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  • Interface and partial classes

    - by Tomek Tarczynski
    According to rule SA1201 in StyleCop elements in class must appear in correct order. The order is following: Fields Constructors Finalizers (Destructors) Delegates Events Enums Interfaces Properties Indexers Methods Structs Classes Everything is ok, except of Interfaces part, because Interface can contain mehtods, events, properties etc... If we want to be strict about this rule then we won't have all members of Interface in one place which is often very useful. According to StyleCop help this problem can be solved by spliting class into partial classes. Example: /// <summary> /// Represents a customer of the system. /// </summary> public partial class Customer { // Contains the main functionality of the class. } /// <content> /// Implements the ICollection class. /// </content> public partial class Customer : ICollection { public int Count { get { return this.count; } } public bool IsSynchronized { get { return false; } } public object SyncRoot { get { return null; } } public void CopyTo(Array array, int index) { throw new NotImplementedException(); } } Are there any other good solutions to this problem?

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  • loading data from file into 2d array

    - by Chris
    I am just starting with perl and would like some help with arrays please. I am reading lines from a data file and splitting the line into fields: open (INFILE, $infile); do { my $linedata = <INFILE>; my @data= split ',',$linedata; .... } until eof; I then want to store the individual field values (in @data) in and array so that the array looks like the input data file ie, the first "row" of the array contains the first line of data from INFILE etc. Each line of data from the infile contains 4 values, x,y,z and w and once the data are all in the array, I have to pass the array into another program which reads the x,y,z,w and displays the w value on a screen at the point determined by the x,y,z value. I can not pas the data to the other program on a row-by-row basis as the program expects the data to in a 2d matrtix format. Any help greatly appreciated. Chris

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  • Looping through JSON arrays

    - by George
    I'm trying to pull the field names in the header of some JSON output. The following is a sample of the JSON header info: {"HEADER":{"company":{"label":"Company Name"},"streetaddress":{"label":"Street Address"},"ceo":{"label":"CEO Name","fields":{"firstname":{"label":"First Name"},"lastname":{"label":"Last Name"}}} I'm able to loop through the header and output the field and label (i.e. company and Company Name) using the following code: obj = JSON.parse(jsonResponse); for (var key in obj.HEADER) { response.write ( obj.HEADER[key].label ); response.write ( key ); } but can't figure out how to loop through and output the sub array of fields (i.e. firstname and First Name). Any ideas?

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  • How do I break down MySQL query results into categories, each with a specific number of rows?

    - by Mel
    Hello, Problem: I want to list n number of games from each genre (order not important) The following MySQL query resides inside a ColdFusion function. It is meant to list all games under a platform (for example, list all PS3 games; list all Xbox 360 games; etc...). The variable for PlatformID is passed through the URL. I have 9 genres, and I would like to list 10 games from each genre. SELECT games.GameID AS GameID, games.GameReleaseDate AS rDate, titles.TitleName AS tName, titles.TitleShortDescription AS sDesc, genres.GenreName AS gName, platforms.PlatformID, platforms.PlatformName AS pName, platforms.PlatformAbbreviation AS pAbbr FROM (((games join titles on((games.TitleID = titles.TitleID))) join genres on((genres.GenreID = games.GenreID))) join platforms on((platforms.PlatformID = games.PlatformID))) WHERE (games.PlatformID = '#ARGUMENTS.PlatformID#') ORDER BY GenreName ASC, GameReleaseDate DESC Once the query results come back I group them in ColdFusion as follows: <cfoutput query="ListGames" group="gName"> (first loop which lists genres) #ListGames.gName# <cfoutput> (nested loop which lists games) #ListGames.tName# </cfoutput> </cfoutput> The problem is that I only want 10 games from each genre to be listed. If I place a "limit" of 50 in the SQL, I will get ~ 50 games of the same genre (depending on how much games of that genre there are). The second issue is I don't want the overload of querying the database for all games when each person will only look at a few. What is the correct way to do this? Many thanks!

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  • Re-Initialize RAID-0 in software after card failure

    - by Ben
    I'm working on a Friend's WD MyBook "1TB" HDD that is not mounting. When I got in to it, I discovered that it is really 2 500GB HDD's set up as RAID-0. It appears that the drives themselves are fine, but that the logic board has failed. My questions is this: can I re-initialize the RAID-0 using software RAID so that I can recover the data to another drive? If so, how and which software RAID would be best (Preferably open source. any platform OK).

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  • Domain Validation in a CQRS architecture

    - by Jupaol
    Basically I want to know if there is a better way to validate my domain entities. This is how I am planning to do it but I would like your opinion The first approach I considered was: class Customer : EntityBase<Customer> { public void ChangeEmail(string email) { if(string.IsNullOrWhitespace(email)) throw new DomainException(“...”); if(!email.IsEmail()) throw new DomainException(); if(email.Contains(“@mailinator.com”)) throw new DomainException(); } } I actually do not like this validation because even when I am encapsulating the validation logic in the correct entity, this is violating the Open/Close principle (Open for extension but Close for modification) and I have found that violating this principle, code maintenance becomes a real pain when the application grows up in complexity. Why? Because domain rules change more often than we would like to admit, and if the rules are hidden and embedded in an entity like this, they are hard to test, hard to read, hard to maintain but the real reason why I do not like this approach is: if the validation rules change, I have to come and edit my domain entity. This has been a really simple example but in RL the validation could be more complex So following the philosophy of Udi Dahan, making roles explicit, and the recommendation from Eric Evans in the blue book, the next try was to implement the specification pattern, something like this class EmailDomainIsAllowedSpecification : IDomainSpecification<Customer> { private INotAllowedEmailDomainsResolver invalidEmailDomainsResolver; public bool IsSatisfiedBy(Customer customer) { return !this.invalidEmailDomainsResolver.GetInvalidEmailDomains().Contains(customer.Email); } } But then I realize that in order to follow this approach I had to mutate my entities first in order to pass the value being valdiated, in this case the email, but mutating them would cause my domain events being fired which I wouldn’t like to happen until the new email is valid So after considering these approaches, I came out with this one, since I am going to implement a CQRS architecture: class EmailDomainIsAllowedValidator : IDomainInvariantValidator<Customer, ChangeEmailCommand> { public void IsValid(Customer entity, ChangeEmailCommand command) { if(!command.Email.HasValidDomain()) throw new DomainException(“...”); } } Well that’s the main idea, the entity is passed to the validator in case we need some value from the entity to perform the validation, the command contains the data coming from the user and since the validators are considered injectable objects they could have external dependencies injected if the validation requires it. Now the dilemma, I am happy with a design like this because my validation is encapsulated in individual objects which brings many advantages: easy unit test, easy to maintain, domain invariants are explicitly expressed using the Ubiquitous Language, easy to extend, validation logic is centralized and validators can be used together to enforce complex domain rules. And even when I know I am placing the validation of my entities outside of them (You could argue a code smell - Anemic Domain) but I think the trade-off is acceptable But there is one thing that I have not figured out how to implement it in a clean way. How should I use this components... Since they will be injected, they won’t fit naturally inside my domain entities, so basically I see two options: Pass the validators to each method of my entity Validate my objects externally (from the command handler) I am not happy with the option 1 so I would explain how I would do it with the option 2 class ChangeEmailCommandHandler : ICommandHandler<ChangeEmailCommand> { public void Execute(ChangeEmailCommand command) { private IEnumerable<IDomainInvariantValidator> validators; // here I would get the validators required for this command injected, and in here I would validate them, something like this using (var t = this.unitOfWork.BeginTransaction()) { var customer = this.unitOfWork.Get<Customer>(command.CustomerId); this.validators.ForEach(x =. x.IsValid(customer, command)); // here I know the command is valid // the call to ChangeEmail will fire domain events as needed customer.ChangeEmail(command.Email); t.Commit(); } } } Well this is it. Can you give me your thoughts about this or share your experiences with Domain entities validation EDIT I think it is not clear from my question, but the real problem is: Hiding the domain rules has serious implications in the future maintainability of the application, and also domain rules change often during the life-cycle of the app. Hence implementing them with this in mind would let us extend them easily. Now imagine in the future a rules engine is implemented, if the rules are encapsulated outside of the domain entities, this change would be easier to implement

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  • Detect car acceleration in Android app?

    - by Stud33
    I want to incorporate some Accelerometer code into a Android application im working and want to see if this is possible. Basically what I need is for the code to detect car acceleration motion. I am not wanting to determine speed with the code but just distinguish if the phone is in a car and has accelerated motion (Hence the car is moving for the first time). I have gone through many different accelerometer applications to see if this motion produces a viable profile to go off of and it appears it does. Just looking for something that popups a "Hello World" dialog when it detects your in the car and its moving for the first time down the street. Any help would be appreciated and a simple yes or no its possible would work. I would also be interested in compensating anyone that is capable of doing this as well. I need this done like yesterday so please let me know. Thank You, JTW

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  • Objective C Array and Object Release

    - by david
    Hi, I have a newbie question regarding when to release the elements of a NSArray. See following pseudo code: NSMutalbeArray *2DArray = [[NSMutableArray alloc] initWithCapacity:10]; for (int i=0;i<10;i++) { NSMutableArray *array = [[MSMutableArray alloc] initWithCapacity:5]; for (int j=0;j<5;j++) { MyObject *obj = [[MyObject alloc] init]; [array addObject:obj]; [obj release]; } [2DArray addObject:array]; [array release]; } // use 2DArray to do something [2DArray release] My question here is, when I release 2DArray, do I need to explicitly release each of its element (array) first? Also, before I release the "array" object, do I need to release each of its element (MyObject) first? I am new to Objective C. Please help. thanks.

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  • MySQL - How do I inner join sorting the joined data

    - by Gary
    I'm trying to write a report which will join a person, their work, and their hourly wage at the time of work. I cannot seem to figure out the best way to join the person's cost when the date is less than the date of the work. Let's say a person cost $30 per hour at the start of the year then got a $10 raise o Feb 5 and another on Mar 1. 01/01/2010 $30.00 (per hour) 02/05/2010 $40.00 03/01/2010 $45.00 The person put in hours several days which span the rasies. 01/05/2010 10 hours (should be at $30/hr) 01/27/2010 5 hours (again at $30) 02/10/2010 10 hours (at $40/hr) 03/03/2010 5 hours (at $45/hr) I'm trying to write one SQL statement which will pull the hours, the cost per hour, and the hours*cost. The cost is the hourly rate last entered into the system so the cost date is less than the work date, ordered by cost date limit 1. SELECT person.id, person.name, work.hours, person_costs.value, work.hours * person_costs.value AS value FROM person INNER JOIN work ON (person.id = work.person_id) INNER JOIN person_costs ON (person.id = person_costs.person_id AND person_costs.date < work.date) WHERE person.id = 1234 ORDER BY work.date ASC The problem I'm having, the person_costs isn't ordered by date in descending order. It's pulling out "any" value (naturally sorted by record position) which matches the condition. How do I select the first person_cost value which is older than the work date? Thanks!

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  • Select dynamic string has a different value when referenced in Where clause

    - by David
    I dynamically select a string built using another string. So, if string1='David Banner', then MyDynamicString should be 'DBanne' Select ... , Left( left((select top 1 strval from dbo.SPLIT(string1,' ')) //first word ,1) //first character + (select top 1 strval from dbo.SPLIT(string1,' ') //second word where strval not in (select top 1 strval from dbo.SPLIT(string1,' '))) ,6) //1st character of 1st word, followed by up to 5 characters of second word [MyDynamicString] ,... From table1 Join table2 on table1pkey=table2fkey Where MyDynamicString <> table2.someotherfield I know table2.someotherfield is not equal to the dynamic string. However, when I replace MyDynamicString in the Where clause with the full left(left(etc.. function, it works as expected. Can I not reference this string later in the query? Do I have to build it using the left(left(etc.. function each time in the where clause?

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  • populating a list from another worksheet with 1 criteria

    - by Arcadian
    Hello, here is my dilemma. I have two worksheets one that has the name of clients and one that i want to copy the names to depending on the city. For instance: associated to each column is last name, first name and city. i have hundreds of names associated to different cities and what i would like is from worksheet1.xls to copy all the New York clients to worksheet2.xls either when i open worksheet2 or via macro what ever is easier and because last name is in one cell and the first name is in the other i would have to copy both. I saw that its possible to link cells from one worksheet to another and then do a vlookup depending on the criteria. Is that the best easiest way or is there another? thanks in advance and cheers oleg

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  • error by creating process

    - by Tyzak
    hello i want to get startet with programming with WIN32, therefore i wrote a programm that creates a process but in the line of code where i create the process the programm gets an error an dosn't work (abend). i don't know if the code in programm 1 is wrong or the code in the second programm that should be created by the first. ( I don't know if the code in the first programm after "createprocess" is right because i didn't get further with debugging, because in this line i get the error.(i tested it without the cout,waitforobject and close handle but i didn't work either )). First Programm: #include <iostream> #include <windows.h> #include <string> using namespace std; void main() { bool ret; bool retwait; STARTUPINFO startupinfo; GetStartupInfo (&startupinfo); PROCESS_INFORMATION pro2info; ret = CreateProcess(NULL, L"D:\\betriebssystemePRA1PRO2.exe", NULL, NULL, false, CREATE_NEW_CONSOLE, NULL, NULL, &startupinfo, &pro2info); cout<<"hProcess: "<<pro2info.hProcess<<endl; cout<<"dwProcessId: "<<pro2info.dwProcessId <<endl; retwait= WaitForSingleObject (pro2info.hProcess, 100); retwait= WaitForSingleObject (pro2info.hProcess, 100); CloseHandle (pro2info.hProcess);//prozesshandle schließen retwait= WaitForSingleObject (pro2info.hProcess, 100); ExitProcess(0); } Seconde Programm: #include <iostream> #include <windows.h> #include <string> using namespace std; void main() { int b; b=GetCurrentProcessId(); cout<<b<<endl; cout<<"Druecken Sie Enter zum Beenden"<<endl; cin.get(); //warten bis Benutzer bestätigt Sleep (700); ExitProcess(0); cout<<"test"; } Thanks in advance

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  • Accessing Spring beans from a Tiles view (JSP)

    - by Sinuhe
    In Spring MVC I can access my beans in JSP using JstlView's exposedContextBeanNames (or exposeContextBeansAsAttributes). For example, then, in my JSP I can write (${properties.myProperty). But when the same JSP is a part of a tiles view, these properties aren't accessible. Is possible to configure Tiles properly or access these properties in another way? I'm using Spring MVC 3.0.2 and Tiles 2.2.1. Here's a bit of my configuration: <bean id="tilesViewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="order" value="1"/> <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" /> </bean> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="order" value="2"/> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/> <property name="exposedContextBeanNames"> <list><value>properties</value></list> </property> </bean>

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  • How to use will_paginate with a nested resource in Rails?

    - by Sue Petersen
    I'm new to Rails, and I'm having major trouble getting will_paginate to work with a nested resource. I have two models, Statement and Invoice. will_paginate is working on Statement, but I can't get it to work on Invoice. I know I'd doing something silly, but I can't figure it out and the examples I've found on google won't work for me. statement.rb class Statement < ActiveRecord::Base has_many :invoices def self.search(search, page) paginate :per_page => 19, :page => page, :conditions => ['company like ?', "%#{search}%"], :order => 'date_due DESC, company, supplier' end end statements_controller.rb <irrelevant code clipped for readability> def index #taken from the RAILSCAST 51, will_paginate podcast @statements = Statement.search(params[:search], params[:page]) end I call this in the view like so, and it works: <%= will_paginate @statements %> But I can't figure out how to get it to work for Invoices: invoice.rb class Invoice < ActiveRecord::Base belongs_to :statement def self.search(search, page) paginate :per_page => 19, :page => page, :conditions => ['company like ?', "%#{search}%"], :order => 'employee' end end invoices_controller.rb class InvoicesController < ApplicationController before_filter :find_statement #TODO I can't get will_paginate to work w a nested resource def index #taken from the RAILSCAST 51, will_paginate podcast @invoices = Invoice.search(params[:search], params[:page]) end def find_statement @statement_id = params[:statement_id] return(redirect_to(statements_url)) unless @statement_id @statement = Statement.find(@statement_id) end end And I try to call it like this: <%= will_paginate (@invoices) % The most common error message, as I play with this, is: "The @statements variable appears to be empty. Did you forget to pass the collection object for will_paginate?" I don't have a clue what the problem is, or how to fix it. Thanks for any help and guidance!

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  • Problems using wxWidgets (wxMSW) within multiple DLL instances

    Preface I'm developing VST-plugins which are DLL-based software modules and loaded by VST-supporting host applications. To open a VST-plugin the host applications loads the VST-DLL and calls an appropriate function of the plugin while providing a native window handle, which the plugin can use to draw it's GUI. I managed to port my original VSTGUI code to the wxWidgets-Framework and now all my plugins run under wxMSW and wxMac but I still have problems under wxMSW to find a correct way to open and close the plugins and I am not sure if this is a wxMSW-only issue. Problem If I use any VST-host application I can open and close multiple instances of one of my VST-plugins without any problems. As soon as I open another of my VST-plugins besides my first VST-plugin and then close all instances of my first VST-plugin the application crashes after a short amount of time within the wxEventHandlerr::ProcessEvent function telling me that the wxTheApp object isn't valid any longer during execution of wxTheApp-FilterEvent (see below). So it seems to be that the wxTheApp objects was deleted after closing all instances of the first plugin and is no longer available for the second plugin. bool wxEvtHandler::ProcessEvent(wxEvent& event) { // allow the application to hook into event processing if ( wxTheApp ) { int rc = wxTheApp->FilterEvent(event); if ( rc != -1 ) { wxASSERT_MSG( rc == 1 || rc == 0, _T("unexpected wxApp::FilterEvent return value") ); return rc != 0; } //else: proceed normally } .... } Preconditions 1.) All my VST-plugins a dynamically linked against the C-Runtime and wxWidgets libraries. With regard to the wxWidgets forum this seemed to be the best way to run multiple instances of the software side by side. 2.) The DllMain of each VST-Plugin is defined as follows: // WXW #include "wx/app.h" #include "wx/defs.h" #include "wx/gdicmn.h" #include "wx/image.h" #ifdef __WXMSW__ #include <windows.h> #include "wx/msw/winundef.h" BOOL APIENTRY DllMain ( HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved ) { switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: { wxInitialize(); ::wxInitAllImageHandlers(); break; } case DLL_THREAD_ATTACH: break; case DLL_THREAD_DETACH: break; case DLL_PROCESS_DETACH: wxUninitialize(); break; } return TRUE; } #endif // __WXMSW__ class Application : public wxApp {}; IMPLEMENT_APP_NO_MAIN(Application) Question How can I prevent this behavior respectively how can I properly handle the wxTheApp object if I have multiple instances of different VST-plugins (DLL-modules), which are dynamically linked against the C-Runtime and wxWidgets libraries? Best reagards, Steffen

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  • ASP.NET MVC 2 DisplayFor()

    - by ZombieSheep
    I'm looking at the new version of ASP.NET MVC (see here for more details if you haven't seen it already) and I'm having some pretty basic trouble displaying the content of an object. In my control I have an object of type "Person", which I am passing to the view in ViewData.Model. All is well so far, and I can extact the object in the view ready for display. What I don't get, though, is how I need to call the Html.DisplayFor() method in order to get the data to screen. I've tried the following... <% MVC2test.Models.Person p = ViewData.Model as MVC2test.Models.Person; %> // snip <%= Html.DisplayFor(p => p) %> but I get the following message: CS0136: A local variable named 'p' cannot be declared in this scope because it would give a different meaning to 'p', which is already used in a 'parent or current' scope to denote something else I know this is not what I should be doing - I know that redefining a variable will producte this error, but I don't know how to access the object from the controller. So my question is, how do I pass the object to the view in order to display its properties? (I should add that I am reading up on this in my limited spare time, so it is entirely possible I have missed something fundamental) TIA

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  • Can I spead out a long running stored proc accross multiple CPU's?

    - by Russ
    [Also on SuperUser - http://superuser.com/questions/116600/can-i-spead-out-a-long-running-stored-proc-accross-multiple-cpus] I have a stored procedure in SQL server the gets, and decrypts a block of data. ( Credit cards in this case. ) Most of the time, the performance is tolerable, but there are a couple customers where the process is painfully slow, taking literally 1 minute to complete. ( Well, 59377ms to return from SQL Server to be exact, but it can vary by a few hundred ms based on load ) When I watch the process, I see that SQL is only using a single proc to perform the whole process, and typically only proc 0. Is there a way I can change my stored proc so that SQL can multi-thread the process? Is it even feasible to cheat and to break the calls in half, ( top 50%, bottom 50% ), and spread the load, as a gross hack? ( just spit-balling here ) My stored proc: USE [Commerce] GO /****** Object: StoredProcedure [dbo].[GetAllCreditCardsByCustomerId] Script Date: 03/05/2010 11:50:14 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [dbo].[GetAllCreditCardsByCustomerId] @companyId UNIQUEIDENTIFIER, @DecryptionKey NVARCHAR (MAX) AS SET NoCount ON DECLARE @cardId uniqueidentifier DECLARE @tmpdecryptedCardData VarChar(MAX); DECLARE @decryptedCardData VarChar(MAX); DECLARE @tmpTable as Table ( CardId uniqueidentifier, DecryptedCard NVarChar(Max) ) DECLARE creditCards CURSOR FAST_FORWARD READ_ONLY FOR Select cardId from CreditCards where companyId = @companyId and Active=1 order by addedBy desc --2 OPEN creditCards --3 FETCH creditCards INTO @cardId -- prime the cursor WHILE @@Fetch_Status = 0 BEGIN --OPEN creditCards DECLARE creditCardData CURSOR FAST_FORWARD READ_ONLY FOR select convert(nvarchar(max), DecryptByCert(Cert_Id('Oh-Nay-Nay'), EncryptedCard, @DecryptionKey)) FROM CreditCardData where cardid = @cardId order by valueOrder OPEN creditCardData FETCH creditCardData INTO @tmpdecryptedCardData -- prime the cursor WHILE @@Fetch_Status = 0 BEGIN print 'CreditCardData' print @tmpdecryptedCardData set @decryptedCardData = ISNULL(@decryptedCardData, '') + @tmpdecryptedCardData print '@decryptedCardData' print @decryptedCardData; FETCH NEXT FROM creditCardData INTO @tmpdecryptedCardData -- fetch next END CLOSE creditCardData DEALLOCATE creditCardData insert into @tmpTable (CardId, DecryptedCard) values ( @cardId, @decryptedCardData ) set @decryptedCardData = '' FETCH NEXT FROM creditCards INTO @cardId -- fetch next END select CardId, DecryptedCard FROM @tmpTable CLOSE creditCards DEALLOCATE creditCards

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  • Modelling boost::Lockable with semaphore rather than mutex (previously titled: Unlocking a mutex fr

    - by dan
    I'm using the C++ boost::thread library, which in my case means I'm using pthreads. Officially, a mutex must be unlocked from the same thread which locks it, and I want the effect of being able to lock in one thread and then unlock in another. There are many ways to accomplish this. One possibility would be to write a new mutex class which allows this behavior. For example: class inter_thread_mutex{ bool locked; boost::mutex mx; boost::condition_variable cv; public: void lock(){ boost::unique_lock<boost::mutex> lck(mx); while(locked) cv.wait(lck); locked=true; } void unlock(){ { boost::lock_guard<boost::mutex> lck(mx); if(!locked) error(); locked=false; } cv.notify_one(); } // bool try_lock(); void error(); etc. } I should point out that the above code doesn't guarantee FIFO access, since if one thread calls lock() while another calls unlock(), this first thread may acquire the lock ahead of other threads which are waiting. (Come to think of it, the boost::thread documentation doesn't appear to make any explicit scheduling guarantees for either mutexes or condition variables). But let's just ignore that (and any other bugs) for now. My question is, if I decide to go this route, would I be able to use such a mutex as a model for the boost Lockable concept. For example, would anything go wrong if I use a boost::unique_lock< inter_thread_mutex for RAII-style access, and then pass this lock to boost::condition_variable_any.wait(), etc. On one hand I don't see why not. On the other hand, "I don't see why not" is usually a very bad way of determining whether something will work. The reason I ask is that if it turns out that I have to write wrapper classes for RAII locks and condition variables and whatever else, then I'd rather just find some other way to achieve the same effect. EDIT: The kind of behavior I want is basically as follows. I have an object, and it needs to be locked whenever it is modified. I want to lock the object from one thread, and do some work on it. Then I want to keep the object locked while I tell another worker thread to complete the work. So the first thread can go on and do something else while the worker thread finishes up. When the worker thread gets done, it unlocks the mutex. And I want the transition to be seemless so nobody else can get the mutex lock in between when thread 1 starts the work and thread 2 completes it. Something like inter_thread_mutex seems like it would work, and it would also allow the program to interact with it as if it were an ordinary mutex. So it seems like a clean solution. If there's a better solution, I'd be happy to hear that also. EDIT AGAIN: The reason I need locks to begin with is that there are multiple master threads, and the locks are there to prevent them from accessing shared objects concurrently in invalid ways. So the code already uses loop-level lock-free sequencing of operations at the master thread level. Also, in the original implementation, there were no worker threads, and the mutexes were ordinary kosher mutexes. The inter_thread_thingy came up as an optimization, primarily to improve response time. In many cases, it was sufficient to guarantee that the "first part" of operation A, occurs before the "first part" of operation B. As a dumb example, say I punch object 1 and give it a black eye. Then I tell object 1 to change it's internal structure to reflect all the tissue damage. I don't want to wait around for the tissue damage before I move on to punch object 2. However, I do want the tissue damage to occur as part of the same operation; for example, in the interim, I don't want any other thread to reconfigure the object in such a way that would make tissue damage an invalid operation. (yes, this example is imperfect in many ways, and no I'm not working on a game) So we made the change to a model where ownership of an object can be passed to a worker thread to complete an operation, and it actually works quite nicely; each master thread is able to get a lot more operations done because it doesn't need to wait for them all to complete. And, since the event sequencing at the master thread level is still loop-based, it is easy to write high-level master-thread operations, as they can be based on the assumption that an operation is complete when the corresponding function call returns. Finally, I thought it would be nice to use inter_thread mutex/semaphore thingies using RAII with boost locks to encapsulate the necessary synchronization that is required to make the whole thing work.

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  • How to Filter more than one field using WPF AutoCompleteBox

    - by Drew
    i am trying to customize the suggestions on the AutoCompleteBox in the WPF Tool kit. Right now i have a last name field which when the user enters characters a query runs that retrieves the top 10 records based on that last name. i would also like to filter by first name, i tried splitting out the comma and searching by the last name and the characters entered in the first name. however, as soon as a space or comma is entered into the autocompletebox, the suggest functionality stops working, which I believe is because the ValueMemberPath property is set to be last name. Is there a work around for this, or a way to modify the ValueMemberPath to handle multiple values? Thanks!

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  • Sorting an XML in Java

    - by Java Guy
    Hello I have an XML similiar to below, which needed to be sorted using the date field. <root> <Node1><date></date></Node1> <Node1><date></date></Node1> <Node1> <date></date></Node1> <Node1> <date></date></Node1> <Node2> <date></date></Node2> <Node2> <date></date></Node2> <Node2> <date></date></Node2> <Node2> <date></date> </Node2> </root> I would like to sort the XML based on the date(say asc order), irrespective of whether the date is under Node1 or Node2. Actually in Java code I have two seperate lists, one with Node1 objects and other with Node2 obects. I can sort the list in any order sperately inside java. But I need to have the dates sorted irrespective of the nodes it is apperaing on the XML. What is the best approach to sort this way in Java? Actaully I am using Castor for marshalling the java objects to XML. If you know this can be done with Castor, that will be great!

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  • Jquery Ajax Call In For Loop Only Runs Once - Possible Issue with Timing & Exit Condition?

    - by Grumps
    Background I'm building a form that uses autocomplete against the EchoNest API. First the users picks an artist, using the Artist Suggest call. Next they select a song but the Song and/Or Artist song search doesn't provide a "wild card" search. It only returns exact matches. So based on the forums they suggest building an array of the songs and using auto complete on the array. I can only get a maximum of 100 responses at a time. I do know based on the initial response the number of songs. My Plan: Wrap the ajax call in a for loop ('runonceloop'). Amend the loop exit condition after the first response with the total number of songs. Challenge I'm having: The 'runonceloop' only completes a singe loop because or at least that's what I believe: The exit condition is satisfied before the first response [1] is received. I've tried to adjust the 'exit condition' and 'counter' such that they are set and and increased at the end of the success block. This seems to lock up my browser. Can someone provide some guidance on this situation?[2] I'd really appreciate it. I also don't think turning async off is a good idea because it locks the browser. Response[1]: { "response": { "status": { "code": "0", "message": "Success", "version": "4.2" }, "start": 0, "total": 121, //Used for "songs": [ { "id": "SOXZYYG127F3E1B7A2", "title": "Karma police" }, { "id": "SOXZABD127F3E1B7A2", "title" : "Creep" } ] } } } Code[2] var songsList = []; function getSongs() { var numsongs = 2; //at least 2 runs. var startindex = 0; runonceloop: //<~~~~Referenced in question for (var j = 0;j >= numsongs;) { console.log('numsongs' + numsongs); $.ajax({ url: "http://developer.echonest.com/api/v4/artist/songs", dataType: "jsonp", data: { results: 100, api_key: "XXXXXXXXXXX", format: "jsonp", name: $("#artist").val(), start: startindex }, success: function (data) { var songs = data.response.songs; numsongs = data.response.total; //modify exit condition for (var i = 0; i < songs.length; i++) { songsList.push(songs[i].title); } j +=100;// increase by 100 to match number of responses. } }); }};

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  • JAXB does not call setter when unmarshalling objects

    - by Yaneeve
    Hi all, I am using JAXB 2.0 JDK 6 in order to unmarshall an XML instance into POJOs. In order to add some custom validation I have inserted a validation call into the setter of a property, yet despite it being private, it seems that the unmarshaller does not call the setter but directly modifies the private field. It is crucial to me that the custom validation occurs for this specific field every unmarshall call. What should I do? Code: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "LegalParams", propOrder = { "value" }) public class LegalParams { private static final Logger LOG = Logger.getLogger(LegalParams.class); @XmlTransient private LegalParamsValidator legalParamValidator; public LegalParams() { try { WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext(); LegalParamsFactory legalParamsFactory = (LegalParamsFactory) webApplicationContext.getBean("legalParamsFactory"); HttpSession httpSession = SessionHolder.getInstance().get(); legalParamValidator = legalParamsFactory.newLegalParamsValidator(httpSession); } catch (LegalParamsException lpe) { LOG.warn("Validator related error occurred while attempting to construct a new instance of LegalParams"); throw new IllegalStateException("LegalParams creation failure", lpe); } catch (Exception e) { LOG.warn("Spring related error occurred while attempting to construct a new instance of LegalParams"); throw new IllegalStateException("LegalParams creation failure", e); } } @XmlValue private String value; /** * Gets the value of the value property. * * @return * possible object is * {@link String } * */ public String getValue() { return value; } /** * Sets the value of the value property. * * @param value * allowed object is * {@link String } * @throws TestCaseValidationException * */ public void setValue(String value) throws TestCaseValidationException { legalParamValidator.assertValid(value); this.value = value; } }

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  • Slow MySQL Query not using filesort

    - by Canadaka
    I have a query on my homepage that is getting slower and slower as my database table grows larger. tablename = tweets_cache rows = 572,327 this is the query I'm currently using that is slow, over 5 seconds. SELECT * FROM tweets_cache t WHERE t.province='' AND t.mp='0' ORDER BY t.published DESC LIMIT 50; If I take out either the WHERE or the ORDER BY, then the query is super fast 0.016 seconds. I have the following indexes on the tweets_cache table. PRIMARY published mp category province author So i'm not sure why its not using the indexes since mp, provice and published all have indexes? Doing a profile of the query shows that its not using an index to sort the query and is using filesort which is really slow. possible_keys = mp,province Extra = Using where; Using filesort I tried adding a new multie-colum index with "profiles & mp". The explain shows that this new index listed under "possible_keys" and "key", but the query time is unchanged, still over 5 seconds. Here is a screenshot of the profiler info on the query. http://i355.photobucket.com/albums/r469/canadaka_bucket/slow_query_profile.png Something weird, I made a dump of my database to test on my local desktop so i don't screw up the live site. The same query on my local runs super fast, milliseconds. So I copied all the same mysql startup variables from the server to my local to make sure there wasn't some setting that might be causing this. But even after that the local query runs super fast, but the one on the live server is over 5 seconds. My database server is only using around 800MB of the 4GB it has available. here are the related my.ini settings i'm using default-storage-engine = MYISAM max_connections = 800 skip-locking key_buffer = 512M max_allowed_packet = 1M table_cache = 512 sort_buffer_size = 4M read_buffer_size = 4M read_rnd_buffer_size = 16M myisam_sort_buffer_size = 64M thread_cache_size = 8 query_cache_size = 128M # Try number of CPU's*2 for thread_concurrency thread_concurrency = 8 # Disable Federated by default skip-federated key_buffer = 512M sort_buffer_size = 256M read_buffer = 2M write_buffer = 2M key_buffer = 512M sort_buffer_size = 256M read_buffer = 2M write_buffer = 2M

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  • Advantage of using a smartfox server

    - by Fahim Akhter
    Hi, we are trying to outsource the server side of our game applicaton to someone. They recommend using http://www.smartfoxserver.com/ instead of our traditional php/mysql combination. Our game is in actionscript and will be using social aspects of facebook later on. Smartfoxserver is supposed to reduce the time of development. The thing I'm having a hard time getting right now is how? How does it reduce the time. We will still be making a RDMS writing stored procedures and game logic based server scripts. Where does smartfox come into play? Thanks, Fahim.

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