Search Results

Search found 17526 results on 702 pages for 'dynamic methods'.

Page 341/702 | < Previous Page | 337 338 339 340 341 342 343 344 345 346 347 348  | Next Page >

  • Implementing a robust async stream reader for a console

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

    Read the article

  • Convert SQL server datetime fields to compare date parts only, with indexed lookups

    - by Caveatrob
    I've been doing a convert(varchar,datefield,112) on each date field that I'm using in 'between' queries in SQL server to ensure that I'm only accounting for dates and not missing any based on the time part of datetime fields. Now, I'm hearing that the converts aren't indexable and that there are better methods, in SQL Server 2005, to compare the date part of datetimes in a query to determine if dates fall in a range. What is the optimal, indexable, method of doing something like this: select * from appointments where appointmentDate='08-01-2008' and appointmentDate<'08-15-2008'

    Read the article

  • How to 'do' ByVal in C#

    - by Jouke van der Maas
    As I understand it, C# passes parameters into methods by reference. In vb.net, you can specify this with ByVal and ByRef. The default is ByVal. Is this for compatibility with vb6, or is it just random? Also, how can I specify what to use in C#? I kind of like the idea of passing parameters by value.

    Read the article

  • C# - Programmatically Log-off and Log-on a user

    - by Nullstr1ng
    Hi, I'd like to know if is there any way in C# to programatically log-in a Windows User Account? We are currently developing an monitoring application and one of the feature is to be able to log-off the current Windows User and switch to another Windows User Account. I have some few methods for Logging off, such as through API or Command Line. But what about logging-in a user account?

    Read the article

  • Error while setting up Anywhere Access on Windows Server 2012 Essential (personalized domain name from Microsoft)

    - by Thomas
    I am trying to setup Anywhere Access on a Windows Server 2012 Essential Release Candidate, but keep getting this error: "The domain name was not setup for your server. Wait a few minutes and run the wizard again. An unknown error occurred. Please wait a few minutes and then try again". These are the options that I selected in the Wizard: I want to set up a new domain name Get a personalized domain name from Microsoft Entered my Windows live id and password xxxx.remotewebaccess.com And on the next page the error is displayed. I have setup my router (Linksys WRT160N) to forward all TCP traffic to the Server. UPnP is also enabled. If I hit my public (dynamic) IP (http://188.182.194.182/) I get the Windows Server 2012 homepage. Any ideas?

    Read the article

  • Get length of bits used in int

    - by sigvardsen
    If you have the binary number 10110 how can I get it to return 11111? e.g a new binary number that sets all bits to 1 after the first 1, there are some likewise examples listed below: 101 should return 111 (3 bit length) 011 should return 11 (2 bit length) 11100 should be return 11111 (5 bit length) 101010101 should return 111111111 (9 bit length) How can this be obtained the easiest way in Java? I could come up with some methods but they are not very "pretty".

    Read the article

  • Permission forbidden on localhost with apache2

    - by N Alex
    Here is what I am trying to do. I tried to add another folder to apache and I get the following error when trying to acces testing/index.html. The idea is that I would like to have for every customer a folder like /home/neagoe/Work/InterWebs/Projects/[PROJECT NAME]/CustomerProjects/website/dist. Forbidden You don't have permission to access /index.html on this server. Apache/2.2.22 (Ubuntu) Server at testing Port 80 Here are the steps that I followed: Step1: sudo chmod a+x /home/neagoe/Work/InterWebs/Projects/testing/CustomerProjects/website/dist Step2: sudo chown -R www-data:www-data /home/neagoe/Work/InterWebs/Projects/testing/CustomerProjects/website/dist sudo chmod -R 775 /home/neagoe/Work/InterWebs/Projects/testing/CustomerProjects/website/dist Step3: sudo adduser $USER www-data Step4: sudo a2enmod userdir Step5: sudo cp /etc/apache/sites-available/default /etc/apache/sites-available/testing I edited the file /etc/apache/sites-available/testing so it looks like this: <VirtualHost *:80> ServerAdmin webmaster@localhost ServerName testing DocumentRoot /home/neagoe/Work/InterWebs/Projects/testing/CustomerProjects/website/dist <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /home/neagoe/Work/InterWebs/Projects/testing/CustomerProjects/website/dist/ > Options Indexes FollowSymLinks MultiViews AllowOverride All Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/access.log combined </VirtualHost> Step6: I edited hosts ("/etc/hosts") so it looks like this: 127.0.0.1 localhost 127.0.0.1 testing # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters Step7: sudo a2ensite testing sudo service apache2 restart I searched for about 2 hours on the internet but I can't figure out what went wrong. All the pages that I found following the same steps as described above. I know there are similar questions here on the internet, but the answer is to change permission to the directory which I did on Step2. I am sorry if this is really a duplicate but I could't find the right answer. Thank you! PS. I asked this also on AskUbuntu but didn't get any answers so I'm trying my luck here. Edit: There isn't much on the error log or the access log. On the access.log: ::1 - - [10/Aug/2013:11:23:28 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:29 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:31 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:32 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:33 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:34 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:35 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" 127.0.0.1 - - [10/Aug/2013:11:23:23 +0300] "POST /wordpress-testing/wp-cron.php?doing_wp_cron=1376123003.7026669979095458984375 HTTP/1.0" 200 705 "-" "WordPress/3.6; http://localhost/wordpress-testing" ::1 - - [10/Aug/2013:11:23:36 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:37 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" ::1 - - [10/Aug/2013:11:23:38 +0300] "OPTIONS * HTTP/1.0" 200 126 "-" "Apache/2.2.22 (Ubuntu) (internal dummy connection)" 127.0.0.1 - - [10/Aug/2013:11:31:32 +0300] "GET /index.html HTTP/1.1" 200 485 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:23.0) Gecko/20100101 Firefox/23.0" And the last line repeats for about 200 rows. On the error.log: 1. This lines repeat from time to time. PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php5/20100525 /msql.so' - /usr/lib/php5/20100525/msql.so: cannot open shared object file: No such file or directory in Unknown on line 0 [Sat Aug 10 13:06:42 2013] [notice] Apache/2.2.22 (Ubuntu) PHP/5.4.9-4ubuntu2.2 configured -- resuming normal operations [Sat Aug 10 13:07:36 2013] [notice] caught SIGTERM, shutting down PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php5/20100525/msql.so' - /usr/lib/php5/20100525/msql.so: cannot open shared object file: No such file or directory in Unknown on line 0 [Sat Aug 10 13:07:37 2013] [notice] Apache/2.2.22 (Ubuntu) PHP/5.4.9-4ubuntu2.2 configured -- resuming normal operations 2. And this is the predominant error. (hundreds of lines) [Sat Aug 10 13:07:40 2013] [error] [client 127.0.0.1] (13)Permission denied: access to /index.html denied

    Read the article

  • Is there a simple way to emulate friendship in php 5.3

    - by Itay Moav
    I need some classes to befriend other classes in my system. Lack of this feature made me publicize some methods which shouldn't be public. The consequences of that are that members of my team implement code in a bad and ugly way which causes a mess. Is there a way to define a friendship in php 5.3? (I am aware of http://bugs.php.net/bug.php?id=34044 You might want to vote there if there is no simple solution).

    Read the article

  • Documenting PHP multiple inheritance with PhpDoc

    - by Sam Dark
    I have multiple inheritance like this one: http://stackoverflow.com/questions/356128/can-i-extend-a-class-using-more-than-1-class-in-php (let's not discuss this approach itself please) and want my IDE to know about inherited class methods and properties. Is there a way to do it with PhpDoc?

    Read the article

  • How to set the Windows Mobile 6 IME mode (to numbers only)

    - by Daniel Crenna
    In Windows Mobile 5 one of the following methods works to set an input to numbers only: // Managed InputModeEditor.SetInputMode(textBox, InputMode.Numeric); // Native Wrapper InputModeSupport.SHSetImeMode(textBox.Handle, InputModeSupport.SHIME_MODE.SHIME_MODE_NUMBERS); In Windows Mobile 6, neither works. How do you set the IME to "Numbers Only" in WM 6.0 / .NET CF 3.5?

    Read the article

  • iis 7.0 output caching

    - by george9170
    My company is serving up deep-zoom maps. We have 100'000s jpg images being served up and was wondering if output caching would be the way to go. Our problem is latency on serving the images. I was wondering if i output caching would indeed improve latency and a general explanation about output caching. I have visisted http://blogs.iis.net/bills/archive/2007/05/02/iis7-output-caching-for-dynamic-content-dramatically-speed-up-your-asp-and-php-applications.aspx and was wondering if there are any other good sites to look at. thank you very much.

    Read the article

  • ASP.NET MVC security: how to check if a controller method is allowed to execute under current user's

    - by Gart
    Given an ASP.NET MVC Controller class declaration: public class ItemController : Controller { public ActionResult Index() { // ... } public ActionResult Details() { // ... } [Authorize(Roles="Admin, Editor")] public ActionResult Edit() { // ... } [Authorized(Roles="Admin")] public ActionResult Delete() { // .. } } I need to reflect a list of methods in this class which may be invoked with the current user's permissions. Please share some ideas of what could be done in this case.

    Read the article

  • Unmodifiable NavigableSet/NavigableMap in Java?

    - by Greg Mattes
    java.util.Collections has several unmodifiable methods that provide unmodifiable collection views by wrapping collections in decorators that prohibit mutation operations. Java 6 added support for java.util.NavigableSet and java.util.NavigableMap. I'd like to be able to have unmodifiable NavigableSets and NavigableMaps, but java.util.Collections#unmodifiableSortedSet(SortedSet) and java.util.Collections#unmodifiableSortedMap(SortedMap) are not sufficient because they do not support the operations that are particular to NavigableSet and NavigableMap. Are there de-facto implementations for unmodifiableNavigableSet and unmodifiableNavigableMap?

    Read the article

  • Find Tables in PDF's

    - by nWorx
    Hello, Are there any tools or tricks how to automatically extract tables from pdfs. Are there any C# libraries that could do that? Or do you maybe know other methods how this could be handled? Thank you very much

    Read the article

  • C# Creating A Error Checking Class?

    - by Soo
    Hi StackOverflow, I'm very new to OOP, and in the program I'm working on, I have an Utilities class that contains some general methods. Should I include my error checking in the Utilities class or should I create a new class just for error checking?

    Read the article

  • Exchange mail users cannot send to certain lists

    - by blsub6
    First of all, everyone's on Exchange 2010 using OWA I have a dynamic distribution list that contains all users in my domain called 'staff'. I can send to this list, other people can send to this list, but I have one user that cannot send to this list. Sending to this list gives the user an email back with the error: Delivery has failed to these recipients or groups: Staff The e-mail address you entered couldn't be found. Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk. and then a bunch of diagnostic information that I don't want to paste here because I don't want to have to censor all of the sensitive information contained (lazy) Can you guys throw me some possible reasons why this would happen? If there are an innumerable number of reasons, where should I start to troubleshoot this? EDIT One Exchange server inside the network that acts as a transport server, client access server and mailbox server and one Edge Transport server in the DMZ.

    Read the article

  • Processing image data in java me

    - by Trimack
    Hi, I want to process raw data from a picture taken in java me with byte[] snap = videoControl.getSnapshot(encoding); My question is, whether I should try working already with snap or should I first create the image from this array Image im = Image.createImage(snap, 0, snap.length); and then work with that? Or is there some better documentation of both methods, i.e. getSnapshot and createImage than the Java API reference?

    Read the article

  • php date() function displaying wrong time

    - by ladaghini
    I'm building a site with wordpress, and when I use the date() function on an otherwise empty file, it shows the right date. However, if I use it in a file that includes other wordpress files, the time is displayed as GMT time, so the date is off. If anyone can figure out how I can use date function without interruption from the wordpress methods, I'd appreciated it.

    Read the article

  • What's faster Model.get(keys) or Model.get_by_id(ids, parent=None)

    - by WooYek
    I'm wondering is there a difference in terms of computing cost for the Model.get(keys) and Model.get_by_id(ids, parent=None) methods? Is there a server side computing advantage of using numeric id's over encoded string keys, or other way around? How big is the difference? PS. Sorry, if it's a dupe. I'm sure I read an article about it, but I cannot find it now.

    Read the article

  • Reimplementing data structures in the real world

    - by Jason
    The topic of algorithms class today was reimplementing data structures, specifically ArrayList in Java. The fact that you can customize a structure for in various ways definitely got me interested, particularly with variations of add() & iterator.remove() methods. But is reimplementing and customizing a data structure something that is of more interest to the academics vs the real-world programmers? Has anyone reimplemented their own version of a data structure in a commercial application/program, and why did you pick that route over your particular language's implementation?

    Read the article

  • Can you reverse order a string in one line with LINQ or a LAMBDA expression

    - by Student for Life
    Not that I would want to use this practically (for many reasons) but out of strict curiousity I would like to know if there is a way to reverse order a string using LINQ and/or LAMBDA expressions in one line of code, without utilising any framework "Reverse" methods. e.g. string value = "reverse me"; string reversedValue = (....); and reversedValue will result in "em esrever" EDIT Clearly an impractical problem/solution I know this, so don't worry it's strictly a curiosity question around the LINQ/LAMBDA construct.

    Read the article

< Previous Page | 337 338 339 340 341 342 343 344 345 346 347 348  | Next Page >