBone = myModel.Bones["Barrel"]; MainTransform = MainBone.Transform; TurretTransform = TurretBone.Transform; BarrelTransform = BarrelBone.Transform; // Allocate the transform matrix array. boneTransforms = new Matrix[myModel.Bones.Count]; } public void Draw(Matrix world, Matrix view, Matrix projection) { myModel.Root.Transform = world; Matrix turretRotation = Matrix.CreateRotationY(MathHelper.ToRadians(37)); Matrix barrelRotation = Matrix.CreateRotationX(barrelRotationValue); MainBone.Transform = MainTransform; TurretBone.Transform = turretRotation * TurretTransform; BarrelBone.Transform = barrelRotation * BarrelTransform; myModel.CopyAbsoluteBoneTransformsTo(boneTransforms); // Draw the model, a model can have multiple meshes, so loop foreach (ModelMesh mesh in myModel.Meshes) { // This is where the mesh orientation is set foreach (BasicEffect effect in mesh.Effects) { effect.World = boneTransforms[mesh.ParentBone.Index]; effect.View = view; effect.Projection = projection; effect.EnableDefaultLighting(); } // Draw the mesh, will use the effects set above mesh.Draw(); } } } }

    Read the article

< Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >