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  • TCP: Address already in use exception - possible causes for client port? NO PORT EXHAUSTION

    - by TomTom
    Hello, stupid problem. I get those from a client connecting to a server. Sadly, the setup is complicated making debugging complex - and we run out of options. The environment: *Client/Server system, both running on the same machine. The client is actually a service doing some database manipulation at specific times. * The cnonection comes from C# going through OleDb to an EasySoft JDBC driver to a custom written JDBC server that then hosts logic in C++. Yeah, compelx - but the third party supplier decided to expose the extension mechanisms for their server through a JDBC interface. Not a lot can be done here ;) The Symptom: At (ir)regular intervals we get a "Address already in use: connect" told from the JDBC driver. They seem to come from one particular service we run. Now, I did read all the stuff about port exhaustion. This is why we have a little tool running now that counts ports and their states every minute. Last time this happened, we had an astonishing 370 ports in use, with the count rising to about 900 AFTER the error. We aleady patched the registry (it is a windows machine) to allow more than the 5000 client ports standard, but even then, we are far far from that limit to start with. Which is why I am asking here. Ayneone an ide what ELSE could cause this? It is a Windows 2003 Server machine, 64 bit. The only other thing I can see that may cause it (but this functionality is supposedly disabled) is Symantec Endpoint Protection that is installed on the server - and being capable of actinc as a firewall, it could possibly intercept network traffic. I dont want to open a can of worms by pointing to Symantec prematurely (if pointing to Symantec can ever be seen as such). So, anyone an idea what else may be the cause? Thanks

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  • Rails: constraint violation on create but not on update

    - by justinbach
    Note: This is a "railsier" (and more succinct) version of this question, which was getting a little long. I'm getting Rails behavior on a production server that I can't replicate on the development server. The codebases are identical save for credentials and caching settings, and both are powered by Oracle 10g databases with identical schema (but different data). My Rails application contains a user model, which has_one registration; registration in turn has_and_belongs_to_many company_ownerships through a registration_ownerships table. Upon registering, users fill out data pertinent to all three models, including a series of checkboxes indicating what registration_ownerships might apply to their account. On the dev server, the registration process is seamless, no matter what data is entered. On production, however, if users check off any of the company ownership fields before submitting their registration, Oracle complains about a constraint violation on the primary key of the company_ownerships table (which is a two-field key based on company_ownership_id and registration_id) and users get the standard Rails 500 error screen. In every case, I've verified that no conflicting record on these two fields exists in the production database, so I don't know why the constraint is getting violated. To further confuse things, if a user registers without listing any ownerships and later goes back and modifies their account to reflect ownership data (which is done through the same interface), the application happily complies with their request and Oracle is well-behaved (this is both on production and dev). I've spent the past couple days trying to figure out what might be causing this problem and am reaching the end of my wits. Any advice would be greatly appreciated!

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  • 4.0/WCF: Best approach for bi-idirectional message bus?

    - by TomTom
    Just a technology update, now that .NET 4.0 is out. I write an application that communicates to the server through what is basically a message bus (instead of method calls). This is based on the internal architecture of the application (which is multi threaded, passing the messages around). There are a limited number of messages to go from the client to the server, quite a lot more from the server to the client. Most of those can be handled via a separate specialized mechanism, but at the end we talk of possibly 10-100 small messages per second going from the server to the client. The client is supposed to operate under "internet conditions". THis means possibly home end users behind standard NAT devices (i.e. typical DSL routers) - a firewalled secure and thus "open" network can not be assumed. I want to have as little latency and as little overhad for the communication as possible. What is the technologally best way to handle the message bus callback? I Have no problem regularly calling to the server for message delivery if something needs to be sent... ...but what are my options to handle the messagtes from the server to the client? WsDualHttp does work how? Especially under a NAT scenario? Just as a note: polling is most likely out - the main problem here is that I would have a significant overhead OR a significant delay, both aren ot really wanted. Technically I would love some sort of streaming appraoch, where the server can write messags to a stream while he generates them and they get sent to the client as they come. Not esure this is doable with WCF, though (if not, I may acutally decide to handle the whole message part outside of WCF and just do control / login / setup / destruction via WCF).

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  • What are some programming techniques for converting SD images to HD images

    - by Dr Dork
    I'm taking programming class and instructor loves to work with images so most of our assignments involve manipulating raw RGB image data. One of our assignments is to implement a standard image converter that converts SD images to HD images and vice versa. I always take advantage of these types of assignments to go a little beyond what we were asked to do, so I added a basic anti-aliasing process that uses the average pixel color of the 3x3 surrounding pixels to improve the converted image. While it helps a bit, the resulting image still doesn't look good, which is ok because it's not expected to for the assignment. I've learned that converting an SD to HD images has shown to be much harder than down sampling to SD from HD just because SD to HD effectively involves increasing resolution when it is not there. Obviously, it is hard to create pixels from nothing, but I'd like enhance my anti-aliasing to something that provides better results when upscaling an image. Most of the techniques I find and read on the internet are far beyond my level of image processing and programming. Can anybody suggest any better methods or processes to create good HD content from SD content that may be within my programming skill level? I know that's a difficult thing to gauge since you don't know me, but perhaps knowing that I can write c++ code to read in raw RGB data and upscale/downscale it with simple average-anti-aliasing will give you an idea. Thanks in advance for all your help!

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  • What is the name of this geometrical function?

    - by Spike
    In a two dimentional integer space, you have two points, A and B. This function returns an enumeration of the points in the quadrilateral subset bounded by A and B. A = {1,1} B = {2,3} Fn(A,B) = {{1,1},{1,2},{1,3},{2,1},{2,2},{2,3}} I can implement it in a few lines of LINQ. private void UnknownFunction(Point to, Point from, List<Point> list) { var vectorX = Enumerable.Range(Math.Min(to.X, from.X), Math.Abs(to.X - from.Y) + 1); var vectorY = Enumerable.Range(Math.Min(to.Y, from.Y), Math.Abs(to.Y - from.Y) + 1); foreach (var x in vectorX) foreach (var y in vectorY) list.Add(new Point(x, y)); } I'm fairly sure that this is a standard mathematical operation, but I can't think what it is. Feel free to tell me that it's one line of code in your language of choice. Or to give me a cunning implementation with lambdas or some such. But mostly I just want to know what it's called. It's driving me nuts. It feels a little like a convolution, but it's been too long since I was at school for me to be sure.

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  • SubViewTwoController undeclared (first use in this function) (obj-c)

    - by benny
    Ahoy hoy everyone :) Here is a list of links. You will need it when reading the post. I am a newbie to Objective-C and try to learn it for iPhone-App-Development. I used the tutorial linked in the link list to create a standard app with a simple basic Navigation. This app contains a "RootView" that is displayed at startup. The startup screen itself contains three elements wich all link to SubViewOne. I have got it to work this far. So what i want to change is to make the second element link to SubViewTwo. When i "Build and Go" it, i get the following errors: RootViewController.m: SubViewTwoController *subViewTwoController = [[SubViewTwoController alloc] init]; // SubViewTwoController undeclared (first use in this function) and in SubViewTwoController.m [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview no superclass declared in @interface for ´SubViewTwoController´ and the same thing after - (void)dealloc { [super dealloc]; I think you will also need the header files, so here they are! RootViewController.h #import <UIKit/UIKit.h> @interface RootViewController : UITableViewController { IBOutlet NSMutableArray *views; } @property (nonatomic, retain) IBOutlet NSMutableArray *views; @end SubViewOneController.h #import <UIKit/UIKit.h> @interface SubViewOneController : UIViewController { IBOutlet UILabel *label; IBOutlet UIButton *button; } @property (retain,nonatomic) IBOutlet UILabel *label; @property (retain,nonatomic) IBOutlet UIButton *button; - (IBAction) OnButtonClick:(id) sender; @end and SubViewTwoController.h #import <UIKit/UIKit.h> @interface SubViewTwo : UIViewController { IBOutlet NSMutableArray *views; } @end I would be really great if you would leave your ideas with a short explanation. Thanks a lot in advance! benny

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  • How can I factor out repeated expressions in an SQL Query? Column aliases don't seem to be the ticke

    - by Weston C
    So, I've got a query that looks something like this: SELECT id, DATE_FORMAT(CONVERT_TZ(callTime,'+0:00','-7:00'),'%b %d %Y') as callDate, DATE_FORMAT(CONVERT_TZ(callTime,'+0:00','-7:00'),'%H:%i') as callTimeOfDay, SEC_TO_TIME(callLength) as callLength FROM cs_calldata WHERE customerCode='999999-abc-blahblahblah' AND CONVERT_TZ(callTime,'+0:00','-7:00') >= '2010-04-25' AND CONVERT_TZ(callTime,'+0:00','-7:00') <= '2010-05-25' If you're like me, you probably start thinking that maybe it would improve readability and possibly the performance of this query if I wasn't asking it to compute CONVERT_TZ(callTime,'+0:00','-7:00') four separate times. So I try to create a column alias for that expression and replace further occurances with that alias: SELECT id, CONVERT_TZ(callTime,'+0:00','-7:00') as callTimeZoned, DATE_FORMAT(callTimeZoned,'%b %d %Y') as callDate, DATE_FORMAT(callTimeZoned,'%H:%i') as callTimeOfDay, SEC_TO_TIME(callLength) as callLength FROM cs_calldata WHERE customerCode='5999999-abc-blahblahblah' AND callTimeZoned >= '2010-04-25' AND callTimeZoned <= '2010-05-25' This is when I learned, to quote the MySQL manual: Standard SQL disallows references to column aliases in a WHERE clause. This restriction is imposed because when the WHERE clause is evaluated, the column value may not yet have been determined. So, that approach would seem to be dead in the water. How is someone writing queries with recurring expressions like this supposed to deal with it?

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  • Linking AS code to symbols defined in an external SWC?

    - by Ender
    (apologies ahead of time, I only really know Flash; my Flex experience is basically nil. There may be a very standard and obvious workflow solution that Flex people know about) I have a number of UI elements that are graphically quite complex (they're not components, they're just Sprites). Since it takes a long time to compile them, I've been trying to move them into an external .swc. However, I want to associate some code with these classes, but I don't want to have to recompile the graphical assets every time I make a code change. At the moment I have it set up like this: UI elements are created in a separate FLA and exported to a SWC. In my primary FLA, I have actionscript classes that extend each of the graphical assets in the SWC. For example: external.swc: (some symbol defined in the Library and exported for actionscript in frame 1) class: com.foo.WidgetGraphic base: flash.display.Sprite main.fla: Widget.as: package com.foo { public class Widget extends WidgetGraphic { ... } } This works, but is time-consuming and prone to error. I'd rather be able to avoid having to inherit from each graphical asset, and just define them directly. Is there a better way to do what I'm trying to accomplish? Note: the main concern here is compile time. I don't have any movies or audio or fonts, just a lot of vector art assets that appear to be slowing down my compilation time significantly. When I'm debugging I'm only making code changes, and would rather not have to keep recompiling the art...

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  • Base class deleted before subclass during python __del__ processing

    - by Oddthinking
    Context I am aware that if I ask a question about Python destructors, the standard argument will be to use contexts instead. Let me start by explaining why I am not doing that. I am writing a subclass to logging.Handler. When an instance is closed, it posts a sentinel value to a Queue.Queue. If it doesn't, a second thread will be left running forever, waiting for Queue.Queue.get() to complete. I am writing this with other developers in mind, so I don't want a failure to call close() on a handler object to cause the program to hang. Therefore, I am adding a check in __del__() to ensure the object was closed properly. I understand circular references may cause it to fail in some circumstances. There's not a lot I can do about that. Problem Here is some simple example code: explicit_delete = True class Base: def __del__(self): print "Base class cleaning up." class Sub(Base): def __del__(self): print "Sub-class cleaning up." Base.__del__(self) x = Sub() if explicit_delete: del x print "End of thread" When I run this I get, as expected: Sub-class cleaning up. Base class cleaning up. End of thread If I set explicit_delete to False in the first line, I get: End of thread Sub-class cleaning up. Exception AttributeError: "'NoneType' object has no attribute '__del__'" in <bound method Sub.__del__ of <__main__.Sub instance at 0x00F0B698>> ignored It seems the definition of Base is removed before the x._del_() is called. The Python Documentation on _del_() warns that the subclass needs to call the base-class to get a clean deletion, but here that appears to be impossible. Can you see where I made a bad step?

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  • What issues to consider when rolling your own data-backend for Silverlight / AJAX on non-ASP.NET ser

    - by Edward Tanguay
    I have read-only Silverlight and AJAX apps which read static text and XML files from a PHP/Apache server, which works very nicely with features such as asynchronous loading, lazy-loading only what I need for each page, loading in the background, developed a little query language to get a PHP script to create custom XML files etc. it's pragmatic read-only REST, and all works fast and fine for read-only sites. Now I want to also add the ability to write data from these apps to a database on the same PHP/Apache server. For those of you who have built similar data-access layers, what do I need to consider while building this, especially regarding security so that not just any client can write and alter my database, e.g.: check HTTP_USER_AGENT for security check REMOTE_ADDR for security require a special code for security, perhaps a list of TAN codes (such as banks use for online transactions) each which can only be used once, both the client and server have these I wonder if there is some kind of standard REST query I should lean on for e.g. building SQL-like statements in the URL parameters, e.g. http://www.thedatalayersite.com/query?insertinto=customers&... Any thoughts, notes from experience, ideas, gotchas, especially ideas on tightening down security in this endeavor would be helpful.

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  • How to query two tables based on whether or not record exists in a third?

    - by Katherine
    I have three tables, the first two fairly standard: 1) PRODUCTS table: pid pname, etc 2) CART table: cart_id cart_pid cart_orderid etc The third is designed to let people save products they buy and keep notes on them. 3) MYPRODUCTS table: myprod_id myprod_pid PRODUCTS.prod_id = CART.cart_prodid = MYPRODUCTS.myprod_pid When a user orders, they are presented with a list of products on their order, and can optionally add that product to myproducts. I am getting the info necessary for them to do this, with a query something like this for each order: SELECT cart.pid, products.pname, products.pid FROM products, cart WHERE products.pid = cart_prodid AND cart_orderid=orderid This is fine the first time they order. However, if they subsequently reorder a product which they have already added to myproducts, then it should NOT be possible for them to add it to myproducts again - basically instead of 'Add to MyProducts' they need to see 'View in MyProducts'. I am thinking I can separate the products using two queries: Products never added to MyProducts By somehow identifying whether the user has the product in MyProducts already, and if so excluding it from the query above. Products already in MyProducts By reversing the process above. I need some pointers on how to do this though.

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  • Storing Arbitrary Contact Information in Ruby on Rails

    - by Anthony Chivetta
    Hi, I am currently working on a Ruby on Rails app which will function in some ways like a site-specific social networking site. As part of this, each user on the site will have a profile where they can fill in their contact information (phone numbers, addresses, email addresses, employer, etc.). A simple solution to modeling this would be to have a database column per piece of information I allow users to enter. However, this seems arbitrary and limited. Further, to support allowing users to enter as many phone numbers as they would like requires the addition of another database table and joins. It seems to me that a better solution would be to serialize all the contact information entered by a user into a single field in their row. Since I will never be conditioning a SQL query on this information, such a solution wouldn't be any less efficient. Ideally, I would like to use a vCard as my serialization format. vCards are the standard solution to storing contact information across the web, and reusing tested solutions is a Good Thing. Alternative serialization formats would include simply marshaling a ruby hash, or YAML. Regardless of serialization format, supporting the reading and updating of this information in a rails-like way seems to be a major implementation challenge. So, here's the question: Has anyone seen this approach used in a rails application? Are there any rails plugins or gems that make such a system easy to implement? Ideally what I would like is an acts_as_vcard to add to my model object that would handle editing the vcard for me and saving it back to the database.

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  • Passing data to a non-static listBox, by calling function from another class

    - by Andrew A
    I have a simple forms program that I have been fighting with for a while now. I simply want to be able to call a method from a different class file (when a certain step is triggered in the code in that class file) in order to insert a string in the listBox. Here is my main method, pretty standard: class Program { [STAThread] static void Main(string[] args) { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new MainForm()); } } Here is the function which resides in my MainForm.cs file, which I can call just fine from that class file (via 'TextToBox(myString);'): public partial class MainForm : Form { ... // Function to output results to main Listbox window public void TextToBox(string aString) { // Place messages in Main Display list box window this.listBox1.Items.Insert(0, aString); } ... } But my problem is when I am in another class and I want to call 'TextToBox(myString);'. If I create another object reference of the MainForm, the code compiles fine but nothing will show up in the listBox. How do I do this? I cannot simply make TextToBox() static. I know I must create the object reference but I can't figure out how to reference the ORIGINAL MainForm, the one that was created in the Main method. Thanks in advance...

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  • Android: Unable to make httprequest behind firewall

    - by Yang
    The standard getUrlContent works welll when there is no firewall. But I got exceptions when I try to do it behind a firewall. I've tried to set "http proxy server" in AVD manager, but it didn't work. Any idea how to correctly set it up? protected static synchronized String getUrlContent(String url) throws ApiException { if(url.equals("try")){ return "thanks"; } if (sUserAgent == null) { throw new ApiException("User-Agent string must be prepared"); } // Create client and set our specific user-agent string HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(url); request.setHeader("User-Agent", sUserAgent); try { HttpResponse response = client.execute(request); // Check if server response is valid StatusLine status = response.getStatusLine(); if (status.getStatusCode() != HTTP_STATUS_OK) { throw new ApiException("Invalid response from server: " + status.toString()); } // Pull content stream from response HttpEntity entity = response.getEntity(); InputStream inputStream = entity.getContent(); ByteArrayOutputStream content = new ByteArrayOutputStream(); // Read response into a buffered stream int readBytes = 0; while ((readBytes = inputStream.read(sBuffer)) != -1) { content.write(sBuffer, 0, readBytes); } // Return result from buffered stream return new String(content.toByteArray()); } catch (IOException e) { throw new ApiException("Problem communicating with API", e); } }

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  • Changing CSS height property removes anchors?

    - by JMan
    I am working on a standard header/navigation for my website. I started with having a CSS "height" value of 100% for the html, body elements but this resulted in the wrong layout. However, when I change the CSS height property from "100%" to "auto", the layout is correct, but I lose the anchors in the navigation. Why is this? Here's my CSS: html,body { height: auto; /* This is the only property that I'm toggling */ margin: 0; } body { margin: 0; min-width: 978px; font: 12px/16px Arial, Helvetica, sans-serif; color: #000; background: #000001 url('../images/bg-body.jpg') no-repeat 50% 0; } #nav { position: relative; float: left; margin: 0; padding: 0 2px 0 271px; list-style: none; background: url('../images/sep-nav.gif') no-repeat 100% 0; } #nav li { float: left; padding: 11px 0 0 2px; height: 35px; width: 128px; line-height: 22px; font-size: 18px; text-align: center; background: url('../images/sep-nav.gif') no-repeat 0 -1px; display: inline; } #nav li a {color: #FFFEFE;} ..... I compared the computed CSS in Firebug when the html, body height property was set to "auto" vs. "100%" and they were the same. Can somebody please shed some light on how retain the anchors in the navigation while setting height to "auto"? Thanks for your help.

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  • Zend Layout and Bootstrapping

    - by emeraldjava
    So i'm using the standard Zend Layout for my site. I have a number of custom controllers and views, and the content of these pages is displayed, but the details in the head element of the layout.phtml are not shown. Do i need to manually associate the Zend_Layout with each specific controller?. I expected since the layout is loaded via the bootstrap this should be available for free. My app.ini file has # layout resources.layout.layoutPath = APPLICATION_PATH "/layouts/scripts" resources.layout.layout = "layout" #resources.view[] = # Views resources.view.encoding = "UTF-8" resources.view.basePath = APPLICATION_PATH "/views/" my layout.phtml <?php echo $this->doctype() ?> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <?php echo $this->headTitle() ?> <?php echo $this->jQuery();?> </head> <!-- application/layouts/scripts/layout.phtml --> <body> <div id="content"> <?php echo $this->layout()->content ?> </div> </body>

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  • Where to put a textfile I want to use in eclipse?

    - by Jayomat
    hi there, I need to read a text file when I start my program. I'm using eclipse and started a new java project. In my project folder I got the "src" folder and the standard "JRE System Library"... I just don't know where to put the text file. I cannot use a "hard coded" path because the text file needs to be included with my app... I also tried to create a new folder like "Files" and use the pathe "Files/staedteliste.txt".. doesn't work too... I use the following code to read the file, but I get this error: Error:java.io.FileNotFoundException:staedteliste.txt(No such file or directory) import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; public class Test { ArrayList<String[]> values; public static void main(String[] args) { // TODO Auto-generated method stub loadList(); } public static void loadList() { BufferedReader reader; String zeile = null; try { reader = new BufferedReader(new FileReader("staedteliste.txt")); zeile = reader.readLine(); ArrayList<String[]> values = new ArrayList<String[]>(); while (zeile != null) { values.add(zeile.split(";")); zeile = reader.readLine(); } System.out.println(values.size()); System.out.println(zeile); } catch (IOException e) { System.err.println("Error :"+e); } } } thx for help!

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  • How do I import and call unmanaged C dll with ansi string "char *" pointer string from VB.net?

    - by Warren P
    I have written my own function, which in C would be declared like this, using standard Win32 calling conventions: int Thing( char * command, char * buffer, int * BufSize); I have the following amount of VB figured out, which should import the dll and call this function, wrapping it up to make it easy to call Thing("CommandHere",GetDataBackHere): Imports Microsoft.VisualBasic Imports System.Runtime.InteropServices Imports System Imports System.Text Namespace dllInvocationSpace Public Class dllInvoker ' tried attributes but could not make it build: ' <DllImport("Thing1.dll", False, CallingConvention.Cdecl, CharSet.Ansi, "Baton", True, True, False, True)> Declare Ansi Function Thing Lib "Thing1.dll" (ByVal Command As String, ByRef Buffer As String, ByRef BufferLength As Integer) Shared Function dllCall(ByVal Command As String, ByRef Results As String) As Integer Dim Buffer As StringBuilder = New StringBuilder(65536) Dim retCode As Integer Dim bufsz As Integer bufsz = 65536 retCode = Thing(Command, Buffer, bufsz) Results = Buffer Return retCode End Function End Class End Namespace The current code doesn't build, because although I think I should be able to create a "buffer" that the C Dll can write data back into using a string builder, I haven't got it quite right. (Value of type System.Text.STringBuilder cannot be converted to 'String'). I have looked all over the newsgroups and forums and can not find an example where the C dll needs to pass between 1 and 64kbytes of data back (char *buffer, int bufferlen) to visual basic.net.

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  • Is there a library that can decompile a method into an Expression tree, with support for CLR 4.0?

    - by Daniel Earwicker
    Previous questions have asked if it is possible to turn compiled delegates into expression trees, for example: http://stackoverflow.com/questions/767733/converting-a-net-funct-to-a-net-expressionfunct The sane answers at the time were: It's possible, but very hard and there's no standard library solution. Use Reflector! But fortunately there are some greatly-insane/insanely-great people out there who like reverse engineering things, and they make difficult things easy for the rest of us. Clearly it is possible to decompile IL to C#, as Reflector does it, and so you could in principle instead target CLR 4.0 expression trees with support for all statement types. This is interesting because it wouldn't matter if the compiler's built-in special support for Expression<> lambdas is never extended to support building statement expression trees in the compiler. A library solution could fill the gap. We would then have a high-level starting point for writing aspect-like manipulations of code without having to mess with raw IL. As noted in the answers to the above linked question, there are some promising signs but I haven't succeeded in finding if there's been much progress since by searching. So has anyone finished this job, or got very far with it? Note: CLR 4.0 is now released. Time for another look-see.

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  • Why did this work with Visual C++, but not with gcc?

    - by Carlos Nunez
    I've been working on a senior project for the last several months now, and a major sticking point in our team's development process has been dealing wtih rifts between Visual-C++ and gcc. (Yes, I know we all should have had the same development environment.) Things are about finished up at this point, but I ran into a moderate bug just today that had me wondering whether Visual-C++ is easier on newbies (like me) by design. In one of my headers, there is a function that relies on strtok to chop up a string, do some comparisons and return a string with a similar format. It works a little something like the following: int main() { string a, b, c; //Do stuff with a and b. c = get_string(a,b); } string get_string(string a, string b) { const char * a_ch, b_ch; a_ch = strtok(a.c_str(),","); b_ch = strtok(b.c_str(),","); } strtok is infamous for being great at tokenizing, but equally great at destroying the original string to be tokenized. Thus, when I compiled this with gcc and tried to do anything with a or b, I got unexpected behavior, since the separator used was completely removed in the string. Here's an example in case I'm unclear; if I set a = "Jim,Bob,Mary" and b="Grace,Soo,Hyun", they would be defined as a="JimBobMary" and b="GraceSooHyun" instead of staying the same like I wanted. However, when I compiled this under Visual C++, I got back the original strings and the program executed fine. I tried dynamically allocating memory to the strings and copying them the "standard" way, but the only way that worked was using malloc() and free(), which I hear is discouraged in C++. While I'm curious about that, the real question I have is this: Why did the program work when compiled in VC++, but not with gcc? (This is one of many conflicts that I experienced while trying to make the code cross-platform.) Thanks in advance! -Carlos Nunez

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  • Call WCF Service Through Javascript, AJAX, or JQuery

    - by obautista
    I created a number of standard WCF Services (Service Contract and Host (svc) are in separate assemblies). I fired up a Web Site in IIS to host the Services (i.e., address is http://services:1000/wcfservices.svc). Then in my Web Site project I added the reference. I am able to call the services normally. I am needed to call some of the services client side. Not sure if I should be looking at articles calling WCF services through AJAX, JQuery, or JSON enabled WCF Services. Can anyone provide any thoughts or experience with configuring as such? Some of the changes I made was adding the following to the Operation Contract: [OperationContract] [WebInvoke(Method = "POST", UriTemplate = "SetFoo")] void SetFoo(string Id); Then this above the implementation of the interface: [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] Then in the service webconfig I have this (parens are angle brackets): <serviceHostingEnvironment aspNetCompatibilityEnabled="true"> <baseAddressPrefixFilters> <add prefix="http://services:1000/wcfservices.svc/"/>> </baseAddressPrefixFilters> </serviceHostingEnvironment> <serviceHostingEnvironment multipleSiteBindingsEnabled="false" /> Then in the client side I attempted this: <asp:ScriptManagerProxy ID="ScriptManagerProxy1" runat="server"> <compositeScript> <Scripts> <asp:ScriptReference Path="http://Flixsit:1000/FlixsitWebServices.svc" /> </Scripts> </CompositeScript> </asp:ScriptManagerProxy> I am attempting to call the service like this in javascript: wcfservices.SetFoo(string Id); Nothing is working. If it is idea or a better solution to call JSON enable, JQuery, etc....I am willing to make any changes. Thanks for any suggestions/tips provided....

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  • What's the best way to read a UDT from a database with Java?

    - by Lukas Eder
    I thought I knew everything about UDTs and JDBC until someone on SO pointed out some details of the Javadoc of java.sql.SQLInput and java.sql.SQLData JavaDoc to me. The essence of that hint was (from SQLInput): An input stream that contains a stream of values representing an instance of an SQL structured type or an SQL distinct type. This interface, used only for custom mapping, is used by the driver behind the scenes, and a programmer never directly invokes SQLInput methods. This is quite the opposite of what I am used to do (which is also used and stable in productive systems, when used with the Oracle JDBC driver): Implement SQLData and provide this implementation in a custom mapping to ResultSet.getObject(int index, Map mapping) The JDBC driver will then call-back on my custom type using the SQLData.readSQL(SQLInput stream, String typeName) method. I implement this method and read each field from the SQLInput stream. In the end, getObject() will return a correctly initialised instance of my SQLData implementation holding all data from the UDT. To me, this seems like the perfect way to implement such a custom mapping. Good reasons for going this way: I can use the standard API, instead of using vendor-specific classes such as oracle.sql.STRUCT, etc. I can generate source code from my UDTs, with appropriate getters/setters and other properties My questions: What do you think about my approach, implementing SQLData? Is it viable, even if the Javadoc states otherwise? What other ways of reading UDT's in Java do you know of? E.g. what does Spring do? what does Hibernate do? What does JPA do? What do you do? Addendum: UDT support and integration with stored procedures is one of the major features of jOOQ. jOOQ aims at hiding the more complex "JDBC facts" from client code, without hiding the underlying database architecture. If you have similar questions like the above, jOOQ might provide an answer to you.

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  • Complex derived attributes in Django models

    - by rabidpebble
    What I want to do is implement submission scoring for a site with users voting on the content, much like in e.g. reddit (see the 'hot' function in http://code.reddit.com/browser/sql/functions.sql). My submission model currently keeps track of up and down vote totals. Currently, when a user votes I create and save a related Vote object and then use F() expressions to update the Submission object's voting totals. The problem is that I want to update the score for the submission at the same time, but F() expressions are limited to only simple operations (it's missing support for log(), date_part(), sign() etc.) From my limited experience with Django I can see 4 options here: extend F() somehow (haven't looked at the code yet) to support the missing SQL functions; this is my preferred option and seems to fit within the Django framework the best define a scoring function (much like reddit's 'hot' function) in my database, and have Django use the value of that function for the value of the score field; as far as I can tell, #2 is not possible wrap my two step voting process in a suitably isolated transaction so that I can calculate the voting totals in Python and then update the Submission's voting totals without fear that another vote against the submission could be added/changed in the meantime; I'm hesitant to take this route because it seems overly complex - what is a "suitably isolated transaction" in this case anyway? use raw SQL; I would prefer to avoid this entirely -- what's the point of an ORM if I have to revert to SQL for such a common use case as this! (Note that this coming from somebody who loves sprocs, but is using Django for ease of development.) Before I embark on this mission to extend F() (which I'm not sure is even possible), am I about to reinvent the wheel? Is there a more standard way to do this? It seems like such a common use case and yet in an hour of searching I have yet to find a common solution...

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  • efficiently determining if a polynomial has a root in the interval [0,T]

    - by user168715
    I have polynomials of nontrivial degree (4+) and need to robustly and efficiently determine whether or not they have a root in the interval [0,T]. The precise location or number of roots don't concern me, I just need to know if there is at least one. Right now I'm using interval arithmetic as a quick check to see if I can prove that no roots can exist. If I can't, I'm using Jenkins-Traub to solve for all of the polynomial roots. This is obviously inefficient since it's checking for all real roots and finding their exact positions, information I don't end up needing. Is there a standard algorithm I should be using? If not, are there any other efficient checks I could do before doing a full Jenkins-Traub solve for all roots? For example, one optimization I could do is to check if my polynomial f(t) has the same sign at 0 and T. If not, there is obviously a root in the interval. If so, I can solve for the roots of f'(t) and evaluate f at all roots of f' in the interval [0,T]. f(t) has no root in that interval if and only if all of these evaluations have the same sign as f(0) and f(T). This reduces the degree of the polynomial I have to root-find by one. Not a huge optimization, but perhaps better than nothing.

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  • Troubleshooting failover cluster problem in W2K8 / SQL05

    - by paulland
    I have an active/passive W2K8 (64) cluster pair, running SQL05 Standard. Shared storage is on a HP EVA SAN (FC). I recently expanded the filesystem on the active node for a database, adding a drive designation. The shared storage drives are designated as F:, I:, J:, L: and X:, with SQL filesystems on the first 4 and X: used for a backup destination. Last night, as part of a validation process (the passive node had been offline for maintenance), I moved the SQL instance to the other cluster node. The database in question immediately moved to Suspect status. Review of the system logs showed that the database would not load because the file "K:\SQLDATA\whatever.ndf" could not be found. (Note that we do not have a K: drive designation.) A review of the J: storage drive showed zero contents -- nothing -- this is where "whatever.ndf" should have been. Hmm, I thought. Problem with the server. I'll just move SQL back to the other server and figure out what's wrong.. Still no database. Suspect. Uh-oh. "Whatever.ndf" had gone into the bit bucket. I finally decided to just restore from the backup (which had been taken immediately before the validation test), so nothing was lost but a few hours of sleep. The question: (1) Why did the passive node think the whatever.ndf files were supposed to go to drive "K:", when this drive didn't exist as a resource on the active node? (2) How can I get the cluster nodes "re-syncd" so that failover can be accomplished? I don't know that there wasn't a "K:" drive as a cluster resource at some time in the past, but I do know that this drive did not exist on the original cluster at the time of resource move.

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