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  • Zend_Auth / Zend_Session error and storing objects in Auth Storage

    - by Martin
    Hi All, I have been having a bit of a problem with Zend_Auth and keep getting an error within my Acl. Within my Login Controller I setup my Zend_Auth storage as follows $auth = Zend_Auth::getInstance(); $result = $auth->authenticate($adapter); if ($result->isValid()) { $userId = $adapter->getResultRowObject(array('user_id'), null)->user_id; $user = new User_Model_User; $users = new User_Model_UserMapper; $users->find($userId, $user); $auth->getStorage()->write( $user ); } This seems to work well and I am able to use the object stored in the Zend_Auth storage within View Helpers without any problems. The problem that I seem to be having is when I try to use this within my Acl, below is a snippet from my Acl, as soon as it gets to the if($auth->hasIdentity()) { line I get the exception detailed further down. The $user->getUserLevel() is a methord within the User Model that allows me to convert the user_level_id that is stored in the database to a meaning full name. I am assuming that the auto loader sees these kind of methords and tries to load all the classes that would be required. When looking at the exception it appears to be struggling to find the class as it is stored in a module, I have the Auto Loader Name Space setup in my application.ini. Could anyone help with resolving this? class App_Controller_Plugin_Acl extends Zend_Controller_Plugin_Abstract { protected $_roleName; public function __construct() { $auth = Zend_Auth::getInstance(); if($auth->hasIdentity()) { $user = $auth->getIdentity(); $this->_roleName = strtolower($user->getUserLevel()); } else { $this->_roleName = 'guest'; } } } Fatal error: Uncaught exception 'Zend_Session_Exception' with message 'Zend_Session::start() - \Web\library\Zend\Loader.php(Line:146): Error #2 include_once() [&lt;a href='function.include'&gt;function.include&lt;/a&gt;]: Failed opening 'Menu\Model\UserLevel.php' for inclusion (include_path='\Web\application/../library;\Web\library;.;C:\php5\pear') Array' in \Web\library\Zend\Session.php:493 Stack trace: #0 \Web\library\Zend\Session\Namespace.php(143): Zend_Session::start(true) #1 \Web\library\Zend\Auth\Storage\Session.php(87): Zend_Session_Namespace-&gt;__construct('Zend_Auth') #2 \Web\library\Zend\Auth.php(91): Zend_Auth_Storage_Session-&gt;__construct() #3 \Web\library\Zend\A in \Web\library\Zend\Session.php on line 493 Thanks, Martin

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  • Why aren't min-width and max-width working as I expect?

    - by Nathan Long
    I'm trying to adjust a CSS page layout using min-width and max-width. To simplify the problem, I made this test page. I'm trying it out in the latest versions of Firefox and Chrome with the same results. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Testing min-width and max-width</title> <style type="text/css"> div{float: left; max-width: 400px; min-width: 200px;} div.a{background: orange;} div.b{background: gray;} </style> </head> <body> <div class="a"> (Giant block of filler text here) </div> <div class="b"> (Giant block of filler text here) </div> </body> </html> Here's what I expect to happen: With the browser maximized, the divs sit side by side, each 400px wide: their maximum width Shrink the browser window, and they both shrink to 200px: their minimum width Further shrinking the browser has no effect on them Here's what actually happens, starting at step 2: Shrink the browser window, and as soon as they can't sit side-by-side at their max width, the second div drops below the first Further shrinking the browser makes them get narrower and narrower, as small as I can make the window So here's are my questions: What does max-width mean if the element will sooner hop down in the layout than go lower than its maximum width? What does min-width mean if the element will happily get narrower than that if the browser window keeps shrinking? Is there any way to achieve what I want: have these elements sit side-by-side, happily shrinking until they reach 200px each, and only then adjust the layout so that the second one drops down? And of course... What am I doing wrong?

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  • How do I pass a variable number of parameters along with a callback function?

    - by Bungle
    I'm using a function to lazy-load the Sizzle selector engine (used by jQuery): var sizzle_loaded; // load the Sizzle script function load_sizzle(module_name) { var script; // load Sizzle script and set up 'onload' and 'onreadystatechange' event // handlers to ensure that external script is loaded before dependent // code is executed script = document.createElement('script'); script.src = 'sizzle.min.js'; script.onload = function() { sizzle_loaded = true; gather_content(module_name); }; script.onreadystatechange = function() { if ((script.readyState === 'loaded' || script.readyState === 'complete') && !sizzle_loaded) { sizzle_loaded = true; gather_content(module_name); } }; // append script to the document document.getElementsByTagName('head')[0].appendChild(script); } I set the onload and onreadystatechange event handlers, as well as the sizzle_loaded flag to call another function (gather_content()) as soon as Sizzle has loaded. All of this is needed to do this in a cross-browser way. Until now, my project only had to lazy-load Sizzle at one point in the script, so I was able to just hard-code the gather_content() function call into the load_sizzle() function. However, I now need to lazy-load Sizzle at two different points in the script, and call a different function either time once it's loaded. My first instinct was to modify the function to accept a callback function: var sizzle_loaded; // load the Sizzle script function load_sizzle(module_name, callback) { var script; // load Sizzle script and set up 'onload' and 'onreadystatechange' event // handlers to ensure that external script is loaded before dependent // code is executed script = document.createElement('script'); script.src = 'sizzle.min.js'; script.onload = function() { sizzle_loaded = true; callback(module_name); }; script.onreadystatechange = function() { if ((script.readyState === 'loaded' || script.readyState === 'complete') && !sizzle_loaded) { sizzle_loaded = true; callback(module_name); } }; // append script to the document document.getElementsByTagName('head')[0].appendChild(script); } Then, I could just call it like this: load_sizzle(module_name, gather_content); However, the other callback function that I need to use takes more parameters than gather_content() does. How can I modify my function so that I can specify a variable number of parameters, to be passed with the callback function? Or, am I going about this the wrong way? Ultimately, I just want to load Sizzle, then call any function that I need to (with any arguments that it needs) once it's done loading. Thanks for any help!

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  • How do I destruct data associated with an object after the object no longer exists?

    - by Phineas
    I'm creating a class (say, C) that associates data (say, D) with an object (say, O). When O is destructed, O will notify C that it soon will no longer exist :( ... Later, when C feels it is the right time, C will let go of what belonged to O, namely D. If D can be any type of object, what's the best way for C to be able to execute "delete D;"? And what if D is an array of objects? My solution is to have D derive from a base class that C has knowledge of. When the time comes, C calls delete on a pointer to the base class. I've also considered storing void pointers and calling delete, but I found out that's undefined behavior and doesn't call D's destructor. I considered that templates could be a novel solution, but I couldn't work that idea out. Here's what I have so far for C, minus some details: // This class is C in the above description. There may be many instances of C. class Context { public: // D will inherit from this class class Data { public: virtual ~Data() {} }; Context(); ~Context(); // Associates an owner (O) with its data (D) void add(const void* owner, Data* data); // O calls this when he knows its the end (O's destructor). // All instances of C are now aware that O is gone and its time to get rid // of all associated instances of D. static void purge (const void* owner); // This is called periodically in the application. It checks whether // O has called purge, and calls "delete D;" void refresh(); // Side note: sometimes O needs access to D Data *get (const void *owner); private: // Used for mapping owners (O) to data (D) std::map _data; }; // Here's an example of O class Mesh { public: ~Mesh() { Context::purge(this); } void init(Context& c) const { Data* data = new Data; // GL initialization here c.add(this, new Data); } void render(Context& c) const { Data* data = c.get(this); } private: // And here's an example of D struct Data : public Context::Data { ~Data() { glDeleteBuffers(1, &vbo); glDeleteTextures(1, &texture); } GLint vbo; GLint texture; }; }; P.S. If you're familiar with computer graphics and VR, I'm creating a class that separates an object's per-context data (e.g. OpenGL VBO IDs) from its per-application data (e.g. an array of vertices) and frees the per-context data at the appropriate time (when the matching rendering context is current).

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  • Should we denormalize database to improve performance?

    - by Groo
    We have a requirement to store 500 measurements per second, coming from several devices. Each measurement consists of a timestamp, a quantity type, and several vector values. Right now there is 8 vector values per measurement, and we may consider this number to be constant for needs of our prototype project. We are using HNibernate. Tests are done in SQLite (disk file db, not in-memory), but production will probably be MsSQL. Our Measurement entity class is the one that holds a single measurement, and looks like this: public class Measurement { public virtual Guid Id { get; private set; } public virtual Device Device { get; private set; } public virtual Timestamp Timestamp { get; private set; } public virtual IList<VectorValue> Vectors { get; private set; } } Vector values are stored in a separate table, so that each of them references its parent measurement through a foreign key. We have done a couple of things to ensure that generated SQL is (reasonably) efficient: we are using Guid.Comb for generating IDs, we are flushing around 500 items in a single transaction, ADO.Net batch size is set to 100 (I think SQLIte does not support batch updates? But it might be useful later). The problem Right now we can insert 150-200 measurements per second (which is not fast enough, although this is SQLite we are talking about). Looking at the generated SQL, we can see that in a single transaction we insert (as expected): 1 timestamp 1 measurement 8 vector values which means that we are actually doing 10x more single table inserts: 1500-2000 per second. If we placed everything (all 8 vector values and the timestamp) into the measurement table (adding 9 dedicated columns), it seems that we could increase our insert speed up to 10 times. Switching to SQL server will improve performance, but we would like to know if there might be a way to avoid unnecessary performance costs related to the way database is organized right now. [Edit] With in-memory SQLite I get around 350 items/sec (3500 single table inserts), which I believe is about as good as it gets with NHibernate (taking this post for reference: http://ayende.com/Blog/archive/2009/08/22/nhibernate-perf-tricks.aspx). But I might as well switch to SQL server and stop assuming things, right? I will update my post as soon as I test it.

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  • How safe is my safe rethrow?

    - by gustafc
    (Late edit: This question will hopefully be obsolete when Java 7 comes, because of the "final rethrow" feature which seems like it will be added.) Quite often, I find myself in situations looking like this: do some initialization try { do some work } catch any exception { undo initialization rethrow exception } In C# you can do it like this: InitializeStuff(); try { DoSomeWork(); } catch { UndoInitialize(); throw; } For Java, there's no good substitution, and since the proposal for improved exception handling was cut from Java 7, it looks like it'll take at best several years until we get something like it. Thus, I decided to roll my own: (Edit: Half a year later, final rethrow is back, or so it seems.) public final class Rethrow { private Rethrow() { throw new AssertionError("uninstantiable"); } /** Rethrows t if it is an unchecked exception. */ public static void unchecked(Throwable t) { if (t instanceof Error) throw (Error) t; if (t instanceof RuntimeException) throw (RuntimeException) t; } /** Rethrows t if it is an unchecked exception or an instance of E. */ public static <E extends Exception> void instanceOrUnchecked( Class<E> exceptionClass, Throwable t) throws E, Error, RuntimeException { Rethrow.unchecked(t); if (exceptionClass.isInstance(t)) throw exceptionClass.cast(t); } } Typical usage: public void doStuff() throws SomeException { initializeStuff(); try { doSomeWork(); } catch (Throwable t) { undoInitialize(); Rethrow.instanceOrUnchecked(SomeException.class, t); // We shouldn't get past the above line as only unchecked or // SomeException exceptions are thrown in the try block, but // we don't want to risk swallowing an error, so: throw new SomeException("Unexpected exception", t); } private void doSomeWork() throws SomeException { ... } } It's a bit wordy, catching Throwable is usually frowned upon, I'm not really happy at using reflection just to rethrow an exception, and I always feel a bit uneasy writing "this will not happen" comments, but in practice it works well (or seems to, at least). What I wonder is: Do I have any flaws in my rethrow helper methods? Some corner cases I've missed? (I know that the Throwable may have been caused by something so severe that my undoInitialize will fail, but that's OK.) Has someone already invented this? I looked at Commons Lang's ExceptionUtils but that does other things. Edit: finally is not the droid I'm looking for. I'm only interested to do stuff when an exception is thrown. Yes, I know catching Throwable is a big no-no, but I think it's the lesser evil here compared to having three catch clauses (for Error, RuntimeException and SomeException, respectively) with identical code. Note that I'm not trying to suppress any errors - the idea is that any exceptions thrown in the try block will continue to bubble up through the call stack as soon as I've rewinded a few things.

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  • ASP.NET MVC 2 AJAX dilemma: Lose Models concept or create unmanageable JavaScript

    - by Slightly Frustrated
    Hi, Ok, let's assume we are working with ASP.NET MVC 2 (latest and greatest preview) and we want to create AJAX user interface with jQuery. So what are our real options here? Option 1 - Pass Json from the Controller to the view, and then the view submits Json back to the controller. This means (in the order given): User opens some View (let's say - /Invoices/January) which has to visualize a list of data (e.g. <IEnumerable<X.Y.Z.Models.Invoice>>) Controller retrieves the Model from the repository (assuming we are using repository pattern). Controller creates a new instance of a class which we will serialize to Json. The reasaon we do this, is because the model may not be serializable (circular reference ftl) Controller populates the soon-to-be-serialized class with data Controller serializes the class to Json and passes it the view. User does some change and submits the 'form' The View submits back Json to the controller The Controller now must 'manually' validate the input, because the Json passed does not bind to a Model See, if our View is communicating to the controller via Json, we lose the Model validation, which IMHO is incredible disadvantage. In this case, forget about data annotations and stuff. Option 2 - Ok, the alternative of the first approach is to pass the Models to the Views, which is the default behavior in the template when you start a new project. We pass a strong typed model to the view The view renders the appropriate html and javascript, sticking to the model property names. This is important! The user submits the form. If we stick to the model names, when we .serialize() the form and submit it to the controller it will map to a model. There is no Json mapping. The submitted form directly binds to a strongly typed model, hence, we can use the model validation. E.g. we keep the business logic where it should be. Problem with this approach is, if we refactor some of the Models (change property names, types, etc), the javascript we wrote would become invalid. We will have to manually refactor the scripting and hope we don't miss something. There is no way you can test it either. Ok, the question is - how to write an AJAX front end, which keeps the business logic validation in the model (e.g. controller passes and receives a Model type), but in the same time doesn't screw up the javascript and html when we refactor the model?

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  • Access Denied Java FileWriter / FileInputStream

    - by Matt
    My program downloads a websites source code, modifies it, creates the file, and then reuploads it through the FTP. However, I receive the following error when trying to open the created file: java.io.FileNotFoundException: misc.html (Access is denied) at java.io.FileInputStream.open(Native Method) at java.io.FileInputStream.<init>(Unknown Source) at Manipulator.uploadSource(Manipulator.java:63) at Start.addPicture(Start.java:130) at Start$2.actionPerformed(Start.java:83) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Window.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) When I navigate to the folder directory and attempt to open "misc.html" with Notepad I receive Access is Denied. My code is fairly simple: File f = new File(page.sourceFileName); try { FileWriter out = new FileWriter(f); out.write(page.source); out.close(); } catch (IOException e) { e.printStackTrace(); } InputStream input = new FileInputStream(f); This is the vital excerpt from my program. I have copied this into a different test program and it works fine, I create a misc.html file and reopen it with both FileInputStream and manually. I would be worried about Administrator rights but the Test program works fine when I run it RIGHT after the problem program. I also have checked if the file exists and is a file with File methods and it is as well. Is this a result of me not closing a previous Input/Output properly? I've tried to check everything and I am fairly positive I close all streams as soon as they finish... Help! :)

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  • How does this Singleton-like web class persists session data, even though session is not updated in

    - by Micah Burnett
    Ok, I've got this singleton-like web class which uses session to maintain state. I initially thought I was going to have to manipulate the session variables on each "set" so that the new values were updated in the session. However I tried using it as-is, and somehow, it remembers state. For example, if run this code on one page: UserContext.Current.User.FirstName = "Micah"; And run this code in a different browser tab, FirstName is displayed correctly: Response.Write(UserContext.Current.User.FirstName); Can someone tell me (prove) how this data is getting persisted in the session? Here is the class: using System; using System.Collections.Generic; using System.Linq; using System.Web; public class UserContext { private UserContext() { } public static UserContext Current { get { if (System.Web.HttpContext.Current.Session["UserContext"] == null) { UserContext uc = new UserContext(); uc.User = new User(); System.Web.HttpContext.Current.Session["UserContext"] = uc; } return (UserContext)System.Web.HttpContext.Current.Session["UserContext"]; } } private string HospitalField; public string Hospital { get { return HospitalField; } set { HospitalField = value; ContractField = null; ModelType = null; } } private string ContractField; public string Contract { get { return ContractField; } set { ContractField = value; ModelType = string.Empty; } } private string ModelTypeField; public string ModelType { get { return ModelTypeField; } set { ModelTypeField = value; } } private User UserField; public User User { get { return UserField; } set { UserField = value; } } public void DoSomething() { } } public class User { public int UserId { get; set; } public string FirstName { get; set; } } I added this to a watch, and can see that the session variable is definitely being set somewhere: (UserContext)System.Web.HttpContext.Current.Session["UserContext"]; As soon as a setter is called the Session var is immediately updated: set { HospitalField = value; //<--- here ContractField = null; ModelType = null; }

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  • iPhone App is leaking memory; Instruments and Clang cannot find the leak

    - by Norbert
    Hi, i've developed an iPhone program which is kind of an image manipulation program: The user get an UIImagePickerController and selects an image. Then the program does some heavy calculating in a new thread (for responsiveness of the application). The thread has, of course, its own autorelease pool. When calculation is done, the seperated thread signals the main thread that the result can be presented. The app creates a new view controller, pushes it onto the navigation controller. In short: UIImagePickerController new thread (autorelease pool) does some heavy calculation with image data signal to main thread that it's done main thread creates view controller and pushes it onto navigation controller view controller presents image result My program works well, but if I dismiss the navigation controller's top view controller by tapping on the back button and repeat the whole process several times, my app crashes. But only on the device! Instruments cannot find any leaks (except for some minor ones which I don't feel responsible for: thread creation, NSCFString; overall about 10 kB). Even Clang static analyzer tells me that my could seems to be all right. I know that the UIImage class can cache images and objects returned from convenience methods get freed only whet their autorelease pool gets drained. But most of the time I work with CGImageRef and I use UIImage' alloc, init & release methods to free memory as soon as possible. Currently, I don't know how to isolate the problem. How would you approach this problem? Crash Log: Incident Identifier: F4C202C9-1338-48FC-80AD-46248E6C7154 CrashReporter Key: bb6f526d8b9bb680f25ea8e93bb071566ccf1776 OS Version: iPhone OS 3.1.1 (7C145) Date: 2009-09-26 14:18:57 +0200 Free pages: 372 Wired pages: 7754 Purgeable pages: 0 Largest process: _MY_APP_ Processes Name UUID Count resident pages _MY_APP_ <032690e5a9b396058418d183480a9ab3> 17766 (jettisoned) (active) debugserver <ec29691560aa0e2994f82f822181bffd> 107 syslog_relay <21e13fa2b777218bdb93982e23fb65d3> 62 notification_pro <8a7725017106a28b545fd13ed58bf98c> 64 notification_pro <8a7725017106a28b545fd13ed58bf98c> 64 afcd <98b45027fbb1350977bf1ca313dee527> 65 mediaserverd <eb8fe997a752407bea573cd3adf568d3> 319 ptpd <b17af9cf6c4ad16a557d6377378e8a1e> 142 syslogd <ec8a5bc4483638539fa1266363dee8b8> 68 BTServer <1bb74831f93b1d07c48fb46cc31c15da> 119 apsd <a639ba83e666cc1d539223923ce59581> 165 notifyd <2ed3a1166da84d8d8868e64d549cae9d> 101 CommCenter <f4239480a623fb1c35fa6c725f75b166> 161 SpringBoard <8919df8091fdfab94d9ae05f513c0ce5> 2681 (active) accessoryd <b66bcf6e77c3ee740c6a017f54226200> 90 configd <41e9d763e71dc0eda19b0afec1daee1d> 275 fairplayd <cdce5393153c3d69d23c05de1d492bd4> 108 mDNSResponder <f3ef7a6b24d4f203ed147f476385ec53> 103 lockdownd <6543492543ad16ff0707a46e512944ff> 297 launchd <73ce695fee09fc37dd70b1378af1c818> 71 **End**

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  • jquery ui autocomplete does't close options menu if there is no focus when ajax returns

    - by Uri
    I'm using jquery ui autocomplete widget with ajax, and on noticed the following problem. Background: In order for the user to be able to focus on the autocomplete and get the options without typing anything, I use the focus event: autoComp.focus(function() { $(this).autocomplete("search", "");} However this produces the following effect: when the user clicks, an ajax request is being sent. While waiting for the response, the user then clicks elsewhere and the autocomplete is blurred. But as soon as the response returns, the options menu pops out, even though the autocomplete has no focus. In order to make it go away the user has to click once inside, and again outside the autocomplete, which is a bit annoying. any ideas how I prevent this? EDIT: I solved this in a very ugly way by building another mediator function that knows the element's ID, and this function calls the ajax function with the ID, which on success check the focus of the element, and returns null if it's not focused. It's pretty ugly and I'm still looking for alternatives. EDIT#2: Tried to do as Wlliam suggested, still doesn't work.. the xhr is undefined when blurring. Some kind of a problem with the this keyword, maybe it has different meanings if I write the getTags function outside of the autocomplete? this.autocomplete = $('.tab#'+this.id+' #tags').autocomplete({ minLength: 0, autoFocus: true, source: getTags, select: function(e, obj) { tab_id = $(this).parents('.tab').attr('id'); tabs[tab_id].addTag(obj.item.label, obj.item.id, false); $(this).blur(); // This is done so that the options menu won't pop up again. return false; // This is done so that the value will not stay in the input box after selection. }, open: function() {}, close: function() {} }); $('.tab#'+this.id+' #tags').focus(function() { $(this).autocomplete("search", ""); }); $('.tab#'+this.id+' #tags').blur(function() { console.log('blurring'); var xhr = $(this).data('xhr'); // This comes out undefined... :( if (xhr) { xhr.abort(); }; $(this).removeClass('ui-autocomplete-loading'); }); and this is the getTags function copied to the source keyword: function getTags(request, response) { console.log('Getting tags.'); $(this).data('xhr', $.ajax({ url: '/rpc', dataType: 'json', data: { action: 'GetLabels', arg0: JSON.stringify(request.term) }, success: function(data) { console.log('Tags arrived:'); tags = []; for (i in data) { a = {} a.id = data[i]['key']; a.label = data[i]['name']; tags.push(a); } response(tags); } })); console.log($(this).data('xhr')); }

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  • How to Sync CI (Hudson) Activity into an existing automated Build Process (phing, svn)?

    - by maraspin
    OUR CURRENT BUILD PROCESS We're a small team of developers (2 to 4 people depending on project) who currently use Phing to deploy code to a staging environment, before going live. We keep our code in a SVN repo, where the trunk holds current active development and, at certain times, we do make branches that we test and then (if successful), tag and export to the staging env. If everything goes well there too, we finally deploy'em in production servers. Actions are highly automated, but always triggered by human intervention. THE DOUBT We'd now like to introduce Continuous Integration (with Hudson) in the process; unfortunately we have a few doubts about activity syncing, since we're afraid that CI could somewhat interfere with our build process and cause certain problems. Considering that an automated CI cycle has a certain frequency of automatically executed actions, we see 2 possible cases for "integration", each with its own problems: Case A: each CI cycle produces a new branch with its own name; we do use such a name to manually (through phing as it happens now) export the code from the SVN to the staging env. The problem I see here is that (unless specific countermeasures are taken - IE deletion) the number of branches we have can easily grow out of control (let's suppose we commit often, so that we have a fresh new build/branch every N minutes). Case B: each CI cycle creates a new branch named 'current', which is then tagged with a unique name only when we manually decide to export it to staging; the current branch, at any case is then deleted, as soon as the next CI cycle starts up. The problem we see here is that a new cycle could kick in while someone is tagging/exporting the 'current' branch to staging thus creating an inconsistent build (but maybe here I'm just too pessimist, since I confess I don't know whether SVN offers some built-in protection against this). With all this being said, I was wondering if anyone with similar experiences could be so kind to give us some hints on the subject, since none of the approaches depicted above looks completely satisfing to us. Is there something important we just completely left off in the overall picture? Thanks for your attention & (in advance) for your help!

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  • Parallel Task Library WaitAny Design

    - by colithium
    I've just begun to explore the PTL and have a design question. My Scenario: I have a list of URLs that each refer to an image. I want each image to be downloaded in parallel. As soon as at least one image is downloaded, I want to execute a method that does something with the downloaded image. That method should NOT be parallelized -- it should be serial. I think the following will work but I'm not sure if this is the right way to do it. Because I have separate classes for collecting the images and for doing "something" with the collected images, I end up passing around an array of Tasks which seems wrong since it exposes the inner workings of how images are retrieved. But I don't know a way around it. In reality there is more to both of these methods but that's not important for this. Just know that they really shouldn't be lumped into one large method that both retrieves and does something with the image. Task<Image>[] downloadTasks = collector.RetrieveImages(listOfURLs); for (int i = 0; i < listOfURLs.Count; i++) { //Wait for any of the remaining downloads to complete int completedIndex = Task<Image>.WaitAny(downloadTasks); Image completedImage = downloadTasks[completedIndex].Result; //Now do something with the image (this "something" must happen serially) } /////////////////////////////////////////////////// public Task<Image>[] RetrieveImages(List<string> urls) { Task<Image>[] tasks = new Task<Image>[urls.Count]; int index = 0; foreach (string url in urls) { string lambdaVar = url; //Required... Bleh tasks[index] = Task<Image>.Factory.StartNew(() => { using (WebClient client = new WebClient()) { //TODO: Replace with live image locations string fileName = String.Format("{0}.png", i); client.DownloadFile(lambdaVar, Path.Combine(Application.StartupPath, fileName)); } return Image.FromFile(Path.Combine(Application.StartupPath, fileName)); }, TaskCreationOptions.LongRunning | TaskCreationOptions.AttachedToParent); index++; } return tasks; }

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  • Unable to add item to dataset in Linq to SQL

    - by Mike B
    I am having an issue adding an item to my dataset in Linq to SQL. I am using the exact same method in other tables with no problem. I suspect I know the problem but cannot find an answer (I also suspect all i really need is the right search term for Google). Please keep in mind this is a learning project (Although it is in use in a business) I have posted my code and datacontext below. What I am doing is: Create a view model (Relevant bits are shown) and a simple wpf window that allows editing of 3 properties that are bound to the category object. Category is from the datacontext. Edit works fine but add does not. If I check GetChangeSet() just before the db.submitChanges() call there are no adds, edits or deletes. I suspect an issue with the fact that a Category added without a Subcategory would be an orphan but I cannot seem to find the solution. Command code to open window: CategoryViewModel vm = new CategoryViewModel(); AddEditCategoryWindow window = new AddEditCategoryWindow(vm); window.ShowDialog(); ViewModel relevant stuff: public class CategoryViewModel : ViewModelBase { public Category category { get; set; } // Constructor used to Edit a Category public CategoryViewModel(Int16 categoryID) { db = new OITaskManagerDataContext(); category = QueryCategory(categoryID); } // Constructor used to Add a Category public CategoryViewModel() { db = new OITaskManagerDataContext(); category = new Category(); } } The code for saving changes: // Don't close window unless all controls are validated if (!vm.IsValid(this)) return; var changes = vm.db.GetChangeSet(); // DEBUG try { vm.db.SubmitChanges(ConflictMode.ContinueOnConflict); } catch (ChangeConflictException) { vm.db.ChangeConflicts.ResolveAll(RefreshMode.KeepChanges); vm.db.SubmitChanges(); } The Xaml (Edited fror brevity): <TextBox Text="{Binding category.CatName, Mode=TwoWay, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" /> <TextBox Text="{Binding category.CatDescription, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" /> <CheckBox IsChecked="{Binding category.CatIsInactive, Mode=TwoWay}" /> IssCategory in the Issues table is the old, text based category. This field is no longer used and will be removed from the database as soon as this is working and pushed live.

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  • DCVS + hosting for a startup commercial multiplatform phone app

    - by AG
    I'm in lean startup mode, working on a simple phone app that will be published initially as a iThingy app and an Android app with, possibly, Blackberry and Symbian versions to follow. I'm about to go from no repository to needing a central repository that up to 4 very part-time resources will be sharing. Two of us have no version control background, one has used Subversion, and I've used most of the major centralized VCS systems. I'm not going to be pushing the technical limitations of any VCS for a long time; I'm sure that any of the major systems would work fine. And the hosting accounts I've looked at seem reasonable. So I'm really focussed on minimizing the downside risks. That is, I'd like to find a stable setup that is easy to learn in general, easy to use from Windows/Eclipse, and won't paint me into any obvious corners for the next 12 months or so. A quick search of the web had led me to consider the following pairs of DVCS and hosting service, with what I think I'm hearing as their strengths and weaknesses (for my purposes): Bazaar/Launchpad -- My initial choice since I need to get more familiar with this pair for the Google Summer of Code mentoring I'm doing. But, whatever the technical merits, a non-starter for me because they are purely open source, no private repositories plans to purchase that I can see. Git/GitHub -- Git: Fast, light, ultimately flexible, but relatively less Windows friendly, Eclipse plugin (eGit) available but relatively young, GitHub: widely used, pricing is fine Mercurial/BitBucket -- Mercurial: a little less flexible, a little more Windows friendly, Eclipse plugin seems a bit more mature, BitBucket: widely used, pricing is fine, includes a wiki and an issue tracker that we might be able to use instead of something like BaseCamp, at least for a while. Mercurial/BitBucket seem like the winning pair so far for my particular situation; at least two of us are definitely going to be working mostly from Eclipse on Windows and reducing my own learning curve is a priority. ;-) But I have two specific questions: 1) Am I wrong about Bazaar/Launchpad and is there a viable, secure way to use them for proprietary code? 2) Any reason to think that the Mecurial/Bitbucket pair will end up being a headache for my Mac developer, soon, or for Blackberry or Symbian developers a little later? ag

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  • Postgres Stored procedure using iBatis

    - by Om Yadav
    --- The error occurred while applying a parameter map. --- Check the newSubs-InlineParameterMap. --- Check the statement (query failed). --- Cause: org.postgresql.util.PSQLException: ERROR: wrong record type supplied in RETURN NEXT Where: PL/pgSQL function "getnewsubs" line 34 at return next the function detail is as below.... CREATE OR REPLACE FUNCTION getnewsubs(timestamp without time zone, timestamp without time zone, integer) RETURNS SETOF record AS $BODY$declare v_fromdt alias for $1; v_todt alias for $2; v_domno alias for $3; v_cursor refcursor; v_rec record; v_cpno bigint; v_actno int; v_actname varchar(50); v_actid varchar(100); v_cpntypeid varchar(100); v_mrp double precision; v_domname varchar(100); v_usedt timestamp without time zone; v_expirydt timestamp without time zone; v_createdt timestamp without time zone; v_ctno int; v_phone varchar; begin open v_cursor for select cpno,c.actno,usedt from cpnusage c inner join account s on s.actno=c.actno where usedt = $1 and usedt < $2 and validdomstat(s.domno,v_domno) order by c.usedt; fetch v_cursor into v_cpno,v_actno,v_usedt; while found loop if isactivation(v_cpno,v_actno,v_usedt) IS TRUE then select into v_actno,v_actname,v_actid,v_cpntypeid,v_mrp,v_domname,v_ctno,v_cpno,v_usedt,v_expirydt,v_createdt,v_phone a.actno,a.actname as name,a.actid as actid,c.descr as cpntypeid,l.mrp as mrp,s.domname as domname,c.ctno as ctno,b.cpno,b.usedt,b.expirydt,d.createdt,a.phone from account a inner join cpnusage b on a.actno=b.actno inner join cpn d on b.cpno=d.cpno inner join cpntype c on d.ctno=c.ctno inner join ssgdom s on a.domno=s.domno left join price_class l ON l.price_class_id=b.price_class_id where validdomstat(a.domno,v_domno) and b.cpno=v_cpno and b.actno=v_actno; select into v_rec v_actno,v_actname,v_actid,v_cpntypeid,v_mrp,v_domname,v_ctno,v_cpno,v_usedt,v_expirydt,v_createdt,v_phone; return next v_rec; end if; fetch v_cursor into v_cpno,v_actno,v_usedt; end loop; return ; end;$BODY$ LANGUAGE 'plpgsql' VOLATILE; ALTER FUNCTION getnewsubs(timestamp without time zone, timestamp without time zone, integer) OWNER TO radius If i am running the function from the console it is running fine and giving me the correct response. But when using through java causing the above error. Can ay body help in it..Its very urgent. Please response as soon as possible. Thanks in advance.

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  • Datagrid selects the wrong custom cell in my datagrid...

    - by Markus
    Hi everybody, I am working on a problem since a week soon, but I still couldn't make it work as expected. I have a DataGrid which has HBox with a CheckBox an a Label as itemRenderer (see Code below). When I tap in to the Cell the standard itemEditor pops up and lets you enter the content of the label. Thats the standard behavior. I works fine except for 2 problems: If I enter to much text, the horizontal srollbar pops up, and the cell is filled with that scrollbar. As you see I tried to set the horizontalScrollPolicy to off, but that doesnt work at all... I tried to do that for all the different elements, but the failure is still existent. When I have filled more than one row, there is an other mistake happening. If I tap on a row, the datagrid selects the one below that row. That's only if one line is already selected. If I tap outside the datagrid and then, tap at any row the itemEditor of the right row will show up... Is there anything now wright in the setup of my set data method? __ package components { import mx.containers.HBox; import mx.controls.CheckBox; import mx.controls.Label; public class ChoiceRenderer extends HBox { private var correctAnswer:CheckBox; private var choiceLabel:Label; public function ChoiceRenderer() { super(); paint(); } private function paint():void{ percentHeight = 100; percentWidth = 100; setStyle("horizontalScrollPolicy", "off"); super.setStyle("horizontalScrollPolicy", "off"); correctAnswer = new CheckBox; correctAnswer.setStyle("horizontalScrollPolicy", "off"); addChild(correctAnswer); choiceLabel = new Label; choiceLabel.setStyle("horizontalScrollPolicy", "off"); addChild(choiceLabel); } override public function set data(xmldata:Object):void{ if(xmldata.name() == "BackSide"){ var xmlText:Object = xmldata.TextElements.TextElement.(@position == position)[0]; super.data = xmlText; choiceLabel.text = xmlText.toString(); correctAnswer.selected = xmlText.@correct_answer; } } } Thanks in advance! Markus

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  • I have to select the checkbox two times to check/uncheck in jTable

    - by 117526709403775781607
    I have a jTable code i intend to use, but the problem with it is that when i click on the checkbox once it doesn't select/deselect it, instead i have to click twice. But if i select any other cell in the row except the one containing the checkbox the purpose is solved. HERE IS MY CODE : public class TableSelectionTest extends JFrame implements ListSelectionListener { private final int COLUMN_COUNT = 5; private TblModel model; public TableSelectionTest() { initialize(); setDefaultCloseOperation(EXIT_ON_CLOSE); pack(); } private void initialize() { List data = new ArrayList(); for (int i = 0; i < 10; i++) { Object record[] = new Object[COLUMN_COUNT]; record[0] = Boolean.FALSE; for (int j = 1; j < COLUMN_COUNT; j++) { record[j] = new Integer(j); } data.add(record); } model = new TblModel(data); JTable table = new JTable(model); table.getSelectionModel().setSelectionMode(ListSelectionModel.SINGLE_SELECTION); table.getSelectionModel().addListSelectionListener (this); JScrollPane scroll = new JScrollPane(table); getContentPane().add(scroll, BorderLayout.CENTER); } public static void main(String[] args) { TableSelectionTest f = new TableSelectionTest(); f.show(); } class TblModel extends AbstractTableModel { private List data; public TblModel(List data) { this.data = data; } public int getColumnCount() { return COLUMN_COUNT; } public int getRowCount() { return data == null ? 0 : data.size(); } public void setValueAt(Object value, int rowIndex, int columnIndex) { getRecord(rowIndex)[columnIndex] = value; super.fireTableCellUpdated(rowIndex, columnIndex); } public Object getValueAt(int rowIndex, int columnIndex) { return getRecord(rowIndex)[columnIndex]; } public boolean isCellEditable(int rowIndex, int columnIndex) { if(columnIndex == 0) return true; else return false; } public Class getColumnClass(int columnIndex) { if (data == null || data.size() == 0) { return Object.class; } Object o = getValueAt(0, columnIndex); return o == null ? Object.class : o.getClass(); } private Object[] getRecord(int rowIndex) { return (Object[]) data.get(rowIndex); } } public void valueChanged(ListSelectionEvent e) { if (!e.getValueIsAdjusting()) { ListSelectionModel lsm = (ListSelectionModel) e.getSource(); int index = lsm.getMinSelectionIndex(); if(model.getRecord(index)[0] == Boolean.FALSE) model.setValueAt(Boolean.TRUE, index, 0); else if(model.getRecord(index)[0] == Boolean.TRUE) model.setValueAt(Boolean.FALSE, index, 0); } } } Please reply soon as it is bugging me a lot Thank you in advance :)

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  • how get fully result from Asynchronism communication?

    - by rima
    Hi all refer to these post : here1 and here2 at last I solve my problem by build a asynchronous solution,and it work well!!! but there is a problem that i face with it,now my code is like this: class MyProcessStarter { private Process process; private StreamWriter myStreamWriter; private static StringBuilder shellOutput = null; public String GetShellOutput { get { return shellOutput.ToString(); }} public MyProcessStarter(){ shellOutput = new StringBuilder(""); process = new Process(); process.StartInfo.FileName = "sqlplus"; process.StartInfo.UseShellExecute = false; process.StartInfo.CreateNoWindow = true; process.OutputDataReceived += new DataReceivedEventHandler(ShellOutputHandler); process.StartInfo.RedirectStandardInput = true; process.StartInfo.RedirectStandardOutput = true; //process.StartInfo.RedirectStandardError = true; process.Start(); myStreamWriter = process.StandardInput; process.BeginOutputReadLine(); } private static void ShellOutputHandler(object sendingProcess,DataReceivedEventArgs outLine) { if (!String.IsNullOrEmpty(outLine.Data)) shellOutput.Append(Environment.NewLine + outLine.Data); } public void closeConnection() { myStreamWriter.Close(); process.WaitForExit(); process.Close(); } public void RunCommand(string arguments) { myStreamWriter.WriteLine(arguments); myStreamWriter.Flush(); process.WaitForExit(100); Console.WriteLine(shellOutput); Console.WriteLine("============="+Environment.NewLine); process.WaitForExit(2000); Console.WriteLine(shellOutput); } } and my input is like this: myProcesStarter.RunCommand("myusername/mypassword"); Console.writeline(myProcesStarter.GetShellOutput); but take a look at my out put: SQL*Plus: Release 11.1.0.6.0 - Production on Thu May 20 11:57:38 2010 Copyright (c) 1982, 2007, Oracle. All rights reserved. ============= SQL*Plus: Release 11.1.0.6.0 - Production on Thu May 20 11:57:38 2010 Copyright (c) 1982, 2007, Oracle. All rights reserved. Enter user-name: Connected to: Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production With the Partitioning, OLAP, Data Mining and Real Application Testing options as u see the output for run a function is not same in different time!So now would you do me a faver and help me that how I can wait until all the output done in other mean how I can customize my process to wait until output finishing ?? because I want to write a sqlcompiler so I need the exact output of shell. plz help me soon.thanxxxxxxxxxxxx :X

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  • Embedded "Smart" character LCD driver. Is this a good idea?

    - by chris12892
    I have an embedded project that I am working on, and I am currently coding the character LCD driver. At the moment, the LCD driver only supports "dumb" writing. For example, let's say line 1 has some text on it, and I make a call to the function that writes to the line. The function will simply seek to the beginning of the line and write the text (plus enough whitespace to erase whatever was last written). This is well and good, but I get the feeling it is horribly inefficient sometimes, since some lines are simply: "Some-reading: some-Value" Rather than "brute force" replacing the entire line, I wanted to develop some code that would figure out the best way to update the information on the LCD. (just as background, it takes 2 bytes to seek to any char position. I can then begin writing the string) My idea was to first have a loop. This loop would compare the input to the last write, and in doing so, it would cover two things: A: Collect all the differences between the last write and the input. For every contiguous segment (be it same or different) add two bytes to the byte count. This is referenced in B to determine if we are wasting serial bandwidth. B: The loop would determine if this is really a smart thing to do. If we end up using more bytes to update the line than to "brute force" the line, then we should just return and let the brute force method take over. We should exit the smart write function as soon as this condition is met to avoid wasting time. The next part of the function would take all the differences, seek to the required char on the LCD, and write them. Thus, if we have a string like this already on the LCD: "Current Temp: 80F" and we want to update it to "Current Temp: 79F" The function will go through and see that it would take less bandwidth to simply seek to the "8" and write "79". The "7" will cover the "8" and the "9" will cover the "0". That way, we don't waste time writing out the entire string. Does this seem like a practical idea?

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  • JSF 2.0: Preserving component state across multiple views

    - by tlind
    The web application I am developing using MyFaces 2.0.3 / PrimeFaces 2.2RC2 is divided into a content and a navigation area. In the navigation area, which is included into multiple pages using templating (i.e. <ui:define>), there are some widgets (e.g. a navigation tree, collapsible panels etc.) of which I want to preserve the component state across views. For example, let's say I am on the home page. When I navigate to a product details page by clicking on a product in the navigation tree, my Java code triggers a redirect using navigationHandler.handleNavigation(context, null, "/detailspage.jsf?faces-redirect=true") Another way of getting to that details page would be by directly clicking on a product teaser that is shown on the home page. The corresponding <h:link> would lead us to the details page. In both cases, the expansion state of my navigation tree (a PrimeFaces tree component) and my collapsible panels is lost. I understand this is because the redirect / h:link results in the creation of a new view. What is the best way of dealing with this? I am already using MyFaces Orchestra in my project along with its conversation scope, but I am not sure if this is of any help here (since I'd have to bind the expansion/collapsed state of the widgets to a backing bean... but as far as I know, this is not possible). Is there a way of telling JSF which component states to propagate to the next view, assuming that the same component exists in that view? I guess I could need a pointer into the right direction here. Thanks! Update 1: I just tried binding the panels and the tree to a session-scoped bean, but this seems to have no effect. Also, I guess I would have to bind all child components (if any) manually, so this doesn't seem like the way to go. Update 2: Binding UI components to non-request scoped beans is not a good idea (see link I posted in a comment below). If there is no easier approach, I might have to proceed as follows: When a panel is collapsed or the tree is expanded, save the current state in a session-scoped backing bean (!= the UI component itself) The components' states are stored in a map. The map key is the component's (hopefully) unique, relative ID. I cannot use the whole absolute component path here, since the IDs of the parent naming containers might change if the view changes, assuming these IDs are generated programmatically. As soon as a new view gets constructed, retrieve the components' states from the map and apply them to the components. For example, in case of the panels, I can set the collapsed attribute to a value retrieved from my session-scoped backing bean.

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  • How would you implement this "WorkerChain" functionality in .NET?

    - by Dan Tao
    Sorry for the vague question title -- not sure how to encapsulate what I'm asking below succinctly. (If someone with editing privileges can think of a more descriptive title, feel free to change it.) The behavior I need is this. I am envisioning a worker class that accepts a single delegate task in its constructor (for simplicity, I would make it immutable -- no more tasks can be added after instantiation). I'll call this task T. The class should have a simple method, something like GetToWork, that will exhibit this behavior: If the worker is not currently running T, then it will start doing so right now. If the worker is currently running T, then once it is finished, it will start T again immediately. GetToWork can be called any number of times while the worker is running T; the simple rule is that, during any execution of T, if GetToWork was called at least once, T will run again upon completion (and then if GetToWork is called while T is running that time, it will repeat itself again, etc.). Now, this is pretty straightforward with a boolean switch. But this class needs to be thread-safe, by which I mean, steps 1 and 2 above need to comprise atomic operations (at least I think they do). There is an added layer of complexity. I have need of a "worker chain" class that will consist of many of these workers linked together. As soon as the first worker completes, it essentially calls GetToWork on the worker after it; meanwhile, if its own GetToWork has been called, it restarts itself as well. Logically calling GetToWork on the chain is essentially the same as calling GetToWork on the first worker in the chain (I would fully intend that the chain's workers not be publicly accessible). One way to imagine how this hypothetical "worker chain" would behave is by comparing it to a team in a relay race. Suppose there are four runners, W1 through W4, and let the chain be called C. If I call C.StartWork(), what should happen is this: If W1 is at his starting point (i.e., doing nothing), he will start running towards W2. If W1 is already running towards W2 (i.e., executing his task), then once he reaches W2, he will signal to W2 to get started, immediately return to his starting point and, since StartWork has been called, start running towards W2 again. When W1 reaches W2's starting point, he'll immediately return to his own starting point. If W2 is just sitting around, he'll start running immediately towards W3. If W2 is already off running towards W3, then W2 will simply go again once he's reached W3 and returned to his starting point. The above is probably a little convoluted and written out poorly. But hopefully you get the basic idea. Obviously, these workers will be running on their own threads. Also, I guess it's possible this functionality already exists somewhere? If that's the case, definitely let me know!

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  • Instance caching in Objective C

    - by zoul
    Hello! I want to cache the instances of a certain class. The class keeps a dictionary of all its instances and when somebody requests a new instance, the class tries to satisfy the request from the cache first. There is a small problem with memory management though: The dictionary cache retains the inserted objects, so that they never get deallocated. I do want them to get deallocated, so that I had to overload the release method and when the retain count drops to one, I can remove the instance from cache and let it get deallocated. This works, but I am not comfortable mucking around the release method and find the solution overly complicated. I thought I could use some hashing class that does not retain the objects it stores. Is there such? The idea is that when the last user of a certain instance releases it, the instance would automatically disappear from the cache. NSHashTable seems to be what I am looking for, but the documentation talks about “supporting weak relationships in a garbage-collected environment.” Does it also work without garbage collection? Clarification: I cannot afford to keep the instances in memory unless somebody really needs them, that is why I want to purge the instance from the cache when the last “real” user releases it. Better solution: This was on the iPhone, I wanted to cache some textures and on the other hand I wanted to free them from memory as soon as the last real holder released them. The easier way to code this is through another class (let’s call it TextureManager). This class manages the texture instances and caches them, so that subsequent calls for texture with the same name are served from the cache. There is no need to purge the cache immediately as the last user releases the texture. We can simply keep the texture cached in memory and when the device gets short on memory, we receive the low memory warning and can purge the cache. This is a better solution, because the caching stuff does not pollute the Texture class, we do not have to mess with release and there is even a higher chance for cache hits. The TextureManager can be abstracted into a ResourceManager, so that it can cache other data, not only textures.

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  • Persistent (purely functional) Red-Black trees on disk performance

    - by Waneck
    I'm studying the best data structures to implement a simple open-source object temporal database, and currently I'm very fond of using Persistent Red-Black trees to do it. My main reasons for using persistent data structures is first of all to minimize the use of locks, so the database can be as parallel as possible. Also it will be easier to implement ACID transactions and even being able to abstract the database to work in parallel on a cluster of some kind. The great thing of this approach is that it makes possible implementing temporal databases almost for free. And this is something quite nice to have, specially for web and for data analysis (e.g. trends). All of this is very cool, but I'm a little suspicious about the overall performance of using a persistent data structure on disk. Even though there are some very fast disks available today, and all writes can be done asynchronously, so a response is always immediate, I don't want to build all application under a false premise, only to realize it isn't really a good way to do it. Here's my line of thought: - Since all writes are done asynchronously, and using a persistent data structure will enable not to invalidate the previous - and currently valid - structure, the write time isn't really a bottleneck. - There are some literature on structures like this that are exactly for disk usage. But it seems to me that these techniques will add more read overhead to achieve faster writes. But I think that exactly the opposite is preferable. Also many of these techniques really do end up with a multi-versioned trees, but they aren't strictly immutable, which is something very crucial to justify the persistent overhead. - I know there still will have to be some kind of locking when appending values to the database, and I also know there should be a good garbage collecting logic if not all versions are to be maintained (otherwise the file size will surely rise dramatically). Also a delta compression system could be thought about. - Of all search trees structures, I really think Red-Blacks are the most close to what I need, since they offer the least number of rotations. But there are some possible pitfalls along the way: - Asynchronous writes -could- affect applications that need the data in real time. But I don't think that is the case with web applications, most of the time. Also when real-time data is needed, another solutions could be devised, like a check-in/check-out system of specific data that will need to be worked on a more real-time manner. - Also they could lead to some commit conflicts, though I fail to think of a good example of when it could happen. Also commit conflicts can occur in normal RDBMS, if two threads are working with the same data, right? - The overhead of having an immutable interface like this will grow exponentially and everything is doomed to fail soon, so this all is a bad idea. Any thoughts? Thanks! edit: There seems to be a misunderstanding of what a persistent data structure is: http://en.wikipedia.org/wiki/Persistent_data_structure

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  • base64-Encoding breaks smime-encrypted emaildata

    - by Streuner
    I'm using Mime::Lite to create and send E-Mails. Now I need to add support for S/Mime-encryption and finally could encrypt my E-Mail (the only Perllib I could install seems broken, so I'm using a systemcall and openssl smime), but when I try to create a mime-object with it, the E-Mail will be broken as soon as I set the Content-Transfer-Encoding to base64. To make it even more curious, it happens only if I set it via $myMessage->attr. If I'm using the constructor -new everything is fine, besides a little warning which I suppress by using MIME::Lite->quiet(1); Is it a bug or my fault? Here are the two ways how I create the mime-object. Setting the Content-Transfer-Encoding via construtor and suppress the warning: MIME::Lite->quiet(1); my $msgEncr = MIME::Lite->new(From =>'[email protected]', To => '[email protected]', Subject => 'SMIME Test', Data => $myEncryptedMessage, 'Content-Transfer-Encoding' => 'base64'); $msgEncr->attr('Content-Disposition' => 'attachment'); $msgEncr->attr('Content-Disposition.filename' => 'smime.p7m'); $msgEncr->attr('Content-Type' => 'application/x-pkcs7-mime'); $msgEncr->attr('Content-Type.smime-type' => 'enveloped-data'); $msgEncr->attr('Content-Type.name' => 'smime.p7m'); $msgEncr->send; MIME::Lite->quiet(0); Setting the Content-Transfer-Encoding via $myMessage->attr which breaks the encrypted Data, but won't cause a warning: my $msgEncr = MIME::Lite->new(From => '[email protected]', To => '[email protected]', Subject => 'SMIME Test', Data => $myEncryptedMessage); $msgEncr->attr('Content-Disposition' => 'attachment'); $msgEncr->attr('Content-Disposition.filename' => 'smime.p7m'); $msgEncr->attr('Content-Type' => 'application/x-pkcs7-mime'); $msgEncr->attr('Content-Type.smime-type' => 'enveloped-data'); $msgEncr->attr('Content-Type.name' => 'smime.p7m'); $msgEncr->attr('Content-Transfer-Encoding' => 'base64'); $msgEncr->send; I just don't get why my message is broken when I'm using the attribute-setter. Thanks in advance for your help! Besides that i'm unable to attach any file to this E-Mail without breaking the encrypted message again.

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