Search Results

Search found 28744 results on 1150 pages for 'higher order functions'.

Page 413/1150 | < Previous Page | 409 410 411 412 413 414 415 416 417 418 419 420  | Next Page >

  • event vs thread programming on server side.

    - by AlxPeter
    We are planning to start a fairly complex web-portal which is expected to attract good local traffic and I've been told by my boss to consider/analyse node.js for the serve side. I think scalability and multi-core support can be handled with an Nginx or Cherokee up in the front. 1) Is this node.js ready for some serious/big business? 2) Does this 'event/asynchronous' paradigm on server side has the potential to support the heavy traffic and data operation ? considering the fact that 'everything' is being processed in a single thread and all the live connections would be lost if it got crashed (though its easy to restart). 3) What are the advantages of event based programming compared to thread based style ? or vice-versa. (I know of higher cost associated with thread switching but hardware can be squeezed with event model.) Following are interesting but contradicting (to some extent) papers:- 1) http://www.usenix.org/events/hotos03/tech/full_papers/vonbehren/vonbehren_html 2) http://pdos.csail.mit.edu/~rtm/papers/dabek:event.pdf

    Read the article

  • C++ Thread level constants

    - by Gokul
    Is there a way by which we can simulate thread level constants in C++? For example, if i have to make a call to template functions, then i need to mention the constants as template level parameters? I can use static const variables for template metaprogramming, but they are process level constants. I know, i am asking a question with a high probability of 'No'. Just thought of asking this to capitalize on the very rare probability :)) Thanks, Gokul.

    Read the article

  • Why so many individual System.Web.* DLLs?

    - by toasteroven
    I've been thinking about ways to refactor a fairly expansive class/utility library I have, and one thing I think I want to do is split off any higher-level helper utilities that introduce new dependencies. I read some previous questions here, and one that I particularly noticed was a comment about how Microsoft freely uses namespaces across DLLs. The example given was System.Web - it's in the base framework, but there's also a System.Web.dll that adds more functionality to the namespace if you want it. I also noticed several other System.Web.* DLLs available, and I was wondering if there's a reason why they wouldn't be combined into a single DLL. Could it be that they have their own individual dependencies and Microsoft (like me) wanted to separate assemblies along those lines? Or is it for easier maintenance? Something else entirely?

    Read the article

  • data ownership and performance

    - by Ami
    We're designing a new application and we ran into some architectural question when thinking about data ownership. we broke down the system into components, for example Customer and Order. each of this component/module is responsible for a specific business domain, i.e. Customer deals with CRUD of customers and business process centered around customers (Register a n new customer, block customer account, etc.). each module is the owner of a set of database tables, and only that module may access them. if another module needs data that is owned by another module, it retrieves it by requesting it from that module. so far so good, the question is how to deal with scenarios such as a report that needs to show all the customers and for each customer all his orders? in such a case we need to get all the customers from the Customer module, iterate over them and for each one get all the data from the Order module. performance won't be good...obviously it would be much better to have a stored proc join customers table and orders table, but that would also mean direct access to the data that is owned by another module, creating coupling and dependencies that we wish to avoid. this is a simplified example, we're dealing with an enterprise application with a lot of business entities and relationships, and my goal is to keep it clean and as loosely coupled as possible. I foresee in the future many changes to the data scheme, and possibly splitting the system into several completely separate systems. I wish to have a design that would allow this to be done in a relatively easy way. Thanks!

    Read the article

  • File Operations in Android NDK

    - by EnderX
    I am using the Android NDK to make an application primarily in C for performance reasons, but it appears that file operations such as fopen do not work correctly in Android. Whenever I try to use these functions, the application crashes. How do I create/write to a file with the Android NDK?

    Read the article

  • .NET - Unable to get values from Value property of HtmlInputHidden

    - by user245123
    I have a custom control that inherits from .NET's CompositeControl class. This control overrides the CreateChildControls in order to build its child controls dynamically. I need the page to post back after a couple different javascript events occur on the client side. In order to accomplish this, I create two hidden controls on the page so I can set their values with javascript, submit the page, and read the values out on server side. Here's is the code I use to create these two hiddens: Protected Overrides Sub CreateChildControls() hdEventName = New HiddenField() Controls.Add(hdEventName) hdEventName.ID = "hdEventName" hdEventArgs = New HiddenField() Controls.Add(hdEventArgs) hdEventArgs.ID = "hdEventValue" ' other controls ' ... End Sub When a javascript event occurs I set the value attribute of the two hiddens and submit the page, like so: hdEventName.value = 'EventName'; hdEventArgs.value = 'arg1,arg2'; document.forms[0].submit(); In the OnLoad method of my control, I attempt to check the Value property of the hdEventName and hdEventArgs controls, but it is always empty. However, Page.Request.Form(hdEventName.UniqueID) and Page.Request.Form(hdEventArgs.UniqueID) return correct values. The actual HTML in the markup also shows correct values after the page posts back. Why is the Value property of the HtmlInputHiddens disconnected from the actual value that appears on the client?

    Read the article

  • Reading bytes from JavaScript string

    - by Jan
    I have a string containing binary data in JS. Now I want to read, for example, an integer from it. So I get the first 4 characters, use charCodeAt, do some shifting etc. to get an integer. Problem is that strings in JS are UTF-16 (instead of ASCII) and charCodeAt often returns values higher than 256. The Mozilla reference states that "The first 128 Unicode code points are a direct match of the ASCII character encoding." (what about ASCII values 128?) How can I convert the result of charCodeAt to an ASCII value? Or is there a better way to convert a string of four characters to a 4 byte integer?

    Read the article

  • iPhone + OpenGL + Touches: FPS drop

    - by Anton
    Hey there, Recently I ran into a very strange issue: touching the screen of the iPhone and moving a finger around can eat up to 50% of my FPS. Yeah, I checked my code for possible bottlenecks – not the issue. The last resort I tried before writing this post – commenting out all the touch processing code and looking at FPS then. Results are: no touches – 58-60. Touching and moving the finger – 35-40 FPS instantly. The rendering is done in a separate thread, so that no main runloop events shall collide with it. However, it's very crushial for me (and the game I develop) to resolve this issue, because such FPS drop is really noticeable. Thank you for your help in advance. UPDATE: seems that setting rendering thread's priority to higher value helps a bit...

    Read the article

  • Help a newbie with a PHP Function

    - by danit
    I want to use this function: http://www.frankmacdonald.co.uk/php/post-to-wordpress-with-php.html Its used to post to Wordpress using XMLRPC, can anyone give me the basics for using this function and maybe a brief over view? I want to learn how functions work and how to use them.

    Read the article

  • getJSON and variable scope in javascript

    - by nillls
    Hi! In order to make function calls to our back-end php code we've implemented something called an ActionProxy like this: function ActionProxy(action, input, callback){ $.post("ActionProxy.php?method="+action, { data: input}, function(data, textStatus, XMLHttpRequest){ //return data.ResponseWhatever } }); The problem we're having is that using data outside the ActionProxy is impossible due to variable scope limitations (we assume), setting var res = data.ResponseWhatever or return data.ResponseWhatever is pretty futile. How would one handle these responses most appropriately so that functions calling the actionproxy can access the response values?

    Read the article

  • Database schema to store AND, OR relation, association

    - by user455387
    Many thanks for your help on this. In order for an entreprise to get a call for tender it must meet certain requirements. For the first example the enterprise must have a minimal class 4, and have qualification 2 in sector 5. Minimal class is always one number. Qualification can be anything (single, or multiple using AND, OR logical operators) I have created tables in order to map each number to it's given name. Now I need to store requirements in the database. minimal class 4 Sector Qualification 5.2 minimal class 2 Sector Qualifications 3.9 and 3.10 minimal class 3 Sector Qualifications 6.1 or 6.3 minimal class 1 Sector Qualifications (3.1 and 3.2) or 5.6 class Domain < ActiveRecord::Base has_many :domain_classes has_many :domain_sectors has_many :sector_qualifications, :through => :domain_sectors end class DomainClass < ActiveRecord::Base belongs_to :domain end class DomainSector < ActiveRecord::Base belongs_to :domain has_many :sector_qualifications end class SectorQualification < ActiveRecord::Base belongs_to :domain_sector end create_table "domains", :force => true do |t| t.string "name" end create_table "domain_classes", :force => true do |t| t.integer "number" t.integer "domain_id" end create_table "domain_sectors", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_id" end create_table "sector_qualifications", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_sector_id" end

    Read the article

  • VB.NET Function Return

    - by waves
    In order to return a value from a VB.NET function one can assign a value to the "Functions Name" or use "return value." I sometimes see these inter-mixed in the same function. Personally, I prefer the return. My question is, what is the internal difference, if any, between the two?

    Read the article

  • Access message inbox without Content UrI (content//:sms)

    - by Nishant Kumar
    Hi, I want to access the messages stored in inbox through my android project. I have tried the method of forming URI for sms (content://sms/ inbox) and then quering it for various parametres. But I cannot find any documentation for reading inbox sms in the standard Android Developr Docs. It was mentioned at various websites that this content has been removed from the standard sdk. The application may not support higher version of android. So, how can I create an apllication to read sms from inbox that is reliable in furture version of android. Please help !!

    Read the article

  • Datastructure choices for highspeed and memory efficient detection of duplicate of strings

    - by Jonathan Holland
    I have a interesting problem that could be solved in a number of ways: I have a function that takes in a string. If this function has never seen this string before, it needs to perform some processing. If the function has seen the string before, it needs to skip processing. After a specified amount of time, the function should accept duplicate strings. This function may be called thousands of time per second, and the string data may be very large. This is a highly abstracted explanation of the real application, just trying to get down to the core concept for the purpose of the question. The function will need to store state in order to detect duplicates. It also will need to store an associated timestamp in order to expire duplicates. It does NOT need to store the strings, a unique hash of the string would be fine, providing there is no false positives due to collisions (Use a perfect hash?), and the hash function was performant enough. The naive implementation would be simply (in C#): Dictionary<String,DateTime> though in the interest of lowering memory footprint and potentially increasing performance I'm evaluating a custom data structures to handle this instead of a basic hashtable. So, given these constraints, what would you use? EDIT, some additional information that might change proposed implementations: 99% of the strings will not be duplicates. Almost all of the duplicates will arrive back to back, or nearly sequentially. In the real world, the function will be called from multiple worker threads, so state management will need to be synchronized.

    Read the article

  • How can I manually uninstall .NET Framework Beta 2?

    - by DannyAsher
    Uninstalled VS2010 Beta 2. Uninstalled .NET Framework 4 Extended Beta 2. On attempting to uninstall .NET Framework 4 Client Profile Beta 2. I get Blocking Issues: You must uninstall the .NET Framework 4 Extended Beta 2 before you uninstall the .NET Framework 4 Client Profile Beta 2. On attempting to reinstall Framework 4 Beta 2 I get: Details: Same or higher version of .NET Framework 4 Beta 2 has already been installed on this computer. Please help! Can I simply remove registry entries and the C:\WINDOWS\Microsoft.NET\Framework\v4.0.21006 directory?

    Read the article

  • What happens if I just add a second IP to a domain?

    - by tntu
    We have two servers that are in constant sync. We have two applications that connect to them. Each app to different server. We devised a new version of those apps that will read a dns entry and get a list of IP addresses and try them in order. Now problem is old apps. We have noticed that some ppl still use the old ones even if we have released the new. If we were to add two IP's to each domain would they receive the IP's in the order we set them or random? Either way it will still work for us but I'm just curious. If first server goes offline will the client application try the other? To be noted for old version: Interruption does not affect in any way the continuation once connection is reestablished. Each communication is independent of previous ones. Applications connect at set intervals of time anywhere between 5 seconds to 1 hour. Connection is done simply using an http post to the URL in question.

    Read the article

  • How do I generate optimized SQL with my (added) partial methods on LINQ entities

    - by Ra
    Let's say I have a Person table with a FirstName and LastName column. I extended the Person LINQ entity class with a get property "FullName", that concatenates the first and last names. A LINQ query like: from person... select fullName where id = x generates SQL selecting all Patient columns, since FullName is evaluated after firing the query. I would like to limit the select clause to only the 2 columns required. This is a simple example, but the limitation it shows is that I cannot isolate my business/formatting rules but have to embed them in the LINQ query, so they're not reusable (since it is in the select part) or I need select both columns separately, and then concatenate them higher up in the data or business layer with static helper methods. Any ideas for a clean design using the entity partial classes or extensions? Thanks

    Read the article

  • Question with "extern" in C

    - by why
    When programming, I would like to split one large file(which contains main function) to many small files, so there is one common case: functions in small files can modify the var from main file, so i think extern is very useful! for instance: in main.c extern int i = 100; in small.c extern int i; fprintf(stdout, "var from main file: %d\n", i); I just want to know is my understanding right?

    Read the article

  • Set global position for a QLabel

    - by alfredozn
    Hi I'm trying to display a QLabel (without parent) at a fixed position using PyQt. The QLabel functions as a graphic that appears only for a moment, it's appears in the middle of the screen by default but I can't find how to move its position. Any suggestion??

    Read the article

  • $_POST Variable Detected in Chrome but not in Firefox

    - by user1707973
    I am using 2 images in a form to sort out query results from the database. The form is submitted using the POST method. When i click on the first image, the query results have to be sorted in ascending order, and when i click on the second, the results have to be sorted in the descending order. This is the code for the form: <form name="" action="" method="post"> <input type="hidden" name="typep" value="price" /> <input type="image" name="sort" value="asc" src="images/asc-ar.png" /> <input type="image" name="sort" value="desc" src="images/dsc-ar.png" /> </form> Now this is the code for checking if the $_REQUEST['sort'] variable is set and therefore whether sorting is required or not. if ($_REQUEST['sort'] != "") { $sort = $_REQUEST['sort']; $typep = $_REQUEST['typep']; //query to be executed depending on values of $sort and $typep } Firefox does detect the $_REQUEST['typep'] variable but not the $_REQUEST['sort'] one. This works perfectly in Chrome though. When i test the site in Firefox, it doesn't detect the $_REQUEST['sort'] variable and therefore the if condition evaluates to false and the search results don't get sorted.

    Read the article

  • NHibernate and MySql Keywords

    - by jalchr
    Why Nibernate HQL can not handle the following query: from Deal D where (D.ApprovalDate + INTERVAL 1 Year) < current_timestamp() < (D.RenewalDate + INTERVAL -1 Year) knowing that INTERVAL and YEAR are keywords in MySQL, so this is kind of mixing Sql within Hql (unless Hql can handle date functions like so and I don't know) . The dialect is MySQLDialect Its perfectly valid to execute this query SELECT '2005-01-01' + INTERVAL 1 Year;

    Read the article

  • MySQL: optimization of table (indexing, foreign key) with no primary keys

    - by Haradzieniec
    Each member has 0 or more orders. Each order contains at least 1 item. memberid - varchar, not integer - that's OK (please do not mention that's not very good, I can't change it). So, thera 3 tables: members, orders and order_items. Orders and order_items are below: CREATE TABLE `orders` ( `orderid` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT, `memberid` VARCHAR( 20 ), `Time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP , `info` VARCHAR( 3200 ) NULL , PRIMARY KEY (orderid) , FOREIGN KEY (memberid) REFERENCES members(memberid) ) ENGINE = InnoDB; CREATE TABLE `order_items` ( `orderid` INT(11) UNSIGNED NOT NULL, `item_number_in_cart` tinyint(1) NOT NULL , --- 5 items in cart= 5 rows `price` DECIMAL (6,2) NOT NULL, FOREIGN KEY (orderid) REFERENCES orders(orderid) ) ENGINE = InnoDB; So, order_items table looks like: orderid - item_number_in_cart - price: ... 1000456 - 1 - 24.99 1000456 - 2 - 39.99 1000456 - 3 - 4.99 1000456 - 4 - 17.97 1000457 - 1 - 20.00 1000458 - 1 - 99.99 1000459 - 1 - 2.99 1000459 - 2 - 69.99 1000460 - 1 - 4.99 ... As you see, order_items table has no primary keys (and I think there is no sense to create an auto_increment id for this table, because once we want to extract data, we always extract it as WHERE orderid='1000456' order by item_number_in_card asc - the whole block, id woudn't be helpful in queries). Once data is inserted into order_items, it's not UPDATEd, just SELECTed. The questions are: I think it's a good idea to put index on item_number_in_cart. Could anybody please confirm that? Is there anything else I have to do with order_items to increase the performance, or that looks pretty good? I could miss something because I'm a newbie. Thank you in advance.

    Read the article

  • In jQuery, is there any way to only bind a click once?

    - by Chris Henry
    I have an ajax app that will run functions on every interaction. I'd like to be able to run my setup function each time so all my setup code for that function remains encapsulated. However, binding elements more than once means that the handler will run more than once, which is obviously undesirable. Is there an elegant way in jQuery to call bind on an element more than once without the handler being called more than once?

    Read the article

< Previous Page | 409 410 411 412 413 414 415 416 417 418 419 420  | Next Page >