Search Results

Search found 23103 results on 925 pages for 'performance issues and ha'.

Page 380/925 | < Previous Page | 376 377 378 379 380 381 382 383 384 385 386 387  | Next Page >

  • Changing App.config at Runtime

    - by born to hula
    I'm writing a test winforms / C# / .NET 3.5 application for the system we're developing and we fell in the need to switch between .config files at runtime, but this is turning out to be a nightmare. Here's the scene: the Winforms application is aimed at testing a WebApp, divided into 5 subsystems. The test proccess works with messages being sent between the subsystems, and for this proccess to be sucessful each subsystem got to have its own .config file. For my Test Application I wrote 5 separate configuration files. I wish I was able to switch between these 5 files during runtime, but the problem is: I can programatically edit the application .config file inumerous times, but these changes will only take effect once. I've been searching a long time for a form to address this problem but I still wasn't sucessful. I know the problem definition may be a bit confusing but I would really appreciate it if someone helped me. Thanks in advance! --- UPDATE 01-06-10 --- There's something I didn't mention before. Originally, our system is a Web Application with WCF calls between each subsystem. For performance testing reasons (we're using ANTS 4), we had to create a local copy of the assemblies and reference them from the test project. It may sound a bit wrong, but we couldn't find a satisfying way to measure performance of a remote application. --- End Update --- Here's what I'm doing: public void UpdateAppSettings(string key, string value) { XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile); foreach (XmlElement item in xmlDoc.DocumentElement) { foreach (XmlNode node in item.ChildNodes) { if (node.Name == key) { node.Attributes[0].Value = value; break; } } } xmlDoc.Save(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile); System.Configuration.ConfigurationManager.RefreshSection("section/subSection"); }

    Read the article

  • Efficient Context-Free Grammar parser, preferably Python-friendly

    - by Max Shawabkeh
    I am in need of parsing a small subset of English for one of my project, described as a context-free grammar with (1-level) feature structures (example) and I need to do it efficiently . Right now I'm using NLTK's parser which produces the right output but is very slow. For my grammar of ~450 fairly ambiguous non-lexicon rules and half a million lexical entries, parsing simple sentences can take anywhere from 2 to 30 seconds, depending it seems on the number of resulting trees. Lexical entries have little to no effect on performance. Another problem is that loading the (25MB) grammar+lexicon at the beginning can take up to a minute. From what I can find in literature, the running time of the algorithm used to parse such a grammar (Earley or CKY) should be linear to the size of the grammar and cubic to the size of the input token list. My experience with NLTK indicates that ambiguity is what hurts the performance most, not the absolute size of the grammar. So now I'm looking for a CFG parser to replace NLTK. I've been considering PLY but I can't tell whether it supports feature structures in CFGs, which are required in my case, and the examples I've seen seem to be doing a lot of procedural parsing rather than just specifying a grammar. Can anybody show me an example of PLY both supporting feature structs and using a declarative grammar? I'm also fine with any other parser that can do what I need efficiently. A Python interface is preferable but not absolutely necessary.

    Read the article

  • What are alternatives to Win32 PulseEvent() function?

    - by Bill
    The documentation for the Win32 API PulseEvent() function (kernel32.dll) states that this function is “… unreliable and should not be used by new applications. Instead, use condition variables”. However, condition variables cannot be used across process boundaries like (named) events can. I have a scenario that is cross-process, cross-runtime (native and managed code) in which a single producer occasionally has something interesting to make known to zero or more consumers. Right now, a well-known named event is used (and set to signaled state) by the producer using this PulseEvent function when it needs to make something known. Zero or more consumers wait on that event (WaitForSingleObject()) and perform an action in response. There is no need for two-way communication in my scenario, and the producer does not need to know if the event has any listeners, nor does it need to know if the event was successfully acted upon. On the other hand, I do not want any consumers to ever miss any events. In other words, the system needs to be perfectly reliable – but the producer does not need to know if that is the case or not. The scenario can be thought of as a “clock ticker” – i.e., the producer provides a semi-regular signal for zero or more consumers to count. And all consumers must have the correct count over any given period of time. No polling by consumers is allowed (performance reasons). The ticker is just a few milliseconds (20 or so, but not perfectly regular). Raymen Chen (The Old New Thing) has a blog post pointing out the “fundamentally flawed” nature of the PulseEvent() function, but I do not see an alternative for my scenario from Chen or the posted comments. Can anyone please suggest one? Please keep in mind that the IPC signal must cross process boundries on the machine, not simply threads. And the solution needs to have high performance in that consumers must be able to act within 10ms of each event.

    Read the article

  • How can I write reusable Javascript?

    - by RenderIn
    I've started to wrap my functions inside of Objects, e.g.: var Search = { carSearch: function(color) { }, peopleSearch: function(name) { }, ... } This helps a lot with readability, but I continue to have issues with reusabilty. To be more specific, the difficulty is in two areas: Receiving parameters. A lot of times I will have a search screen with multiple input fields and a button that calls the javascript search function. I have to either put a bunch of code in the onclick of the button to retrieve and then martial the values from the input fields into the function call, or I have to hardcode the HTML input field names/IDs so that I can subsequently retrieve them with Javascript. The solution I've settled on for this is to pass the field names/IDs into the function, which it then uses to retrieve the values from the input fields. This is simple but really seems improper. Returning values. The effect of most Javascript calls tends to be one in which some visual on the screen changes directly, or as a result of another action performed in the call. Reusability is toast when I put these screen-altering effects at the end of a function. For example, after a search is completed I need to display the results on the screen. How do others handle these issues? Putting my thinking cap on leads me to believe that I need to have an page-specific layer of Javascript between each use in my application and the generic methods I create which are to be used application-wide. Using the previous example, I would have a search button whose onclick calls a myPageSpecificSearchFunction, in which the search field IDs/names are hardcoded, which marshals the parameters and calls the generic search function. The generic function would return data/objects/variables only, and would not directly read from or make any changes to the DOM. The page-specific search function would then receive this data back and alter the DOM appropriately. Am I on the right path or is there a better pattern to handle the reuse of Javascript objects/methods?

    Read the article

  • Better why of looping to detect change.

    - by Dremation
    As of now I'm using a while(true) method to detect changes in memory. The problem with this is it's kill the applications performance. I have a list of 30 pointers that need checked as rapidly as possible for changes, without sacrificing a huge performance loss. Anyone have ideas on this? memScan = new Thread(ScanMem); public static void ScanMem() { int i = addy.Length; while (true) { Thread.Sleep(30000); //I do this to cut down on cpu usage for (int j = 0; j < i; j++) { string[] values = addy[j].Split(new char[] { Convert.ToChar(",") }); //MessageBox.Show(values[2]); try { if (Memory.Scanner.getIntFromMem(hwnd, (IntPtr)Convert.ToInt32(values[0], 16), 32).ToString() != values[1].ToString()) { //Ok, it changed lets do our work //work if (Globals.Working) return; SomeFunction("Results: " + values[2].ToString(), "Memory"); Globals.Working = true; }//end if }//end try catch { } }//end for }//end while }//end void

    Read the article

  • Product Catalog Schema design

    - by FlySwat
    I'm building a proof of concept schema for a product catalog to possibly replace a very aging and crufty one we use. In our business, we sell both physical materials and services (one time and reoccurring charges). The current catalog schema has each distinct category broken out into individual tables, while this is nicely normalized and performs well, it is fairly difficult to extend. Adding a new attribute to a particular product involves changing the table schema and backpopulating old data. An idea I've been toying with has been something along the line of a base set of entity tables in 3rd normal form, these will contain the facts that are common among ALL products. Then, I'd like to build an Attribute-Entity-Value schema that allows each entity type to be extended in a flexible way using just data and no schema changes. Finally, I'd like to denormalize this data model into materialized views for each individual entity type. This views are what the application would access. We also have many tables that contain business rules and compatibility rules. These would join against the base entity tables instead of the views. My big concerns here are: Performance - Attribute-Entity-Value schemas are flexible, but typically perform poorly, should I be concerned? More Performance - Denormalizing using materialized views may have some risks, I'm not positive on this yet. Complexity - While this schema is flexible and maintainable using just data, I worry that the complexity of the design might make future schema changes difficult. For those who have designed product catalogs for large scale enterprises, am I going down the totally wrong path? Is there any good best practice schema design reading available for product catalogs?

    Read the article

  • Bitbucket API authentication with Python's HTTPBasicAuthHandler

    - by jbochi
    I'm trying to get the list of issues on a private repository using bitbucket's API. I have confirmed that HTTP Basic authentication works with hurl, but I am unable to authenticate in Python. Adapting the code from this tutorial, I have written the following script. import cookielib import urllib2 class API(): api_url = 'http://api.bitbucket.org/1.0/' def __init__(self, username, password): self._opener = self._create_opener(username, password) def _create_opener(self, username, password): cj = cookielib.LWPCookieJar() cookie_handler = urllib2.HTTPCookieProcessor(cj) password_manager = urllib2.HTTPPasswordMgrWithDefaultRealm() password_manager.add_password(None, self.api_url, username, password) auth_handler = urllib2.HTTPBasicAuthHandler(password_manager) opener = urllib2.build_opener(cookie_handler, auth_handler) return opener def get_issues(self, username, repository): query_url = self.api_url + 'repositories/%s/%s/issues/' % (username, repository) try: handler = self._opener.open(query_url) except urllib2.HTTPError, e: print e.headers raise e return handler.read() api = API(username='my_username', password='XXXXXXXX') api.get_issues('my_username', 'my_repository') results in: >>> Server: nginx/0.7.62 Date: Mon, 19 Apr 2010 16:15:06 GMT Content-Type: text/plain Connection: close Vary: Authorization,Cookie Content-Length: 9 Traceback (most recent call last): File "C:/USERS/personal/bitbucket-burndown/bitbucket-api.py", line 29, in <module> print api.get_issues('my_username', 'my_repository') File "C:/USERS/personal/bitbucket-burndown/bitbucket-api.py", line 25, in get_issues raise e HTTPError: HTTP Error 401: UNAUTHORIZED api.get_issues('jespern', 'bitbucket') works like a charm. What's wrong with my code?

    Read the article

  • How should bug tracking and help tickets integrate?

    - by Max Schmeling
    I have a little experience with bug tracking systems such as FogBugz where help tickets are issues are (or can be) bugs, and I have some experience using a bug tracking system internally completely separate from a help center system. My question is, in a company with an existing (home-grown) help center system where replacing it is not an option, how should a bug tracking system (probably Mantis) be integrated into the process? Right now help tickets get put in for issues, questions, etc and they get assigned to the appropriate person (PC Tech, Help Desk staff, or if it's an application issue they can't solve in the help desk it gets assigned to a developer). A user can put a request for small modifications or fixes to an application in a help ticket and the developer it gets assigned to will make the change at some point, apply their time to that ticket, and then close the ticket when it goes to production. We don't currently have a bug tracking system, so I'm looking into the best way to integrate one. Should we just take the help tickets and put it into the bug tracking system if it's a bug (or issue or feature request) and then close the ticket if it's not an emergency fix? We probably don't want to expose the bug tracking system to anyone else as they wouldn't know what to put in the help center system and what to put in the bug tracker... right? Any thoughts? Suggestions? Tips? Advice? To-dos? Not to-dos? etc...

    Read the article

  • Pros & Cons of Google App Engine

    - by Rishi
    Pros & Cons of Google App Engine [An Updated List 21st Aug 09] Help me Compile a List of all the Advantages & Disadvantages of Building an Application on the Google App Engine Pros: 1) No Need to buy Servers or Server Space (no maintenance). 2) Makes solving the problem of scaling much easier. Cons: 1) Locked into Google App Engine ?? 2)Developers have read-only access to the filesystem on App Engine. 3)App Engine can only execute code called from an HTTP request (except for scheduled background tasks). 4)Users may upload arbitrary Python modules, but only if they are pure-Python; C and Pyrex modules are not supported. 5)App Engine limits the maximum rows returned from an entity get to 1000 rows per Datastore call. 6)Java applications may only use a subset (The JRE Class White List) of the classes from the JRE standard edition. 7)Java applications cannot create new threads. Known Issues!! http://code.google.com/p/googleappengine/issues/list Hard limits Apps per developer - 10 Time per request - 30 sec Files per app - 3,000 HTTP response size - 10 MB Datastore item size - 1 MB Application code size - 150 MB Pro or Con? App Engine's infrastructure removes many of the system administration and development challenges of building applications to scale to millions of hits. Google handles deploying code to a cluster, monitoring, failover, and launching application instances as necessary. While other services let users install and configure nearly any *NIX compatible software, App Engine requires developers to use Python or Java as the programming language and a limited set of APIs. Current APIs allow storing and retrieving data from a BigTable non-relational database; making HTTP requests; sending e-mail; manipulating images; and caching. Most existing Web applications can't run on App Engine without modification, because they require a relational database.

    Read the article

  • MPMoviePlayerController - streaming works on 3GS, not on anything pre-3GS

    - by Canada Dev
    I am having some serious issues and annoyances with MPMoviePlayerController. In my app you can watch trailers for some movies in .mov format. I have tested with a friend and had users report that it does not work on their device, which are all 3G. I have tested on my own, a 3GS and playback works fine. I have tried on a 1st gen iPhone and it doesn't work. So I am lead to believe it's a memory issue, and that it's simply stopping the playback and returning to the previous screen. Below is the code I use to launch the player, which is straight out of the MoviePlayer example from Apple. MPMoviePlayerController *mp = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL URLWithString:trailerURL]]; if (mp) { self.moviePlayer = mp; [mp release]; [self.moviePlayer play]; } I have tried to check the NSError from the notifications, but the only thing I get is "An unknown playback error occurred" for both the localizedDescription and localizedRecoverySuggestion, making it impossible to figure out exactly why it's not working. I have seen many examples of people who just have issues with the movie player, but it's starting to annoy me that it sometimes seem to work fine and other times it just doesn't (again, appearing like a memory issue). Thanks for any help/feedback provided

    Read the article

  • C++ .NET DLL vs C# Managed Code ? (File Encrypting AES-128+XTS)

    - by Ranhiru
    I need to create a Windows Mobile Application (WinMo 6.x - C#) which is used to encrypt/decrypt files. However it is my duty to write the encryption algorithm which is AES-128 along with XTS as the mode of operation. RijndaelManaged just doesn't cut it :( Very much slower than DES and 3DES CryptoServiceProviders :O I know it all depends on how good I am at writing the algorithm in the most efficient way. (And yes I my self have to write it from scratch but i can take a look @ other implementations) Nevertheless, does writing a C++ .NET DLL to create the encryption/decryption algorithm + all the file handling and using it from C# have a significant performance advantage OVER writing the encryption algorithm + file handling in completely managed C# code? If I use C++ .NET to create the encryption algorithm, should I use MFC Smart Device DLL or ATL? What is the difference and is there any impact on which one I choose? And can i just add a reference to the C++ DLL from C# or should I use P/Invoke? I am fairly competent with C# than C++ but performance plays a major role as I have convinced my lecturers that AES is a very efficient cryptographic algorithm for resource constrained devices. Thanx a bunch :)

    Read the article

  • iPhone Landscape FAQ and Solutions

    - by Johannes Rudolph
    There has been a lot of confusion and a set of corresponding set of questions here on SO how iPhone applications with proper handling for Landscape/Portrait mode autorotation can be implemented. It is especially difficult to implement such an application when starting in landscape mode is desired. The most common observed effect are scrambled layouts and areas of the screen where touches are no longer recognized. A simple search for questions tagged iphone and landscape reveals these issues, which occur under certain scenarios: Landscape only iPhone app with multiple nibs: App started in Landscape mode, view from first nib is rendered fine, everything view loaded from a different nib is not displayed correctly. Iphone Landscape mode switching to Portraite mode on loading new controller: Self explanatory iPhone: In landscape-only, after first addSubview, UITableViewController doesn’t rotate properly: Same issue as above. iPhone Landscape-Only Utility-Template Application: Layout errors, controller does not seem to recognize the view should be rotated but displays a clipped portrait view in landscape mode, causing half of the screen to stay blank. presentModalViewController in landscape after portrait viewController: Modal views are not correctly rendered either. A set of different solutions have been presented, some of them including completely custom animation via CoreGraphics, while others build on the observation that the first view controller loaded from the main nib is always displayed correct. I have spent a significant amount of time investigating this issue and finally found a solution that is not only a partial solution but should work under all these circumstances. It is my intend with this CW post to provide sort of a FAQ for others having issues with UIViewControllers in Landscape mode. Please provide feedback and help improve the quality of this Post by incorporating any related observations. Feel free to edit and post other/better answers if you know of any.

    Read the article

  • Ibatis startBatch() only works with SqlMapClient's own start and commit transactions, not with Sprin

    - by Brian
    Hi, I'm finding that even though I have code wrapped by Spring transactions, and it commits/rolls back when I would expect, in order to make use of JDBC batching when using Ibatis and Spring I need to use explicit SqlMapClient transaction methods. I.e. this does batching as I'd expect: dao.getSqlMapClient().startTransaction(); dao.getSqlMapClient().startBatch(); int i = 0; for (MyObject obj : allObjects) { dao.storeChange(obj); i++; if (i % DB_BATCH_SIZE == 0) { dao.getSqlMapClient().executeBatch(); dao.getSqlMapClient().startBatch(); } } dao.getSqlMapClient().executeBatch(); dao.getSqlMapClient().commitTransaction(); but if I don't have the opening and closing transaction statements, and rely on Spring to manage things (which is what I want to do!), batching just doesn't happen. Given that Spring does otherwise seem to be handling its side of the bargain regarding transaction management, can anyone advise on any known issues here? (Database is MySQL; I'm aware of the issues regarding its JDBC pseudo-batch approach with INSERT statement rewriting, that's definitely not an issue here)

    Read the article

  • VLC desktop streaming

    - by StackedCrooked
    Edit I stopped using VLC and switched to GMax FLV Encoder. It does a much better job IMO. Original post I am sending my desktop (screen) as an H264 video stream to another machine that saves it to a file using the follwoing command lines: Sender of the stream: vlc -I dummy --sout='#transcode{vcodec=h264,vb=512,scale=0.5} :rtp{mux=ts,dst=192.168.0.1,port=4444}' Receiver of the stream: vlc -I rc rtp://@:4444 --sout='#std{access=file,mux=ps,dst=/home/user/output.mp4}' --ipv4 This works, but there are a few issues: The file is not playable with most players. VLC is able to playback the file but with some weirdness: = it takes about 10 seconds before the playback actually begins. = seeking doesn't work. Can someone point me in the right direction on how to fix these issues? EDIT: I made a little progress. The initial delay in playback is because the player is waiting for a keyframe. By forcing the sender of the stream to create a new key-frame every 4 seconds I could decrease the delay: :screen-fps=10 --sout='#transcode{vcodec=h264,venc=x264{keyint=40},vb=512,scale=0.5} :rtp{mux=ts,dst=192.168.0.1,port=4444}' The seeking problem is not solved however, but I understand it a little better. The RTP stream is saved as a file in its original streaming format, which is normally not playable as a regular video file. VLC manages to play this file, but most other players don't. So I need to convert it to a regular video file. I am currently investigating whether I can do this with ffmpeg if I provide it with an SDP file for the recorded stream. All help is welcome!

    Read the article

  • Game login authentication and security.

    - by Charles
    First off I will say I am completely new to security in coding. I am currently helping a friend develop a small game (in Python) which will have a login server. I don't have much knowledge regarding security, but I know many games do have issues with this. Everything from 3rd party applications (bots) to WPE packet manipulation. Considering how small this game will be and the limited user base, I doubt we will have serious issues, but would like to try our best to limit problems. I am not sure where to start or what methods I should use, or what's worth it. For example, sending data to the server such as login name and password. I was told his information should be encrypted when sending, so in-case someone was viewing it (with whatever means), that they couldn't get into the account. However, if someone is able to capture the encrypted string, wouldn't this string always work since it's decrypted server side? In other words, someone could just capture the packet, reuse it, and still gain access to the account? The main goal I am really looking for is to make sure the players are logging into the game with the client we provide, and to make sure it's 'secure' (broad, I know). I have looked around at different methods such as Public and Private Key encryption, which I am sure any hex editor could eventually find. There are many other methods that seem way over my head at the moment and leave the impression of overkill. I realize nothing is 100% secure. I am just looking for any input or reading material (links) to accomplish the main goal stated above. Would appreciate any help, thanks.

    Read the article

  • asynchronous pages

    - by lockedscope
    I have just read the multi-threading and custom threading in asp.net articles. http://www.williablog.net/williablog/post/2008/12/16/Custom-Threading-in-ASPNET.aspx http://www.williablog.net/williablog/post/2008/12/16/Multi-Threading-in-ASPNET.aspx I have couple of questions. What does he mean by returning a thread to the pool? Is that thread completely removed from memory or put in to a state that it does not scheduled to CPU(is it in sleep state or whatever)? If that thread is removed from memory how could it survive after async point? How this mechanism works? Are every objects(pages class, request,response etc.) are copied to somewhere else before they are disposed? (Or, is it just waiting in a sleep state and then its waked when async call ends?) He is saying that; "Having said that, making pages asynchronous is not really about improving performance, it is about improving scalability" then he is saying; "I'm sorry to say that it will do nothing for scalability or performance." So which one is true? or for which case(s) are they true?

    Read the article

  • How do I avoid repetition in Java ResourceBundle strings?

    - by Trejkaz
    We had a lot of strings which contained the same sub-string, from sentences about checking the log or how to contact support, to branding-like strings containing the company or product name. The repetition was causing a few issues for ourselves (primarily typos or copy/paste errors) but it also causes issues in that it increases the amount of text our translator has to translate. The solution I came up with went something like this: public class ExpandingResourceBundleControl extends ResourceBundle.Control { public static final ResourceBundle.Control EXPANDING = new ExpandingResourceBundleControl(); private ExpandingResourceBundleControl() { } @Override public ResourceBundle newBundle(String baseName, Locale locale, String format, ClassLoader loader, boolean reload) throws IllegalAccessException, InstantiationException, IOException { ResourceBundle inner = super.newBundle(baseName, locale, format, loader, reload); return inner == null ? null : new ExpandingResourceBundle(inner, loader); } } ExpandingResourceBundle delegates to the real resource bundle but performs conversion of {{this.kind.of.thing}} to look up the key in the resources. Every time you want to get one of these, you have to go: ResourceBundle.getBundle("com/acme/app/Bundle", EXPANDING); And this works fine -- for a while. What eventually happens is that some new code (in our case autogenerated code which was spat out of Matisse) looks up the same resource bundle without specifying the custom control. This appears to be non-reproducible if you write a simple unit test which calls it with and then without, but it occurs when the application is run for real. Somehow the cache inside ResourceBundle ejects the good value and replaces it with the broken one. I am yet to figure out why and Sun's jar files were compiled without debug info so debugging it is a chore. My questions: Is there some way of globally setting the default ResourceBundle.Control that I might not be aware of? That would solve everything rather elegantly. Is there some other way of handling this kind of thing elegantly, perhaps without tampering with the ResourceBundle classes at all?

    Read the article

  • Google Code Jam 2010 Large DataSets Take Too Long to Submit

    - by Travis
    Hey Guys, I'm participating in the 2010 code jam and I solved two of the problems for the small data sets, but I'm not even close to solving the large data sets in the 8 minute time frame. I'm wondering if anyone out there has solved the large data set: What hardware were you running on? What language were you running on? What performance tuning techniques did you do on your code to run as fast as possible? I'm writing the solutions in Ruby, which is not my day to day language, and executing them on my Macbook Pro. My solutions for problem A and problem C are on github at http://github.com/tjboudreaux/codejam2010. I'd appreciate any suggestions that you may have. FWIW, I have alot of experience in C++ from college, my primary language is PHP, and my "sandbox" language is Ruby. Was I just a bit ambitious by taking a shot at this in Ruby, not knowing where the language struggles for performance, or does anyone see anything that's a redflag as to why I can't complete the large dataset in time to submit.

    Read the article

  • Replicating SQL's 'Join' in Python

    - by Daniel Mathews
    I'm in the process of trying to switch from R to Python (mainly issues around general flexibility). With Numpy, matplotlib and ipython, I've am able to cover all my use cases save for merging 'datasets'. I would like to simulate SQL's join by clause (inner, outer, full) purely in python. R handles this with the 'merge' function. I've tried the numpy.lib.recfunctions join_by, but it critical issues with duplicates along the 'key': join_by(key, r1, r2, jointype='inner', r1postfix='1', r2postfix='2', defaults=None, usemask=True, asrecarray=False) Join arrays r1 and r2 on key key. The key should be either a string or a sequence of string corresponding to the fields used to join the array. An exception is raised if the key field cannot be found in the two input arrays. Neither r1 nor r2 should have any duplicates along key: the presence of duplicates will make the output quite unreliable. Note that duplicates are not looked for by the algorithm. source: http://presbrey.mit.edu:1234/numpy.lib.recfunctions.html Any pointers or help will be most appreciated!

    Read the article

  • Does anyone know of a good Commercial WPF Web Browser Control?

    - by VoidDweller
    I have an MDI WPF app that I need to add web content too. At first, great it looks like I have 2 options built into the framework the Frame control and the WebBrowser control. Given that this is an MDI app it doesn't take long to discover that neither of these will work. The WebBrowser control wraps up the IE WebBrowser ActiveX Control which uses the Win32 graphics pipeline. The "Airspace" issue pretty much sums this up as "Sorry, the layouts will not play nice together". Yes, I have thought about taking snapshots of the web content rendering these and mapping the mouse and keyboard events back to the browser control, but I can't afford the performance penalty and I really don't have time to write and thoroughly test it. I have looked for third party controls, but so far I have only found Chris Cavanagh's WPF Chromium Web Browser control. Which wraps up Awesomium 1.5. Together these are very cool, they play nice with the WPF layouts. But they do not meet my performance requirements. They are VERY HEAVY on memory consumption and not to friendly with CPU usage either. Not to mention still quite buggy. I'll elaborate if you are interested. So, do any of you know of a stable performant WPF web browser control? Thanks.

    Read the article

  • "Replay" the steps needed to recreate an error

    - by David
    I am going to create a typical business application that will be used by a few hundred consultants. Normally, the consultants would be presented with an error message with a standard text. As the application will be a complicated one with lots of changes being made to it constantly I would like the following: When an error message is presented, the user has the option to "send" the error message to the developers. The developers should be able to open the incoming file in i.e. Eclipse and debug the steps of the last 10 minutes of work step by step (one line at a time if they want to). Everything should be transparent, meaning that they for example should be able to see the return values of calls to the database. Are there any solutions that offer such functionality today, my preferred language is Python or also Java. I know that there will be a huge performance hit because of such functionality, but that is acceptable as this kind of software is not performance sensitive. It would be VERY nice if the database also had a cronology so that one could query the database for values that existed at the exact time that a specific line of code was run in the application, leading up to the bug.

    Read the article

  • How to use references, avoid header bloat, and delay initialization?

    - by Kyle
    I was browsing for an alternative to using so many shared_ptrs, and found an excellent reply in a comment section: Do you really need shared ownership? If you stop and think for a few minutes, I'm sure you can pinpoint one owner of the object, and a number of users of it, that will only ever use it during the owner's lifetime. So simply make it a local/member object of the owners, and pass references to those who need to use it. I would love to do this, but the problem becomes that the definition of the owning object now needs the owned object to be fully defined first. For example, say I have the following in FooManager.h: class Foo; class FooManager { shared_ptr<Foo> foo; shared_ptr<Foo> getFoo() { return foo; } }; Now, taking the advice above, FooManager.h becomes: #include "Foo.h" class FooManager { Foo foo; Foo& getFoo() { return foo; } }; I have two issues with this. First, FooManager.h is no longer lightweight. Every cpp file that includes it now needs to compile Foo.h as well. Second, I no longer get to choose when foo is initialized. It must be initialized simultaneously with FooManager. How do I get around these issues?

    Read the article

  • PostgreSQL: BYTEA vs OID+Large Object?

    - by mlaverd
    I started an application with Hibernate 3.2 and PostgreSQL 8.4. I have some byte[] fields that were mapped as @Basic (= PG bytea) and others that got mapped as @Lob (=PG Large Object). Why the inconsistency? Because I was a Hibernate noob. Now, those fields are max 4 Kb (but average is 2-3 kb). The PostgreSQL documentation mentioned that the LOs are good when the fields are big, but I didn't see what 'big' meant. I have upgraded to PostgreSQL 9.0 with Hibernate 3.6 and I was stuck to change the annotation to @Type(type="org.hibernate.type.PrimitiveByteArrayBlobType"). This bug has brought forward a potential compatibility issue, and I eventually found out that Large Objects are a pain to deal with, compared to a normal field. So I am thinking of changing all of it to bytea. But I am concerned that bytea fields are encoded in Hex, so there is some overhead in encoding and decoding, and this would hurt the performance. Are there good benchmarks about the performance of both of these? Anybody has made the switch and saw a difference?

    Read the article

  • Cassandra random read speed

    - by Jody Powlette
    We're still evaluating Cassandra for our data store. As a very simple test, I inserted a value for 4 columns into the Keyspace1/Standard1 column family on my local machine amounting to about 100 bytes of data. Then I read it back as fast as I could by row key. I can read it back at 160,000/second. Great. Then I put in a million similar records all with keys in the form of X.Y where X in (1..10) and Y in (1..100,000) and I queried for a random record. Performance fell to 26,000 queries per second. This is still well above the number of queries we need to support (about 1,500/sec) Finally I put ten million records in from 1.1 up through 10.1000000 and randomly queried for one of the 10 million records. Performance is abysmal at 60 queries per second and my disk is thrashing around like crazy. I also verified that if I ask for a subset of the data, say the 1,000 records between 3,000,000 and 3,001,000, it returns slowly at first and then as they cache, it speeds right up to 20,000 queries per second and my disk stops going crazy. I've read all over that people are storing billions of records in Cassandra and fetching them at 5-6k per second, but I can't get anywhere near that with only 10mil records. Any idea what I'm doing wrong? Is there some setting I need to change from the defaults? I'm on an overclocked Core i7 box with 6gigs of ram so I don't think it's the machine. Here's my code to fetch records which I'm spawning into 8 threads to ask for one value from one column via row key: ColumnPath cp = new ColumnPath(); cp.Column_family = "Standard1"; cp.Column = utf8Encoding.GetBytes("site"); string key = (1+sRand.Next(9)) + "." + (1+sRand.Next(1000000)); ColumnOrSuperColumn logline = client.get("Keyspace1", key, cp, ConsistencyLevel.ONE); Thanks for any insights

    Read the article

  • Daemon program that uses select() inside infinite loop uses significantly more CPU when ported from

    - by Jake
    I have a daemon app written in C and is currently running with no known issues on a Solaris 10 machine. I am in the process of porting it over to Linux. I have had to make minimal changes. During testing it passes all test cases. There are no issues with its functionality. However, when I view its CPU usage when 'idle' on my Solaris machine it is using around .03% CPU. On the Virtual Machine running Red Hat Enterprise Linux 4.8 that same process uses all available CPU (usually somewhere in the 90%+ range). My first thought was that something must be wrong with the event loop. The event loop is an infinite loop ( while(1) ) with a call to select(). The timeval is setup so that timeval.tv_sec = 0 and timeval.tv_usec = 1000. This seems reasonable enough for what the process is doing. As a test I bumped the timeval.tv_sec to 1. Even after doing that I saw the same issue. Is there something I am missing about how select works on Linux vs. Unix? Or does it work differently with and OS running on a Virtual Machine? Or maybe there is something else I am missing entirely? One more thing I am sure sure which version of vmware server is being used. It was just updated about a month ago though. Thanks.

    Read the article

< Previous Page | 376 377 378 379 380 381 382 383 384 385 386 387  | Next Page >