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  • Need a less frustrating alternative to SVN

    - by hatingSVN
    It seems to me that whenever I try to do something in SVN, something messes up: Something as simple as renaming a directory would often cause an error of some sort when checking in the commit. Reverting changes to files, which was probably exactly what SVN was designed for, is incredibly error prone. Checking in a previous version is bound to blow up with some inconsistency error, and a series of unintuitive steps are required to correctly do it. Problems occur often and are usually extremely frustrating to fix. Fixing SVN problems for me involves countless attempts to commit a version of the code, getting an error, deleting the project, checking in the project, and repeat. It should be easy for multiple people to work on the project and commit changes. It is not. When you try to commit a file after someone else committed the same file, SVN is guaranteed to blow up. I haven't even mentioned branching and merging. No surprises here, merging is very prone to errors and the errors are difficult to correct. /rant What version control software best minimizes my frustrations?

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  • Powershell - Splitting string into seperate components

    - by TheD
    I am writing a script which will basically do the following: Read from a text file some arguements: DriveLetter ThreeLetterCode ServerName VolumeLetter Integer Eg. W MSS SERVER01 C 1 These values happen to form a folder destination W:\MSS\, and a filename which works in the following naming convention: SERVERNAME_VOLUMELETTER_VOL-b00X-iYYY.spi - Where The X is the Integer above The value Y I need to work out later, as this happens to be the value of the incremental image (backups) and I need to work out the latest incremental. So at the moment -- Count lines in file, and loop for this many lines. $lines = Get-Content -Path PostBackupCheck-Textfile.txt | Measure-Object -Line for ($i=0; $i -le $lines.Lines; $i++) Within this loop I need to do a Get-Content to read off the line I am currently looking at i.e. line 0, line 1, line 2, as there will be multiple lines in the format I wrote at the beginning and split the line into an array, whereby each part of the file, as seen above naming convention, is in a[0], a[1], a[2]. etc The reason for this is because, I need to then sort the folder that contains these, find the latest file, by date, and take the _iXXX.spi part and place this into the array value a[X] so I then have a complete filename to mount. This value will replace iYYY.spi It's a little complex because I also have to make sure when I do a Get-ChildItem with -Include before I sort it all by date, I am only including the filename that matches the arguements fed to it from the text file : So, SERVER01_C_VOL-b001-iYYY.spi and not anything else. i.e. not SERVER01_D_VOL-b001-iYYY.spi Then take the iYYY value from the sort on the Get-ChildItem -Include and place that into the appropriate array item. I've literally no idea where to start, so any ideas are appreciated! Hopefully I've explained in enough detail. I have also placed the code on Pastebin: http://pastebin.com/vtFifTW6 Thanks!

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  • Hazelcast Distributed Executor Service KeyOwner

    - by János Veres
    I have problem understanding the concept of Hazelcast Distributed Execution. It is said to be able to perform the execution on the owner instance of a specific key. From Documentation: <T> Future<T> submitToKeyOwner(Callable<T> task, Object key) Submits task to owner of the specified key and returns a Future representing that task. Parameters: task - task key - key Returns: a Future representing pending completion of the task I believe that I'm not alone to have a cluster built with multiple maps which might actually use the same key for different purposes, holding different objects (e.g. something along the following setup): IMap<String, ObjectTypeA> firstMap = HazelcastInstance.getMap("firstMap"); IMap<String, ObjectTypeA_AppendixClass> secondMap = HazelcastInstance.getMap("secondMap"); To me it seems quite confusing what documentation says about the owner of a key. My real frustration is that I don't know WHICH - in which map - key does it refer to? The documentation also gives a "demo" of this approach: import com.hazelcast.core.Member; import com.hazelcast.core.Hazelcast; import com.hazelcast.core.IExecutorService; import java.util.concurrent.Callable; import java.util.concurrent.Future; import java.util.Set; import com.hazelcast.config.Config; public void echoOnTheMemberOwningTheKey(String input, Object key) throws Exception { Callable<String> task = new Echo(input); HazelcastInstance hz = Hazelcast.newHazelcastInstance(); IExecutorService executorService = hz.getExecutorService("default"); Future<String> future = executorService.submitToKeyOwner(task, key); String echoResult = future.get(); } Here's a link to the documentation site: Hazelcast MultiHTML Documentation 3.0 - Distributed Execution Did any of you guys figure out in the past what key does it want?

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  • Building a custom (dynamic) dataset and grid

    - by marko.ivanovski.nz
    Hi, I'm in the process of building a dynamic table in which you can add/remove rows & columns so it varies in size depending on what the user wants. Its purpose is to store properties for a product, but there can be from 1 to 10 different properties(columns) per product, and multiple instances(rows) of the product as well. Here's a screenshot of what I mean http://i40.tinypic.com/nbqkxc.jpg As you can see I need the structure to be completely up to the client which is where I'm getting stuck. I've started writing a custom DataSet that has "add column" & "add row" buttons, and have built a custom Table with Textboxes in each cell which builds from that dataset. I have no idea how to store the data on submit though, and to make it even more complex I need to store this in the database as a string which I think I can do by converting it to XML. Any help is appreciated, I think I just need a pointer in the right direction and am happy to do research from there. Thanks in advance. Marko

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  • TRICKEY ONE PLEASE SOLVE

    - by jack
    Create a DTD to record the sellers of merchandise to the Second-hand shop. Each seller has the child elements sellerID (in the format KSXXXXXXX), name, address, phone and sighted_identification. ? the name element has child elements of title and firstname and surname ? the address element has child elements address_line, suburb, state and postcode ? the sighted_identification can be any of the following – passport – drivers licence – birth certificate – Medicare card. –1. Create a DTD to record the sellers of merchandise to the Second-hand shop. Each seller has the child elements sellerID (in the format KSXXXXXXX), name, address, phone and sighted_identification. ? the name element has child elements of title and firstname and surname ? the address element has child elements address_line, suburb, state and postcode ? the sighted_identification can be any of the following – passport – drivers licence – birth certificate – Medicare card. Create an XML document for five sellers including at least two with multiple sighted identifications. 3. Create an XSLT style sheet to logically display all of the seller’s details. Note 1: it may help you to create lists for both sellers and for sighted_identification. Note 2: The shops database stores the sighted identification of sellers as p, dl, bc and mc rather than by their full name, so creating an entity for each type is required. Note 3: Your XSLT should order the sellers by sellerID – for this reason don’t have them ordered correctly in the XML file – rather sort the sellerID within the XSLT. OUTPUT SHOULD BE SOMETHING LIKE THIS SELLER ID : NAME: ADDRESS : PHONE : IDENTIFICATION : IDENTIFICATION : IDENTIFICATION :

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  • Application error passthru when using apache mod_proxy

    - by user303442
    Heyas. I'm using mod_proxy with apache2 provide vhost ability to multiple servlet apps running on the local machine. It works fine, for the most part. Requests come into apache then are directed to the application bound on a port on localhost. The app receives the request and responds, which is delivered back to the client by apache. The problem I'm having is that the application delivers 500's on errors, and mod_proxy stomps on them. Often these errors are caused in a ajax request and the error is handled in client side javascript. For example, a call to a server side createObject(name) might throw a NameNotUniqueException , which is delivered back as a 500. The client javascript might then display an appropriate error message. When an error is thrown by the application (resulting in a 500 response to mod_proxy), then apache stomps the error message and returns 500 Internal Server Error Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. .. the stock apache server side error message. I want mod_proxy to pass the original 500 back through to the client. Is there a directive I've missed which prevents clobbering of the 500? TIA

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  • Customize jQuery.aptags plugin - mouseclick submit from dropdown list

    - by atmorell
    Hello, I am using jquery.autocomplete.js and jquery.apitags to select a few elements from a dropdown list. This works great, and I can select multiple elements etc. However the jquery-aptags plugin does only fire when enter is pressed. This might confuse some users if they use the mouse to click instead of the arrows/enter on the keyboard. I think this is the code inside jquery.aptags that submits the tag. // // Hook to the keypress event. // $(this).bind('keypress', { __c: __c }, function (e) { var c = ''; var i = 0; var v = $(this).val(); if (e.keyCode == 13) { e.stopPropagation(); e.preventDefault(); __createSpans(this, v, e.data.__c, true); } }); I am wondering if it is possible to call the method directly from a new event. $('.ac_results > ul > li').livequery(function() { $(this).bind('click', function() { $('#address_city').aptags({__createSpans}); }); }); Any thoughts?

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  • How to install DBD::mysql on OS X server?

    - by Zoran Simic
    Trying to install DBD::mysql on OS X Server 10.6 (mac mini server). But I'm missing the mysql headers apparently. Since mysql is already part of OS X Server 10.6, I would like to NOT install anything else (no fink or darwin ports installs), just whatever's needed to get DBD::mysql installed and working. Do you know how I could do that? Do I have to install the headers somewhere? And if so, where? (again: I don't want to install another version of mysql on the box, want to use the version it came with). Is there a way to install DBD::mysql without compiling any C files? This is the error I get (the actual error is much longer, but these are the most meaningful bits, this is the first error reported). Checking if your kit is complete... Looks good Unrecognized argument in LIBS ignored: '-pipe' Note (probably harmless): No library found for -lmysqlclient Multiple copies of Driver.xst found in: /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level/auto/DBI/ at Makefile.PL line 907 Using DBI 1.611 (for perl 5.010000 on darwin-thread-multi-2level) installed in /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ Writing Makefile for DBD::mysql cp lib/DBD/mysql.pm blib/lib/DBD/mysql.pm cp lib/DBD/mysql/GetInfo.pm blib/lib/DBD/mysql/GetInfo.pm cp lib/DBD/mysql/INSTALL.pod blib/lib/DBD/mysql/INSTALL.pod cp lib/Bundle/DBD/mysql.pm blib/lib/Bundle/DBD/mysql.pm gcc-4.2 -c -I/Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI -I/usr/include -fno-omit-frame-pointer -pipe -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT -DDBD_MYSQL_INSERT_ID_IS_GOOD -g -arch x86_64 -arch i386 -arch ppc -g -pipe -fno-common -DPERL_DARWIN -fno-strict-aliasing -I/usr/local/include -Os -DVERSION=\"4.014\" -DXS_VERSION=\"4.014\" "-I/System/Library/Perl/5.10.0/darwin-thread-multi-2level/CORE" dbdimp.c In file included from dbdimp.c:20: dbdimp.h:22:49: error: mysql.h: No such file or directory dbdimp.h:23:45: error: mysqld_error.h: No such file or directory dbdimp.h:25:49: error: errmsg.h: No such file or directory

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  • Select box is not working properly after including google custom search box in web page

    - by Vinay
    I have got a select box and google custom search box in a page, when i choose a option from select box and navigate away from the page and again if i come back to the same page the option will not be selected (violates the default functionality of select box), The code is below <script src="https://www.google.com/jsapi" type="text/javascript"></script> <script type="text/javascript"> google.load('search', '1', {language : 'en'}); google.setOnLoadCallback(function() { var customSearchControl = new google.search.CustomSearchControl('004920913350056953771:kpkclvhujzk'); customSearchControl.setResultSetSize(google.search.Search.FILTERED_CSE_RESULTSET); var options = new google.search.DrawOptions(); options.setAutoComplete(true); options.enableSearchboxOnly("<?=$homeurl?>my_results.php", "query"); customSearchControl.draw('cse-search-form', options); }, true); </script> <select multiple="yes"> <option>1</option> <option>2</option> </select> If i remove the custom search script, the select box selected option will be retained even after navigating away from the page. (default functionality) Its working fine in chrome, IE but not in Firefox. Is there any solution for this, so that select box must work fine even in the presence of search box, but the order must be same 1) Search box 2)Select Box

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  • How do I make the left and right gutters different colors with 960.gs?

    - by Andrew Arrow
    How do I make the left and right gutters different colors with 960.gs? When I try something simple like: <div style="background-color: green"> <div class="container_16"> <div class="grid_16"> test </div> </div> </div> <div style="background-color: cyan"> <div class="container_16"> <div class="grid_16"> test </div> </div> </div> The green and cyan colors are ignored. Seems like the "grid_16" class removes the color for some reason? My goal is being able to have different sections of the page in different colors all the way across the page, even past 960 pixels. So if someone makes their browser 1200px the left and right sides have the right color and the rest of the grid system is all contained within the 960 pixels in the middle. I could add a background color to 'body' to do this for just 1 color, but I want multiple colors in the page. Like different colored horizontal stripes. Thanks.

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  • How can I write System preferences with Java? Can I invoke UAC?

    - by Jonas
    How can I write system preferences with Java, using Preferences.systemRoot()? I tried with: Preferences preferences = Preferences.systemRoot(); preferences.put("/myapplication/databasepath", pathToDatabase); But I got this error message: 2010-maj-29 19:02:50 java.util.prefs.WindowsPreferences openKey VARNING: Could not open windows registry node Software\JavaSoft\Prefs at root 0x80000002. Windows RegOpenKey(...) returned error code 5. Exception in thread "AWT-EventQueue-0" java.lang.SecurityException: Could not open windows registry node Software\JavaSoft\Prefs at root 0x80000002: Access denied at java.util.prefs.WindowsPreferences.openKey(Unknown Source) at java.util.prefs.WindowsPreferences.openKey(Unknown Source) at java.util.prefs.WindowsPreferences.openKey(Unknown Source) at java.util.prefs.WindowsPreferences.putSpi(Unknown Source) at java.util.prefs.AbstractPreferences.put(Unknown Source) at biz.accountia.pos.install.Setup$2.actionPerformed(Setup.java:43) I would like to do this, because I want to install an embedded JavaDB database, and let multiple users on the computer to use the same database with the application. How to solve this? Can I invoke UAC and do this as Administrator from Java? And if I log in as Administrator when writing, can I read the values with my Java application if I'm logged in as a User?

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  • How do I bind an iTunes style source list to an NSTableView using Core Data?

    - by Austin
    I have an iTunes style interface in my application: Source list (NSOutlineView) on the left that contains different libraries and playlists with an NSTableView on the right side of the interface displaying information for "Presentations". Similar to iTunes, I am showing the same type of information in the table view whether a library or playlist is selected (title, author, date created, etc). I currently have an NSArrayController connected to my NSTableView and was setting the fetch predicate based on what was selected in the source list. This works fine when selecting a library because I can just set the fetch predicate to filter by the "type" field in my Presentation Core Data entity. When I try to adjust the fetch predicate for the playlist however, it doesn't look like there is any way to set the fetch predicate because I've got a table in between Playlists and Presentations to keep up with the order within the Playlist. According to the Apple docs, these type of predicates are not doable with Core Data (it basically doesn't multiple inner joins). Below is the relevant portion of my Data Model. Is my data model setup incorrectly? Should I drop the NSArrayController and handle connecting the NSTableView up by hand? I'm trying to figure out if there is a simple fix, or really a design flaw.

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  • Considerations when architecting an application using Dependency Injection

    - by Dan Bryant
    I've begun experimenting with dependency injection (in particular, MEF) for one of my projects, which has a number of different extensibility points. I'm starting to get a feel for what I can do with MEF, but I'd like to hear from others who have more experience with the technology. A few specific cases: My main use case at the moment is exposing various singleton-like services that my extensions make use of. My Framework assembly exposes service interfaces and my Engine assembly contains concrete implementations. This works well, but I may not want to allow all of my extensions to have access to all of my services. Is there a good way within MEF to limit which particular imports I allow a newly instantiated extension to resolve? This particular application has extension objects that I repeatedly instantiate. I can import multiple types of Controllers and Machines, which are instantiated in different combinations for a Project. I couldn't find a good way to do this with MEF, so I'm doing my own type discovery and instantiation. Is there a good way to do this within MEF or other DI frameworks? I welcome input on any other things to watch out for or surprising capabilities you've discovered that have changed the way you architect.

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  • How can I programmatically add more than just one view object to my view controller?

    - by BeachRunnerJoe
    I'm diving into iPhone OS development and I'm trying to understand how I can add multiple view objects to the "Left/Root" view of my SplitView iPad app. I've figured out how to programmatically add a TableView to that view based on the example code I found in Apple's online documentation... RootViewController.h @interface RootViewController : UITableViewController <NSFetchedResultsControllerDelegate, UITableViewDelegate, UITableViewDataSource> { DetailViewController *detailViewController; UITableView *tableView; NSFetchedResultsController *fetchedResultsController; NSManagedObjectContext *managedObjectContext; } RootViewController.m - (void)loadView { UITableView *newTableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame] style:UITableViewStylePlain]; newTableView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth; newTableView.delegate = self; newTableView.dataSource = self; [newTableView reloadData]; self.view = newTableView; [newTableView release]; } but there are a few things I don't understand about it and I was hoping you veterans could help clear up some confusion. In the statement self.view = newTableView, I assume I'm setting the entire view to a single UITableView. If that's the case, then how can I add additional view objects to that view alongside the table view? For example, if I wanted to have a DatePicker view object and the TableView object instead of just the TableView object, then how would I programmatically add that? Referencing the code above, how can I resize the table view to make room for the DatePicker view object that I'd like to add? Thanks so much in advance for your help! I'm going to continue researching these questions right now.

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  • Adding Unlimited Form Fields With JQuery Problem.

    - by TheCREATOR
    I'm fairly new to JQuery and I'm trying to add multiple form fields for example, <li id="container" id="add_field"><input type="text" name="text" value="text" /></li> but I think my JQuery code is off can some one please help me fix the JQuery code? Here is the JQuery script. var count = 0; $(function(){ $('li#add_field').click(function(){ count += 1; $('#container').append( '<li><input id="field_' + count + '" name="fields[]' + '" type="text" /></li>' ); }); }); Here is the html code. <form method="post" action="index.php"> <fieldset> <ul> <li><label for="code">Code: </label> <textarea rows="8" cols="60" name="code" id="code"></textarea></li> <li id="container" id="add_field"><input type="text" name="text" value="text" /></li> <li><label for="comment">Comments: </label> <textarea rows="8" cols="60" name="comment" id="comment"></textarea></li> <li><input type="submit" name="submit" value="Submit" /></li></ul> </fieldset> </form>

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  • Visual Studio: How to attach a debugger dynamically to a specific process

    - by Jeff Cyr
    I am building an internal dev tool to manage different processes commonly used in our development environment. The tool show the list the monitored processes, indicate their running state and allow to start or stop each process. I'd like to add the functionality of attaching a debugger to a monitored process from my tool instead of going in 'Debug-Attach to process' in visual studio and finding the process. My goal is to have something like Debugger.Launch() that would show a list of the available visual studio. I can't use Debugger.Launch() because it lauches the debugger on the process that make the call. I would need something like Debugger.Launch(processId). Does anyone know how to acheive this functionality? A solution could be to implement a command in each monitored process to call Debugger.Launch() when the command is received from the monitoring tool, but I would prefer something that does not require to modify the code of the monitored processes. Side question: When using Debugger.Launch(), instances of Visual Studio that already have a debugger attached are not listed. Visual Studio is not limited to one attached debugger, you can attach on multiple process when using 'Debug - Attach to process'. Anyone know how to bypass this limitation when using Debugger.Launch() or an alternative?

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  • loops and conditionals inside triggers

    - by Ying
    I have this piece of logic I would like to implement as a trigger, but I have no idea how to do it! I want to create a trigger that, when a row is deleted, it checks to see if the value of one of its columns exists in another table, and if it does, it should also perform a delete on another table based on another column. So say we had a table Foo that has columns Bar, Baz. This is what id be doing if i did not use a trigger: function deleteFromFooTable(FooId) { SELECT (Bar,Baz) FROM FooTable WHERE id=FooId if not-empty(SELECT * FROM BazTable WHERE id=BazId) DELETE FROM BarTable WHERE id=BarId DELETE FROM FooTable WHERE id=FooId } I jumped some hoops in that pseudo code, but i hope you all get where im going. It seems what i would need is a way to do conditionals and to loop(in case of multiple row deletes?) in the trigger statement. So far, I haven't been able to find anything. Is this not possible, or is this bad practice? Thanks!

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  • Office 2003 interop problems, interface, method not found.

    - by Snake
    This problem is making me crazy. Actually I have multiple problems. First one: Why on earth are is there a _Worksheet and a Worksheetinterface in the Excel interop. They both look the same, except for some attributes on the methods. It's confusing! Second of all: my job today is making a VB.NET file more strict, by settings Option Strict On and Option Explicit On While it works for most files, I'm bumping into a problem. Here's a little code piece: Private _pivotTable As Excel.PivotTable With _pivotTable pvf = .AddDataField(pvc) End With PivotTable.AddDataField is defined on the MSDN page: http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.pivottable.adddatafield(office.11).aspx When I check my local Interop dll w/ Reflector that method is NOT there. When I run the application, and step through it, the method just works. When I try to step INTO the method, I get an LateBound Exception. WTF? So the question is: why are the interfaces defined more than once (twice sometimes?). 2nd question. AddDataField trouble

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  • write html content from javascript

    - by Nikita Rybak
    There's one thing I want to do with javascript, but don't know how. In a perfect world it would look like this: <p>My very cool page!</p> <script type="text/javascript"> document.write('<div>some content</div>'); </script> And this script would insert <div>some content</div> right before (or after, or instead of) script tag. But in the real world, document.write starts writing html anew, removing any static content in the page (<p> tag, in this case). This is simplified example, but should give you the idea. I know that I can statically put <div id="some_id"></div> before script tag and insert html in it from js, but I wanna be able to use multiple instances of this snippet without changing it (generating random id manually) each time. I'm ok to use jquery or any other existing library as well. Is there any way to achieve this? Thanks!

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  • Debian packaging of a Python package.

    - by chrisdew
    I need to write (or find) a script to create a Debian package (using python-support) from a Python package. The Python package will be pure Python (no C extensions). The Python package (for testing purposes) will just be a directory with an empty __init__.py file and a single Python module, package_test.py. The packaging script must use python-support to provide the correct bytecode for possible multiple installations of Python on a target platform. (i.e. v2.5 and v2.6 on Ubuntu Jaunty.) Most advice I find while googling are just examples nasty hacks that don't even use python-support or python-central. I have so far spent hours researching this, and the best I can come up with is to hack around the script from an existing open source project - but I don't know which bits are required for what I'm doing. Has anyone here made a Debian package out of a Python package in a reasonably non-hacky way? I'm starting to think that it will take me more than a week to go from no knowledge of Debian packaging and python-support to getting a working script. How long has it taken others? Any advice? Chris.

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  • Two objects with dependencies for each other. Is that bad?

    - by Kasper Grubbe
    Hi SO. I am learning a lot about design patterns these days. And I want to ask you about a design question that I can't find an answer to. Currently I am building a little Chat-server using sockets, with multiple Clients. Currently I have three classes. Person-class which holds information like nick, age and a Room-object. Room-class which holds information like room-name, topic and a list of Persons currently in that room. Hotel-class which have a list of Persons and a list of Rooms on the server. I have made a diagram to illustrate it (Sorry for the big size!): http://i.imgur.com/Kpq6V.png I have a list of players on the server in the Hotel-class because it would be nice to keep track of how many there are online right now (Without having to iterate through all of the rooms). The persons live in the Hotel-class because I would like to be able to search for a specific Person without searching the rooms. Is this bad design? Is there another way of achieve it? Thanks.

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  • How to distinguish between two different UDP clients on the same IP address?

    - by Ricket
    I'm writing a UDP server, which is a first for me; I've only done a bit of TCP communications. And I'm having trouble figuring out exactly how to distinguish which user is which, since UDP deals only with packets rather than connections and I therefore cannot tell exactly who I'm communicating with. Here is pseudocode of my current server loop: DatagramPacket p; socket.receive(p); // now p contains the user's IP and port, and the data int key = getKey(p); if(key == 0) { // connection request key = makeKey(p); clients.add(key, p.ip); send(p.ip, p.port, key); // give the user his key } else { // user has a key // verify key belongs to that IP address // lookup the user's session data based on the key // react to the packet in the context of the session } When designing this, I kept in mind these points: Multiple users may exist on the same IP address, due to the presence of routers, therefore users must have a separate identification key. Packets can be spoofed, so the key should be checked against its original IP address and ignored if a different IP tries to use the key. The outbound port on the client side might change among packets. Is that third assumption correct, or can I simply assume that one user = one IP+port combination? Is this commonly done, or should I continue to create a special key like I am currently doing? I'm not completely clear on how TCP negotiates a connection so if you think I should model it off of TCP then please link me to a good tutorial or something on TCP's SYN/SYNACK/ACK mess. Also note, I do have a provision to resend a key, if an IP sends a 0 and that IP already has a pending key; I omitted it to keep the snippet simple. I understand that UDP is not guaranteed to arrive, and I plan to add reliability to the main packet handling code later as well.

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  • Need help with WCF design

    - by Jason
    I have been tasked with creating a set of web services. We are a Microsoft shop, so I will be using WCF for this project. There is an interesting design consideration that I haven't been able to figure out a solution for yet. I'll try to explain it with an example: My WCF service exposes a method named Foo(). 10 different users call Foo() at roughly the same time. I have 5 special resources called R1, R2, R3, R4, and R5. We don't really need to know what the resource is, other than the fact that a particular resource can only be in use by one caller at a time. Foo() is responsible to performing an action using one of these special resources. So, in a round-robin fashion, Foo() needs to find a resource that is not in use. If no resources are available, it must wait for one to be freed up. At first, this seems like an easy task. I could maybe create a singleton that keeps track of which resources are currently in use. The big problem is the fact that I need this solution to be viable in a web farm scenario. I'm sure there is a good solution to this problem, but I've just never run across this scenario before. I need some sort of resource tracker / provider that can be shared between multiple WCF hosts. Any ideas from the architects out there would be greatly appreciated!

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  • DataReader-DataSet Hybrid solution

    - by G33kKahuna
    My solution architects and I have exhausted both pure Dataset and Datareader solutions. Basically we have a Microsoft.NET 2.0 windows service application that pulls data based on a query and processes additional tasks per record; almost a poor mans workflow system. The recordsets are broader (in terms of the columns) and deeper (in terms of number of records). We observed that DataSet performs much better in terms of performance but runs into contraints as # of records increase say 100K+ we start seeing System.OutOfMemoryException on a 4G machine with processModel configured to run at memoryLimit set to 85. Since this is a multi-threaded app, there could be multiple threads processing different queries and building different DataSets, so we run into the exception sooner in that case DataReader on the other hand works but is a lot slower and hits other contraints; if there is some sort of disconnect it has to start over again or leaves open connections on the DB side and worst case takes down the service completely etc. So, we decided the best option would be some sort of hybrid solution. I'm open to guidance and suggestions. Are there any hybrid solutions available? Any other suggestions

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  • Computing complex math equations in python

    - by dassouki
    Are there any libraries or techniques that simplify computing equations ? Take the following two examples: F = B * { [ a * b * sumOf (A / B ''' for all i ''' ) ] / [ sumOf(c * d * j) ] } where: F = cost from i to j B, a, b, c, d, j are all vectors in the format [ [zone_i, zone_j, cost_of_i_to_j], [..]] This should produce a vector F [ [1,2, F_1_2], ..., [i,j, F_i_j] ] T_ij = [ P_i * A_i * F_i_j] / [ SumOf [ Aj * F_i_j ] // j = 1 to j = n ] where: n is the number of zones T = vector [ [1, 2, A_1_2, P_1_2], ..., [i, j, A_i_j, P_i_j] ] F = vector [1, 2, F_1_2], ..., [i, j, F_i_j] so P_i would be the sum of all P_i_j for all j and Aj would be sum of all P_j for all i I'm not sure what I'm looking for, but perhaps a parser for these equations or methods to deal with multiple multiplications and products between vectors? To calculate some of the factors, for example A_j, this is what i use from collections import defaultdict A_j_dict = defaultdict(float) for A_item in TG: A_j_dict[A_item[1]] += A_item[3] Although this works fine, I really feel that it is a brute force / hacking method and unmaintainable in the case we want to add more variables or parameters. Are there any math equation parsers you'd recommend? Side Note: These equations are used to model travel. Currently I use excel to solve a lot of these equations; and I find that process to be daunting. I'd rather move to python where it pulls the data directly from our database (postgres) and outputs the results into the database. All that is figured out. I'm just struggling with evaluating the equations themselves. Thanks :)

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