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• Simplifying data search using .NET

  - by Peter

  An example on the asp.net site has an example of using Linq to create a search feature on a Music album site using MVC. The code looks like this - public ActionResult Index(string movieGenre, string searchString) { var GenreLst = new List<string>(); var GenreQry = from d in db.Movies orderby d.Genre select d.Genre; GenreLst.AddRange(GenreQry.Distinct()); ViewBag.movieGenre = new SelectList(GenreLst); var movies = from m in db.Movies select m; if (!String.IsNullOrEmpty(searchString)) { movies = movies.Where(s => s.Title.Contains(searchString)); } if (!string.IsNullOrEmpty(movieGenre)) { movies = movies.Where(x => x.Genre == movieGenre); } return View(movies); } I have seen similar examples in other tutorials and I have tried them in a real-world business app that I develop/maintain. In practice this pattern doesn't seem to scale well because as the search criteria expands I keep adding more and more conditions which looks and feels unpleasant/repetitive. How can I refactor this pattern? One idea I have is to create a column in every table that is "searchable" which could be a computed column that concatenates all the data from the different columns (SQL Server 2008). So instead of having movie genre and title it would be something like. if (!String.IsNullOrEmpty(searchString)) { movies = movies.Where(s => s.SearchColumn.Contains(searchString)); } What are the performance/design/architecture implications of doing this? I have also tried using procedures that use dynamic queries but then I have just moved the ugliness to the database. E.g. CREATE PROCEDURE [dbo].[search_music] @title as varchar(50), @genre as varchar(50) AS -- set the variables to null if they are empty IF @title = '' SET @title = null IF @genre = '' SET @genre = null SELECT m.* FROM view_Music as m WHERE (title = @title OR @title IS NULL) AND (genre LIKE '%' + @genre + '%' OR @genre IS NULL) ORDER BY Id desc OPTION (RECOMPILE) Any suggestions? Tips?

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• Dell Inspiron7520 and ubntu 12.04 issues

  - by user91358

  I have a DELL Inspiron 7520 in the highest configuration: 3rd Generation Intel® Core™ i7-3612QM processor (6M Cache, up to 3.1 GHz) 15.6" Full High Definition (1080p) LED Display 8GB3 Dual Channel DDR3 SDRAM at 1600MHz 1TB 5400RPM SATA HDD + 32GB mSATA SSD w/Intel Smart Response Blu-ray Disc (BD) Combo (Reads BD and Writes to DVD/CD) AMD Radeon™ HD 7730M 2GB 6.09 lbs and I have installed Ubuntu 12.04 few days ago and I'm facing some issues: 1) sometimes the whole ntb freezes and I have to hold power button for 5 secs to shut it down. I think it is something with VGA and connected external monitor. I have read somewhere that it is already a reported bug, but what I am not sure about that it is doing sporadically. Sometimes it freezes right after I log in, sometime I ran few hours and then it freezes. I am using those proprietary drivers but I wasn't been able to install those with updates. 2) the next issue is the fan is quite noisy even when the ntb is almost Idle. (max 10% CPU usage). Can you recommend me some software which could do this power management to lower the noise? I have tried CPU frequency scaling indicator, but it seems that it has not any effects. 3) and issue no. 3: when I want to log out, restart or shutdown using the menu in upper right corner the upper and left trays disappear, but programs are still running and they won't close to complete log out or shutting down the OS. When I use the CLI command, it works fine. Thanks for any help you can provide.

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• Storing a pass-by-reference parameter as a pointer - Bad practice?

  - by Karl Nicoll

  I recently came across the following pattern in an API I've been forced to use: class SomeObject { public: // Constructor. SomeObject(bool copy = false); // Set a value. void SetValue(const ComplexType &value); private: bool m_copy; ComplexType *m_pComplexType; ComplexType m_complexType; }; // ------------------------------------------------------------ SomeObject::SomeObject(bool copy) : m_copy(copy) { } // ------------------------------------------------------------ void SomeObject::SetValue(const ComplexType &value) { if (m_copy) m_complexType.assign(value); else m_pComplexType = const_cast<ComplexType *>(&value); } The background behind this pattern is that it is used to hold data prior to it being encoded and sent to a TCP socket. The copy weirdness is designed to make the class SomeObject efficient by only holding a pointer to the object until it needs to be encoded, but also provide the option to copy values if the lifetime of the SomeObject exceeds the lifetime of a ComplexType. However, consider the following: SomeObject SomeFunction() { ComplexType complexTypeInstance(1); // Create an instance of ComplexType. SomeObject encodeHelper; encodeHelper.SetValue(complexTypeInstance); // Okay. return encodeHelper; // Uh oh! complexTypeInstance has been destroyed, and // now encoding will venture into the realm of undefined // behaviour! } I tripped over this because I used the default constructor, and this resulted in messages being encoded as blank (through a fluke of undefined behaviour). It took an absolute age to pinpoint the cause! Anyway, is this a standard pattern for something like this? Are there any advantages to doing it this way vs overloading the SetValue method to accept a pointer that I'm missing? Thanks!

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• Press alt + arrow to skip full line? (Or is there an existing shortcut already..? )

  - by Luka Kotar

  I am still a fresh Ubuntu user, and I switched from a Mac. What I can do on Mac, is I can press alt + arrow to jump one word forward or backward, or if I press cmd + arrow, I am able to jump to the start or end of the line. And that's what I would like to do in Ubuntu. I would assign it to the alt key, as ctrl is already used to skip words. I use that function a lot when coding, I like to keep my hands on the keyboard and just not touch the mouse at all, and it just saves me time for not having to hold the arrow key until I get to the end of the line (or the skip-a-word combo for that matter), or grabbing the mouse to click at the end, just to add a semicolon or something like that. It's not a huge deal, but that's just what I'm used to. I still keep my Mac partition for incompatibility issues, but I prefer Ubuntu over Mac. If there is already a shortcut to do that, I'd gladly go ahead and try getting comfortable using it, but if it is not, how could I achieve what I described above, if of course it is even possible? Thanks in advance, Luka.

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• How do audio based games such as Audiosurf and Beat Hazard work?

  - by The Communist Duck

  Note: I am not asking how to make a clone of one of these. I am asking about how they work. I'm sure everyone's seen the games where you use your own music files (or provided ones) and the games produce levels based on them, such as Audiosurf and Beat Hazard. Here is a video of Audiosurf in action, to show what I mean. If you provide a heavy metal song, you would get a completely different set of obstacles, enemies, and game experience from something like Vivaldi. What does interest me is how these games work. I do not know much about audio (well, data-side), but how do they process the song to understand when it is settling down or when it's speeding up? I guess they could just feed the pitch values (assuming those sorts of things exist in audio files) to form a level, but it wouldn't fully explain it. I'm either looking for an explanation, some links to articles about this sort of thing (I'm sure there's a term or terms for it), or even an open-source implementation of this kind of thing ;-) EDIT: After some searching and a little help, I found out about FFT (Fast Fourier Transform). This maybe a step in the right direction, but it is something that does not make any sense to me..or fits with my physics knowledge of waves.

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• How do I uninstall the TuxOnIce kernel in 12.04?

  - by Lluis

  I recently installed tuxonice on a Toshiba z830. I have ubuntu 12.04 (kernel was: 3.2.0-26) I wanted to be able to hibernate, which I consider to be a basic thing a OS should allow you to do. Well, it didn't work...but they already tell you it may not so I removed it. For doing all these I followed: Problem with Hibernation After uninstalling I switched off the laptop and after this I started to have several problems. The first one was that Cisco VPN didn't work anymore and then I realised that I could not even suspend my laptop. I found very strange that after removing tuxonice I still had this: /lib/modules/3.2.0-26-generic-tuxonice/ The VPN problem could be solved by just copying from my previous kernel: 3.2.0-26-generic/CiscoVPN/ into the tuxonice one. Not very elegant but works. Now, for the suspend problem (and the previous too) I can hold Shift when starting and select my old kernel and then suspend works again. In my opinion tuxonice was not correctly uninstalled as it left that kernel behind and worse: ubuntu uses it if I do not take action. I have these work arounds....and here is my question: how can I delete this tuxonice kernel safely? If you need more info please let me know.

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• I deleted all files and folders (including hidden) from /home/username/ now in big trouble

  - by jeffery_the_wind

  I am logged into a remote ubuntu server, and I accidentally erased the entire /home/username/ directory for the current user. The only thing left is a hidden directory called .gvfs. I don't need anything of the Documents/Music/etc. Now it is not letting me cd into the /var/www/ directory, which has permissions 666 and it is owned by the current user. I am afraid to disconnect from my ssh session because I don't know if I will be able to get back on. Have I permanently created a problem? Is there a way I can replace the most important files to the /home/username/ directory? Thanks! ** EDIT ** Thanks everyone for the help. I figured the problem with cd into the /var/www/ was actually my permissions in the /var/www/ directory. It was set to 666, changed it to 755 and everything was good again. It doesn't look like anything systematic was ruined by deleting the contents of the user folder.

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• Matching users based on a series of questions

  - by SeanWM

  I'm trying to figure out a way to match users based on specific personality traits. Each trait will have its own category. I figure in my user table I'll add a column for each category: id name cat1 cat2 cat3 1 Sean ? ? ? 2 Other ? ? ? Let's say I ask each user 3 questions in each category. For each question, you can answer one of the following: No, Maybe, Yes How would I calculate one number based off the answers in those 3 questions that would hold a value I can compare other users to? I was thinking having some sort of weight. Like: No -> 0 Maybe -> 1 Yes -> 2 Then doing some sort of meaningful calculation. I want to end up with something like this so I can query the users and find who matches close: id name cat1 cat2 cat3 1 Sean 4 5 1 2 Other 1 2 5 In the situation above, the users don't really match. I'd want to match with someone with a +1 or -1 of my score in each category. I'm not a math guy so I'm just looking for some ideas to get me started.

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• OOP Design: relationship between entity classes

  - by beginner_

  I have at first sight a simple issue but can't wrap my head around on how to solve. I have an abstract class Compound. A Compound is made up of Structures. Then there is also a Container which holds 1 Compound. A "special" implementation of Compound has Versions. For that type of Compound I want the Container to hold the Versionof the Compound and not the Compound itself. You could say "just create an interface Containable" and a Container holds 1 Containable. However that won't work. The reason is I'm creating a framework and the main part of that framework is to simplify storing and especially searching for special data type held by Structure objects. Hence to search for Containers which contain a Compound made up of a specific Structure requires that the "Path" from Containerto Structure is well defined (Number of relationships or joins). I hope this was understandable. My question is how to design the classes and relationships to be able to do what I outlined.

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• How to open-source a project whose git repository has copyrighted media in the history?

  - by phyzome

  I want to release an audio fingerprinting software project under a free license, but the repository contains copyrighted audio files. The test cases also currently use these files. How do I release the code to the public with maximum version history but without violating copyright? Details: The code is versioned under git. We will collapse it all back into one branch before release. There are 400 MB of audio data. Some files are free-licensed music from e.g. Jamendo, others are MP3s from our personal collections. No matter what approach we take, we'll always keep an immutable copy of the original repo, so as not to destroy project history. Main question: How to handle the public release? Expunge all history of the files in question from the git repository and release the altered repo. (v64 pointed out a way to do this.) Alternatively, take a snapshot of the current state of the code and don't even bother having a public history of the pre-release code. Side question: How could we have avoided this dilemma in the first place, given that sometimes private code or media is needed for the early stages of a project?

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• Hosting and scaling a Facebook application in the cloud? [closed]

  - by DhruvPathak

  Possible Duplicate: How to find web hosting that meets my requirements? We would be building a Facebook application in Django (Python), but still not sure of where to host it economically, and with a good provision to scale in case the app gets viral. Some details about the app: Would be HTML based like a website,using django as a framework. 100K is the number of expected pageviews in a day, if the app is viral. The users will not generate any media content, only some database data will be generated by them. It would be great if someone with more experience can guide on following points: A) Hosting on Google app engine or Amazon EC2 or some other cloud like RackSpace : Preferable points found in AppEngine were ease of deployment, cost effectiveness and easy scaling. For EC2: Full hold of the virtual machine,Amazon NoSQL and RDMBS database services in case we decide to use them. B) Does backend technology affect monthly cost? eg. would CPU and memory usage difference of Django over , for example , PHP framework like CodeIgnitor really make remarkable difference in running costs. (Here is the article that triggered this thought process : http://journal.dedasys.com/2010/01/12/rough-estimates-of-the-dollar-cost-of-scaling-web-platforms-part-i#comments) C) Does something like Heroku , which provides additional services over Amazon EC2, prove to be better than raw cloud management? It is not that we are trying for premature scaling, we just want to have a good start so that we are ready to handle unpredicted growth and scale.

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• Using mod_rewrite for a Virtual Filesystem vs. Real Filesystem

  - by philtune

  I started working in a department that uses a CMS in which the entire "filesystem" is like this: create a named file or folder - this file is given a unique node (ex. 2345) as well as a default "filename" (ex. /WelcomeToOurProductsPage) and apply a template assign one or more aliases to the file for a URL redirect (ex. /home-page-products - can also be accessed by /home-page-products.aspx) A new Rewrite command is written on the .htaccess file for each and every alias Server accesses either /WelcomeToOurProductsPage or /home-page-products and redirects to something like /template.aspx?tmp=2&node=2345 (here I'm guessing what it does - I only have front-end access for now - but I have enough clues to strongly assume) Node 2345 grabs content stored in a SQL Db and applies it to the template. Note: There are no actual files being created on the filesystem. It's entirely virtual. This is probably a very common thing, but since I have never run across this kind of system before two months ago, I wanted to explain it in case it isn't common. I'm not a fan at all of ASP or closed-sourced systems, so it may be that this is common practice for ASP developers. My question, that has taken far too long to ask, is: what are the benefits of this kind of system, as opposed to creating an actual file hierarchy? Are there any drawbacks to having every single file server call redirected? To having the .htaccess file hold rewrite rules for every single alias?

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• Ubuntu 12.10 and nVidia drivers don't like each other?

  - by mingos

  I decided to upgrade both my computers from Precise to Quantal. What a mistake that was. My laptop has a nVidia GT 330M card, while the desktop has an nVidia 9600 GT. In both cases everything goes great as long as I use the Nouveau driver (ugh!). Can't really play games (Amnesia... and hoping for Steam Beta participation...), even though it's OK for work. Now, ever since 9.04 or so, I just installed nvidia-current and all just worked. Since 12.10, after installing nVidia drivers, Unity won't start at all (hangs with only the wallpaper displayed, no cursor or widgets), Gnome Shell is permanently in fallback mode. Now, I have tried on both computers, with multiple clean installs on Ubuntu (two separate downloads, just in case), one from Ubuntu Gnome Remix. And additionally, Fedora 17, which seems to suffer from the same issue. Tried all nVidia driver suggestions available in Software Sources, and even compiled the drivers myself. I tried several versions of the driver to exclude an issue with the newest one. In my frustration, I have switched to Windows (which, ironically, "just works" with my hardware), but still hold a twin OS configuration on the desktop and would like to use Ubuntu again. So, can anyone point me to where the issue might lie?

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• How to prevent computer from automatically sleeping and/or hibernating?

  - by mehaase

  I'm running Ubuntu 12.04, and my laptop* won't wake from sleep/suspend/hibernate. (Is sleep the same thing as suspend?) I'm not even sure which of these things it's doing. When I am done working for the day, I lock my screen (Control-Alt-L). When I come back the next day, the screen is in power saving mode, and no amount of typing or clicking (on the usb keyboard/mouse or the builtin keyboard/trackpad) nor tapping the power button will bring it back to life. The only way I can get my machine to work is to hold down the power button until it shuts off, then press the power button again to turn it back on. Obviously, anything I had open from the previous day is pretty much gone -- in particular, my VMs all get rudely shut down without any warning. This is driving me INSANE. I spend the first hour of every work day trying to figure out how to get my computer to stop locking up over night. What I've tried: Editing the org.freedesktop.upower.policy to disable suspend and hibernate. Setting power management options in "Power" section of "System Settings". Looking at all power management options in the BIOS (none appear to be relevant to sleep/suspend/hibernate). Reading every forum post/askubuntu post that I can find that's even tangentially related to the subject. My question: how to disable the automatic sleep and/or hibernate (and/or anything similar) in Ubuntu 12.04. I don't care if it's still possible to sleep/suspend/hibernate/whatever by pushing buttons or running some command or reciting led zeppelin lyrics backwards. I just want my laptop to be ready for work in the morning. *The laptop is a Dell Latitude something or other. I don't want to get too specific because I've seen a lot of similar questions get closed for being too specific. I think my question is generic enough to stand -- it's a question about the latest, stable version of Ubuntu.

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• How to recover lost files after an install

  - by Gentry McColm

  I'm a newbie learning along the way. I recently installed a 2nd hdd into my ubuntu box. Have one of about 160g which runs ubuntu 12.04. And the new hdd was 1 tb, used for holding videos. I had set up 2nd drive as ext3 I believe. And set up folders on it to hold the videos. Worked great. Also thought I had set it up for auto mount. I was able to read and write on it. Etc. Computer froze, so had to reboot it. When I did, system would not reboot: hung on the Ubuntu screen with 5 dots. I hit a few buttons and the command screen showed up, indicating that my 2nd hdd would not mount. Stopped up whole system. Tried rebooting, no go. Had to reinstall ubuntu on the 1st hdd. Did not apparently touch the 2nd one. Well, when I got it up and running, my 2nd hdd mounted automatically (yeah!), but now I cannot find my videos I already had on it. I had not put any more than about 30g of videos on it, but now when I read its Properties, it says I'm using about 50g. So, I'm wondering if somewhere in that, buried, are my 17 videos. Any help in recovering this? Thanks!

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• How to Boot or "enter" into ubnutu 11.04 (Natty Narwhall) on PS3 after installing it?

  - by Xdm

  After failing to install ubuntu 11.04 Desktop version (burned on a dvd, because iso's file size was 726 Mb), in tried the alternate version (about 686 Mb) which i burned into a CD. During the installation process, i manually partitioned the hard drive using ext3. After the installation, the CD ejects itself and i hit "continue". In the k boot prompt i hit "enter" on my the keyboard. I see i welcome message in a dark background (a kind of full screen terminal/console called CLI i think) and was asked to enter my user name and password. After that, instead of booting into the beautiful desktop of Ubuntu, i saw this: ubuntu@my_name$ It was like a line of command i think, where you can use "sudo" commands. It is called a non-graphic mode i think. My my REAL problem is to enter Ubuntu 11.04 with the chocolate-colored background and the African music drum. I tried many commands to boot into the graphic mode of the system such as Ctr+Alt+F7 but nothing happened. In this case, i just saw numbers showing available blocks. I DON'T UNDERSTAND. I also tried startx and sudo startx without result. I DO bought a PS3 BOTH for gaming and for Ubuntu because i can't afford buying a PC. Please help me with my trouble dear Ubuntu 11.04 users. I am counting on you. All the best Xdm

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• The model to sell apps on App Store is better with a paid only version?

  - by ????

  Rob Napier, the author of iOS 5 Programming Pushing the Limits, mentioned there are several models of selling apps on the App Store: Write an app and sell it Publish a free and a full version Ad supported by third party or by iAd In App purchase Surprisingly, the author said that the most workable model is (1) in terms of sales. I would think that (2) with fairly limiting ability for the free version can bring more sales, as people without trying, might not plunge down $0.99 or $1.99 for something they haven't tried? I for one, might not have purchased Angry Birds if I didn't try their free version first. Also, I think it also depends on the situation: if the app is about alarm clock, and there are already 5 alarm clocks in App Store that are free, then your app that is $0.99 might not be that eagerly purchased. If yours is also free, and users really like it out of all the other ones, then they may think, $0.99 is nothing to get a good alarm clock, and gladly pay you the $0.99 in exchange for a full version of the alarm clock, something that they can't get with the free version. (such as the full version can let you choose a song from your Music Library for the alarm). Could (1) work only if the user definitely want it and have no substitute? How might it work the best?

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• How do I install Kodos in 12.10?

  - by Brutus

  In previous Ubuntu version I used Kodos extensively. But the package has been dropped in 12.10. It's a neat regular expression testing tool. It's hard to find an alternative that is not Windows only (or Air, or uses action script which bails on more complicated RegEx, or works in Wine - well kinda, but not really..., etc.). So I tried to install Kodos from source, which seems to work (download sourceball and setup.py) but it won't run because of missing PyQT dependencies (that I can't manage to fulfill with anything install-able trough standard packages). I then tried to install PyQT manually (which seems to require manual install of SIP and QT too) and instead of pip I have to use configure.py and qmake. It throws error after error at me. I tried to overcome one after another for over an hour but no luck. It even managed to break Calibre and Music Brains Picard. So I purged all the stuff, reinstalled python-sipand python-qt4 from the standard packages and gave up. Has anyone managed to get Kodos running on 12.10? Or any hints on how to do it?

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• Data structure for grid with negative indeces

  - by The Secret Imbecile

  Sorry if this is an insultingly obvious concept, but it's something I haven't done before and I've been unable to find any material discussing the best way to approach it. I'm wondering what's the best data structure for holding a 2D grid of unknown size. The grid has integer coordinates (x,y), and will have negative indices in both directions. So, what is the best way to hold this grid? I'm programming in c# currently, so I can't have negative array indices. My initial thought was to have class with 4 separate arrays for (+x,+y),(+x,-y),(-x,+y), and (-x,-y). This seems to be a valid way to implement the grid, but it does seem like I'm over-engineering the solution, and array resizing will be a headache. Another idea was to keep track of the center-point of the array and set that as the topological (0,0), however I would have the issue of having to do a shift to every element of the grid when repeatedly adding to the top-left of the grid, which would be similar to grid resizing though in all likelihood more frequent. Thoughts?

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• How do you quantify competency in terms of time (years)?

  - by o.k.w

  While looking for a job via agencies some time ago, I kept having questions from the recuitment agents or in the application forms like: How many years of experience do you have in: Oracle ASP.NET J2EE etc etc etc.... At first I answered faithfully... 5yrs, 7yrs, 2 yrs, none, few months etc etc.. Then I thought; I can be doing something shallow for 7 years and not being competent at it simply because I am just doing a minor support for a legacy system running SQL2000 which requires 10 days of my time for the past 7 years. Eventualy I declined to answers such questions. I wonder why do they ask these questions anymore. Anyone who just graduated with a computer science can claim 3 to 4 years experience in anything they 'touched' in the cirriculum, which to me can be equivalent to zero or 10 years depending how you look at it. It might hold true decades ago where programmers and IT skills are of very different nature. I might be wrong but I really doubt 'time' or 'years' are a good gauge of competency or experience anymore. Any opinion/rebuttal are welcome!

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• Unable to debug javascript?

  - by linkme69

  I’m having some problems debugging an encoded javacscript. This script I’m referring to given in this link over here. The encoding here is simple and it works by shifting the unicodes values to whatever Codekey was use during encoding. The code that does the decoding is given here in plain English below:- <script language="javascript"> function dF(s){ var s1=unescape(s.substr(0,s.length-1)); var t=''; for(i=0;i<s1.length;i++)t+=String.fromCharCode(s1.charCodeAt(i)-s.substr(s.length-1,1)); document.write(unescape(t)); } I’m interested in knowing or understanding the values (e.g s1,t). Like for example when the value of i=0 what values would the following attributes / method would hold s1.charCodeAt(i) and s.substr(s.length-1,1) The reason I’m doing this is to understand as to how a CodeKey function really works. I don’t see anything in the code above which tells it to decode on the basis of codekey value. The only thing I can point in the encoding text is the last character which is set to 1 , 2 ,3 or 4 depending upon the codekey selected during encoding process. One can verify using the link I have given above. However, to debug, I’m using firebug addon with the script running as localhost on my wamp server. I’m able to put a breakpoint on the js using firebug but I’m unable to retrieve any of the user defined parameters or functions I mentioned above. I want to know under this context what would be best way to debug this encoded js.

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• How do I have an arrow follow different height parabolas depending on how long the player holds down a key?

  - by Moondustt

  i'm trying to throw an arrow in my game, but i'm having a hard time trying to realize how to make a good parabola. What I need: The more you hold "enter" stronger the arrow goes. The arrow angle will be always the same, 45 degrees. This is what I have already have: private float velocityHeld = 1f; protected override void Update(GameTime gameTime) { private void GetKeyboardEvent() { if (Keyboard.GetState().IsKeyDown(Keys.Enter) && !released) { timeHeld += velocityHeld; holding = true; } else { if (holding) { released = true; holding = false; lastTimeHeld = timeHeld; } } } if (released && timeHeld > 0) { float alpha = MathHelper.ToRadians(45f); double vy = timeHeld * Math.Sin(alpha); double vx = timeHeld * Math.Cos(alpha); ShadowPosition.Y -= (int)vy; ShadowPosition.X += (int)vx; timeHeld -= velocityHeld; } else { released = false; } } My question is, what do I need to do to make the arrow to go bottom as it loses velocity (timeHeld) to make a perfect parabola?

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• Android app crashes on emulator - logCat shows no errors

  - by David Miler

  I have just added the SherlockActionBar library to my android project. After some small changes (FragmentActivity - SherlockFragmentActivity, getActionBar() - getSupportActionBar(), imports) it all compiled nicely. After I run the app, however, the debugger stops, as though it had encountered an exception. However, there are no errors shown in the LogCat output. I just can't wrap my head around what's going on. Here is the logCat output after I terminate the app. 10-02 14:11:19.227: I/SystemUpdateService(174): UpdateTask at time 1349187079227 10-02 14:11:19.237: I/ActivityThread(328): Pub com.android.email.attachmentprovider: com.android.email.provider.AttachmentProvider 10-02 14:11:19.687: I/dalvikvm(81): Jit: resizing JitTable from 512 to 1024 10-02 14:11:19.809: D/MediaScannerService(150): start scanning volume internal: [/system/media] 10-02 14:11:20.047: V/AlarmClock(239): AlarmInitReceiver finished 10-02 14:11:20.087: I/ActivityManager(81): Start proc com.android.quicksearchbox for broadcast com.android.quicksearchbox/.SearchWidgetProvider: pid=346 uid=10012 gids={3003} 10-02 14:11:20.127: D/ExchangeService(320): !!! EAS ExchangeService, onStartCommand, startingUp = false, running = false 10-02 14:11:20.427: I/ActivityThread(346): Pub com.android.quicksearchbox.google: com.android.quicksearchbox.google.GoogleSuggestionProvider 10-02 14:11:20.497: I/ActivityThread(346): Pub com.android.quicksearchbox.shortcuts: com.android.quicksearchbox.ShortcutsProvider 10-02 14:11:20.657: I/ActivityManager(81): Start proc com.android.music for broadcast com.android.music/.MediaAppWidgetProvider: pid=358 uid=10028 gids={3003, 1015} 10-02 14:11:20.927: D/ExchangeService(320): !!! EAS ExchangeService, onCreate 10-02 14:11:20.967: D/dalvikvm(260): GC_CONCURRENT freed 213K, 6% free 6409K/6791K, paused 5ms+101ms 10-02 14:11:21.077: D/ExchangeService(320): !!! EAS ExchangeService, onStartCommand, startingUp = true, running = false 10-02 14:11:21.567: D/GTalkService(174): [ReonnectMgr] ### report Inet condition: status=false, networkType=0 10-02 14:11:21.587: D/ConnectivityService(81): reportNetworkCondition(0, 0) 10-02 14:11:21.597: D/ConnectivityService(81): Inet connectivity change, net=0, condition=0,mActiveDefaultNetwork=0 10-02 14:11:21.597: D/ConnectivityService(81): starting a change hold 10-02 14:11:21.697: D/GTalkService(174): [RawStanzaProvidersMgr] ##### searchProvidersFromIntent 10-02 14:11:21.697: D/GTalkService(174): [RawStanzaProvidersMgr] no intent receivers found 10-02 14:11:21.847: I/SystemUpdateService(174): cancelUpdate (empty URL) 10-02 14:11:21.847: E/TelephonyManager(174): Hidden constructor called more than once per process! 10-02 14:11:21.867: D/dalvikvm(174): GC_CONCURRENT freed 337K, 7% free 6561K/7047K, paused 5ms+4ms 10-02 14:11:21.917: D/GTalkService(174): [ReonnectMgr] ### report Inet condition: status=false, networkType=0 10-02 14:11:21.917: D/ConnectivityService(81): reportNetworkCondition(0, 0) 10-02 14:11:21.917: D/ConnectivityService(81): Inet connectivity change, net=0, condition=0,mActiveDefaultNetwork=0 10-02 14:11:21.917: D/ConnectivityService(81): currently in hold - not setting new end evt 10-02 14:11:21.990: E/TelephonyManager(174): Original: com.google.android.location, new: com.google.android.gsf 10-02 14:11:22.027: I/SystemUpdateService(174): removeAllDownloads (cancelUpdate) 10-02 14:11:22.127: D/dalvikvm(328): GC_CONCURRENT freed 205K, 6% free 6506K/6855K, paused 660ms+3ms 10-02 14:11:22.197: D/Eas Debug(320): Logging: 10-02 14:11:22.319: D/dalvikvm(81): GREF has increased to 401 10-02 14:11:22.947: D/ExchangeService(320): !!! EAS ExchangeService, onStartCommand, startingUp = true, running = false 10-02 14:11:23.130: D/Eas Debug(320): Logging: 10-02 14:11:23.307: I//system/bin/fsck_msdos(29): Attempting to allocate 2044 KB for FAT 10-02 14:11:23.560: I/ActivityManager(81): Starting: Intent { flg=0x10000000 cmp=com.google.android.gsf/.update.SystemUpdateInstallDialog } from pid 174 10-02 14:11:23.587: I/ActivityManager(81): Starting: Intent { flg=0x10000000 cmp=com.google.android.gsf/.update.SystemUpdateDownloadDialog } from pid 174 10-02 14:11:24.087: W/ActivityManager(81): Activity pause timeout for ActivityRecord{407c7320 com.android.launcher/com.android.launcher2.Launcher} 10-02 14:11:24.237: E/TelephonyManager(174): Hidden constructor called more than once per process! 10-02 14:11:24.237: E/TelephonyManager(174): Original: com.google.android.location, new: com.google.android.gsf 10-02 14:11:24.507: D/dalvikvm(174): GC_EXPLICIT freed 231K, 7% free 6596K/7047K, paused 4ms+6ms 10-02 14:11:24.607: D/ConnectivityService(81): Inet hold end, net=0, condition =0, published condition =0 10-02 14:11:24.607: D/ConnectivityService(81): no change in condition - aborting 10-02 14:11:24.707: D/dalvikvm(174): GC_EXPLICIT freed 17K, 7% free 6579K/7047K, paused 4ms+4ms 10-02 14:11:24.947: I//system/bin/fsck_msdos(29): ** Phase 2 - Check Cluster Chains 10-02 14:11:25.117: I//system/bin/fsck_msdos(29): ** Phase 3 - Checking Directories 10-02 14:11:25.128: I//system/bin/fsck_msdos(29): ** Phase 4 - Checking for Lost Files 10-02 14:11:25.167: I//system/bin/fsck_msdos(29): 12 files, 1044448 free (522224 clusters) 10-02 14:11:25.227: I/Vold(29): Filesystem check completed OK 10-02 14:11:25.227: I/Vold(29): Device /dev/block/vold/179:0, target /mnt/sdcard mounted @ /mnt/secure/staging 10-02 14:11:25.237: D/Vold(29): Volume sdcard state changing 3 (Checking) -> 4 (Mounted) 10-02 14:11:25.257: I/PackageManager(81): Updating external media status from unmounted to mounted 10-02 14:11:25.457: D/dalvikvm(303): GC_EXPLICIT freed 35K, 6% free 6242K/6595K, paused 3ms+312ms 10-02 14:11:25.987: D/ExchangeService(320): !!! EAS ExchangeService, onStartCommand, startingUp = true, running = false 10-02 14:11:26.157: D/MediaScanner(150): prescan time: 2905ms 10-02 14:11:26.167: D/MediaScanner(150): scan time: 148ms 10-02 14:11:26.167: D/MediaScanner(150): postscan time: 2ms 10-02 14:11:26.167: D/MediaScanner(150): total time: 3055ms 10-02 14:11:26.197: D/MediaScannerService(150): done scanning volume internal 10-02 14:11:26.237: D/MediaScannerService(150): start scanning volume external: [/mnt/sdcard] 10-02 14:11:26.497: D/dalvikvm(143): GC_EXPLICIT freed 234K, 8% free 7735K/8327K, paused 3ms+5ms 10-02 14:11:27.180: D/dalvikvm(143): GC_CONCURRENT freed 150K, 4% free 8004K/8327K, paused 7ms+3ms 10-02 14:11:27.397: D/dalvikvm(143): GC_FOR_ALLOC freed 96K, 6% free 8310K/8775K, paused 76ms 10-02 14:11:27.580: D/dalvikvm(143): GC_FOR_ALLOC freed 515K, 11% free 8135K/9095K, paused 79ms 10-02 14:11:27.829: D/dalvikvm(143): GC_CONCURRENT freed 3K, 5% free 8694K/9095K, paused 7ms+6ms 10-02 14:11:28.137: V/TLINE(143): new: android.text.TextLine@4065b280 10-02 14:11:28.527: D/dalvikvm(143): GC_CONCURRENT freed 729K, 10% free 8764K/9671K, paused 5ms+13ms 10-02 14:11:28.677: D/dalvikvm(143): GC_FOR_ALLOC freed 152K, 11% free 8683K/9671K, paused 99ms 10-02 14:11:28.717: I/dalvikvm-heap(143): Grow heap (frag case) to 11.434MB for 2975968-byte allocation 10-02 14:11:28.807: D/dalvikvm(143): GC_FOR_ALLOC freed 0K, 9% free 11589K/12615K, paused 84ms 10-02 14:11:29.159: D/dalvikvm(143): GC_CONCURRENT freed 197K, 7% free 12195K/12999K, paused 8ms+6ms 10-02 14:11:29.647: D/dalvikvm(143): GC_EXPLICIT freed 351K, 6% free 12790K/13511K, paused 8ms+17ms 10-02 14:11:29.717: I/SurfaceFlinger(32): Boot is finished (70768 ms) 10-02 14:11:29.877: I/ARMAssembler(32): generated scanline__00000177:03010104_00000002_00000000 [ 44 ipp] (66 ins) at [0x407c7290:0x407c7398] in 990662 ns 10-02 14:11:29.907: I/ARMAssembler(32): generated scanline__00000177:03515104_00000001_00000000 [ 73 ipp] (95 ins) at [0x407c73a0:0x407c751c] in 989381 ns 10-02 14:11:30.287: D/dalvikvm(174): GC_EXPLICIT freed 25K, 8% free 6554K/7047K, paused 4ms+32ms 10-02 14:11:30.380: D/dalvikvm(143): GC_EXPLICIT freed 349K, 6% free 13124K/13895K, paused 5ms+25ms 10-02 14:11:30.957: D/dalvikvm(143): GC_FOR_ALLOC freed 1069K, 10% free 13860K/15239K, paused 81ms 10-02 14:11:32.177: D/dalvikvm(150): GC_CONCURRENT freed 183K, 6% free 6438K/6791K, paused 5ms+4ms 10-02 14:11:32.187: W/ActivityManager(81): No content provider found for: 10-02 14:11:32.607: V/MediaScanner(150): pruneDeadThumbnailFiles... android.database.sqlite.SQLiteCursor@406724a8 10-02 14:11:32.617: V/MediaScanner(150): /pruneDeadThumbnailFiles... android.database.sqlite.SQLiteCursor@406724a8 10-02 14:11:32.640: W/ActivityManager(81): No content provider found for: 10-02 14:11:32.640: D/VoldCmdListener(29): asec list 10-02 14:11:32.647: I/PackageManager(81): No secure containers on sdcard 10-02 14:11:32.667: D/MediaScanner(150): prescan time: 107ms 10-02 14:11:32.667: D/MediaScanner(150): scan time: 89ms 10-02 14:11:32.667: D/MediaScanner(150): postscan time: 61ms 10-02 14:11:32.667: D/MediaScanner(150): total time: 257ms 10-02 14:11:32.697: W/PackageManager(81): Unknown permission android.permission.ADD_SYSTEM_SERVICE in package com.android.phone 10-02 14:11:32.707: W/PackageManager(81): Unknown permission com.android.smspush.WAPPUSH_MANAGER_BIND in package com.android.phone 10-02 14:11:32.737: W/PackageManager(81): Not granting permission android.permission.SEND_DOWNLOAD_COMPLETED_INTENTS to package com.android.browser (protectionLevel=2 flags=0x9be45) 10-02 14:11:32.737: W/PackageManager(81): Not granting permission android.permission.BIND_APPWIDGET to package com.android.widgetpreview (protectionLevel=3 flags=0x28be44) 10-02 14:11:32.767: W/PackageManager(81): Unknown permission android.permission.READ_OWNER_DATA in package com.android.exchange 10-02 14:11:32.778: W/PackageManager(81): Unknown permission android.permission.READ_OWNER_DATA in package com.android.email 10-02 14:11:32.788: W/PackageManager(81): Unknown permission com.android.providers.im.permission.READ_ONLY in package com.google.android.apps.maps 10-02 14:11:32.797: W/PackageManager(81): Not granting permission android.permission.DEVICE_POWER to package com.android.deskclock (protectionLevel=2 flags=0x8be45) 10-02 14:11:33.137: D/MediaScannerService(150): done scanning volume external 10-02 14:11:33.197: D/PackageParser(81): Scanning package: /data/app/vmdl257911298.tmp 10-02 14:11:33.837: I/InputReader(81): Device reconfigured: id=0, name='qwerty2', surface size is now 1024x800 10-02 14:11:34.097: D/dalvikvm(81): GC_CONCURRENT freed 12185K, 47% free 13966K/26311K, paused 8ms+23ms 10-02 14:11:36.798: I/TabletStatusBar(124): DISABLE_CLOCK: no 10-02 14:11:36.798: I/TabletStatusBar(124): DISABLE_NAVIGATION: no 10-02 14:11:37.348: I/ARMAssembler(32): generated scanline__00000177:03515104_00001001_00000000 [ 91 ipp] (114 ins) at [0x407c7520:0x407c76e8] in 919320 ns 10-02 14:11:37.598: I/TabletStatusBar(124): DISABLE_BACK: no 10-02 14:11:37.710: I/ActivityManager(81): Displayed com.android.launcher/com.android.launcher2.Launcher: +46s212ms 10-02 14:11:38.817: D/dalvikvm(143): GC_CONCURRENT freed 969K, 8% free 14867K/16007K, paused 4ms+10ms 10-02 14:11:39.437: I/dalvikvm(81): Jit: resizing JitTable from 1024 to 2048 10-02 14:11:40.267: D/dalvikvm(143): GC_FOR_ALLOC freed 2357K, 16% free 14395K/17031K, paused 80ms 10-02 14:11:40.717: D/dalvikvm(143): GC_EXPLICIT freed 742K, 16% free 14358K/17031K, paused 8ms+4ms 10-02 14:11:41.617: D/dalvikvm(81): GC_CONCURRENT freed 1955K, 48% free 13869K/26311K, paused 9ms+10ms 10-02 14:11:42.559: D/dalvikvm(81): GC_CONCURRENT freed 1830K, 48% free 13881K/26311K, paused 9ms+9ms 10-02 14:11:42.758: I/PackageManager(81): Removing non-system package:cz.trilimi.sfaui 10-02 14:11:42.758: I/ActivityManager(81): Force stopping package cz.trilimi.sfaui uid=10036 10-02 14:11:42.967: D/PackageManager(81): Scanning package cz.trilimi.sfaui 10-02 14:11:42.967: I/PackageManager(81): Package cz.trilimi.sfaui codePath changed from /data/app/cz.trilimi.sfaui-1.apk to /data/app/cz.trilimi.sfaui-2.apk; Retaining data and using new 10-02 14:11:42.967: I/PackageManager(81): Unpacking native libraries for /data/app/cz.trilimi.sfaui-2.apk 10-02 14:11:43.097: D/installd(35): DexInv: --- BEGIN '/data/app/cz.trilimi.sfaui-2.apk' --- 10-02 14:11:45.317: D/dalvikvm(391): DexOpt: load 434ms, verify+opt 1260ms 10-02 14:11:45.407: D/installd(35): DexInv: --- END '/data/app/cz.trilimi.sfaui-2.apk' (success) --- 10-02 14:11:45.407: W/PackageManager(81): Code path for pkg : cz.trilimi.sfaui changing from /data/app/cz.trilimi.sfaui-1.apk to /data/app/cz.trilimi.sfaui-2.apk 10-02 14:11:45.407: W/PackageManager(81): Resource path for pkg : cz.trilimi.sfaui changing from /data/app/cz.trilimi.sfaui-1.apk to /data/app/cz.trilimi.sfaui-2.apk 10-02 14:11:45.407: D/PackageManager(81): Activities: cz.trilimi.sfaui.ItemListActivity cz.trilimi.sfaui.ItemDetailActivity 10-02 14:11:45.427: I/ActivityManager(81): Force stopping package cz.trilimi.sfaui uid=10036 10-02 14:11:45.657: I/installd(35): move /data/dalvik-cache/data@[email protected]@classes.dex -> /data/dalvik-cache/data@[email protected]@classes.dex 10-02 14:11:45.657: D/PackageManager(81): New package installed in /data/app/cz.trilimi.sfaui-2.apk 10-02 14:11:45.997: I/ActivityManager(81): Force stopping package cz.trilimi.sfaui uid=10036 10-02 14:11:46.147: D/dalvikvm(143): GC_EXPLICIT freed 3K, 16% free 14356K/17031K, paused 10ms+9ms 10-02 14:11:46.237: D/PackageManager(81): generateServicesMap(android.accounts.AccountAuthenticator): 3 services unchanged 10-02 14:11:46.277: D/PackageManager(81): generateServicesMap(android.content.SyncAdapter): 5 services unchanged 10-02 14:11:46.337: D/PackageManager(81): generateServicesMap(android.accounts.AccountAuthenticator): 3 services unchanged 10-02 14:11:46.347: D/PackageManager(81): generateServicesMap(android.content.SyncAdapter): 5 services unchanged 10-02 14:11:46.437: D/dalvikvm(208): GC_EXPLICIT freed 258K, 7% free 6488K/6919K, paused 3ms+5ms 10-02 14:11:46.477: W/RecognitionManagerService(81): no available voice recognition services found 10-02 14:11:46.897: I/ActivityManager(81): Start proc com.svox.pico for broadcast com.svox.pico/.VoiceDataInstallerReceiver: pid=398 uid=10006 gids={} 10-02 14:11:47.087: I/ActivityThread(398): Pub com.svox.pico.providers.SettingsProvider: com.svox.pico.providers.SettingsProvider 10-02 14:11:47.138: D/GTalkService(174): [GTalkService.1] handlePackageInstalled: re-initialize providers 10-02 14:11:47.147: D/GTalkService(174): [RawStanzaProvidersMgr] ##### searchProvidersFromIntent 10-02 14:11:47.147: D/GTalkService(174): [RawStanzaProvidersMgr] no intent receivers found 10-02 14:11:47.718: I/AccountTypeManager(208): Loaded meta-data for 1 account types, 0 accounts in 186ms 10-02 14:11:48.377: D/dalvikvm(143): GC_CONCURRENT freed 1865K, 15% free 14513K/17031K, paused 7ms+4ms 10-02 14:11:48.917: D/dalvikvm(208): GC_CONCURRENT freed 219K, 6% free 6788K/7175K, paused 7ms+73ms 10-02 14:11:49.207: D/dalvikvm(143): GC_FOR_ALLOC freed 4558K, 31% free 11866K/17031K, paused 89ms 10-02 14:11:49.587: D/dalvikvm(143): GC_CONCURRENT freed 713K, 24% free 13010K/17031K, paused 5ms+4ms 10-02 14:11:49.967: D/dalvikvm(143): GC_CONCURRENT freed 1046K, 19% free 13922K/17031K, paused 5ms+4ms 10-02 14:11:50.437: D/dalvikvm(81): GC_EXPLICIT freed 898K, 47% free 13955K/26311K, paused 6ms+39ms 10-02 14:11:50.467: I/installd(35): unlink /data/dalvik-cache/data@[email protected]@classes.dex 10-02 14:11:50.477: D/AndroidRuntime(227): Shutting down VM 10-02 14:11:50.507: D/dalvikvm(227): GC_CONCURRENT freed 97K, 84% free 331K/2048K, paused 1ms+2ms 10-02 14:11:50.507: I/AndroidRuntime(227): NOTE: attach of thread 'Binder Thread #3' failed 10-02 14:11:50.517: D/jdwp(227): adbd disconnected 10-02 14:11:51.177: D/AndroidRuntime(410): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<< 10-02 14:11:51.177: D/AndroidRuntime(410): CheckJNI is ON 10-02 14:11:51.897: D/AndroidRuntime(410): Calling main entry com.android.commands.am.Am 10-02 14:11:51.937: I/ActivityManager(81): Force stopping package cz.trilimi.sfaui uid=10036 10-02 14:11:51.937: I/ActivityManager(81): Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=cz.trilimi.sfaui/.ItemListActivity } from pid 410 10-02 14:11:51.968: W/WindowManager(81): Failure taking screenshot for (230x179) to layer 21005 10-02 14:11:51.997: I/ActivityManager(81): Start proc cz.trilimi.sfaui for activity cz.trilimi.sfaui/.ItemListActivity: pid=418 uid=10036 gids={} 10-02 14:11:52.007: D/AndroidRuntime(410): Shutting down VM 10-02 14:11:52.057: I/AndroidRuntime(410): NOTE: attach of thread 'Binder Thread #3' failed 10-02 14:11:52.097: D/dalvikvm(410): GC_CONCURRENT freed 98K, 83% free 360K/2048K, paused 1ms+0ms 10-02 14:11:52.097: D/jdwp(410): adbd disconnected 10-02 14:11:53.147: W/ActivityThread(418): Application cz.trilimi.sfaui is waiting for the debugger on port 8100... 10-02 14:11:53.207: I/System.out(418): Sending WAIT chunk 10-02 14:11:53.217: I/dalvikvm(418): Debugger is active 10-02 14:11:53.447: I/System.out(418): Debugger has connected 10-02 14:11:53.457: I/System.out(418): waiting for debugger to settle... 10-02 14:11:53.637: I/ARMAssembler(32): generated scanline__00000177:03515104_00001002_00000000 [ 87 ipp] (110 ins) at [0x407c76f0:0x407c78a8] in 598498 ns 10-02 14:11:53.660: I/System.out(418): waiting for debugger to settle... 10-02 14:11:53.857: I/System.out(418): waiting for debugger to settle... 10-02 14:11:54.057: I/System.out(418): waiting for debugger to settle... 10-02 14:11:54.257: I/System.out(418): waiting for debugger to settle... 10-02 14:11:54.317: V/TLINE(81): new: android.text.TextLine@4155dde8 10-02 14:11:54.467: I/System.out(418): waiting for debugger to settle... 10-02 14:11:54.667: I/System.out(418): waiting for debugger to settle... 10-02 14:11:54.870: I/System.out(418): waiting for debugger to settle... 10-02 14:11:55.027: D/dalvikvm(143): GC_EXPLICIT freed 900K, 16% free 14420K/17031K, paused 7ms+4ms 10-02 14:11:55.067: I/System.out(418): waiting for debugger to settle... 10-02 14:11:55.292: I/System.out(418): debugger has settled (1315) 10-02 14:12:02.008: W/ActivityManager(81): Launch timeout has expired, giving up wake lock! 10-02 14:12:02.971: W/ActivityManager(81): Activity idle timeout for ActivityRecord{4078c6b0 cz.trilimi.sfaui/.ItemListActivity} 10-02 14:12:08.359: D/ExchangeService(320): Received deviceId from Email app: androidc259148960 10-02 14:12:08.507: D/ExchangeService(320): Reconciling accounts... 10-02 14:16:11.437: D/SntpClient(81): request time failed: java.net.SocketException: Address family not supported by protocol 10-02 14:17:21.573: W/jdwp(418): Debugger is telling the VM to exit with code=1 10-02 14:17:21.573: I/dalvikvm(418): GC lifetime allocation: 8642 bytes 10-02 14:17:21.637: D/Zygote(33): Process 418 exited cleanly (1) 10-02 14:17:21.651: I/ActivityManager(81): Process cz.trilimi.sfaui (pid 418) has died. 10-02 14:17:21.847: D/dalvikvm(143): GC_EXPLICIT freed <1K, 16% free 14420K/17031K, paused 7ms+7ms 10-02 14:17:21.917: W/InputManagerService(81): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@40bfbf28

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• How to remove a package entirely?

  - by maria

  Hi I'm quite new to Linux, but before using it I was hearing that Windows programs, after uninstallation, leaves a lot of remains on the hard disc, and Linux removes all. I'm using Ubuntu 10.04. To uninstall packages I'm using sudo apt-get autoremove application_name or sudo aptitude purge application_name. Recently I have installed texlive-full and for some reasons I had quickly to uninstall it. After I've entered to terminal updatedb, then locate *texlive* and the output was very long: maria@marysia-ubuntu:~$ locate *texlive* /etc/texmf/fmt.d/10texlive-base.cnf /etc/texmf/fmt.d/10texlive-formats-extra.cnf /etc/texmf/fmt.d/10texlive-lang-cyrillic.cnf /etc/texmf/fmt.d/10texlive-lang-czechslovak.cnf /etc/texmf/fmt.d/10texlive-lang-polish.cnf /etc/texmf/fmt.d/10texlive-latex-base.cnf /etc/texmf/fmt.d/10texlive-math-extra.cnf /etc/texmf/fmt.d/10texlive-metapost.cnf /etc/texmf/fmt.d/10texlive-omega.cnf /etc/texmf/fmt.d/10texlive-xetex.cnf /etc/texmf/hyphen.d/09texlive-base.cnf /etc/texmf/hyphen.d/10texlive-lang-arabic.cnf /etc/texmf/hyphen.d/10texlive-lang-croatian.cnf /etc/texmf/hyphen.d/10texlive-lang-cyrillic.cnf /etc/texmf/hyphen.d/10texlive-lang-czechslovak.cnf /etc/texmf/hyphen.d/10texlive-lang-danish.cnf /etc/texmf/hyphen.d/10texlive-lang-dutch.cnf /etc/texmf/hyphen.d/10texlive-lang-finnish.cnf /etc/texmf/hyphen.d/10texlive-lang-french.cnf /etc/texmf/hyphen.d/10texlive-lang-german.cnf /etc/texmf/hyphen.d/10texlive-lang-greek.cnf /etc/texmf/hyphen.d/10texlive-lang-hungarian.cnf /etc/texmf/hyphen.d/10texlive-lang-indic.cnf /etc/texmf/hyphen.d/10texlive-lang-italian.cnf /etc/texmf/hyphen.d/10texlive-lang-latin.cnf /etc/texmf/hyphen.d/10texlive-lang-latvian.cnf /etc/texmf/hyphen.d/10texlive-lang-lithuanian.cnf /etc/texmf/hyphen.d/10texlive-lang-mongolian.cnf /etc/texmf/hyphen.d/10texlive-lang-norwegian.cnf /etc/texmf/hyphen.d/10texlive-lang-other.cnf /etc/texmf/hyphen.d/10texlive-lang-polish.cnf /etc/texmf/hyphen.d/10texlive-lang-portuguese.cnf /etc/texmf/hyphen.d/10texlive-lang-spanish.cnf /etc/texmf/hyphen.d/10texlive-lang-swedish.cnf /etc/texmf/hyphen.d/10texlive-lang-ukenglish.cnf /etc/texmf/updmap.d/10texlive-base.cfg /etc/texmf/updmap.d/10texlive-fonts-extra.cfg /etc/texmf/updmap.d/10texlive-fonts-recommended.cfg /etc/texmf/updmap.d/10texlive-games.cfg /etc/texmf/updmap.d/10texlive-lang-african.cfg /etc/texmf/updmap.d/10texlive-lang-arabic.cfg /etc/texmf/updmap.d/10texlive-lang-cyrillic.cfg /etc/texmf/updmap.d/10texlive-lang-czechslovak.cfg /etc/texmf/updmap.d/10texlive-lang-french.cfg /etc/texmf/updmap.d/10texlive-lang-greek.cfg /etc/texmf/updmap.d/10texlive-lang-hebrew.cfg /etc/texmf/updmap.d/10texlive-lang-indic.cfg /etc/texmf/updmap.d/10texlive-lang-lithuanian.cfg /etc/texmf/updmap.d/10texlive-lang-mongolian.cfg /etc/texmf/updmap.d/10texlive-lang-polish.cfg /etc/texmf/updmap.d/10texlive-lang-vietnamese.cfg /etc/texmf/updmap.d/10texlive-latex-base.cfg /etc/texmf/updmap.d/10texlive-latex-extra.cfg /etc/texmf/updmap.d/10texlive-math-extra.cfg /etc/texmf/updmap.d/10texlive-omega.cfg /etc/texmf/updmap.d/10texlive-pictures.cfg /etc/texmf/updmap.d/10texlive-science.cfg /var/cache/apt/archives/texlive-base_2009-7_all.deb /var/cache/apt/archives/texlive-bibtex-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-binaries_2009-5ubuntu0.2_i386.deb /var/cache/apt/archives/texlive-common_2009-7_all.deb /var/cache/apt/archives/texlive-doc-base_2009-2_all.deb /var/cache/apt/archives/texlive-doc-bg_2009-2_all.deb /var/cache/apt/archives/texlive-doc-cs+sk_2009-2_all.deb /var/cache/apt/archives/texlive-doc-de_2009-2_all.deb /var/cache/apt/archives/texlive-doc-en_2009-2_all.deb /var/cache/apt/archives/texlive-doc-es_2009-2_all.deb /var/cache/apt/archives/texlive-doc-fi_2009-2_all.deb /var/cache/apt/archives/texlive-doc-fr_2009-2_all.deb /var/cache/apt/archives/texlive-doc-it_2009-2_all.deb /var/cache/apt/archives/texlive-doc-ja_2009-2_all.deb /var/cache/apt/archives/texlive-doc-ko_2009-2_all.deb /var/cache/apt/archives/texlive-doc-mn_2009-2_all.deb /var/cache/apt/archives/texlive-doc-nl_2009-2_all.deb /var/cache/apt/archives/texlive-doc-pl_2009-2_all.deb /var/cache/apt/archives/texlive-doc-pt_2009-2_all.deb /var/cache/apt/archives/texlive-doc-ru_2009-2_all.deb /var/cache/apt/archives/texlive-doc-si_2009-2_all.deb /var/cache/apt/archives/texlive-doc-th_2009-2_all.deb /var/cache/apt/archives/texlive-doc-tr_2009-2_all.deb /var/cache/apt/archives/texlive-doc-uk_2009-2_all.deb /var/cache/apt/archives/texlive-doc-vi_2009-2_all.deb /var/cache/apt/archives/texlive-doc-zh_2009-2_all.deb /var/cache/apt/archives/texlive-extra-utils_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-font-utils_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-fonts-extra-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-fonts-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-fonts-recommended-doc_2009-7_all.deb /var/cache/apt/archives/texlive-fonts-recommended_2009-7_all.deb /var/cache/apt/archives/texlive-formats-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-full_2009-7_all.deb /var/cache/apt/archives/texlive-games_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-generic-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-generic-recommended_2009-7_all.deb /var/cache/apt/archives/texlive-humanities-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-humanities_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-lang-african_2009-3_all.deb /var/cache/apt/archives/texlive-lang-arabic_2009-3_all.deb /var/cache/apt/archives/texlive-lang-armenian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-croatian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-cyrillic_2009-3_all.deb /var/cache/apt/archives/texlive-lang-czechslovak_2009-3_all.deb /var/cache/apt/archives/texlive-lang-danish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-dutch_2009-3_all.deb /var/cache/apt/archives/texlive-lang-finnish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-french_2009-3_all.deb /var/cache/apt/archives/texlive-lang-german_2009-3_all.deb /var/cache/apt/archives/texlive-lang-greek_2009-3_all.deb /var/cache/apt/archives/texlive-lang-hebrew_2009-3_all.deb /var/cache/apt/archives/texlive-lang-hungarian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-indic_2009-3_all.deb /var/cache/apt/archives/texlive-lang-italian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-latin_2009-3_all.deb /var/cache/apt/archives/texlive-lang-latvian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-lithuanian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-mongolian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-norwegian_2009-3_all.deb /var/cache/apt/archives/texlive-lang-other_2009-3_all.deb /var/cache/apt/archives/texlive-lang-polish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-portuguese_2009-3_all.deb /var/cache/apt/archives/texlive-lang-spanish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-swedish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-tibetan_2009-3_all.deb /var/cache/apt/archives/texlive-lang-ukenglish_2009-3_all.deb /var/cache/apt/archives/texlive-lang-vietnamese_2009-3_all.deb /var/cache/apt/archives/texlive-latex-base-doc_2009-7_all.deb /var/cache/apt/archives/texlive-latex-base_2009-7_all.deb /var/cache/apt/archives/texlive-latex-extra-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-latex-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-latex-recommended-doc_2009-7_all.deb /var/cache/apt/archives/texlive-latex-recommended_2009-7_all.deb /var/cache/apt/archives/texlive-latex3_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-luatex_2009-7_all.deb /var/cache/apt/archives/texlive-math-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-metapost-doc_2009-7_all.deb /var/cache/apt/archives/texlive-metapost_2009-7_all.deb /var/cache/apt/archives/texlive-music_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-omega_2009-7_all.deb /var/cache/apt/archives/texlive-pictures-doc_2009-7_all.deb /var/cache/apt/archives/texlive-pictures_2009-7_all.deb /var/cache/apt/archives/texlive-plain-extra_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-pstricks-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-pstricks_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-publishers-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-publishers_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-science-doc_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-science_2009-7ubuntu3_all.deb /var/cache/apt/archives/texlive-xetex_2009-7_all.deb /var/cache/apt/archives/texlive_2009-7_all.deb /var/lib/dpkg/info/texlive-base.list /var/lib/dpkg/info/texlive-base.postrm /var/lib/dpkg/info/texlive-bibtex-extra.list /var/lib/dpkg/info/texlive-bibtex-extra.postrm /var/lib/dpkg/info/texlive-doc-base.list /var/lib/dpkg/info/texlive-doc-base.postrm /var/lib/dpkg/info/texlive-doc-bg.list /var/lib/dpkg/info/texlive-doc-bg.postrm /var/lib/dpkg/info/texlive-doc-cs+sk.list /var/lib/dpkg/info/texlive-doc-cs+sk.postrm /var/lib/dpkg/info/texlive-doc-de.list /var/lib/dpkg/info/texlive-doc-de.postrm /var/lib/dpkg/info/texlive-doc-en.list /var/lib/dpkg/info/texlive-doc-en.postrm /var/lib/dpkg/info/texlive-doc-es.list /var/lib/dpkg/info/texlive-doc-es.postrm /var/lib/dpkg/info/texlive-doc-fi.list /var/lib/dpkg/info/texlive-doc-fi.postrm /var/lib/dpkg/info/texlive-doc-fr.list /var/lib/dpkg/info/texlive-doc-fr.postrm /var/lib/dpkg/info/texlive-doc-it.list /var/lib/dpkg/info/texlive-doc-it.postrm /var/lib/dpkg/info/texlive-doc-ja.list /var/lib/dpkg/info/texlive-doc-ja.postrm /var/lib/dpkg/info/texlive-doc-ko.list /var/lib/dpkg/info/texlive-doc-ko.postrm /var/lib/dpkg/info/texlive-doc-mn.list /var/lib/dpkg/info/texlive-doc-mn.postrm /var/lib/dpkg/info/texlive-doc-nl.list /var/lib/dpkg/info/texlive-doc-nl.postrm /var/lib/dpkg/info/texlive-doc-pl.list /var/lib/dpkg/info/texlive-doc-pl.postrm /var/lib/dpkg/info/texlive-doc-pt.list /var/lib/dpkg/info/texlive-doc-pt.postrm /var/lib/dpkg/info/texlive-doc-ru.list /var/lib/dpkg/info/texlive-doc-ru.postrm /var/lib/dpkg/info/texlive-doc-si.list /var/lib/dpkg/info/texlive-doc-si.postrm /var/lib/dpkg/info/texlive-doc-th.list /var/lib/dpkg/info/texlive-doc-th.postrm /var/lib/dpkg/info/texlive-doc-tr.list /var/lib/dpkg/info/texlive-doc-tr.postrm /var/lib/dpkg/info/texlive-doc-uk.list /var/lib/dpkg/info/texlive-doc-uk.postrm /var/lib/dpkg/info/texlive-doc-vi.list /var/lib/dpkg/info/texlive-doc-vi.postrm /var/lib/dpkg/info/texlive-doc-zh.list /var/lib/dpkg/info/texlive-doc-zh.postrm /var/lib/dpkg/info/texlive-extra-utils.list /var/lib/dpkg/info/texlive-extra-utils.postrm /var/lib/dpkg/info/texlive-font-utils.list /var/lib/dpkg/info/texlive-font-utils.postrm /var/lib/dpkg/info/texlive-fonts-extra-doc.list /var/lib/dpkg/info/texlive-fonts-extra-doc.postrm /var/lib/dpkg/info/texlive-fonts-extra.list /var/lib/dpkg/info/texlive-fonts-extra.postrm /var/lib/dpkg/info/texlive-fonts-recommended-doc.list /var/lib/dpkg/info/texlive-fonts-recommended-doc.postrm /var/lib/dpkg/info/texlive-fonts-recommended.list /var/lib/dpkg/info/texlive-fonts-recommended.postrm /var/lib/dpkg/info/texlive-formats-extra.list /var/lib/dpkg/info/texlive-formats-extra.postrm /var/lib/dpkg/info/texlive-games.list /var/lib/dpkg/info/texlive-games.postrm /var/lib/dpkg/info/texlive-generic-extra.list /var/lib/dpkg/info/texlive-generic-extra.postrm /var/lib/dpkg/info/texlive-generic-recommended.list /var/lib/dpkg/info/texlive-generic-recommended.postrm /var/lib/dpkg/info/texlive-humanities-doc.list /var/lib/dpkg/info/texlive-humanities-doc.postrm /var/lib/dpkg/info/texlive-humanities.list /var/lib/dpkg/info/texlive-humanities.postrm /var/lib/dpkg/info/texlive-lang-african.list /var/lib/dpkg/info/texlive-lang-african.postrm /var/lib/dpkg/info/texlive-lang-arabic.list /var/lib/dpkg/info/texlive-lang-arabic.postrm /var/lib/dpkg/info/texlive-lang-armenian.list /var/lib/dpkg/info/texlive-lang-armenian.postrm /var/lib/dpkg/info/texlive-lang-croatian.list /var/lib/dpkg/info/texlive-lang-croatian.postrm /var/lib/dpkg/info/texlive-lang-cyrillic.list /var/lib/dpkg/info/texlive-lang-cyrillic.postrm /var/lib/dpkg/info/texlive-lang-czechslovak.list /var/lib/dpkg/info/texlive-lang-czechslovak.postrm /var/lib/dpkg/info/texlive-lang-danish.list /var/lib/dpkg/info/texlive-lang-danish.postrm /var/lib/dpkg/info/texlive-lang-dutch.list /var/lib/dpkg/info/texlive-lang-dutch.postrm /var/lib/dpkg/info/texlive-lang-finnish.list /var/lib/dpkg/info/texlive-lang-finnish.postrm /var/lib/dpkg/info/texlive-lang-french.list /var/lib/dpkg/info/texlive-lang-french.postrm /var/lib/dpkg/info/texlive-lang-german.list /var/lib/dpkg/info/texlive-lang-german.postrm /var/lib/dpkg/info/texlive-lang-greek.list /var/lib/dpkg/info/texlive-lang-greek.postrm /var/lib/dpkg/info/texlive-lang-hebrew.list /var/lib/dpkg/info/texlive-lang-hebrew.postrm /var/lib/dpkg/info/texlive-lang-hungarian.list /var/lib/dpkg/info/texlive-lang-hungarian.postrm /var/lib/dpkg/info/texlive-lang-indic.list /var/lib/dpkg/info/texlive-lang-indic.postrm /var/lib/dpkg/info/texlive-lang-italian.list /var/lib/dpkg/info/texlive-lang-italian.postrm /var/lib/dpkg/info/texlive-lang-latin.list /var/lib/dpkg/info/texlive-lang-latin.postrm /var/lib/dpkg/info/texlive-lang-latvian.list /var/lib/dpkg/info/texlive-lang-latvian.postrm /var/lib/dpkg/info/texlive-lang-lithuanian.list /var/lib/dpkg/info/texlive-lang-lithuanian.postrm /var/lib/dpkg/info/texlive-lang-mongolian.list /var/lib/dpkg/info/texlive-lang-mongolian.postrm /var/lib/dpkg/info/texlive-lang-norwegian.list /var/lib/dpkg/info/texlive-lang-norwegian.postrm /var/lib/dpkg/info/texlive-lang-other.list /var/lib/dpkg/info/texlive-lang-other.postrm /var/lib/dpkg/info/texlive-lang-polish.list /var/lib/dpkg/info/texlive-lang-polish.postrm /var/lib/dpkg/info/texlive-lang-portuguese.list /var/lib/dpkg/info/texlive-lang-portuguese.postrm /var/lib/dpkg/info/texlive-lang-spanish.list /var/lib/dpkg/info/texlive-lang-spanish.postrm /var/lib/dpkg/info/texlive-lang-swedish.list /var/lib/dpkg/info/texlive-lang-swedish.postrm /var/lib/dpkg/info/texlive-lang-tibetan.list /var/lib/dpkg/info/texlive-lang-tibetan.postrm /var/lib/dpkg/info/texlive-lang-ukenglish.list /var/lib/dpkg/info/texlive-lang-ukenglish.postrm /var/lib/dpkg/info/texlive-lang-vietnamese.list /var/lib/dpkg/info/texlive-lang-vietnamese.postrm /var/lib/dpkg/info/texlive-latex-base-doc.list /var/lib/dpkg/info/texlive-latex-base-doc.postrm /var/lib/dpkg/info/texlive-latex-base.list /var/lib/dpkg/info/texlive-latex-base.postrm /var/lib/dpkg/info/texlive-latex-extra-doc.list /var/lib/dpkg/info/texlive-latex-extra-doc.postrm /var/lib/dpkg/info/texlive-latex-extra.list /var/lib/dpkg/info/texlive-latex-extra.postrm /var/lib/dpkg/info/texlive-latex-recommended-doc.list /var/lib/dpkg/info/texlive-latex-recommended-doc.postrm /var/lib/dpkg/info/texlive-latex-recommended.list /var/lib/dpkg/info/texlive-latex-recommended.postrm /var/lib/dpkg/info/texlive-latex3.list /var/lib/dpkg/info/texlive-latex3.postrm /var/lib/dpkg/info/texlive-luatex.list /var/lib/dpkg/info/texlive-luatex.postrm /var/lib/dpkg/info/texlive-math-extra.list /var/lib/dpkg/info/texlive-math-extra.postrm /var/lib/dpkg/info/texlive-metapost-doc.list /var/lib/dpkg/info/texlive-metapost-doc.postrm /var/lib/dpkg/info/texlive-metapost.list /var/lib/dpkg/info/texlive-metapost.postrm /var/lib/dpkg/info/texlive-music.list /var/lib/dpkg/info/texlive-music.postrm /var/lib/dpkg/info/texlive-omega.list /var/lib/dpkg/info/texlive-omega.postrm /var/lib/dpkg/info/texlive-pictures-doc.list /var/lib/dpkg/info/texlive-pictures-doc.postrm /var/lib/dpkg/info/texlive-pictures.list /var/lib/dpkg/info/texlive-pictures.postrm /var/lib/dpkg/info/texlive-plain-extra.list /var/lib/dpkg/info/texlive-plain-extra.postrm /var/lib/dpkg/info/texlive-pstricks-doc.list /var/lib/dpkg/info/texlive-pstricks-doc.postrm /var/lib/dpkg/info/texlive-pstricks.list /var/lib/dpkg/info/texlive-pstricks.postrm /var/lib/dpkg/info/texlive-publishers-doc.list /var/lib/dpkg/info/texlive-publishers-doc.postrm /var/lib/dpkg/info/texlive-publishers.list /var/lib/dpkg/info/texlive-publishers.postrm /var/lib/dpkg/info/texlive-science-doc.list /var/lib/dpkg/info/texlive-science-doc.postrm /var/lib/dpkg/info/texlive-science.list /var/lib/dpkg/info/texlive-science.postrm /var/lib/dpkg/info/texlive-xetex.list /var/lib/dpkg/info/texlive-xetex.postrm maria@marysia-ubuntu:~$ I've used sudo apt-get autoclean without any change. I've installed deborphan and it showed nothing (maybe I've used it in wrong way: just entered command deborphan). Am I doing something wrong or I was told something which is not true? I would like to know two things: how to remove packages (if I'm doing it in wrong way) and how to clean hard disc from remains of all packages I've uninstalled till now (even if I don't remember what it was exactly). I have Ubuntu Tweak installed but I don't know how to use it and I think I prefere terminal commnands. Thanks

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• Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

  - by mortezam

  This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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