Search Results

Search found 13151 results on 527 pages for 'performance counters'.

Page 456/527 | < Previous Page | 452 453 454 455 456 457 458 459 460 461 462 463  | Next Page >

  • Did I find a bug in WriteableBitmap when using string literals

    - by liserdarts
    For performance reasons I'm converting a large list of images into a single image. This code does exactly what I want. Private Function FlattenControl(Control As UIElement) As Image Control.Measure(New Size(1000, 1000)) Control.Arrange(New Rect(0, 0, 1000, 1000)) Dim ImgSource As New Imaging.WriteableBitmap(1000, 1000) ImgSource.Render(Control, New TranslateTransform) ImgSource.Invalidate Dim Img As New Image Img.Source = ImgSource Return Img End Function I can add all the images into a canvas pass the canvas to this function and I get back one image. My code to load all the images looks like this. Public Function BuildTextures(Layer As GLEED2D.Layer) As FrameworkElement Dim Container As New Canvas For Each Item In Layer.Items If TypeOf Item Is GLEED2D.TextureItem Then Dim Texture = CType(Item, GLEED2D.TextureItem) Dim Url As New Uri(Texture.texture_filename, UriKind.Relative) Dim Img As New Image Img.Source = New Imaging.BitmapImage(Url) Container.Children.Add(Img) End If Next Return FlattenControl(Container) End Function The GLEED2D.Layer and GLEED2D.TextureItem classes are from the free level editor GLEED2D (http://www.gleed2d.de/). The texture_filename on every TextureItem is "Images/tree_clipart_pine_tree.png" This works just fine, but it's just a proof of concept. What I really need to do (among other things) is have the path to the image hard coded. If I replace Texture.texture_filename in the code above with the string literal "Images/tree_clipart_pine_tree.png" the images do not appear in the final merged image. I can add a breakpoint and see that the WriteableBitmap has all of it's pixels as 0 after the call to Invalidate. I have no idea how this could cause any sort of difference, but it gets stranger. If I remove the call to FlattenControl and just return the Canvas instead, the images are visible. It's only when I use the string literal with the WriableBitmap that the images do not appear. I promise you that the value in the texture_filename property is exactly "Images/tree_clipart_pine_tree.png". I'm using Silverlight 3 and I've also reproduced this in Silverlight 4. Any ideas?

    Read the article

  • Large number of simultaneous long-running operations in Qt

    - by Hostile Fork
    I have some long-running operations that number in the hundreds. At the moment they are each on their own thread. My main goal in using threads is not to speed these operations up. The more important thing in this case is that they appear to run simultaneously. I'm aware of cooperative multitasking and fibers. However, I'm trying to avoid anything that would require touching the code in the operations, e.g. peppering them with things like yieldToScheduler(). I also don't want to prescribe that these routines be stylized to be coded to emit queues of bite-sized task items...I want to treat them as black boxes. For the moment I can live with these downsides: Maximum # of threads tend to be O(1000) Cost per thread is O(1MB) To address the bad cache performance due to context-switches, I did have the idea of a timer which would juggle the priorities such that only idealThreadCount() threads were ever at Normal priority, with all the rest set to Idle. This would let me widen the timeslices, which would mean fewer context switches and still be okay for my purposes. Question #1: Is that a good idea at all? One certain downside is it won't work on Linux (docs say no QThread::setPriority() there). Question #2: Any other ideas or approaches? Is QtConcurrent thinking about this scenario? (Some related reading: how-many-threads-does-it-take-to-make-them-a-bad-choice, many-threads-or-as-few-threads-as-possible, maximum-number-of-threads-per-process-in-linux)

    Read the article

  • Regex to extract this semi formatted data

    - by Codygman
    Alright, I can't quite figure out how to do this. Given the following text: Roland AX-1: /start Roland's AX-1 strap-on remote MIDI controller has a very impressive 45-note velocity sensitive keyboard, and has switchable velocity curves, goes octave up/down, transpose, split/layering zones, and has fun tempo control for sequencers and more. Roland's AX-1 comes with a built-in GS control for total MIDI control of GM/GS synths. Its "Expression Bar" can control pitch and mod via an almost ribbon-like controller. It's also the newest and most advanced remote controller for your synths or midi modules. /end Roland AX-7: /start Roland's AX-7 builds on the infamous Roland AX-1 design. You just strap it on and put it to the front of the stage. Offering several controllers, such as: a D-Beam, then you can open the door to amazing live performance. 7-segment LED display, larger patch memory (Around 128 patches with MIDI data backup), and comes with GM2/GS compatibility make it extra easy to use. The 45-note, velocity-sensitive keyboard. 5 realtime controllers including a data entry knob, touch controller knob, opression bar, a hold button, and D-Beam. 128 patches with MIDI data backup. 2 MIDI zones. /end I'm trying to use the following: /^([\w\d \-]*):\s\s\s\s^\/start([^\:]*)\/end$/im You can see on rubular here: http://rubular.com/r/BVRRHsnWdp Thanks for any help. I guess i'm trying to match blocks of text until I hit the next title which always ends with a :$

    Read the article

  • Scope of Connection Object for a Website using Connection Pooling (Local or Instance)

    - by Danny
    For a web application with connection polling enabled, is it better to work with a locally scoped connection object or instance scoped connection object. I know there is probably not a big performance improvement between the two (because of the pooling) but would you say that one follows a better pattern than the other. Thanks ;) public class MyServlet extends HttpServlet { DataSource ds; public void init() throws ServletException { ds = (DataSource) getServletContext().getAttribute("DBCPool"); } protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { SomeWork("SELECT * FROM A"); SomeWork("SELECT * FROM B"); } void SomeWork(String sql) { Connection conn = null; try { conn = ds.getConnection(); // execute some sql ..... } finally { if(conn != null) { conn.close(); // return to pool } } } } Or public class MyServlet extends HttpServlet { DataSource ds; Connection conn;* public void init() throws ServletException { ds = (DataSource) getServletContext().getAttribute("DBCPool"); } protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { try { conn = ds.getConnection(); SomeWork("SELECT * FROM A"); SomeWork("SELECT * FROM B"); } finally { if(conn != null) { conn.close(); // return to pool } } } void SomeWork(String sql) { // execute some sql ..... } }

    Read the article

  • Is there any better IDOMImplementation other than MSXML?

    - by Chau Chee Yang
    There are 3 IDOMImplementation available in Delphi: MSXML Xerces XML ADOM XML v4 MSXML is the default IDOMImplementation. My test is count the time need to load a 10MB xml file. I use a Delphi unit generated from a XSD using XML data binding to load the xml file. This unit has 3 common function: function Getmenubar(Doc: IXMLDocument): IXMLMenubarType; function Loadmenubar(const FileName: WideString): IXMLMenubarType; function Newmenubar: IXMLMenubarType; I learn from the web that some comment that MSXML's overhead is high that it doesn't perform if compare to other XML parser. However, my study shows that MSXML is the best among others. Xerces XML 2nd and ADOM XML v4 the worst: MSXML - 0.6410 seconds Xerces XML - 2.4220 seconds ADOM XML v4 - 67.50 seconds I also come across with OmniXML that claim to have much better performance compare to MSXML but I never success using it with the unit generated by XML data binding. Is there any other vendor that implement IDOMImplementation of Delphi that work much better than MSXML? I am using Delphi 2010 and Windows 7.

    Read the article

  • Could CouchDB benefit significantly from the use of BERT instead of JSON?

    - by Victor Rodrigues
    I appreciate a lot CouchDB attempt to use universal web formats in everything it does: RESTFUL HTTP methods in every interaction, JSON objects, javascript code to customize database and documents. CouchDB seems to scale pretty well, but the individual cost to make a request usually makes 'relational' people afraid of. Many small business applications should deal with only one machine and that's all. In this case the scalability talk doesn't say too much, we need more performance per request, or people will not use it. BERT (Binary ERlang Term http://bert-rpc.org/ ) has proven to be a faster and lighter format than JSON and it is native for Erlang, the language in which CouchDB is written. Could we benefit from that, using BERT documents instead of JSON ones? I'm not saying just for retrieving in views, but for everything CouchDB does, including syncing. And, as a consequence of it, use Erlang functions instead of javascript ones. This would modify some original CouchDB principles, because today it is very web oriented. Considering I imagine few people would make their database API public and usually its data is accessed by the users through an application, it would be a good deal to have the ability to configure CouchDB for working faster. HTTP+JSON calls could still be handled by CouchDB, considering an extra cost in these cases because of parsing.

    Read the article

  • DDD: Aggregate Roots

    - by Mosh
    Hello, I need help with finding my aggregate root and boundary. I have 3 Entities: Plan, PlannedRole and PlannedTraining. Each Plan can include many PlannedRoles and PlannedTrainings. Solution 1: At first I thought Plan is the aggregate root because PlannedRole and PlannedTraining do not make sense out of the context of a Plan. They are always within a plan. Also, we have a business rule that says each Plan can have a maximum of 3 PlannedRoles and 5 PlannedTrainings. So I thought by nominating the Plan as the aggregate root, I can enforce this invariant. However, we have a Search page where the user searches for Plans. The results shows a few properties of the Plan itself (and none of its PlannedRoles or PlannedTrainings). I thought if I have to load the entire aggregate, it would have a lot of overhead. There are nearly 3000 plans and each may have a few children. Loading all these objects together and then ignoring PlannedRoles and PlannedTrainings in the search page doesn't make sense to me. Solution 2: I just realized the user wants 2 more search pages where they can search for Planned Roles or Planned Trainings. That made me realize they are trying to access these objects independently and "out of" the context of Plan. So I thought I was wrong about my initial design and that is how I came up with this solution. So, I thought to have 3 aggregates here, 1 for each Entity. This approach enables me to search for each Entity independently and also resolves the performance issue in solution 1. However, using this approach I cannot enforce the invariant I mentioned earlier. There is also another invariant that states a Plan can be changed only if it is of a certain status. So, I shouldn't be able to add any PlannedRoles or PlannedTrainings to a Plan that is not in that status. Again, I can't enforce this invariant with the second approach. Any advice would be greatly appreciated. Cheers, Mosh

    Read the article

  • AutoMapper How To Map Object A To Object B Differently Depending On Context

    - by IanT8
    Calling all AutoMapper gurus! I'd like to be able to map object A to object B differently depending on context at runtime. In particular, I'd like to ignore certain properties in one mapping case, and have all properties mapped in another case. What I'm experiencing is that Mapper.CreateMap can be called successfully in the different mapping cases however, once CreateMap is called, the map for a particular pair of types is set and is not subsequently changed by succeeding CreateMap calls which might describe the mapping differently. I found a blog post which advocates Mapper.Reset() to get round the problem, however, the static nature of the Mapper class means that it is only a matter of time before a collision and crash occur. Is there a way to do this? What I think I need is to call Mapper.CreateMap once per appdomain, and later, be able to call Mapper.Map with hints about which properties should be included / excluded. Right now, I'm thinking about changing the source code by writing a non-static mapping class that holds the mapping config instance based. Poor performance, but thread safe. What are my options. What can be done? Automapper seems so promising.

    Read the article

  • Static method , Abstract method , Interface method comparision ?

    - by programmerist
    When i choose these methods? i can not decide which one i must prefer or when will i use one of them?which one give best performance? First Type Usage public abstract class _AccessorForSQL { public virtual bool Save(string sp, ListDictionary ld, CommandType cmdType); public virtual bool Update(); public virtual bool Delete(); public virtual DataSet Select(); } class GenAccessor : _AccessorForSQL { DataSet ds; DataTable dt; public override bool Save(string sp, ListDictionary ld, CommandType cmdType) { } public override bool Update() { return true; } public override bool Delete() { return true; } public override DataSet Select() { DataSet dst = new DataSet(); return dst; } Second Type Usage Also i can write it below codes: public class GenAccessor { public Static bool Save() { } public Static bool Update() { } public Static bool Delete() { } } Third Type Usage Also i can write it below codes: public interface IAccessorForSQL { bool Delete(); bool Save(string sp, ListDictionary ld, CommandType cmdType); DataSet Select(); bool Update(); } public class _AccessorForSQL : IAccessorForSQL { private DataSet ds; private DataTable dt; public virtual bool Save(string sp, ListDictionary ld, CommandType cmdType) { } } } I can use first one below usage: GenAccessor gen = New GenAccessor(); gen.Save(); I can use second one below usage: GenAccessor.Save(); Which one do you prefer? When will i use them? which time i need override method ? which time i need static method?

    Read the article

  • Java EE suitablity for a social network using Cassandra datastore ??

    - by Marcos
    We are in the process of making some important technology decisions for a social networking application. We're planning to have Cassandra(a NoSQL database to support efficient data storage). We would be using Hector(a Java client) to interact with Cassandra. 1.) Would Java EE be a good choice over PHP for a social networking application in terms of performance, scalabilty & complexities? 2.) Another possible implementation strategy, Is it suitable to have backend alone in Java and rest in PHP? 3.) What differences(as compared to PHP) it makes in terms of costs at various stages of application development, deployment and maintenance ? 4.) What are the things to keep in mind as we move along with Java development& deployment(as we are relatively new to the Java background) ? 5.) If you could list some major production deployments of similar type(social network) applications in Java. Thank you!

    Read the article

  • Google App Engine application instance recycling and response times...

    - by Konrad
    Hi, I posted this on GAE for Java group, but I hope to get some answers here quicker :) I decided to do some long-run performance tests on my application. I created some small client hitting app every 5-30 minutes and I run 3-5 of threads with such client. I noticed huge differenced in response times and started to investigate issue. I found reason very quick. I am experiencing same issues as described in following topics: Uneven response time between connection to server to first byte sent Application instances seem to be too aggressively recycled Getting 'Request was aborted after waiting too long to attempt to service your request.' after application idle I am using Springframework, it tkes around 18-20s to start app instance, which is causing response times to take from 1s (when requests hits running app - very rare) to 22s when fresh application is created. Is there any solution for this? I was thinking about creating most basic servlet performing critical tasks (serving API call) and leave UI as is. But then I would loose all benefits of Springframework. Is there any solution for this? After solving (hacking) numerous constrains of App Engine which I hit while developing my app that is the one I think will make me move out of App Engine... that's simply to much to all the time think how to win with GAE problems than how to solve my application problems... Any help? Regards Konrad

    Read the article

  • Modify code to change timestamp timezone in sitemap

    - by Aahan Krish
    Below is the code from a plugin I use for sitemaps. I would like to know if there's a way to "enforce" a different timezone on all date variable and functions in it. If not, how do I modify the code to change the timestamp to reflect a different timezone? Say for example, to America/New_York timezone. Please look for date to quickly get to the appropriate code blocks. Code on Pastebin. <?php /** * @package XML_Sitemaps */ class WPSEO_Sitemaps { ..... /** * Build the root sitemap -- example.com/sitemap_index.xml -- which lists sub-sitemaps * for other content types. * * @todo lastmod for sitemaps? */ function build_root_map() { global $wpdb; $options = get_wpseo_options(); $this->sitemap = '<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">' . "\n"; $base = $GLOBALS['wp_rewrite']->using_index_permalinks() ? 'index.php/' : ''; // reference post type specific sitemaps foreach ( get_post_types( array( 'public' => true ) ) as $post_type ) { if ( $post_type == 'attachment' ) continue; if ( isset( $options['post_types-' . $post_type . '-not_in_sitemap'] ) && $options['post_types-' . $post_type . '-not_in_sitemap'] ) continue; $count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(ID) FROM $wpdb->posts WHERE post_type = %s AND post_status = 'publish' LIMIT 1", $post_type ) ); // don't include post types with no posts if ( !$count ) continue; $n = ( $count > 1000 ) ? (int) ceil( $count / 1000 ) : 1; for ( $i = 0; $i < $n; $i++ ) { $count = ( $n > 1 ) ? $i + 1 : ''; if ( empty( $count ) || $count == $n ) { $date = $this->get_last_modified( $post_type ); } else { $date = $wpdb->get_var( $wpdb->prepare( "SELECT post_modified_gmt FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = %s ORDER BY post_modified_gmt ASC LIMIT 1 OFFSET %d", $post_type, $i * 1000 + 999 ) ); $date = date( 'c', strtotime( $date ) ); } $this->sitemap .= '<sitemap>' . "\n"; $this->sitemap .= '<loc>' . home_url( $base . $post_type . '-sitemap' . $count . '.xml' ) . '</loc>' . "\n"; $this->sitemap .= '<lastmod>' . htmlspecialchars( $date ) . '</lastmod>' . "\n"; $this->sitemap .= '</sitemap>' . "\n"; } } // reference taxonomy specific sitemaps foreach ( get_taxonomies( array( 'public' => true ) ) as $tax ) { if ( in_array( $tax, array( 'link_category', 'nav_menu', 'post_format' ) ) ) continue; if ( isset( $options['taxonomies-' . $tax . '-not_in_sitemap'] ) && $options['taxonomies-' . $tax . '-not_in_sitemap'] ) continue; // don't include taxonomies with no terms if ( !$wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->term_taxonomy WHERE taxonomy = %s AND count != 0 LIMIT 1", $tax ) ) ) continue; // Retrieve the post_types that are registered to this taxonomy and then retrieve last modified date for all of those combined. $taxobj = get_taxonomy( $tax ); $date = $this->get_last_modified( $taxobj->object_type ); $this->sitemap .= '<sitemap>' . "\n"; $this->sitemap .= '<loc>' . home_url( $base . $tax . '-sitemap.xml' ) . '</loc>' . "\n"; $this->sitemap .= '<lastmod>' . htmlspecialchars( $date ) . '</lastmod>' . "\n"; $this->sitemap .= '</sitemap>' . "\n"; } // allow other plugins to add their sitemaps to the index $this->sitemap .= apply_filters( 'wpseo_sitemap_index', '' ); $this->sitemap .= '</sitemapindex>'; } /** * Build a sub-sitemap for a specific post type -- example.com/post_type-sitemap.xml * * @param string $post_type Registered post type's slug */ function build_post_type_map( $post_type ) { $options = get_wpseo_options(); ............ // We grab post_date, post_name, post_author and post_status too so we can throw these objects into get_permalink, which saves a get_post call for each permalink. while ( $total > $offset ) { $join_filter = apply_filters( 'wpseo_posts_join', '', $post_type ); $where_filter = apply_filters( 'wpseo_posts_where', '', $post_type ); // Optimized query per this thread: http://wordpress.org/support/topic/plugin-wordpress-seo-by-yoast-performance-suggestion // Also see http://explainextended.com/2009/10/23/mysql-order-by-limit-performance-late-row-lookups/ $posts = $wpdb->get_results( "SELECT l.ID, post_content, post_name, post_author, post_parent, post_modified_gmt, post_date, post_date_gmt FROM ( SELECT ID FROM $wpdb->posts {$join_filter} WHERE post_status = 'publish' AND post_password = '' AND post_type = '$post_type' {$where_filter} ORDER BY post_modified ASC LIMIT $steps OFFSET $offset ) o JOIN $wpdb->posts l ON l.ID = o.ID ORDER BY l.ID" ); /* $posts = $wpdb->get_results("SELECT ID, post_content, post_name, post_author, post_parent, post_modified_gmt, post_date, post_date_gmt FROM $wpdb->posts {$join_filter} WHERE post_status = 'publish' AND post_password = '' AND post_type = '$post_type' {$where_filter} ORDER BY post_modified ASC LIMIT $steps OFFSET $offset"); */ $offset = $offset + $steps; foreach ( $posts as $p ) { $p->post_type = $post_type; $p->post_status = 'publish'; $p->filter = 'sample'; if ( wpseo_get_value( 'meta-robots-noindex', $p->ID ) && wpseo_get_value( 'sitemap-include', $p->ID ) != 'always' ) continue; if ( wpseo_get_value( 'sitemap-include', $p->ID ) == 'never' ) continue; if ( wpseo_get_value( 'redirect', $p->ID ) && strlen( wpseo_get_value( 'redirect', $p->ID ) ) > 0 ) continue; $url = array(); $url['mod'] = ( isset( $p->post_modified_gmt ) && $p->post_modified_gmt != '0000-00-00 00:00:00' ) ? $p->post_modified_gmt : $p->post_date_gmt; $url['chf'] = 'weekly'; $url['loc'] = get_permalink( $p ); ............. } /** * Build a sub-sitemap for a specific taxonomy -- example.com/tax-sitemap.xml * * @param string $taxonomy Registered taxonomy's slug */ function build_tax_map( $taxonomy ) { $options = get_wpseo_options(); .......... // Grab last modified date $sql = "SELECT MAX(p.post_date) AS lastmod FROM $wpdb->posts AS p INNER JOIN $wpdb->term_relationships AS term_rel ON term_rel.object_id = p.ID INNER JOIN $wpdb->term_taxonomy AS term_tax ON term_tax.term_taxonomy_id = term_rel.term_taxonomy_id AND term_tax.taxonomy = '$c->taxonomy' AND term_tax.term_id = $c->term_id WHERE p.post_status = 'publish' AND p.post_password = ''"; $url['mod'] = $wpdb->get_var( $sql ); $url['chf'] = 'weekly'; $output .= $this->sitemap_url( $url ); } } /** * Build the <url> tag for a given URL. * * @param array $url Array of parts that make up this entry * @return string */ function sitemap_url( $url ) { if ( isset( $url['mod'] ) ) $date = mysql2date( "Y-m-d\TH:i:s+00:00", $url['mod'] ); else $date = date( 'c' ); $output = "\t<url>\n"; $output .= "\t\t<loc>" . $url['loc'] . "</loc>\n"; $output .= "\t\t<lastmod>" . $date . "</lastmod>\n"; $output .= "\t\t<changefreq>" . $url['chf'] . "</changefreq>\n"; $output .= "\t\t<priority>" . str_replace( ',', '.', $url['pri'] ) . "</priority>\n"; if ( isset( $url['images'] ) && count( $url['images'] ) > 0 ) { foreach ( $url['images'] as $img ) { $output .= "\t\t<image:image>\n"; $output .= "\t\t\t<image:loc>" . esc_html( $img['src'] ) . "</image:loc>\n"; if ( isset( $img['title'] ) ) $output .= "\t\t\t<image:title>" . _wp_specialchars( html_entity_decode( $img['title'], ENT_QUOTES, get_bloginfo('charset') ) ) . "</image:title>\n"; if ( isset( $img['alt'] ) ) $output .= "\t\t\t<image:caption>" . _wp_specialchars( html_entity_decode( $img['alt'], ENT_QUOTES, get_bloginfo('charset') ) ) . "</image:caption>\n"; $output .= "\t\t</image:image>\n"; } } $output .= "\t</url>\n"; return $output; } /** * Get the modification date for the last modified post in the post type: * * @param array $post_types Post types to get the last modification date for * @return string */ function get_last_modified( $post_types ) { global $wpdb; if ( !is_array( $post_types ) ) $post_types = array( $post_types ); $result = 0; foreach ( $post_types as $post_type ) { $key = 'lastpostmodified:gmt:' . $post_type; $date = wp_cache_get( $key, 'timeinfo' ); if ( !$date ) { $date = $wpdb->get_var( $wpdb->prepare( "SELECT post_modified_gmt FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = %s ORDER BY post_modified_gmt DESC LIMIT 1", $post_type ) ); if ( $date ) wp_cache_set( $key, $date, 'timeinfo' ); } if ( strtotime( $date ) > $result ) $result = strtotime( $date ); } // Transform to W3C Date format. $result = date( 'c', $result ); return $result; } } global $wpseo_sitemaps; $wpseo_sitemaps = new WPSEO_Sitemaps();

    Read the article

  • To Ajax or Not to Ajax a listing page

    - by kaivalya
    Here i am talking about product listing pages where there are multiple filters that filter the list of products appearing on the page like product types, categories price range etc. I have done such pages using both ajax and no ajax way in the past. What I like about using ajax in such page is that, when filters are selected I only update the section that contains the product list. There is no need to refresh the whole page which could end up re-loading the images on top bar, banners etc and slow down the user performance. Ajax way in my opinion becomes more compact and responsive from user experience. Down side for ajax route for me is; since filter states are not maintained in the URL I end up maintaining them on the server. This becomes complicated if I want to handle multi window scenarios and it is also costly to maintain such state on server memory for each session. Not using ajax and simply keeping all filter values on url and refreshing the page is quite simple but the luxury of refreshing only the pane that really needs to be refreshed is lost. Lately I am seeing a lot of large scale e-commerce sites that are using non-ajax approach on their listing pages and this is making me question one more time if it might be more efficient to build non-ajax listing make due to the long term maintenance ease and sacrifice a little bit from user experience. I am about to start implementing a new listing page for a product which I have the flexibility to go either way and I would appreciate your inputs.

    Read the article

  • Core Data migration of to-one relationship to to-many relationship

    - by westsider
    I have a deployed app that samples measurements from sensors (e.g., Temp °C, Pressure kPa). The user can create Experiments and collect samples. Each sample is stored as a Run, such that there is a one-to-many relationship from Experiment to Run. In the interest of performance, Run has a to-one relationship with Data entity (which is where the actual raw data is stored); this allows some Run attributes to be loaded without necessarily loading lots of data. Most of our sensors have multiple measurements, so it would be nice to store all the data that is actually being sampled. But this means that the Run <--- Data relationship needs to become Run <-- Data (to use Xcode's convention). I am faced with trying to migrate data from old Run to-one Data model to new Run to-many Data model. Can this be done using Mapping Models? If so, does anyone have any pointers to examples? If not, does anyone have any pointers to examples of how to do that? Thanks for any pointers or advice.

    Read the article

  • MVC ASP.NET, ObjectContext and Ajax. Weird Behaviour

    - by fabianadipolo
    Hi, i've been creating a web application in mvc asp.net. I have three different project/solutions. One solution contains the model in EF (DAL) and all the methods to add, update, delete and query the objects in the model, the objectcontext is managed here in a per request basis. Other solution contains a content management system in wich authorized users insert, delete, update and access objects through the DAL mentioned before. And the last solution contains the web page that is accessed by all users and where the only operations executed are selects, no update, inserts or deletes here. All the selects are executed against the DAL mentioned before (the first solution). The problem here is that i'm not sure whether an HttpContext lifespan ObjectContext is the best solution. I have a lot of ajax calls in my web app and i'm not sure if an httpcontext could interfere with the performance of the application. I've been noticed that in some cases, specially when someone is working in the content manager inserting, updating or deleting, when you try to click on any link of the user web application (the web app that is accessed by any user - the third one that i mentioned before) the web page freezes and it remains stucked transferring data. In order to stop that behaviour you have to stop and refresh or click several times on the link. Excuse me for my bad english. I hope you could understand and could help me to solve this issue. Thanx in advance.

    Read the article

  • WordPress > Optimizing a query to show recent posts with a "View All" link when postcount exceeds ma

    - by Scott B
    I have a setting in my theme that allows the site owner to set the maximum number of posts ($maxPosts) to display in a "Recent Posts" menu. I'm using a custom script to generate the recent posts (because the Recent Posts widget does not highlight the current page, which I need for my css). My menu also is set up to display a "View All" link below the post listing, but only if the actual post count is $maxposts I'm trying to work out the best method for getting the post count and comparing it to $maxposts in order to determine whether or not to show a "View All" link. I'm sure there's probably a better way, but here's my code. I'm looking to optimize it to support very large post counts... $cat=get_cat_ID('excludeFromRecentPosts'); $catHidden=get_cat_ID('hidden'); $myquery = new WP_Query(); $myquery->query(array( 'cat' => "-$cat,-$catHidden", 'post_not_in' => get_option('sticky_posts') )); $myrecentpostscount = $myquery->found_posts; if ($myrecentpostscount > 0) { //show the menu if ($myrecentpostscount > $maxPosts) { //show "View All" link } } I really only need to determine if the total post count from the query is greater than the maxPost setting in order to determine whether to show the "View All" link, so I'm wondering if, in the case there are thousands of posts matching the criteria, to avoid performance issues, I don't need to get a count of all of them. I just need to count up until the point of maxPosts + 1, and that's where I'm struggling a bit because the user could elect to make maxPosts = -1 which means they want to show all posts. But this would be impractical, so I would probably set a upper limit of 20...

    Read the article

  • Use Java exceptions internally for REST API user errors?

    - by user303396
    We have a REST API that works great. We're refactoring and deciding how to internally handle errors by the users of our API. For example the user needs to specify the "movie" url parameter which should take the value of "1984", "Crash", or "Avatar". First we check to see if it has a valid value. What would be the best approach if the movie parameter is invalid? return null from one of the internal methods and check for the null in the main API call method throw an exception from the internal method and catch exceptions in the main API method I think it would make our code more readable and elegant to use exceptions. However, we're reluctant because we'd be potentially throwing many exceptions because of user API input errors, our code could be perfect. This doesn't seem to be the proper use of exceptions. If there are heavy performance penalties with exceptions, which would make sense with stack traces needing to be collected, etc., then we're unnecessarily spending resources when all we need to do is tell the user the parameter is wrong. These are REST API methods, so we're not propogating the exceptions to the users of the API, nor would we want to even if possible. So what's the best practice here? Use ugly nulls or use java's exception mechanism?

    Read the article

  • Speed up bitstring/bit operations in Python?

    - by Xavier Ho
    I wrote a prime number generator using Sieve of Eratosthenes and Python 3.1. The code runs correctly and gracefully at 0.32 seconds on ideone.com to generate prime numbers up to 1,000,000. # from bitstring import BitString def prime_numbers(limit=1000000): '''Prime number generator. Yields the series 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 ... using Sieve of Eratosthenes. ''' yield 2 sub_limit = int(limit**0.5) flags = [False, False] + [True] * (limit - 2) # flags = BitString(limit) # Step through all the odd numbers for i in range(3, limit, 2): if flags[i] is False: # if flags[i] is True: continue yield i # Exclude further multiples of the current prime number if i <= sub_limit: for j in range(i*3, limit, i<<1): flags[j] = False # flags[j] = True The problem is, I run out of memory when I try to generate numbers up to 1,000,000,000. flags = [False, False] + [True] * (limit - 2) MemoryError As you can imagine, allocating 1 billion boolean values (1 byte 4 or 8 bytes (see comment) each in Python) is really not feasible, so I looked into bitstring. I figured, using 1 bit for each flag would be much more memory-efficient. However, the program's performance dropped drastically - 24 seconds runtime, for prime number up to 1,000,000. This is probably due to the internal implementation of bitstring. You can comment/uncomment the three lines to see what I changed to use BitString, as the code snippet above. My question is, is there a way to speed up my program, with or without bitstring?

    Read the article

  • Is there any danger in calling free() or delete instead of delete[]? [closed]

    - by Matt Joiner
    Possible Duplicate: ( POD )freeing memory : is delete[] equal to delete ? Does delete deallocate the elements beyond the first in an array? char *s = new char[n]; delete s; Does it matter in the above case seeing as all the elements of s are allocated contiguously, and it shouldn't be possible to delete only a portion of the array? For more complex types, would delete call the destructor of objects beyond the first one? Object *p = new Object[n]; delete p; How can delete[] deduce the number of Objects beyond the first, wouldn't this mean it must know the size of the allocated memory region? What if the memory region was allocated with some overhang for performance reasons? For example one could assume that not all allocators would provide a granularity of a single byte. Then any particular allocation could exceed the required size for each element by a whole element or more. For primitive types, such as char, int, is there any difference between: int *p = new int[n]; delete p; delete[] p; free p; Except for the routes taken by the respective calls through the delete-free deallocation machinery?

    Read the article

  • Best way to pan & scan images with jquery

    - by guy
    Hello, I am trying to make an image pan & scan system. I have a slider that zooms the image (that can be dragged) and also a small map in the corner of the image (that can also be dragged). You can see a rough example here (sorry, I am not allowed to use the design, so it's not formatted): http://lighe.madetokill.com/test/test.html My problem is that although it works great in firefox and opera, it stutters in chrome, safari and IE (it doesn't currently work in IE) at any zoom level except 100% (at 100% it's butter smooth). What is the reason for webkit's poor performance? Am I implementing this wrong? I am basically changing the margin-left and margin-top properties of the image. I know this is fast enough since at 100% it's perfectly smooth. Would I be better off using canvas? I am trying to avoid flash (or any other plugins) if possible. Also please note this is work in progress, there are other bugs except this, so do not bother with those :) Thanks in advance!

    Read the article

  • Plot in GNU PLOT

    - by guddi
    I have to plot many lines in GNU PLOT.No problem with the X axis. The problem that I am facing is that most of the plotted lines are at yscale [0-0.05] ,few at range 60-70 and rest at 600-700. These numbers correspond to the y axis scale values. But after I plot I can see only 3 sets of lines all messed up. There is no clearity between the lines. Line at 0 and the line at 0.003 look like one single line. If I set yrange[0:0.05], the lines between this range are clearly vissible. But I want all the lines in the same graph. I have heard of breaking axis's and multi plotting..Can they be useful? how to implement them. Anyone pls help me. Below is the sript set terminal png size 1300,1200 enhanced font 'Verdana,20 set output ' output .png’ set key font 'Verdana,16' set key bottom outside set yrange[500:1000] set xtics("25k" 25000,"50k" 50000,"75k" 75000,"100k" 100000) set grid set title 'Performance Metrics' set ylabel 'Metrices' set xlabel 'FES' plot ' input ' using 1:2 title ' A' with linespoints linewidth 4, ' input ' using 1:3 title B'with linespoints linewidth 4, 'input ' using 1:4 title ' c' with linespoints linewidth 4, 'input ' using 1:5 title 'D' with linespoints linewidth 4, ' input ' using 1:6 title 'E' with linespoints linewidth 4, ' input ' using 1:7 title 'F' with linespoints linewidth 4, ' input ' using 1:8 title 'G' with linespoints linewidth 4, ' input ' using 1:9 title ' H ' with linespoints linewidth 4, ' input ' using 1:10 title ' I' Metric ' with linespoints linewidth 4 set output set terminal windows input.dat is something like this: 25 0.002 0.05 899 455 444 0.08 0.00004 900 700 0.003 This way i have other rows. I have shown only the first one

    Read the article

  • Multiple sendto() using UDP socket

    - by ereOn
    Hi, I have a network software which uses UDP to communicate with other instances of the same program. For different reasons, I must use UDP here. I recently had problems sending huge ammounts of data over UDP and had to implement a fragmentation system to split my messages into small data chunks. So far, it worked well but I now encounter an issue when I have to send a lot of data chunks. I have the following algorithm: Split message into small data chunks (around 1500 bytes) Iterate over the data chunks list and for each, send it using sendto() However, when I send a lot of data chunks, the receiver only gets the first 6 messages. Sometimes it misses the sixth and receives the seventh. It depends. Anyway, sendto() always indicates success. This always happen when I test my software over a loopback interface (127.0.0.1) but never over my LAN network. If I add something like std::cout << "test" << std::endl; between the sendto() then every frame is received. I am aware that UDP allows packet loss and that my frames might be loss for a lot of reasons and I suppose it has to do with the rate I am sending the data chunks at. What would be the right approach here ? Implementing some acknowledgement mechanism (just like TCP) seems overkill. Adding some arbitrary waiting time between the sendto() is ugly and will probably decrease performance. Increasing (if possible) the receiver UDP internal buffer ? I don't even know if this is possible. Something else ? I really need your advices here. Thank very much.

    Read the article

  • Can't connect to local MySQL server through socket

    - by Martin
    I was trying to tune the performance of a running mysql-server by running this command: mysqld_safe --key_buffer_size=64M --table_cache=256 --sort_buffer_size=4M --read_buffer_size=1M & After this i'm unable to connect mysql from the server where mysql is running. I get this error: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) However, luckily i can still connect to mysql remotely. So all my webservers still have access to mysql and are running without any problems. Because of this though i don't want to try to restart the mysql server since that will probably fuck everything up. Now i know that mysqld_safe is starting the mysql-server, and since the mysql server was already running i guess it's some kind of problem with two mysql servers running and listening to the same port. Is there some way to solve this problem without restarting the initial mysql server? UPDATE: This is what ps xa | grep "mysql" says: 11672 ? S 0:00 /bin/sh /usr/bin/mysqld_safe 11780 ? Sl 175:04 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306 11781 ? S 0:00 logger -t mysqld -p daemon.error 12432 pts/0 R+ 0:00 grep mysql

    Read the article

  • Oracle rownum in db2 - Java data archiving

    - by HonorGod
    I have a data archiving process in java that moves data between db2 and sybase. FYI - This is not done through any import/export process because there are several conditions on each table that are available on run-time and so this process is developed in java. Right now I have single DatabaseReader and DatabaseWriter defined for each source and destination combination so that data is moved in multiple threads. I guess I wanted to expand this further where I can have Multiple DatabaseReaders and Multiple DatabaseWriters defined for each source and destination combination. So, for example if the source data is about 100 rows and I defined 10 readers and 10 writer, each reader will read 10 rows and give them to the writer. I hope process will give me extreme performance depending on the resources available on the server [CPU, Memory etc]. But I guess the problem is these source tables do not have primary keys and it is extremely difficult to grab rows in multiple sets. Oracle provides rownum concept and i guess the life is much simpler there....but how about db2? How can I achieve this behavior with db2? Is there a way to say fetch first 10 records and then fetch next 10 records and so on? Any suggestions / ideas ? Db2 Version - DB2 v8.1.0.144 Fix Pack Num - 16 Linux

    Read the article

  • Browser Based Streaming Video/Audio (not progressive download)

    - by Josh
    Hello, I am trying to understand conceptually the best way to deliver real streaming audio and video content. I would want it to be consumed with a web browser, utilizing the least amount of proprietary technology. I wouldn't be serving static files and using progressive download, this would be real audio streams being captured live. How does one broadcast a stream that will be reasonably in sync with the source? What kind of protocol is suitable? Edit: In research I've found that there are a few protocols: RTSP, HTTP Streaming, RTMP, and RTP. HTTP streaming is somewhat unsuitable if you are streaming a live performance/communication of some kind because it relies on TCP (as its HTTP based) and you don't lose packets. In a low bandwidth situation, the client can get significantly behind in playback. ref RTMP is a proprietary technology, requiring flash media server. Crap on that. The reason I looked at flash is because they are extremely flexible as far as user experience goes. SoundManager2 provides an excellent javascript interface for playing media with flash. This is what I would look for in a client application. RTSP/RTP is what Microsoft switched to using, deprecating their MMS protocol. RTSP is the control protocol. Its similar to HTTP with a few distinct difference -- server can also talk to the client, and there are additional commands, like PAUSE. Its also a stateful protocol, which is maintained with a session id. RTP is the protocol for delivering the payload (encoded audio or video). There are a few open sourced projects, one of them being supported by apple here. It seems like this might do what I want it to, and it looks like quite a few players support it. It sounds like it would be suitable for a "live" broadcast from this page here. Thanks, Josh

    Read the article

< Previous Page | 452 453 454 455 456 457 458 459 460 461 462 463  | Next Page >