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• Unserializing an API return object (PHP/Ebay API)

  - by DavidYell

  I have been working with the Ebay api for a project and have found it great. I have however found a problem now, more PHP related. When I read my items from Ebay, I store a bunch of details in the database. Currently, just for the sake of it really, I serialize the whole return object and store it in the database in a related table. The idea being, that when I display my information, I have all the details to hand should I need them. The problem arises in that the pricing information is always in a sub object. [ConvertedAdjustmentAmount] => __PHP_Incomplete_Class Object ( [__PHP_Incomplete_Class_Name] => eBayAmountType [_] => 0 [currencyID] => USD ) As you can see when I unserialize my object, my cunning plan falls foul of the Incomplete class problem. I have checked the following question, without success. http://stackoverflow.com/questions/965611/forcing-access-to-php-incomplete-class-object-properties The main issue lies, as far as I can see, in that the price class is stored in the Ebay api, so how do I recreate it? I have been reading this page, http://uk3.php.net/manual/en/function.unserialize.php and trying to figure out, unserialize_callback_func which I can't figure out either, so any help would be appreciated!

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• Optimization of SQL query regarding pair comparisons

  - by InfiniteSquirrel

  Hi, I'm working on a pair comparison site where a user loads a list of films and grades from another site. My site then picks two random movies and matches them against each other, the user selects the better of the two and a new pair is loaded. This gives a complete list of movies ordered by whichever is best. The database contains three tables; fm_film_data - this contains all imported movies fm_film_data(id int(11), imdb_id varchar(10), tmdb_id varchar(10), title varchar(255), original_title varchar(255), year year(4), director text, description text, poster_url varchar(255)) fm_films - this contains all information related to a user, what movies the user has seen, what grades the user has given, as well as information about each film's wins/losses for that user. fm_films(id int(11), user_id int(11), film_id int(11), grade int(11), wins int(11), losses int(11)) fm_log - this contains records of every duel that has occurred. fm_log(id int(11), user_id int(11), winner int(11), loser int(11)) To pick a pair to show the user, I've created a mySQL query that checks the log and picks a pair at random. SELECT pair.id1, pair.id2 FROM (SELECT part1.id AS id1, part2.id AS id2 FROM fm_films AS part1, fm_films AS part2 WHERE part1.id <> part2.id AND part1.user_id = [!!USERID!!] AND part2.user_id = [!!USERID!!]) AS pair LEFT JOIN (SELECT winner AS id1, loser AS id2 FROM fm_log WHERE fm_log.user_id = [!!USERID!!] UNION SELECT loser AS id1, winner AS id2 FROM fm_log WHERE fm_log.user_id = [!!USERID!!]) AS log ON pair.id1 = log.id1 AND pair.id2 = log.id2 WHERE log.id1 IS NULL ORDER BY RAND() LIMIT 1 This query takes some time to load, about 6 seconds in our tests with two users with about 800 grades each. I'm looking for a way to optimize this but still limit all duels to appear only once. The server runs MySQL version 5.0.90-community.

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• architecture - centraled location for different modules (cms, webapplications, ...) - best practise

  - by NicoJuicy

  Let's just say that i want to create a cms + other online applications. I want them all to integrate into a central location, but they also have to be available seperately (not everyone want's more than the cms solution). Would i create a huge central application that contains all the database, which communicates through a webserice with the "standalone - integrated" modules? Or would i create them seperately and the only thing that the "central" application would do is syncing the information (eg. the cms and another solution can have the same tables (eg. clients or employees). Or do you have another idea? (i know i'm a little vague, but i can't "give" a lot of details because of work - contract). If someone has all the "packages" it should be possible for the central application to integrate all the modules at one place! Or if someone has more than 1 module, it should combine this on the website. What i thought is best, is that the central location contains only the users and their rights (eg. cms - all rights, ...), and the information get synced with every change. (module cms, adding a new client - store locally and send data to the central location, central location - send to modules = table clients updated everywhere) This way it is easy if someone only "bought" a module, they can sync it easily through the complete architecture. I hope i made myself clear!

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• XML Doc to JSP to TIFF

  - by SPD

  We have around 100 word templates, every time user gets a business request he goes into shared folder select the template he/she wants and enter information and save it as tiff, these tiffs later processed by some batch program. I am trying to automate this process. So I defined an XML which has Template information like <Template id="1"> <Section id="1"> <fieldName id="1">Date</fieldName> <fieldValue></fieldValue> <fieldtype></fieldType> <fieldProperty>textField</fieldProperty> </Section> <Section id="2"> <fieldName id="2">Claim#</fieldName> <fieldValue></fieldValue> <fieldtype></fieldType> <fieldProperty>textField</fieldProperty> </Section> </Template> Based on the template values I generate the JSP on fly. Now I would like to generate a TIFF file out of it in specified format. I am not sure how to handle this requirement. *edited the original question.

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• Indexing/Performance strategies for vast amount of the same value

  - by DrColossos

  Base information: This is in context to the indexing process of OpenStreetMap data. To simplify the question: the core information is divided into 3 main types with value "W", "R", "N" (VARCHAR(1)). The table has somewhere around ~75M rows, all columns with "W" make up ~42M rows. Existing indexes are not relevant to this question. Now the question itself: The indexing of the data is done via an procedure. Inside this procedure, there are some loops that do the following: [...] SELECT * FROM table WHERE the_key = "W"; [...] The results get looped again and the above query itself is also in a loop. This takes a lot of time and slows down the process massivly. An indexon the_key is obviously useless since all the values that the index might use are the same ("W"). The script itself is running with a speed that is OK, only the SELECTing takes very long. Do I need to create a "special" kind of index that takes this into account and makes the SELECT quicker? If so, which one? need to tune some of the server parameters (they are already tuned and the result that they deliver seem to be good. If needed, I can post them)? have to live with the speed and simply get more hardware to gain more power (Tim Taylor grunt grunt)? Any alternatives to the above points (except rewriting it or not using it)?

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• Creating a network adapter - how hard is it?

  - by Vilx-

  I'm interested in building a little (commercial) device on top of Arduino. I want it to be able to interface with network. Network as in standard Ethernet, Cat5, RJ-45, etc. I know that there is an Ethernet Shield, but it costs even more than the Arduino itself, and it's pretty big. Naturally, I want my device to be as small and as cheap as possible. So I'm thinking about recreating an Ethernet module myself. The problem is - I haven't got any experience with Ethernet, nor do I have a good idea where to start looking. Thus I can't even say if my ideas are feasible. Ultimately I would like the device to have three ports - one for incoming signal, two for outgoing, so the device is essentially a little switch where it is plugged in itself as well. The switching capabilities need not be very fast - the volume of data will be low. 10Mbit is more than enough, can be even slower. If that is not possible, a single port for controlling the device itself will also do. Another possibility I'm considering is power line communications - sending information through power lines. That's another area I've no experience with. What hardware should I be looking at, and where can I find information about the necessary software? So - can anyone tell me if these ideas are feasible, and if yes - where should I start looking?

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• Should developers *really* have private offices?

  - by Aron Rotteveel

  We will probably be moving within a year, so we have to make some decisions regarding office layout. At the moment, our company is basically one big office. When our developers can't bother to be disturbed at all, we all have our own headphones to mute the outside world. Still, it seems a lot of people feel that private offices are no doubt the way to go. From Joel's article Private Offices Redux: Not every programmer in the world wants to work in a private office. In fact quite a few would tell you unequivocally that they prefer the camaradarie and easy information sharing of an open space. Don't fall for it. They also want M&Ms for breakfast and a pony. Open space is fun but not productive. Even though I can understand the benefit on productivity, does having a private office really result in more net productivity? There seem to be plenty of companies that create wide open spaces and still maintain good productivity. Or so it seems. (I should mention many of them use cubicles, though) What is your opinion on this? What does your company do? Is there some middle ground in this? Some more related information on this matter: Private Offices Redux The new Fog Creek office A Field Guide to Developers Gmail recruitment page. Found this last one somewhat remarkable since the Gmail recruitment page promotes the "wide open space" idea.

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• Bitmap issue in Samsung Galaxy S3

  - by user1531240

  I wrote a method to change Bitmap from camera shot : public Bitmap bitmapChange(Bitmap bm) { /* get original image size */ int w = bm.getWidth(); int h = bm.getHeight(); /* check the image's orientation */ float scale = w / h; if(scale < 1) { /* if the orientation is portrait then scaled and show on the screen*/ float scaleWidth = (float) 90 / (float) w; float scaleHeight = (float) 130 / (float) h; Matrix mtx = new Matrix(); mtx.postScale(scaleWidth, scaleHeight); Bitmap rotatedBMP = Bitmap.createBitmap(bm, 0, 0, w, h, mtx, true); return rotatedBMP; } else { /* if the orientation is landscape then rotate 90 */ float scaleWidth = (float) 130 / (float) w; float scaleHeight = (float) 90 / (float) h; Matrix mtx = new Matrix(); mtx.postScale(scaleWidth, scaleHeight); mtx.postRotate(90); Bitmap rotatedBMP = Bitmap.createBitmap(bm, 0, 0, w, h, mtx, true); return rotatedBMP; } } It works fine in another Android device, even Galaxy Nexus but in Samsung Galaxy S3, the scaled image doesn't show on screen. I tried to mark the bitmapChange method , let it show the original size Bitmap on screen but S3 also show nothing on screen. The information of variables in eclipse is here. The information of sony xperia is here. xperia and other device is working fine.

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• Reducing Dimension For SVM in Sensor Network

  - by iinception

  Hi Everyone, I am looking for some suggestions on a problem that I am currently facing. I have a set of sensor say S1-S100 which is triggered when some event E1-E20 is performed. Assume, normally E1 triggers S1-S20, E2 triggers S15-S30, E3 triggers S20-s50 etc and E1-E20 are completely independent events. Occasionally an event E might trigger any other unrelated sensor. I am using ensemble of 20 svm to analyze each event separately. My features are sensor frequency F1-F100, number of times each sensor is triggered and few other related features. I am looking for a technique that can reduce the dimensionality of the sensor feature(F1-F100)/ or some techniques that encompasses all of the sensor and reduces the dimension too(i was looking for some information theory concept for last few days) . I dont think averaging, maximization is a good idea as I risk loosing information(it did not give me good result). Can somebody please suggest what am I missing here? A paper or some starting idea... Thanks in advance.

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• tiemout for a function that waits indefiinitely (like listen())

  - by Fantastic Fourier

  Hello, I'm not quite sure if it's possible to do what I'm about to ask so I thought I'd ask. I have a multi-threaded program where threads share a memory block to communicate necessary information. One of the information is termination of threads where threads constantly check for this value and when the value is changed, they know it's time for pthread_exit(). One of the threads contains listen() function and it seems to wait indefinitely. This can be problematic if there are nobody who wants to make connection and the thread needs to exit but it can't check the value whether thread needs to terminate or not since it's stuck on listen() and can't move beyond. while(1) { listen(); ... if(value == 1) pthread_exit(NULL); } My logic is something like that if it helps illustrate my point better. What I thought would solve the problem is to allow listen() to wait for a duration of time and if nothing happens, it moves on to next statement. Unfortunately, none of two args of listen() involves time limit. I'm not even sure if I'm going about the right way with multi-threaded programming, I'm not much experienced at all. So is this a good approach? Perhaps there is a better way to go about it? Thanks for any insightful comments.

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• Why do we need Audit Columns in Database Tables?

  - by Software Enthusiastic

  Hi I have seen many database designs having following audit columns on all the tables... Created By Create DateTime Updated By Upldated DateTime From one perspective I see tables from the following view... Entity Tables: Good candidate for Audit columns) Reference Tables: Audit columns may or may not required. In some case last update information is not at all required because record is never going to be modified.) Reference Data Tables Like Country Names, Entity State etc... Audit columns may not required because these information is created only during system installation time, and never going to be changed. I have seen many designers blindly put all audit columns to all tables, is this practice good, if yes what could be the reason... I just want to know because to me it seems illogical. It is difficult for me to figure out why do they design their db this way? I am not saying they are wrong or right, just want to know the WHY? You can also suggest me, if there is an alternative auditing patter or solution available... Thanks and Regards

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• Inner or Outer left Join

  - by user1557856

  I'm having difficulty modifying a script for this situation and wondering if someone maybe able to help: I have an address table and a phone table both sharing the same column called id_number. So id_number = 2 on both tables refers to the same entity. Address and phone information used to be stored in one table (the address table) but it is now split into address and phone tables since we moved to Oracle 11g. There is a 3rd table called both_ids. This table also has an id_number column in addition to an other_ids column storing SSN and some other ids. Before the table was split into address and phone tables, I had this script: (Written in Sybase) INSERT INTO sometable_3 ( SELECT a.id_number, a.other_id, NVL(a1.addr_type_code,0) home_addr_type_code, NVL(a1.addr_status_code,0) home_addr_status_code, NVL(a1.addr_pref_ind,0) home_addr_pref_ind, NVL(a1.street1,0) home_street1, NVL(a1.street2,0) home_street2, NVL(a1.street3,0) home_street3, NVL(a1.city,0) home_city, NVL(a1.state_code,0) home_state_code, NVL(a1.zipcode,0) home_zipcode, NVL(a1.zip_suffix,0) home_zip_suffix, NVL(a1.telephone_status_code,0) home_phone_status, NVL(a1.area_code,0) home_area_code, NVL(a1.telephone_number,0) home_phone_number, NVL(a1.extension,0) home_phone_extension, NVL(a1.date_modified,'') home_date_modified FROM both_ids a, address a1 WHERE a.id_number = a1.id_number(+) AND a1.addr_type_code = 'H'); Now that we moved to Oracle 11g, the address and phone information are split. How can I modify the above script to generate the same result in Oracle 11g? Do I have to first do INNER JOIN between address and phone tables and then do a LEFT OUTER JOIN to both_ids? I tried the following and it did not work: Insert Into.. select ... FROM a1. address INNER JOIN t.Phone ON a1.id_number = t.id_number LEFT OUTER JOIN both_ids a ON a.id_number = a1.id_number WHERE a1.adrr_type_code = 'H'

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• Reading lines of data from text files using java

  - by razshan

  I have a text file with x amount of lines. each line holds a integer number. When the user clicks a button, an action is performed via actionlistener where it should list all the values as displayed on the text file. However, right now I have linenum set to 10 implying I already told the code that just work with 10 lines of the text file. So, if my text file has only 3 rows/lines of data...it will list those lines and for rest of the other 7 lines, it will spit out "null". I recall there is a way to use ellipsis to let the program know that you don't know the exact value but at the end it calculates it based on the given information. Where my given information will the number of lines with numbers(data). Below is part of the code. private class thehandler implements ActionListener{ public void actionPerformed(ActionEvent event){ BufferedReader inputFile=null; try { FileReader freader =new FileReader("Data.txt"); inputFile = new BufferedReader(freader); String MAP = ""; int linenum=10; while(linenum > 0) { linenum=linenum-1; MAP = inputFile.readLine();//read the next line until the specfic line is found System.out.println(MAP); } } catch( Exception y ) { y.printStackTrace(); } }}

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• Guidance required: FIrst time gonna work with real high end database (size = 50GB).

  - by claws

  I got a project of designing a Database. This is going to be my first big scale project. Good thing about it is information is mostly organized & currently stored in text files. The size of this information is 50GB. There are going to be few millions of records in each Table. Its going to have around 50 tables. I need to provide a web interface for searching & browsing. I'm going to use MySQL DBMS. I've never worked with a database more than 200MB before. So, speed & performance was never a concern but I followed things like normalization & Indexes. I never used any kind of testing/benchmarking/queryOptimization/whatever because I never had to care about them. But here the purpose of creating a database is to make it quickly searchable. So, I need to consider all possible aspects in design. I was browsing archives & found: http://stackoverflow.com/questions/1981526/what-should-every-developer-know-about-databases http://stackoverflow.com/questions/621884/database-development-mistakes-made-by-app-developers I'm gonna keep the points mentioned in above answers in mind. What else should I know? What else should I keep in mind?

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• How to configure an index.htm file in IIS?

  - by salvationishere

  I am running IIS 6.0 on an XP OS using VS 2008 and SQL Server 2008 (Full install). I developed two web apps. Both of these I can run from IIS by setting them to the default website. However, now I tried adding an index.htm file. Real simple; all it has is two hyperlinks to these web apps. But now only the first web app works. The first web app is pure VS. The second web app modifies an Adventureworks database table. But now when I click the hyperlink for the second web app, it gives me the error below. However this error doesn't make sense to me cause I have the two web apps configured as two virtual directories beneath C:\inetpub\ and the index.htm file is also beneath C:\inetpub. And the default website is set to home directory C:\inetpub\ with Document index.htm on top. Also, why does the first web app work and not the second now? Server Error in '/AddFileToSQL' Application. The path '/AddFileToSQL/App_GlobalResources/' maps to a directory outside this application, which is not supported. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Web.HttpException: The path '/AddFileToSQL/App_GlobalResources/' maps to a directory outside this application, which is not supported. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

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• Are there any less costly alternatives to Amazon's Relational Database Services (RDS)?

  - by swapnonil

  Hi All, I have the following requirement. I have with me a database containing the contact and address details of at least 2000 members of my school alumni organization. We want to store all that information in a relation model so that This data can be created and edited on demand. This data is always backed up and should be simple to restore in case the master copy becomes unusable. All sensitive personal information residing in this database is guaranteed to be available only to authorized users. This database won't be online in the first 6 months. It will become online only after a website is built on top of it. I am not a DBA and I don't want to spend time doing things like backups. I thought Amazon's RDS with it's automatic backup facility was the perfect solution for our needs. The only problem is that being a voluntary organization we cannot spare the monthly $100 to $150 fees this service demands. So my question is, are there any less costlier alternatives to Amazon's RDS?

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• Smart way to execute function in flash from an imported html (or XML) plain text

  - by DomingoSL

  Ok, here is the think. I have a very simple flash program code in AS3, inside this program there is a dynamic textfield html capable. Also i have a database were i will put some information. Each element in the database can be linked to other. For example, this database will contain tourist spots, and they can be related with others in the same database. Ramdom place 1 This interesting spot is near <link to="ramdo2">ramdom place2</link>. And so, so so... The information in the database is retrived by the flash application and it shows the text on the dynamic textfield. I need somehow to tell my flash application that have to be a link to other part of the database, so when the user click the link a function in flash call this new data. The database is a simple Mysql server, and the data is not yet in there, waiting for your suggestions of how to format it and develop the solution. Im a php developer too, so i can make a gateway in PHP to read the MySQL and then retrive some format to flash, an XML for example.

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• How to use multiple identity numbers in one table?

  - by vincer

  I have an web application that creates printable forms, these forms have a unique number on them, the problem is I have 2 forms that separate numbers need to be created for them. ie) Form1- Numbered 2000000-2999999 Form2- Numbered 3000000-3999999 dbo.test2 - is my form information table Tsel - is my autoinc table for the 3000000 series numbers Tadv - is my autoinc table for the 2000000 series numbers What I have done is create 2 tables with just autoinc row (one for 2000000 series numbers and one for 3000000 series numbers), I then created a trigger to add a record to the coresponding table, read back the autoinc number and add it to my table that stores the form information including the just created autoinc number for the right series of forms. Although it does work, I'm concerned that the numbers will get messed up under load. I'm not sure the @@IDENTITY will always return the right value when many people are using the system. (I cannot have duplicates and I need to use the numbering form show above. See code below. ** TRIGGER ** CREATE TRIGGER MAKEANID2 ON dbo.test2 AFTER INSERT AS SET NOCOUNT ON declare @someid int declare @someid2 int declare @startfrom int declare @test1 varchar(10) select @someid=@@IDENTITY select @test1 = (Select name1 from test2 where sysid = @someid ) if @test1 = 'select' begin insert into Tsel Default values select @someid2 = @@IDENTITY end if @test1 = 'adv' begin insert into Tadv Default values select @someid2 = @@IDENTITY end update test2 set name2=(@someid2) where sysid = @someid SET NOCOUNT OFF

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• Cross-Origin Resource Sharing (CORS) - am I missing something here?

  - by David Semeria

  I was reading about CORS (https://developer.mozilla.org/en/HTTP_access_control) and I think the implementation is both simple and effective. However, unless I'm missing something, I think there's a big part missing from the spec. As I understand, it's the foreign site that decides, based on the origin of the request (and optionally including credentials), whether to allow access to its resources. This is fine. But what if malicious code on the page wants to POST a user's sensitive information to a foreign site? The foreign site is obviously going to authenticate the request. Hence, again if I'm not missing something, CORS actually makes it easier to steal sensitive information. I think it would have made much more sense if the original site could also supply an immutable list of servers its page is allowed to access. So the expanded sequence would be: 1) Supply a page with list of acceptable CORS servers (abc.com, xyz.com, etc) 2) Page wants to make an XHR request to abc.com - the browser allows this because it's in the allowed list and authentication proceeds as normal 3) Page wants to make an XHR request to malicious.com - request rejected locally (ie by the browser) because the server is not in the list. I know that malicious code could still use JSONP to do its dirty work, but I would have thought that a complete implementation of CORS would imply the closing of the script tag multi-site loophole. I also checked out the official CORS spec (http://www.w3.org/TR/cors) and could not find any mention of this issue.

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• Check a list of packages to install with apt-get

  - by Joel

  I am writing a post-install script for Ubuntu in Perl (same script as seen here). One of the steps is to install a list of packages. The problem is that if apt-get install fails in some of many different ways for any one of the packages the script dies badly. I would like to prevent that from happening. This happens because of the ways that apt-get install fails for packages that it doesn't like. For example when I try to install a nonsense word (i.e. typed in the wrong package name) $ sudo apt-get install oblihbyvl Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package oblihbyvl but if instead the package name has been obsoleted (installing handbrake from ppa) $ sudo apt-get install handbrake Reading package lists... Done Building dependency tree Reading state information... Done Package handbrake is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'handbrake' has no installation candidate $ apt-cache search handbrake handbrake-cli - versatile DVD ripper and video transcoder - command line handbrake-gtk - versatile DVD ripper and video transcoder - GTK GUI I have tried parsing the results of apt-cache and apt-get -s install to try to catch all possibilities before doing the install, but I seem to keep finding new ways to allow failures to continue to the actual install system command. My question is, is there some facility either in Perl (e.g. a module, though I would like to avoid installing modules if possible as this is supposed to be the first thing run after a new install of Ubuntu) or apt-* or dpkg that would let me be sure that the packages are all available to be installed before installing and if not fail gracefully in some way that lets the user decide what to do?

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• why create CLSID_CaptureGraphBuilder2 instance always failed in a machine

  - by Yigang Wu

  It's a real strange issue, the machine information below is from DXDiag. There is no error reported, but create CLSID_CaptureGraphBuilder2 instance always failed in the machine. It's okay to create CLSID_FilterGraph. Before create CLSID_CaptureGraphBuilder2, I have called CoInitialize and created CLSID_FilterGraph. Only this machine has the error, what dll related with this interface or any function needed to call before to make it work? Thanks in advance. System Information Time of this report: 4/24/2010, 09:46:58 Machine name: TURION Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_qfe.100216-1510) Language: Japanese (Regional Setting: Japanese) System Manufacturer: To Be Filled By O.E.M. System Model: MS-7145 BIOS: Default System BIOS Processor: AMD Turion(tm) 64 Mobile Technology MT-30, MMX, 3DNow, ~1.6GHz Memory: 768MB RAM Page File: 376MB used, 1401MB available Windows Dir: C:\WINDOWS DirectX Version: DirectX 9.0c (4.09.0000.0904) DX Setup Parameters: Not found DxDiag Version: 5.03.2600.5512 32bit Unicode DxDiag Notes DirectX Files Tab: No problems found. Display Tab 1: No problems found. Sound Tab 1: No problems found. Sound Tab 2: No problems found. Music Tab: No problems found. Input Tab: No problems found. Network Tab: No problems found.

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• UDP security and identifying incoming data.

  - by Charles

  I have been creating an application using UDP for transmitting and receiving information. The problem I am running into is security. Right now I am using the IP/socketid in determining what data belongs to whom. However, I have been reading about how people could simply spoof their IP, then just send data as a specific IP. So this seems to be the wrong way to do it (insecure). So how else am I suppose to identify what data belongs to what users? For instance you have 10 users connected, all have specific data. The server would need to match the user data to this data we received. The only way I can see to do this is to use some sort of client/server key system and encrypt the data. I am curious as to how other applications (or games, since that's what this application is) make sure their data is genuine. Also there is the fact that encryption takes much longer to process than unencrypted. Although I am not sure by how much it will affect performance. Any information would be appreciated. Thanks.

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• Managing My Database in Source Control

  - by Jason

  As I am working with a new database project (within VS2008), and as I have never developed a database from scratch, I immediately began looking into how to manage a database within source control (in this case, Subversion). I found some information on SO, including this post: Keeping development databases in multiple environments in sync. One of the answers in particular pointed to a number of a links, all of which had good, useful information. I was reading a series of posts by K. Scott Allen which describe how he manages database change. From my reading (and please pardon the noobishness of my question), it seems as though the database itself is never checked into a repository. Rather, scripts that can build the database, along with test data (which is also populated from scripts) is checked into the repository. Ultimately, this means that, when a developer is testing his or her app, these scripts, which are part of the build process, are run. This ensures that the database is up-to-date, but is also run locally from every developer's machine. This makes sense to me (if I am indeed reading that correctly). However, if I am missing something, I would appreciate correction or additional guidance. In addition, another question I wanted to ask - does this also mean that I should NOT check in the mdf or ldf files that are created from Visual Studio? Thanks for any help and additional insight. Always appreciated.

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• Managing StringBuilder Resources

  - by Jim Fell

  My C# (.NET 2.0) application has a StringBuilder variable with a capacity of 2.5MB. Obviously, I do not want to copy such a large buffer to a larger buffer space every time it fills. By that point, there is so much data in the buffer anyways, removing the older data is a viable option. Can anyone see any obvious problems with how I'm doing this (i.e. am I introducing more performance problems than I'm solving), or does it look okay? tText_c = new StringBuilder(2500000, 2500000); private void AppendToText(string text) { if (tText_c.Length * 100 / tText_c.Capacity > 95) { tText_c.Remove(0, tText_c.Length / 2); } tText_c.Append(text); } EDIT: Additional information: In this application new data is received very rapidly (on the order of milliseconds) through a serial connection. I don't want to populate the multiline textbox with this new information so frequently because that kills the performance of the application, so I'm saving it to a StringBuilder. Every so often, the application copies the contents of the StringBuilder to the textbox and wipes out the StringBuilder contents.

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• How to efficiently implement a strategy pattern with spring ?

  - by Anth0

  I have a web application developped in J2EE 1.5 with Spring framework. Application contains "dashboards" which are simple pages where a bunch of information are regrouped and where user can modify some status. Managers want me to add a logging system in database for three of theses dashboards. Each dashboard has different information but the log should be traced by date and user's login. What I'd like to do is to implement the Strategy pattern kind of like this : interface DashboardLog { void createLog(String login, Date now); } // Implementation for one dashboard class PrintDashboardLog implements DashboardLog { Integer docId; String status; void createLog(String login, Date now){ // Some code } } class DashboardsManager { DashboardLog logger; String login; Date now; void createLog(){ logger.log(login,now); } } class UpdateDocAction{ DashboardsManager dbManager; void updateSomeField(){ // Some action // Now it's time to log dbManagers.setLogger = new PrintDashboardLog(docId, status); dbManagers.createLog(); } } Is it "correct" (good practice, performance, ...) to do it this way ? Is there a better way ? Note :I did not write basic stuff like constructors and getter/setter.

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