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  • Are long methods always bad?

    - by wobbily_col
    So looking around earlier I noticed some comments about long methods being bad practice. I am not sure I always agree that long methods are bad (and would like opinions from others). For example I have some Django views that do a bit of processing of the objects before sending them to the view, a long method being 350 lines of code. I have my code written so that it deals with the paramaters - sorting / filtering the queryset, then bit by bit does some processing on the objects my query has returned. So the processing is mainly conditional aggregation, that has complex enough rules it can't easily be done in the database, so I have some variables declared outside the main loop then get altered during the loop. varaible_1 = 0 variable_2 = 0 for object in queryset : if object.condition_condition_a and variable_2 > 0 : variable 1+= 1 ..... ... . more conditions to alter the variables return queryset, and context So according to the theory I should factor out all the code into smaller methods, so That I have the view method as being maximum one page long. However having worked on various code bases in the past, I sometimes find it makes the code less readable, when you need to constantly jump from one method to the next figuring out all the parts of it, while keeping the outermost method in your head. I find that having a long method that is well formatted, you can see the logic more easily, as it isn't getting hidden away in inner methods. I could factor out the code into smaller methods, but often there is is an inner loop being used for two or three things, so it would result in more complex code, or methods that don't do one thing but two or three (alternatively I could repeat inner loops for each task, but then there will be a performance hit). So is there a case that long methods are not always bad? Is there always a case for writing methods, when they will only be used in one place?

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  • Modular Web App Network Architecture

    - by nairware
    Assuming that I am dealing with dedicated physical servers or VPSs, is it conceivable and does it make sense to have distinct servers setup with the following roles to host a web application? Reverse Proxy Web server Application server Database server Specific points of interest: I am confused how to even separate the web and application servers. My understanding was that such 3-tier architectures were feasible. It is unclear to me if the app server would reside directly between the web and database server, or if the web server could directly interact with the database as well. The app server could either do the computational heavy-lifting on behalf of the app server or it could do heavy-lifting plus control all of the business logic (as implied in the diagram above, thus denying the web server of direct database access). I am also unsure what role the reverse proxy (ex. nginx) could and should fulfill as a web server, given the above mentioned setup. I know that nginx has web server features. But I do not know if it makes sense to have the reverse proxy be its own VPS, given that the web server–in theory–would be separate from the app server.

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  • VMware Kernel Module Updater hangs on Ubuntu 13.04

    VMware Player has a nice auto-detection of kernel changes, and requests the user to compile the required modules in order to load them. This happens from time to time after a regular update of your system. Usually, the dialog of VMware Kernel Module Updater pops up, asks for root access authentication, and completes the compilation. VMware Player or Workstation checks if modules for the active kernel are available. In theory this is supposed to work flawlessly but in reality there are pitfalls occassionally. With the recent upgrade to Ubuntu 13.04 Raring Ringtail and the latest kernel 3.8.0-21 the actual VMware Kernel Module Updater simply disappeared and the application wouldn't start as expected. When you launch VMware Player as super user (root) the dialog would stall like so: VMware Kernel Module Updater stalls while stopping the services Prior to version 5.x of VMware Player or version 7.x of VMware Workstation you would run a command like: $ sudo vmware-config.pl to resolve the module version conflict but this doesn't work anyway. Solution Instead, you have to execute the following line in a terminal or console window: $ sudo vmware-modconfig --console --install-all Those switches are (as of writing this article) not documented in the output of the --help switch. But VMware already documented this procedure in their knowledge base: VMware Workstation stops functioning after updating the kernel on a Linux host (1002411). Update As of today I had the first kernel upgrade to version 3.8.0-22 in Ubuntu 13.04. Don't even try it without vmware-modconfig...

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  • The conceptual process of populating related tables in a database (MySql) from a CSV file

    - by user322772
    I'm new to relational databases and all the material I've read covered primary and foreign keys, normal forms, and joins but left out to populate the database once it's created. How do you import a CSV file so the fields match their related table? Say you were tying to build a beer database and had a CSV file with each line as a record. Header: brewer, beer_name, country, city, state, beer_category, beer_type, alcohol_content Record 1: Anheuser-Busch, Budweiser, United States, St. Louis, Mo, Pale lager, Regular, 5.0% Record 2: Anheuser-Busch, Bud Light, United States, St. Louis, Mo, Pale lager Light, 4.2% Record 3: Miller Brewing Company, Miller Lite, United States, Milwaukee, WI, Pale lager, Light, 4.2% You can create a "Brewer" table and a "Beer" table. When importing how does you connect the primary keys between the tables?

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  • Efficient persistent storage for simple id to table of values map for java

    - by wds
    I need to store some data that follows the simple pattern of mapping an "id" to a full table (with multiple rows) of several columns (i.e. some integer values [u, v, w]). The size of one of these tables would be a couple of KB. Basically what I need is to store a persistent cache of some intermediary results. This could quite easily be implemented as simple sql, but there's a couple of problems, namely I need to compress the size of this structure on disk as much as possible. (because of amount of values I'm storing) Also, it's not transactional, I just need to write once and simply read the contents of the entire table, so a relational DB isn't actually a very good fit. I was wondering if anyone had any good suggestions? For some reason I can't seem to come up with something decent atm. Especially something with an API in java would be nice.

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  • Proper method to update and draw from game loop?

    - by Lost_Soul
    Recently I've took up the challenge for myself to create a basic 2d side scrolling monster truck game for my little brother. Which seems easy enough in theory. After working with XNA it seems strange jumping into Java (which is what I plan to program it in). Inside my game class I created a private class called GameLoop that extends from Runnable, then in the overridden run() method I made a while loop that handles time and such and I implemented a targetFPS for drawing as well. The loop looks like this: @Override public void run() { long fpsTime = 0; gameStart = System.currentTimeMillis(); lastTime = System.currentTimeMillis(); while(game.isGameRunning()) { currentTime = System.currentTimeMillis(); long ellapsedTime = currentTime - lastTime; if(mouseState.leftIsDown) { que.add(new Dot(mouseState.getPosition())); } entities.addAll(que); game.updateGame(ellapsedTime); fpsTime += ellapsedTime; if(fpsTime >= (1000 / targetedFPS)) { game.drawGame(ellapsedTime); } lastTime = currentTime; } The problem I've ran into is adding of entities after a click. I made a class that has another private class that extends MouseListener and MouseMotionListener then on changes I have it set a few booleans to tell me if the mouse is pressed or not which seems to work great but when I add the entity it throws a CME (Concurrent Modification Exception) sometimes. I have all the entities stored in a LinkedList so later I tried adding a que linkedlist where I later add the que to the normal list in the update loop. I think this would work fine if it was just the update method in the gameloop but with the repaint() method (called inside game.drawGame() method) it throws the CME. The only other thing is that I'm currently drawing directly from the overridden paintComponent() method in a custom class that extends JPanel. Maybe there is a better way to go about this? As well as fix my CME? Thanks in advance!!!

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  • Remove a certain value from string which keeps on changing

    - by user2971375
    I m trying to make a utility to generate a Insert script of sql tables along with relational table. I got all the values in c#. Now I want to remove the one column name and its value from the script.most probably the identity column. Eg. The string I have (which keeps on changing with table name and varies) INSERT Core.Customers ([customerId],[customername],[customeradress],[ordernumber]) Values(123,N'Rahul',N'244 LIZ MORN',2334) NOW I know I have to remove CustomerId. (sometimes need to be replaces with @somevariable) Please give me an efficient way how to retrieve customerId value and Deleting column name and value . Conditions: insert script length and columns names keep changing. Method should return the deleted value. At some point of time customer id can be same as order id. In that case my string.remove method fails.

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  • What to read as a good intro and quickstart to aspect-oriented programming and metaprogramming?

    - by Ivan
    As I've found myself repeating myself a lot, writing very similar queries and classes for different entities (despite of doing strong object and relational normalisation), etc, I've came to an Idea that I could and should automate the most of this and write an engine which will compile simple declarative models I specify into all the code limiting my job to describe the task and and finally just customise the result as needed. As far as I know this is about metaprogramming and aspect-oriented programming. How do I get acquainted with modern tools available quickly so that I don't invent one more bicycle developing my own?

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  • What mail storage should I choose for our web application; IMAP, key-valud store, rdbms, ...

    - by tvrtko
    I have to store e-mail messages for use with our application. I have "metadata" for all messages inside a relational database, but I don't feel comfortable keeping message content (gigabytes and terabytes of email data) inside a database. I'm currently using IMAP as a storage, but I have my doubts if I choose correctly. First of all there is a problem of uidvalidity and how to keep a permanent reference to message inside IMAP. Second, I'm not sure if this is the most robust solution in terms of backup/restore strategies, corruption of store, replication ... Positive side is that I can query IMAP using the headers because the data is mostly indexed. I don't know if key-value stores are a better approach (Casandra, Tokyo cabinet, redis). How they handle storing 1KB and 50MB of data. How they prevent corruption and when corruption or device failure happens how can I repair the store.

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  • Entity framework and database logic.

    - by Xavier Devian
    Hi all, i have a question that's being around for several years. As all you know entity framework is an ORM tool that tries to model the database to an object oriented access model. All the samples I've seen are quering directly to the database tables. So, which is the role of the views in the database now?. The views were used to model the database in a more friendly way, that is, several physical tables, one logic table. This was great for example in hidding the complex relational model on stored procedures as queryng the views inside them was much easier than reproducing the query joins over and over on each stored procedure. So the question is, why is entity framework so good if stored procedures can not take benefit of it?

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  • Pros and cons of sorting data in DB?

    - by Roman
    Let's assume I have a table with field of type VARCHAR. And I need to get data from that table sorted alphabetically by that field. What is the best way (for performance): add sort by field to the SQL-query or sort the data when it's already fetched? I'm using Java (with Hibernate), but I can't tell anything about DB engine. It could be any popular relational database (like MySQL or MS Sql Server or Oracle or HSQL DB or any other). The amount of records in table can vary greatly but let's assume there are 5k records.

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  • Windows Phone7 Development: Selecting target SDK(OS) version

    - by JibW
    I am a bit confusing in selecting the target version in Windows phone7 Application development. In my Windows phone7 app I need to use a light weight relational DB Which didn't introduce with version 7.0 but SQL CE with 7.1 version. The problem is if I select the target version as 7.1, then the devices which came up with windows phone7 OS 7.0 will not be able to install this. But I heard that all the devices that came with windows phone7 OS version 7.0 is upgradable for windows OS version 7.1 for free. If this is the case then if I select the development SDK version as 7.1, then will all the windows phone7 devices be able to install this? Like to know which will be the best Target version in this case to select, before I start developing. Any guidance/ Idea is highly appreciated. Thanks...

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  • Making OR/M loosely coupled and abstracted away from other layers.

    - by Genuine
    Hi all. In an n-tier architecture, the best place to put an object-relational mapping (OR/M) code is in the data access layer. For example, database queries and updates can be delegated to a tool like NHibernate. Yet, I'd like to keep all references to NHibernate within the data access layer and abstract dependencies away from the layers below or above it. That way, I can swap or plug in another OR/M tool (e.g. Entity Framework) or some approach (e.g. plain vanilla stored procedure calls, mock objects) without causing compile-time errors or a major overhaul of the entire application. Testability is an added bonus. Could someone please suggest a wrapper (i.e. an interface or base class) or approach that would keep OR/M loosely coupled and contained in 1 layer? Or point me to resources that would help? Thanks.

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  • Has anyone used an object database with a large amount of data?

    - by Jon Kruger
    Object databases like MongoDB and db4o are getting lots of pub lately. Everyone that plays with them seems to love it. I'm guessing that they are dealing with about 640K of data in their sample apps. Has anyone tried to use an object database with a large amount of data (say, 50GB or more)? Are you able to still execute complex queries against it (like from a search screen)? How does it compare to your usual relational database of choice? I'm just curious. I want to take the object database plunge, but I need to know if it'll work on something more than a sample app.

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  • What are some "mental steps" a developer must take to begin moving from SQL to NO-SQL (CouchDB, Fath

    - by Byron Sommardahl
    I have my mind firmly wrapped around relational databases and how to code efficiently against them. Most of my experience is with MySQL and SQL. I like many of the things I'm hearing about document-based databases, especially when someone in a recent podcast mentioned huge performance benefits. So, if I'm going to go down that road, what are some of the mental steps I must take to shift from SQL to NO-SQL? If it makes any difference in your answer, I'm a C# developer primarily (today, anyhow). I'm used to ORM's like EF and Linq to SQL. Before ORMs, I rolled my own objects with generics and datareaders. Maybe that matters, maybe it doesn't. Here are some more specific: How do I need to think about joins? How will I query without a SELECT statement? What happens to my existing stored objects when I add a property in my code? (feel free to add questions of your own here)

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  • Can I expose MySQL data using PHP and OData?

    - by user359796
    As I understand it, OData is just a standardized way to expose relational data RESTfully. If I've got a PHP application, it should be able to process those RESTful requests and manipulate a MySQL database based on the request data and then return an ATOM feed. First, are the preceeding statements correct? Second, does a PHP library to do this already exist or would I have to create my own? If I have completely misunderstood these technologies and my question doesn't make sense, please feel free to let me know.

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  • A simple example of movement prediction

    - by Daniel
    I've seen lots of examples of theory about the reason for client-side prediction, but I'm having a hard time converting it into code. I was wondering if someone knows of some specific examples that share some of the code, or can share their knowledge to shed some light into my situation. I'm trying to run some tests to get a the movement going (smoothly) between multiple clients. I'm using mouse input to initiate movement. I'm using AS3 and C# on a local Player.IO server. Right now I'm trying to get the Client side working, as I'm only forwarding position info with the client. I have 2 timers, one is an onEnterFrame and the other is a 100ms Timer, and one on mouseClick listener. When I click anywhere with a mouse, I update my player class to give it a destination point On every enterFrame Event for the player, it moves towards the destination point At every 100ms it sends a message to the server with the position of where it should be in a 100ms. The distance traveled is calculated by taking the distance (in Pixels) that the player can travel in one second, and dividing it by the framerate for the onEnterFrame handler, and by the update frequency (1/0.100s) for the server update. For the other Players, the location is interpolated and animated on every frame based on the new location. Is this the right way of doing it?

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  • SaaS Multi-tenancy Applications: How is data import/export/backup being implemented?

    - by Mark Redman
    How are applications providing import / export (or backups) of data in SaaS based multi-tenancy applications, particularly single database designs? Imports: Keeping things simple I think basic imports are useful, ie CSV to a spec (or a way of providing a mapping between CSV columns and fields in the database. Exports: In single database designs I have seen XML exports and HTML (basic sitse generated) exports of data? I would assume that XML is a better option? How does one cater for relational data? Would you reference various things within XML and provide documentation of the relationships or let users figurethis out? Are vendors providing an export/backup that can be imported back in/restored? Your comments appreciated.

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  • Zip Code to City/State and vice-versa in a database?

    - by Simucal
    I'm new to SQL and relational databases and I have what I would imagine is a common problem. I'm making a website and when each user submits a post they have to provide a location in either a zip code or a City/State. What is the best practice for handling this? Do I simply create a Zip Code and City and State table and query against them or are there ready made solutions for handling this? I'm using SQL Server 2005 if it makes a difference. I need to be able to retrieve a zip code given a city/state or I need to be able to spit out the city state given a zip code.

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  • What are some ways to separate game logic from animations and the draw loop?

    - by TMV
    I have only previously made flash games, using MovieClips and such to separate out my animations from my game logic. Now I am getting into trying my hand at making a game for Android, but the game programming theory around separating these things still confuses me. I come from a background of developing non game web applications so I am versed in more MVC like patterns and am stuck in that mindset as I approach game programming. I want to do things like abstract my game by having, for example, a game board class that contains the data for a grid of tiles with instances of a tile class that each contain properties. I can give my draw loop access to this and have it draw the game board based on the properties of each tile on the game board, but I don't understand where exactly animation should go. As far as I can tell, animation sort of sits between the abstracted game logic (model) and the draw loop (view). With my MVC mindset, it's frustrating trying to decide where animation is actually supposed to go. It would have quite a bit of data associated with it like a model, but seemingly needs to be very closely coupled with the draw loop in order to have things like frame independent animation. How can I break out of this mindset and start thinking about patterns that make more sense for games?

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  • Usual hibernate performance pitfall

    - by Antoine Claval
    Hi, We have just finish to profile our application. ( she's begin to be slow ). the problem seems to be "in hibernate". It's a legacy mapping. Who work's, and do it's job. The relational shema behind is ok too. But some request are slow as hell. So, we would appreciate any input on common and usual mistake made with hibernate who end up with slow response. Exemple : Eager in place of Lazy can change dramaticly the response time....

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  • Turn Based Event Algorithm

    - by GamersIncoming
    I'm currently working on a small roguelike in XNA, which sees the player in a randomly generated series of dungeons fending off creeps, as you might expect. As with most roguelikes, the player makes a move, and then each of the creeps currently active on screen will make a move in turns, until all creeps have updated, and it return's to the player's go. On paper, the simple algorithm is straightforward: Player takes turn Turn Number increments For each active creep, update Position Once all active creeps have updated, allow player to take next turn However, when it comes to actually writing this in more detail, the concept becomes a bit more tricky for me. So my question comes as this: what is the best way to handle events taking turns to trigger, where the completion of each last event triggers the next, when dealing with a large number of creeps (probably stored as an array of an enemy object), and is there an easier way to create some kind of engine that just takes all objects that need updating and chains them together so their updates follow suit? I'm not asking for code, just algorithms and theory in the direction of objects triggering updates one after the other, in a turn based manner. Thanks in advance. Edited: Here's the code I currently have that is horrible :/ if (player.getTurnOver() && updateWait == 0) { if (creep[creepToUpdate].getActive()) { creep[creepToUpdate].moveObject(player, map1); updateWait = 10; } if (creepToUpdate < creep.Length -1) { creepToUpdate++; } else { creepToUpdate = 0; player.setTurnOver(false); } } if (updateWait > 0) { updateWait--; }

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  • Good practices when optimizing HTML5/Javascript Game Developement [closed]

    - by hustlerinc
    I'm just starting out as a game developer and have created a few crappy but playable clones of classic games like pong, and bomberman. Being self taught (bless the internet) I do this by just stuffing in code to make the games work. Now I feel the time has come to create something complete, for this I need to know how a game is structured. I've searched on the web but there isn't that much to be found. The only "high-level" language I know is javascript so reading a tutorial or article based on C++ doesn't help me that much. I'm looking for good resource's pedagogically covering the theory and possibly examples (in Javascript or pseudo code that is understandable for a beginner) of how the game pieces fit together. From the start screen to asset loading and running the game loop. I'm not looking for anything complicated like reading through a 4000 line source code. All I want to learn is where, how and when the main parts of every game should be called. If you know any good resources to share, or maybe even have an answer for me I would deeply appreciate it.

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  • Why job postings always looking for "rockstars?" [closed]

    - by Xepoch
    I have noticed a recent trend in requesting programmers who are rockstars. I get it, they're looking for someone who is really good at what they do. But why (pray) make the reference to a rockstar? Do these companies really want these traits as a real rockstar? Party all night and wake up to take care of quick business in the morning? Substance abuse, Narcissism with celebrity, Compensation well exceeding their management, Excellent at putting on a short-lived show, Entertainment instead of value, 1 hit (project) wonders or single-genre performers, Et cetera What is wrong with Senior or Principal Software Engineer who has an established and proven passion for the business? Rather do we mean quite the opposite, someone who: rolls up the sleeves and gets to work, takes appropriate direction and helps influence teams, programs in lessons' learned and proper practices, provides timely communication to the whole team, can code and understand multiple languages, understands the science and theory behind computation, Is there a trend to diversify the software engineering ranks? How many software rockstars can you hire before your band starts breaking up? Sure, there are lots of folks doing this stuff on their own, maybe even a rare few who do coding for show, but I wager the majority is for business. I don't see ads for rockstar accountants, or rockstar machinists, or rockstart CFOs. What makes the software programmer and their hiring departments lean towards this kind of job title?

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  • Run Win7 Guest (raw disk) in Ubuntu (which was installed as Dual Boot on existing Win7)

    - by kingdango
    I installed Ubuntu 12.10 on top of Win 7 as a dual boot (awesome!). I'm hoping to use VirtualBox to run my original Win7 instance as a guest OS under Ubuntu. I found this existing question and followed the directions to no avail. I can get the VMDK file created but when I run it I just get a blank black screen with no additional information and Windows never loads. I see no HD activity or anything that would indicate it's loading. I used this command to create the VMDK file: VBoxManager internalcommands createrawvmdk -filename ~/.VirtualBox/Win7Native.vmdk -rawdisk /dev/sda3 It looks like everything was created correctly but I just get a blank screen when I run the VM. I do get this warning when I boot the VM: VirtualBox - Warning The virtual machine execution may run into and error condition as described below... The medium '/home/XXX/.VirtualBox/Win7Native.vmdk' has a logical size of 583GB but the file system the medium is located on can only handle up to 16GB in theory. We strongly recommend to put all your virtual disk images and the snapshot folder on a proper file system (e.g. etc3) with a sufficient size. ErrorId: Fat Partition Detected Severity: Warning How can I get this working?

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