Search Results

Search found 19055 results on 763 pages for 'high performance'.

Page 662/763 | < Previous Page | 658 659 660 661 662 663 664 665 666 667 668 669  | Next Page >

  • django: control json serialization

    - by abolotnov
    Is there a way to control json serialization in django? Simple code below will return serialized object in json: co = Collection.objects.all() c = serializers.serialize('json',co) The json will look similar to this: [ { "pk": 1, "model": "picviewer.collection", "fields": { "urlName": "architecture", "name": "\u0413\u043e\u0440\u043e\u0434 \u0438 \u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u0430", "sortOrder": 0 } }, { "pk": 2, "model": "picviewer.collection", "fields": { "urlName": "nature", "name": "\u041f\u0440\u0438\u0440\u043e\u0434\u0430", "sortOrder": 1 } }, { "pk": 3, "model": "picviewer.collection", "fields": { "urlName": "objects", "name": "\u041e\u0431\u044a\u0435\u043a\u0442\u044b \u0438 \u043d\u0430\u0442\u044e\u0440\u043c\u043e\u0440\u0442", "sortOrder": 2 } } ] You can see it's serializing it in a way that you are able to re-create the whole model, shall you want to do this at some point - fair enough, but not very handy for simple JS ajax in my case: I want bring the traffic to minimum and make the whole thing little clearer. What I did is I created a view that passes the object to a .json template and the template will do something like this to generate "nicer" json output: [ {% if collections %} {% for c in collections %} {"id": {{c.id}},"sortOrder": {{c.sortOrder}},"name": "{{c.name}}","urlName": "{{c.urlName}}"}{% if not forloop.last %},{% endif %} {% endfor %} {% endif %} ] This does work and the output is much (?) nicer: [ { "id": 1, "sortOrder": 0, "name": "????? ? ???????????", "urlName": "architecture" }, { "id": 2, "sortOrder": 1, "name": "???????", "urlName": "nature" }, { "id": 3, "sortOrder": 2, "name": "??????? ? ?????????", "urlName": "objects" } ] However, I'm bothered by the fast that my solution uses templates (an extra step in processing and possible performance impact) and it will take manual work to maintain shall I update the model, for example. I'm thinking json generating should be part of the model (correct me if I'm wrong) and done with either native python-json and django implementation but can't figure how to make it strip the bits that I don't want. One more thing - even when I restrict it to a set of fields to serialize, it will keep the id always outside the element container and instead present it as "pk" outside of it.

    Read the article

  • How does mercurial's bisect work when the range includes branching?

    - by Joshua Goldberg
    If the bisect range includes multiple branches, how does hg bisect's search work. Does it effectively bisect each sub-branch (I would think that would be inefficient)? For instance, borrowing, with gratitude, a diagram from an answer to this related question, what if the bisect got to changeset 7 on the "good" right-side branch first. @ 12:8ae1fff407c8:bad6 | o 11:27edd4ba0a78:bad5 | o 10:312ba3d6eb29:bad4 |\ | o 9:68ae20ea0c02:good33 | | | o 8:916e977fa594:good32 | | | o 7:b9d00094223f:good31 | | o | 6:a7cab1800465:bad3 | | o | 5:a84e45045a29:bad2 | | o | 4:d0a381a67072:bad1 | | o | 3:54349a6276cc:good4 |/ o 2:4588e394e325:good3 | o 1:de79725cb39a:good2 | o 0:2641cc78ce7a:good1 Will it then look only between 7 and 12, missing the real first-bad that we care about? (thus using "dumb" numerical order) or is it smart enough to use the full topography and to know that the first bad could be below 7 on the right-side branch, or could still be anywhere on the left-side branch. The purpose of my question is both (a) just to understand the algorithm better, and (b) to understand whether I can liberally extend my initial bisect range without thinking hard about what branch I go to. I've been in high-branching bisect situations where it kept asking me after every test to extend beyond the next merge, so that the whole procedure was essentially O(n). I'm wondering if I can just throw the first "good" marker way back past some nest of merges without thinking about it much, and whether that would save time and give correct results.

    Read the article

  • Discussion on SEO best-practices for site development involving php...

    - by Bradley Herman
    Recently in our work, I've started getting some experience with SEO (finally). It's something I've put off for a long time because I've always maintained that SEO is a buzz-word b.s. pseudo-science and more about providing quality, relevant content (assuming proper header tags and the basics are covered). However, sometimes a client doesn't have stellar content yet still demands SEO and high rankings. While it's not how I design sites 100% of the time (as design dictates structure), I typically create a basic template from the design my boss gives me, then I optimize it, and then strip the top and bottom and move those to header.php and footer.php, using the following to bring in the header and footer based on AJAX versus HTML requests: <?php if($_SERVER['HTTP_X_REQUESTED_WITH']==''){ include('includes/header.php'); }?> #content here <?php if($_SERVER['HTTP_X_REQUESTED_WITH']==''){ include('includes/footer.php'); }?> Then, I use jQuery to intercept page requests and I use AJAX to fill in, for example, a #copy div with the new content. This avoids unnecessarily loading all the header and footer info everytime, but still allows users without Java to access pages without any problems. (also to think about, depending on size of content, do the extra http requests added using this method render it more of a server strain versus a single, larger file?) I don't have a really solid understanding of the meta keywords and their SEO significance, but as I recall reading, the keywords, title, and description on a page should match up to the pages content--ie. each page should have slightly different keywords/description while retaining some common ground. What I'm getting at here is trying to foster a discussion on whether my approach is flawed to begin with, if there are things I can do (within reason) that keep the site structure simple but allow for better SEO practices, or if my SEO understandings are wrong. This isn't a question, per say, but hopefully a constructive discussion here that more than just I can learn from. I appreciate any responses and hope to hear from you. Thanks!

    Read the article

  • How to receive Email in JEE application

    - by Hank
    Obviously it's not so difficult to send out emails from a JEE application via JavaMail. What I am interested in is the best pattern to receive emails (notification bounces, mostly)? I am not interested in IMAP/POP3-based approaches (polling the inbox) - my application shall react to inbound emails. One approach I could think of would be Keep existing MTA (postfix on linux in my case) - ops team already knows how to configure / operate it For every mail that arrives, spawn a Java app that receives the data and sends it off via JMS. I could do this via an entry in /etc/aliases like myuser: "|/path/to/javahelper" with javahelper calling the Java app, passing STDIN along. MDB (part of JEE application) receives JMS message, parses it, detects bounce message and acts accordingly. Another approach could be Open a listening network socket on port 25 on the JEE application container. Associate a SessionBean with the socket. Bean is part of JEE application and can parse/detect bounces/handle the messages directly. Keep existing MTA as inbound relay, do all its security/spam filtering, but forward emails to myuser (that pass the filter) to the JEE application container, port 25. The first approach I have done before (albeit in a different language/setup). From a performance and (perceived) cleanliness point of view, I think the second approach is better, but it would require me to provide a proper SMTP transport implementation. Also, I don't know if it's at all possible to connect a network socket with a bean... What is your recommendation? Do you have details about the second approach?

    Read the article

  • What arguments to use to explain why SQL Server is far better then a flat file

    - by jamone
    The higher ups in my company were told by good friends that flat files are the way to go, and we should switch from SQL Server to them for everything we do. We have over 300 servers and hundreds of different databases. From just the few I'm involved with we have 10 billion records in quite a few of them with upwards of 100k new records a day and who knows how many updates... Me and a couple others need to come up with a response saying why we shouldn't do this. Most of our stuff is ASP.NET with some legacy ASP. We thought that making a simple console app that tests/times the same interactions between a flat file (stored on the network) and SQL over the network doing large inserts, searches, updates etc along with things like network disconnects randomly. This would show them how bad flat files can be especially when you are dealing with millions of records. What things should I use in my response? What should I do with my demo code to illustrate this? My sort list so far: Security Concurrent access Performance with large amounts of data Amount of time to do such a massive rewrite/switch Lack of transactions PITA to map relational data to flat files NTFS doesn't support tons of files in a directory well I fear that this will be a great post on the Daily WTF someday if I can't stop it now.

    Read the article

  • Trouble Running Leaks Instrument

    - by TheGeoff
    I'm having trouble running the Leaks Instrument since installing the 3.0 SDK. An NDA disclaimer here I don't think this is a 3.0 SDK issue, just a configuration problem. So I'm looking for advice on configuring the tools in question not the 3.0 SDK per se. Here’s the breakdown of the behavior I am seeing. My Application is compiled to OS version 2.2. I can run it out of XCode in debug mode on the Simulator and Device running 2.2, 2.2.1, 3.0. If I start it with Performance Tools - Leaks, I get an error message from the OS, “The application xxxx quit unexpectedly”, “Ignore, Report, Relaunch.” If I click “Ignore” one of two things will happen, either Leaks tells me it couldn’t attach, or Leaks stop responding to input and I have to Force Quit. Interesting thing is the Simulator starts in 3.0 OS. If I start Instruments Manually and attach to a running 2.2 Simulator it shows the same behavior. If I attach Leaks to an iPhone Device it works. It seems that once I launch Leaks my app won't run in the simulator until I do a new build. Any ideas for getting my Simulator/Leaks/Xcode synced back up? Thanks, Geoff

    Read the article

  • Can't send smtp email from network using C#, asp.net website

    - by Kaysar
    Hi, I have my code here, it works fine from my home, where my user is administrator, and I am connected to internet via a cable network. But, problem is when I try this code from my work place, it does not work. Shows error: "unable to connect to the remote server" From a different machine in the same network: "A socket operation was attempted to an unreachable network 209.xxx.xx.52:25" I checked with our network admin, and he assured me that all the mail ports are open [25,110, and other ports for gmail]. Then, I logged in with administrative privilege, there was a little improvement, it did not show any error, but the actual email was never received. Please note that, the code was tested from development environment, visual studio 2005 and 2008. Any suggestion will be much appreciated. Thanks in advance try { MailMessage mail_message = new MailMessage("[email protected]", txtToEmail.Text, txtSubject.Text, txtBody.Text); SmtpClient mail_client = new SmtpClient("SMTP.y7mail.com"); NetworkCredential Authentic = new NetworkCredential("[email protected]", "xxxxx"); mail_client.UseDefaultCredentials = true; mail_client.Credentials = Authentic; mail_message.IsBodyHtml = true; mail_message.Priority = MailPriority.High; try { mail_client.Send(mail_message); lblStatus.Text = "Mail Sent Successfully"; } catch (Exception ex) { System.Diagnostics.Debug.WriteLine(ex.Message); lblStatus.Text = "Mail Sending Failed\r\n" + ex.Message; } } catch (Exception ex) { lblStatus.Text = "Mail Sending Failed\r\n" + ex.Message; }

    Read the article

  • Call method immediately after object construction in LINQ query

    - by Steffen
    I've got some objects which implement this interface: public interface IRow { void Fill(DataRow dr); } Usually when I select something out of db, I go: public IEnumerable<IRow> SelectSomeRows { DataTable table = GetTableFromDatabase(); foreach (DataRow dr in table.Rows) { IRow row = new MySQLRow(); // Disregard the MySQLRow type, it's not important row.Fill(dr); yield return row; } } Now with .Net 4, I'd like to use AsParallel, and thus LINQ. I've done some testing on it, and it speeds up things alot (IRow.Fill uses Reflection, so it's hard on the CPU) Anyway my problem is, how do I go about creating a LINQ query, which calls Fills as part of the query, so it's properly parallelized? For testing performance I created a constructor which took the DataRow as argument, however I'd really love to avoid this if somehow possible. With the constructor in place, it's obviously simple enough: public IEnumerable<IRow> SelectSomeRowsParallel { DataTable table = GetTableFromDatabase(); return from DataRow dr in table.Rows.AsParallel() select new MySQLRow(dr); } However like I said, I'd really love to be able to just stuff my Fill method into the LINQ query, and thus not need the constructor overload.

    Read the article

  • Project management: Implementing custom errors in VS compilation process

    - by David Lively
    Like many architects, I've developed coding standards through years of experience to which I expect my developers to adhere. This is especially a problem with the crowd that believes that three or four years of experience makes you a senior-level developer.Approaching this as a training and code review issue has generated limited success. So, I was thinking that it would be great to be able to add custom compile-time errors to the build process to more strictly enforce this and other guidelines. For instance, we use stored procedures for ALL database access, which provides procedure-level security, db encapsulation (table structure is hidden from the app), and other benefits. (Note: I am not interested in starting a debate about this.) Some developers prefer inline SQL or parametrized queries, and that's fine - on their own time and own projects. I'd like a way to add a compilation check that finds, say, anything that looks like string sql = "insert into some_table (col1,col2) values (@col1, @col2);" and generates an error or, in certain circumstances, a warning, with a message like Inline SQL and parametrized queries are not permitted. Or, if they use the var keyword var x = new MyClass(); Variable definitions must be explicitly typed. Do Visual Studio and MSBuild provide a way to add this functionality? I'm thinking that I could use a regular expression to find unacceptable code and generate the correct error, but I'm not sure what, from a performance standpoint, is the best way to to integrate this into the build process. We could add a pre- or post-build step to run a custom EXE, but how can I return line- and file-specifc errors? Also, I'd like this to run after compilation of each file, rather than post-link. Is a regex the best way to perform this type of pattern matching, or should I go crazy and run the code through a C# parser, which would allow node-level validation via the parse tree? I'd appreciate suggestions and tales of prior experience.

    Read the article

  • Game architecture: modeling different steps/types of UI

    - by Sander
    I have not done any large game development projects, only messed around with little toy projects. However, I never found an intuitive answer to a specific design question. Namely, how are different types/states of UI modeled in games? E.g. how is a menu represented? How is it different from a "game world" state (let's use an FPS as an example). How is an overlaid menu on top of a "game world" modeled? Let's imagine the main loop of a game. Where do the game states come into play? It it a simple case-by-case approach? if (menu.IsEnabled) menu.Process(elapsedTime); if (world.IsEnabled) world.Process(elapsedTime); if (menu.IsVisible) menu.Draw(); if (world.IsVisible) world.Draw(); Or are menu and world represented somewhere in a different logic layer and not represented at this level? (E.g. a menu is just another high-level entity like e.g. player input or enemy manager, equal to all others) foreach (var entity in game.HighLevelEntities) entity.Process(elapsedTime); foreach (var entity in game.HighLevelEntities) entity.Draw(elapsedTime); Are there well-known design patterns for this? Come to think of it, I don't know any game-specific design patterns - I assume there are others, as well? Please tell me about them.

    Read the article

  • Is it impossible to secure .net code (intellectual property) ?

    - by JL
    I used to work in JavaScript a lot and one thing that really bothered my employers was that the source code was too easy to steal. Even with obfuscation, nothing really helped, because we all knew that any competent developer would be able to read that code if they wanted to. JS Scripts are one thing, but what about SOA projects that have millions invested in IP (Intellectual Property). I love .net, and especially C#, but I recently again had to answer the question "If we give this compiled program over to our clients, can their developers reverse engineer it?" I had gone out of my way to obfuscate the code, but I knew it wouldn't take that much for another determined C# developer to get at the code. So I earnestly pose the question, is it impossible to secure .net code? The considerations I have as as follows: Even regular native executables can be reversed, but not every developer has the skill to be able to do this. Its a lot harder to disassemble a native executable than a .net assembly. Obfuscation will only get you so far, but it does help a little. Why have I never seen any public acknowledgement by Microsoft that anything written in .net is subject to relatively easy IP theft? Why have I never seen a scrap of counter measure training on any Microsoft site? Why does VS come with a community obfuscater as an optional component? Ok maybe I have just had my head in the sand here, but its not exactly high on most developers priority list. Are there any plans to address my concerns in any future version of .net? I'm not knocking .net, but I would like some realistic answers, thank you, question marked as subjective and community!

    Read the article

  • php simplexmlelement - I can access most properties (except the one with a dash?)

    - by Matthew Steiner
    So I run some code like this: $quote = simplexml_load_string($xml); $quote = $quote->Stock; echo 'Name: '; echo $quote->Name; echo '<br>'; echo 'Sybmol: '; echo $quote->Symbol; echo '<br>'; echo 'Last Price: '; echo $quote->Last; echo '<br>'; echo 'Earnings To Price Ratio: '; echo $quote->P-E; echo '<br>'; I know that the second to last line ($quote-P-E) is incorrect - I don't think you can use dashes like that. But for some reason I can't figure out how to access that property. The weird thing is that's how it's written if I var_dump($quote) (It's towards the end): object(SimpleXMLElement)#17 (16) { ["Symbol"]=> string(4) "AAPL" ["Last"]=> string(6) "271.87" ["Date"]=> string(9) "6/17/2010" ["Time"]=> string(6) "3:59pm" ["Change"]=> string(5) "+4.62" ["Open"]=> string(6) "270.72" ["High"]=> string(6) "272.90" ["Low"]=> string(6) "269.50" ["Volume"]=> string(8) "31195032" ["MktCap"]=> string(6) "247.4B" ["PreviousClose"]=> string(6) "267.25" ["PercentageChange"]=> string(6) "+1.73%" ["AnnRange"]=> string(15) "132.88 - 272.90" ["Earns"]=> string(6) "11.796" ["P-E"]=> string(5) "22.66" ["Name"]=> string(10) "Apple Inc." } How should I be accessing this attribute/property?

    Read the article

  • To implement a remote desktop sharing solution

    - by Cameigons
    Hi, I'm on planning/modeling phase to develop a remote desktop sharing solution, which must be web browser based. In other words: an user will be able to see and interact with someone's remote desktop using his web-browser. Everything the user who wants to share his desktop will need, besides his browser, is installing an add-in, which he's going to be prompted about when necessary. The add-in is required since (afaik) no browser technology allows desktop control from an app running within the browser alone. The add-in installation process must be as simple and transparent as possible to the user (similar to AdobeConnectNow, in case anyone's acquainted with it). The user can share his desktop with lots of people at the same time, but concede desktop control to only one of them at a time(makes no sense being otherwise). Project requirements: All technology employed must be open-source license compatible Both front ends are going to be in flash (browser) Must work on Linux, Windows XP(and later) and MacOSX. Must work at least with IE7(and later) and Firefox3.0(and later). At the very least, once the sharer's stream hits the server from where it'll be broadcast, hereon it must be broadcasted in flv (so I'm thinking whether to do the encoding at the client's machine (the one sharing the desktop) or send it in some other format to the server and encode it there). Performance and scalability are important: It must be able to handle hundreds of dozens of users(one desktop sharer, the rest viewers) We'll definitely be using red5. My doubts concern mostly implementing the desktop publisher side (add-in and streamer): 1) Are you aware of other projects that I could look into for ideas? (I'm aware of bigbluebutton.org and code.google.com/p/openmeetings) 2) Should I base myself on VNC ? 3) Bearing in mind the need to have it working cross-platform, what language should I go with? (My team is very used with java and I have some knowledge of C/C++, but anything goes really). 4) Any other advices are appreciated.

    Read the article

  • How to make std::vector's operator[] compile doing bounds checking in DEBUG but not in RELEASE

    - by Edison Gustavo Muenz
    I'm using Visual Studio 2008. I'm aware that std::vector has bounds checking with the at() function and has undefined behaviour if you try to access something using the operator [] incorrectly (out of range). I'm curious if it's possible to compile my program with the bounds checking. This way the operator[] would use the at() function and throw a std::out_of_range whenever something is out of bounds. The release mode would be compiled without bounds checking for operator[], so the performance doesn't degrade. I came into thinking about this because I'm migrating an app that was written using Borland C++ to Visual Studio and in a small part of the code I have this (with i=0, j=1): v[i][j]; //v is a std::vector<std::vector<int> > The size of the vector 'v' is [0][1] (so element 0 of the vector has only one element). This is undefined behaviour, I know, but Borland is returning 0 here, VS is crashing. I like the crash better than returning 0, so if I can get more 'crashes' by the std::out_of_range exception being thrown, the migration would be completed faster (so it would expose more bugs that Borland was hiding).

    Read the article

  • Simply doing modelType.ToString() isn't sufficient, How can i use it via Activator.CreateInstance?

    - by programmerist
    public class MyController { public object CreateByEnum(DataModelType modeltype) { string enumText = modeltype.ToString(); // will return for example "Company" Type classType = Type.GetType(enumText); // the Type for Company class object t = Activator.CreateInstance(classType); // create an instance of Company class return t; } } public class CompanyView { public static List<Personel> GetPersonel() { MyController controller = new MyController(); _Company company = controller.CreateByEnum(DataModelType.Company) as _Company; return company.GetPersonel(); } } public enum DataModelType { xyz, klm, tucyz, Company } Yes, I agree Activator.CreateInstance() is very useful. Unfortunately, I need to pass in the correct type. That means building the correct string to pass to Type.GetType(). If I trace through the call to Controller.CreatebyEnum() in the code I posted above, simply doing modelType.ToString() isn't sufficient, even for the case of DataModelType.Company. My solution'll be maintenance bottleneck. What would be better is something that takes the results of modelType.ToString() and then recursively searches through all the types found in all the assemblies loaded in the current AppDomain. According to MSDN, Type.GetType() only searches the current calling assembly, and mscorlib.dll. How can i do that? . i need best performance?

    Read the article

  • Convert a raw string to an array of big-endian words with Ruby

    - by Zag zag..
    Hello, I would like to convert a raw string to an array of big-endian words. As example, here is a JavaScript function that do it well (by Paul Johnston): /* * Convert a raw string to an array of big-endian words * Characters >255 have their high-byte silently ignored. */ function rstr2binb(input) { var output = Array(input.length >> 2); for(var i = 0; i < output.length; i++) output[i] = 0; for(var i = 0; i < input.length * 8; i += 8) output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32); return output; } I believe the Ruby equivalent can be String#unpack(format). However, I don't know what should be the correct format parameter. Thank you for any help. Regards

    Read the article

  • Technology and language for a stable Digital Audio Workstation development

    - by Kill KRT
    Hi, I'm designing a cross platform (Windows/Linux/OS X) application, something like a digital audio workstation. I'd like to create a software where users have a fully featured sequencer (multiple tracks with automation) and where it is possible to create instruments using a visual language (as Pure Data/Max MSP). Ehm... I know that I've already posted a question about a related issue... But in order to decide which technology I should use, I think I'd better to make more investigation. I'm a quite experted user of audio trackers (Renoise, Protracker,...) and sequencers (FL Studio, Cubase 5), but I didn't ever try to develop even a basic audio tracker. I know just the basic theory of mixing sound and know how basically a DSP works. My questions are: Where I can find a good tutorial/guide/book about this issue? Do you think using C# (with NAudio) could dramatically reduce performance? I know C++ would be the best choice, but I find C# so elegant and easy to build and port, while C++ is so powerful and fast, but there are too #define and bad things for my taste! ;-) Thank you.

    Read the article

  • What's the most efficient way to setup a multi-lingual website

    - by Jasper De Bruijn
    Hi, I'm developing a website that will be available in different languages. It is a LAMP (Linux, Apache, MySQL, PHP) setup, and it makes use of Smarty, mostly for the template engine. The way we currently translate is by a self-written smarty plugin, which will recognize certain tags in the HTML files, and will find the corresponding tag in an earlier defined language file. The HTML could look as follows: <p>Hi, welcome to $#gamedesc;!</p> And the language file could look like this: gamedesc:Poing 2009$; welcome:this is another tag$; Which would then output <p>Hi, welcome to Poing 2009!</p> This system is very basic, but it is pretty hard to control, if I f.e. would like to keep track of what has been translated so far, or give certain users the rights to translate only certain tags. I've been looking at some alternative ways to approach this, by either replacing the text-file with XML files which could store some extra meta-data, or by perhaps storing all the texts in the database, and retrieving it there. My question is, what would be the best way to make this system both maintainable and perform well with high user-traffic? Are there perhaps any (lightweight) plugins I could take a look at?

    Read the article

  • java GC periodically enters into several full GC cycles

    - by Peter
    Environment: sun JDK 1.6.0_16 vm settings: -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -Xms1024 -Xmx1024M -XX:MaxNewSize=448m -XX:NewSize=448m -XX:SurvivorRatio=4(6 also checked) -XX:MaxPermSize=128M OS: windows server 2003 processor: 4 cores of INTEL XEON 5130, 2000 Hz my application description: high intensity of concurrent(java 5 concurrency used) operations completed each time by commit to oracle. it's about 20-30 threads run non stop, doing tasks. application runs in JBOSS web container. My GC starts work normally, I see a lot of small GCs and all that time CPU shows good load, like all 4 cores loaded to 40-50%, CPU graph is stable. Then , after 1 min of good work, CPU starts drop to 0% on 2 cores from 4, it's graph becomes unstable, goes up and down("teeth"). I see, that my threads work slower(I have monitoring), I see that GC starts produce a lot of FULL GC during that time and next 4-5 minutes this situation remains as is, then for short period of time, like 1 minute, it gets back to normal situation, but shortly after that all bad thing repeats. Question: Why I have so frequent full GC??? How to prevent that? I played with SurvivorRatio - does not help. I noticed, that application behaves normally until first FULL GC occurs, while I have enough memory. Then it runs badly. my GC LOG: starts good then long period of FULL GCs(many of them) 1027.861: [GC 942200K-623526K(991232K), 0.0887588 secs] 1029.333: [GC 803279K(991232K), 0.0927470 secs] 1030.551: [GC 967485K-625549K(991232K), 0.0823024 secs] 1030.634: [GC 625957K(991232K), 0.0763656 secs] 1033.126: [GC 969613K-632963K(991232K), 0.0850611 secs] 1033.281: [GC 649899K(991232K), 0.0378358 secs] 1035.910: [GC 813948K(991232K), 0.3540375 secs] 1037.994: [GC 967729K-637198K(991232K), 0.0826042 secs] 1038.435: [GC 710309K(991232K), 0.1370703 secs] 1039.665: [GC 980494K-972462K(991232K), 0.6398589 secs] 1040.306: [Full GC 972462K-619643K(991232K), 3.7780597 secs] 1044.093: [GC 620103K(991232K), 0.0695221 secs] 1047.870: [Full GC 991231K-626514K(991232K), 3.8732457 secs] 1053.739: [GC 942140K(991232K), 0.5410483 secs] 1056.343: [Full GC 991232K-634157K(991232K), 3.9071443 secs] 1061.257: [GC 786274K(991232K), 0.3106603 secs] 1065.229: [Full GC 991232K-641617K(991232K), 3.9565638 secs] 1071.192: [GC 945999K(991232K), 0.5401515 secs] 1073.793: [Full GC 991231K-648045K(991232K), 3.9627814 secs] 1079.754: [GC 936641K(991232K), 0.5321197 secs]

    Read the article

  • What effects has working in rotating shifts on programming teams?

    - by eKek0
    I work in a bank, and the boss now want's that we, the programming team, work on rotating shifts. He wants that sometimes we work from 7am to 3pm, and sometimes on 11.30am to 7.30pm. He says that we will be more productive working this way, because he has worked with teams just like that and he just knows that. Nobody of the team wants this change, but we don't know how to effectively reject this new rule. I was trying to find some empirical (or almost) evidence about how rotating shifts affects performance of programming teams, and I couldn't. I had read something about rotating shifts, but not exactly about the effect of this on programming teams. Do you know any research about rotating shifts on programming teams? Did you have any experience with this kind of work? EDIT: Other teams of the company, like the database administrators team, the help desk team, the communication team or the network administrators team are already working in rotating shifts, and they don't like this but they do it anyway. I think the boss want that we work on rotating shifts too because of them, but since only we do programming I think the effects of rotating shifts could be, at least, different for us.

    Read the article

  • DSP - Filter sweep effect

    - by Trap
    I'm implementing a 'filter sweep' effect (I don't know if it's called like that). What I do is basically create a low-pass filter and make it 'move' along a certain frequency range. To calculate the filter cut-off frequency at a given moment I use a user-provided linear function, which yields values between 0 and 1. My first attempt was to directly map the values returned by the linear function to the range of frequencies, as in cf = freqRange * lf(x). Although it worked ok it looked as if the sweep ran much faster when moving through low frequencies and then slowed down during its way to the high frequency zone. I'm not sure why is this but I guess it's something to do with human hearing perceiving changes in frequency in a non-linear manner. My next attempt was to move the filter's cut-off frequency in a logarithmic way. It works much better now but I still feel that the filter doesn't move at a constant perceived speed through the range of frequencies. How should I divide the frequency space to obtain a constant perceived sweep speed? Thanks in advance.

    Read the article

  • Should java try blocks be scoped as tightly as possible?

    - by isme
    I've been told that there is some overhead in using the Java try-catch mechanism. So, while it is necessary to put methods that throw checked exception within a try block to handle the possible exception, it is good practice performance-wise to limit the size of the try block to contain only those operations that could throw exceptions. I'm not so sure that this is a sensible conclusion. Consider the two implementations below of a function that processes a specified text file. Even if it is true that the first one incurs some unnecessary overhead, I find it much easier to follow. It is less clear where exactly the exceptions come from just from looking at statements, but the comments clearly show which statements are responsible. The second one is much longer and complicated than the first. In particular, the nice line-reading idiom of the first has to be mangled to fit the readLine call into a try block. What is the best practice for handling exceptions in a funcion where multiple exceptions could be thrown in its definition? This one contains all the processing code within the try block: void processFile(File f) { try { // construction of FileReader can throw FileNotFoundException BufferedReader in = new BufferedReader(new FileReader(f)); // call of readLine can throw IOException String line; while ((line = in.readLine()) != null) { process(line); } } catch (FileNotFoundException ex) { handle(ex); } catch (IOException ex) { handle(ex); } } This one contains only the methods that throw exceptions within try blocks: void processFile(File f) { FileReader reader; try { reader = new FileReader(f); } catch (FileNotFoundException ex) { handle(ex); return; } BufferedReader in = new BufferedReader(reader); String line; while (true) { try { line = in.readLine(); } catch (IOException ex) { handle(ex); break; } if (line == null) { break; } process(line); } }

    Read the article

  • Postgres error with Sinatra/Haml/DataMapper on Heroku

    - by sevennineteen
    I'm trying to move a simple Sinatra app over to Heroku. Migration of the Ruby app code and existing MySQL database using Taps went smoothly, but I'm getting the following Postgres error: PostgresError - ERROR: operator does not exist: text = integer LINE 1: ...d_at", "post_id" FROM "comments" WHERE ("post_id" IN (4, 17,... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts. It's evident that the problem is related to a type mismatch in the query, but this is being issued from a Haml template by the DataMapper ORM at a very high level of abstraction, so I'm not sure how I'd go about controlling this... Specifically, this seems to be throwing up on a call of p.comments from my Haml template, where p represents a given post. The Datamapper models are related as follows: class Post property :id, Serial ... has n, :comments end class Comment property :id, Serial ... belongs_to :post end This works fine on my local and current hosted environment using MySQL, but Postgres is clearly more strict. There must be hundreds of Datamapper & Haml apps running on Postgres DBs, and this model relationship is super-conventional, so hopefully someone has seen (and determined how to fix) this. Thanks!

    Read the article

  • iPhone: Using dispatch_after to mimick NSTimer

    - by Joseph Tura
    Don't know a whole lot about blocks. How would you go about mimicking a repeating NSTimer with dispatch_after? My problem is that I want to "pause" a timer when the app moves to the background, but subclassing NSTimer does not seem to work. I tried something which seems to work. I cannot judge its performance implications or whether it could be greatly optimized. Any input is welcome. #import "TimerWithPause.h" @implementation TimerWithPause @synthesize timeInterval; @synthesize userInfo; @synthesize invalid; @synthesize invocation; + (TimerWithPause *)scheduledTimerWithTimeInterval:(NSTimeInterval)aTimeInterval target:(id)aTarget selector:(SEL)aSelector userInfo:(id)aUserInfo repeats:(BOOL)aTimerRepeats { TimerWithPause *timer = [[[TimerWithPause alloc] init] autorelease]; timer.timeInterval = aTimeInterval; NSMethodSignature *signature = [[aTarget class] instanceMethodSignatureForSelector:aSelector]; NSInvocation *aInvocation = [NSInvocation invocationWithMethodSignature:signature]; [aInvocation setSelector:aSelector]; [aInvocation setTarget:aTarget]; [aInvocation setArgument:&timer atIndex:2]; timer.invocation = aInvocation; timer.userInfo = aUserInfo; if (!aTimerRepeats) { timer.invalid = YES; } [timer fireAfterDelay]; return timer; } - (void)fireAfterDelay { dispatch_time_t delay = dispatch_time(DISPATCH_TIME_NOW, self.timeInterval * NSEC_PER_SEC); dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_after(delay, queue, ^{ [invocation performSelectorOnMainThread:@selector(invoke) withObject:nil waitUntilDone:NO]; if (!invalid) { [self fireAfterDelay]; } }); } - (void)invalidate { invalid = YES; [invocation release]; invocation = nil; [userInfo release]; userInfo = nil; } - (void)dealloc { [self invalidate]; [super dealloc]; } @end

    Read the article

  • How to eliminate tearing from animation?

    - by MusiGenesis
    I'm running an animation in a WinForms app at 18.66666... frames per second (it's synced with music at 140 BPM, which is why the frame rate is weird). Each cel of the animation is pre-calculated, and the animation is driven by a high-resolution multimedia timer. The animation itself is smooth, but I am seeing a significant amount of "tearing", or artifacts that result from cels being caught partway through a screen refresh. When I take the set of cels rendered by my program and write them out to an AVI file, and then play the AVI file in Windows Media Player, I do not see any tearing at all. I assume that WMP plays the file smoothly because it uses DirectX (or something else) and is able to synchronize the rendering with the screen's refresh activity. It's not changing the frame rate, as the animation stays in sync with the audio. Is this why WMP is able to render the animation without tearing, or am I missing something? Is there any way I can use DirectX (or something else) in order to enable my program to be aware of where the current scan line is, and if so, is there any way I can use that information to eliminate tearing without actually using DirectX for displaying the cels? Or do I have to fully use DirectX for rendering in order to deal with this problem? Update: forgot a detail. My app renders each cell onto a PictureBox using Graphics.DrawImage. Is this significantly slower than using BitBlt, such that I might eliminate at least some of the tearing by using BitBlt?

    Read the article

< Previous Page | 658 659 660 661 662 663 664 665 666 667 668 669  | Next Page >