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• Organising files and classes in XCode (iPhone application)

  - by pulegium

  It's a generic question and really a newbie one too, so bear with me... I'm playing with some iPhone development, and trying to create a simple "flip type" application. Nothing sophisticated, let's say on the flip side is a short application summary, bit like 'help' and on the main screen is a simple board game, let's say tic-tac-toe or similar. Now, XCode has generated me 'Main View', 'Flipside View' and 'Application Delegate' folders, with default template files in them. Now the question is where do I create appropriate 'MVC' classes? Let's say (V)iew classes are going to be the ones that have been automatically created. So the Flipside view class is responsible for generating text/images etc on the 'help' view. 'Main View' class is what draws the items on the table and updates the counters, etc. Where should I place the 'controller' class? And also, should it only be dealing with proxying only to the model? According to this the controller method is called from the view and manipulates the method classes. Similarly, the results from model are passed back to the view class by the controller issuing the calls to appropriate view methods. Similarly, where does the model class go? or should I just create a new folder for each, controller and model class files? What I'm after is the best practices, or just a short description how people normally structure their applications. I know it's very specific and also undefined... I came from Django background, so the way stuff is organised there is slightly different. Hope this makes sense, sorry if it's all bit vague, but I have to start somewhere :) And yes I've read quite few docs on the apple developer site, but trouble is that the documents are either going into too much detail about the language/framework/etc and the examples are way too simplistic. Actually, this leads me to the final question, has anyone know any good example of relatively complete application tutorial which I could use as a reference in organising my files?...

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• How to limit TCP writes to particular size and then block untlil the data is read

  - by ustulation

  {Qt 4.7.0 , VS 2010} I have a Server written in Qt and a 3rd party client executable. Qt based server uses QTcpServer and QTcpSocket facilities (non-blocking). Going through the articles on TCP I understand the following: the original implementation of TCP mentioned the negotiable window size to be a 16-bit value, thus maximum being 65535 bytes. But implementations often used the RFC window-scale-extension that allows the sliding window size to be scalable by bit-shifting to yield a maximum of 1 gigabyte. This is implementation defined. This could have resulted in majorly different window sizes on receiver and sender end as the server uses Qt facilities without hardcoding any window size limit. Client 1st asks for all information it can based on the previous messages from the server before handling the new (accumulating) incoming messages. So at some point Server receives a lot of messages each asking for data of several MB's. This the server processes and puts it into the sender buffer. Client however is unable to handle the messages at the same pace and it seems that client’s receiver buffer is far smaller (65535 bytes maybe) than sender’s transmit window size. The messages thus get accumulated at sender’s end until the sender’s buffer is full too after which the TCP writes on sender would block. This however does not happen as sender buffer is much larger. Hence this manifests as increase in memory consumption on the sender’s end. To prevent this from happening, I used Qt’s socket’s waitForBytesWritten() with timeout set to -1 for infinite waiting period. This as I see from the behaviour blocks the thread writing TCP data until the data has actually been sensed by the receiver’s window (which will happen when earlier messages have been processed by the client at application level). This has caused memory consumption at Server end to be almost negligible. is there a better alternative to this (in Qt) if i want to restrict the memory consumption at server end to say x MB's? Also please point out if any of my understandings is incorrect.

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• Is there a way to receive data as unsigned char over UDP on Qt?

  - by user269037

  I need to send floating point numbers using a UDP connection to a Qt application. Now in Qt the only function available is qint64 readDatagram ( char * data, qint64 maxSize, QHostAddress * address = 0, quint16 * port = 0 ) which accepts data in the form of signed character buffer. I can convert my float into a string and send it but it will obviously not be very efficient converting a 4 byte float into a much longer sized character buffer. I got hold of these 2 functions to convert a 4 byte float into an unsinged 32 bit integer to transfer over network which works fine for a simple C++ UDP program but for Qt I need to receive the data as unsigned char. Is it possible to avoid converting the floatinf point data into a string and then sending it? uint32_t htonf(float f) { uint32_t p; uint32_t sign; if (f < 0) { sign = 1; f = -f; } else { sign = 0; } p = ((((uint32_t)f)&0x7fff)<<16) | (sign<<31); // Whole part and sign. p |= (uint32_t)(((f - (int)f) * 65536.0f))&0xffff; // Fraction. return p; } float ntohf(uint32_t p) { float f = ((p>>16)&0x7fff); // Whole part. f += (p&0xffff) / 65536.0f; // Fraction. if (((p>>31)&0x1) == 0x1) { f = -f; } // Sign bit set. return f; }

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• .Net Hash Codes no longer persistent?

  - by RobV

  I have an API where various types have custom hash codes. These hash codes are based on getting the hash of a string representation of the object in question. Various salting techniques are used so that as far as possible Hash Codes do not collide and that Objects of different types with equivalent string representations have different Hash Codes. Obviously since the Hash Codes are based on strings there are some collisions (infinite strings vs the limited range of 32 bit integers). I use hashes based on string representations since I need the hashes to persist over sessions and particularly for use in database storage of objects. Suddenly today my code has started generating different hash codes for Objects which is breaking all kinds of things. It was working earlier today and I haven't touched any of the code involved in Hash Code generation. I'm aware that the .Net documentation allows for implementation of hash codes between .Net framework versions to change (and between 32 and 64 bit versions) but I haven't changed the framework version and there has been no framework updates recently as far as I can remember Any ideas because this seems really weird? Edit Hash Codes are generated like follows: //Compute Hash Code this._hashcode = (this._nodetype + this.ToString() + PlainLiteralHashCodeSalt).GetHashCode();

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• Number of characters recommended for a statement

  - by liaK

  Hi, I have been using Qt 4.5 and so do C++. I have been told that it's a standard practice to maintain the length of each statement in the application to 80 characters. Even in Qt creator we can make a right border visible so that we can know whether we are crossing the 80 characters limit. But my question is, Is it really a standard being followed? Because in my application, I use indenting and all, so it's quite common that I cross the boundary. Other cases include, there might be a error statement which will be a bit explanatory one and which is in an inner block of code, so it too will cross the boundary. Usually my variable names look bit lengthier so as to make the names meaningful. When I call the functions of the variable names, again I will cross. Function names will not be in fewer characters either. I agree a horizontal scroll bar shows up and it's quite annoying to move back and forth. So, for function calls including multiple arguments, when the boundary is reached I will make the forth coming arguments in the new line. But besides that, for a single statement (for e.g a very long error message which is in double quotes " " or like longfun1()->longfun2()->...) if I use an \ and split into multiple lines, the readability becomes very poor. So is it a good practice to have those statement length restrictions? If this restriction in statement has to be followed? I don't think it depends on a specific language anyway. I added C++ and Qt tags since if it might. Any pointers regarding this are welcome.

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• rake db:migrate fails when trying to do inserts

  - by anthony

  I'm trying to get a database populate so I can begin working on a project. THis project is already built and I'm being brought in to helpwith front-end work. Problem is I can't get rake db:migrate to do any inserts. Every time I run rake db:migrate I get this: ... == 20081220084043 CreateTimeDimension: migrating ============================== -- create_table(:time_dimension) - 0.0870s INSERT time_dimension(time_key, year, month, day, day_of_week, weekend, quarter) VALUES(20080101, 2008, 1, 1, 'Tuesday', false, 1) rake aborted! Could not load driver (uninitialized constant Mysql::Driver) ... I'm building on a MBP with Snow Leopard. I've installed XCode from the disk that comes with the mac. I've updated ruby, installed rails and all the needed gems. I have the 64 bit version of MySQL installed. I've tried the 32 bit version of MySQL and I've even tried installing from macports (via http://www.robbyonrails.com/articles/2010/02/08/installing-ruby-on-rails-passenger-postgresql-mysql-oh-my-zsh-on-snow-leopard-fourth-edition) The mysql gemis installed using: sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/path/to/mysql/bin/mysql_config the migrate creates the tables just fine but it dies every. single. time. it trys an insert. Any help would be great

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• Can the size of a structure change after compiled?

  - by Sarah Altiva

  Hi, suppose you have the following structure: #include <windows.h> // BOOL is here. #include <stdio.h> typedef struct { BOOL someBool; char someCharArray[100]; int someIntValue; BOOL moreBools, anotherOne, yetAgain; char someOthercharArray[23]; int otherInt; } Test; int main(void) { printf("Structure size: %d, BOOL size: %d.\n", sizeof(Test), sizeof(BOOL)); } When I compile this piece of code in my machine (32-bit OS) the output is the following: Structure size: 148, BOOL size: 4. I would like to know if, once compiled, these values may change depending on the machine which runs the program. E.g.: if I ran this program in a 64-bit machine, would the output be the same? Or once it's compiled it'll always be the same? Thank you very much, and forgive me if the answer to this question is obvious...

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• C++ Printing: Printer jams, what am I doing wrong?

  - by Kleas

  I have a problem with printing in C++. As far as I know, this code used to work on my previous printer, but ever since I got another one (an HP C7280) it started giving problems. Whenever I try to print anything, even an empty page, the page JAMS the printer. I have to manualy remove the page from the printer. I have no clue why this is happening. Am I doing something wrong, is it a driver problem, are there better ways to print in C++? I am using Windows 7 64 bit, but this problem also presented itself when I was using Windows Vista 64 bit. I use the following code: PRINTDLG pd; ZeroMemory(&pd, sizeof(pd)); pd.lStructSize = sizeof(pd); pd.hwndOwner = mainWindow; pd.hDevMode = NULL; pd.hDevNames = NULL; pd.Flags = PD_USEDEVMODECOPIESANDCOLLATE | PD_RETURNDC; pd.nCopies = 1; pd.nMinPage = 1; pd.nMaxPage = 0xFFFF; if (PrintDlg(&pd)==TRUE) { DOCINFO di; di.cbSize = sizeof(DOCINFO); di.lpszDocName = "Rumitec en Roblaco Print"; di.lpszOutput = (LPTSTR)NULL; di.fwType = 0; // Start printing StartDoc(pd.hDC, &di); StartPage(pd.hDC); initPrinter(pd.hDC); // ... // Do some drawing // ... // End printing EndPage(pd.hDC); EndDoc(pd.hDC); DeleteDC(pd.hDC); } Am I doing something wrong? Alternatively, is there a better, easier, more modern way to do it?

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• Logic: Best way to sample & count bytes of a 100MB+ file

  - by Jami

  Let's say I have this 170mb file (roughly 180 million bytes). What I need to do is to create a table that lists: all 4096 byte combinations found [column 'bytes'], and the number of times each byte combination appeared in it [column 'occurrences'] Assume two things: I can save data very fast, but I can update my saved data very slow. How should I sample the file and save the needed information? Here're some suggestions that are (extremely) slow: Go through each 4096 byte combinations in the file, save each data, but search the table first for existing combinations and update it's values. this is unbelievably slow Go through each 4096 byte combinations in the file, save until 1 million rows of data in a temporary table. Go through that table and fix the entries (combine repeating byte combinations), then copy to the big table. Repeat going through another 1 million rows of data and repeat the process. this is faster by a bit, but still unbelievably slow This is kind of like taking the statistics of the file. NOTE: I know that sampling the file can generate tons of data (around 22Gb from experience), and I know that any solution posted would take a bit of time to finish. I need the most efficient saving process

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• How to split this string and identify first sentence after last '*'?

  - by DaveDev

  I have to get a quick demo for a client, so this is a bit hacky. Please don't flame me too much! :-) I'm getting a string similar to the following back from the database: The object of the following is to do: * blah 1 * blah 2 * blah 3 * blah 4. Some more extremely uninteresting text. Followed by yet another sentence full of extrememly uninteresting text. Thankfully this is the last sentence. I need to format this so that each * represents a bullet point, and the sentence after the last * goes onto a new line, ideally as follows: The object of the following is to do: blah 1 (StackOverflow wants to add bullet points here, but I just need '*') blah 2 blah 3 blah 4. Some more extremely uninteresting text. Followed by yet another sentence full of extrememly uninteresting text. Thankfully this is the last sentence. It's easy enough to split the string by the * character and replace that with <br /> *. I'm using the following for that: string description = GetDescription(); description = description.Replace("*", "<br />*"); // it's going onto a web page. but the result this gives me is: The object of the following is to do: blah 1 blah 2 blah 3 blah 4. Some more extremely uninteresting text. Followed by yet another sentence full of extrememly uninteresting text. Thankfully this is the last sentence. I'm having a bit of difficulty identifying the fist sentence after the last '*' so I can put a break there too. Can somebody show me how to do this?

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• Timing issues with playback of the HTML5 Audio API

  - by pat

  I'm using the following code to try to play a sound clip with the HTML5 Audio API: HTMLAudioElement.prototype.playClip = function(startTime, stopTime) { this.stopTime = stopTime; this.currentTime = startTime; this.play(); $(this).bind('timeupdate', function(){ if (this.ended || this.currentTime >= stopTime) { this.pause(); $(this).unbind('timeupdate'); } }); } I utilize this new playClip method as follows. First I have a link with some data attributes: <a href=# data-stop=1.051 data-start=0.000>And then I was thinking,</a> And finally this bit of jQuery which runs on $(document).ready to hook up a click on the link with the playback: $('a').click(function(ev){ $('a').click(function(ev){ var start = $(this).data('start'), stop = $(this).data('stop'), audio = $('audio').get(0), $audio = $(audio); ev.preventDefault(); audio.playClip(start,stop); }) This approach seems to work, but there's a frustrating bug: sometimes, the playback of a given clip plays beyond the correct data-stop time. I suspect it could have something to do with the timing of the timeupdate event, but I'm no JS guru and I don't know how to begin debugging the problem. Here are a few clues I've gathered: The same behavior appears to come up in both FF and Chrome. The playback of a given clip actually seems to vary a bit -- if I play the same clip a couple times in a row, it may over-play a different amount of time on each playing. Is the problem here the inherent accuracy of the Audio API? My app needs milliseconds. Is there a problem with the way I'm using jQuery to bind and unbind the timeupdate event? I tried using the jQuery-less approach with addEventListener but I couldn't get it to work. Thanks in advance, I would really love to know what's going wrong.

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• ASP.NET DynamicData: Whats happening during an update?

  - by Jens A.

  I am using ASP.NET DynamicData (based on LINQ to SQL) on my site for basic scaffolding. On one table I have added additional properties, that are not stored in the table, but are retrieved from somewhere else. (Profile information for a user account, in this case). They are displayed just fine, but when editing these values and pressing "Update", they are not changed. Here's what the properties look like, the table is the standard aspnet_Users table: public String Address { get { UserProfile profile = UserProfile.GetUserProfile(UserName); return profile.Address; } set { UserProfile profile = UserProfile.GetUserProfile(UserName); profile.Address = value; profile.Save(); } } When I fired up the debugger, I've noticed that for each update the set accessor is called three times. Once with the new value, but on a newly created instance of user, then once with the old value, again on an new instance, and finally with the old value on the existing instance. Wondering a bit, I checked with the properties created by the designer, and they, too, are called three times in (almost) the same fashion. The only difference is, that the last call contains the new value for the property. I am a bit stumped here. Why three times, and why are my new properties behaving differently? I'd be grateful for any help on that matter! =)

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• Handling primary key duplicates in a data warehouse load

  - by Meff

  I'm currently building an ETL system to load a data warehouse from a transactional system. The grain of my fact table is the transaction level. In order to ensure I don't load duplicate rows I've put a primary key on the fact table, which is the transaction ID. I've encountered a problem with transactions being reversed - In the transactional database this is done via a status, which I pick up and I can work out if the transaction is being done, or rolled back so I can load a reversal row in the warehouse. However, the reversal row will have the same transaction ID and so I get a primary key violation. I've solved this for now by negating the primary key, so transaction ID 1 would be a payment, and transaction ID -1 (In the warehouse only) would be the reversal. I have considered an alternative of generating a BIT column, where 0 is normal and 1 is reversal, then making the PK the transaction ID and the BIT column. My question is, is this a good practice, and has anyone else encountered anything like this? For reference, this is a payment processing system, so values will not be modified, so there will only ever be transactions and reversals.

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• Where to turn upon realizing I can't program my way out of a paper bag?

  - by luminarious

  I have no job and just enough money to get by until April or so. While looking for work, I figured I might as well go through with a pet project, a browser based card game. Make it nice and free, collect donations and maybe earn enough for a movie ticket to escape reality for a while. I have dabbled in web development a bit. I can make simple stuff happen with JS/PHP if I follow tutorials. I designed my own art blog's template - http://luminarious.tumblr.com. I can visualise the game working in my head, flowcharts and everything. But then I tried to go deeper with Javascript and almost had an aneurysm before understanding what a closure is. Wether I suck at learning, have ADD or fail epically at productivity, I have not got much done. Coming up with ideas, screen mock-ups and so forth was very enjoyable, but actual implementation.. not so much. In fact, I cry a bit every time I think about the time someone competent could have finished this in. I'd like to excuse myself with my ENTP personality type, but that hardly solves anything. Rather, I'd like to know to get from A (bunch of ideas with little semblance to a web app) to B (something to proudly show others) while being unable to pay anyone? Are there any secret techniques for learning? Is there any way to get mentoring or code review? Is there anyone with too much free time willing to code for me? How to trust someone to not steal my code when I ask for assistance? Is there anything I should have asked instead of any of those?

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• Android Plugin for Eclipse problem

  - by tbneff

  I am using a laptop with Windows 7 Home Prem x64. I have installed Java JDK1.6.0_18 and Eclipse Gallileo. I have downloaded and installed the latest version of Android SDK with several Platforms loaded and a AVD defined. I can install the Android Eclipse plugin from the remote site stated in the instructions. The plugin installation performs without any errors and I can verify that the plugins are indeed installed. My problem begins when I go to Windows - Preferences, there is no Android section to configure. And when I go to File - New - Project, there is no Android Project to choose. I have uninstalled the plugin and reinstalled at least 10 times, trying different things and still no luck. I originally had the 64 bit version of the JDK installed, but removed it and installed the 32 bit version. Has anyone heard of this type of problem? Is it because I am using Windows 7? Thanks for any help. tbneff

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• Ruby on Rails or PHP... Somehow uncertain

  - by Clamm

  Hi everybody... I've been thinking about this a long time now but i wanna hear your opinion because i always received the ebst answers here. So in advance... thank you guys. Right now i have to make this decision: Shift a prototype webservice to production quality. Choose either Ruby or PHP... (Background: A friend of mine is joining the project and prefers rails) I've already played around a bit with RoR (only basic stuff) but i am really disappointed about the documentation of Rails and Ruby. In relation to PHP i find only fragments or hard to use references. At the end i am a bit scared. I dont wanna waste my time realizing that i am not capable of doing s.th in Ruby what i could with PHP. Maybe only because i am too stupid and don't find a proper explanation ;-) Did anyone experience this shift and can tell me how easy/hard it was to switch from PHP to Ruby? E.G. would you recommend programming it in PHP and using MVC as a base pattern? Thanks for your opinion!!!

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• Question about array subscripting in C#

  - by Michael J

  Back in the old days of C, one could use array subscripting to address storage in very useful ways. For example, one could declare an array as such. This array represents an EEPROM image with 8 bit words. BYTE eepromImage[1024] = { ... }; And later refer to that array as if it were really multi-dimensional storage BYTE mpuImage[2][512] = eepromImage; I'm sure I have the syntax wrong, but I hope you get the idea. Anyway, this projected a two dimension image of what is really single dimensional storage. The two dimensional projection represents the EEPROM image when loaded into the memory of an MPU with 16 bit words. In C one could reference the storage multi-dimensionaly and change values and the changed values would show up in the real (single dimension) storage almost as if by magic. Is it possible to do this same thing using C#? Our current solution uses multiple arrays and event handlers to keep things synchronized. This kind of works but it is additional complexity that we would like to avoid if there is a better way.

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• md5_file() not working with IP addresses?

  - by Rob

  Here is my code relating to the question: $theurl = trim($_POST['url']); $md5file = md5_file($theurl); if ($md5file != '96a0cec80eb773687ca28840ecc67ca1') { echo 'Hash doesn\'t match. Incorrect file. Reupload it and try again'; When I run this script, it doesn't even output an error. It just stops. It loads for a bit, and then it just stops. Further down the script I implement it again, and it fails here, too: while($row=mysql_fetch_array($execquery, MYSQL_ASSOC)){ $hash = @md5_file($row['url']); $url = $row['url']; mysql_query("UPDATE urls SET hash='" . $hash . "' WHERE url='" . $url . "'") or die("MYSQL is indeed gay: ".mysql_error()); if ($hash != '96a0cec80eb773687ca28840ecc67ca1'){ $status = 'down'; }else{ $status = 'up'; } mysql_query("UPDATE urls SET status='" . $status . "' WHERE url='" . $url . "'") or die("MYSQL is indeed gay: ".mysql_error()); } And it checks all the URL's just fine, until it gets to one with an IP instead of a domain, such as: http://188.72.215.195/config.php In which, again, the script then just loads for a bit, and then stops. Any help would be much appreciated, if you need any more information just ask.

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• Coding the R-ight way - avoiding the for loop

  - by mropa

  I am going through one of my .R files and by cleaning it up a little bit I am trying to get more familiar with writing the code the r-ight way. As a beginner, one of my favorite starting points is to get rid of the for() loops and try to transform the expression into a functional programming form. So here is the scenario: I am assembling a bunch of data.frames into a list for later usage. dataList <- list (dataA, dataB, dataC, dataD, dataE ) Now I like to take a look at each data.frame's column names and substitute certain character strings. Eg I like to substitute each "foo" and "bar" with "baz". At the moment I am getting the job done with a for() loop which looks a bit awkward. colnames(dataList[[1]]) [1] "foo" "code" "lp15" "bar" "lh15" colnames(dataList[[2]]) [1] "a" "code" "lp50" "ls50" "foo" matchVec <- c("foo", "bar") for (i in seq(dataList)) { for (j in seq(matchVec)) { colnames (dataList[[i]])[grep(pattern=matchVec[j], x=colnames (dataList[[i]]))] <- c("baz") } } Since I am working here with a list I thought about the lapply function. My attempts handling the job with the lapply function all seem to look alright but only at first sight. If I write f <- function(i, xList) { gsub(pattern=c("foo"), replacement=c("baz"), x=colnames(xList[[i]])) } lapply(seq(dataList), f, xList=dataList) the last line prints out almost what I am looking for. However, if i take another look at the actual names of the data.frames in dataList: lapply (dataList, colnames) I see that no changes have been made to the initial character strings. So how can I rewrite the for() loop and transform it into a functional programming form? And how do I substitute both strings, "foo" and "bar", in an efficient way? Since the gsub() function takes as its pattern argument only a character vector of length one.

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• hash fragments and collisions cont.

  - by Mark

  For this application I've mine I feel like I can get away with a 40 bit hash key, which seems awfully low, but see if you can confirm my reasoning (I want a small key because I want a small filename and the key will be converted to a filename): (Note: only accidental collisions a concern - no security issues.) A key point here is that the population in question is divided into groups, and a collision is only relevant if it occurs within the same group. A "group" is a directory on a user's system (the contents of files are hashed and a collision is only relevant if it occurs for files within the same directory). So with speculating roughly 100,000 potential users, say 2^17, that corresponds to 2^18 "groups" assuming 2 directories per user on average. So with a 40 bit key I can expect 2^(20+9) files created (among all users) before a collision occurs for some user somewhere. (Or IOW 2^((40+18)/2), due to the "birthday effect".) That's an average 4096 unique files created per user, for 2^17 users, before a single collision occurs for some user somewhere. And then that long again before another collision occurs somewhere (right?)

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• Patterns and Libraries for working with raw UI values.

  - by ProfK

  By raw values, I mean the application level values provided by UI controls, such as the Text property on a TextBox. Too often I find myself writing code to check and parse such values before they get used as a business level value, e.g. PaymentTermsNumDays. I've mitigated a lot of the spade work with rough and ready extension methods like String.ToNullableInt, but we all know that just isn't right. We can't put the whole world on String's shoulders. Do I look at tasking my UI to provide business values, using a ruleset pushed out from the server app, or open my business objects up a bit to do the required sanitising etc. as they required? Neither of these approaches sits quite right with me; the first seems closer to ideal, but quite a bit of work, while the latter doesn't show much respect to the business objects' single responsibility. The responsibilities of the UI are a closer match. Between these extremes, I could also just implement another DTO layer, an IoC container with sanitising and parsing services, derive enhanced UI controls, or stick to copy and paste inline drudgery.

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• Image resizing efficiency in C# and .NET 3.5

  - by Matthew Nichols

  I have written a web service to resize user uploaded images and all works correctly from a functional point of view, but it causes CPU usage to spike every time it is used. It is running on Windows Server 2008 64 bit. I have tried compiling to 32 and 64 bit and get about the same results. The heart of the service is this function: private Image CreateReducedImage(Image imgOrig, Size NewSize) { var newBM = new Bitmap(NewSize.Width, NewSize.Height); using (var newGrapics = Graphics.FromImage(newBM)) { newGrapics.CompositingQuality = CompositingQuality.HighSpeed; newGrapics.SmoothingMode = SmoothingMode.HighSpeed; newGrapics.InterpolationMode = InterpolationMode.HighQualityBicubic; newGrapics.DrawImage(imgOrig, new Rectangle(0, 0, NewSize.Width, NewSize.Height)); } return newBM; } I put a profiler on the service and it seemed to indicate the vast majority of the time is spent in the GDI+ library itself and there is not much to be gained in my code. Questions: Am I doing something glaringly inefficient in my code here? It seems to conform to the example I have seen. Are there gains to be had in using libraries other than GDI+? The benchmarks I have seen seem to indicate that GDI+ does well compare to other libraries but I didn't find enough of these to be confident. Are there gains to be had by using "unsafe code" blocks? Please let me know if I have not included enough of the code...I am happy to put as much up as requested but don't want to be obnoxious in the post.

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• Overlay an image over video using OpenGL ES shaders

  - by BlueVoodoo

  I am trying to understand the basic concepts of OpenGL. A week into it, I am still far from there. Once I am in glsl, I know what to do but I find getting there is the tricky bit. I am currently able to pass in video pixels which I manipulate and present. I have then been trying to add still image as an overlay. This is where I get lost. My end goal is to end up in the same fragment shader with pixel data from both my video and my still image. I imagine this means I need two textures and pass on two pixel buffers. I am currently passing the video pixels like this: glGenTextures(1, &textures[0]); //target, texture glBindTexture(GL_TEXTURE_2D, textures[0]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, buffer); Would I then repeat this process on textures[1] with the second buffer from the image? If so, do I then bind both GL_TEXTURE0 and GL_TEXTURE1? ...and would my shader look something like this? uniform sampler2D videoData; uniform sampler2D imageData; once I am in the shader? It seems no matter what combination I try, image and video always ends up being just video data in both these. Sorry for the many questions merged in here, just want to clear my many assumptions and move on. To clarify the question a bit, what do I need to do to add pixels from a still image in the process described? ("easy to understand" sample code or any types of hints would be appreciated).

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• Utility to indexing a directory?

  - by achacha

  Here is what I am trying to do: I have a directory (with sub-directories) with source files, I need to index them so I can find files fast (find as I type) so I can open them for compare/analysis. I don't want it to scan the content, just filename index for quick lookup. I do this when trying to determine if a class exists in a given tree (we maintain directory trees for each release which has a lot of files) and sometimes I want to quickly check files to see how something was implemented, etc. Most of these directories are on remote servers (sometimes on the other side of the world) or on a VM (which is on a server far away), so I only want to read the directory trees once, which is why running find every time is way too slow and doing 'find . foo.txt' and then searching that is a bit tedious. It's kind of like how "Find Resource" works in eclipse after it indexes all files, but it's a bit of a chore to import/remove directories into eclipse every time. Eclipse is also very slow when dealing with remote volumes. Any suggestions are appreciated :)

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• How to store arbitrary data for some HTML tags

  - by nickf

  I'm making a page which has some interaction provided by javascript. Just as an example: links which send an AJAX request to get the content of articles and then display that data in a div. Obviously in this example, I need each link to store an extra bit of information: the id of the article. The way I've been handling it in case was to put that information in the href link this: <a class="article" href="#5"> I then use jQuery to find the a.article elements and attach the appropriate event handler. (don't get too hung up on the usability or semantics here, it's just an example) Anyway, this method works, but it smells a bit, and isn't extensible at all (what happens if the click function has more than one parameter? what if some of those parameters are optional?) The immediately obvious answer was to use attributes on the element. I mean, that's what they're for, right? (Kind of). <a articleid="5" href="link/for/non-js-users.html"> In my recent question I asked if this method was valid, and it turns out that short of defining my own DTD (I don't), then no, it's not valid or reliable. A common response was to put the data into the class attribute (though that might have been because of my poorly-chosen example), but to me, this smells even more. Yes it's technically valid, but it's not a great solution. Another method I'd used in the past was to actually generate some JS and insert it into the page in a <script> tag, creating a struct which would associate with the object. var myData = { link0 : { articleId : 5, target : '#showMessage' // etc... }, link1 : { articleId : 13 } }; <a href="..." id="link0"> But this can be a real pain in butt to maintain and is generally just very messy. So, to get to the question, how do you store arbitrary pieces of information for HTML tags?

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