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  • What is Ruby's analog to Python Metaclasses?

    - by Sean Copenhaver
    Python has the idea of metaclasses that, if I understand correctly, allow you to modify an object of a class at the moment of construction. You are not modifying the class, but instead the object that is to be created then initialized. Python (at least as of 3.0 I believe) also has the idea of class decorators. Again if I understand correctly, class decorators allow the modifying of the class definition at the moment it is being declared. Now I believe there is an equivalent feature or features to the class decorator in Ruby, but I'm currently unaware of something equivalent to metaclasses. I'm sure you can easily pump any Ruby object through some functions and do what you will to it, but is there a feature in the language that sets that up like metaclasses do? So again, Does Ruby have something similar to Python's metaclasses? Edit I was off on the metaclasses for Python. A metaclass and a class decorator do very similar things it appears. They both modify the class when it is defined but in different manners. Hopefully a Python guru will come in and explain better on these features in Python. But a class or the parent of a class can implement a __new__(cls[,..]) function that does customize the construction of the object before it is initialized with __init__(self[,..]).

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  • How to read LARGE Sqlite file to be copied into Android emulator, or device from assets folder?

    - by Peter SHINe ???
    I guess many people already read this article: Using your own SQLite database in Android applications: http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/comment-page-2/#comment-12368 However it's keep bringing IOException at while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } I’am trying to use a large DB file. It’s as big as 8MB I built it using sqlite3 in Mac OS X, inserted UTF-8 encoded strings (for I am using Korean), added android_meta table with ko_KR as locale, as instructed above. However, When I debug, it keeps showing IOException at length=myInput.read(buffer) I suspect it’s caused by trying to read a big file. If not, I have no clue why. I tested the same code using much smaller text file, and it worked fine. Can anyone help me out on this? I’ve searched many places, but no place gave me the clear answer, or good solution. Good meaning efficient or easy. I will try use BufferedInput(Output)Stream, but if the simpler one cannot work, I don’t think this will work either. Can anyone explain the fundamental limits in file input/output in Android, and the right way around it, possibly? I will really appreciate anyone’s considerate answer. Thank you. WITH MORE DETAIL: private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = myContext.getAssets().open(DB_NAME); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); }

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  • How do I use foreach with QDomNodeList in Qt?

    - by Venemo
    Hi Everyone, I'm new to Qt and I'm learning something new every day. Currently, I'm developing a small application for my Nokia N900 in my free time. Everything is fine, I am able to compile and run Maemo applications on the device. I've just learned about the foreach keyword in Qt. (I know it is not in C++, so I didn't think about it until I accidentally stumbled upon a Qt doc that mentioned it.) So, I decided to change my quite annoying and unreadable loops to foreach, but I failed with this: QDomNodeList list = doc.lastChild().childNodes().at(1).firstChild().childNodes(); for (int x = 0; x < list.count(); x++) { QDomElement node = list.at(x).toElement(); // Do something with node } This is how I tried: foreach (QDomElement node, doc.lastChild().childNodes().at(1).firstChild().childNodes()) { // Do something with node } For some reason the above code doesn't even compile. I get cryptic error messages from the compiler. Could someone please explain to me how to get it right? If the foreach loop doesn't support QDomNodeList, is there a way of handling XML files that do support foreach?

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  • Why aren't google api clients built on top of Apache's Abdera project ?

    - by lisak
    Hey, Could anybody please explain that to me? As far as I can see, the developers of java's google api client library are reinventing the wheel. It's like writing a new JDK for a Java project. I'm aware of the fact that google data protocol is a little specific re atom publishing, but if one needs to use some of the fancy extensions and features that Apache Abdera project offers for this protocol, it is better not to use google api client library and implement the client from scratch with Abdera... And I'm sure that in a lot of cases its features such as Abdera's JCR adapter would become very handy for google docs, google translator toolkit and others. Now it's great that there is a google api client library to be used for google docs, but what am I going to do with the documents? I believe that in more than a half cases there is also a repository or database on the other side. And in that case, abdera is needed, not the simple google api clients that are only marshalling/unmarshalling the feeds... In fact, there is something to persist in all of the google APIs. It would make sense, if google decided to invest the effort into Abdera enhancement... This doesn't... Also for the question to be more specific: How are you developing google api clients, that need entry persistence (JCR for instance) ? What would be the best way to integrate a google api client library with Apache Abdera ?

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  • Programming test for ASP.NET C# developer job - Opinions please!

    - by Indy
    Hi all, We are hiring a .NET C# developer and I have developed a technical test for the candidates to complete. They have an hour and it has two parts, some knowledge based questions covering asp.net, C# and SQL and a small practical test. I'd appreciate feedback on the test, is it sufficient to test the programmers ability? What would you change if anything? Part One. What the are events fired as part of the ASP.NET Page lifecycle. What interesting things can you do at each? How does ViewState work and why is it either useful or bad? What is a common way to create web services in ASP.NET 2.0? What is the GAC? What is boxing? What is a delegate? The C# keyword .int. maps to which .NET type? Explain the difference between a Stored Procedure and a Trigger? What is an OUTER Join? What is @@IDENTITY? Part Two: You are provided with the Northwind Database and the attached DB relationship diagram. Please create a page which provides users with the following functionality. You don’t need to be too concerned with the presentation detail of the page. Select a customer from a list, and see all the orders placed by that customer. For the same customer, find all their orders which are Beverages and the quantity is more than 5. I was aware of setting the right balance of difficulty on this as there is an hour's test. I was able to complete the practical test in under 30 mins using SQLDatasource and the query designer in visual studio and the test questions, I am looking to see how they approach it logically and whether they use the tools available. Many thanks!

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  • How can I catch an invalid fgetpos call as a C++ exception on Windows?

    - by Brent Arias
    In Visual C++ 2008, I want to "catch" an exception generated as shown here: try { int foo = 20; ::fgetpos(0, (fpos_t*)&foo); } //... Here are adjustments I've made to attempt a successful catch: SEH is activated (/eha) I've added a catch(...) I've added a _set_se_translator vector. I've added/adjusted to SEH syntax: __try / __except(EXCEPTION_EXECUTE_HANDLER) In short, I've tried "everything in the book" and I still can't catch the exception. If I replace the call to ::fgetpos with int hey = foo / 0 then suddenly all of the above techniques work as expected. So the exception I'm dealing with from ::fgetpos is somehow "extra special." Can someone explain why this ::fgetpos error seems uncatchable, and how to work around it? update When executed in the VS IDE, the output window doesn't name an exception. All it says is this: Microsoft Visual Studio C Runtime Library has detected a fatal error in MyProgram.exe. Not very helpful. When I run the console app from the command line, I get a crash dialogue. The "problem details" section of the dialogue includes this information: Problem Event Name: BEX Exception Offset:0002fd30 Exception Code: c0000417 Exception Data: 00000000 Additional Information 1:69ad Additional Information 2:69addfb19767b2221c8e3e7a5cd2f4ae Additional Information 3:b1ff Additional Information 4:b1ffca30cadddc78c19f19b6d150997f

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  • Combining data sets without losing observations in SAS

    - by John
    Hye guys, I know, another post another problem :D :(. I took a screenshot to easily explain my problem. http://i39.tinypic.com/rhms0h.jpg As you can see I want to merge two tables (again), the Base & Analyst table. What I want to achieve is displayed in the right bottom corner table. I’m calculating the number of total analysts and female analysts for each month in the analyst table. In the base table I have different observations for one company (here company Alcoa with ticker AA). When I use the following command: data want; merge base analyst; by month ; run; I get the right up corner problem. My observations in the main table are being narrowed down to only 4 observations (for each different year one observation, 2001, 2002, 2005, 2006). What I want is that the observations are not reduced but that for every year the same data is being placed as shown in the right bottom corner. What am I missing in my merge command? In both tables I have month as a time count variable ( the observations in my base table are monthly) on which I need to merge. For clarity I added 2 screenshots of my real databases in SAS. The base table: http://i42.tinypic.com/dr5jky.jpg The analyst table: http://i40.tinypic.com/eqpmqq.jpg Here is what my merged table looks like: http://i43.tinypic.com/116i62s.jpg You can clearly see that the merged table only has four observations left for AA (one for each unique year) instead of the original 8. Anyone an idea to solve this?

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  • AJAX Partial Rendering issues for the default page in IIS 7 when using custom http module

    - by WiseGuyEh
    The problem When I try to make a AJAX partial update request (using the UpdatePanel control) from the default page of an IIS7 web site, it fails- instead of returning the html to be updated, it returns the entire page, which then causes the MS AJAX Javascript to throw a parsing shit-fit. The suspected cause I have narrowed the cause down to two issues- making an AJAX request to the default page when I have a certain custom http module registered. A partial rendering request to http://localhost will fail, but a partial rendering request to http://localhost/default.aspx will work fine. Also, If i remove the following line in my custom HttpModule: _application.PreRequestHandlerExecute += OnPreRequestHandlerExecute; The AJAX partial render will work correctly. Wierd huh? Another wierd thing... If I look at trace.axd, I can see that when a partial rendering request fails, two POST requests are logged for the one partial rendering request- one where the default.aspx page executes successfully (trace information such as page_load is logged) but no content is produced and a second that doesn't seem to actually execute (no trace information is logged) but produces content (HTTP_CONTENT_LENGTH is greater than 0). Please help! If anyone with a good knowledge of HTTP modules or the MS AJAX Http module could explain why this is occuring I would be very grateful. As it is, the obvious work arround is to just redirect to default.aspx if the request url is "/" but I would really like to understand why this is occurring.

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  • What should a developer know before building a public web site?

    - by Joel Coehoorn
    What things should a programmer implementing the technical details of a web site address before making the site public? If Jeff Atwood can forget about HttpOnly cookies, sitemaps, and cross-site request forgeries all in the same site, what important thing could I be forgetting as well? I'm thinking about this from a web developer's perspective, such that someone else is creating the actual design and content for the site. So while usability and content may be more important than the platform, you the programmer have little say in that. What you do need to worry about is that your implementation of the platform is stable, performs well, is secure, and meets any other business goals (like not cost too much, take too long to build, and rank as well with Google as the content supports). Think of this from the perspective of a developer who's done some work for intranet-type applications in a fairly trusted environment, and is about to have his first shot and putting out a potentially popular site for the entire big bad world wide web. Also: I'm looking for something more specific than just a vague "web standards" response. I mean, HTML, JavaScript, and CSS over HTTP are pretty much a given, especially when I've already specified that you're a professional web developer. So going beyond that, Which standards? In what circumstances, and why? Provide a link to the standard's specification. This question is community wiki, so please feel free to edit that answer to add links to good articles that will help explain or teach each particular point.

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  • Trigger doesn't work

    - by Pasha
    Hello everyone, I have an user control, It is editable text block. The content of the control is: <DataTemplate x:Key="DisplayModeTemplate"> <TextBlock Text="{Binding ElementName=mainControl, Path=FormattedText}" Margin="5,3,5,3" /> </DataTemplate> <Style TargetType="{x:Type Controls:EditableTextBlock}"> <Setter Property="ContentTemplate" Value="{StaticResource EditModeTemplate}"/> <Style.Triggers> <Trigger Property="IsInEditMode" Value="True"> <Setter Property="ContentTemplate" Value="{StaticResource EditModeTemplate}" /> </Trigger> <Trigger Property="IsInEditMode" Value="False"> <Setter Property="ContentTemplate" Value="{StaticResource DisplayModeTemplate}" /> </Trigger> </Style.Triggers> </Style> </UserControl.Resources> Also i have another window with tree view: When treeView1_KeyDown fires I set IsInEditMode to true, but it seems that trigger doesn't work, because content template don't change. Anyone, please explain me why?

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  • php calculate float HELP!!

    - by apis17
    help!! i have weird math calculation here. hope someone will explain. $a = 1.85/100; $b = 1.5/100; $c = 1.1/100; $d = 0.4/100; $e = 0.4/100; $f = 0.4/100; $g = 0.4/100; $h = $a + $b + $c + $d + $e + $f + $g; echo $h*100 ."<br>"; $i = $h-$a; $i = $i-$b; $i = $i-$c; $i = $i-$d; $i = $i-$e; $i = $i-$f; $i = $i-$g; echo $i; last $i value should be 0 but it returns 6.93889390391E-18

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  • Algorithm to see if keywords exist inside a string

    - by rksprst
    Let's say I have a set of keywords in an array {"olympics", "sports tennis best", "tennis", "tennis rules"} I then have a large list (up to 50 at a time) of strings (or actually tweets), so they are a max of 140 characters. I want to look at each string and see what keywords are present there. In the case where a keyword is composed of multiple words like "sports tennis best", the words don't have to be together in the string, but all of them have to show up. I've having trouble figuring out an algorithm that does this efficiently. Do you guys have suggestions on a way to do this? Thanks! Edit: To explain a bit better each keyword has an id associated with it, so {1:"olympics", 2:"sports tennis best", 3:"tennis", 4:"tennis rules"} I want to go through the list of strings/tweets and see which group of keywords match. The output should be, this tweet belongs with keyword #4. (multiple matches may be made, so anything that matches keyword 2, would also match 3 -since they both contain tennis). When there are multiple words in the keyword, e.g. "sports tennis best" they don't have to appear together but have to all appear. e.g. this will correctly match: "i just played tennis, i love sports, its the best"... since this string contains "sports tennis best" it will match and be associated with the keywordID (which is 2 for this example).

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  • Is there an event that raises after a View/PartialView executes in ASP.NET MVC 2 RC2?

    - by sabanito
    I have the following problem: We have an ASP.NET MVC 2 RC 2 application that programmatically impersonates an AD Account that the user specifies at logon. This account is used to access the DB. At first we had the impersonating code in the begin_request and we were undoing the impersonation at the end_request, but when we tried to use IIS 7.5 in integrated mode, we learned that it's not possible to impersonate in the Global.asax so we tried different things. We have succesfully moved our code from the BeginRequest to the ActionExecuting event and the EndRequest to the ResultExecuted, and now, about 80% of our code works. We've just discovered that since we're passing the Entity Framework objects as models for our views, there's this remaining 20% that won't work because some Navigation Properties are not loaded when the view begins it's execution, so we're getting connection exceptions from Sql Server. Is there any event or method that executes AFTER the view, so we can undo the impersonation in it? We thought ResultExecuted will do just that, but it doesn't. We've been told that passing the plain Entities into the view as models is not a good idea, but we have A LOT of views that may have this problem and there's not automated way to know it. If some of you could explain why it's not a good idea, maybe we can convince the team to fix it!

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  • Some help required while working on Java and Cygwin together

    - by Hippo
    Hello .. I am new to java and also cygwin . I do not have in detailed knowledge of both . I need some help.. I simple steps i will try to explain my problem. 1) I am working on tinyOS . its open source OS , used for wireless sensor networks. It provides java libraries to work on communication (PC to sensor) 2) I am working on windows xp environment through cigwin. 3) I am developing an application . THis application requires one java interface called "Serial Forwarder" , which is readily available in libraries provided. Previously i used to start this interface manually (by entering command *"java net.tinyos.sf.SerialForwarder ")*and then my application which uses this interface. But now i want to make my application independent . User need know about this background cygwin commands . 4) So in my java application i used "Runtime.getRuntime().exec( "java net.tinyos.sf.SerialForwarder)" . 5) This i neither giving any error nor starting the interface. Am I going on right way ? When i am using runtime execute command , how can i make sure that this command is called through cigwin interface ? Also .. if i want to write .bat file .. i which i can give commands which will be executed .. how can i make sure that those commands are given through cigwin .. and not through cmd.exe .. Please help . me .

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  • JQuery Deferred - Adding to the Deferred contract

    - by MgSam
    I'm trying to add another asynchronous call to the contract of an existing Deferred before its state is set to success. Rather than try and explain this in English, see the following pseudo-code: $.when( $.ajax({ url: someUrl, data: data, async: true, success: function (data, textStatus, jqXhr) { console.log('Call 1 done.') jqXhr.pipe( $.ajax({ url: someUrl, data: data, async: true, success: function (data, textStatus, jqXhr) { console.log('Call 2 done.'); }, }) ); }, }), $.ajax({ url: someUrl, data: data, async: true, success: function (data, textStatus, jqXhr) { console.log('Call 3 done.'); }, }) ).then(function(){ console.log('All done!'); }); Basically, Call 2 is dependent on the results of Call 1. I want Call 1 and Call 3 to be executed in parallel. Once all 3 calls are complete, I want the All Done code to execute. My understanding is that Deferred.pipe() is supposed to chain another asynchronous call to the given deferred, but in practice, I always get Call 2 completing after All Done. Does anyone know how to get jQuery's Deferred to do what I want? Hopefully the solution doesn't involve ripping the code apart into chunks any further. Thanks for any help.

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  • Binding event handlers to specific elements, using bubbling (JavaScript/jQuery)

    - by Bungle
    I'm working on a project that approximates the functionality of Firebug's inspector tool. That is, when mousing over elements on the page, I'd like to highlight them (by changing their background color), and when they're clicked, I'd like to execute a function that builds a CSS selector that can be used to identify them. However, I've been running into problems related to event bubbling, and have thoroughly confused myself. Rather than walk you down that path, it might make sense just to explain what I'm trying to do and ask for some help getting started. Here are some specs: I'm only interested in elements that contain a text node (or any descendant elements with text nodes). When the mouse enters such an element, change its background color. When the mouse leaves that element, change its background color back to what it was originally. When an element is clicked, execute a function that builds a CSS selector for that element. I don't want a mouseover on an element's margin area to count as a mouseover for that element, but for the element beneath (I think that's default browser behavior anyway?). I can handle the code that highlights/unhighlights, and builds the CSS selector. What I'm primarily having trouble with is efficiently binding event handlers to the elements that I want to be highlightable/clickable, and avoiding/stopping bubbling so that mousing over a (<p>) element doesn't also execute the handler function on the <body>, for example. I think the right way to do this is to bind event handlers to the document element, then somehow use bubbling to only execute the bound function on the topmost element, but I don't have any idea what that code looks like, and that's really where I could use help. I'm using jQuery, and would like to rely on that as much as possible. Thanks in advance for any guidance!

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  • JSF - managed bean in variable?

    - by Yurish
    Hi! Weird question, but i need to find an answer. Is there any way, in which i can manage managed beans in JSP? I`ll try to explain, what i want to do: Imagine, i have JSP page, which, for example, is called document.save.jsp. I have some various documents with different types. Each of them have their own bean. For example: BillDocument.java, OrderDocument.java and ReportDocument.java. BillDocument.java in my jsp is #{billdoc}. OrderDocument.java - #{orddoc}. ReportDocument.java - #{repdoc}. Each of them have method save(). In my JSP i want to call this method, but i need to know, which document it is. In my mind this structure is something like: <% String currentBean = ""; if(document == BillDocument){ currentBean = #{billdoc}; } if(document == OrderDocument){ currentBean = #{orddoc}; } if(document = ReportDocument){ currentBean = #{repdoc}; } %> Then, my Button with save method on it, may be smth like: <h:commandButton action="currentbean.save"/> Is there any way, in which i can store data about bean, which will be used in this button? Thank`s for your replies!

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  • java class creation dynamically and make it accessible across the network different jvms i.e. serial

    - by inj.rav
    Hi. I have a requirement of creating java classes dynamically and make it accessible different jvms across the network. I tried to use reflection and javassist tool,but nothing worked. Let me explain the scenario we are using Coherence distributed cache. It has a power of doing aggregation/filtering in parallel across the cluster. For example if a class has [dynamic class] has amount variable and getAmount/setAmount methods. Then if we execute COHERENCE queries, it will start process in parallel across the cluster. I tried to create classes at run time by using javassist and reflection. I am able to access it from single JVM, but when I tried to access the same class from other jvm [through coherence cluster]. I am getting exception of class not found [as remote jvm is not having idea of this class].I can over come this by creating same class dynamically on remote jvm also and access the methods. But coherence in built methods/functions are not able to find the class. could some one help me on this matter

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  • Database sharing/versioning

    - by DarkJaff
    Hi everyone, I have a question but I'm not sure of the word to use. My problem: I have an application using a database to stock information. The database can ben in access (local) or in a server (SQL Server or Oracle). We support these 3 kind of database. We want to give the possibility to the user to do what I think we can call versioning. Let me explain : We have a database 1. This is the master. We want to be able to create a database 2 that will be the same thing as database 1 but we can give it to someone else. They each work on each other side, adding, modifying and deleting records on this very complex database. After that, we want the database 1 to include the change from database 2, but with the possibility to dismiss some of the change. For you information, ou application is already multiuser so why don't we just use this multi-user and forget about this versionning? It's because sometimes, we need to give a copy of the database to another company on another site and they can't connect on our server. They work on their side and then, we want to merge. Is there anyone here with experience with this type of requirement? We have a lot of ideas but most of them require a LOT of work, massive modification to the database or to the existing queries. This is a 2 millions and growing C++ app, so rewriting it is not possible! Thanks for any ideas that you may give us! J-F

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  • Mysterious extra hashtable entry

    - by Harm De Weirdt
    Good evening everyone, I'm back :) Let me explain my problem. I have a hashtable in wich I store the products a costumors buys (%orders). It uses the productcode as key and has a reference to an array with the other info as value. At the end of the program, I have to rewrite the inventory to the updated version (i.e. subtract the quantity of the bought items) This is how I do this: sub rewriteInventory{ open(FILE,'>inv.txt'); foreach $key(%inventory){ print FILE "$key\|$inventory{$key}[0]\|$inventory{$key}[1]\|$inventory{$key}[2]\n" } close(FILE); } where $inventory{$key}[x] is 0 - Title, 1 - price, 2 - quantity. The problem here is that when I look at inv.txt afterwards, I see things like this: CD-911|Lady Gaga - The Fame|15.99|21 ARRAY(0x145030c)||| BOOK-1453|The Da Vinci Code - Dan Brown|14.75|12 ARRAY(0x145bee4)||| Where do these "ARRAY(0x145030c)|||" entries come from? Or more important, how do I get rid of them? This is the last part of this school task, I had so much problems programming all this and this stupid little thing comes up now and I'm really fed up with this whole Perl thing. (this aside :p) I hope someone can help me :) Fuji

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  • Returning recursive ternary freaks out

    - by David Titarenco
    Hi, assume this following function: int binaryTree::findHeight(node *n) { if (n == NULL) { return 0; } else { return 1 + max(findHeight(n->left), findHeight(n->right)); } } Pretty standard recursive treeHeight function for a given binary search tree binaryTree. Now, I was helping a friend (he's taking an algorithms course), and I ran into some weird issue with this function that I couldn't 100% explain to him. With max being defined as max(a,b) ((a)>(b)?(a):(b)) (which happens to be the max definition in windef.h), the recursive function freaks out (it runs something like n^n times where n is the tree height). This obviously makes checking the height of a tree with 3000 elements take very, very long. However, if max is defined via templating, like std does it, everything is okay. So using std::max fixed his problem. I just want to know why. Also, why does the countLeaves function work fine, using the same programmatic recursion? int binaryTree::countLeaves(node *n) { if (n == NULL) { return 0; } else if (n->left == NULL && n->right == NULL) { return 1; } else { return countLeaves(n->left) + countLeaves(n->right); } } Is it because in returning the ternary function, the values a => countLeaves(n->left) and b => countLeaves(n->right) were recursively double called simply because they were the resultants? Thank you!

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  • database schema eligible for delta synchronization

    - by WilliamLou
    it's a question for discussion only. Right now, I need to re-design a mysql database table. Basically, this table contains all the contract records I synchronized from another database. The contract record can be modified, deleted or users can add new contract records via GUI interface. At this stage, the table structure is exactly the same as the Contract info (column: serial number, expiry date etc.). In that case, I can only synchronize the whole table (delete all old records, replace with new ones). If I want to delta(only synchronize with modified, new, deleted records) synchronize the table, how should I change the database schema? here is the method I come up with, but I need your suggestions because I think it's a common scenario in database applications. 1)introduce a sequence number concept/column: for each sequence, mark the new added records, modified records, deleted records with this sequence number. By recording the last synchronized sequence number, only pass those records with higher sequence number; 2) because deleted contracts can be added back, and the original table has primary key constraints, should I create another table for those deleted records? or add a flag column to indicate if this contract has been deleted? I hope I explain my question clearly. Anyway, if you know any articles or your own suggestions about this, please let me know. Thanks!

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  • Python: query a class's parent-class after multiple derivations ("super()" does not work)

    - by henry
    Hi, I have built a class-system that uses multiple derivations of a baseclass (object-class1-class2-class3): class class1(object): def __init__(self): print "class1.__init__()" object.__init__(self) class class2(class1): def __init__(self): print "class2.__init__()" class1.__init__(self) class class3(class2): def __init__(self): print "class3.__init__()" class2.__init__(self) x = class3() It works as expected and prints: class3.__init__() class2.__init__() class1.__init__() Now I would like to replace the 3 lines object.__init__(self) ... class1.__init__(self) ... class2.__init__(self) with something like this: currentParentClass().__init__() ... currentParentClass().__init__() ... currentParentClass().__init__() So basically, i want to create a class-system where i don't have to type "classXYZ.doSomething()". As mentioned above, I want to get the "current class's parent-class". Replacing the three lines with: super(type(self), self).__init__() does NOT work (it always returns the parent-class of the current instance - class2) and will result in an endless loop printing: class3.__init__() class2.__init__() class2.__init__() class2.__init__() class2.__init__() ... So is there a function that can give me the current class's parent-class? Thank you for your help! Henry -------------------- Edit: @Lennart ok maybe i got you wrong but at the moment i think i didn't describe the problem clearly enough.So this example might explain it better: lets create another child-class class class4(class3): pass now what happens if we derive an instance from class4? y = class4() i think it clearly executes: super(class3, self).__init__() which we can translate to this: class2.__init__(y) this is definitly not the goal(that would be class3.__init__(y)) Now making lots of parent-class-function-calls - i do not want to re-implement all of my functions with different base-class-names in my super()-calls.

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  • WINE error when running windows application

    - by Colen
    Hello, A user reports that one of our applications doesn't work under WINE. It runs until he proceeds past a certain form, and then freezes. WINE gives the following output: ~/.wine/drive_c/HeroLab$ wine HeroLab.exe fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:HTTPREQ_QueryOption Semi-STUB INTERNET_OPTION_SECURITY_FLAGS: 0 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_SECURITY_FLAGS; STUB fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:wininet:InternetSetOptionW INTERNET_OPTION_SEND/RECEIVE_TIMEOUT 30000 fixme:wininet:InternetSetOptionW Option INTERNET_OPTION_CONNECT_TIMEOUT (30000): STUB fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:bitmap:CreateBitmapIndirect planes = 0 Can anyone explain these messages to me? I assume they are messages from WINE reporting that we are calling functions in ways that WINE doesn't support, but our code doesn't call CreateBitmapIndirect at all. How can we locate the source of this problem, and fix our app so it runs under WINE? Thanks.

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  • Design Decision - Scaling out web based application's architecture

    - by Vadi
    This question is about design decision. I am currently working on a web project that will have 40K users to start with and in couple of month expected to grow 50M users (not concurrent users though). I would like to have a architecture that can be scaled out easily without much effort. In order to explain, I would like to use a trivial scenario. Lets say, User entities and services such as CreateUser, AuthenticateUser etc., are a simple method calls for the Page Controllers. But once the traffic increases, for example, authenticating user (or such services related to user entities) has to be moved out to a different internal server to spread the load. But at the same time using RPC calls over the network when the user count is 40K would become overkill. My proposal was to use IPC initially and when we need to scale out we can interally switch to TCP based RPC calls so that it can easily scale out. For example, I am referring to System.IO.Pipes.NamedPipeStreamServer to start with and move on to a TcpListener later on. If we have proper design that can encapsulate above said approach, it would easy for us to scale out services into multiple network servers but at the same time avoid network calls when the user count is small. Is this is a best approach? Any suggestions would be great .. Note: The database scaling is definetly the second phase optimization so we have already made architectural design in place to easily partition data when traffic increases. The primary bottleneck would be application servers over the time period.

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