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  • PHP: Strange Date Problem

    - by Me-and-Coding
    Hi, I have two users in my database whose birth date is set to: 1985-01-26 And then i have function which when provided the users' date, tells how many days are left in the birthday. Here is the function: function retage($iy,$im,$id) { if(!empty($iy)>0 && intval($im)>0 && intval($id)>0) { $tdo=$iy.'-'.$im.'-'.$id; $tdc=date('Y').'-'.$im.'-'.$id; /*echo "<br/>";*/ $cd=date('Y-n-j'); /*echo "<br/>";*/ if(strtotime($tdc)>strtotime($cd))//coming { $ty=floor((strtotime($tdc)-strtotime($tdo))/(3600*24*365)); $td=floor((strtotime($tdc)-strtotime($cd))/(24*3600)); if($td==1) { $td=round((strtotime($tdc)-strtotime($cd))/(24*3600)).' day to go'; } else { $td=round((strtotime($tdc)-strtotime($cd))/(24*3600)).' days to go'; } $ty='<font color="#C7C5C5">is turning '.$ty.' on <br>'.date('M jS Y',strtotime($tdc)).'</font>'; //return 'is turning '.$ty.' on '.$tdc; } elseif(strtotime($tdc)<strtotime($cd))//past { $ty=floor((strtotime($tdc)-strtotime($tdo))/(3600*24*365)); if($ty>0) { //$td='gone '.floor((strtotime($cd)-strtotime($tdc))/(24*3600)).' days ago'; $ndays=floor((strtotime($cd)-strtotime($tdc))/(24*3600)); if($ndays==1) $td=' gone '.round((strtotime($cd)-strtotime($tdc))/(24*3600)).' day ago'; else $td=' gone '.round((strtotime($cd)-strtotime($tdc))/(24*3600)).' days ago'; $ty='<font color="#C7C5C5">had turned '.$ty.' on <br>'.date('M jS Y',strtotime($tdc)).'</font>'; //return 'had turned '.$ty.' on '.$tdc; } else { $tdc=(date('Y')+1).'-'.$im.'-'.$id; $ty=floor((strtotime($tdc)-strtotime($tdo))/(3600*24*365)); //$td=floor((strtotime($tdc)-strtotime($cd))/(24*3600)).' days to go'; $td=floor((strtotime($tdc)-strtotime($cd))/(24*3600)); if($td==1) { $td=round((strtotime($tdc)-strtotime($cd))/(24*3600)).' day to go'; } else { $td=round((strtotime($tdc)-strtotime($cd))/(24*3600)).' days to go'; } $ty='<font color="#C7C5C5">is turning '.$ty.' on <br>'.date('M jS Y',strtotime($tdc)).'</font>'; //return 'is turning '.$ty.' on '.$tdc; } } else//today { $ty=floor((strtotime($tdc)-strtotime($tdo))/(3600*24*365)); if($ty>0) { $td='today'; $ty='<font color="#C7C5C5">has turned <br>'.$ty.' on today </font>'; //return 'has turned '.$ty.' on today'; } else { $ty='<font color="#C7C5C5">today</font>';$td=''; //return ''; } } } else { $ty='';$td=''; //return ''; } $ta[0]=$ty; $ta[1]=$td ; return $ta; } I use below code to show the days remaining: while($rs=mysql_fetch_array($result)) { if (isset($rs['byear'],$rs['bmonth'],$rs['bdate'])) { $tmptxt = retage($rs['byear'],$rs['bmonth'],$rs['bdate']); echo $tmptxt[1]; } } The strange thing is that for one user, the days remaining is shown correctly eg: gone 120 days ago And for other user having same birth date, this is shown: Jan 1st 1970 -14755 days to go Strange: When I use the same function outside of the loop and test with date 1985-01-26, the correct result is shown. Note: You can check out the function for yourself. Could you please tell what could be wrong there, your help will be highly appreciated. Thanks.

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  • Way in over my head! (Dealing with better programmers)

    - by darkman
    I've just been hired to be part of a group that is developing in C++. Before, I've been coding on and off at my job for the past 11 years (some C, some Fortran, some C++). The coding I've done was mostly maintaining and adding new features to one of our systems. The code, being 10 years old, did not contain all the modern C++ stuff. Lo and behold, my new job is filled with programmers with 5-10 years experience of pure coding and they all use the most modern aspects of C++ (C++11, template, lambda, etc, etc). They are expecting someone with that same experience... Well, I've been working for 15 years total but when I looked at their code, I couldn't understand half of it! :-| Anyone been in that situation? What would you recommend?

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  • How can I decrease my C# learning curve? [closed]

    - by MSU
    I have been learning programming, mostly C# and .net stuff. And I have target to become a fulltime .NET developer. But I am feeling that learning Graph is very slow, I have been learning C# programming, doing some coding everyday, but how I can learn very fast and increase my skills rapidly? I know there should be a balance of coding and reading, as without reading I can't code and without coding I can't increase my skills. SO, I am requesting here suggesting from experts on how I bring more pace to my learning curve? I intend to give 4-6 hours daily for this and on weekends 10+ hours.

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  • How do I efficiently code both the client and server at the same time?

    - by liamzebedee
    I'm coding my game using a client-server model. When playing on singleplayer, the game starts a local server, and interacts with it just like a remote server (multiplayer). I have done this to avoid coding separate singleplayer and multiplayer code. I have just started coding and have encountered a major problem. Currently I'm developing the game in Eclipse, having all the game classes organized into packages. Then, in my server code, I just use all the classes in the client packages. The problem is, these client classes have variables that are specific to rendering, which obviously wouldn't be performed on a server. Should I create modified versions of the client classes to use in the server? Or should I just modify the client classes with a boolean, to indicate if its the client/server using it. Are there any other options I have? I just had a thought about maybe using the server class as the core class, then extending it with rendering stuff?

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  • how to resolve/normalize URLs in GWT/Javascript?

    - by Limbic System
    Given two URLs, how can I resolve one of them against the other? I'm trying to emulate Java's URI.resolve(), which does not exist in GWT's emulation library. I've had to implement this manually, which, as you might expect has been very error-prone. Is there a GWT or Javascript library for resolving or normalizing URLs?

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  • Why did visual programming never take off and what future paradigms might change that?

    - by Rego
    As the number of "visual" OS's such as Android, iOS and the promised Windows 8 are becoming more popular, it does not seem to me that we programmers have new ways to code using these new technologies, due to a possible lack in new visual programming languages paradigms. I've seen several discussions about incompatibilities between the current coding development environment, and the new OS approaches from Windows 8, Android and other tablets OS's. I mean, today if we have a new tablet, it's almost a requirement for coding, to have, for instance, an external keyboard (due it seems to me it's very difficult to program using the touch screen), exactly because the coding assistance is not conceived to "write" thousands of lines of code. So, how advanced should be the "new" visual programming languages paradigms? Which characteristics these new paradigms would be required?

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  • Ubuntu 13.XX unable to mount USB HDD. Tried everything. I/O error boot sector/file system

    - by XaviGG
    I know that there are many posts related but none of them helped me. I will jump to the last test because it is the one that should work, but it does not. An external HDD with single partition slow NTFS formatted in Windows, empty and clean. Checked for errors, it tells that not errors where found. Moving to Ubutnu 13.04... Gparted throws the first error when trying to read the disk: Input/output error It appears as unknown the content of the disk. Unable to create partition table or format it, getting the same error when trying. If I try to mount it in the terminal it tells me the same, specifying that also there is an I/O error reading the boot sector. I have this problem since I upgraded (always with fresh install) to 13.04. I thought it will be solved by the 13.10 but it has the same behavior. I tried with two different HDD (HD and SSHD) that work perfectly in Windows 7. In 13.04 at least I got a trying of mounting where the icon of the drive started showing and disappearing until finally it disappeared. But now it doesn't even try. Possible causes: -The HDD was my old main HDD, so it had WIN,RECOVERY,SYSTEM,UBU,SWAP partitions. Maybe the way or place where the partition table is defined is not the best for an external HDD but I don't know a lot in that topic. I would appreciate a lot if someone can give me a guideline to convert one of these HDD in a working external HDD. No files to recover, nothing to care about. Just format completely the disk and be able to use it for storing backups without having to move the files first to the windows partition, load windows and then copy them to the external HDD. Because I want to use a file comparator for the backups. Thanks a lot Edit 1: I found an option in Windows to convert it to a dynamic HDD that warns me that I wont be able to run O.S. after changing. I suppose that is what I need because in the current mode I cannot safely extract it. But it tells me an error that it couldn't change the mode.

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  • How to find an array from parent array

    - by Me-and-Coding
    Hi, I am using below code to find an array inside parent array but it is not working that is retuning empty even though the specified key exits in the parent array. $cards_parent = $feedData['BetradarLivescoreData']['Sport']['Category']['Tournament']['Match']; $cards = array(); foreach($cards_parent as $key => $card) { if ($key === 'Cards') { $cards[] = $cards_parent[$key]; break; } } Do you know any array function that will search parent array for specified key and if found it will create an array starting from that key. Thanks

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  • How to implement GCM in Google AppEngine?

    - by Broken System
    I'm a PHP Developer and Web Designer. In my work a partner asked me if I could set up a Google Cloud Messaging server. I read the documentation but couldn't find a clear tutorial to set up this server. I got no knowleadge about Java so it makes my job harder. I could "compile" a war file using ant as GCM Demo Tutorial says. But I can't deploy it to my AppEngine server to try it out (It's my first time using AppEngine too). Could you give me some steps to create my own GCM server? Sorry about my bad english. Thanks!

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  • Admin auto generation

    - by Me-and-Coding
    Hi, I create custom CMS sites and then go ahead for the backend/admin side. Is there any tool out there to automatically create admin side of my sites, for example, based on table relationships or whatever customization we may put in place. PHPMaker seems to claim something like what i ask for but i have not used it. Any tool out there to auto-create admin side or PHPMaker is up to the point? Thanks

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  • Adding Days To Date in SQL

    - by Coding Noob
    I am trying to get data from my Database of those who have upcoming birth days in next few days(declared earlier) it's working fine for days but this query will not work if i add 24 days to current date cause than it will need change in month. i wonder how can i do it declare @date int=10, @month int=0 select * from STUDENT_INFO where DATEPART(DD,STDNT_DOB) between DATEPART(DD,GETDATE()) and DATEPART(DD,DATEADD(DD,@date,GETDATE())) and DATEPART(MM,STDNT_DOB) = DATEPART(MM,DATEADD(MM,@month,GETDATE())) This query works fine but it only checks date between 8 & 18 but if i use it like this declare @date int=30, @month int=0 select * from STUDENT_INFO where DATEPART(DD,STDNT_DOB) between DATEPART(DD,GETDATE()) and DATEPART(DD,DATEADD(DD,@date,GETDATE())) and DATEPART(MM,STDNT_DOB) = DATEPART(MM,DATEADD(MM,@month,GETDATE())) it will return nothing since it require addition in month as well If I Use it like this declare @date int=40, @month int=0 select * from STUDENT_INFO where DATEPART(DD,STDNT_DOB) between DATEPART(DD,GETDATE()) and DATEADD(DD,@date,GETDATE()) and DATEPART(MM,STDNT_DOB) = DATEPART(MM,DATEADD(MM,@month,GETDATE())) than it will return results till the last of this month but will not show till 18/12 which was required

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  • How can I lower my C# learning curve? [closed]

    - by MSU
    I have been learning programming, mostly C# and .net stuff. And I have target to become a fulltime .NET developer. But I am feeling that learning Graph is very slow, I have been learning C# programming, doing some coding everyday, but how I can learn very fast and increase my skills rapidly? I know there should be a balance of coding and reading, as without reading I can't code and without coding I can't increase my skills. SO, I am requesting here suggesting from experts on how I bring more pace to my learning curve? I intend to give 4-6 hours daily for this and on weekends 10+ hours.

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  • How Do You Test Your Software ?

    - by Kubi
    I'm currently working on 2 software projects: A Social Networking Web Site for an NGO A Patient Management System for a hospital Although I've been programming for 5 years, I can't just say that I'm very good at testing or Test Driven Designing an application. How would you arrange your Software Testing before coding phase, during coding and after you finished the coding phase for a. providing stakeholders with information about the quality of the product or service under test. b. providing an objective, independent view of the software to allow the business to appreciate and understand the risks of software implementation. and how do you understand that your program/application/product c. meets the business and technical requirements that guided its design and development d. works as expected p.s. please feel free to edit the question since my english is not very powerful.

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  • Mysql query help needed

    - by Me-and-Coding
    Hi, i have two tables category and hotels where category.id should be equal to hotels.catid. Now how do i select 3 rows from each different category from the hotels table. I have this query: select h.* from hotels h inner join category c on h.catid = c.id order by h.catid, h.hid this selects all records, but i want to select three rows per different category so in all it should return 9 rows with 3 rows for each category. If this can not be done in mysql, you could also suggest php code please. Thanks

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  • Unable to delete inherited entity class in EF4

    - by Coding Gorilla
    I have two entities in an EF4 model (using Model First), let's call them EntityA and EntityB. EntityA is marked as abstract, and EntityB inherits from EntityA. They are similar to the following: public class EntityA { public Guid Id; public string Name; public string Uri; } public class EntityB : EntityA { public string AnotherProperty; } The generated database tables look as I would expect them, with EntityA as on table, and then another table like: EntityA_EntityB Id (PK, FK, uniqueidentifier) AnotherProperty (varchar) There is a foreign key constraint on EntityA_EntityB that references EntityA's Id property, no cascades are configured (although I did try changing these myself). The problem is that when I attempt to do something like: Context.DeleteObject(EntityA_EntityB); EF attempts to delete the EntityA_EntityB table record before deleting the EntityA table record, which of course violates the foreign key constraint on EntityA_EntityB table. Using EFProfiler I see the following commands being sent to the database: delete [dbo].[EntityA_EntityB] where (([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) followed by delete [dbo].[EntityA] where ([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) I'm completely stumped as to how to get around this problem. I would think the EF should know that it needs to delete the base class first, before deleting the inherited class. I know I could do some triggers or other database type solutions, but I'd rather avoid doing that if I can. All my classes are POCO built using some customized T4 templates. I don't want to paste in a lot of extraneous code, but if you need more information I'll provide what I can.

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  • Can Tiny C compiler be used for Open CV code compiling?

    - by Enjoy coding
    Hi Gurus, I am new to OpenCV and I have only Tiny C compiler configured on my Windows XP machine. Can I use this tiny C compiler to compile opencv programs for image manipulations. I have alredy installed python2.6 and opencv2.0 on my windows xp pc. If we can compile how can we do that? I tried on net but found nothing of use.. Please help.

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  • Can Visual Studio Express run from USB drive?

    - by system PAUSE
    Using an arbitrary Windows machine (2000/XP or later), I can install Eclipse CDT to a USB drive move that USB drive onto a different Windows machine--one that does not have any form of Eclipse software already installed, and potentially a different version of Windows (but 2000/XP or later) use Eclipse to develop application-level C/C++ programs on that second machine (and that includes using the debugger), running directly from the USB drive without copying anything to C:. I can do all this without having Administrator privileges on either machine. I can do the same with NetBeans, and with several other IDEs that support C/C++ development. Is it possible to do this with any version of Visual Studio Express? If not, can you explain the technical reason(s) this doesn't work?

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  • SQL Scenario of allocating ids to user

    - by Enjoy coding
    Hi, I have an sql scenario as follows which I have been trying to improve. There is a table 'Returns' which is having ids of the returned goods against a shop for an item. Its structure is as below. Returns ------------------------- Return ID | Shop | Item ------------------------- 1 Shop1 Item1 2 Shop1 Item1 3 Shop1 Item1 4 Shop1 Item1 5 Shop1 Item1 There is one more table Supplier with Shop, supplier and Item as shown below. Supplier --------------------------------- Supplier | Shop | Item | Volume --------------------------------- supp1 Shop1 Item1 20% supp2 Shop1 Item1 80% Now as you see supp1 is supplying 20 % of total item1 volume and supp2 is supplying 80% of Item1 to shop1. And there were 5 return of items against the same Item1 for same Shop1. Now I need to allocate any four return IDs to Supp1 and remaining one return Id to supp2. This allocation of numbers is based on the ratio of the supplied volume percentage of the supplier. This allocation varies depending on the ratio of volume of supplied items. Now I have tried a method of using RANKs as shown below by use of temp tables. temp table 1 will have Shop, Return Id, Item, Total count of return IDs and Rank of the return id. temp table 2 will have shop, Supplier, Item and his proportion and rank of proportion. Now I am facing the difficulty in allocating top return ids to top supplier as illustrated above. As SQL doesnt have loops how can I achieve this. I have been tying several ways of doing this. Please advice. My environment is Teradata (ANSI SQL is enough). Thanks in advance.

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  • Any dynamic database frontend tool from which you can update directly?

    - by Enjoy coding
    Hi Gurus, This is with reference to this question where I got one tabular report format. I need to update the user entered values correctly back to the same table rows. I am in the process of doing this by using general form post data methods by using some logics which I think will not be easy to maintain. So, just out of curiosity, Is there a front end creator javascript libraries or frameworks which can create the front end for any query's resultset and updates the corresponding rows when the user updates them from front end. This need not have all the full functionality, any one usable, customizable thing will reduce the code maintenance problems. I have googled for some javascript libraris for this but not able to get which will be suitable. Please suggest any useful tools. My environment is Mysql, PHP, JQuery, XAMPP server on Windows. Is JQuery provides one. Thanks in advance.

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  • jQuery setinterval does not show first element

    - by Me-and-Coding
    Hi, I am creating this content slider, you can view/edit here: http://jsbin.com/esame4 I have put in place setInterval so that animation runs automatically, however, when it is run for the first time, google image is shown but not afterwords. Should be simple but i am unable to figure out the problem.

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  • Merging multiple docx files to one

    - by coding
    I am developing a desktop application in C#. I have coded a function to merge multiple docx files but it does not work as expected. I don't get the content exactly as how it was in the source files. A few blank lines are added in between. The content extends to the next pages, header and footer information is lost, page margins gets changed, etc.. How can I concatenate docs as it is without and change in it.Any suggestions will be helpful. This is my code. public bool CombineDocx(string[] filesToMerge, string destFilepath) { Application wordApp = null; Document wordDoc = null; object outputFile = destFilepath; object missing = Type.Missing; object pageBreak = WdBreakType.wdPageBreak; try { wordApp = new Application { DisplayAlerts = WdAlertLevel.wdAlertsNone, Visible = false }; wordDoc = wordApp.Documents.Add(ref missing, ref missing, ref missing, ref missing); Selection selection = wordApp.Selection; foreach (string file in filesToMerge) { selection.InsertFile(file, ref missing, ref missing, ref missing, ref missing); selection.InsertBreak(ref pageBreak); } wordDoc.SaveAs( ref outputFile, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing); return true; } catch (Exception ex) { Msg.Log(ex); return false; } finally { if (wordDoc != null) { wordDoc.Close(); } if (wordApp != null) { wordApp.DisplayAlerts = WdAlertLevel.wdAlertsAll; wordApp.Quit(); Marshal.FinalReleaseComObject(wordApp); } } }

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  • Performance Optimization &ndash; It Is Faster When You Can Measure It

    - by Alois Kraus
    Performance optimization in bigger systems is hard because the measured numbers can vary greatly depending on the measurement method of your choice. To measure execution timing of specific methods in your application you usually use Time Measurement Method Potential Pitfalls Stopwatch Most accurate method on recent processors. Internally it uses the RDTSC instruction. Since the counter is processor specific you can get greatly different values when your thread is scheduled to another core or the core goes into a power saving mode. But things do change luckily: Intel's Designer's vol3b, section 16.11.1 "16.11.1 Invariant TSC The time stamp counter in newer processors may support an enhancement, referred to as invariant TSC. Processor's support for invariant TSC is indicated by CPUID.80000007H:EDX[8]. The invariant TSC will run at a constant rate in all ACPI P-, C-. and T-states. This is the architectural behavior moving forward. On processors with invariant TSC support, the OS may use the TSC for wall clock timer services (instead of ACPI or HPET timers). TSC reads are much more efficient and do not incur the overhead associated with a ring transition or access to a platform resource." DateTime.Now Good but it has only a resolution of 16ms which can be not enough if you want more accuracy.   Reporting Method Potential Pitfalls Console.WriteLine Ok if not called too often. Debug.Print Are you really measuring performance with Debug Builds? Shame on you. Trace.WriteLine Better but you need to plug in some good output listener like a trace file. But be aware that the first time you call this method it will read your app.config and deserialize your system.diagnostics section which does also take time.   In general it is a good idea to use some tracing library which does measure the timing for you and you only need to decorate some methods with tracing so you can later verify if something has changed for the better or worse. In my previous article I did compare measuring performance with quantum mechanics. This analogy does work surprising well. When you measure a quantum system there is a lower limit how accurately you can measure something. The Heisenberg uncertainty relation does tell us that you cannot measure of a quantum system the impulse and location of a particle at the same time with infinite accuracy. For programmers the two variables are execution time and memory allocations. If you try to measure the timings of all methods in your application you will need to store them somewhere. The fastest storage space besides the CPU cache is the memory. But if your timing values do consume all available memory there is no memory left for the actual application to run. On the other hand if you try to record all memory allocations of your application you will also need to store the data somewhere. This will cost you memory and execution time. These constraints are always there and regardless how good the marketing of tool vendors for performance and memory profilers are: Any measurement will disturb the system in a non predictable way. Commercial tool vendors will tell you they do calculate this overhead and subtract it from the measured values to give you the most accurate values but in reality it is not entirely true. After falling into the trap to trust the profiler timings several times I have got into the habit to Measure with a profiler to get an idea where potential bottlenecks are. Measure again with tracing only the specific methods to check if this method is really worth optimizing. Optimize it Measure again. Be surprised that your optimization has made things worse. Think harder Implement something that really works. Measure again Finished! - Or look for the next bottleneck. Recently I have looked into issues with serialization performance. For serialization DataContractSerializer was used and I was not sure if XML is really the most optimal wire format. After looking around I have found protobuf-net which uses Googles Protocol Buffer format which is a compact binary serialization format. What is good for Google should be good for us. A small sample app to check out performance was a matter of minutes: using ProtoBuf; using System; using System.Diagnostics; using System.IO; using System.Reflection; using System.Runtime.Serialization; [DataContract, Serializable] class Data { [DataMember(Order=1)] public int IntValue { get; set; } [DataMember(Order = 2)] public string StringValue { get; set; } [DataMember(Order = 3)] public bool IsActivated { get; set; } [DataMember(Order = 4)] public BindingFlags Flags { get; set; } } class Program { static MemoryStream _Stream = new MemoryStream(); static MemoryStream Stream { get { _Stream.Position = 0; _Stream.SetLength(0); return _Stream; } } static void Main(string[] args) { DataContractSerializer ser = new DataContractSerializer(typeof(Data)); Data data = new Data { IntValue = 100, IsActivated = true, StringValue = "Hi this is a small string value to check if serialization does work as expected" }; var sw = Stopwatch.StartNew(); int Runs = 1000 * 1000; for (int i = 0; i < Runs; i++) { //ser.WriteObject(Stream, data); Serializer.Serialize<Data>(Stream, data); } sw.Stop(); Console.WriteLine("Did take {0:N0}ms for {1:N0} objects", sw.Elapsed.TotalMilliseconds, Runs); Console.ReadLine(); } } The results are indeed promising: Serializer Time in ms N objects protobuf-net   807 1000000 DataContract 4402 1000000 Nearly a factor 5 faster and a much more compact wire format. Lets use it! After switching over to protbuf-net the transfered wire data has dropped by a factor two (good) and the performance has worsened by nearly a factor two. How is that possible? We have measured it? Protobuf-net is much faster! As it turns out protobuf-net is faster but it has a cost: For the first time a type is de/serialized it does use some very smart code-gen which does not come for free. Lets try to measure this one by setting of our performance test app the Runs value not to one million but to 1. Serializer Time in ms N objects protobuf-net 85 1 DataContract 24 1 The code-gen overhead is significant and can take up to 200ms for more complex types. The break even point where the code-gen cost is amortized by its faster serialization performance is (assuming small objects) somewhere between 20.000-40.000 serialized objects. As it turned out my specific scenario involved about 100 types and 1000 serializations in total. That explains why the good old DataContractSerializer is not so easy to take out of business. The final approach I ended up was to reduce the number of types and to serialize primitive types via BinaryWriter directly which turned out to be a pretty good alternative. It sounded good until I measured again and found that my optimizations so far do not help much. After looking more deeper at the profiling data I did found that one of the 1000 calls did take 50% of the time. So how do I find out which call it was? Normal profilers do fail short at this discipline. A (totally undeserved) relatively unknown profiler is SpeedTrace which does unlike normal profilers create traces of your applications by instrumenting your IL code at runtime. This way you can look at the full call stack of the one slow serializer call to find out if this stack was something special. Unfortunately the call stack showed nothing special. But luckily I have my own tracing as well and I could see that the slow serializer call did happen during the serialization of a bool value. When you encounter after much analysis something unreasonable you cannot explain it then the chances are good that your thread was suspended by the garbage collector. If there is a problem with excessive GCs remains to be investigated but so far the serialization performance seems to be mostly ok.  When you do profile a complex system with many interconnected processes you can never be sure that the timings you just did measure are accurate at all. Some process might be hitting the disc slowing things down for all other processes for some seconds as well. There is a big difference between warm and cold startup. If you restart all processes you can basically forget the first run because of the OS disc cache, JIT and GCs make the measured timings very flexible. When you are in need of a random number generator you should measure cold startup times of a sufficiently complex system. After the first run you can try again getting different and much lower numbers. Now try again at least two times to get some feeling how stable the numbers are. Oh and try to do the same thing the next day. It might be that the bottleneck you found yesterday is gone today. Thanks to GC and other random stuff it can become pretty hard to find stuff worth optimizing if no big bottlenecks except bloatloads of code are left anymore. When I have found a spot worth optimizing I do make the code changes and do measure again to check if something has changed. If it has got slower and I am certain that my change should have made it faster I can blame the GC again. The thing is that if you optimize stuff and you allocate less objects the GC times will shift to some other location. If you are unlucky it will make your faster working code slower because you see now GCs at times where none were before. This is where the stuff does get really tricky. A safe escape hatch is to create a repro of the slow code in an isolated application so you can change things fast in a reliable manner. Then the normal profilers do also start working again. As Vance Morrison does point out it is much more complex to profile a system against the wall clock compared to optimize for CPU time. The reason is that for wall clock time analysis you need to understand how your system does work and which threads (if you have not one but perhaps 20) are causing a visible delay to the end user and which threads can wait a long time without affecting the user experience at all. Next time: Commercial profiler shootout.

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