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  • Multiple Exception Handling in one if statement [closed]

    - by JA3N
    I am having trouble with throwing and catching exceptions. Here is the code for assignSeat(), assignSeat is called in a try block in another class. void assignSeat(String passengerName, int x, int y) throws SeatOccupiedException, InvalidPassengerNameException { Seat tSeat = airplane.getSeat(x,y); if (tSeat!=null) { if (passengerName.isEmpty() || !passengerName.matches("[a-zA-Z]+")) { throw new InvalidPassengerNameException(); } //excluded else if else if (foundPassenger(passengerName)) { airplane.seatList.get(airplane.seatNumber(passengerName)).unOccupy(); tSeat.occupy(); for (int i = 0; i<passengers.size();i++) if (passengers.get(i).getName().equals(passengerName)) passengers.get(i).changeSeat(tSeat.getSeatName()); } else if (!tSeat.occupied) { tSeat.occupy(); addPassenger(passengerName, tSeat.getSeatName()); } else if (tSeat.occupied) { throw new SeatOccupiedException(); } } and here is the code that calls assignSeat() and is in another class (I won't copy the whole class to make it look clearer) if (afComp.currentAF != null) { try { afComp.currentAF.assignSeat(nameField.getText(), x, y); //<-Problem here, "Unhandled exception type SeatOccupiedException" } catch (SeatOccupiedException exception) //<-Problem here, "Unreachable catch block, This exception is never thrown from the try statement body" { } catch(InvalidPassengerNameException exception) //<-No problems. { } } Whats wrong with the try block? why won't it throw the SeatOccupiedException? Exception classes: SeatOccupied: package a2; public class SeatOccupiedException extends Exception { public SeatOccupiedException(){} } InvalidPassengerName: package a2; public class InvalidPassengerNameException extends Exception { public InvalidPassengerNameException() {} } Every class I have is in package a2 imports for class that calls assignSeat package a2; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import java.awt.event.MouseEvent; import java.awt.BorderLayout; import javax.swing.*; import javax.swing.event.*; imports for class that has assignSeat package a2; import java.util.ArrayList;

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  • OSX launchctl programmatically as root

    - by Lukas1
    I'm trying to start samba service using launchctl from OSX app as root, but I get error status -60031. I can run without problems the command in Terminal: sudo launchctl load -F /System/Library/LaunchDaemons/com.apple.AppleFileServer.plist` In the objective-c code, I'm using (I know it's deprecated, but that really shouldn't be the issue here) AuthorizationExecuteWithPrivileges method. Here's the code: NSString *command = @"launchctl"; // Conversion of NSArray args to char** args here (not relevant part of the code) OSStatus authStatus = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &_authRef); if (authStatus != errAuthorizationSuccess) { NSLog(@"Failed to create application authorization: %d", (int)authStatus); return; } FILE* pipe = NULL; AuthorizationFlags flags = kAuthorizationFlagDefaults; AuthorizationItem right = {kAuthorizationRightExecute, 0, NULL, 0}; AuthorizationRights rights = {1, &right}; // Call AuthorizationCopyRights to determine or extend the allowable rights. OSStatus stat = AuthorizationCopyRights(_authRef, &rights, NULL, flags, NULL); if (stat != errAuthorizationSuccess) { NSLog(@"Copy Rights Unsuccessful: %d", (int)stat); return; } OSStatus status = AuthorizationExecuteWithPrivileges(_authRef, command.UTF8String, flags, args, &pipe); if (status != errAuthorizationSuccess) { NSLog(@"Error executing command %@ with status %d", command, status); } else { // some other stuff } I have also tried using different flags then kAuthorizationFlagDefaults, but that led to either the same problem or error code -60011 - invalid flags. What am I doing wrong here, please?

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  • Best (Java) book for understanding 'under the bonnet' for programming?

    - by Ben
    What would you say is the best book to buy to understand exactly how programming works under the hood in order to increase performance? I've coded in assembly at university, I studied computer architecture and I obviously did high level programming, but what I really dont understand is things like: -what is happening when I perform a cast -whats the difference in performance if I declare something global as opposed to local? -How does the memory layout for an ArrayList compare with a Vector or LinkedList? -Whats the overhead with pointers? -Are locks more efficient than using synchronized? -Would creating my own array using int[] be faster than using ArrayList -Advantages/disadvantages of declaring a variable volatile I have got a copy of Java Performance Tuning but it doesnt go down very low and it contains rather obvious things like suggesting a hashmap instead of using an ArrayList as you can map the keys to memory addresses etc. I want something a bit more Computer Sciencey, linking the programming language to what happens with the assembler/hardware. The reason im asking is that I have an interview coming up for a job in High Frequency Trading and everything has to be as efficient as possible, yet I cant remember every single possible efficiency saving so i'd just like to learn the fundamentals. Thanks in advance

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  • writing something in jList

    - by bigbluedragon
    hey i have another problem. I created jList in my main window and now i want to add something to it. I do it this way... private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) { Dodaj_Przedmiot dodaj_przedmiot = new Dodaj_Przedmiot(null, true); dodaj_przedmiot.setVisible(true); SterowanieBazy instance = SterowanieBazy.getInstance(); Zmienne_pomocnicze zp = new Zmienne_pomocnicze(); instance.dodajPrzedmiot(przedmiot); String przedm[] = instance.zwrocPrzedmioty(); jList1.setListData(przedm); } what i want to write in that list is what i collect from my jDialogForm: dodaj_przedmiot private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { String sciezka = jTextField1.getText(); if (sciezka.length() > 0) { Zmienne_pomocnicze zp = new Zmienne_pomocnicze(); zp.setPrzechowaj(sciezka); } this.setVisible(false); } and i collect try to copy that date using this class public class Zmienne_pomocnicze { public String n; public int a; public void setPrzechowaj (String neew) { n = neew; } public String getPrzechowaj () { return n; } } i would be grateful for any ideas how to make it works^^

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  • Problems with video conversions through the web (local host)

    - by ron-d
    Hello, I get the following errors when I attempt video format conversions called from the local host: “An invalid media type was specified” for M4V to WMV conversions. “One or more arguments are invalid” for MP4 to WMV conversions. Here are the details of the problems: I’ve written a dll in C# that accepts videos in the formats AVI, WMV, M4V and MP4 and performs the following actions: Creates a copy of the input video in WMV format . Creates a WAV file of the input video audio portion. Creates a JPG image from a frame of the input video. I attached the dll to an ASP.NET web project that performs the dll actions. When tested through the developer studio, the actions are performed as intended for all formats. When I place the web project in place to be read when the local host is called through the web browser, the following behavior takes place: WMV format: All actions performed as intended. AVI format: Creates WMV file – OK Creates JPG image – OK Creates empty WAV file – problem. M4V format: Creates empty WAV file – problem. Does not create WMV file -problem Does not create JPG file –problem Throws me the error “An invalid media type was specified” MP4 format: Creates empty WAV file – problem. Does not create WMV file -problem Does not create JPG file –problem Throws me the error “One or more arguments are invalid” When I check their security property, all the files have the same permission access parameters (when I check their security property. Can anyone guide me as to how to solve these problems when the web project is called from the local host? Thank you.

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  • Google App Engine error Object Manager has been closed

    - by newbie
    I had following error from Google App Engine when I was trying to iterate list in JSP page with EL. Object Manager has been closed I solved problem with following coe, but I don't think that it is very good solution to this problem: public List<Item> getItems() { PersistenceManager pm = getPersistenceManager(); Query query = pm.newQuery("select from " + Item.class.getName()); List<Item> items = (List<Items>) query.execute(); List<Item> items2 = new ArrayList<Item>(); // This line solved my problem Collections.copy(items, items2); // and this also pm.close(); return (List<Item>) items; } When I tried to use pm.detachCopyAll(items) it gave same error. I understood that detachCopyAll() method should do same what I did, but that method should be part of data nucelus, so it should be used instead of my owm methods. So why dosen't detachCopyAll() work at all?

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  • What's a good way to write batch scripts in C#?

    - by Scott Bilas
    I would like to write simple scripts in C#. Stuff I would normally use .bat or 4NT .btm files for. Copying files, parsing text, asking user input, and so on. Fairly simple but doing this stuff right in a batch file is really hard (no exceptions for example). I'm familiar with command line "scripting" wrappers like AxScript so that gets me part of the way there. What I'm missing is the easy file-manipulation framework. I want to be able to do cd(".."), copy(srcFile, destFile) type functionality. Tools I have tried: NANT, which we use in our build process. Not a good scripting tool. Insanely verbose XML syntax and to add a simple function you must write an extension assembly. Can't do it inline. PowerShell. Looks great, but I just haven't been able to switch over to this as my primary shell. Too many differences from 4NT. Whatever I do needs to run from an ordinary command prompt and not require a special shell to run it through. Can PowerShell be used as a script executor? Perl/Python/Ruby. Really hate learning an entirely new language and framework just to do batch file operations. Haven't been able to dedicate the time I need to do this. Plus, we're a 99% .NET shop for our toolchain and I really want to leverage our existing experience and codebase. Are there frameworks out there that are trying to solve this problem of "make a batch file in C#" that you have used? I want the power of C#/.NET with the immediate-mode type functionality of a typical cmd.exe shell language. Am I alone in wanting something like this?

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  • jquery question

    - by OM The Eternity
    I am using the Jquery library to copy the text enter in one textfield to another textfield using a check box when clicked.. which is as follows <html> <head> <script src="js/jquery.js" ></script> </head> <body> <form> <input type="text" name="startdate" id="startdate" value=""/> <input type="text" name="enddate" id="enddate" value=""/> <input type="checkbox" name="checker" id="checker" /> </form> <script> $(document).ready(function(){ $("input#checker").bind("click",function(o){ if($("input#checker:checked").length){ $("#enddate").val($("#startdate").val()); }else{ $("#enddate").val(""); } }); } ); </script> </body> </html> now here i want the check box to be selected by default, so that the data entered in start date get copied automatically as check box is checked by default... so what event should be called here in jquery script? please help me in resolving this issue...

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  • NHibernate / multiple sessions and nested objects

    - by bernhardrusch
    We are using NHibernate in a rich client application. It is a pretty open application (the user searches for a dataset or creates a new one, changes the data and saves the data set. We leave the session open, because sometimes we have to lazy load some properties of the object (nested object structure). This means one big problem if we leave the session open, the db (MySQL) closes the connection and we are not able to find this out and it throws an exception (socket communication error) when accessing the database (we are thinking about testing the db connection before accessing the object - but this is not really optimal neither, the other option would be to set back the timeout of the db connection , but this just doesn't seem to well). So - is it possible to reconnect the session to a new database connection ? Another problem is it possible to get an object from one session and then re-attach it to another session ? (I often hear that session.lock should work for this - but this doesn't work so well in our application - so I ended up getting a "fresh" object from the session and copy the data over manually - which is a little bit cumbersome) Any ideas for this ?

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  • C: incompatible types in assignment

    - by The.Anti.9
    I'm writing a program to check to see if a port is open in C. One line in particular copies one of the arguments to a char array. However, when I try to compile, it says: error: incompatible types in assignment Heres the code. The error is on the assignment of addr #include <sys/socket.h> #include <sys/time.h> #include <sys/types.h> #include <arpa/inet.h> #include <netinet/in.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <netdb.h> #include <stdlib.h> #include <string.h> #include <unistd.h> int main(int argc, char **argv) { u_short port; /* user specified port number */ char addr[1023]; /* will be a copy of the address entered by u */ struct sockaddr_in address; /* the libc network address data structure */ short int sock = -1; /* file descriptor for the network socket */ port = atoi(argv[1]); addr = strncpy(addr, argv[2], 1023); bzero((char *)&address, sizeof(address)); /* init addr struct */ address.sin_addr.s_addr = inet_addr(addr); /* assign the address */ address.sin_port = htons(port); /* translate int2port num */ sock = socket(AF_INET, SOCK_STREAM, 0); if (connect(sock,(struct sockaddr *)&address,sizeof(address)) == 0) { printf("%i is open\n", port); } if (errno == 113) { fprintf(stderr, "Port not open!\n"); } close(sock); return 0; } I'm new to C, so I'm not sure why it would do this.

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  • HTML table manipulation using jQuery

    - by Daniel
    I'm building a site using CakePHP and am currently working on adding data to two separate tables at the same time.. not a problem. The problem I have is that I'm looking to dynamically alter the form that accepts the input values, allowing the click of a button/link to add an additional row of form fields. At the moment I have a table that looks something like this: <table> <thead> <tr> <th>Campus</th> <th>Code</th> </tr> </thead> <tbody> <tr> <td> <select id="FulltimeCourseCampusCode0CampusId" name="data[FulltimeCourseCampusCode][0][campus_id]"> <option value=""></option> <option value="1">Evesham</option> <option value="2">Malvern</option> </select> </td> <td> <input type="text" id="FulltimeCourseCampusCode0CourseCode" name="data[FulltimeCourseCampusCode][0][course_code]"> </td> </tr> </tbody> What I need is for the row within the tbody tag to be replicated, with the minor change of having all the zeros (i.e. such as here FulltimeCourseCampusCode0CampusId and here data[FulltimeCourseCampusCode][0][campus_id]) incremented. I'm very new to jQuery, having done a few minor bits, but nothing this advanced (mostly just copy/paste stuff). Can anyone help? Thank you.

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  • Problems with i18n using django translation on App-Engine with Korean and Hindi

    - by Greg
    I've got a setup based on the post here, and it works perfectly. Adding more languages to the mix, it recognises them fine, except for Korean (ko) and Hindi (hi). Chinese/Japanese/Hebrew are all fine, so nothing to do with encodings/charsets I don't think. Taking a look into the django code inside the app-engine SDK, I notice that all the languages that I'm using except for ko and hi are ones that ship with django - in the default settings.py and inside the locale folder they are missing. If I copy one of the locale folders inside the /usr/local/google_appengine/lib/django[...]/conf/locale and rename it to be 'ko', then it starts working in my app, but I won't be able to replicate this modification when I deploy to app-engine, so need a bit of help understanding what I might be doing wrong. my settings.py is definitely being taken into account, as if I remove languages from there then they stop working (as they should). If I copied the django modules into my app, under 'lib' there say, could I use those instead of the ones app-engine tries to use, maybe? I'm brand new to python/django/app-engine, and developing on a Mac with Leopard, if that makes any difference. I have the latest app-engine SDK as of tuesday.

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  • PHP sql with foreach loop variable problem

    - by anthony
    This is really getting frustrating. I have a text file that I'm reading for a list of part numbers that goes into an array. I'm using the following foreach function to search a database for matching numbers. $file = file('parts_array.txt'); foreach ($file as $newPart) { $sql = "SELECT products_sku FROM products WHERE products_sku='" . $newPart . "'"; $rs = mysql_query($sql); $num_rows = mysql_num_rows($rs); echo $num_rows; echo "<br />"; } The problem is I'm getting 0 rows returned from mysql_num_rows. I can type the sql statement without the variable and it works perfectly. I can even echo out the sql statement from this script, copy and paste the statement from the browser and it works. But, for some reason I'm not getting any records when I'm using the variable. I've used variables in sql statements tons of times, but this really has me stumped.

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  • Unreasonable errors in merge sort

    - by Alexxx
    i have the following errors - please help me to find the error: 9 IntelliSense: expected a '}' 70 4 it points on the end of the code - but there are no open { anywhere!! so why?? 8 IntelliSense: expected a ';' 57 1 it points on the { after the void main but why to put ; after the { of the void main?? Error 7 error C1075: end of file found before the left brace '{' at 70 1 points to the beginig of the code - why??? #include <stdio.h> #include <stdlib.h> void merge(int *a,int p,int q,int r) { int i=p,j=q+1,k=0; int* temp=(int*)calloc(r-p+1, sizeof(int)); while ((i<=q)&& (j<=r)) if(a[i]<a[j]) temp[k++]=a[i++]; else temp[k++]=a[j++]; while(j<=r) // if( i>q ) temp[k++]=a[j++]; while(i<=q) // j>r temp[k++]=a[i++]; for(i=p,k=0;i<=r;i++,k++) // copy temp[] to a[] a[i]=temp[k]; free(temp); } void merge_sort(int *a,int first, int last) { int middle; if(first < last) { middle=(first+last)/2; merge_sort(a,first,middle); merge_sort(a,middle+1,last); merge(a,first,middle,last); { } void main() { int a[] = {9, 7, 2, 3, 5, 4, 1, 8, 6, 10}; int i; merge_sort(a, 0, 9); for (i = 0; i < 10; i++) printf ("%d ", a[i]);

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  • Problem shrinking with StretchBlt()

    - by SparkyNZ
    Hi. I have some code that paints my own rectangular buttons based on a source bitmap. Most of the time the destination buttons are bigger than my source bitmap image and StretchBlt works fine. However, when the destination is smaller than the source image, StretchBlt refuses to fill the entire destination area. I know StretchBlt isn't great on quality when it comes to scaling down images but I'm not too concerned about that. I just don't want missing pixels. Here a link with the source image at the top and destination at the bottom: link text Note, I am actually shrinking parts of the source image into the destination. I am not shrinking the entire image down. So for example, I copy the corners size for size with BitBlt() then I stretch (squash) the horizontal pixel data between the corners from the source image into the destination DC. There is no fault with my source and destination coordinates. If I change from SRCCOPY to WHITENESS, the entire area fills with white as you'd expect. There is no grey bar where pixels haven't copied as you see in the Broken.bmp image above. Has anyone had this problem before, and if so, can somebody please suggest a solution? Cheers

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  • Using Mercurial (hg), can you just "hg backout" all the commits you did for the files you don't want

    - by Jian Lin
    Using Mercurial (hg), can you just "hg backout" all the commits you did for the files you don't want to push, and then do a push? Because Mercurial (or Git) won't let us push a single file or a single folder to another repository, so I am thinking: 1) How about, we just look at the commit we did, and hg backout the ones we don't want to push. 2) hg out -v to see the list of files that will be pushed 3) now do the push by hg push Is this a good way? This is because I got the following advice: 1) Don't commit that file if you don't want it to be pushed (but sometimes even just for experimentation, I do want to keep the intermediate revisions) (-- maybe I can hg commit and hg backout right away to prevent it from being pushed.) 2) Some people told me just to hg clone tmp from that repository i want to push to, and then copy the local file over to this tmp working directory, hg commit to this tmp repository, and then do a push. But I found that the hg clone tmp will take up 400MB of new data and files, and make the hard drive work very hard, just to push 1 file? So I would rather not use this method.

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  • How do I fix the alpha value after calling GDI text functions?

    - by Daniel Stutzbach
    I have a application that uses the Aero glass effect, so each pixel has an alpha value in addition to red, green, and blue values. I have one custom-draw control that has a solid white background (alpha = 255). I would like to draw solid text on the control using the GDI text functions. However, these functions set the alpha value to an arbitrary value, causing the text to translucently show whatever window is beneath my application's. After calling rendering the text, I would like to go through all of the pixels in the control and set their alpha value back to 255. What's the best way to do that? I haven't had any luck with the BitBlt, GetPixel, and SetPixel functions. They appear to be oblivious to the alpha value. Here are other solutions that I have considered and rejected: Draw to a bitmap, then copy the bitmap to the device: With this approach, the text rendering does not make use of the characteristics of the monitor (e.g., ClearText). Use GDI+ for text rendering: This application originally used GDI+ for text rendering (before I started working on Aero support). I switched to GDI because of difficulties I encountered trying to accurately measure strings with GDI+. I'd rather not switch back. Set the Aero region to avoid the control in question: My application's window is actually a child window of a different application running in a different process. I don't have direct control over the Aero settings on the top-level window. The application is written in C# using Windows Forms, though I'm not above using Interop to call Win32 API functions.

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  • multiple-to-one relationship mysql, submissions

    - by Yulia
    Hello, I have the following problem. Basically I have a form with an option to submit up to 3 images. Right now, after each submission it creates 3 records for album table and 3 records for images. I need it to be one record for album and 3 for images, plus to link images to the album. I hope it all makes sense... Here is my structure. TABLE `albums` ( `id` int(11) NOT NULL auto_increment, `title` varchar(50) NOT NULL, `fullname` varchar(40) NOT NULL, `email` varchar(100) NOT NULL, `created_at` datetime NOT NULL, `theme_id` int(11) NOT NULL, `description` int(11) NOT NULL, `vote_cache` int(11) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=20 ; TABLE `images` ( `id` int(11) NOT NULL auto_increment, `album_id` int(11) NOT NULL, `name` varchar(30) NOT NULL, and my code function create_album($params) { db_connect(); $query = sprintf("INSERT INTO albums set albums.title = '%s', albums.email = '%s', albums.discuss_url = '%s', albums.theme_id = '%s', albums.fullname = '%s', albums.description = '%s', created_at = NOW()", mysql_real_escape_string($params['title']), mysql_real_escape_string($params['email']), mysql_real_escape_string($params['theme_id']), mysql_real_escape_string($params['fullname']), mysql_real_escape_string($params['description']) ); $result = mysql_query($query); if(!$result) { return false; } $album_id = mysql_insert_id(); return $album_id; } if(!is_uploaded_file($_FILES['userfile']['tmp_name'][$i])) { $warning = 'No file uploaded'; } elseif is_valid_file_size($_FILES['userfile']['size'][$i])) { $_POST['album']['theme_id'] = $theme['id']; create_album($_POST['album']); mysql_query("INSERT INTO images(name) VALUES('$newName')"); copy($_FILES['userfile']['tmp_name'][$i], './photos/'.$original_dir.'/' .$newName.'.jpg');

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  • How to cast C struct just another struct type if their memory size are equal?

    - by Eonil
    I have 2 matrix structs means equal data but have different form like these: // Matrix type 1. typedef float Scalar; typedef struct { Scalar e[4]; } Vector; typedef struct { Vector e[4]; } Matrix; // Matrix type 2 (you may know this if you're iPhone developer) struct CATransform3D { CGFloat m11, m12, m13, m14; CGFloat m21, m22, m23, m24; CGFloat m31, m32, m33, m34; CGFloat m41, m42, m43, m44; }; typedef struct CATransform3D CATransform3D; Their memory size are equal. So I believe there is a way to convert these types without any pointer operations or copy like this: // Implemented from external lib. CATransform3D CATransform3DMakeScale (CGFloat sx, CGFloat sy, CGFloat sz); Matrix m = (Matrix)CATransform3DMakeScale ( 1, 2, 3 ); Is this possible? Currently compiler prints an "error: conversion to non-scalar type requested" message.

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  • Ruby on Rails: Uploading a modifed site.

    - by Califer
    I'm having a heck of a time getting a site I modified to work correctly. I didn't set the site up originally, and since the person that set it up no longer works with me I had to learn ruby just to make some changes. I made all the changes in the development server and everything worked fine. Then I did a diff on the production and development and moved only my changes over. Unfortunately when I loaded my changes onto the production server I got a lot of errors. I've changed all of the permissions to 755, which took care being able to access anything at all, but after that I started getting a lot of 500 errors. Nothing showed up in the production.log file. I really have no clue what's going wrong except that perhaps things are not noticing the new changes. I moved the old site to a backup folder, and the new site crashes whenever it goes to anything that I've changed. In particular, I added a link to a new setup with an extra controller/model/view group. It works fine on development but in production it gives me a 404. Yes, I did copy all the files up. I even put everything back how it was, but the website is still showing the broken version of it. I checked the tmp/cache folder but it was empty. Running dispatch.fcgi shows the old site (which I expected) but it still shows the flawed new site when I connect through a browser. I've been tearing my hair out trying to get this to work. Any ideas as to how I can get this to work?

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  • How to avoid concurrent execution of a time-consuming task without blocking?

    - by Diego V
    I want to efficiently avoid concurrent execution of a time-consuming task in a heavily multi-threaded environment without making threads wait for a lock when another thread is already running the task. Instead, in that scenario, I want them to gracefully fail (i.e. skip its attempt to execute the task) as fast as possible. To illustrate the idea considerer this unsafe (has race condition!) code: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing running = true; try { runExpensiveTask(); } finally { running = false; } } I though about using a variation of Double-Checked Locking (consider that running is a primitive 32-bit field, hence atomic, it could work fine even for Java below 5 without the need of volatile). It could look like this: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing synchronized (ThisClass.class) { if (running) return; running = true; try { runExpensiveTask(); } finally { running = false; } } } Maybe I should also use a local copy of the field as well (not sure now, please tell me). But then I realized that anyway I will end with an inner synchronization block, that still could hold a thread with the right timing at monitor entrance until the original executor leaves the critical section (I know the odds usually are minimal but in this case we are thinking in several threads competing for this long-running resource). So, could you think in a better approach?

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  • Zimbra Problems

    - by Imax Satria
    I have a problem with my Zimbra Server, yahoo mail can't reply to my Zimbra Server, this the failure notice from yahoo : Sorry, we were unable to deliver your message to the following address. : No MX or A records for imaxsatria.25u.com --- Below this line is a copy of the message. Received: from [106.10.166.123] by nm17.bullet.mail.sg3.yahoo.com with NNFMP; 30 Aug 2012 00:06:07 -0000 Received: from [106.10.151.252] by tm12.bullet.mail.sg3.yahoo.com with NNFMP; 30 Aug 2012 00:06:07 -0000 Received: from [127.0.0.1] by omp1001.mail.sg3.yahoo.com with NNFMP; 30 Aug 2012 00:06:07 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: [email protected] Received: (qmail 46619 invoked by uid 60001); 30 Aug 2012 00:06:07 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1346285167; bh=JOd9hQyuDhBSxyuVvYQwIVOo6Dp7C1wsnvprDYxGUn8=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; ................... Can you help me?

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  • How to use a TFileStream to read 2D matrices into dynamic array?

    - by Robert Frank
    I need to read a large (2000x2000) matrix of binary data from a file into a dynamic array with Delphi 2010. I don't know the dimensions until run-time. I've never read raw data like this, and don't know IEEE so I'm posting this to see if I'm on track. I plan to use a TFileStream to read one row at a time. I need to be able to read as many of these formats as possible: 16-bit two's complement binary integer 32-bit two's complement binary integer 64-bit two's complement binary integer IEEE single precision floating-point For 32-bit two's complement, I'm thinking something like the code below. Changing to Int64 and Int16 should be straight forward. How can I read the IEEE? Am I on the right track? Any suggestions on this code, or how to elegantly extend it for all 4 data types above? Since my post-processing will be the same after reading this data, I guess I'll have to copy the matrix into a common format when done. I have no problem just having four procedures (one for each data type) like the one below, but perhaps there's an elegant way to use RTTI or buffers and then move()'s so that the same code works for all 4 datatypes? Thanks! type TRowData = array of Int32; procedure ReadMatrix; var Matrix: array of TRowData; NumberOfRows: Cardinal; NumberOfCols: Cardinal; CurRow: Integer; begin NumberOfRows := 20; // not known until run time NumberOfCols := 100; // not known until run time SetLength(Matrix, NumberOfRows); for CurRow := 0 to NumberOfRows do begin SetLength(Matrix[CurRow], NumberOfCols); FileStream.ReadBuffer(Matrix[CurRow], NumberOfCols * SizeOf(Int32)) ); end; end;

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  • Advice: Python Framework Server/Worker Queue management (not Website)

    - by Muppet Geoff
    I am looking for some advice/opinions of which Python Framework to use in an implementation of multiple 'Worker' PCs co-ordinated from a central Queue Manager. For completeness, the 'Worker' PCs will be running Audio Conversion routines (which I do not need advice on, and have standalone code that works). The Audio conversion takes a long time, and I need to co-ordinate an arbitrary number of the 'Workers' from a central location, handing them conversion tasks (such as where to get the source files, or where to ask for the job configuration) with them reporting back some additional info, such as the runtime of the converted audio etc. At present, I have a script that makes a webservice call to get the 'configuration' for a conversion task, based on source files located on the worker already (we manually copy the source files to the worker, and that triggers a conversion routine). I want to change this, so that we can distribute conversion tasks ("Oy you, process this: xxx") based on availability, and in an ideal world, based on pending tasks too. There is a chance that Workers can go offline mid-conversion (but this is not likely). All the workers are Windows based, the co-ordinator can be WIndows or Linux. I have (in my initial searches) come across the following - and I know that some are cross-dependent: Celery (with RabbitMQ) Twisted Django Using a framework, rather than home-brewing, seems to make more sense to me right now. I have a limited timeframe in which to develop this functional extension. An additional consideration would be using a Framework that is compatible with PyQT/PySide so that I can write a simple UI to display Queue status etc. I appreciate that the specifics above are a little vague, and I hope that someone can offer me a pointer or two. Again: I am looking for general advice on which Python framework to investigate further, for developing a Server/Worker 'Queue management' solution, for non-web activities (this is why DJango didn't seem the right fit).

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  • Stored Procedure: Reducing Table Data

    - by SumGuy
    Hi Guys, A simple question about Stored Procedures. I have one stored procedure collecting a whole bunch of data in a table. I then call this procedure from within another stored procedure. I can copy the data into a new table created in the calling procedure but as far as I can see the tables have to be identical. Is this right? Or is there a way to insert only the data I want? For example.... I have one procedure which returns this: SELECT @batch as Batch, @Count as Qty, pd.Location, cast(pd.GL as decimal(10,3)) as [Length], cast(pd.GW as decimal(10,3)) as Width, cast(pd.GT as decimal(10,3)) as Thickness FROM propertydata pd GROUP BY pd.Location, pd.GL, pd.GW, pd.GT I then call this procedure but only want the following data: DECLARE @BatchTable TABLE ( Batch varchar(50), [Length] decimal(10,3), Width decimal(10,3), Thickness decimal(10,3), ) INSERT @BatchTable (Batch, [Length], Width, Thickness) EXEC dbo.batch_drawings_NEW @batch So in the second command I don't want the Qty and Location values. However the code above keeps returning the error: "Insert Error: Column name or number of supplied values does not match table"

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