Search Results

Search found 6945 results on 278 pages for 'azure use cases'.

Page 263/278 | < Previous Page | 259 260 261 262 263 264 265 266 267 268 269 270 | Next Page >

When working with gems in Rails, what does 'cannot remove Object::ClassMethods' stem from?

- by Matt

Frequently I have run into a problem when installing gems that provides a problem like: Does anyone know what this stems from? I've seen in it several different cases, yet still haven't learned what exactly is causing it. $ sudo rake gems:install --trace (in /u/app/releases/20100213003957) ** Invoke gems:install (first_time) ** Invoke gems:base (first_time) ** Execute gems:base ** Invoke environment (first_time) ** Execute environment rake aborted! cannot remove Object::ClassMethods /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:603:in `remove_const' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:603:in `remove_constant' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:603:in `instance_eval' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:603:in `remove_constant' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:549:in `new_constants_in' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:549:in `each' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:549:in `new_constants_in' /u/app/releases/20100213003957/vendor/rails/activesupport/lib/active_support/dependencies.rb:156:in `require' /u/app/releases/20100213003957/vendor/rails/railties/lib/tasks/misc.rake:4 /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:617:in `call' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:617:in `execute' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:612:in `each' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:612:in `execute' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:578:in `invoke_with_call_chain' /usr/lib64/ruby/1.8/monitor.rb:242:in `synchronize' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:571:in `invoke_with_call_chain' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:564:in `invoke' /u/app/releases/20100213003957/vendor/rails/railties/lib/tasks/gems.rake:17 /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:617:in `call' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:617:in `execute' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:612:in `each' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:612:in `execute' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:578:in `invoke_with_call_chain' /usr/lib64/ruby/1.8/monitor.rb:242:in `synchronize' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:571:in `invoke_with_call_chain' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:588:in `invoke_prerequisites' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:585:in `each' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:585:in `invoke_prerequisites' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:577:in `invoke_with_call_chain' /usr/lib64/ruby/1.8/monitor.rb:242:in `synchronize' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:571:in `invoke_with_call_chain' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:564:in `invoke' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2027:in `invoke_task' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2005:in `top_level' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2005:in `each' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2005:in `top_level' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2044:in `standard_exception_handling' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:1999:in `top_level' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:1977:in `run' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:2044:in `standard_exception_handling' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/lib/rake.rb:1974:in `run' /usr/lib64/ruby/gems/1.8/gems/rake-0.8.4/bin/rake:31 /usr/bin/rake:19:in `load' /usr/bin/rake:19

Read the article
Android 1.5 - 2.1 Search Activity affects Parent Lifecycle

- by pacoder

Behavior seems consistent in Android 1.5 to 2.1 Short version is this, it appears that when my (android search facility) search activity is fired from the android QSR due to either a suggestion or search, UNLESS my search activity in turn fires off a VISIBLE activity that is not the parent of the search, the search parents life cycle changes. It will NOT fire onDestroy until I launch a visible activity from it. If I do, onDestroy will fire fine. I need a way to get around this behavior... The long version: We have implemented a SearchSuggestion provider and a Search activity in our application. The one thing about it that is very odd is that if the SearchManager passes control to our custom Search activity, AND that activity does not create a visible Activity the Activity which parented the search does not destroy (onDestroy doesn't run) and it will not until we call a visible Activity from the parent activity. As long as our Search Activity fires off another Activity that gets focus the parent activity will fire onDestroy when I back out of it. The trick is that Activity must have a visual component. I tried to fake it out with a 'pass through' Activity so that my Search Activity could fire off another Intent and bail out but that didn't work either. I have tried setting our SearchActivity to launch singleTop and I also tried setting its noHistory attribute to true, tried setResult(RESULT_OK) in SearchACtivity prior to finish, bunch of other things, nothing is working. This is the chunk of code in our Search Activity onCreate. Couple of notes about it: If Intent is Action_Search (user typed in their own search and didn't pick a suggestion), we display a list of results as our Search Activity is a ListActivity. In this case when the item is picked, the Search Activity closes and our parent Activity does fire onDestroy() when we back out. If Intent is Action_View (user picked a suggestion) when type is "action" we fire off an Intent that creates a new visible Activity. In this case same thing, when we leave that new activity and return to the parent activity, the back key does cause the parent activity to fire onDestroy when leaving. If Intent is Action_View (user picked a suggestion) when type is "pitem" is where the problem lies. It works fine (the method call focuses an item on the parent activity), but when the back button is hit on the parent activity onDestroy is NOT called. IF after this executes I pick an option in the parent activity that fires off another activity and return to the parent then back out it will fire onDestroy() in the parent activity. Note that the "action" intent ends up running the exact same method call as "pitem", it just bring up a new visual Activity first. Also I can take out the method call from "pitem" and just finish() and the behavior is the same, the parent activity doesn't fire onDestroy() when backed out of. if (Intent.ACTION_SEARCH.equals(queryAction)) { this.setContentView(_layoutId); String searchKeywords = queryIntent.getStringExtra(SearchManager.QUERY); init(searchKeywords); } else if(Intent.ACTION_VIEW.equals(queryAction)){ Bundle bundle = queryIntent.getExtras(); String key = queryIntent.getDataString(); String userQuery = bundle.getString(SearchManager.USER_QUERY); String[] keyValues = key.split("-"); if(keyValues.length == 2) { String type = keyValues[0]; String value = keyValues[1]; if(type.equals("action")) { Intent intent = new Intent(this, EventInfoActivity.class); Long longKey = Long.parseLong(value); intent.putExtra("vo_id", longKey); startActivity(intent); finish(); } else if(type.equals("pitem")) { Integer id = Integer.parseInt(value); _application._servicesManager._mapHandlerSelector.selectInfoItem(id); finish(); } } } It just seems like something is being held onto and I can't figure out what it is, in all cases the Search Activity fires onDestroy() when finish() is called so it is definitely going away. If anyone has any suggestions I'd be most appreciative. Thanks, Sean Overby

Read the article
Trying to link http://www.example.com to my shopping cart on https://secure.example.com

- by Pickledegg

Heres my saga - I'm trying to link http://www.example.com to my shopping cart on https://secure.example.com, but it doesnt seem to be linking correctly. Heres my code:  <script type="text/javascript"> var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); </script> <script type="text/javascript"> try { var pageTracker = _gat._getTracker("UA-125xxxxx-1"); //start cart link pageTracker._setDomainName(".example.com"); pageTracker._setAllowHash(false); //end cart link pageTracker._trackPageview(); } catch(err) {}</script>  Notice the two lines: pageTracker._setDomainName(".example.com"); pageTracker._setAllowHash(false); I added the first line so I could share the cookies between site and cart, and added the setAllowHash to make sure it used the utm values from the cookie, and didnt 'recreate' them when I entered https://secure.example.com. Using firecookie, it does indeed share the same cookie between site and cart, and the cookies domain is 'example.com'. I'm pretty sure though that if it was working right, all my utmz, utma values etc should be copied over and remain the same, but they're changing. I've copied all the params that are being sent to google analytics and pasted then below. It shows what is happening from my homepage, to my product page, then into my cart all the way to the page before ordering. ( I can't practically test the final page myself without buying something, so I'll post the code from our confirmation page later if needed.) Here goes: =============================================================== HOMEPAGE - http://www.example.com ---------------------------------------------------------------------------------------- utmac UA-125xxxxx-1 utmcc __utma=1.1920057171.1269446996.1269446996.1269446996.1;+__utmz=1.1269446996.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); utmcs UTF-8 utmdt GSM Cell Phone Rental from example utmfl 10.0 r45 utmhid 69978133 utmhn www.example.com utmje 1 utmn 1806413990 utmp / utmr - utmsc 24-bit utmsr 1280x800 utmul en-gb utmwv 4.6.5 PRODUCT PAGE - http://www.example.com/products/international-cell-phone-purchase/ ---------------------------------------------------------------- utmac UA-125xxxxx-1 utmcc __utma=1.1920057171.1269446996.1269446996.1269446996.1;+__utmz=1.1269446996.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); utmcs UTF-8 utmdt example | International Cell Phones utmfl 10.0 r45 utmhid 276151647 utmhn www.example.com utmje 1 utmn 155808433 utmp /products/international-cell-phone-purchase/ utmr 0 utmsc 24-bit utmsr 1280x800 utmul en-gb utmwv 4.6.5 CART STAGE 1 - https://secure.example.com/checkout/viewbasket.php ------------------------------------------------ utmac UA-125xxxxx-1 utmcc __utma=60286578.994269564.1269447144.1269447144.1269447144.1;+__utmz=60286578.1269447144.1.1.utmcsr=example.com|utmccn=(referral)|utmcmd=referral|utmcct=/products/international-cell-phone-purchase/; utmcn 1 utmcs UTF-8 utmdt Your Cart utmfl 10.0 r45 utmhid 1802074903 utmhn secure.example.com utmje 1 utmn 1621444199 utmp 1-reviewcart utmr http://www.example.com/products/international-cell-phone-purchase/ utmsc 24-bit utmsr 1280x800 utmul en-gb utmwv 4.6.5 CART STAGE 2 - https://secure.example.com/checkout/docheckout.php ------------------------------------------------ utmac UA-125xxxxx-1 utmcc __utma=60286578.994269564.1269447144.1269447144.1269447144.1;+__utmz=60286578.1269447144.1.1.utmcsr=example.com|utmccn=(referral)|utmcmd=referral|utmcct=/products/international-cell-phone-purchase/; utmcs UTF-8 utmdt Checkout utmfl 10.0 r45 utmhid 871670520 utmhn secure.example.com utmje 1 utmn 1153927228 utmp 2-checkout utmr 0 utmsc 24-bit utmsr 1280x800 utmul en-gb utmwv 4.6.5 CART STAGE 3 - https://secure.example.com/checkout/doreview.php ---------------------------------------------- utmac UA-125xxxxx-1 utmcc __utma=60286578.994269564.1269447144.1269447144.1269447144.1;+__utmz=60286578.1269447144.1.1.utmcsr=example.com|utmccn=(referral)|utmcmd=referral|utmcct=/products/international-cell-phone-purchase/; utmcs UTF-8 utmdt Checkout utmfl 10.0 r45 utmhid 1731598159 utmhn secure.example.com utmje 1 utmn 1442257710 utmp 3-checkoutreview utmr 0 utmsc 24-bit utmsr 1280x800 utmul en-gb utmwv 4.6.5 =============================================================== As you can see, the utma values are not being preserved, so it looks like a config issue. I've studied the help does but none of the cases seem to fit mine. I hope someone can offer help on this, its been an ongoing problem of mine for a while, and would be good to finally get rock-solid reliable analytics set up.

Read the article
non-static variable cannot be referenced from a static context (java)

- by Greg

I ask that you ignore all logic.. i was taught poorly at first and so i still dont understand everything about static crap and its killing me. My error is with every single variable that i declare then try to use later inside my methods... i get the non-static variable cannot~~ error I can simply put all the rough coding of my methods inside my cases, and it works but then i cannot use recursion... What i really need is someone to help on the syntax and point me on the right direction of how to have my methods recognize my variables at the top... like compareCount etc thanks public class MyProgram7 { public static void main (String[]args) throws IOException{ Scanner scan = new Scanner(System.in); int compareCount = 0; int low = 0; int high = 0; int mid = 0; int key = 0; Scanner temp; int[]list; String menu, outputString; int option = 1; boolean found = false; // Prompt the user to select an option menu = "\n\t1 Reads file" + "\n\t2 Finds a specific number in the list" + "\n\t3 Prints how many comparisons were needed" + "\n\t0 Quit\n\n\n"; System.out.println(menu); System.out.print("\tEnter your selection: "); option = scan.nextInt(); // Keep reading data until the user enters 0 while (option != 0) { switch (option) { case 1: readFile(); break; case 2: findKey(list,low,high,key); break; case 3: printCount(); break; default: outputString = "\nInvalid Selection\n"; System.out.println(outputString); break; }//end of switch System.out.println(menu); System.out.print("\tEnter your selection: "); option = scan.nextInt(); }//end of while }//end of main public static void readFile() { int i = 0; temp = new Scanner(new File("CS1302_Data7_2010.txt")); while(temp.hasNext()) { list[i]= temp.nextInt(); i++; }//end of while temp.close(); System.out.println("File Found..."); }//end of readFile() public static void findKey() { while(found!=true) { while(key < 100 || key > 999) { System.out.println("Please enter the number you would like to search for? ie 350: "); key = scan.nextInt(); }//end of inside while //base if (low <= high) { mid = ((low+high)/2); if (key == list[mid]) { found = true; compareCount++; }//end of inside if }//end of outside if else if (key < list[mid]) { compareCount++; high = mid-1; findKey(list,low,high,key); }//end of else if else { compareCount++; low = mid+1; findKey(list,low,high,key); }//end of else }//end of outside while }//end of findKey() public static void printCount() { System.out.println("Total number of comparisons is: " + compareCount); }//end of printCount }//end of class

Read the article
Apache mod_rewrite driving me mad

- by WishCow

The scenario I have a webhost that is shared among multiple sites, the directory layout looks like this: siteA/ - css/ - js/ - index.php siteB/ - css/ - js/ - index.php siteC/ . . . The DocumentRoot is at the top level, so, to access siteA, you type http://webhost/siteA in your browser, to access siteB, you type http://webhost/siteB, and so on. Now I have to deploy my own site, which was designed with having 3 VirtualHosts in mind, so my structure looks like this: siteD/ - sites/sitename.com/ - log/ - htdocs/ - index.php - sites/static.sitename.com - log/ - htdocs/ - css - js - sites/admin.sitename.com - log/ - htdocs/ - index.php As you see, the problem is that my index.php files are not at the top level directory, unlike the already existing sites on the webhost. Each VirtualHost should point to the corresponding htdocs/ folder: http://siteD.com -> siteD/sites/sitename.com/htdocs http://static.siteD.com -> siteD/sites/static.sitename.com/htdocs http://admin.siteD.com -> siteD/sites/admin.sitename.com/htdocs The problem I cannot have VirtualHosts on this host, so I have to emulate it somehow, possibly with mod_rewrite. The idea Have some predefined parts in all of the links on the site, that I can identify, and route accordingly to the correct file, with mod_rewrite. Examples: http://webhost/siteD/static/js/something.js -> siteD/sites/static.sitename.com/htdocs/js/something.js http://webhost/siteD/static/css/something.css -> siteD/sites/static.sitename.com/htdocs/css/something.css http://webhost/siteD/admin/something -> siteD/sites/admin.sitename.com/htdocs/index.php http://webhost/siteD/admin/sub/something -> siteD/sites/admin.sitename.com/htdocs/index.php http://webhost/siteD/something -> siteD/sites/sitename.com/htdocs/index.php http://webhost/siteD/sub/something -> siteD/sites/sitename.com/htdocs/index.php Anything that starts with http://url/sitename/admin/(.*) will get rewritten, to point to siteD/sites/admin.sitename.com/htdocs/index.php Anything that starts with http://url/sitename/static/(.*) will get rewritten, to point to siteD/sites/static.sitename.com/htdocs/$1 Anything that starts with http://url/sitename/(.*) AND did not have a match already from above, will get rewritten to point to siteD/sites/sitename.com/htdocs/index.php The solution Here is the .htaccess file that I've come up with: RewriteEngine On RewriteBase / RewriteCond %{REQUEST_URI} ^/siteD/static/(.*)$ [NC] RewriteRule ^siteD/static/(.*)$ siteD/sites/static/htdocs/$1 [L] RewriteCond %{REQUEST_URI} ^/siteD/admin/(.*)$ [NC] RewriteRule ^siteD/(.*)$ siteD/sites/admin/htdocs/index.php [L,QSA] So far, so good. It's all working. Now to add the last rule: RewriteCond %{REQUEST_URI} ^/siteD/(.*)$ [NC] RewriteRule ^siteD/(.*)$ siteD/sites/public/htdocs/index.php [L,QSA] And it's broken. The last rule catches everything, even the ones that have static/ or admin/ in them. Why? Shouldn't the [L] flag stop the rewriting process in the first two cases? Why is the third case evaluated? Is there a better way of solving this? I'm not sticking to rewritemod, anything is fine as long as it does not need access to server-level config. I don't have access to RewriteLog, or anything like that. Please help :(

Read the article
How to pre-load all deployed assemblies for an AppDomain

- by Andras Zoltan

Given an App Domain, there are many different locations that Fusion (the .Net assembly loader) will probe for a given assembly. Obviously, we take this functionality for granted and, since the probing appears to be embedded within the .Net runtime (Assembly._nLoad internal method seems to be the entry-point when Reflect-Loading - and I assume that implicit loading is probably covered by the same underlying algorithm), as developers we don't seem to be able to gain access to those search paths. My problem is that I have a component that does a lot of dynamic type resolution, and which needs to be able to ensure that all user-deployed assemblies for a given AppDomain are pre-loaded before it starts its work. Yes, it slows down startup - but the benefits we get from this component totally outweight this. The basic loading algorithm I've already written is as follows. It deep-scans a set of folders for any .dll (.exes are being excluded at the moment), and uses Assembly.LoadFrom to load the dll if it's AssemblyName cannot be found in the set of assemblies already loaded into the AppDomain (this is implemented inefficiently, but it can be optimized later): void PreLoad(IEnumerable<string> paths) { foreach(path p in paths) { PreLoad(p); } } void PreLoad(string p) { //all try/catch blocks are elided for brevity string[] files = null; files = Directory.GetFiles(p, "*.dll", SearchOption.AllDirectories); AssemblyName a = null; foreach (var s in files) { a = AssemblyName.GetAssemblyName(s); if (!AppDomain.CurrentDomain.GetAssemblies().Any( assembly => AssemblyName.ReferenceMatchesDefinition( assembly.GetName(), a))) Assembly.LoadFrom(s); } } LoadFrom is used because I've found that using Load() can lead to duplicate assemblies being loaded by Fusion if, when it probes for it, it doesn't find one loaded from where it expects to find it. So, with this in place, all I now have to do is to get a list in precedence order (highest to lowest) of the search paths that Fusion is going to be using when it searches for an assembly. Then I can simply iterate through them. The GAC is irrelevant for this, and I'm not interested in any environment-driven fixed paths that Fusion might use - only those paths that can be gleaned from the AppDomain which contain assemblies expressly deployed for the app. My first iteration of this simply used AppDomain.BaseDirectory. This works for services, form apps and console apps. It doesn't work for an Asp.Net website, however, since there are at least two main locations - the AppDomain.DynamicDirectory (where Asp.Net places it's dynamically generated page classes and any assemblies that the Aspx page code references), and then the site's Bin folder - which can be discovered from the AppDomain.SetupInformation.PrivateBinPath property. So I now have working code for the most basic types of apps now (Sql Server-hosted AppDomains are another story since the filesystem is virtualised) - but I came across an interesting issue a couple of days ago where this code simply doesn't work: the nUnit test runner. This uses both Shadow Copying (so my algorithm would need to be discovering and loading them from the shadow-copy drop folder, not from the bin folder) and it sets up the PrivateBinPath as being relative to the base directory. And of course there are loads of other hosting scenarios that I probably haven't considered; but which must be valid because otherwise Fusion would choke on loading the assemblies. I want to stop feeling around and introducing hack upon hack to accommodate these new scenarios as they crop up - what I want is, given an AppDomain and its setup information, the ability to produce this list of Folders that I should scan in order to pick up all the DLLs that are going to be loaded; regardless of how the AppDomain is setup. If Fusion can see them as all the same, then so should my code. Of course, I might have to alter the algorithm if .Net changes its internals - that's just a cross I'll have to bear. Equally, I'm happy to consider SQL Server and any other similar environments as edge-cases that remain unsupported for now. Any ideas!?

Read the article
Where to Store the Protection Trial Info for Software Protection Purpose

- by Peter Lee

It might be duplicate with other questions, but I swear that I googled a lot and search at StackOverflow.com a lot, and I cannot find the answer to my question: In a C#.Net application, where to store the protection trial info, such as Expiration Date, Number of Used Times? I understand that, all kinds of Software Protection strategies can be cracked by a sophiscated hacker (because they can almost always get around the expiration checking step). But what I'm now going to do is just to protect it in a reasonable manner that a "common"/"advanced" user cannot screw it up. OK, in order to proof that I have googled and searched a lot at StackOverflow.com, I'm listing all the possible strategies I got: 1. Registry Entry First, some users might not have the access to even read the Registry table. Second, if we put the Protection Trial Info in a Registry Entry, the user can always find it out where it is by comparing the differences before and after the software installation. They can just simply change it. OK, you might say that we should encrypt the Protection Trial Info, yes we can do that. But what if the user just change their system date before installing? OK, you might say that we should also put a last-used date, if something is wrong, the last-used date could work as a protection guide. But what if the user just uninstall the software and delete all Registry Entries related to this software, and then reinstall the software? I have no idea on how to deal with this. Please help. A Plain File First, there are some places to put the plain file: 2.a) a simple XML file under software installation path 2.b) configuration file Again, the user can just uninstall the software and remove these plain file(s), and reinstall the software. - The Software Itself If we put the protection trial info (Expiration Date, we cannot put Number of Used Times) in the software itself, it is still susceptible to the cases I mentioned above. Furthermore, it's not even cool to do so. - A Trial Product-Key It works like a licensing process, that is, we put the Trial info into an RSA-signed string. However, it requires too many steps for a user to have a try of using the software (they might lose patience): 4.a) The user downloads the software; 4.b) The user sends an email to request a Trial Product-Key by providing user name (or email) or hardware info; 4.c) The server receives the request, RSA-signs it and send back to the user; 4.d) The user can now use it under the condition of (Expiration Date & Number of Used Times). Now, the server has a record of the user's username or hardware info, so the user will be rejected to request a second trial. Is it legal to collection hardware info? In a word, the user has to do one more extra step (request a Trial Product Key) just for having a try of using the software, which is not cool (thinking myself as a user). NOTE: This question is not about the Licensing, instead, it's about where to store the TRIAL info. After the trial expires, the user should ask for a license (CD-Key/Product-Key). I'm going to use RSA signature (bound to User Hardware)

Read the article
How to stop OpenGL from applying blending to certain content? (cocos2d/iPhone/OpenGL)

- by RexOnRoids

Supporting Info: I use cocos2d to draw a sprite (graph background) on the screen (z:-1). I then use cocos2d to draw lines/points (z:0) on top of the background -- and make some calls to OpenGL blending functions before the drawing to SMOOTH out the lines. Problem: The problem is that: aside from producing smooth lines/points, calling these OpenGL blending functions seems to degrade the underlying sprite (graph background). So there is a tradeoff: I can either have (Case 1) a nice background and choppy lines/points, or I can have (Case 2) nice smooth lines/points and a degraded background. But obviously I need both. The Code: I have included code of the draw() method of the CCLayer for both cases explained above. As you can see, the code producing the difference between Case 1 and Case 2 seems to be 1 or 2 lines involving OpenGL Blending. Case 1 -- MainScene.h (CCLayer): -(void)draw{ int lastPointX = 0; int lastPointY = 0; GLfloat colorMAX = 255.0f; GLfloat valR; GLfloat valG; GLfloat valB; if([self.myGraphManager ready]){ valR = (255.0f/colorMAX)*1.0f; valG = (255.0f/colorMAX)*1.0f; valB = (255.0f/colorMAX)*1.0f; NSEnumerator *enumerator = [[self.myGraphManager.currentCanvas graphPoints] objectEnumerator]; GraphPoint* object; while ((object = [enumerator nextObject])) { if(object.filled){ /*Commenting out the following two lines induces a problem of making it impossible to have smooth lines/points, but has merit in that it does not degrade the background sprite.*/ //glEnable (GL_BLEND); //glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE); glEnable (GL_LINE_SMOOTH); glLineWidth(1.5f); glColor4f(valR, valG, valB, 1.0); ccDrawLine(ccp(lastPointX, lastPointY), ccp(object.position.x, object.position.y)); lastPointX = object.position.x; lastPointY = object.position.y; glPointSize(3.0f); glEnable(GL_POINT_SMOOTH); glHint(GL_POINT_SMOOTH_HINT, GL_NICEST); ccDrawPoint(ccp(lastPointX, lastPointY)); } } } } Case 2 -- MainScene.h (CCLayer): -(void)draw{ int lastPointX = 0; int lastPointY = 0; GLfloat colorMAX = 255.0f; GLfloat valR; GLfloat valG; GLfloat valB; if([self.myGraphManager ready]){ valR = (255.0f/colorMAX)*1.0f; valG = (255.0f/colorMAX)*1.0f; valB = (255.0f/colorMAX)*1.0f; NSEnumerator *enumerator = [[self.myGraphManager.currentCanvas graphPoints] objectEnumerator]; GraphPoint* object; while ((object = [enumerator nextObject])) { if(object.filled){ /*Enabling the following two lines gives nice smooth lines/points, but has a problem in that it degrades the background sprite.*/ glEnable (GL_BLEND); glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE); glEnable (GL_LINE_SMOOTH); glLineWidth(1.5f); glColor4f(valR, valG, valB, 1.0); ccDrawLine(ccp(lastPointX, lastPointY), ccp(object.position.x, object.position.y)); lastPointX = object.position.x; lastPointY = object.position.y; glPointSize(3.0f); glEnable(GL_POINT_SMOOTH); glHint(GL_POINT_SMOOTH_HINT, GL_NICEST); ccDrawPoint(ccp(lastPointX, lastPointY)); } } } }

Read the article
Taking screenshots in Windows Vista, Windows 7, with transparent areas outside the app region

- by Steve Sheldon

Hey Folks, I am trying to take a screenshot of an application and I would like to make the parts of the rectangle that are not part of the applications region be transparent. So for instance on a standard windows application I would like to make the rounded corners transparent. I wrote a quick test application which works on on XP (or vista/windows 7 with aero turned off): protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); Graphics g = e.Graphics; // Just find a window to test with IntPtr hwnd = FindWindowByCaption(IntPtr.Zero, "Calculator"); WINDOWINFO info = new WINDOWINFO(); info.cbSize = (uint)Marshal.SizeOf(info); GetWindowInfo(hwnd, ref info); Rectangle r = Rectangle.FromLTRB(info.rcWindow.Left, info.rcWindow.Top, info.rcWindow.Right, info.rcWindow.Bottom); IntPtr hrgn = CreateRectRgn(info.rcWindow.Left, info.rcWindow.Top, info.rcWindow.Right, info.rcWindow.Bottom); GetWindowRgn(hwnd, hrgn); // fill a rectangle which would be where I would probably // write some mask color g.FillRectangle(Brushes.Red, r); // fill the region over the top, all I am trying to do here // is show the contrast between the applications region and // the rectangle that the region would be placed in Region region = Region.FromHrgn(hrgn); region.Translate(info.rcWindow.Left, info.rcWindow.Top); g.FillRegion(Brushes.Blue, region); } Quick side note: before commenting that this code is doing stuff it shouldn't (or should do, like dispose) in a paint function, I know, it's not going anywhere but this post and is designed purely as a way to quickly show the problem, and that it does... OK, back to the problem ;) When I run this test app on XP (or Vista/Windows 7 with Aero off), I get something like this, which is great because I can eek an xor mask out of this that can be used later with BitBlt. Here is the problem, on Vista or Windows 7 with Aero enabled, there isn't necessarily a region on the window, in fact in most cases there isn't. Can anybody help me figure out how to get the region of the application like this on these platforms. Here are some of the approaches I have already tried... 1. Using the PrintWindow function: This doesn't work because it gives back a screenshot taken of the window with Aero off and this window is a different shape from the window returned with Aero on 2 Using the Desktop Window Manager API to get a full size thumbnail: This didn't work because it draws directly to the screen and from what I can tell you can't get a screenshot directly out of this api. Yeah, I could open a window with a pink background, show the thumbnail, take a screenshot then hide this temporary window but thats a horrible user experience and a complete hack I would rather not have my name on. 3. Using Graphics.CopyFromScreen or some other pinvoke variant of this: This doesn't work because I can't assume that the window I need information from is at the top of the z-order on the screen. Right now, the best solution I can think of is to special case Aero on Windows 7 and Vista to manually rub out the corners by hard coding some graphics paths I paint out but this solution would suck since any application that performs custom skinning will break this. Can you think of another or better solution? If you are here, thanks for taking time to read this post, I appreciate any help or direction that you can offer!

Read the article
Web service using Data Dynamics ActiveReports occasionally slows down

- by Swoop

My company is running into a problem with a web service that is written in C#/ASP.Net. The service receives an identity key for data in SQL Server and a path to generate and save a PDF report for this data. In most cases, this web service returns results to the calling web pages very quickly, usually within a few seconds max. However, it seems to occasionally hit a significant slowdown. The web application calling the web service will generate a timeout error when this slowdown occurs. We have checked and the PDF does get created and saved to the server, so it looks like the web service eventually finishes executing. It seems to take about 1 to 2 minutes for processing to have completed. The PDF is generated using ActiveReports from Data Dynamics. Wwhen this problem occurs, making a small change to the web service's config file (ie, adding a blank space to a connection string line) seems to restart the web service and everything is perfectly ok for a period of time afterwards. Other web applications that are running on the same web server do not seem to experience this type of behavior, only this particular web service. I have added the code for the web service below. It is basic calls to 3rd party libraries. We are not able to recreate this problem in test. I am wondering what might be causing this issue? [WebMethod] public string Publish(int identity, string transactionType, string directory, string filename) { try { AdpConnection Conn = new AdpConnection(ConfigurationManager.AppSettings["myDBConnString"]); AdpCommand Cmd = new AdpCommand("storedproc_GetData", oConn); AdpParameter Param; Cmd.CommandType = CommandType.StoredProcedure; Param = Cmd.CreateParameter("@Identity", DbType.Int32); Param.Value = identity; Cmd.Parameters.Add(oParam); Conn.Open(); string aResponse = Cmd.ExecuteScalar().ToString(); Conn.Close(); if (transactionType == "typeA") { //Parse response DataSet dsResponse = ParseDataResponse(aResponse); //dsResponse.WriteXml(@ConfigurationManager.AppSettings["DocsDir"] + identity.ToString() + ".xml"); DataDynamics.ActiveReports.ActiveReport3 rpt = new DataDynamics.ActiveReports.ActiveReport3(); rpt.LoadLayout(@ConfigurationManager.AppSettings["myReportPath"] + "TypeA.rpx"); rpt.AddNamedItem("ReportPath", @ConfigurationManager.AppSettings["myReportPath"]); rpt.AddNamedItem("XMLSTRING", FormatXML(dsResponse.GetXml())); DataDynamics.ActiveReports.DataSources.XMLDataSource xmlds = new DataDynamics.ActiveReports.DataSources.XMLDataSource(); xmlds.FileURL = null; xmlds.RecordsetPattern = "//DataPatternA"; xmlds.LoadXML(FormatXML(dsResponse.GetXml())); if (!System.IO.Directory.Exists(@ConfigurationManager.AppSettings["DocsDir"] + directory + @"\")) { System.IO.Directory.CreateDirectory(@ConfigurationManager.AppSettings["DocsDir"] + directory + @"\"); } string sXML = FormatXML(dsResponse.GetXml()); StreamWriter sw = new StreamWriter(@ConfigurationManager.AppSettings["DocsDir"] + directory + @"\" + filename + ".xml", false); sw.Write(sXML); sw.Close(); rpt.DataSource = xmlds; rpt.Run(true); DataDynamics.ActiveReports.Export.Pdf.PdfExport xPdf = new DataDynamics.ActiveReports.Export.Pdf.PdfExport(); xPdf.Export(rpt.Document, @ConfigurationManager.AppSettings["DocsDir"] + directory + @"\" + filename + ".pdf"); } } catch(Exception ex) { return "Error: " + ex.ToString(); } return @ConfigurationManager.AppSettings["DocsDir"] + directory + @"\" + filename + ".pdf"; }

Read the article
Flushing a queue using AMQP, Rabbit, and Ruby

- by jeffshantz

I'm developing a system in Ruby that is going to make use of RabbitMQ to send messages to a queue as it does some work. I am using: Ruby 1.9.1 Stable RabbitMQ 1.7.2 AMQP gem v0.6.7 (http://github.com/tmm1/amqp) Most of the examples I have seen on this gem have their publish calls in an EM.add_periodic_timer block. This doesn't work for what I suspect is a vast majority of use cases, and certainly not for mine. I need to publish a message as I complete some work, so putting a publish statement in an add_periodic_timer block doesn't suffice. So, I'm trying to figure out how to publish a few messages to a queue, and then "flush" it, so that any messages I've published are then delivered to my subscribers. To give you an idea of what I mean, consider the following publisher code: #!/usr/bin/ruby require 'rubygems' require 'mq' MESSAGES = ["hello","goodbye","test"] AMQP.start do queue = MQ.queue('testq') messages_published = 0 while (messages_published < 50) if (rand() < 0.4) message = MESSAGES[rand(MESSAGES.size)] puts "#{Time.now.to_s}: Publishing: #{message}" queue.publish(message) messages_published += 1 end sleep(0.1) end AMQP.stop do EM.stop end end So, this code simply loops, publishing a message with 40% probability on each iteration of the loop, and then sleeps for 0.1 seconds. It does this until 50 messages have been published, and then stops AMQP. Of course, this is just a proof of concept. Now, my subscriber code: #!/usr/bin/ruby require 'rubygems' require 'mq' AMQP.start do queue = MQ.queue('testq') queue.subscribe do |header, msg| puts "#{Time.now.to_s}: Received #{msg}" end end So, we just subscribe to the queue, and for each message received, we print it out. Great, except that the subscriber only receives all 50 messages when the publisher calls AMQP.stop. Here's the output from my publisher. It has been truncated in the middle for brevity: $ ruby publisher.rb 2010-04-14 21:45:42 -0400: Publishing: test 2010-04-14 21:45:42 -0400: Publishing: hello 2010-04-14 21:45:42 -0400: Publishing: test 2010-04-14 21:45:43 -0400: Publishing: test 2010-04-14 21:45:44 -0400: Publishing: test 2010-04-14 21:45:44 -0400: Publishing: goodbye 2010-04-14 21:45:45 -0400: Publishing: goodbye 2010-04-14 21:45:45 -0400: Publishing: test 2010-04-14 21:45:45 -0400: Publishing: test . . . 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: goodbye Next, the output from my subscriber: $ ruby consumer.rb 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received hello 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received goodbye 2010-04-14 21:45:56 -0400: Received goodbye 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test . . . 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received goodbye If you note the timestamps in the output, the subscriber only receives all of the messages once the publisher has stopped AMQP and exited. So, being an AMQP newb, how can I get my messages to deliver immediately? I tried putting AMQP.start and AMQP.stop in the body of the while loop of the publisher, but then only the first message gets delivered -- though strangely, if I turn on logging, there are no error messages reported by the server and the messages do get sent to the queue, but never get received by the subscriber. Suggestions would be much appreciated. Thanks for reading.

Read the article
How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?

- by Philip Durbin

Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized: [root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen May 5 16:54:35 fs-2 kernel: ata1: SError: { PHYRdyChg CommWake } May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset May 5 16:54:45 fs-2 kernel: ata1: soft resetting link May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:54:55 fs-2 kernel: ata1: soft resetting link May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:05 fs-2 kernel: ata1: soft resetting link May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps May 5 16:55:40 fs-2 kernel: ata1: soft resetting link May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up May 5 16:55:45 fs-2 kernel: ata1: EH complete I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn't work: [root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan -bash: echo: write error: Invalid argument [root@fs-2 ~]# [root@fs-2 ~]# /root/rescan-scsi-bus.sh -l [snip] 0 new device(s) found. 0 device(s) removed. [root@fs-2 ~]# [root@fs-2 ~]# ls /dev/sda ls: /dev/sda: No such file or directory I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting? The operating system in question is RHEL5.3: [root@fs-2 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.3 (Tikanga) The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS. Here is the lscpi output: [root@fs-2 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) Update: In perhaps a dozen cases, we've been forced to reboot servers because hot swap hasn't "just worked." Thanks for the answers to look more into the SATA controller. I've included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn't supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful. The good news is that hot swap "just worked" today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output: [root@www-1 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)

Read the article
Databinding to ObservableCollection in a different UserControl - how to preserve current selections?

- by Dave

Scope of question expanded on 2010-03-25 I ended up figuring out my problem, but here's a new problem that came up as a result of solving the original question, because I want to be able to award the bounty to someone!!! Once I figured out my problem, I soon found out that when the ObservableCollection updates, the databound ComboBox has its contents repopulated, but most of the selections have been blanked out. I assume that in this case, MVVM is going to make it difficult for me to remember the last selected item. I have an idea, but it seems a little nasty. I'll award the bounty to whomever comes up with a nice solution for this! Question re-written on 2010-03-24 I have two UserControls, where one is a dialog that has a TabControl, and the other is one that appears within said TabControl. I'll just call them CandyDialog and CandyNameViewer for simplicity's sake. There's also a data management class called Tracker that manages information storage, which for all intents and purposes just exposes a public property that is an ObservableCollection. I display the CandyNameViewer in CandyDialog via code behind, like this: private void CandyDialog_Loaded( object sender, RoutedEventArgs e) { _candyviewer = new CandyViewer(); _candyviewer.DataContext = _tracker; candy_tab.Content = _candyviewer; } The CandyViewer's XAML looks like this (edited for kaxaml): <Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> <Page.Resources> <DataTemplate x:Key="CandyItemTemplate"> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="120"></ColumnDefinition> <ColumnDefinition Width="150"></ColumnDefinition> </Grid.ColumnDefinitions> <TextBox Grid.Column="0" Text="{Binding CandyName}" Margin="3"></TextBox>  <ComboBox Grid.Column="1" SelectedItem="{Binding SelectedCandy, Mode=TwoWay}" ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, Path=DataContext.CandyNames}" Margin="3"></ComboBox> </Grid> </DataTemplate> </Page.Resources> <Grid> <ListBox DockPanel.Dock="Top" ItemsSource="{Binding CandyBoxContents, Mode=TwoWay}" ItemTemplate="{StaticResource CandyItemTemplate}" /> </Grid> </Page> Now everything works fine when the controls are loaded. As long as CandyNames is populated first, and then the consumer UserControl is displayed, all of the names are there. I obviously don't get any errors in the Output Window or anything like that. The issue I have is that when the ObservableCollection is modified from the model, those changes are not reflected in the consumer UserControl! I've never had this problem before; all of my previous uses of ObservableCollection updated fine, although in those cases I wasn't databinding across assemblies. Although I am currently only adding and removing candy names to/from the ObservableCollection, at a later date I will likely also allow renaming from the model side. Is there something I did wrong? Is there a good way to actually debug this? Reed Copsey indicates here that inter-UserControl databinding is possible. Unfortunately, my favorite Bea Stollnitz article on WPF databinding debugging doesn't suggest anything that I could use for this particular problem.

Read the article
Get User SID From Logon ID (Windows XP and Up)

- by Dave Ruske

I have a Windows service that needs to access registry hives under HKEY_USERS when users log on, either locally or via Terminal Server. I'm using a WMI query on win32_logonsession to receive events when users log on, and one of the properties I get from that query is a LogonId. To figure out which registry hive I need to access, now, I need the users's SID, which is used as a registry key name beneath HKEY_USERS. In most cases, I can get this by doing a RelatedObjectQuery like so (in C#): RelatedObjectQuery relatedQuery = new RelatedObjectQuery( "associators of {Win32_LogonSession.LogonId='" + logonID + "'} WHERE AssocClass=Win32_LoggedOnUser Role=Dependent" ); where "logonID" is the logon session ID from the session query. Running the RelatedObjectQuery will generally give me a SID property that contains exactly what I need. There are two issues I have with this. First and most importantly, the RelatedObjectQuery will not return any results for a domain user that logs in with cached credentials, disconnected from the domain. Second, I'm not pleased with the performance of this RelatedObjectQuery --- it can take up to several seconds to execute. Here's a quick and dirty command line program I threw together to experiment with the queries. Rather than setting up to receive events, this just enumerates the users on the local machine: using System; using System.Collections.Generic; using System.Text; using System.Management; namespace EnumUsersTest { class Program { static void Main( string[] args ) { ManagementScope scope = new ManagementScope( "\\\\.\\root\\cimv2" ); string queryString = "select * from win32_logonsession"; // for all sessions //string queryString = "select * from win32_logonsession where logontype = 2"; // for local interactive sessions only ManagementObjectSearcher sessionQuery = new ManagementObjectSearcher( scope, new SelectQuery( queryString ) ); ManagementObjectCollection logonSessions = sessionQuery.Get(); foreach ( ManagementObject logonSession in logonSessions ) { string logonID = logonSession["LogonId"].ToString(); Console.WriteLine( "=== {0}, type {1} ===", logonID, logonSession["LogonType"].ToString() ); RelatedObjectQuery relatedQuery = new RelatedObjectQuery( "associators of {Win32_LogonSession.LogonId='" + logonID + "'} WHERE AssocClass=Win32_LoggedOnUser Role=Dependent" ); ManagementObjectSearcher userQuery = new ManagementObjectSearcher( scope, relatedQuery ); ManagementObjectCollection users = userQuery.Get(); foreach ( ManagementObject user in users ) { PrintProperties( user.Properties ); } } Console.WriteLine( "\nDone! Press a key to exit..." ); Console.ReadKey( true ); } private static void PrintProperty( PropertyData pd ) { string value = "null"; string valueType = "n/a"; if ( null == pd.Value ) value = "null"; if ( pd.Value != null ) { value = pd.Value.ToString(); valueType = pd.Value.GetType().ToString(); } Console.WriteLine( " \"{0}\" = ({1}) \"{2}\"", pd.Name, valueType, value ); } private static void PrintProperties( PropertyDataCollection properties ) { foreach ( PropertyData pd in properties ) { PrintProperty( pd ); } } } } So... is there way to quickly and reliably obtain the user SID given the information I retrieve from WMI, or should I be looking at using something like SENS instead?

Read the article
Help to solve "Robbery Problem"

- by peiska

Hello, Can anybody help me with this problem in C or Java? The problem is taken from here: http://acm.pku.edu.cn/JudgeOnline/problem?id=1104 Inspector Robstop is very angry. Last night, a bank has been robbed and the robber has not been caught. And this happened already for the third time this year, even though he did everything in his power to stop the robber: as quickly as possible, all roads leading out of the city were blocked, making it impossible for the robber to escape. Then, the inspector asked all the people in the city to watch out for the robber, but the only messages he got were of the form "We don't see him." But this time, he has had enough! Inspector Robstop decides to analyze how the robber could have escaped. To do that, he asks you to write a program which takes all the information the inspector could get about the robber in order to find out where the robber has been at which time. Coincidentally, the city in which the bank was robbed has a rectangular shape. The roads leaving the city are blocked for a certain period of time t, and during that time, several observations of the form "The robber isn't in the rectangle Ri at time ti" are reported. Assuming that the robber can move at most one unit per time step, your program must try to find the exact position of the robber at each time step. Input The input contains the description of several robberies. The first line of each description consists of three numbers W, H, t (1 <= W,H,t <= 100) where W is the width, H the height of the city and t is the time during which the city is locked. The next contains a single integer n (0 <= n <= 100), the number of messages the inspector received. The next n lines (one for each of the messages) consist of five integers ti, Li, Ti, Ri, Bi each. The integer ti is the time at which the observation has been made (1 <= ti <= t), and Li, Ti, Ri, Bi are the left, top, right and bottom respectively of the (rectangular) area which has been observed. (1 <= Li <= Ri <= W, 1 <= Ti <= Bi <= H; the point (1, 1) is the upper left hand corner, and (W, H) is the lower right hand corner of the city.) The messages mean that the robber was not in the given rectangle at time ti. The input is terminated by a test case starting with W = H = t = 0. This case should not be processed. Output For each robbery, first output the line "Robbery #k:", where k is the number of the robbery. Then, there are three possibilities: If it is impossible that the robber is still in the city considering the messages, output the line "The robber has escaped." In all other cases, assume that the robber really is in the city. Output one line of the form "Time step : The robber has been at x,y." for each time step, in which the exact location can be deduced. (x and y are the column resp. row of the robber in time step .) Output these lines ordered by time . If nothing can be deduced, output the line "Nothing known." and hope that the inspector will not get even more angry. Output a blank line after each processed case.

Read the article
Qt 4.6 Adding objects and sub-objects to QWebView window object (C++ & Javascript)

- by Cor

I am working with Qt's QWebView, and have been finding lots of great uses for adding to the webkit window object. One thing I would like to do is nested objects... for instance: in Javascript I can... var api = new Object; api.os = new Object; api.os.foo = function(){} api.window = new Object(); api.window.bar = function(){} obviously in most cases this would be done through a more OO js-framework. This results in a tidy structure of: >>>api ------------------------------------------------------- - api Object {os=Object, more... } - os Object {} foo function() - win Object {} bar function() ------------------------------------------------------- Right now I'm able to extend the window object with all of the qtC++ methods and signals I need, but they all have 'seem' to have to be in a root child of "window". This is forcing me to write a js wrapper object to get the hierarchy that I want in the DOM. >>>api ------------------------------------------------------- - api Object {os=function, more... } - os_foo function() - win_bar function() ------------------------------------------------------- This is a pretty simplified example... I want objects for parameters, etc... Does anyone know of a way to pass an child object with the object that extends the WebFrame's window object? Here's some example code of how I'm adding the object: mainwindow.h #ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QtGui/QMainWindow> #include <QWebFrame> #include "mainwindow.h" #include "happyapi.h" class QWebView; class QWebFrame; QT_BEGIN_NAMESPACE class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = 0); private slots: void attachWindowObject(); void bluesBros(); private: QWebView *view; HappyApi *api; QWebFrame *frame; }; #endif // MAINWINDOW_H mainwindow.cpp #include <QDebug> #include <QtGui> #include <QWebView> #include <QWebPage> #include "mainwindow.h" #include "happyapi.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) { view = new QWebView(this); view->load(QUrl("file:///Q:/example.htm")); api = new HappyApi(this); QWebPage *page = view->page(); frame = page->mainFrame(); attachWindowObject(); connect(frame, SIGNAL(javaScriptWindowObjectCleared()), this, SLOT(attachWindowObject())); connect(api, SIGNAL(win_bar()), this, SLOT(bluesBros())); setCentralWidget(view); }; void MainWindow::attachWindowObject() { frame->addToJavaScriptWindowObject(QString("api"), api); }; void MainWindow::bluesBros() { qDebug() << "foo and bar are getting the band back together!"; }; happyapi.h #ifndef HAPPYAPI_H #define HAPPYAPI_H #include <QObject> class HappyApi : public QObject { Q_OBJECT public: HappyApi(QObject *parent); public slots: void os_foo(); signals: void win_bar(); }; #endif // HAPPYAPI_H happyapi.cpp #include <QDebug> #include "happyapi.h" HappyApi::HappyApi(QObject *parent) : QObject(parent) { }; void HappyApi::os_foo() { qDebug() << "foo called, it want's it's bar back"; }; I'm reasonably new to C++ programming (coming from a web and python background). Hopefully this example will serve to not only help other new users, but be something interesting for a more experienced c++ programmer to elaborate on. Thanks for any assistance that can be provided. :)

Read the article
Concat wchar_t Unicode strings in C?

- by Doori Bar

I'm a beginner, I play with FindFirstFileW() of the winapi - C. The unicoded path is: " \\?\c:\Français\", and I would like to concat "*" to this path of type wchar_t (then I will use it as an arg for FindFirstFileW()). I made two test cases of mine, the first is ansi_string() which seem to work fine, the second is unicode_string() - which I don't quite understand how should I concat the additional "*" char to the unicoded path. I write the strings to a file, because I'm not able to print Unicoded characters to stdout. Note: my goal is to learn, which means I'll appreciate guidance and references to the appropriate resources regards my scenario, I'm very much a beginner and this is my first attempt with Unicode. Thanks, Doori Bar #include <stdio.h> #include <stdlib.h> #include <wchar.h> #include <string.h> #include <errno.h> void *error_malloc(int size); void ansi_string(char **str1, char **str2); void unicode_string(wchar_t **wstr1, wchar_t **wstr2); void unicode_string(wchar_t **wstr1, wchar_t **wstr2) { /* assign wstr1 with the path: \\?\c:\Français\ */ *wstr1 = error_malloc((wcslen(L"\\\\?\\c:\\Français\\")+1) *sizeof(**wstr1)); wcscpy(*wstr1,L"\\\\?\\c:\\Français\\"); /* concat wstr1+"*" , assign wstr2 with: \\?\c:\Français\* */ *wstr2 = error_malloc((wcslen(*wstr1) + 1 + 1) * sizeof(**wstr1)); /* swprintf(*wstr2,"%ls*",*wstr1); */ /* how should I concat wstr1+"*"? */ wcscpy(*wstr2,L"\\\\?\\c:\\Français\\"); } void ansi_string(char **str1, char **str2) { /* assign str1 with the path: c:\English\ */ *str1 = error_malloc(strlen("c:\\English\\") + 1); strcpy(*str1,"c:\\English\\"); /* concat str1+"*" , assign str2 with: c:\English\* */ *str2 = error_malloc(strlen(*str1) + 1 + 1); sprintf(*str2,"%s*",*str1); } void *error_malloc(int size) { void *ptr; int errornumber; if ((ptr = malloc(size)) == NULL) { errornumber = errno; fprintf(stderr,"Error: malloc(): %d; Error Message: %s;\n", errornumber,strerror(errornumber)); exit(1); } return ptr; } int main(void) { FILE *outfile; char *str1; char *str2; wchar_t *wstr1; wchar_t *wstr2; if ((outfile = fopen("out.bin","w")) == NULL) { printf("Error: fopen failed."); return 1; } ansi_string(&str1,&str2); fwrite(str2, sizeof(*str2), strlen(str2), outfile); printf("strlen: %d\n",strlen(str2)); printf("sizeof: %d\n",sizeof(*str2)); free(str1); free(str2); unicode_string(&wstr1,&wstr2); fwrite(wstr2, sizeof(*wstr2), wcslen(wstr2), outfile); printf("wcslen: %d\n",wcslen(wstr2)); printf("sizeof: %d\n",sizeof(*wstr2)); free(wstr1); free(wstr2); fclose(outfile); return 0; }

Read the article
Process spawned by exec-maven-plugin blocks the maven process

- by Arnab Biswas

I am trying to execute the following scenario using maven : pre-integration-phase : Start a java based application using a main class (using exec-maven-plugin) integration-phase : Run the integration test cases (using maven-failsafe-plugin) post-integration-phase: Stop the application gracefully (using exec-maven-plugin) Here is pom.xml snip: <plugins> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>exec-maven-plugin</artifactId> <version>1.2.1</version> <executions> <execution> <id>launch-myApp</id> <phase>pre-integration-test</phase> <goals> <goal>exec</goal> </goals> </execution> </executions> <configuration> <executable>java</executable> <arguments> <argument>-DMY_APP_HOME=/usr/home/target/local</argument> <argument>-Djava.library.path=/usr/home/other/lib</argument> <argument>-classpath</argument> <classpath/> <argument>com.foo.MyApp</argument> </arguments> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-failsafe-plugin</artifactId> <version>2.12</version> <executions> <execution> <goals> <goal>integration-test</goal> <goal>verify</goal> </goals> </execution> </executions> <configuration> <forkMode>always</forkMode> </configuration> </plugin> </plugins> If I execute mvn post-integration-test, my application is getting started as a child process of the maven process, but the application process is blocking the maven process from executing the integration tests which comes in the next phase. Later I found that there is a bug (or missing functionality?) in maven exec plugin, because of which the application process blocks the maven process. To address this issue, I have encapsulated the invocation of MyApp.java in a shell script and then appended “/dev/null 2&1 &” to spawn a separate background process. Here is the snip (this is just a snip and not the actual one) from runTest.sh: java - DMY_APP_HOME =$2 com.foo.MyApp > /dev/null 2>&1 & Although this solves my issue, is there any other way to do it? Am I missing any argument for exec-maven-plugin?

Read the article
How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?

- by Philip Durbin

Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized: [root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen May 5 16:54:35 fs-2 kernel: ata1: SError: { PHYRdyChg CommWake } May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset May 5 16:54:45 fs-2 kernel: ata1: soft resetting link May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:54:55 fs-2 kernel: ata1: soft resetting link May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:05 fs-2 kernel: ata1: soft resetting link May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps May 5 16:55:40 fs-2 kernel: ata1: soft resetting link May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up May 5 16:55:45 fs-2 kernel: ata1: EH complete I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn't work: [root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan -bash: echo: write error: Invalid argument [root@fs-2 ~]# [root@fs-2 ~]# /root/rescan-scsi-bus.sh -l [snip] 0 new device(s) found. 0 device(s) removed. [root@fs-2 ~]# [root@fs-2 ~]# ls /dev/sda ls: /dev/sda: No such file or directory I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting? The operating system in question is RHEL5.3: [root@fs-2 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.3 (Tikanga) The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS. Here is the lscpi output: [root@fs-2 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) Update: In perhaps a dozen cases, we've been forced to reboot servers because hot swap hasn't "just worked." Thanks for the answers to look more into the SATA controller. I've included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn't supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful. The good news is that hot swap "just worked" today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output: [root@www-1 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)

Read the article
jQuery dynamic field classes not being assigned as desired.

- by Simon

Hello, I'm working on a fancy login page with 4 unique states attributed through classes for each field (normal, focus, active-on, active-off). Normal is the default style. Focus is the focus style when nothing is typed. Active-on is the focus style when something has been typed. Active-off is for field that have user text in them, but are not focused right now. Here's a demo to help you understand what I'm doing: http://www.controlstack.com/login My JS is working almost correctly (thanks to some folks on this site), except in 2 cases: If I enter something in the username field, then tab over to the password field, it does not add the ".focus" class to the password field. If I blur out of the username field, then focus back on it, enter a few characters, then delete them, it does not add the ".focus" field. Here's my code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" dir="ltr"> <head> <title>Login</title> <style> input.field {height: 39px; width: 194px; background: url(login-fields.png) no-repeat; overflow: hidden; border: none; outline: none; float: left; margin-right: 7px;} input.field#username {padding: 0 12px;} input.field#username.focus {background-position: 0 -39px;} input.field#username.active-on {background-position: 0 -78px;} input.field#username.active-off {background-position: 0 -117px;} input.field#password {background-position: -218px 0; padding: 0 12px;} input.field#password.focus {background-position: -218px -39px;} input.field#password.active-on {background-position: -218px -78px;} input.field#password.active-off {background-position: -218px -117px;} input.field#go {background-position: -436px 0; width: 88px; margin: 0; cursor: pointer;} </style> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script> <script type="text/javascript"> $(document).ready(function() { loginField = $('.field'); firstField = $('.field.first'); firstField.focus(); loginField.focus(function(){ loginVal1 = loginField.val(); if (!loginVal1){ $(this).removeClass('active-off').addClass('focus'); } else { $(this).removeClass('active-off').addClass('active-on'); } }); loginField.live('keydown', function(){ $(this).addClass('active-on').removeClass('active-off'); }).live('keyup', function(){ $(this).toggleClass('active-on', $(this).val() != ''); }) loginField.blur(function(){ loginVal2 = loginField.val(); if (!loginVal2){ $(this).removeClass('focus').removeClass('active-on'); $(this).val(''); } else { $(this).removeClass('focus').removeClass('active-on').addClass('active-off'); } }); }); </script> </head> <body> <h1>Login to your account</h1> <form method="post" action="/"> <fieldset> <input type="text" class="field first focus" id="username" /> <input type="text" class="field" id="password" /> <input type="submit" value="" class="field" id="go" alt="login" title="login" /> </fieldset> </form> </body> </html> Your help is much appreciated!

Read the article
Allocation algorithm help, using Python.

- by Az

Hi there, I've been working on this general allocation algorithm for students. The pseudocode for it (a Python implementation) is: for a student in a dictionary of students: for student's preference in a set of preferences (ordered from 1 to 10): let temp_project be the first preferred project check if temp_project is available if so, allocate it to them and make the project UNavailable to others Quite simply this will try to allocate projects by starting from their most preferred. The way it works, out of a set of say 100 projects, you list 10 you would want to do. So the 10th project wouldn't be the "least preferred overall" but rather the least preferred in their chosen set, which isn't so bad. Obviously if it can't allocate a project, a student just reverts to the base case which is an allocation of None, with a rank of 11. What I'm doing is calculating the allocation "quality" based on a weighted sum of the ranks. So the lower the numbers (i.e. more highly preferred projects), the better the allocation quality (i.e. more students have highly preferred projects). That's basically what I've currently got. Simple and it works. Now I'm working on this algorithm that tries to minimise the allocation weight locally (this pseudocode is a bit messy, sorry). The only reason this will probably work is because my "search space" as it is, isn't particularly large (just a very general, anecdotal observation, mind you). Since the project is only specific to my Department, we have their own limits imposed. So the number of students can't exceed 100 and the number of preferences won't exceed 10. for student in a dictionary/list/whatever of students: where i = 0 take the (i)st student, (i+1)nd student for their ranks: allocate the projects and set local_weighting to be sum(student_i.alloc_proj_rank, student_i+1.alloc_proj_rank) these are the cases: if local_weighting is 2 (i.e. both ranks are 1): then i += 1 and and continue above if local weighting is = N>2 (i.e. one or more ranks are greater than 1): let temp_local_weighting be N: pick student with lowest rank and then move him to his next rank and pick the other student and reallocate his project after this if temp_local_weighting is < N: then allocate those projects to the students move student with lowest rank to the next rank and reallocate other if temp_local_weighting < previous_temp_allocation: let these be the new allocated projects try moving for the lowest rank and reallocate other else: if this weighting => previous_weighting let these be the allocated projects i += 1 and move on for the rest of the students So, questions: This is sort of a modification of simulated annealing, but any sort of comments on this would be appreciated. How would I keep track of which student is (i) and which student is (i+1) If my overall list of students is 100, then the thing would mess up on (i+1) = 101 since there is none. How can I circumvent that? Any immediate flaws that can be spotted? Extra info: My students dictionary is designed as such: students[student_id] = Student(student_id, student_name, alloc_proj, alloc_proj_rank, preferences) where preferences is in the form of a dictionary such that preferences[rank] = {project_id}

Read the article
Unit Testing Refcounted Critical Section Class

- by BillyONeal

Hello all :) I'm looking at a simple class I have to manage critical sections and locks, and I'd like to cover this with test cases. Does this make sense, and how would one go about doing it? It's difficult because the only way to verify the class works is to setup very complicated threading scenarios, and even then there's not a good way to test for a leak of a Critical Section in Win32. Is there a more direct way to make sure it's working correctly? Here's the code: CriticalSection.hpp: #pragma once #include <windows.h> namespace WindowsAPI { namespace Threading { class CriticalSection; class CriticalLock { std::size_t *instanceCount; CRITICAL_SECTION * criticalStructure; bool lockValid; friend class CriticalSection; CriticalLock(std::size_t *, CRITICAL_SECTION *, bool); public: bool IsValid() { return lockValid; }; void Unlock(); ~CriticalLock() { Unlock(); }; }; class CriticalSection { std::size_t *instanceCount; CRITICAL_SECTION * criticalStructure; public: CriticalSection(); CriticalSection(const CriticalSection&); CriticalSection& operator=(const CriticalSection&); CriticalSection& swap(CriticalSection&); ~CriticalSection(); CriticalLock Enter(); CriticalLock TryEnter(); }; }} CriticalSection.cpp: #include "CriticalSection.hpp" namespace WindowsAPI { namespace Threading { CriticalSection::CriticalSection() { criticalStructure = new CRITICAL_SECTION; instanceCount = new std::size_t; *instanceCount = 1; InitializeCriticalSection(criticalStructure); } CriticalSection::CriticalSection(const CriticalSection& other) { criticalStructure = other.criticalStructure; instanceCount = other.instanceCount; instanceCount++; } CriticalSection& CriticalSection::operator=(const CriticalSection& other) { CriticalSection copyOfOther(other); swap(copyOfOther); return *this; } CriticalSection& CriticalSection::swap(CriticalSection& other) { std::swap(other.instanceCount, instanceCount); std::swap(other.criticalStructure, other.criticalStructure); return *this; } CriticalSection::~CriticalSection() { if (!--(*instanceCount)) { DeleteCriticalSection(criticalStructure); delete criticalStructure; delete instanceCount; } } CriticalLock CriticalSection::Enter() { EnterCriticalSection(criticalStructure); (*instanceCount)++; return CriticalLock(instanceCount, criticalStructure, true); } CriticalLock CriticalSection::TryEnter() { bool lockAquired; if (TryEnterCriticalSection(criticalStructure)) { (*instanceCount)++; lockAquired = true; } else lockAquired = false; return CriticalLock(instanceCount, criticalStructure, lockAquired); } void CriticalLock::Unlock() { if (!lockValid) return; LeaveCriticalSection(criticalStructure); lockValid = false; if (!--(*instanceCount)) { DeleteCriticalSection(criticalStructure); delete criticalStructure; delete instanceCount; } } }}

Read the article
How to debug EXC_BAD_ACCESS that occurs only on release target for an iPhone app?

- by Bobby Moretti

I'm developing an iPhone application. I have an EXC_BAD_ACCESS that occurs only in the release target; when I build the debug target the exception does not occur. However, when I set the NSZombieEnabled environment variable to YES, I still get the EXC_BAD_ACCESS with no further information. Is it even possible for NSZombieEnabled to work when executing the release target? I don't see why not, since gdb is running in both cases... Update: here is a printout of the top of the stack: #0 0x33369ebc in objc_msgSend () #1 0x3144f968 in -[EAInputStream _streamEventTrigger] () #2 0x3144fe78 in __streamEventTrigger () #3 0x338ae3a6 in CFRunLoopRunSpecific () #4 0x338adc1e in CFRunLoopRunInMode () #5 0x32ed6966 in -[NSRunLoop(NSRunLoop) runMode:beforeDate:] () #6 0x00005b06 in -[IOStreamDelegate removeMsg:] (self=0x142cc0, _cmd=<value temporarily unavailable, due to optimizations>, message=0x2fffe544) at /Users/robertmoretti/Documents/XXXXXXX/IOStreamDelegate.m:191 Here is a gdb session from inside the objc_msgSend call at the top: (gdb) p/x $r0 $6 = 0x3100000 (gdb) x/s $r1 0x32d7cff8: "release" (gdb) disassemble $pc Dump of assembler code for function objc_msgSend: 0x33369ea8 <objc_msgSend+0>: teq r0, #0 ; 0x0 0x33369eac <objc_msgSend+4>: moveq r1, #0 ; 0x0 0x33369eb0 <objc_msgSend+8>: bxeq lr 0x33369eb4 <objc_msgSend+12>: push {r3, r4, r5, r6} 0x33369eb8 <objc_msgSend+16>: ldr r4, [r0] 0x33369ebc <objc_msgSend+20>: ldr r5, [r4, #8] 0x33369ec0 <objc_msgSend+24>: ldr r6, [r5] 0x33369ec4 <objc_msgSend+28>: add r3, r5, #8 ; 0x8 0x33369ec8 <objc_msgSend+32>: and r5, r6, r1, lsr #2 0x33369ecc <objc_msgSend+36>: ldr r4, [r3, r5, lsl #2] 0x33369ed0 <objc_msgSend+40>: teq r4, #0 ; 0x0 0x33369ed4 <objc_msgSend+44>: add r5, r5, #1 ; 0x1 0x33369ed8 <objc_msgSend+48>: beq 0x33369efc <objc_msgSend+84> 0x33369edc <objc_msgSend+52>: ldr r12, [r4] 0x33369ee0 <objc_msgSend+56>: teq r1, r12 0x33369ee4 <objc_msgSend+60>: and r5, r5, r6 0x33369ee8 <objc_msgSend+64>: bne 0x33369ecc <objc_msgSend+36> 0x33369eec <objc_msgSend+68>: ldr r12, [r4, #8] 0x33369ef0 <objc_msgSend+72>: teq r4, r4 0x33369ef4 <objc_msgSend+76>: pop {r3, r4, r5, r6} 0x33369ef8 <objc_msgSend+80>: bx r12 0x33369efc <objc_msgSend+84>: pop {r3, r4, r5, r6} 0x33369f00 <objc_msgSend+88>: b 0x33369f04 <objc_msgSend_uncached> End of assembler dump. (gdb) p/x *$r0 $9 = 0x0 The exception occurs on the line 0x33369ebc <objc_msgSend+20>: ldr r5, [r4, #8]. r4 has just been given the value pointed to by r0, which happens to be 0. I am wondering what is supposed to be in the memory region of 0x3100000. Here's a memory dump of that area: (gdb) x/256w 0x3100000 0x3100000: 0x00000000 0x0000a293 0xaa650505 0x00000000 0x3100010: 0x0000a294 0xaa670505 0x00000000 0x0000a295 0x3100020: 0xaa690505 0x00000000 0x0000a296 0xaa6b0505 0x3100030: 0x00000000 0x0000a297 0xaa6d0505 0x00000000 0x3100040: 0x0000a298 0xaa6f0505 0x00000000 0x0000a299 0x3100050: 0xaa710505 0x00000000 0x0000a29a 0xaa730505 0x3100060: 0x00000000 0x0000a29b 0xaa750505 0x00000000 0x3100070: 0x0000a29c 0xaa770505 0x00000000 0x0000a29d 0x3100080: 0xaa790505 0x00000000 0x0000a29e 0xaa7b0505 0x3100090: 0x00000000 0x0000a29f 0xaa7d0505 0x00000000 0x31000a0: 0x0000a2a0 0xaa7f0505 0x00000000 0x0000a2a1 0x31000b0: 0xaa810505 0x00000000 0x0000a2a2 0xaa830505 0x31000c0: 0x00000000 0x0000a2a3 0xaa850505 0x00000000 0x31000d0: 0x0000a2a4 0xaa870505 0x00000000 0x0000a2a5 0x31000e0: 0xaa890505 0x00000000 0x0000a2a6 0xaa8b0505 0x31000f0: 0x00000000 0x0000a2a7 0xaa8d0505 0x00000000 0x3100100: 0x0000a2a8 0xaa8f0505 0x00000000 0x0000a2a9 0x3100110: 0xaa910505 0x00000000 0x0000a2aa 0xaa930505 0x3100120: 0x00000000 0x0000a2ab 0xaa950505 0x00000000 0x3100130: 0x0000a2ac 0xaa970505 0x00000000 0x0000a2ad 0x3100140: 0xaa990505 0x00000000 0x0000a2ae 0xaa9b0505 0x3100150: 0x00000000 0x0000a2af 0xaa9d0505 0x00000000 0x3100160: 0x0000a2b0 0xaa9f0505 0x00000000 0x0000a2b1 0x3100170: 0xaaa10505 0x00000000 0x0000a2b2 0xaaa30505 0x3100180: 0x00000000 0x0000a2b3 0xaaa50505 0x00000000 0x3100190: 0x0000a2b4 0xaaa70505 0x00000000 0x0000a2b5 0x31001a0: 0xaaa90505 0x00000000 0x0000a2b6 0xaaab0505 0x31001b0: 0x00000000 0x0000a2b7 0xaaad0505 0x00000000 0x31001c0: 0x0000a2b8 0xaaaf0505 0x00000000 0x0000a2b9 0x31001d0: 0xaab10505 0x00000000 0x0000a2ba 0xaab30505 0x31001e0: 0x00000000 0x0000a2bb 0xaab50505 0x00000000 0x31001f0: 0x0000a2bc 0xaab70505 0x00000000 0x0000a2bd 0x3100200: 0xaab90505 0x00000000 0x0000a2be 0xaabb0505 0x3100210: 0x00000000 0x0000a2bf 0xaabd0505 0x00000000 0x3100220: 0x0000a2c0 0xaabf0505 0x00000000 0x0000a2c1 0x3100230: 0xaac10505 0x00000000 0x0000a2c2 0xaac30505 0x3100240: 0x00000000 0x0000a2c3 0xaac50505 0x00000000 0x3100250: 0x0000a2c4 0xaac70505 0x00000000 0x0000a2c5 0x3100260: 0xaac90505 0x00000000 0x0000a2c6 0xaacb0505 0x3100270: 0x00000000 0x0000a2c7 0xaacd0505 0x00000000 0x3100280: 0x0000a2c8 0xaacf0505 0x00000000 0x0000a2c9 0x3100290: 0xaad10505 0x00000000 0x0000a2ca 0xaad30505 0x31002a0: 0x00000000 0x0000a2cb 0xaad50505 0x00000000 0x31002b0: 0x0000a2cc 0xaad70505 0x00000000 0x0000a2cd 0x31002c0: 0xaad90505 0x00000000 0x0000a2ce 0xaadb0505 0x31002d0: 0x00000000 0x0000a2cf 0xaadd0505 0x00000000 0x31002e0: 0x0000a2d0 0xaadf0505 0x00000000 0x0000a2d1 0x31002f0: 0xaae10505 0x00000000 0x0000a2d2 0xaae30505 0x3100300: 0x00000000 0x0000a2d3 0xaae50505 0x00000000 0x3100310: 0x0000a2d4 0xaae70505 0x00000000 0x0000a2d5 0x3100320: 0xaae90505 0x00000000 0x0000a2d6 0xaaeb0505 0x3100330: 0x00000000 0x0000a2d7 0xaaed0505 0x00000000 0x3100340: 0x0000a2d8 0xaaef0505 0x00000000 0x0000a2d9 0x3100350: 0xaaf10505 0x00000000 0x0000a2da 0xaaf30505 0x3100360: 0x00000000 0x0000a2db 0xaaf50505 0x00000000 0x3100370: 0x0000a2dc 0xaaf70505 0x00000000 0x0000a2dd 0x3100380: 0xaaf90505 0x00000000 0x0000a2de 0xaafb0505 0x3100390: 0x00000000 0x0000a2df 0xaafd0505 0x00000000 0x31003a0: 0x0000a2e0 0xab050505 0x00000000 0x0000a2e1 0x31003b0: 0xab070505 0x00000000 0x0000a2e2 0xab090505 0x31003c0: 0x00000000 0x0000a2e3 0xab0b0505 0x00000000 0x31003d0: 0x0000a2e4 0xab0d0505 0x00000000 0x0000a2e5 0x31003e0: 0xab0f0505 0x00000000 0x0000a2e6 0xab110505 0x31003f0: 0x00000000 0x0000a2e7 0xab130505 0x00000000 I don't really know what else to try; hopefully someone with more iphone experience will be able to recognize this memory as something meaningful.

Read the article
Query doesn't use a covering-index when applicable

- by Dor

I've downloaded the employees database and executed some queries for benchmarking purposes. Then I noticed that one query didn't use a covering index, although there was a corresponding index that I created earlier. Only when I added a FORCE INDEX clause to the query, it used a covering index. I've uploaded two files, one is the executed SQL queries and the other is the results. Can you tell why the query uses a covering-index only when a FORCE INDEX clause is added? The EXPLAIN shows that in both cases, the index dept_no_from_date_idx is being used anyway. To adapt myself to the standards of SO, I'm also writing the content of the two files here: The SQL queries: USE employees; /* Creating an index for an index-covered query */ CREATE INDEX dept_no_from_date_idx ON dept_emp (dept_no, from_date); /* Show `dept_emp` table structure, indexes and generic data */ SHOW TABLE STATUS LIKE "dept_emp"; DESCRIBE dept_emp; SHOW KEYS IN dept_emp; /* The EXPLAIN shows that the subquery doesn't use a covering-index */ EXPLAIN SELECT SQL_NO_CACHE * FROM dept_emp INNER JOIN ( /* The subquery should use a covering index, but isn't */ SELECT SQL_NO_CACHE emp_no, dept_no FROM dept_emp WHERE dept_no="d001" ORDER BY from_date DESC LIMIT 20000,50 ) AS `der` USING (`emp_no`, `dept_no`); /* The EXPLAIN shows that the subquery DOES use a covering-index, thanks to the FORCE INDEX clause */ EXPLAIN SELECT SQL_NO_CACHE * FROM dept_emp INNER JOIN ( /* The subquery use a covering index */ SELECT SQL_NO_CACHE emp_no, dept_no FROM dept_emp FORCE INDEX(dept_no_from_date_idx) WHERE dept_no="d001" ORDER BY from_date DESC LIMIT 20000,50 ) AS `der` USING (`emp_no`, `dept_no`); The results: -------------- /* Creating an index for an index-covered query */ CREATE INDEX dept_no_from_date_idx ON dept_emp (dept_no, from_date) -------------- Query OK, 331603 rows affected (33.95 sec) Records: 331603 Duplicates: 0 Warnings: 0 -------------- /* Show `dept_emp` table structure, indexes and generic data */ SHOW TABLE STATUS LIKE "dept_emp" -------------- +----------+--------+---------+------------+--------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+---------+ | Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment | +----------+--------+---------+------------+--------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+---------+ | dept_emp | InnoDB | 10 | Compact | 331883 | 36 | 12075008 | 0 | 21544960 | 29360128 | NULL | 2010-05-04 13:07:49 | NULL | NULL | utf8_general_ci | NULL | | | +----------+--------+---------+------------+--------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+----------+----------------+---------+ 1 row in set (0.47 sec) -------------- DESCRIBE dept_emp -------------- +-----------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+---------+------+-----+---------+-------+ | emp_no | int(11) | NO | PRI | NULL | | | dept_no | char(4) | NO | PRI | NULL | | | from_date | date | NO | | NULL | | | to_date | date | NO | | NULL | | +-----------+---------+------+-----+---------+-------+ 4 rows in set (0.05 sec) -------------- SHOW KEYS IN dept_emp -------------- +----------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +----------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | dept_emp | 0 | PRIMARY | 1 | emp_no | A | 331883 | NULL | NULL | | BTREE | | | dept_emp | 0 | PRIMARY | 2 | dept_no | A | 331883 | NULL | NULL | | BTREE | | | dept_emp | 1 | emp_no | 1 | emp_no | A | 331883 | NULL | NULL | | BTREE | | | dept_emp | 1 | dept_no | 1 | dept_no | A | 7 | NULL | NULL | | BTREE | | | dept_emp | 1 | dept_no_from_date_idx | 1 | dept_no | A | 13 | NULL | NULL | | BTREE | | | dept_emp | 1 | dept_no_from_date_idx | 2 | from_date | A | 165941 | NULL | NULL | | BTREE | | +----------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ 6 rows in set (0.23 sec) -------------- /* The EXPLAIN shows that the subquery doesn't use a covering-index */ EXPLAIN SELECT SQL_NO_CACHE * FROM dept_emp INNER JOIN ( /* The subquery should use a covering index, but isn't */ SELECT SQL_NO_CACHE emp_no, dept_no FROM dept_emp WHERE dept_no="d001" ORDER BY from_date DESC LIMIT 20000,50 ) AS `der` USING (`emp_no`, `dept_no`) -------------- +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+-------------+ | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 50 | | | 1 | PRIMARY | dept_emp | eq_ref | PRIMARY,emp_no,dept_no,dept_no_from_date_idx | PRIMARY | 16 | der.emp_no,der.dept_no | 1 | | | 2 | DERIVED | dept_emp | ref | dept_no,dept_no_from_date_idx | dept_no_from_date_idx | 12 | | 21402 | Using where | +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+-------------+ 3 rows in set (0.09 sec) -------------- /* The EXPLAIN shows that the subquery DOES use a covering-index, thanks to the FORCE INDEX clause */ EXPLAIN SELECT SQL_NO_CACHE * FROM dept_emp INNER JOIN ( /* The subquery use a covering index */ SELECT SQL_NO_CACHE emp_no, dept_no FROM dept_emp FORCE INDEX(dept_no_from_date_idx) WHERE dept_no="d001" ORDER BY from_date DESC LIMIT 20000,50 ) AS `der` USING (`emp_no`, `dept_no`) -------------- +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+--------------------------+ | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 50 | | | 1 | PRIMARY | dept_emp | eq_ref | PRIMARY,emp_no,dept_no,dept_no_from_date_idx | PRIMARY | 16 | der.emp_no,der.dept_no | 1 | | | 2 | DERIVED | dept_emp | ref | dept_no_from_date_idx | dept_no_from_date_idx | 12 | | 37468 | Using where; Using index | +----+-------------+------------+--------+----------------------------------------------+-----------------------+---------+------------------------+-------+--------------------------+ 3 rows in set (0.05 sec) Bye

Read the article
Help me alter this query to get the desired results - New*

- by sandeepan

Please dump these data first CREATE TABLE IF NOT EXISTS `all_tag_relations` ( `id_tag_rel` int(10) NOT NULL AUTO_INCREMENT, `id_tag` int(10) unsigned NOT NULL DEFAULT '0', `id_tutor` int(10) DEFAULT NULL, `id_wc` int(10) unsigned DEFAULT NULL, PRIMARY KEY (`id_tag_rel`), KEY `All_Tag_Relations_FKIndex1` (`id_tag`), KEY `id_wc` (`id_wc`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=19 ; INSERT INTO `all_tag_relations` (`id_tag_rel`, `id_tag`, `id_tutor`, `id_wc`) VALUES (1, 1, 1, NULL), (2, 2, 1, NULL), (3, 6, 2, NULL), (4, 7, 2, NULL), (8, 3, 1, 1), (9, 4, 1, 1), (10, 5, 2, 2), (11, 4, 2, 2), (15, 8, 1, 3), (16, 9, 1, 3), (17, 10, 1, 4), (18, 4, 1, 4), (19, 1, 2, 5), (20, 4, 2, 5); CREATE TABLE IF NOT EXISTS `tags` ( `id_tag` int(10) unsigned NOT NULL AUTO_INCREMENT, `tag` varchar(255) DEFAULT NULL, PRIMARY KEY (`id_tag`), UNIQUE KEY `tag` (`tag`), KEY `id_tag` (`id_tag`), KEY `tag_2` (`tag`), KEY `tag_3` (`tag`), KEY `tag_4` (`tag`), FULLTEXT KEY `tag_5` (`tag`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=11 ; INSERT INTO `tags` (`id_tag`, `tag`) VALUES (1, 'Sandeepan'), (2, 'Nath'), (3, 'first'), (4, 'class'), (5, 'new'), (6, 'Bob'), (7, 'Cratchit'), (8, 'more'), (9, 'fresh'), (10, 'second'); CREATE TABLE IF NOT EXISTS `webclasses` ( `id_wc` int(10) NOT NULL AUTO_INCREMENT, `id_author` int(10) NOT NULL, `name` varchar(50) DEFAULT NULL, PRIMARY KEY (`id_wc`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ; INSERT INTO `webclasses` (`id_wc`, `id_author`, `name`) VALUES (1, 1, 'first class'), (2, 2, 'new class'), (3, 1, 'more fresh'), (4, 1, 'second class'), (5, 2, 'sandeepan class'); About the system - The system consists of tutors and classes. - The data in the table All_Tag_Relations stores tag relations for each tutor registered and each class created by a tutor. The tag relations are used for searching classes. The current data dump corresponds to tutor "Sandeepan Nath" who has created classes named "first class", "more fresh", "second class" and tutor "Bob Cratchit" who has created classes "new class" and "Sandeepan class". I am trying for a search query performs AND logic on the search keywords and returns wvery such class for which the search terms are present in the class name or its tutor name To make it easy, following is the list of search terms and desired results:- Search term result classes (check the id_wc in the results) first class 1 Sandeepan Nath class 1 Sandeepan Nath 1,3 Bob Cratchit 2 Sandeepan Nath bob none Sandeepan Class 1,4,5 I have so far reached upto this query -- Two keywords search SET @tag1 = 4, @tag2 = 1; -- Setting some user variables to see where the ids go. SELECT wc.id_wc, sum( DISTINCT ( wtagrels.id_tag = @tag1 ) ) AS key_1_class_matches, sum( DISTINCT ( wtagrels.id_tag = @tag2 ) ) AS key_2_class_matches, sum( DISTINCT ( ttagrels.id_tag = @tag1 ) ) AS key_1_tutor_matches, sum( DISTINCT ( ttagrels.id_tag = @tag2 ) ) AS key_2_tutor_matches, sum( DISTINCT ( ttagrels.id_tag = wtagrels.id_tag ) ) AS key_class_tutor_matches FROM WebClasses as wc join all_tag_relations AS wtagrels on wc.id_wc = wtagrels.id_wc join all_tag_relations as ttagrels on (wc.id_author = ttagrels.id_tutor) WHERE ( wtagrels.id_tag = @tag1 OR wtagrels.id_tag = @tag2 OR ttagrels.id_tag = @tag1 OR ttagrels.id_tag = @tag2 ) GROUP BY wtagrels.id_wc LIMIT 0 , 20 For search with 1 or 3 terms, remove/add the variable part in this query. Tabulating my observation of the values of key_1_class_matches, key_2_class_matches,key_1_tutor_matches (say, class keys),key_2_tutor_matches for various cases (say, tutor keys). Search term expected result Observation first class 1 for class 1, all class keys+all tutor keys =1 Sandeepan Nath class 1 for class 1, one class key+ all tutor keys = 1 Sandeepan Nath 1,3 both tutor keys =1 for these classes Bob Cratchit 2 both tutor keys = 1 Sandeepan Nath bob none no complete tutor matches for any class I found a pattern that, for any case, the class(es) which should appear in the result have the highest number of matches (all class keys and tutor keys). E.g. searching "first class", only for class =1, total of key matches = 4(1+1+1+1) searching "Sandeepan Nath", for classes 1, 3,4(all classes by Sandeepan Nath) have all the tutor keys matching. But no pattern in the search for "Sandeepan Class" - classes 1,4,5 should match. Now, how do I put a condition into the query, based on that pattern so that only those classes are returned. Do I need to use full text search here because it gives a scoring/rank value indicating the strength of the match? Any sample query would help. Please note - I have already found solution for showing classes when any/all of the search terms match with the class name. http://stackoverflow.com/questions/3030022/mysql-help-me-alter-this-search-query-to-get-desired-results But if all the search terms are in tutor name, it does not work. So, I am modifying the query and experimenting.

Read the article

Search Results

Search found 6945 results on 278 pages for 'azure use cases'.

Page 263/278 | < Previous Page | 259 260 261 262 263 264 265 266 267 268 269 270 | Next Page >

- by Matt

- by pacoder

- by Pickledegg

- by Greg

- by WishCow

- by Andras Zoltan

- by Peter Lee

- by RexOnRoids

- by Steve Sheldon

- by Swoop

- by jeffshantz

- by Philip Durbin

- by Dave

- by Dave Ruske

- by peiska

- by Cor

- by Doori Bar

- by Arnab Biswas

- by Philip Durbin

- by Simon

- by Az

- by BillyONeal

- by Bobby Moretti

- by Dor

- by sandeepan

< Previous Page | 259 260 261 262 263 264 265 266 267 268 269 270 | Next Page >