Search Results

Search found 2715 results on 109 pages for 'lazy initialization'.

Page 67/109 | < Previous Page | 63 64 65 66 67 68 69 70 71 72 73 74  | Next Page >

• What's the proper way to use sqlite at xCode?

  - by Elliot Chen

  Hi, Experts: Can you please give some suggestions on sqlite using at xcode? Within my application, I use a sqlite DB to store all local data. Two methods can be used to retrieve those data during running time. 1, Load all the data into memory at initialization stage. (More memory used, less DB open/close operation needed) 2, Read corresponding records when necessary, free the occupied memory after using. (Good habit for memory using, but much DB open/close operations needs). I prefer to use method 2, but not sure whether too many DB opening/closing operations could affect app's efficiency. Or do you think I can 'upgrade' method 2 by opening DB when app launches and closing DB when app quits? Thanks for your suggestions very much!

  Read the article

• Printf is not printing anything to output? C++ SDL

  - by Qasim

  I am trying to use "printf" in my Visual C++ project however it is not working. Using Lazy Foo's tutorial, I set up SDL in my project, but when I play it, printf doesnt do anything. #include "SDL.h" #include <stdio.h> int main( int argc, char* args[] ) { printf("Testing"); return 0; } The output looks like this: The program '[4664] SDL Testing.exe: Native' has exited with code 0 (0x0). And that's about it. What could be wrong?

  Read the article

• Workflow Foundation: Asynchronous operations (lengthy network I/O)

  - by StormianRootSolver

  I have to create an application that will be started a few times per day (it's non - interactive). To operate, it needs LARGE amounts of data from the Internet (megabytes) via a rather slow connection, so the WCF service calls take quite some time. At the same time, it needs to perform local calculations and has a sophisticated initialization process. So, what I want to do is to create a workflow that asynchronously fetches the data (takes a few minutes) while already initializing / calculating locally. Is there a way to accomplish this?

  Read the article

• Traversable => Java Iterator

  - by Andres

  I have a Traversable, and I want to make it into a Java Iterator. My problem is that I want everything to be lazily done. If I do .toIterator on the traversable, it eagerly produces the result, copies it into a List, and returns an iterator over the List. I'm sure I'm missing something simple here... Here is a small test case that shows what I mean: class Test extends Traversable[String] { def foreach[U](f : (String) => U) { f("1") f("2") f("3") throw new RuntimeException("Not lazy!") } } val a = new Test val iter = a.toIterator

  Read the article

• Clone a lua state

  - by hbxfnzwpf

  Recently, I have encountered many difficulties when I was developing using C++ and Lua. My situation is: for some reason, there can be thousands of Lua-states in my C++ program. But these states should be same just after initialization. Of course, I can do luaL_loadlibs() and lua_loadfile() for each state, but that is pretty heavy(in fact, it takes a rather long time for me even just initial one state). So, I am wondering the following schema: What about keeping a separate Lua-state(the only state that has to be initialized) which is then cloned for other Lua-states, is that possible?

  Read the article

• BCB: how to get the (approximate) width of a character in a given TFont?

  - by mawg

  It's a TMemo, not that that should make any difference. Googling suggests that I can use Canvas->TextWidth() but those are Delphi examples and BCB doesn't seem to offer this property. I really want something analogous to memo->Font->Height for width. I realize that not all fonts are fixed width, so a good estimate will do. All that I need is to take the width of a TMemo in pixels and make a reasonable guess at how many characters of the current font it will hold. Of course, if I really want to be lazy, I can just google for the average height/width ratio, since height is known. Remember, an approximation is good enough for me if it is tricky to get exact. http://www.plainlanguagenetwork.org/type/utbo211.htm says, " A width to height ratio of 3:5 (0.6) is recommended for most applications"

  Read the article

• emacs/Python: running python-shell in line buffered vs. block buffered mode

  - by Begbie00

  Hi all - In a related question and answer here, someone hypothesized that python-shell within emacs(23.2) was block-buffered instead of line-buffered. The recommended fix was to add sys.stdout.flush() to the spot in my script where I want stdio to flush its contents to the python-shell. Is there someway to trick python-shell (running in emacs 23.2 on Windows, not Linux) into either a) thinking it's attached to a TTY or b) using line-buffered instead of block-buffered mode? I don't see why I'd be able to do this in IDLE but not emacs. I'd rather customize emacs than add sys.stdout.flush() throughout my scripts. Call me lazy :-). Thanks, Mike

  Read the article

• C++ Static Initializer - Is it thread safe

  - by Yan Cheng CHEOK

  Usually, when I try to initialize a static variable class Test2 { public: static vector<string> stringList; private: static bool __init; static bool init() { stringList.push_back("string1"); stringList.push_back("string2"); stringList.push_back("string3"); return true; } }; // Implement vector<string> Test2::stringList; bool Test2::__init = Test2::init(); Is the following code thread safe, during static variable initialization? Is there any better way to static initialize stringlist, instead of using a seperate static function (init)?

  Read the article

• Do we really need a safe release macro?

  - by Ian1971

  Quite a lot of people seem to use a macro such as #define SAFE_RELEASE(X) [X release]; X = nil; (myself included). I've been reassessing why I am using it and wanted to canvas some opinion. The purpose (I think) for using this macro is so that if you were to accidentally use your object after releasing it then you won't get a bad access exception because objective-c will quite happily ignore it when the object is nil. It strikes me that this has the potential to mask some obscure bugs. Maybe it would actually be preferable for the program to crash when you try to use X again. That way during testing you can find the issue and improve the code. Does this macro encourage lazy programming? Thoughts?

  Read the article

• Trick to getting initWithNibFile to be invoked?

  - by PhazeZero

  I've implemented a View Controller, and I'm trying to do some very basic initialization in initWithNibFile...which I understand to be the designated initializer for View Controller objects. I've tried to put breakpoints on the code, and have put very simple NSLog statements into it as well. Regardless...I'm not seeing it be executed (and the object i'm attempting to alloc/init inside the function is also not being allocated - so I'm about 99% sure I'm not hitting the code. Is there something I need to do elsewhere to cause this method to be invoked? I'm getting a clean build, no warnings or errors. And the app successfully loads up the View, and I can invoke a ButtonClick method I've coded and connected to this same View Controller. Any suggestions would be appreciated. TC

  Read the article

• Show surrounding words when searching for a specific word in a text file (Ruby)

  - by Ezra

  Hi, I'm very new to ruby. I'm trying to search for any instance of a word in a text file (not the problem). Then when the word is discovered, it would show the surrounding text (maybe 3-4 words before and after the target word, instead of the whole line), output to a list of instances and continue searching. Example "The quick brown fox jumped over the lazy dog." Search word = "jumped" Output = "...brown fox jumped over the..." Any help is appreciated. Thanks! Ezra def word_exists_in_file f = File.open("test.txt") f.each do line print line if line.match /someword/ return true end end false end

  Read the article

• Controlling the visibility of a Bitmap in .NET

  - by ET

  Hi everyone, I am trying to create this simple application in c#: when the user double clicks on specific location in the form, a little circle will be drawn. By one click, if the current location is marked by a circle - the circle will be removed. I am trying to do this by simply register the MouseDoubleClick and MouseClick events, and to draw the circle from a .bmp file the following way: private void MouseDoubleClick (object sender, MouseEventArgs e) { Graphics g = this.CreateGraphics(); Bitmap myImage = (Bitmap)Bitmap.FromFile("Circle.bmp"); g.DrawImage(myImage, e.X, e.Y); } My problem is that I dont know how to make the circle unvisible when the user clicks its location: I know how to check if the selected location contains a circle (by managing a list of all the locations containig circles...), but I dont know how exactly to delete it. Another question: should I call the method this.CreateGraphics() everytime the user double-clicks a location, as I wrote in my code snippet, or should I call it once on initialization?

  Read the article

• Best practice for passing configuration to each GUI object

  - by Laimoncijus

  Hi, I am writing an application, where I do have few different windows implemented, where each window is a separate class. Now I need somehow to pass a single configuration object to all of them. My GUI is designed in way, where I have one main window, which may create some child windows of its own, and these child windows can have their own childs (so there is no possibility to create all windows in initialization part and feed the config object to all of them from the very beginning)... What would be best practice for sharing this configuration object between them? Always passing via constructor or maybe making it somewhere as final public static and let each window object to access it when needed? Thanks

  Read the article

• C++, create an instance from a static method

  - by Manux

  Hello, let's say I want my users to use only one class, say SpecialData. Now, this data class would have many methods, and depending on the type of data, the methods do different things, internally, but return externally similar results. Therefore my wanting to have one "public" class and other "private", child classes that would change the behavior of methods, etc... It would be amazingly more simple for some types of data that need to be built to do something like this: SpecialData& sm = SpecialData::new_supermatrix(); and new_supermatrix() would return a SuperMatrix instance, which inherits from most behaviors of SpecialData. my header: static SpecialData& new_supermatrix(); my cpp: SpecialData& SpecialData::new_supermatrix()(){ return SuperMatrix(MATRIX_DEFAULT_MAGNITUDE,1000,1239,FLOAT32,etc...); } The problem is, I get this error, which is probably logical due to the circumstances: invalid initialization of non-const reference of type ‘SpecialData&’ from a temporary of type ‘SpecialData’ So, any ideas?

  Read the article

• Cannot use String.Empty as a default value for an optional parameter in C# - then what's the point?

  - by Mikeyg36

  I am reading Effective C# by Bill Wagner. In Item 14 - Minimize Duplicate Initialization Logic, he shows the following example of using the new optional parameters feature in a constructor: public MyClass(int initialCount = 0, string name = "") Notice that he used "" instead of string.Empty. He comments: You'll note [in an example above] that the second constructor specified "" for the default value on the name parameter, rather than the more customary string.Empty. That's because string.Empty is not a compile-time constant. It is a static property defined in the string class. Because it is not a compile constant, you cannot use it for the default value for a parameter. If we cannot use the string.Empty static in all situations, then doesn't that defeat the purpose of it? I thought that we would use it to be sure that we have a system-independent means of referring to the empty string. Is my understanding wrong? Thanks.

  Read the article

• Segmentation fault problem (C)

  - by user228938

  I have a struct named Game with an array of levels, defined like this: typedef struct { Level levels[x]; } Game; When I compile the code, if x is 1, 2 or 3, the program runs normally. If it's any other value (4, for instance), I get a segmentation fault. I'm not accessing the array anywhere. Main is something like this at the moment (commented everything except the initialization): int main (...) { Game g; return 0; } Any clue of what this might be? Thanks in advance.

  Read the article

• Java Architecture Decision !!

  - by santiagobasulto

  Hi everybody! I'm developing a medium Java app, and i'm facing a small problem due to my lack of expirience. I've a custom DAO, which gets "Article" objects from the DataBase. I've the Article class, and the DAO has a method called getArticle(int id), this method returns an Article. The Article has a Category object, and i'm using lazy loading. So, when i request for an Article Category (Article a = new Article(); a.getCategory();) the Article class gets the Category from the DAO and then returns it. I'm now thinking to cache it, so when i request multiple times to an Article's category, the database is only queried one time. My question is: where should i put that cache? I can put it on the Article class (in the DTO), or i can put it on the DAO class. What do you say? Thanks!

  Read the article

• Simplest one-to-many Map case in Hibernate doesn't work in MySQL

  - by Malvolio

  I think this is pretty much the simplest case for mapping a Map (that is, an associative array) of entities. @Entity @AccessType("field") class Member { @Id protected long id; @OneToMany(cascade = CascadeType.ALL, fetch=FetchType.LAZY) @MapKey(name = "name") private Map<String, Preferences> preferences = new HashMap<String, Preferences>(); } @Entity @AccessType("field") class Preferences { @ManyToOne Member member; @Column String name; @Column String value; } This looks like it should work, and it does, in HSQL. In MySQL, there are two problems: First, it insists that there be a table called Members_Preferences, as if this were a many-to-many relationship. Second, it just doesn't work: since it never populates Members_Preferences, it never retrieves the Preferences. [My theory is, since I only use HSQL in memory-mode, it automatically creates Members_Preferences and never really has to retrieve the preferences map. In any case, either Hibernate has a huge bug in it or I'm doing something wrong.]

  Read the article

• java cannot reserver heap size error on windows server

  - by Prad

  HI, I have the following configuration: Server : windows 2003 server (32 bit) java version: 1.5_0_22 I get the following error when executing from command line ( my code is based off eclipse wihch gives the same error) java -XX:MaxPermSize=256m -Xmx512m Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. The server has over 20GB physical memory with over 19 GB free right now. It does not give an error upto -Xmx486m I have read other articles about contiguous memory space. There is hardly anything running on this server. Can I validae this in any way? Thanks

  Read the article

• GetWindowLongPtr fails if called when handling WM_CREATE

  - by Semen Semenych

  Calling the GetWindowLongPtr function for a dialog box with the DWL_USER parameter fails when done from the WM_CREATE handler. It gives no error (checked that, the return value is always zero), which, according to the MSDN documentation, occurs only if SetWindowLongPtr has not been called previously. However, I call it after registering the window class, and properly call the SetWindowPos after that. Finally, calling GetWindowLongPtr in any other event handler, that is, later than WM_CREATE, works fine. Is there something I'm missing in the initialization sequence, or maybe the messages are sent in some not so obvious order?

  Read the article

• Caching stored procedure results in Linq'u

  - by itdebeloper

  In our web application we have a lots of stored procedures look like this one: getSomeData(/* 7 diffrent params */) This stored procedure don't make any updates. We are using Linq'u. I know that the date are changing no often than once per day so the results for the same sets of parameters values will be the same. Does Linqu have cache simple solution? I know how to 'manually' write cache mechanism in .net, but I supposed that in Linqu this problem was solved. I'm a lazy guy :) so I'm looking for something realy simple like: Linqu_global_store_procedure_configuration.CacheDuration="600" Linqu_global_store_procedure_configuration.CacheVaryByParam="*" I'm using .net 3.5 but its not any problem to move for 4.0.

  Read the article

• In which layer should I join 2 entities together?

  - by William

  I use Spring MVC and a regular JDBC. I've just learned that I should separate business process into layers which are presentation layer, controller layer, service layer, and repository/DAO layer. Now suppose that I have an Entity called Person that can have multiple Jobs. Job itself is another entity which have its own properties. From what I gathered, the repository layer only manages one entity. Now I have one entity that contains another entity. Where do I "join" them? The service layer? Suppose I want to get a person whose job isn't known yet (lazy loading). But the system might ask what the job of that particular person is later on. What is the role of each layer in this case? Please let me know if I need to add any detail into this question.

  Read the article

• Not loading the object caused EF4 (code first) to remove the relationship

  - by Lavinski

  Firstly this is a EF4: Code First - Property Loading question. I'm loading an object like so var item = Context.Table.Find( update.Identifier ); This object has a property Relationship so a table has a Relationship object. Now i'm updating my item but my Relationship object is not toched (and therefore not lazy loaded). Now here's the problem .. I save my item and my relationship to the Relationship object is deleted, apparently the model thinks i set it to null. However it all works if I look at the property before saving. So I'm looking into LoadProperty or doing a query and using Include. Has anyone else come across this issue and how did you get around it?

  Read the article

• Howto check if a object is connected to another in hibernate

  - by codevourer

  Imagine two domain object classes, A and B. A has a bidirectional one-to-many relationship to B. A is related to thousands of B. The relations must be unique, it's not possible to have a duplicate. To check if an instance of B is already connected to a given instance of A, we could perform an easy INNER JOIN but this will only ensure the already persisted relations. What about the current transient relations? class A { @OneToMany private List<B> listOfB; } If we access the listOfB and perform a check of contains() this will fetch all the connected instances of B lazy from the datasource. I only want to validate them by their primary-key. Is there an easy solution where I can do things like "Does this instance of A is connected with this instance of B?" Without loading all these data into memory and perform a based on collections?

  Read the article

• Initializing and accessing a pointer from an array of pointers

  - by idealistikz

  Suppose I have the following: void **Init(int numElems) { //What is the best way to intialize 'ptrElems' to store an array of void *'s? void **ptrElems = malloc(numElems * sizeof(void *)); return ptrElems; } //What is the best way to return a pointer pointing at the index passed as a parameter? void **GetPtr(void **ptrElems, int index) { void **elem = elems + (index * sizeof(void *)); return elem; } First, what is the best way to intialize 'ptrElems' to store an array of pointers? I use malloc because assigning it to an array will not persist after the end of the function. Second, what is the best way to point to the pointer at the specified index? I tried typecasting the first line of the 'GetPtr' function to ensure proper pointer arithmetic, but I receive the warning, 'initialization from incompatible pointer type'. Is it necessary to typecast?

  Read the article

< Previous Page | 63 64 65 66 67 68 69 70 71 72 73 74  | Next Page >