directory loop - Page 920

Web Site Performance and Assembly Versioning – Part 2 Versioning Combined Files Using Subversion

- by capgpilk

Ok so it took a while to post this second part. Many apologies, we had a big roll out of a new platform at work and many things had to get sidelined. So this is the second part in a short series of website performance and using versioning to help improve it. Minification and Concatination of JavaScript and CSS Files Versioning Combined Files Using Subversion – this post Versioning Combined Files Using Mercurial – published shortly In the previous post we used AjaxMin to shrink js and css files then concatenated them into one file each which had the file name of site-script.combined.min.js and site-style.combined.min.css. These file names are fine, but you can configure IIS 7 to cache these static files and so lower the amount of data transferred between server and client. This is done by editing the response headers in IIS. 1. In IIS7 Manager, choose the directory where these files are located and select HTTP Response Headers. 2. Check the Expire Web Content and set a time period well into the future. 3. When refreshing the web page, the server will respond with HTTP 304 forcing the browser to retrieve the file from its cache. 4. As can be seen in FireBug, the Cache-Control header has a max age of 31536000 seconds which equates to 365 days. The server will always send this HTTP 304 message unless the file changes forcing it to send new content. To help force this we can change the file name based on the latest build using the SVN revision number in the filename. So we have lowered data transfer on content that hasn’t changed, but forced it to be sent when you have made a change to the css or js files. Now to get the SVN revision number in to the file name. 1. Import the MSBuildCommunityTasks targets which can be dowloaded from here. 1: <Import Project="$(MSBuildExtensionsPath) 2: \MSBuildCommunityTasks 3: \MSBuild.Community.Tasks.Targets" /> 2. Edit the BeforeBuild target to call out to svn and get the latest revision 1: <SvnVersion LocalPath="$(MSBuildProjectDirectory)" 2: ToolPath="$(ProgramFiles)\VisualSVN Server\bin"> 3: <Output TaskParameter="Revision" PropertyName="Revision" /> 4: </SvnVersion> 3. Set it to update the project AssemblyInfo.cs file for the svn revision. 1: <FileUpdate Files="Properties\AssemblyInfo.cs" 2: Regex="(\d+)\.(\d+)\.(\d+)\.(\d+)" 3: ReplacementText="$1.$2.$3.$(Revision)" /> 4. Now edit the AfterBuild target to get the full dll version. You could combine these two steps and just get the version from svn, I am working on one project that updates the AssemblyInfo file and another project that allows manual editing of the file, but needs that version within the file name; so I just combined the two for this post. 1: <MSBuild.ExtensionPack.Framework.Assembly 2: TaskAction="GetInfo" 3: NetAssembly="$(OutputPath)\mydll.dll"> 4: <Output TaskParameter="OutputItems" ItemName="Info" /> 5: </MSBuild.ExtensionPack.Framework.Assembly> 6: <Message Text="Version: %(Info.AssemblyVersion)" 7: Importance="High" /> 5. Use this Info.AssemblyVersion to write out the combined css and js files as described in the last post. 1: <WriteLinestoFile File="Scripts\site-%(Info.AssemblyVersion).combined.min.js" 2: Lines="@(JSLinesSite)" Overwrite="true" /> In the next post I will cover doing the same, but for a Mercurial repository.

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Lessons from rewriting POP Forums for MVC, open source-like

- by Jeff

It has been a ton of work, interrupted over the last two years by unemployment, moving, a baby, failing to sell houses and other life events, but it's really exciting to see POP Forums v9 coming together. I'm not even sure when I decided to really commit to it as an open source project, but working on the same team as the CodePlex folks probably had something to do with it. Moving along the roadmap I set for myself, the app is now running on a quasi-production site... we launched MouseZoom last weekend. (That's a post-beta 1 build of the forum. There's also some nifty Silverlight DeepZoom goodness on that site.)I have to make a point to illustrate just how important starting over was for me. I started this forum thing for my sites in old ASP more than ten years ago. What a mess that stuff was, including SQL injection vulnerabilities and all kinds of crap. It went to ASP.NET in 2002, but even then, it felt a little too much like script. More than a year later, in 2003, I did an honest to goodness rewrite. If you've been in this business of writing code for any amount of time, you know how much you hate what you wrote a month ago, so just imagine that with seven years in between. The subsequent versions still carried a fair amount of crap, and that's why I had to start over, to make a clean break. Mind you, much of that crap is still running on some of my production sites in a stable manner, but it's a pain in the ass to maintain.So with that clean break, there is much that I have learned. These are a few of those lessons, in no particular order...Avoid shiny object syndromeOver the years, I've embraced new things without bothering to ask myself why. I remember spending the better part of a year trying to adapt this app to use the membership and profile API's in ASP.NET, just because they were there. They didn't solve any known problem. Early on in this version, I dabbled in exotic ORM's, even though I already had the fundamental SQL that I knew worked. I bloated up the client side code with all kinds of jQuery UI and plugins just because, and it got in the way. All the new shiny can be distracting, and I've come to realize that I've allowed it to be a distraction most of my professional life.Just query what you needI've spent a lot of time over-thinking how to query data. In the SQL world, this means exotic joins, special caches, the read-update-commit loop of ORM's, etc. There are times when you have to remind yourself that you aren't Facebook, you'll never be Facebook, and that databases are in fact intended to serve data. In a lot of projects, back in the day, I used to have these big, rich data objects and pass them all over the place, through various application tiers, when in reality, all I needed was some ID from the entity. I try to be mindful of how many queries hit the database on a given request, but I don't obsess over it. I just get what I need.Don't spend too much time worrying about your unit testsIf you've looked at any of the tests for POP Forums, you might offer an audible WTF. That's OK. There's a whole lot of mocking going on. In some cases, it points out where you're doing too much, and that's good for improving your design. In other cases it shows where your design sucks. But the biggest trap of unit testing is that you worry it should be prettier. That's a waste of time. When you write a test, in many cases before the production code, the important part is that you're testing the right thing. If you have to mock up a bunch of stuff to test the outcome, so be it, but it's not wasted time. You're still doing up the typical arrange-action-assert deal, and you'll be able to read that later if you need to.Get back to your HTTP rootsASP.NET Webforms did a reasonably decent job at abstracting us away from the stateless nature of the Web. A lot of people criticize it, but I think it all worked pretty well. These days, with MVC, jQuery, REST services, and what not, we've gone back to thinking about the wire. The nuts and bolts passing between our Web browser and server matters. This doesn't make things harder, in my opinion, it makes them easier. There is something incredibly freeing about how we approach development of Web apps now. HTTP is a really simple protocol, and the stuff we push through it, in particular HTML and JSON, are pretty simple too. The debugging points are really easy to trap and trace.Premature optimization is prematureI'll go back to the data thing for a moment. I've been known to look at a particular action or use case and stress about the number of calls that are made to the database. I'm not suggesting that it's a bad thing to keep these in mind, but if you worry about it outside of the context of the actual impact, you're wasting time. For example, I query the database for last read times in a forum separately of the user and the list of forums. The impact on performance barely exists. If I put it under load, exceeding the kind of load I expect, it still barely has an impact. Then consider it only counts for logged in users. The context of this "inefficient" action is that it doesn't matter. Did I mention I won't be Facebook?Solve your own problems firstThis is another trap I've fallen into. I've often thought about what other people might need for some feature or aspect of the app. In other words, I was willing to make design decisions based on non-existent data. How stupid is that? When I decided to truly open source this thing, building for myself first was a stated design goal. This app has to server the audiences of CoasterBuzz, MouseZoom and other sites first. In this development scenario, you don't have access to mountains of usability studies or user focus groups. You have to start with what you know.I'm sure there are other points I could make too. It has been a lot of fun to work on, and I look forward to evolving the UI as time goes on. That's where I hope to see more magic in the future.

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Downloading stuff from Oracle: an example

- by user12587121

Introduction Oracle has a lot of software on offer. Components of the stack can evolve at different rates and different versions of the components may be in use at any given time. All this means that even the process of downloading the bits you need can be somewhat daunting. Here, by way of example, and hopefully to convince you that there is method in the downloading madness, we describe how to go about downloading the bits for Oracle Identity Manager (OIM) 11.1.1.5.Firstly, a couple of preliminary points: Folks with Oracle products already installed and looking for bug fixes, patch bundles or patch sets would go directly to the Oracle support website. This Oracle document is a comprehensive description of the Oracle FMW download process and the licensing that applies to downloaded software. Downloading Oracle Identity Manager 11.1.1.5 To be sure we download the right versions, first locate the Certification Matrix for OIM 11.1.1.5: first go to the Fusion Certification Page then go to the “System Requirements and Supported Platforms for Oracle Identity and Access Management 11gR1” link. Let’s assume you have a 64 bit Linux Machine and an Oracle database already. Then our goal is to end up with a list of files like the following: jdk-6u29-linux-x64.bin (Java JDK)V26017-01.zip (the Repository Creation Utility to create the DB schemas)wls1035_generic.jar (the Weblogic Application Server)ofm_iam_generic_11.1.1.5.0_disk1_1of1.zip (the Identity Managament bits)ofm_soa_generic_11.1.1.5.0_disk1_1of2.zip (the SOA bits)ofm_soa_generic_11.1.1.5.0_disk1_2of2.zip jdevstudio11115install.exe (optional: JDeveloper IDE)soa-jdev-extension.zip (optional: SOA extensions for JDeveloper) Downloading the bits 1. Download the Java JDK, 64 bit version 1.6.0_24+.2. Download the RCU: here you will see that the RCU is mentioned on the Identity Management home page but no link is provided. Do not panic. Due to the amount and turnover of software available only the latest versions are available for download from the main Oracle site. Over time software gets moved on to the Oracle edelivery site and it is here that we find the RCU version we require: a. Go to edelivery: https://edelivery.oracle.com b. Choose Pack ‘ Oracle Fusion Middleware’ and ‘Linux x86-64’ c. Click on ‘Oracle Fusion Middleware 11g Media Pack for Linux x86-64’ d. Download: ‘Oracle Fusion Middleware Repository Creation Utility 11g (11.1.1.5.0) for Linux x86’ (V26017.zip) 3. Download the Weblogic Application Server: WLS 10.3.54. Download the Oracle Identity Manager bits: one point to clarify here is that currently the Identity Management bits come in two trains, essentially one for the Directory Services piece and the other for the Access Management and Identity Management parts. We need to be careful not to confuse the two, in particular to be clear which of the trains is being referred to by the documentation: a. So, with this in mind, go to ‘ Oracle Identity and Access Management (11.1.1.5.0)’ and download Disk1. 5. Download the SOA bits: a. Go to the edelivery area as for the RCU and download: i. Oracle SOA Suite 11g Patch Set 4 (11.1.1.5.0) (Part 1 of 2) ii. Oracle SOA Suite 11g Patch Set 4 (11.1.1.5.0) (Part 2 of 2) 6. You will want to download some development tooling (for plugins or BPEL workflow development): a. Download Jdeveloper 11.1.1.5 (11.1.1.6 may work but best to stick to the versions that correspond to the WLS version we are using) b. Go to the site for SOA tools and download the SOA Composite Editor 11.1.1.5 That’s it, you may proceed to the installation.

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Memory Efficient Windows SOA Server

- by Antony Reynolds

Installing a Memory Efficient SOA Suite 11.1.1.6 on Windows Server Well 11.1.1.6 is now available for download so I thought I would build a Windows Server environment to run it. I will minimize the memory footprint of the installation by putting all functionality into the Admin Server of the SOA Suite domain. Required Software 64-bit JDK SOA Suite If you want 64-bit then choose “Generic” rather than “Microsoft Windows 32bit JVM” or “Linux 32bit JVM” This has links to all the required software. If you choose “Generic” then the Repository Creation Utility link does not show, you still need this so change the platform to “Microsoft Windows 32bit JVM” or “Linux 32bit JVM” to get the software. Similarly if you need a database then you need to change the platform to get the link to XE for Windows or Linux. If possible I recommend installing a 64-bit JDK as this allows you to assign more memory to individual JVMs. Windows XE will work, but it is better if you can use a full Oracle database because of the limitations on XE that sometimes cause it to run out of space with large or multiple SOA deployments. Installation Steps The following flow chart outlines the steps required in installing and configuring SOA Suite. The steps in the diagram are explained below. 64-bit? Is a 64-bit installation required? The Windows & Linux installers will install 32-bit versions of the Sun JDK and JRockit. A separate JDK must be installed for 64-bit. Install 64-bit JDK The 64-bit JDK can be either Hotspot or JRockit. You can choose either JDK 1.7 or 1.6. Install WebLogic If you are using 64-bit then install WebLogic using “java –jar wls1036_generic.jar”. Make sure you include Coherence in the installation, the easiest way to do this is to accept the “Typical” installation. SOA Suite Required? If you are not installing SOA Suite then you can jump straight ahead and create a WebLogic domain. Install SOA Suite Run the SOA Suite installer and point it at the existing Middleware Home created for WebLogic. Note to run the SOA installer on Windows the user must have admin privileges. I also found that on Windows Server 2008R2 I had to start the installer from a command prompt with administrative privileges, granting it privileges when it ran caused it to ignore the jreLoc parameter. Database Available? Do you have access to a database into which you can install the SOA schema. SOA Suite requires access to an Oracle database (it is supported on other databases but I would always use an oracle database). Install Database I use an 11gR2 Oracle database to avoid XE limitations. Make sure that you set the database character set to be unicode (AL32UTF8). I also disabled the new security settings because they get in the way for a developer database. Don’t forget to check that number of processes is at least 150 and number of sessions is not set, or is set to at least 200 (in the DB init parameters). Run RCU The SOA Suite database schemas are created by running the Repository Creation Utility. Install the “SOA and BPM Infrastructure” component to support SOA Suite. If you keep the schema prefix as “DEV” then the config wizard is easier to complete. Run Config Wizard The Config wizard creates the domain which hosts the WebLogic server instances. To get a minimum footprint SOA installation choose the “Oracle Enterprise Manager” and “Oracle SOA Suite for developers” products. All other required products will be automatically selected. The “for developers” installs target the appropriate components at the AdminServer rather than creating a separate managed server to house them. This reduces the number of JVMs required to run the system and hence the amount of memory required. This is not suitable for anything other than a developer environment as it mixes the admin and runtime functions together in a single server. It also takes a long time to load all the required modules, making start up a slow process. If it exists I would recommend running the config wizard found in the “oracle_common/common/bin” directory under the middleware home. This should have access to all the templates, including SOA. If you also want to run BAM in the same JVM as everything else then you need to “Select Optional Configuration” for “Managed Servers, Clusters and Machines”. To target BAM at the AdminServer delete the “bam_server1” managed server that is created by default. This will result in BAM being targeted at the AdminServer. Installation Issues I had a few problems when I came to test everything in my mega-JVM. Following applications were not targeted and so I needed to target them at the AdminServer: b2bui composer Healthcare UI FMW Welcome Page Application (11.1.0.0.0) How Memory Efficient is It? On a Windows 2008R2 Server running under VirtualBox I was able to bring up both the 11gR2 database and SOA/BPM/BAM in 3G memory. I allocated a minimum 512M to the PermGen and a minimum of 1.5G for the heap. The setting from setSOADomainEnv are shown below: set DEFAULT_MEM_ARGS=-Xms1536m -Xmx2048m set PORT_MEM_ARGS=-Xms1536m -Xmx2048m set DEFAULT_MEM_ARGS=%DEFAULT_MEM_ARGS% -XX:PermSize=512m -XX:MaxPermSize=768m set PORT_MEM_ARGS=%PORT_MEM_ARGS% -XX:PermSize=512m -XX:MaxPermSize=768m I arrived at these numbers by monitoring JVM memory usage in JConsole. Task Manager showed total system memory usage at 2.9G – just below the 3G I allocated to the VM. Performance is not stellar but it runs and I could run JDeveloper alongside it on my 8G laptop, so in that sense it was a result!

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Is Linear Tape File System (LTFS) Best For Transportable Storage?

- by rickramsey

Those of us in tape storage engineering take a lot of pride in what we do, but understand that tape is the right answer to a storage problem only some of the time. And, unfortunately for a storage medium with such a long history, it has built up a few preconceived notions that are no longer valid. When I hear customers debate whether to implement tape vs. disk, one of the common strikes against tape is its perceived lack of usability. If you could go back a few generations of corporate acquisitions, you would discover that StorageTek engineers recognized this problem and started developing a solution where a tape drive could look just like a memory stick to a user. The goal was to not have to care about where files were on the cartridge, but to simply see the list of files that were on the tape, and click on them to open them up. Eventually, our friends in tape over at IBM built upon our work at StorageTek and Sun Microsystems and released the Linear Tape File System (LTFS) feature for the current LTO5 generation of tape drives as an open specification. LTFS is really a wonderful feature and we’re proud to have taken part in its beginnings and, as you’ll soon read, its future. Today we offer LTFS-Open Edition, which is free for you to use in your in Oracle Enterprise Linux 5.5 environment - not only on your LTO5 drives, but also on your Oracle StorageTek T10000C drives. You can download it free from Oracle and try it out. LTFS does exactly what its forefathers imagined. Now you can see immediately which files are on a cartridge. LTFS does this by splitting a cartridge into two partitions. The first holds all of the necessary metadata to create a directory structure for you to easily view the contents of the cartridge. The second partition holds all of the files themselves. When tape media is loaded onto a drive, a complete file system image is presented to the user. Adding files to a cartridge can be as simple as a drag-and-drop just as you do today on your laptop when transferring files from your hard drive to a thumb drive or with standard POSIX file operations. You may be thinking all of this sounds nice, but asking, “when will I actually use it?” As I mentioned at the beginning, tape is not the right solution all of the time. However, if you ever need to physically move data between locations, tape storage with LTFS should be your most cost-effective and reliable answer. I will give you a few use cases examples of when LTFS can be utilized. Media and Entertainment (M&E), Oil and Gas (O&G), and other industries have a strong need for their storage to be transportable. For example, an O&G company hunting for new oil deposits in remote locations takes very large underground seismic images which need to be shipped back to a central data center. M&E operations conduct similar activities when shooting video for productions. M&E companies also often transfers files to third-parties for editing and other activities. These companies have three highly flawed options for transporting data: electronic transfer, disk storage transport, or tape storage transport. The first option, electronic transfer, is impractical because of the expense of the bandwidth required to transfer multi-terabyte files reliably and efficiently. If there’s one place that has bandwidth, it’s your local post office so many companies revert to physically shipping storage media. Typically, M&E companies rely on transporting disk storage between sites even though it, too, is expensive. Tape storage should be the preferred format because as IDC points out, “Tape is more suitable for physical transportation of large amounts of data as it is less vulnerable to mechanical damage during transportation compared with disk" (See note 1, below). However, tape storage has not been used in the past because of the restrictions created by proprietary formats. A tape may only be readable if both the sender and receiver have the same proprietary application used to write the file. In addition, the workflows may be slowed by the need to read the entire tape cartridge during recall. LTFS solves both of these problems, clearing the way for tape to become the standard platform for transferring large files. LTFS is open and, as long as you’ve downloaded the free reader from our website or that of anyone in the LTO consortium, you can read the data. So if a movie studio ships a scene to a third-party partner to add, for example, sounds effects or a music score, it doesn’t have to care what technology the third-party has. If it’s written back to an LTFS-formatted tape cartridge, it can be read. Some tape vendors like to claim LTFS is a “standard,” but beauty is in the eye of the beholder. It’s a specification at this point, not a standard. That said, we’re already seeing application vendors create functionality to write in an LTFS format based on the specification. And it’s my belief that both customers and the tape storage industry will see the most benefit if we all follow the same path. As such, we have volunteered to lead the way in making LTFS a standard first with the Storage Network Industry Association (SNIA), and eventually through to standard bodies such as American National Standards Institute (ANSI). Expect to hear good news soon about our efforts. So, if storage transportability is one of your requirements, I recommend giving LTFS a look. It makes tape much more user-friendly and it’s free, which allows tape to maintain all of its cost advantages over disk! Note 1 - IDC Report. April, 2011. “IDC’s Archival Storage Solutions Taxonomy, 2011” - Brian Zents Website Newsletter Facebook Twitter

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XNA: Rotating Bones

- by MLM

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

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Write your Tests in RSpec with IronRuby

- by kazimanzurrashid

[Note: This is not a continuation of my previous post, treat it as an experiment out in the wild. ] Lets consider the following class, a fictitious Fund Transfer Service: public class FundTransferService : IFundTransferService { private readonly ICurrencyConvertionService currencyConvertionService; public FundTransferService(ICurrencyConvertionService currencyConvertionService) { this.currencyConvertionService = currencyConvertionService; } public void Transfer(Account fromAccount, Account toAccount, decimal amount) { decimal convertionRate = currencyConvertionService.GetConvertionRate(fromAccount.Currency, toAccount.Currency); decimal convertedAmount = convertionRate * amount; fromAccount.Withdraw(amount); toAccount.Deposit(convertedAmount); } } public class Account { public Account(string currency, decimal balance) { Currency = currency; Balance = balance; } public string Currency { get; private set; } public decimal Balance { get; private set; } public void Deposit(decimal amount) { Balance += amount; } public void Withdraw(decimal amount) { Balance -= amount; } } We can write the spec with MSpec + Moq like the following: public class When_fund_is_transferred { const decimal ConvertionRate = 1.029m; const decimal TransferAmount = 10.0m; const decimal InitialBalance = 100.0m; static Account fromAccount; static Account toAccount; static FundTransferService fundTransferService; Establish context = () => { fromAccount = new Account("USD", InitialBalance); toAccount = new Account("CAD", InitialBalance); var currencyConvertionService = new Moq.Mock<ICurrencyConvertionService>(); currencyConvertionService.Setup(ccv => ccv.GetConvertionRate(Moq.It.IsAny<string>(), Moq.It.IsAny<string>())).Returns(ConvertionRate); fundTransferService = new FundTransferService(currencyConvertionService.Object); }; Because of = () => { fundTransferService.Transfer(fromAccount, toAccount, TransferAmount); }; It should_decrease_from_account_balance = () => { fromAccount.Balance.ShouldBeLessThan(InitialBalance); }; It should_increase_to_account_balance = () => { toAccount.Balance.ShouldBeGreaterThan(InitialBalance); }; } and if you run the spec it will give you a nice little output like the following: When fund is transferred » should decrease from account balance » should increase to account balance 2 passed, 0 failed, 0 skipped, took 1.14 seconds (MSpec). Now, lets see how we can write exact spec in RSpec. require File.dirname(__FILE__) + "/../FundTransfer/bin/Debug/FundTransfer" require "spec" require "caricature" describe "When fund is transferred" do Convertion_Rate = 1.029 Transfer_Amount = 10.0 Initial_Balance = 100.0 before(:all) do @from_account = FundTransfer::Account.new("USD", Initial_Balance) @to_account = FundTransfer::Account.new("CAD", Initial_Balance) currency_convertion_service = Caricature::Isolation.for(FundTransfer::ICurrencyConvertionService) currency_convertion_service.when_receiving(:get_convertion_rate).with(:any, :any).return(Convertion_Rate) fund_transfer_service = FundTransfer::FundTransferService.new(currency_convertion_service) fund_transfer_service.transfer(@from_account, @to_account, Transfer_Amount) end it "should decrease from account balance" do @from_account.balance.should be < Initial_Balance end it "should increase to account balance" do @to_account.balance.should be > Initial_Balance end end I think the above code is self explanatory, treat the require(line 1- 4) statements as the add reference of our visual studio projects, we are adding all the required libraries with this statement. Next, the describe which is a RSpec keyword. The before does exactly the same as NUnit's Setup or MsTest’s TestInitialize attribute, but in the above we are using before(:all) which acts as ClassInitialize of MsTest, that means it will be executed only once before all the test methods. In the before(:all) we are first instantiating the from and to accounts, it is same as creating with the full name (including namespace) like fromAccount = new FundTransfer.Account(.., ..), next, we are creating a mock object of ICurrencyConvertionService, check that for creating the mock we are not using the Moq like the MSpec version. This is somewhat an interesting issue of IronRuby or maybe the DLR, it seems that it is not possible to use the lambda expression that most of the mocking tools uses in arrange phase in Iron Ruby, like: currencyConvertionService.Setup(ccv => ccv.GetConvertionRate(Moq.It.IsAny<string>(), Moq.It.IsAny<string>())).Returns(ConvertionRate); But the good news is, there is already an excellent mocking tool called Caricature written completely in IronRuby which we can use to mock the .NET classes. May be all the mocking tool providers should give some thought to add the support for the DLR, so that we can use the tool that we are already familiar with. I think the rest of the code is too simple, so I am skipping the explanation. Now, the last thing, how we are going to run it with RSpec, lets first install the required gems. Open you command prompt and type the following: igem sources -a http://gems.github.com This will add the GitHub as gem source. Next type: igem install uuidtools caricature rspec and at last we have to create a batch file so that we can execute it in the Notepad++, create a batch like in the IronRuby bin directory like my previous post and put the following in that batch file: @echo off cls call spec %1 --format specdoc pause Next, add a run menu and shortcut in the Notepad++ like my previous post. Now when we run it it will show the following output: When fund is transferred - should decrease from account balance - should increase to account balance Finished in 0.332042 seconds 2 examples, 0 failures Press any key to continue . . . You will complete code of this post in the bottom. That's it for today. Download: RSpecIntegration.zip

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Wednesday at OpenWorld: Identity Management

- by Tanu Sood

Divide and conquer! Yes, divide and conquer today at Oracle OpenWorld with your colleagues to make the most of all things Identity Management since there’s a lot going on. Here’ the line-up for today: Wednesday, October 3, 2012 CON9458: End End-User-Managed Passwords and Increase Security with Oracle Enterprise Single Sign-On Plus 10:15 a.m. – 11:15 a.m., Moscone West 3008 Most customers have a broad variety of applications (internal, external, web, client server, host etc) and single sign-on systems that extend to some, but not all systems. This session will focus on how customers are using enterprise single sign-on can help extend single sign-on to virtually any application, without costly application modification while laying a foundation that will enable integration with a broader identity management platform. CON9494: Sun2Oracle: Identity Management Platform Transformation 11:45 a.m. – 12:45 p.m., Moscone West 3008 Sun customers are actively defining strategies for how they will modernize their identity deployments. Learn how customers like Avea and SuperValu are leveraging their Sun investment, evaluating areas of expansion/improvement and building momentum. CON9631: Entitlement-centric Access to SOA and Cloud Services 11:45 a.m. – 12:45 p.m., Marriott Marquis, Salon 7 How do you enforce that a junior trader can submit 10 trades/day, with a total value of $5M, if market volatility is low? How can hide sensitive patient information from clerical workers but make it visible to specialists as long as consent has been given or there is an emergency? In this session, Uberether and HerbaLife take the stage with Oracle to demonstrate how you can enforce such entitlements on a service not just within your intranet but also right at the perimeter. CON3957 - Delivering Secure Wi-Fi on the Tube as an Olympics Legacy from London 2012 11:45 a.m. – 12:45 p.m., Moscone West 3003 In this session, Virgin Media, the U.K.’s first combined provider of broadband, TV, mobile, and home phone services, shares how it is providing free secure Wi-Fi services to the London Underground, using Oracle Virtual Directory and Oracle Entitlements Server, leveraging back-end legacy systems that were never designed to be externalized. As an Olympics 2012 legacy, the Oracle architecture will form a platform to be consumed by other Virgin Media services such as video on demand. CON9493: Identity Management and the Cloud 1:15 p.m. – 2:15 p.m., Moscone West 3008 Security is the number one barrier to cloud service adoption. Not so for industry leading companies like SaskTel, ConAgra foods and UPMC. This session will explore how these organizations are using Oracle Identity with cloud services and how some are offering identity management as a cloud service. CON9624: Real-Time External Authorization for Middleware, Applications, and Databases 3:30 p.m. – 4:30 p.m., Moscone West 3008 As organizations seek to grant access to broader and more diverse user populations, the importance of centrally defined and applied authorization policies become critical; both to identify who has access to what and to improve the end user experience. This session will explore how customers are using attribute and role-based access to achieve these goals. CON9625: Taking Control of WebCenter Security 5:00 p.m. – 6:00 p.m., Moscone West 3008 Many organizations are extending WebCenter in a business to business scenario requiring secure identification and authorization of business partners and their users. Leveraging LADWP’s use case, this session will focus on how customers are leveraging, securing and providing access control to Oracle WebCenter portal and mobile solutions. EVENTS: Identity Management Customer Advisory Board 2:30 p.m. – 3:30 p.m., Four Seasons – Yerba Buena Room This invitation-only event is designed exclusively for Customer Advisory Board (CAB) members to provide product strategy and roadmap updates. Identity Management Meet & Greet Networking Event 3:30 p.m. – 4:30 p.m., Meeting Session 4:30 p.m. – 5:30 p.m., Cocktail Reception Yerba Buena Room, Four Seasons Hotel, 757 Market Street, San Francisco The CAB meeting will be immediately followed by an open Meet & Greet event hosted by Oracle Identity Management executives and product management team. Do take this opportunity to network with your peers and connect with the Identity Management customers. For a complete listing, refer to the Focus on Identity Management document. And as always, you can find us on @oracleidm on twitter and FaceBook. Use #oow and #idm to join in the conversation.

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Monitoring your WCF Web Apis with AppFabric

- by cibrax

The other day, Ron Jacobs made public a template in the Visual Studio Gallery for enabling monitoring capabilities to any existing WCF Http service hosted in Windows AppFabric. I thought it would be a cool idea to reuse some of that for doing the same thing on the new WCF Web Http stack. Windows AppFabric provides a dashboard that you can use to dig into some metrics about the services usage, such as number of calls, errors or information about different events during a service call. Those events not only include information about the WCF pipeline, but also custom events that any developer can inject and make sense for troubleshooting issues. This monitoring capabilities can be enabled on any specific IIS virtual directory by using the AppFabric configuration tool or adding the following configuration sections to your existing web app, <system.serviceModel> <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" /> <diagnostics etwProviderId="3e99c707-3503-4f33-a62d-2289dfa40d41"> <endToEndTracing propagateActivity="true" messageFlowTracing="true" /> </diagnostics> <behaviors> <serviceBehaviors> <behavior name=""> <etwTracking profileName="EndToEndMonitoring Tracking Profile" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> <microsoft.applicationServer> <monitoring> <default enabled="true" connectionStringName="ApplicationServerMonitoringConnectionString" monitoringLevel="EndToEndMonitoring" /> </monitoring> </microsoft.applicationServer> Bad news is that none of the configuration above can be easily set on code by using the new configuration model for WCF Web stack. A good thing is that you easily disable it in the configuration when you no longer need it, and also uses ETW, a general-purpose and high-speed tracing facility provided by the operating system (it’s part of the windows kernel). By adding that configuration section, AppFabric will start monitoring your service automatically and providing some basic event information about the service calls. You need some custom code for injecting custom events in the monitoring data. What I did here is to copy and refactor the “WCFUserEventProvider” class provided as sample in the Ron’s template to make it more TDD friendly when using IoC. I created a simple interface “ILogger” that any service (or resource) can use to inject custom events or monitoring information in the AppFabric database. public interface ILogger { bool WriteError(string name, string format, params object[] args); bool WriteWarning(string name, string format, params object[] args); bool WriteInformation(string name, string format, params object[] args); } The “WCFUserEventProvider” class implements this interface by making possible to send the events to the AppFabric monitoring database. The service or resource implementation can receive an “ILogger” as part of the constructor. [ServiceContract] [Export] public class OrderResource { IOrderRepository repository; ILogger logger; [ImportingConstructor] public OrderResource(IOrderRepository repository, ILogger logger) { this.repository = repository; this.logger = logger; } [WebGet(UriTemplate = "{id}")] public Order Get(string id, HttpResponseMessage response) { var order = this.repository.All.FirstOrDefault(o => o.OrderId == int.Parse(id, CultureInfo.InvariantCulture)); if (order == null) { response.StatusCode = HttpStatusCode.NotFound; response.Content = new StringContent("Order not found"); } this.logger.WriteInformation("Order Requested", "Order Id {0}", id); return order; } } The example above uses “MEF” as IoC for injecting a repository and the logger implementation into the service. You can also see how the logger is used to write an information event in the monitoring database. The following image illustrates how the custom event is injected and the information becomes available for any user in the dashboard. An issue that you might run into and I hope the WCF and AppFabric teams fixed soon is that any WCF service that uses friendly URLs with ASP.NET routing does not get listed as a available service in the WCF services tab in the AppFabric console. The complete example is available to download from here.

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Windows Azure Recipe: Software as a Service (SaaS)

- by Clint Edmonson

The cloud was tailor built for aspiring companies to create innovative internet based applications and solutions. Whether you’re a garage startup with very little capital or a Fortune 1000 company, the ability to quickly setup, deliver, and iterate on new products is key to capturing market and mind share. And if you can capture that share and go viral, having resiliency and infinite scale at your finger tips is great peace of mind. Drivers Cost avoidance Time to market Scalability Solution Here’s a sketch of how a basic Software as a Service solution might be built out: Ingredients Web Role – this hosts the core web application. Each web role will host an instance of the software and as the user base grows, additional roles can be spun up to meet demand. Access Control – this service is essential to managing user identity. It’s backed by a full blown implementation of Active Directory and allows the definition and management of users, groups, and roles. A pre-built ASP.NET membership provider is included in the training kit to leverage this capability but it’s also flexible enough to be combined with external Identity providers including Windows LiveID, Google, Yahoo!, and Facebook. The provider model provides extensibility to hook into other industry specific identity providers as well. Databases – nearly every modern SaaS application is backed by a relational database for its core operational data. If the solution is sold to organizations, there’s a good chance multi-tenancy will be needed. An emerging best practice for SaaS applications is to stand up separate SQL Azure database instances for each tenant’s proprietary data to ensure isolation from other tenants. Worker Role – this is the best place to handle autonomous background processing such as data aggregation, billing through external services, and other specialized tasks that can be performed asynchronously. Placing these tasks in a worker role frees the web roles to focus completely on user interaction and data input and provides finer grained control over the system’s scalability and throughput. Caching (optional) – as a web site traffic grows caching can be leveraged to keep frequently used read-only, user specific, and application resource data in a high-speed distributed in-memory for faster response times and ultimately higher scalability without spinning up more web and worker roles. It includes a token based security model that works alongside the Access Control service. Blobs (optional) – depending on the nature of the software, users may be creating or uploading large volumes of heterogeneous data such as documents or rich media. Blob storage provides a scalable, resilient way to store terabytes of user data. The storage facilities can also integrate with the Access Control service to ensure users’ data is delivered securely. Training & Examples These links point to online Windows Azure training labs and examples where you can learn more about the individual ingredients described above. (Note: The entire Windows Azure Training Kit can also be downloaded for offline use.) Windows Azure (16 labs) Windows Azure is an internet-scale cloud computing and services platform hosted in Microsoft data centers, which provides an operating system and a set of developer services which can be used individually or together. It gives developers the choice to build web applications; applications running on connected devices, PCs, or servers; or hybrid solutions offering the best of both worlds. New or enhanced applications can be built using existing skills with the Visual Studio development environment and the .NET Framework. With its standards-based and interoperable approach, the services platform supports multiple internet protocols, including HTTP, REST, SOAP, and plain XML SQL Azure (7 labs) Microsoft SQL Azure delivers on the Microsoft Data Platform vision of extending the SQL Server capabilities to the cloud as web-based services, enabling you to store structured, semi-structured, and unstructured data. Windows Azure Services (9 labs) As applications collaborate across organizational boundaries, ensuring secure transactions across disparate security domains is crucial but difficult to implement. Windows Azure Services provides hosted authentication and access control using powerful, secure, standards-based infrastructure. Developing Applications for the Cloud, 2nd Edition (eBook) This book demonstrates how you can create from scratch a multi-tenant, Software as a Service (SaaS) application to run in the cloud using the latest versions of the Windows Azure Platform and tools. The book is intended for any architect, developer, or information technology (IT) professional who designs, builds, or operates applications and services that run on or interact with the cloud. Fabrikam Shipping (SaaS reference application) This is a full end to end sample scenario which demonstrates how to use the Windows Azure platform for exposing an application as a service. We developed this demo just as you would: we had an existing on-premises sample, Fabrikam Shipping, and we wanted to see what it would take to transform it in a full subscription based solution. The demo you find here is the result of that investigation See my Windows Azure Resource Guide for more guidance on how to get started, including more links web portals, training kits, samples, and blogs related to Windows Azure.

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Man pages not finding entry

- by Mike

So, I'm not sure what is going on with my system (ubuntu 12.04), but my man pages do not seem to be working. I try man gcc and get the following response No manual entry for gcc See 'man 7 undocumented' for help when manual pages are not available. However I see the man entry in /usr/share/man/man1/gcc.1.gz Here is what my /etc/manpath.config file looks like # manpath.config # # This file is used by the man-db package to configure the man and cat paths. # It is also used to provide a manpath for those without one by examining # their PATH environment variable. For details see the manpath(5) man page. # # Lines beginning with `#' are comments and are ignored. Any combination of # tabs or spaces may be used as `whitespace' separators. # # There are three mappings allowed in this file: # -------------------------------------------------------- # MANDATORY_MANPATH manpath_element # MANPATH_MAP path_element manpath_element # MANDB_MAP global_manpath [relative_catpath] #--------------------------------------------------------- # every automatically generated MANPATH includes these fields # #MANDATORY_MANPATH /usr/src/pvm3/man # MANDATORY_MANPATH /usr/man MANDATORY_MANPATH /usr/share/man MANDATORY_MANPATH /usr/local/share/man #--------------------------------------------------------- # set up PATH to MANPATH mapping # ie. what man tree holds man pages for what binary directory. # # *PATH* -> *MANPATH* # MANPATH_MAP /bin /usr/share/man MANPATH_MAP /usr/bin /usr/share/man MANPATH_MAP /sbin /usr/share/man MANPATH_MAP /usr/sbin /usr/share/man MANPATH_MAP /usr/local/bin /usr/local/man MANPATH_MAP /usr/local/bin /usr/local/share/man MANPATH_MAP /usr/local/sbin /usr/local/man MANPATH_MAP /usr/local/sbin /usr/local/share/man MANPATH_MAP /usr/X11R6/bin /usr/X11R6/man MANPATH_MAP /usr/bin/X11 /usr/X11R6/man MANPATH_MAP /usr/games /usr/share/man MANPATH_MAP /opt/bin /opt/man MANPATH_MAP /opt/sbin /opt/man #--------------------------------------------------------- # For a manpath element to be treated as a system manpath (as most of those # above should normally be), it must be mentioned below. Each line may have # an optional extra string indicating the catpath associated with the # manpath. If no catpath string is used, the catpath will default to the # given manpath. # # You *must* provide all system manpaths, including manpaths for alternate # operating systems, locale specific manpaths, and combinations of both, if # they exist, otherwise the permissions of the user running man/mandb will # be used to manipulate the manual pages. Also, mandb will not initialise # the database cache for any manpaths not mentioned below unless explicitly # requested to do so. # # In a per-user configuration file, this directive only controls the # location of catpaths and the creation of database caches; it has no effect # on privileges. # # Any manpaths that are subdirectories of other manpaths must be mentioned # *before* the containing manpath. E.g. /usr/man/preformat must be listed # before /usr/man. # # *MANPATH* -> *CATPATH* # MANDB_MAP /usr/man /var/cache/man/fsstnd MANDB_MAP /usr/share/man /var/cache/man MANDB_MAP /usr/local/man /var/cache/man/oldlocal MANDB_MAP /usr/local/share/man /var/cache/man/local MANDB_MAP /usr/X11R6/man /var/cache/man/X11R6 MANDB_MAP /opt/man /var/cache/man/opt # #--------------------------------------------------------- # Program definitions. These are commented out by default as the value # of the definition is already the default. To change: uncomment a # definition and modify it. # #DEFINE pager pager -s #DEFINE cat cat #DEFINE tr tr '\255\267\264\327' '\055\157\047\170' #DEFINE grep grep #DEFINE troff groff -mandoc #DEFINE nroff nroff -mandoc #DEFINE eqn eqn #DEFINE neqn neqn #DEFINE tbl tbl #DEFINE col col #DEFINE vgrind vgrind #DEFINE refer refer #DEFINE grap grap #DEFINE pic pic -S # #DEFINE compressor gzip -c7 #--------------------------------------------------------- # Misc definitions: same as program definitions above. # #DEFINE whatis_grep_flags -i #DEFINE apropos_grep_flags -iEw #DEFINE apropos_regex_grep_flags -iE #--------------------------------------------------------- # Section names. Manual sections will be searched in the order listed here; # the default is 1, n, l, 8, 3, 0, 2, 5, 4, 9, 6, 7. Multiple SECTION # directives may be given for clarity, and will be concatenated together in # the expected way. # If a particular extension is not in this list (say, 1mh), it will be # displayed with the rest of the section it belongs to. The effect of this # is that you only need to explicitly list extensions if you want to force a # particular order. Sections with extensions should usually be adjacent to # their main section (e.g. "1 1mh 8 ..."). # SECTION 1 n l 8 3 2 3posix 3pm 3perl 5 4 9 6 7 # #--------------------------------------------------------- # Range of terminal widths permitted when displaying cat pages. If the # terminal falls outside this range, cat pages will not be created (if # missing) or displayed. # #MINCATWIDTH 80 #MAXCATWIDTH 80 # # If CATWIDTH is set to a non-zero number, cat pages will always be # formatted for a terminal of the given width, regardless of the width of # the terminal actually being used. This should generally be within the # range set by MINCATWIDTH and MAXCATWIDTH. # #CATWIDTH 0 # #--------------------------------------------------------- # Flags. # NOCACHE keeps man from creating cat pages. #NOCACHE Thanks for any help (p.s. even 'man man' fails) Edit: When I run ls -l /usr/share/man/man1/gcc* I get the following output lrwxrwxrwx 1 root root 12 May 27 15:41 /usr/share/man/man1/gcc.1.gz -> gcc-4.6.1.gz -rw-r--r-- 1 root root 217776 Apr 15 17:34 /usr/share/man/man1/gcc-4.6.1.gz

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How to use Azure storage for uploading and displaying pictures.

- by Magnus Karlsson

Basic set up of Azure storage for local development and production. This is a somewhat completion of the following guide from http://www.windowsazure.com/en-us/develop/net/how-to-guides/blob-storage/ that also involves a practical example that I believe is commonly used, i.e. upload and present an image from a user. First we set up for local storage and then we configure for them to work on a web role. Steps: 1. Configure connection string locally. 2. Configure model, controllers and razor views. 1. Setup connectionsstring 1.1 Right click your web role and choose “Properties”. 1.2 Click Settings. 1.3 Add setting. 1.4 Name your setting. This will be the name of the connectionstring. 1.5 Click the ellipsis to the right. (the ellipsis appear when you mark the area. 1.6 The following window appears- Select “Windows Azure storage emulator” and click ok. Now we have a connection string to use. To be able to use it we need to make sure we have windows azure tools for storage. 2.1 Click Tools –> Library Package manager –> Manage Nuget packages for solution. 2.2 This is what it looks like after it has been added. Now on to what the code should look like. 3.1 First we need a view which collects images to upload. Here Index.cshtml. 1: @model List<string> 2: 3: @{ 4: ViewBag.Title = "Index"; 5: } 6: 7: <h2>Index</h2> 8: <form action="@Url.Action("Upload")" method="post" enctype="multipart/form-data"> 9: 10: <label for="file">Filename:</label> 11: <input type="file" name="file" id="file1" /> 12: <br /> 13: <label for="file">Filename:</label> 14: <input type="file" name="file" id="file2" /> 15: <br /> 16: <label for="file">Filename:</label> 17: <input type="file" name="file" id="file3" /> 18: <br /> 19: <label for="file">Filename:</label> 20: <input type="file" name="file" id="file4" /> 21: <br /> 22: <input type="submit" value="Submit" /> 23: 24: </form> 25: 26: @foreach (var item in Model) { 27: 28: <img src="@item" alt="Alternate text"/> 29: } 3.2 We need a controller to receive the post. Notice the “containername” string I send to the blobhandler. I use this as a folder for the pictures for each user. If this is not a requirement you could just call it container or anything with small characters directly when creating the container. 1: public ActionResult Upload(IEnumerable<HttpPostedFileBase> file) 2: { 3: BlobHandler bh = new BlobHandler("containername"); 4: bh.Upload(file); 5: var blobUris=bh.GetBlobs(); 6: 7: return RedirectToAction("Index",blobUris); 8: } 3.3 The handler model. I’ll let the comments speak for themselves. 1: public class BlobHandler 2: { 3: // Retrieve storage account from connection string. 4: CloudStorageAccount storageAccount = CloudStorageAccount.Parse( 5: CloudConfigurationManager.GetSetting("StorageConnectionString")); 6: 7: private string imageDirecoryUrl; 8: 9: /// <summary> 10: /// Receives the users Id for where the pictures are and creates 11: /// a blob storage with that name if it does not exist. 12: /// </summary> 13: /// <param name="imageDirecoryUrl"></param> 14: public BlobHandler(string imageDirecoryUrl) 15: { 16: this.imageDirecoryUrl = imageDirecoryUrl; 17: // Create the blob client. 18: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 19: 20: // Retrieve a reference to a container. 21: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 22: 23: // Create the container if it doesn't already exist. 24: container.CreateIfNotExists(); 25: 26: //Make available to everyone 27: container.SetPermissions( 28: new BlobContainerPermissions 29: { 30: PublicAccess = BlobContainerPublicAccessType.Blob 31: }); 32: } 33: 34: public void Upload(IEnumerable<HttpPostedFileBase> file) 35: { 36: // Create the blob client. 37: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 38: 39: // Retrieve a reference to a container. 40: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 41: 42: if (file != null) 43: { 44: foreach (var f in file) 45: { 46: if (f != null) 47: { 48: CloudBlockBlob blockBlob = container.GetBlockBlobReference(f.FileName); 49: blockBlob.UploadFromStream(f.InputStream); 50: } 51: } 52: } 53: } 54: 55: public List<string> GetBlobs() 56: { 57: // Create the blob client. 58: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 59: 60: // Retrieve reference to a previously created container. 61: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 62: 63: List<string> blobs = new List<string>(); 64: 65: // Loop over blobs within the container and output the URI to each of them 66: foreach (var blobItem in container.ListBlobs()) 67: blobs.Add(blobItem.Uri.ToString()); 68: 69: return blobs; 70: } 71: } 3.4 So, when the files have been uploaded we will get them to present them to out user in the index page. Pretty straight forward. In this example we only present the image by sending the Uri’s to the view. A better way would be to save them up in a view model containing URI, metadata, alternate text, and other relevant information but for this example this is all we need. 4. Now press F5 in your solution to try it out. You can see the storage emulator UI here: 4.1 If you get any exceptions or errors I suggest to first check if the service Is running correctly. I had problem with this and they seemed related to the installation and a reboot fixed my problems. 5. Set up for Cloud storage. To do this we need to add configuration for cloud just as we did for local in step one. 5.1 We need our keys to do this. Go to the windows Azure menagement portal, select storage icon to the right and click “Manage keys”. (Image from a different blog post though). 5.2 Do as in step 1.but replace step 1.6 with: 1.6 Choose “Manually entered credentials”. Enter your account name. 1.7 Paste your Account Key from step 5.1. and click ok. 5.3. Save, publish and run! Please feel free to ask any questions using the comments form at the bottom of this page. I will get back to you to help you solve any questions. Our consultancy agency also provides services in the Nordic regions if you would like any further support.

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How to install Sweetcron on XAMPP

- by Sushaantu

This tutorial will take you to the installation steps required to install Sweetcron in the XAMPP. I am taking the liberty to assume that you have already installed XAMPP. I First of all download sweetcron and copy the extracted “sweetcron” folder inside the htdocs folder in the XAMPP directory. You have to get few things in place before installing sweetcron: 1. Create a sweetcron database using Mysql. You can just put a name “sweetcron” and leave all the other settings such as Mysql connection collation as it is. Now that you have the database ready you can configure few settings before making sweetcron to work on XAMPP. 2. Open the config-sample PHP file with your text editor (something like Notepad++ or Komodo Edit is recommended) which is located in Sweetcron/system/application/config. You have to make few changes in it. a. In the first settings you have to edit the value of $config ['base_url']. The default value is “http://www.your-site.com”; and you have to change that into “http://localhost/sweetcron/”; b. You also have to change the deafult settings of $config ['uri_protocol']. The value that you will see is “REQUEST_URI”; but you need to change that into “AUTO”; c. Now that we have made all the changes you can rename the file from config_sample to just config. 3. Open the database-sample.php in the text editor. You need to make the edits regarding the databse in here. a. The values of the databse at the moment are like this: $db['default']['hostname'] = “localhost”; $db['default']['username'] = “”; $db['default']['password'] = “”; $db['default']['database'] = “”; $db['default']['dbdriver'] = “mysql”; $db['default']['dbprefix'] = “”; $db['default']['pconnect'] = TRUE; $db['default']['db_debug'] = TRUE; $db['default']['cache_on'] = FALSE; $db['default']['cachedir'] = “”; $db['default']['char_set'] = “utf8″; $db['default']['dbcollat'] = “utf8_general_ci”; You have to change that into $db['default']['hostname'] = “localhost”; $db['default']['username'] = “root”; $db['default']['password'] = “”; $db['default']['database'] = “sweetcron”; $db['default']['dbdriver'] = “mysql”; $db['default']['dbprefix'] = “”; $db['default']['pconnect'] = TRUE; $db['default']['db_debug'] = TRUE; $db['default']['cache_on'] = FALSE; $db['default']['cachedir'] = “”; $db['default']['char_set'] = “utf8″; $db['default']['dbcollat'] = “utf8_general_ci”; We have written the username as root along with the name of database (sweetcron in my case). Since I was not using any password in xampp for the sweetcron database so I have left the password option empty. You can make suitable changes according to your system. Write down your password in the third line if you are using one in xampp. b. Now that we have made all the edits we can change the file name from database-sample to just database. 4. That leaves us with only one setting and that is editing values in the .htaccess file with our text editor. The default values you will have in the .htaccess file are: Options +FollowSymLinks RewriteEngine On RewriteBase / RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?/$1 [L] and you just have to add “sweetcron” after Rewritebase in the third line. Options +FollowSymLinks RewriteEngine On RewriteBase /sweetcron RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?/$1 [L] 5. Now you are all set and done. You can access sweetcron in the localhost by going to http://localhost/sweetcron/ you will see some text on the top which would prompt you to click on one script. Click that script and behold, you have your sweetcrom installation on xampp ready. Further it will ask you to add deatils such as Lifestream name, username and email address. Fill those deatils and you will reach the admin panel.

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Configuration "diff" across Oracle WebCenter Sites instances

- by Mark Fincham-Oracle

Problem Statement With many Oracle WebCenter Sites environments - how do you know if the various configuration assets and settings are in sync across all of those environments? Background At Oracle we typically have a "W" shaped set of environments. For the "Production" environments we typically have a disaster recovery clone as well and sometimes additional QA environments alongside the production management environment. In the case of www.java.com we have 10 different environments. All configuration assets/settings (CSElements, Templates, Start Menus etc..) start life on the Development Management environment and are then published downstream to other environments as part of the software development lifecycle. Ensuring that each of these 10 environments has the same set of Templates, CSElements, StartMenus, TreeTabs etc.. is impossible to do efficiently without automation. Solution Summary The solution comprises of two components. A JSON data feed from each environment. A simple HTML page that consumes these JSON data feeds. Data Feed: Create a JSON WebService on each environment. The WebService is no more than a SiteEntry + CSElement. The CSElement queries various DB tables to obtain details of the assets/settings returning this data in a JSON feed. Report: Create a simple HTML page that uses JQuery to fetch the JSON feed from each environment and display the results in a table. Since all assets (CSElements, Templates etc..) are published between environments they will have the same last modified date. If the last modified date of an asset is different in the JSON feed or is mising from an environment entirely then highlight that in the report table. Example Solution Details Step 1: Create a Site Entry + CSElement that outputs JSON Site Entry & CSElement Setup The SiteEntry should be uncached so that the most recent configuration information is returned at all times. In the CSElement set the contenttype accordingly: Step 2: Write the CSElement Logic The basic logic, that we repeat for each asset or setting that we are interested in, is to query the DB using <ics:sql> and then loop over the resultset with <ics:listloop>. For example: <ics:sql sql="SELECT name,updateddate FROM Template WHERE status != 'VO'" listname="TemplateList" table="Template" /> "templates": [ <ics:listloop listname="TemplateList"> {"name":"<ics:listget listname="TemplateList" fieldname="name"/>", "modified":"<ics:listget listname="TemplateList" fieldname="updateddate"/>"}, </ics:listloop> ], A comprehensive list of SQL queries to fetch each configuration asset/settings can be seen in the appendix at the end of this article. For the generation of the JSON data structure you could use Jettison (the library ships with the 11.1.1.8 version of the product), native Java 7 capabilities or (as the above example demonstrates) you could roll-your-own JSON output but that is not advised. Step 3: Create an HTML Report The JavaScript logic looks something like this.. 1) Create a list of JSON feeds to fetch: ENVS['dev-mgmngt'] = 'http://dev-mngmnt.example.com/sites/ContentServer?d=&pagename=settings.json'; ENVS['dev-dlvry'] = 'http://dev-dlvry.example.com/sites/ContentServer?d=&pagename=settings.json'; ENVS['test-mngmnt'] = 'http://test-mngmnt.example.com/sites/ContentServer?d=&pagename=settings.json'; ENVS['test-dlvry'] = 'http://test-dlvry.example.com/sites/ContentServer?d=&pagename=settings.json'; 2) Create a function to get the JSON feeds: function getDataForEnvironment(url){ return $.ajax({ type: 'GET', url: url, dataType: 'jsonp', beforeSend: function (jqXHR, settings){ jqXHR.originalEnv = env; jqXHR.originalUrl = url; }, success: function(json, status, jqXHR) { console.log('....success fetching: ' + jqXHR.originalUrl); // store the returned data in ALLDATA ALLDATA[jqXHR.originalEnv] = json; }, error: function(jqXHR, status, e) { console.log('....ERROR: Failed to get data from [' + url + '] ' + status + ' ' + e); } }); } 3) Fetch each JSON feed: for (var env in ENVS) { console.log('Fetching data for env [' + env +'].'); var promisedData = getDataForEnvironment(ENVS[env]); promisedData.success(function (data) {}); } 4) For each configuration asset or setting create a table in the report For example, CSElements: 1) Get a list of unique CSElement names from all of the returned JSON data. 2) For each unique CSElement name, create a row in the table 3) Select 1 environment to represent the master or ideal state (e.g. "Everything should be like Production Delivery") 4) For each environment, compare the last modified date of this envs CSElement to the master. Highlight any differences in last modified date or missing CSElements. 5) Repeat... Appendix This section contains various SQL statements that can be used to retrieve configuration settings from the DB. Templates <ics:sql sql="SELECT name,updateddate FROM Template WHERE status != 'VO'" listname="TemplateList" table="Template" /> CSElements <ics:sql sql="SELECT name,updateddate FROM CSElement WHERE status != 'VO'" listname="CSEList" table="CSElement" /> Start Menus <ics:sql sql="select sm.id, sm.cs_name, sm.cs_description, sm.cs_assettype, sm.cs_assetsubtype, sm.cs_itemtype, smr.cs_rolename, p.name from StartMenu sm, StartMenu_Sites sms, StartMenu_Roles smr, Publication p where sm.id=sms.ownerid and sm.id=smr.cs_ownerid and sms.pubid=p.id order by sm.id" listname="startList" table="Publication,StartMenu,StartMenu_Roles,StartMenu_Sites"/> Publishing Configurations <ics:sql sql="select id, name, description, type, dest, factors from PubTarget" listname="pubTargetList" table="PubTarget" /> Tree Tabs <ics:sql sql="select tt.id, tt.title, tt.tooltip, p.name as pubname, ttr.cs_rolename, ttsect.name as sectname from TreeTabs tt, TreeTabs_Roles ttr, TreeTabs_Sect ttsect,TreeTabs_Sites ttsites LEFT JOIN Publication p on p.id=ttsites.pubid where p.id is not null and tt.id=ttsites.ownerid and ttsites.pubid=p.id and tt.id=ttr.cs_ownerid and tt.id=ttsect.ownerid order by tt.id" listname="treeTabList" table="TreeTabs,TreeTabs_Roles,TreeTabs_Sect,TreeTabs_Sites,Publication" /> Filters <ics:sql sql="select name,description,classname from Filters" listname="filtersList" table="Filters" /> Attribute Types <ics:sql sql="select id,valuetype,name,updateddate from AttrTypes where status != 'VO'" listname="AttrList" table="AttrTypes" /> WebReference Patterns <ics:sql sql="select id,webroot,pattern,assettype,name,params,publication from WebReferencesPatterns" listname="WebRefList" table="WebReferencesPatterns" /> Device Groups <ics:sql sql="select id,devicegroupsuffix,updateddate,name from DeviceGroup" listname="DeviceList" table="DeviceGroup" /> Site Entries <ics:sql sql="select se.id,se.name,se.pagename,se.cselement_id,se.updateddate,cse.rootelement from SiteEntry se LEFT JOIN CSElement cse on cse.id = se.cselement_id where se.status != 'VO'" listname="SiteList" table="SiteEntry,CSElement" /> Webroots <ics:sql sql="select id,name,rooturl,updatedby,updateddate from WebRoot" listname="webrootList" table="WebRoot" /> Page Definitions <ics:sql sql="select pd.id, pd.name, pd.updatedby, pd.updateddate, pd.description, pdt.attributeid, pa.name as nameattr, pdt.requiredflag, pdt.ordinal from PageDefinition pd, PageDefinition_TAttr pdt, PageAttribute pa where pd.status != 'VO' and pa.id=pdt.attributeid and pdt.ownerid=pd.id order by pd.id,pdt.ordinal" listname="pageDefList" table="PageDefinition,PageAttribute,PageDefinition_TAttr" /> FW_Application <ics:sql sql="select id,name,updateddate from FW_Application where status != 'VO'" listname="FWList" table="FW_Application" /> Custom Elements <ics:sql sql="select elementname from ElementCatalog where elementname like 'CustomElements%'" listname="elementList" table="ElementCatalog" />

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So you want a French Site?

- by juanlarios

I thought I would write a quick write up of how to create a french site in SharePoint 2007. I'm not talking about a Variation but just a plain French Site from the ground up. There were some gotchas that I felt were worth blogging about. First: go to Microsoft Telnet Article and follow the install instructions. Make sure that when you get to the download page that you select "French" as part of the drop down and you download and install the right language pack. I noticed that if you did not click the "change" button enven though I selected the 'french' language pack, it reverted back to the english language pack. Second: You will notice a couple of things. When you go to central admin you will see the following: Now you can pick between french site or english. You will get this if you install other language packs and they will be listed in the drop down. You will notice that you now have french headings and frech listings of sites. You see "Publishing" as a heading because I have a custom site definition that I deployed as a french site. Third: As you start navigating around and trying to create document libraries or sites you will start getting errors. Errors like the following: "Cannot make a cache safe URL for "SelectorControls.js", file not found. Please verify that the file exists under the layouts directory. " Troubleshoot issues with Windows SharePoint Services. Once you resolve the issue with this "js" file, you will find that there are other js files that are missing. The only problem is that if you are not fluent in French or the language you are trying to deploy, Well, you'll have a tough time understanding error messages as they will all be in the new language you are trying to deploy. So let's just talk about what happened when you installed the language pack. In the 12 Hive: 12/Template you will now see a 1033 folder and a 1036 folder. The 1036 folder is the folder that was created and added as part of the language pack. What the above error is saying is that now that it's looking at the 1036 folder, well, it's missing some files. The nice thing is that these files are included in the 1033 folder (which is the English Language Pack). Simply copy and paste the controls from the one folder to the other. There will be more than one conflict so you will have to move serveral controls over. Can't remember how many but simply add them as error messages come up. I had to add some navigation controls and some content selectors. Now that's all that you need to install the Frech Language pack anc reate site collections that are entirely in a another language. Do not mistake this with Variations, where you can have multiple language sites. For those of you doing a little bit extra with this, let me share what I was doing extra and what I needed to get it working for me. I had had a custom site definition which was obviously not showing up in my selection of french sites. I was under the impression that all sites in English would show up in french and that the sites were simply routed to a new Resource file for french content. And that is the case but there is a little extra that needs to be done if you have a custom site definition deployed: First: Under hive 12/Template/1033/XML there is a listing of site definition files that are deployed to the English side of things. If you navigate to 12/Template/1036/XML and open one of the site definitions you will see that they are similar and reference the existing site definitions installed on the server, except that they have some french added to descriptions and names. Simply copy the xml file of your custom template to the 1036 folder to have it show up as a selection when you select French as the dropdown entry when create a site colleciton. You can go ahead and change the description and name to suit the language it's under. Second: As part of my site definition, I packaed up several list templates, that were saved as STP files. When you navigate to the list template listing, well, the templates are for English sites, not French so I cannot create document libraries based on the template. What now? well here comes KWIzCom to the rescue! They seem to have put out a "STP language converter" where you can take a site template or list template and convert it to any target language you are after. It's a free download, Use it and you're good to go. One thing I will mention is that when I convereted the English documents I whent ahead and converted them to French-Canadien. And it didn't work! so I finally figured out that the French Version it was expecting in the french site was "French-France". Don't know why that is, it's just what needs to be done to get that working. When I did that, I was able to use the List templates that I created in the English site for the French Site. Hope it helps , good luck!

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Sliding collision response

- by dbostream

I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner boards of a hockey rink. In my latest attempt the puck does slide along the boards but there are some strange velocity behaviors. First of all the puck slows down a lot pretty much right away and then it slides for awhile and stops before exiting the corner. Even if I double the speed I get a similar behavior and the puck does not make it out of the corner. I used some ideas from this document http://www.peroxide.dk/papers/collision/collision.pdf. This is what I have: Update method called from the game loop when it is time to update the puck (I removed some irrelevant parts). I use two states (current, previous) which are used to interpolate the position during rendering. public override void Update(double fixedTimeStep) { /* Acceleration is set to 0 for now. */ Acceleration.Zero(); PreviousState = CurrentState; _collisionRecursionDepth = 0; CurrentState.Position = SlidingCollision(CurrentState.Position, CurrentState.Velocity * fixedTimeStep + 0.5 * Acceleration * fixedTimeStep * fixedTimeStep); /* Should not this be affected by a sliding collision? and not only the position. */ CurrentState.Velocity = CurrentState.Velocity + Acceleration * fixedTimeStep; Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private Vector2 SlidingCollision(Vector2 position, Vector2 velocity) { if(_collisionRecursionDepth > 5) return position; bool collisionFound = false; Vector2 futurePosition = position + velocity; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ if(!collisionFound) return futurePosition; /* If no collision was detected it is safe to move to the future position. */ /* It is not exactly the intersection point, but slightly before. */ Vector2 newPosition = intersectionPoint; /* oldVelocity is set to the distance from the newPosition(intersection point) to the position it had moved to had it not collided. */ Vector2 oldVelocity = futurePosition - newPosition; /* Project the distance left to move along the intersection normal. */ Vector2 newVelocity = oldVelocity - intersectionPointNormal * oldVelocity.DotProduct(intersectionPointNormal); if(newVelocity.LengthSq() < 0.001) return newPosition; /* If almost no speed, no need to continue. */ _collisionRecursionDepth++; return SlidingCollision(newPosition, newVelocity); } What am I doing wrong with the velocity? I have been staring at this for very long so I have gone blind. I have tried different values of recursion depth but it does not seem to make it better. Let me know if you need more information. I appreciate any help. EDIT: A combination of Patrick Hughes' and teodron's answers solved the velocity problem (I think), thanks a lot! This is the new code: I decided to use a separate recursion method now too since I don't want to recalculate the acceleration in each recursion. public override void Update(double fixedTimeStep) { Acceleration.Zero();// = CalculateAcceleration(fixedTimeStep); PreviousState = new MovingEntityState(CurrentState.Position, CurrentState.Velocity); CurrentState = SlidingCollision(CurrentState, fixedTimeStep); Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private MovingEntityState SlidingCollision(MovingEntityState state, double timeStep) { bool collisionFound = false; /* Calculate the next position given no detected collision. */ Vector2 futurePosition = state.Position + state.Velocity * timeStep; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ /* If no collision was detected it is safe to move to the future position. */ if (!collisionFound) return new MovingEntityState(futurePosition, state.Velocity); /* Set new position to the intersection point (slightly before). */ Vector2 newPosition = intersectionPoint; /* Project the new velocity along the intersection normal. */ Vector2 newVelocity = state.Velocity - 1.90 * intersectionPointNormal * state.Velocity.DotProduct(intersectionPointNormal); /* Calculate the time of collision. */ double timeOfCollision = Math.Sqrt((newPosition - state.Position).LengthSq() / (futurePosition - state.Position).LengthSq()); /* Calculate new time step, remaining time of full step after the collision * current time step. */ double newTimeStep = timeStep * (1 - timeOfCollision); return SlidingCollision(new MovingEntityState(newPosition, newVelocity), newTimeStep); } Even though the code above seems to slide the puck correctly please have a look at it. I have a few questions, if I don't multiply by 1.90 in the newVelocity calculation it doesn't work (I get a stack overflow when the puck enters the corner because the timeStep decreases very slowly - a collision is found early in every recursion), why is that? what does 1.90 really do and why 1.90? Also I have a new problem, the puck does not move parallell to the short side after exiting the curve; to be more exact it moves outside the rink (I am not checking for any collisions with the short side at the moment). When I perform the collision detection I first check that the puck is in the correct quadrant. For example bottom-right corner is quadrant four i.e. circleCenter.X < puck.X && circleCenter.Y puck.Y is this a problem? or should the short side of the rink be the one to make the puck go parallell to it and not the last collision in the corner? EDIT2: This is the code I use for collision detection, maybe it has something to do with the fact that I can't make the puck slide (-1.0) but only reflect (-2.0): /* Point is the current position (not the predicted one) and quadrant is 4 for the bottom-right corner for example. */ if (GeometryHelper.PointInCircleQuadrant(circleCenter, circleRadius, state.Position, quadrant)) { /* The line is: from = state.Position, to = futurePosition. So a collision is detected when from is inside the circle and to is outside. */ if (GeometryHelper.LineCircleIntersection2d(state.Position, futurePosition, circleCenter, circleRadius, intersectionPoint, quadrant)) { collisionFound = true; /* Set the intersection point to slightly before the real intersection point (I read somewhere this was good to do because of floting point precision, not sure exactly how much though). */ intersectionPoint = intersectionPoint - Vector2.NormalizeRet(state.Velocity) * 0.001; /* Normal at the intersection point. */ intersectionPointNormal = Vector2.NormalizeRet(circleCenter - intersectionPoint) } } When I set the intersection point, if I for example use 0.1 instead of 0.001 the puck travels further before it gets stuck, but for all values I have tried (including 0 - the real intersection point) it gets stuck somewhere (but I necessarily not get a stack overflow). Can something in this part be the cause of my problem? I can see why I get the stack overflow when using -1.0 when calculating the new velocity vector; but not how to solve it. I traced the time steps used in the recursion (initial time step is always 1/60 ~ 0.01666): Recursion depth Time step next recursive call [Start recursion, time step ~ 0.016666] 0 0,000985806527246773 [No collision, stop recursion] [Start recursion, time step ~ 0.016666] 0 0,0149596704364629 1 0,0144883449376379 2 0,0143155612984837 3 0,014224925727213 4 0,0141673917461608 5 0,0141265435314026 6 0,0140953966184117 7 0,0140704653746625 ...and so on. As you can see the collision is detected early in every recursive call which means the next time step decreases very slowly thus the recursion depth gets very big - stack overflow.

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Movement prediction for non-shooters

- by ShadowChaser

I'm working on an isometric 2D game with moderate-scale multiplayer, approximately 20-30 players connected at once to a persistent server. I've had some difficulty getting a good movement prediction implementation in place. Physics/Movement The game doesn't have a true physics implementation, but uses the basic principles to implement movement. Rather than continually polling input, state changes (ie/ mouse down/up/move events) are used to change the state of the character entity the player is controlling. The player's direction (ie/ north-east) is combined with a constant speed and turned into a true 3D vector - the entity's velocity. In the main game loop, "Update" is called before "Draw". The update logic triggers a "physics update task" that tracks all entities with a non-zero velocity uses very basic integration to change the entities position. For example: entity.Position += entity.Velocity.Scale(ElapsedTime.Seconds) (where "Seconds" is a floating point value, but the same approach would work for millisecond integer values). The key point is that no interpolation is used for movement - the rudimentary physics engine has no concept of a "previous state" or "current state", only a position and velocity. State Change and Update Packets When the velocity of the character entity the player is controlling changes, a "move avatar" packet is sent to the server containing the entity's action type (stand, walk, run), direction (north-east), and current position. This is different from how 3D first person games work. In a 3D game the velocity (direction) can change frame to frame as the player moves around. Sending every state change would effectively transmit a packet per frame, which would be too expensive. Instead, 3D games seem to ignore state changes and send "state update" packets on a fixed interval - say, every 80-150ms. Since speed and direction updates occur much less frequently in my game, I can get away with sending every state change. Although all of the physics simulations occur at the same speed and are deterministic, latency is still an issue. For that reason, I send out routine position update packets (similar to a 3D game) but much less frequently - right now every 250ms, but I suspect with good prediction I can easily boost it towards 500ms. The biggest problem is that I've now deviated from the norm - all other documentation, guides, and samples online send routine updates and interpolate between the two states. It seems incompatible with my architecture, and I need to come up with a better movement prediction algorithm that is closer to a (very basic) "networked physics" architecture. The server then receives the packet and determines the players speed from it's movement type based on a script (Is the player able to run? Get the player's running speed). Once it has the speed, it combines it with the direction to get a vector - the entity's velocity. Some cheat detection and basic validation occurs, and the entity on the server side is updated with the current velocity, direction, and position. Basic throttling is also performed to prevent players from flooding the server with movement requests. After updating its own entity, the server broadcasts an "avatar position update" packet to all other players within range. The position update packet is used to update the client side physics simulations (world state) of the remote clients and perform prediction and lag compensation. Prediction and Lag Compensation As mentioned above, clients are authoritative for their own position. Except in cases of cheating or anomalies, the client's avatar will never be repositioned by the server. No extrapolation ("move now and correct later") is required for the client's avatar - what the player sees is correct. However, some sort of extrapolation or interpolation is required for all remote entities that are moving. Some sort of prediction and/or lag-compensation is clearly required within the client's local simulation / physics engine. Problems I've been struggling with various algorithms, and have a number of questions and problems: Should I be extrapolating, interpolating, or both? My "gut feeling" is that I should be using pure extrapolation based on velocity. State change is received by the client, client computes a "predicted" velocity that compensates for lag, and the regular physics system does the rest. However, it feels at odds to all other sample code and articles - they all seem to store a number of states and perform interpolation without a physics engine. When a packet arrives, I've tried interpolating the packet's position with the packet's velocity over a fixed time period (say, 200ms). I then take the difference between the interpolated position and the current "error" position to compute a new vector and place that on the entity instead of the velocity that was sent. However, the assumption is that another packet will arrive in that time interval, and it's incredibly difficult to "guess" when the next packet will arrive - especially since they don't all arrive on fixed intervals (ie/ state changes as well). Is the concept fundamentally flawed, or is it correct but needs some fixes / adjustments? What happens when a remote player stops? I can immediately stop the entity, but it will be positioned in the "wrong" spot until it moves again. If I estimate a vector or try to interpolate, I have an issue because I don't store the previous state - the physics engine has no way to say "you need to stop after you reach position X". It simply understands a velocity, nothing more complex. I'm reluctant to add the "packet movement state" information to the entities or physics engine, since it violates basic design principles and bleeds network code across the rest of the game engine. What should happen when entities collide? There are three scenarios - the controlling player collides locally, two entities collide on the server during a position update, or a remote entity update collides on the local client. In all cases I'm uncertain how to handle the collision - aside from cheating, both states are "correct" but at different time periods. In the case of a remote entity it doesn't make sense to draw it walking through a wall, so I perform collision detection on the local client and cause it to "stop". Based on point #2 above, I might compute a "corrected vector" that continually tries to move the entity "through the wall" which will never succeed - the remote avatar is stuck there until the error gets too high and it "snaps" into position. How do games work around this?

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SQL SERVER – Weekly Series – Memory Lane – #034

- by Pinal Dave

Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity. If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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Creating a Training Lab on Windows Azure

- by Michael Stephenson

Originally posted on: http://geekswithblogs.net/michaelstephenson/archive/2013/06/17/153149.aspxThis week we are preparing for a training course that Alan Smith will be running for the support teams at one of my customers around Windows Azure. In order to facilitate the training lab we have a few prerequisites we need to handle. One of the biggest ones is that although the support team all have MSDN accounts the local desktops they work on are not ideal for running most of the labs as we want to give them some additional developer background training around Azure. Some recent Azure announcements really help us in this area: MSDN software can now be used on Azure VM You don't pay for Azure VM's when they are no longer used Since the support team only have limited experience of Windows Azure and the organisation also have an Enterprise Agreement we decided it would be best value for money to spin up a training lab in a subscription on the EA and then we can turn the machines off when we are done. At the same time we would be able to spin them back up when the users need to do some additional lab work once the training course is completed. In order to achieve this I wanted to create a powershell script which would setup my training lab. The aim was to create 18 VM's which would be based on a prebuilt template with Visual Studio and the Azure development tools. The script I used is described below The Start & Variables The below text will setup the powershell environment and some variables which I will use elsewhere in the script. It will also import the Azure Powershell cmdlets. You can see below that I will need to download my publisher settings file and know some details from my Azure account. At this point I will assume you have a basic understanding of Azure & Powershell so already know how to do this. Set-ExecutionPolicy Unrestrictedcls $startTime = get-dateImport-Module "C:\Program Files (x86)\Microsoft SDKs\Windows Azure\PowerShell\Azure\Azure.psd1"# Azure Publisher Settings $azurePublisherSettings = '<Your settings file>.publishsettings' # Subscription Details $subscriptionName = "<Your subscription name>" $defaultStorageAccount = "<Your default storage account>" # Affinity Group Details $affinityGroup = '<Your affinity group>' $dataCenter = 'West Europe' # From Get-AzureLocation # VM Details $baseVMName = 'TRN' $adminUserName = '<Your admin username>' $password = '<Your admin password>' $size = 'Medium' $vmTemplate = '<The name of your VM template image>' $rdpFilePath = '<File path to save RDP files to>' $machineSettingsPath = '<File path to save machine info to>' Functions In the next section of the script I have some functions which are used to perform certain actions. The first is called CreateVM. This will do the following actions: If the VM already exists it will be deleted Create the cloud service Create the VM from the template I have created Add an endpoint so we can RDP to them all over the same port Download the RDP file so there is a short cut the trainees can easily access the machine via Write settings for the machine to a log file function CreateVM($machineNo) { # Specify a name for the new VM $machineName = "$baseVMName-$machineNo" Write-Host "Creating VM: $machineName" # Get the Azure VM Image $myImage = Get-AzureVMImage $vmTemplate #If the VM already exists delete and re-create it $existingVm = Get-AzureVM -Name $machineName -ServiceName $serviceName if($existingVm -ne $null) { Write-Host "VM already exists so deleting it" Remove-AzureVM -Name $machineName -ServiceName $serviceName } "Creating Service" $serviceName = "bupa-azure-train-$machineName" Remove-AzureService -Force -ServiceName $serviceName New-AzureService -Location $dataCenter -ServiceName $serviceName Write-Host "Creating VM: $machineName" New-AzureQuickVM -Windows -name $machineName -ServiceName $serviceName -ImageName $myImage.ImageName -InstanceSize $size -AdminUsername $adminUserName -Password $password Write-Host "Updating the RDP endpoint for $machineName" Get-AzureVM -name $machineName -ServiceName $serviceName ` | Add-AzureEndpoint -Name RDP -Protocol TCP -LocalPort 3389 -PublicPort 550 ` | Update-AzureVM Write-Host "Get the RDP File for machine $machineName" $machineRDPFilePath = "$rdpFilePath\$machineName.rdp" Get-AzureRemoteDesktopFile -name $machineName -ServiceName $serviceName -LocalPath "$machineRDPFilePath" WriteMachineSettings "$machineName" "$serviceName" } The delete machine settings function is used to delete the log file before we start re-running the process. function DeleteMachineSettings() { Write-Host "Deleting the machine settings output file" [System.IO.File]::Delete("$machineSettingsPath"); } The write machine settings function will get the VM and then record its details to the log file. The importance of the log file is that I can easily provide the information for all of the VM's to our infrastructure team to be able to configure access to all of the VM's function WriteMachineSettings([string]$vmName, [string]$vmServiceName) { Write-Host "Writing to the machine settings output file" $vm = Get-AzureVM -name $vmName -ServiceName $vmServiceName $vmEndpoint = Get-AzureEndpoint -VM $vm -Name RDP $sb = new-object System.Text.StringBuilder $sb.Append("Service Name: "); $sb.Append($vm.ServiceName); $sb.Append(", "); $sb.Append("VM: "); $sb.Append($vm.Name); $sb.Append(", "); $sb.Append("RDP Public Port: "); $sb.Append($vmEndpoint.Port); $sb.Append(", "); $sb.Append("Public DNS: "); $sb.Append($vmEndpoint.Vip); $sb.AppendLine(""); [System.IO.File]::AppendAllText($machineSettingsPath, $sb.ToString()); } # end functions Rest of Script In the rest of the script it is really just the bit that orchestrates the actions we want to happen. It will load the publisher settings, select the Azure subscription and then loop around the CreateVM function and create 16 VM's Import-AzurePublishSettingsFile $azurePublisherSettings Set-AzureSubscription -SubscriptionName $subscriptionName -CurrentStorageAccount $defaultStorageAccount Select-AzureSubscription -SubscriptionName $subscriptionName DeleteMachineSettings "Starting creating Bupa International Azure Training Lab" $numberOfVMs = 16 for ($index=1; $index -le $numberOfVMs; $index++) { $vmNo = "$index" CreateVM($vmNo); } "Finished creating Bupa International Azure Training Lab" # Give it a Minute Start-Sleep -s 60 $endTime = get-date "Script run time " + ($endTime - $startTime) Conclusion As you can see there is nothing too fancy about this script but in our case of creating a small isolated training lab which is not connected to our corporate network then we can easily use this to provision the lab. Im sure if this is of use to anyone you can easily modify it to do other things with the lab environment too. A couple of points to note are that there are some soft limits in Azure about the number of cores and services your subscription can use. You may need to contact the Azure support team to be able to increase this limit. In terms of the real business value of this approach, it was not possible to use the existing desktops to do the training on, and getting some internal virtual machines would have been relatively expensive and time consuming for our ops team to do. With the Azure option we are able to spin these machines up for a temporary period during the training course and then throw them away when we are done. We expect the costing of this test lab to be very small, especially considering we have EA pricing. As a ball park I think my 18 lab VM training environment will cost in the region of $80 per day on our EA. This is a fraction of the cost of the creation of a single VM on premise.

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JDK bug migration: components and subcomponents

- by darcy

One subtask of the JDK migration from the legacy bug tracking system to JIRA was reclassifying bugs from a three-level taxonomy in the legacy system, (product, category, subcategory), to a fundamentally two-level scheme in our customized JIRA instance, (component, subcomponent). In the JDK JIRA system, there is technically a third project-level classification, but by design a large majority of JDK-related bugs were migrated into a single "JDK" project. In the end, over 450 legacy subcategories were simplified into about 120 subcomponents in JIRA. The 120 subcomponents are distributed among 17 components. A rule of thumb used was that a subcategory had to have at least 50 bugs in it for it to be retained. Below is a listing the component / subcomponent classification of the JDK JIRA project along with some notes and guidance on which OpenJDK email addresses cover different areas. Eventually, a separate incidents project to host new issues filed at bugs.sun.com will use a slightly simplified version of this scheme. The preponderance of bugs and subcomponents for the JDK are in library-related areas, with components named foo-libs and subcomponents primarily named after packages. While there was an overall condensation of subcomponents in the migration, in some cases long-standing informal divisions in core libraries based on naming conventions in the description were promoted to formal subcomponents. For example, hundreds of bugs in the java.util subcomponent whose descriptions started with "(coll)" were moved into java.util:collections. Likewise, java.lang bugs starting with "(reflect)" and "(proxy)" were moved into java.lang:reflect. client-libs (Predominantly discussed on 2d-dev and awt-dev and swing-dev.) 2d demo java.awt java.awt:i18n java.beans (See beans-dev.) javax.accessibility javax.imageio javax.sound (See sound-dev.) javax.swing core-libs (See core-libs-dev.) java.io java.io:serialization java.lang java.lang.invoke java.lang:class_loading java.lang:reflect java.math java.net java.nio (Discussed on nio-dev.) java.nio.charsets java.rmi java.sql java.sql:bridge java.text java.util java.util.concurrent java.util.jar java.util.logging java.util.regex java.util:collections java.util:i18n javax.annotation.processing javax.lang.model javax.naming (JNDI) javax.script javax.script:javascript javax.sql org.openjdk.jigsaw (See jigsaw-dev.) security-libs (See security-dev.) java.security javax.crypto (JCE: includes SunJCE/MSCAPI/UCRYPTO/ECC) javax.crypto:pkcs11 (JCE: PKCS11 only) javax.net.ssl (JSSE, includes javax.security.cert) javax.security javax.smartcardio javax.xml.crypto org.ietf.jgss org.ietf.jgss:krb5 other-libs corba corba:idl corba:orb corba:rmi-iiop javadb other (When no other subcomponent is more appropriate; use judiciously.) Most of the subcomponents in the xml component are related to jaxp. xml jax-ws jaxb javax.xml.parsers (JAXP) javax.xml.stream (JAXP) javax.xml.transform (JAXP) javax.xml.validation (JAXP) javax.xml.xpath (JAXP) jaxp (JAXP) org.w3c.dom (JAXP) org.xml.sax (JAXP) For OpenJDK, most JVM-related bugs are connected to the HotSpot Java virtual machine. hotspot (See hotspot-dev.) build compiler (See hotspot-compiler-dev.) gc (garbage collection, see hotspot-gc-dev.) jfr (Java Flight Recorder) jni (Java Native Interface) jvmti (JVM Tool Interface) mvm (Multi-Tasking Virtual Machine) runtime (See hotspot-runtime-dev.) svc (Servicability) test core-svc (See serviceability-dev.) debugger java.lang.instrument java.lang.management javax.management tools The full JDK bug database contains entries related to legacy virtual machines that predate HotSpot as well as retired APIs. vm-legacy jit (Sun Exact VM) jit_symantec (Symantec VM, before Exact VM) jvmdi (JVM Debug Interface ) jvmpi (JVM Profiler Interface ) runtime (Exact VM Runtime) Notable command line tools in the $JDK/bin directory have corresponding subcomponents. tools appletviewer apt (See compiler-dev.) hprof jar javac (See compiler-dev.) javadoc(tool) (See compiler-dev.) javah (See compiler-dev.) javap (See compiler-dev.) jconsole launcher updaters (Timezone updaters, etc.) visualvm Some aspects of JDK infrastructure directly affect JDK Hg repositories, but other do not. infrastructure build (See build-dev and build-infra-dev.) licensing (Covers updates to the third party readme, licenses, and similar files.) release_eng (Release engineering) staging (Staging of web pages related to JDK releases.) The specification subcomponent encompasses the formal language and virtual machine specifications. specification language (The Java Language Specification) vm (The Java Virtual Machine Specification) The code for the deploy and install areas is not currently included in OpenJDK. deploy deployment_toolkit plugin webstart install auto_update install servicetags In the JDK, there are a number of cross-cutting concerns whose organization is essentially orthogonal to other areas. Since these areas generally have dedicated teams working on them, it is easier to find bugs of interest if these bugs are grouped first by their cross-cutting component rather than by the affected technology. docs doclet guides hotspot release_notes tools tutorial embedded build hotspot libraries globalization locale-data translation performance hotspot libraries The list of subcomponents will no doubt grow over time, but my inclination is to resist that growth since the addition of each subcomponent makes the system as a whole more complicated and harder to use. When the system gets closer to being externalized, I plan to post more blog entries describing recommended use of various custom fields in the JDK project.

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How to store generated eigen faces for future face recognition?

- by user3237134

My code works in the following manner: 1.First, it obtains several images from the training set 2.After loading these images, we find the normalized faces,mean face and perform several calculation. 3.Next, we ask for the name of an image we want to recognize 4.We then project the input image into the eigenspace, and based on the difference from the eigenfaces we make a decision. 5.Depending on eigen weight vector for each input image we make clusters using kmeans command. Source code i tried: clear all close all clc % number of images on your training set. M=1200; %Chosen std and mean. %It can be any number that it is close to the std and mean of most of the images. um=60; ustd=32; %read and show images(bmp); S=[]; %img matrix for i=1:M str=strcat(int2str(i),'.jpg'); %concatenates two strings that form the name of the image eval('img=imread(str);'); [irow icol d]=size(img); % get the number of rows (N1) and columns (N2) temp=reshape(permute(img,[2,1,3]),[irow*icol,d]); %creates a (N1*N2)x1 matrix S=[S temp]; %X is a N1*N2xM matrix after finishing the sequence %this is our S end %Here we change the mean and std of all images. We normalize all images. %This is done to reduce the error due to lighting conditions. for i=1:size(S,2) temp=double(S(:,i)); m=mean(temp); st=std(temp); S(:,i)=(temp-m)*ustd/st+um; end %show normalized images for i=1:M str=strcat(int2str(i),'.jpg'); img=reshape(S(:,i),icol,irow); img=img'; end %mean image; m=mean(S,2); %obtains the mean of each row instead of each column tmimg=uint8(m); %converts to unsigned 8-bit integer. Values range from 0 to 255 img=reshape(tmimg,icol,irow); %takes the N1*N2x1 vector and creates a N2xN1 matrix img=img'; %creates a N1xN2 matrix by transposing the image. % Change image for manipulation dbx=[]; % A matrix for i=1:M temp=double(S(:,i)); dbx=[dbx temp]; end %Covariance matrix C=A'A, L=AA' A=dbx'; L=A*A'; % vv are the eigenvector for L % dd are the eigenvalue for both L=dbx'*dbx and C=dbx*dbx'; [vv dd]=eig(L); % Sort and eliminate those whose eigenvalue is zero v=[]; d=[]; for i=1:size(vv,2) if(dd(i,i)>1e-4) v=[v vv(:,i)]; d=[d dd(i,i)]; end end %sort, will return an ascending sequence [B index]=sort(d); ind=zeros(size(index)); dtemp=zeros(size(index)); vtemp=zeros(size(v)); len=length(index); for i=1:len dtemp(i)=B(len+1-i); ind(i)=len+1-index(i); vtemp(:,ind(i))=v(:,i); end d=dtemp; v=vtemp; %Normalization of eigenvectors for i=1:size(v,2) %access each column kk=v(:,i); temp=sqrt(sum(kk.^2)); v(:,i)=v(:,i)./temp; end %Eigenvectors of C matrix u=[]; for i=1:size(v,2) temp=sqrt(d(i)); u=[u (dbx*v(:,i))./temp]; end %Normalization of eigenvectors for i=1:size(u,2) kk=u(:,i); temp=sqrt(sum(kk.^2)); u(:,i)=u(:,i)./temp; end % show eigenfaces; for i=1:size(u,2) img=reshape(u(:,i),icol,irow); img=img'; img=histeq(img,255); end % Find the weight of each face in the training set. omega = []; for h=1:size(dbx,2) WW=[]; for i=1:size(u,2) t = u(:,i)'; WeightOfImage = dot(t,dbx(:,h)'); WW = [WW; WeightOfImage]; end omega = [omega WW]; end % Acquire new image % Note: the input image must have a bmp or jpg extension. % It should have the same size as the ones in your training set. % It should be placed on your desktop ed_min=[]; srcFiles = dir('G:\newdatabase\*.jpg'); % the folder in which ur images exists for b = 1 : length(srcFiles) filename = strcat('G:\newdatabase\',srcFiles(b).name); Imgdata = imread(filename); InputImage=Imgdata; InImage=reshape(permute((double(InputImage)),[2,1,3]),[irow*icol,1]); temp=InImage; me=mean(temp); st=std(temp); temp=(temp-me)*ustd/st+um; NormImage = temp; Difference = temp-m; p = []; aa=size(u,2); for i = 1:aa pare = dot(NormImage,u(:,i)); p = [p; pare]; end InImWeight = []; for i=1:size(u,2) t = u(:,i)'; WeightOfInputImage = dot(t,Difference'); InImWeight = [InImWeight; WeightOfInputImage]; end noe=numel(InImWeight); % Find Euclidean distance e=[]; for i=1:size(omega,2) q = omega(:,i); DiffWeight = InImWeight-q; mag = norm(DiffWeight); e = [e mag]; end ed_min=[ed_min MinimumValue]; theta=6.0e+03; %disp(e) z(b,:)=InImWeight; end IDX = kmeans(z,5); clustercount=accumarray(IDX, ones(size(IDX))); disp(clustercount); QUESTIONS: 1.It is working fine for M=50(i.e Training set contains 50 images) but not for M=1200(i.e Training set contains 1200 images).It is not showing any error.There is no output.I waited for 10 min still there is no output. I think it is going infinite loop.What is the problem?Where i was wrong? 2.Instead of running the training set everytime how eigen faces generated are stored so that stored eigen faces are used for future face recoginition for a new input image.So it reduces wastage of time.

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Vectorization of matlab code for faster execution

- by user3237134

My code works in the following manner: 1.First, it obtains several images from the training set 2.After loading these images, we find the normalized faces,mean face and perform several calculation. 3.Next, we ask for the name of an image we want to recognize 4.We then project the input image into the eigenspace, and based on the difference from the eigenfaces we make a decision. 5.Depending on eigen weight vector for each input image we make clusters using kmeans command. Source code i tried: clear all close all clc % number of images on your training set. M=1200; %Chosen std and mean. %It can be any number that it is close to the std and mean of most of the images. um=60; ustd=32; %read and show images(bmp); S=[]; %img matrix for i=1:M str=strcat(int2str(i),'.jpg'); %concatenates two strings that form the name of the image eval('img=imread(str);'); [irow icol d]=size(img); % get the number of rows (N1) and columns (N2) temp=reshape(permute(img,[2,1,3]),[irow*icol,d]); %creates a (N1*N2)x1 matrix S=[S temp]; %X is a N1*N2xM matrix after finishing the sequence %this is our S end %Here we change the mean and std of all images. We normalize all images. %This is done to reduce the error due to lighting conditions. for i=1:size(S,2) temp=double(S(:,i)); m=mean(temp); st=std(temp); S(:,i)=(temp-m)*ustd/st+um; end %show normalized images for i=1:M str=strcat(int2str(i),'.jpg'); img=reshape(S(:,i),icol,irow); img=img'; end %mean image; m=mean(S,2); %obtains the mean of each row instead of each column tmimg=uint8(m); %converts to unsigned 8-bit integer. Values range from 0 to 255 img=reshape(tmimg,icol,irow); %takes the N1*N2x1 vector and creates a N2xN1 matrix img=img'; %creates a N1xN2 matrix by transposing the image. % Change image for manipulation dbx=[]; % A matrix for i=1:M temp=double(S(:,i)); dbx=[dbx temp]; end %Covariance matrix C=A'A, L=AA' A=dbx'; L=A*A'; % vv are the eigenvector for L % dd are the eigenvalue for both L=dbx'*dbx and C=dbx*dbx'; [vv dd]=eig(L); % Sort and eliminate those whose eigenvalue is zero v=[]; d=[]; for i=1:size(vv,2) if(dd(i,i)>1e-4) v=[v vv(:,i)]; d=[d dd(i,i)]; end end %sort, will return an ascending sequence [B index]=sort(d); ind=zeros(size(index)); dtemp=zeros(size(index)); vtemp=zeros(size(v)); len=length(index); for i=1:len dtemp(i)=B(len+1-i); ind(i)=len+1-index(i); vtemp(:,ind(i))=v(:,i); end d=dtemp; v=vtemp; %Normalization of eigenvectors for i=1:size(v,2) %access each column kk=v(:,i); temp=sqrt(sum(kk.^2)); v(:,i)=v(:,i)./temp; end %Eigenvectors of C matrix u=[]; for i=1:size(v,2) temp=sqrt(d(i)); u=[u (dbx*v(:,i))./temp]; end %Normalization of eigenvectors for i=1:size(u,2) kk=u(:,i); temp=sqrt(sum(kk.^2)); u(:,i)=u(:,i)./temp; end % show eigenfaces; for i=1:size(u,2) img=reshape(u(:,i),icol,irow); img=img'; img=histeq(img,255); end % Find the weight of each face in the training set. omega = []; for h=1:size(dbx,2) WW=[]; for i=1:size(u,2) t = u(:,i)'; WeightOfImage = dot(t,dbx(:,h)'); WW = [WW; WeightOfImage]; end omega = [omega WW]; end % Acquire new image % Note: the input image must have a bmp or jpg extension. % It should have the same size as the ones in your training set. % It should be placed on your desktop ed_min=[]; srcFiles = dir('G:\newdatabase\*.jpg'); % the folder in which ur images exists for b = 1 : length(srcFiles) filename = strcat('G:\newdatabase\',srcFiles(b).name); Imgdata = imread(filename); InputImage=Imgdata; InImage=reshape(permute((double(InputImage)),[2,1,3]),[irow*icol,1]); temp=InImage; me=mean(temp); st=std(temp); temp=(temp-me)*ustd/st+um; NormImage = temp; Difference = temp-m; p = []; aa=size(u,2); for i = 1:aa pare = dot(NormImage,u(:,i)); p = [p; pare]; end InImWeight = []; for i=1:size(u,2) t = u(:,i)'; WeightOfInputImage = dot(t,Difference'); InImWeight = [InImWeight; WeightOfInputImage]; end noe=numel(InImWeight); % Find Euclidean distance e=[]; for i=1:size(omega,2) q = omega(:,i); DiffWeight = InImWeight-q; mag = norm(DiffWeight); e = [e mag]; end ed_min=[ed_min MinimumValue]; theta=6.0e+03; %disp(e) z(b,:)=InImWeight; end IDX = kmeans(z,5); clustercount=accumarray(IDX, ones(size(IDX))); disp(clustercount); Running time for 50 images:Elapsed time is 103.947573 seconds. QUESTIONS: 1.It is working fine for M=50(i.e Training set contains 50 images) but not for M=1200(i.e Training set contains 1200 images).It is not showing any error.There is no output.I waited for 10 min still there is no output. I think it is going infinite loop.What is the problem?Where i was wrong?

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Need help with testdisk output

- by dan

I had (note the past tense) an ubuntu 12.04 system with separate partitions for the base and /home directories. It started acting wonky, so I decided to do a reinstall with 12.10, intending just to do a reinstall to the base partition. After several seconds, I realize that the installer was repartitioning the drive and reinstalling, so I pulled the power cord. I'm now trying to recover as much as I can with testdisk, but it seems that testdisk is finding 100 unique partitions when I run it - they mostly tend to be HFS+ or solaris /home (which I think is just an ext4; I've never had solaris on the machine). I've pasted an abbreviated version of the testdisk output below (first ~100 lines, and then ~100 lines from the middle of the output). Is there a way to combine or recreate the partitions and then data recovery, or some other way maximize what I can recover (ideally as much of the file system as possible)? I really only care about what was in the /home directory - I'd rather not use photorec since I don't have another 2 TB HD lying around to recover to. Thanks, Dan Mon Dec 10 06:03:00 2012 Command line: TestDisk TestDisk 6.13, Data Recovery Utility, November 2011 Christophe GRENIER <[email protected]> http://www.cgsecurity.org OS: Linux, kernel 3.2.34-std312-amd64 (#2 SMP Sat Nov 17 08:06:32 UTC 2012) x86_64 Compiler: GCC 4.4 Compilation date: 2012-11-27T22:44:52 ext2fs lib: 1.42.6, ntfs lib: libntfs-3g, reiserfs lib: 0.3.1-rc8, ewf lib: none /dev/sda: LBA, HPA, LBA48, DCO support /dev/sda: size 3907029168 sectors /dev/sda: user_max 3907029168 sectors /dev/sda: native_max 3907029168 sectors Warning: can't get size for Disk /dev/mapper/control - 0 B - CHS 1 1 1, sector size=512 /dev/sr0 is not an ATA disk Hard disk list Disk /dev/sda - 2000 GB / 1863 GiB - CHS 243201 255 63, sector size=512 - WDC WD20EARS-00J2GB0, S/N:WD-WCAYY0075071, FW:80.00A80 Disk /dev/sdb - 1013 MB / 967 MiB - CHS 1014 32 61, sector size=512 - Generic Flash Disk, FW:8.07 Disk /dev/sr0 - 367 MB / 350 MiB - CHS 179470 1 1 (RO), sector size=2048 - PLDS DVD+/-RW DH-16AAS, FW:JD12 Partition table type (auto): Intel Disk /dev/sda - 2000 GB / 1863 GiB - WDC WD20EARS-00J2GB0 Partition table type: EFI GPT Analyse Disk /dev/sda - 2000 GB / 1863 GiB - CHS 243201 255 63 Current partition structure: Bad GPT partition, invalid signature. search_part() Disk /dev/sda - 2000 GB / 1863 GiB - CHS 243201 255 63 recover_EXT2: s_block_group_nr=0/14880, s_mnt_count=5/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192 recover_EXT2: s_blocksize=4096 recover_EXT2: s_blocks_count 487593984 recover_EXT2: part_size 3900751872 MS Data 2048 3900753919 3900751872 EXT4 Large file Sparse superblock, 1997 GB / 1860 GiB Linux Swap 3900755968 3907028975 6273008 SWAP2 version 1, 3211 MB / 3062 MiB Results P MS Data 2048 3900753919 3900751872 EXT4 Large file Sparse superblock, 1997 GB / 1860 GiB P Linux Swap 3900755968 3907028975 6273008 SWAP2 version 1, 3211 MB / 3062 MiB interface_write() 1 P MS Data 2048 3900753919 3900751872 2 P Linux Swap 3900755968 3907028975 6273008 search_part() Disk /dev/sda - 2000 GB / 1863 GiB - CHS 243201 255 63 recover_EXT2: s_block_group_nr=0/14880, s_mnt_count=5/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192 recover_EXT2: s_blocksize=4096 recover_EXT2: s_blocks_count 487593984 recover_EXT2: part_size 3900751872 MS Data 2048 3900753919 3900751872 EXT4 Large file Sparse superblock, 1997 GB / 1860 GiB block_group_nr 1 recover_EXT2: "e2fsck -b 32768 -B 4096 device" may be needed recover_EXT2: s_block_group_nr=1/14880, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192 recover_EXT2: s_blocksize=4096 recover_EXT2: s_blocks_count 487593984 recover_EXT2: part_size 3900751872 MS Data 2046 3900753917 3900751872 EXT4 Large file Sparse superblock Backup superblock, 1997 GB / 1860 GiB block_group_nr 1 recover_EXT2: "e2fsck -b 32768 -B 4096 device" may be needed recover_EXT2: s_block_group_nr=1/14880, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192 recover_EXT2: s_blocksize=4096 recover_EXT2: s_blocks_count 487593984 recover_EXT2: part_size 3900751872 MS Data 2048 3900753919 3900751872 EXT4 Large file Sparse superblock Backup superblock, 1997 GB / 1860 GiB block_group_nr 1 recover_EXT2: "e2fsck -b 32768 -B 4096 device" may be needed recover_EXT2: s_block_group_nr=1/14584, s_mnt_count=0/27, s_blocks_per_group=32768, s_inodes_per_group=8192 recover_EXT2: s_blocksize=4096 recover_EXT2: s_blocks_count 477915164 recover_EXT2: part_size 3823321312 MS Data 4094 3823325405 3823321312 EXT4 Large file Sparse superblock Backup superblock, 1957 GB / 1823 GiB block_group_nr 1 ....snip...... MS Data 2046 3900753917 3900751872 EXT4 Large file Sparse superblock Backup superblock, 1997 GB / 1860 GiB MS Data 2048 3900753919 3900751872 EXT4 Large file Sparse superblock, 1997 GB / 1860 GiB MS Data 4094 3823325405 3823321312 EXT4 Large file Sparse superblock Backup superblock, 1957 GB / 1823 GiB MS Data 4096 3823325407 3823321312 EXT4 Large file Sparse superblock Backup superblock, 1957 GB / 1823 GiB MS Data 7028840 7033383 4544 FAT12, 2326 KB / 2272 KiB Mac HFS 67856948 67862179 5232 HFS+ found using backup sector!, 2678 KB / 2616 KiB Mac HFS 67862176 67867407 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 67862244 67867475 5232 HFS+ found using backup sector!, 2678 KB / 2616 KiB Mac HFS 67867404 67872635 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 67867472 67872703 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 67872700 67877931 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 67937834 67948067 10234 [EasyInstall_OSX] HFS found using backup sector!, 5239 KB / 5117 KiB Mac HFS 67938012 67948155 10144 HFS+ found using backup sector!, 5193 KB / 5072 KiB Mac HFS 67948064 67958297 10234 [EasyInstall_OSX] HFS, 5239 KB / 5117 KiB Mac HFS 67948070 67958303 10234 [EasyInstall_OSX] HFS found using backup sector!, 5239 KB / 5117 KiB Mac HFS 67948152 67958295 10144 HFS+, 5193 KB / 5072 KiB Mac HFS 67958292 67968435 10144 HFS+, 5193 KB / 5072 KiB Mac HFS 67958300 67968533 10234 [EasyInstall_OSX] HFS, 5239 KB / 5117 KiB Mac HFS 67992596 67997827 5232 HFS+ found using backup sector!, 2678 KB / 2616 KiB Mac HFS 67997824 68003055 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 67997892 68003123 5232 HFS+ found using backup sector!, 2678 KB / 2616 KiB Mac HFS 68003052 68008283 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 68003120 68008351 5232 HFS+, 2678 KB / 2616 KiB Mac HFS 68008348 68013579 5232 HFS+, 2678 KB / 2616 KiB Solaris /home 84429840 123499141 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84429952 123499253 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84493136 123562437 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84493248 123562549 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84566088 123635389 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84566200 123635501 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84571232 123640533 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84571344 123640645 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84659952 123729253 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84660064 123729365 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84690504 123759805 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84690616 123759917 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84700424 123769725 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84700536 123769837 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84797720 123867021 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84797832 123867133 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84812544 123881845 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84812656 123881957 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84824552 123893853 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84824664 123893965 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84847528 123916829 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84847640 123916941 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84886840 123956141 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84886952 123956253 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84945488 124014789 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84945600 124014901 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84957992 124027293 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84958104 124027405 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84962240 124031541 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84962352 124031653 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84977168 124046469 39069302 UFS1, 20 GB / 18 GiB Solaris /home 84977280 124046581 39069302 UFS1, 20 GB / 18 GiB MS Data 174395467 178483851 4088385 ..... snip (it keeps going on for quite a while)

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Trying to install Team viewer on Ubuntu 12.04

- by Teknikk

I recently got Ubuntu installed on my server, I wanted to install TeamViewer so i could easy manage the virtual machines, However, I get errors when installing it from App store?, And I also get errors, but more detailed on the terminal. Error output: tek@tek-G53SW:~/Download$ sudo dpkg -i ipts teamviewer_linux_x64.deb dpkg: error processing ipts (--install): cannot access archive: No such file or directory (Reading database ... 142115 files and directories currently installed.) Preparing to replace teamviewer7 7.0.9360 (using teamviewer_linux_x64.deb) ... Unpacking replacement teamviewer7 ... dpkg: dependency problems prevent configuration of teamviewer7: teamviewer7 depends on libc6-i386 (>= 2.7); however: Package libc6-i386 is not installed. teamviewer7 depends on lib32asound2; however: Package lib32asound2 is not installed. teamviewer7 depends on lib32z1; however: Package lib32z1 is not installed. teamviewer7 depends on ia32-libs; however: Package ia32-libs is not installed. dpkg: error processing teamviewer7 (--install): dependency problems - leaving unconfigured Errors were encountered while processing: ipts teamviewer7 I tried to install it manually, but with no luck, I heard some others has this problems. I am running Ubuntu 12.04 x64. Error @ sudo apt-get install libc6-i386 lib32asound2 lib32z1 ia32-libs : tek@tek-G53SW:~/Download$ sudo apt-get install libc6-i386 lib32asound2 lib32z1 ia32-libs Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: ia32-libs : Depends: ia32-libs-multiarch E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). tek@tek-G53SW:~/Download$ More errors tek@tek-G53SW:~/Download$ sudo apt-get -f install [sudo] password for tek: Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages will be REMOVED: teamviewer7 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 81.9 MB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 142441 files and directories currently installed.) Removing teamviewer7 ... tek@tek-G53SW:~/Download$ sudo apt-get install libc6-i386 lib32asound2 lib32z1 ia32-libs Reading package lists... Done Building dependency tree Reading state information... Done lib32z1 is already the newest version. libc6-i386 is already the newest version. lib32asound2 is already the newest version. Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: ia32-libs : Depends: ia32-libs-multiarch E: Unable to correct problems, you have held broken packages. tek@tek-G53SW:~/Download$ sudo apt-get install ia32-libs-multiarch Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: ia32-libs-multiarch:i386 : Depends: gstreamer0.10-plugins-good:i386 but it is not going to be installed Depends: gtk2-engines:i386 but it is not going to be installed Depends: gtk2-engines-murrine:i386 but it is not going to be installed Depends: gtk2-engines-pixbuf:i386 but it is not going to be installed Depends: gtk2-engines-oxygen:i386 but it is not going to be installed Depends: ibus-gtk:i386 but it is not going to be installed Depends: libcanberra-gtk-module:i386 but it is not going to be installed Depends: libcups2:i386 but it is not going to be installed Depends: libcupsimage2:i386 but it is not going to be installed Depends: libfontconfig1:i386 but it is not going to be installed Depends: libgail-common:i386 but it is not going to be installed Depends: libgphoto2-2:i386 but it is not going to be installed Depends: libgtk2.0-0:i386 but it is not going to be installed Depends: libnss3:i386 but it is not going to be installed Depends: libqt4-opengl:i386 but it is not going to be installed Depends: libqt4-qt3support:i386 but it is not going to be installed Depends: libqt4-scripttools:i386 but it is not going to be installed Depends: libqt4-svg:i386 but it is not going to be installed Depends: libqtgui4:i386 but it is not going to be installed Depends: libqtwebkit4:i386 but it is not going to be installed Depends: librsvg2-common:i386 but it is not going to be installed Depends: libsane:i386 but it is not going to be installed E: Unable to correct problems, you have held broken packages. tek@tek-G53SW:~/Download$

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Premature-Optimization and Performance Anxiety

- by James Michael Hare

While writing my post analyzing the new .NET 4 ConcurrentDictionary class (here), I fell into one of the classic blunders that I myself always love to warn about. After analyzing the differences of time between a Dictionary with locking versus the new ConcurrentDictionary class, I noted that the ConcurrentDictionary was faster with read-heavy multi-threaded operations. Then, I made the classic blunder of thinking that because the original Dictionary with locking was faster for those write-heavy uses, it was the best choice for those types of tasks. In short, I fell into the premature-optimization anti-pattern. Basically, the premature-optimization anti-pattern is when a developer is coding very early for a perceived (whether rightly-or-wrongly) performance gain and sacrificing good design and maintainability in the process. At best, the performance gains are usually negligible and at worst, can either negatively impact performance, or can degrade maintainability so much that time to market suffers or the code becomes very fragile due to the complexity. Keep in mind the distinction above. I'm not talking about valid performance decisions. There are decisions one should make when designing and writing an application that are valid performance decisions. Examples of this are knowing the best data structures for a given situation (Dictionary versus List, for example) and choosing performance algorithms (linear search vs. binary search). But these in my mind are macro optimizations. The error is not in deciding to use a better data structure or algorithm, the anti-pattern as stated above is when you attempt to over-optimize early on in such a way that it sacrifices maintainability. In my case, I was actually considering trading the safety and maintainability gains of the ConcurrentDictionary (no locking required) for a slight performance gain by using the Dictionary with locking. This would have been a mistake as I would be trading maintainability (ConcurrentDictionary requires no locking which helps readability) and safety (ConcurrentDictionary is safe for iteration even while being modified and you don't risk the developer locking incorrectly) -- and I fell for it even when I knew to watch out for it. I think in my case, and it may be true for others as well, a large part of it was due to the time I was trained as a developer. I began college in in the 90s when C and C++ was king and hardware speed and memory were still relatively priceless commodities and not to be squandered. In those days, using a long instead of a short could waste precious resources, and as such, we were taught to try to minimize space and favor performance. This is why in many cases such early code-bases were very hard to maintain. I don't know how many times I heard back then to avoid too many function calls because of the overhead -- and in fact just last year I heard a new hire in the company where I work declare that she didn't want to refactor a long method because of function call overhead. Now back then, that may have been a valid concern, but with today's modern hardware even if you're calling a trivial method in an extremely tight loop (which chances are the JIT compiler would optimize anyway) the results of removing method calls to speed up performance are negligible for the great majority of applications. Now, obviously, there are those coding applications where speed is absolutely king (for example drivers, computer games, operating systems) where such sacrifices may be made. But I would strongly advice against such optimization because of it's cost. Many folks that are performing an optimization think it's always a win-win. That they're simply adding speed to the application, what could possibly be wrong with that? What they don't realize is the cost of their choice. For every piece of straight-forward code that you obfuscate with performance enhancements, you risk the introduction of bugs in the long term technical debt of the application. It will become so fragile over time that maintenance will become a nightmare. I've seen such applications in places I have worked. There are times I've seen applications where the designer was so obsessed with performance that they even designed their own memory management system for their application to try to squeeze out every ounce of performance. Unfortunately, the application stability often suffers as a result and it is very difficult for anyone other than the original designer to maintain. I've even seen this recently where I heard a C++ developer bemoaning that in VS2010 the iterators are about twice as slow as they used to be because Microsoft added range checking (probably as part of the 0x standard implementation). To me this was almost a joke. Twice as slow sounds bad, but it almost never as bad as you think -- especially if you're gaining safety. The only time twice is really that much slower is when once was too slow to begin with. Think about it. 2 minutes is slow as a response time because 1 minute is slow. But if an iterator takes 1 microsecond to move one position and a new, safer iterator takes 2 microseconds, this is trivial! The only way you'd ever really notice this would be in iterating a collection just for the sake of iterating (i.e. no other operations). To my mind, the added safety makes the extra time worth it. Always favor safety and maintainability when you can. I know it can be a hard habit to break, especially if you started out your career early or in a language such as C where they are very performance conscious. But in reality, these type of micro-optimizations only end up hurting you in the long run. Remember the two laws of optimization. I'm not sure where I first heard these, but they are so true: For beginners: Do not optimize. For experts: Do not optimize yet. This is so true. If you're a beginner, resist the urge to optimize at all costs. And if you are an expert, delay that decision. As long as you have chosen the right data structures and algorithms for your task, your performance will probably be more than sufficient. Chances are it will be network, database, or disk hits that will be your slow-down, not your code. As they say, 98% of your code's bottleneck is in 2% of your code so premature-optimization may add maintenance and safety debt that won't have any measurable impact. Instead, code for maintainability and safety, and then, and only then, when you find a true bottleneck, then you should go back and optimize further.

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