Search Results

Search found 7338 results on 294 pages for 'useful'.

Page 51/294 | < Previous Page | 47 48 49 50 51 52 53 54 55 56 57 58  | Next Page >

• Move over DFS and Robocopy, here is SyncToy!

  - by andywe

  Ever since Windows 2000, I have always had the need to replicate data to multiple endpoints with the same content. Until DFS was introduced, the method of thinking was to either manually copy the data location by location, or to batch script it with xcopy and schedule a task. Even though this worked (and still does today), it was cumbersome, and intensive on the network, especially when dealing with larger amounts of data. Then along came robocopy, as an internal tool written by an enterprising programmer at Microsoft. We used it quite a bit, especially when we could not use DFS in the early days. It was received so well, it made it into the public realm. At least now we could have the ability to determine what files had changed and only replicate those. Well, over time there has been evolution of this ideal. DFS is obviously the Windows enterprise class service to do this, along with BrancheCache..however you don’t always need or want the power of DFS, especially when it comes to small datacenter installations, or remote offices. I have specific data sets that are on closed or restricted networks, that either have a security need for this, or are in remote countries where bandwidth is a premium. FOr this, I use the latest evolution for one off replication names Synctoy. Synctoy is from Microsoft, seemingly released in 2009, that wraps a nice GUI around setting up a paired set of folders (remember the mobile briefcase from Windows 98?), and allowing you the choice of synchronization methods. 1 way, or 2 way. Simply create a paired set of folders on the source and destination, choose your options for content, exclude any file types you don’t want to replicate, and click run. Scheduling is even easier. MS has included a wrapper for doing just this so all you enter in your task schedule in the SynToyCMD.exe, a –R as an argument, and the time schedule. No more complicated command lines or scripts.   I find this especially useful when I use MS backup to back up a system volume, but only want subsets of backup information of a data share and ONLY when that dataset has changed. Not relying on full backups and incremental. An example of this is my application installation master share. I back this up with SyncToy because I do not need multiple backup copies..one copy elsewhere suffices to back it up. At home, very useful for your pictures, videos, music, ect..the backup is online and ready to access, not waiting for you to restore a backup file, and no need to institute a domain simply to have DFS.'   Do note there is a risk..if you accidently delete a file and do not catch this before the next sync, then depending on your SyncToy settings, you can indeed lose that file as the destination updates..so due diligence applies. I make it a rule to sync manly one way…I use my master share for making changes, and allow the schedule to follow suit. Any real important file I lock down as read only through file permissions so it cannot be deleted unless I intervene.   Check out the tool and have some fun! http://www.microsoft.com/en-us/download/details.aspx?DisplayLang=en&id=15155

  Read the article

• What Counts For a DBA – Depth

  - by Louis Davidson

  SQL Server offers very simple interfaces to many of its features. Most people could open up SSMS, connect to a server, write a simple query and see the results. Even several of the core DBA tasks are deceptively straightforward. It doesn’t take a rocket scientist to perform a basic database backup or run a trace (even using the newfangled Extended Events!). However, appearances can be deceptive, and often times it is really important that a DBA understands not just the basics of how to perform a task, but why we do a task, and how that task works. As an analogy, consider a child walking into a darkened room. Most would know that they need to turn on the light, and how to do it, so they flick the switch. But what happens if light fails to shine forth. Most would immediately tell you that you need to consider changing the light bulb. So you hop in the car and take them to the local home store and instruct them to buy a replacement. Confronted with a 40 foot display of light bulbs, how will they decide which of the hundreds of types of bulbs, of different types, fittings, shapes, colors, power and efficiency ratings, is the right choice? Obviously the main lesson the child is going to learn this day is how to use their cell phone as a flashlight so they don’t have to ask for help the next time. Likewise, when the metaphorical toddlers who use your database server have issues, they will instinctively know something is wrong, and may even have some idea what caused it, but will have no depth of knowledge to figure out the right solution. That is where the DBA comes in and attempts to save the day. However, when one looks beneath the shiny UI, SQL Server has its own “40 foot display of light bulbs”, in the form of the tremendous number of tools and the often-bewildering amount of information they can present to the DBA, to help us find issues. Unfortunately, resorting to guesswork, to trying different “bulbs” over and over, hoping to stumble on the answer. This is where the right depth of knowledge goes a long way. If we need to write a SELECT statement, then knowing the syntax and where to find the data is not enough. Knowledge of indexes and query plans is essential. Without it, we might hit on a query that “works”, but we are basically still a user, not a programmer, because we have no real control over our platform. Is that level of knowledge deep enough? Probably not, since knowledge of the underlying metadata and structures would be very useful in helping us make sense of any query plan. Understanding the structure of an index makes the “key lookup” operator not sound like what you do when someone tapes your car key to the ceiling. So is even this level of understanding deep enough? Do we need to understand the memory architecture used to process the query? It might be a comforting level of knowledge, and will doubtless come in handy at some point, but is not strictly necessary in most cases. Beyond that lies (more or less) full knowledge of SQL language and the intricacies of every step the SQL Server engine takes to process our query. My personal theory is that, as a professional, our knowledge of a given task should extend, at a minimum, one level deeper than is strictly necessary to perform the task. Anything deeper can be left to the ridiculously smart, or obsessive, or both. As an example. tasked with storing an integer value between 0 and 99999999, it’s essential that I know that choosing an Integer over Decimal(8,0) will likely offer performance benefits. It is then useful that I also understand the value of adding a CHECK constraint, to make sure the values are valid to the desired range; and comforting that I know a little about the underlying processors, registers and computer math. Anything further, I leave to the likes of Joe Chang, whose recent blog post on the topic offers depth by the bucketful!  

  Read the article

• Hopping/Tumbling Windows Could Introduce Latency.

  This is a pre-article to one I am going to be writing on adjusting an event’s time and duration to satisfy business process requirements but it is one that I think is really useful when understanding the way that Hopping/Tumbling windows work within StreamInsight.  A Tumbling window is just a special shortcut version of  a Hopping window where the width of the window is equal to the size of the hop Here is the simplest and often used definition for a Hopping Window.  You can find them all here public static CepWindowStream<CepWindow<TPayload>> HoppingWindow<TPayload>(     this CepStream<TPayload> source,     TimeSpan windowSize,     TimeSpan hopSize,     WindowInputPolicy inputPolicy,     HoppingWindowOutputPolicy outputPolicy )   And here is the definition for a Tumbling Window public static CepWindowStream<CepWindow<TPayload>> TumblingWindow<TPayload>(     this CepStream<TPayload> source,     TimeSpan windowSize,     WindowInputPolicy inputPolicy,     HoppingWindowOutputPolicy outputPolicy )   These methods allow you to group events into windows of a temporal size.  It is a really useful and simple feature in StreamInsight.  One of the downsides though is that the windows cannot be flushed until an event in a following window occurs.  This means that you will potentially never see some events or see them with a delay.  Let me explain. Remember that a stream is a potentially unbounded sequence of events. Events in StreamInsight are given a StartTime.  It is this StartTime that is used to calculate into which temporal window an event falls.  It is best practice to assign a timestamp from the source system and not one from the system clock on the processing server.  StreamInsight cannot know when a window is over.  It cannot tell whether you have received all events in the window or whether some events have been delayed which means that StreamInsight cannot flush the stream for you.   Imagine you have events with the following Timestamps 12:10:10 PM 12:10:20 PM 12:10:35 PM 12:10:45 PM 11:59:59 PM And imagine that you have defined a 1 minute Tumbling Window over this stream using the following syntax var HoppingStream = from shift in inputStream.TumblingWindow(TimeSpan.FromMinutes(1),HoppingWindowOutputPolicy.ClipToWindowEnd) select new WindowCountPayload { CountInWindow = (Int32)shift.Count() };   The events between 12:10:10 PM and 12:10:45 PM will not be seen until the event at 11:59:59 PM arrives.  This could be a real problem if you need to react to windows promptly This can always be worked around by using a different design pattern but a lot of the examples I see assume there is a constant, very frequent stream of events resulting in windows always being flushed. Further examples of using windowing in StreamInsight can be found here

  Read the article

• Web Service Example - Part 3: Asynchronous

  - by Denis T

  In this edition of the ADF Mobile blog we'll tackle part 3 of our Web Service examples.  In this posting we'll take a look at firing the web service asynchronously and then filling in the UI when it completes.  This can be useful when you have data on the device in a local store and want to show that to the user while the application uses lazy loading from a web service to load more data. Getting the sample code: Just click here to download a zip of the entire project.  You can unzip it and load it into JDeveloper and deploy it either to iOS or Android.  Please follow the previous blog posts if you need help getting JDeveloper or ADF Mobile installed.  Note: This is a different workspace than WS-Part2 What's different? In this example, when you click the Search button on the Forecast By Zip option, now it takes you directly to the results page, which is initially blank.  When the web service returns a second or two later the data pops into the UI.  If you go back to the search page and hit Search it will again clear the results and invoke the web service asynchronously.  This isn't really that useful for this particular example but it shows an important technique that can be used for other use cases. How it was done 1)  First we created a new class, ForecastWorker, that implements the Runnable interface.  This is used as our worker class that we create an instance of and pass to a new thread that we create when the Search button is pressed inside the retrieveForecast actionListener handler.  Once the thread is started, the retrieveForecast returns immediately.  2)  The rest of the code that we had previously in the retrieveForecast method has now been moved to the retrieveForecastAsync.  Note that we've also added synchronized specifiers on both these methods so they are protected from re-entrancy. 3)  The run method of the ForecastWorker class then calls the retrieveForecastAsync method.  This executes the web service code that we had previously, but now on a separate thread so the UI is not locked.  If we had already shown data on the screen it would have appeared before this was invoked.  Note that you do not see a loading indicator either because this is on a separate thread and nothing is blocked. 4)  The last but very important aspect of this method is that once we update data in the collections from the data we retrieve from the web service, we call AdfmfJavaUtilities.flushDataChangeEvents().   We need this because as data is updated in the background thread, those data change events are not propagated to the main thread until you explicitly flush them.  As soon as you do this, the UI will get updated if any changes have been queued. Summary of Fundamental Changes In This Application The most fundamental change is that we are invoking and handling our web services in a background thread and updating the UI when the data returns.  This allows an application to provide a better user experience in many cases because data that is already available locally is displayed while lengthy queries or web service calls can be done in the background and the UI updated when they return.  There are many different use cases for background threads and this is just one example of optimizing the user experience and generating a better mobile application. 

  Read the article

• Tutorials and libraries for OpenGL-ES games on Android

  - by user197141

  What tutorials and libraries are available which can help beginners to develop 2D and 3D games on Android using OpenGL-ES? I'm looking for tutorials which can help me learn OpenGL-ES, and I'm looking for OpenGL-ES libraries which can make life easier for beginners in OpenGL-ES. Since Android is still small, I guess it may be help-full to read iPhone OpenGL-ES tutorials as well, as I suppose the OpenGL-ES functionality is much the same. I have found the following useful information which I would have liked to share: Android tutorials: Basic tutorial covering polygons, no textures anddev forum with some tutorials Other Android OpenGL-ES information: Google IO lecture regarding games, not much OpenGLES The The Khronos Reference Manual is also relevant to have, but its not exactly the best place to start. iPhone OpenGL-ES tutorials (where the OpenGl-ES information is probably useful): http://web.me.com/smaurice/AppleCoder/iPhone_OpenGL/Archive.html http://iphonedevelopment.blogspot.com/2009/05/opengl-es-from-ground-up-table-of.html As for libraries which a beginner might use to get a simpler hands-on experience with OpenGL-ES, I have only found Rokon, which is recently started, thus has many holes and bugs. And it's gnuGPL licensed (at the moment) which means it cannot be used, if we wish to sell our games. What else is out there?

  Read the article

• Can somebody explain the differences, status and future of the various ASP.NET AJAX libraries and to

  - by tjrobinson

  I'm confused about the differences and relationships between the various Microsoft ASP.NET AJAX components/libraries/toolkits and particularly the naming of them. It starts off relatively simple with ASP.NET AJAX itself: ASP.NET AJAX 1.0 (available for ASP.NET 2.0 in a separate package called ASP.NET 1.0 Extensions) ASP.NET AJAX 3.5 (included with ASP.NET 3.5) ASP.NET AJAX 4.0 (included with ASP.NET 4.0) Then come the various projects on CodePlex and elsewhere: ASP.NET AJAX Control Toolkit (aka Original Ajax Control Toolkit) Samples CodePlex It seems that the September 2009 Release is the final release of the Original Ajax Control Toolkit and that it's been superseded by... Ajax Control Toolkit in ASP.NET Ajax Library It looks like the old ASP.NET AJAX Control Toolkit has now become part of a larger ASP.NET Ajax Library but is still maintained seperately on CodePlex. This release is in beta at time of writing so presumably if I want to use the "Control Toolkit" I should stick with the September 2009 Release of the Original ASP.NET AJAX Control Toolkit CodePlex Microsoft Ajax Library Preview Is this the same as the ASP.NET Ajax Library mentioned above just with a confusing name variation? Is the "Control Toolkit" included in Preview 6 and is it older newer or older than the code in Ajax Control Toolkit in ASP.NET Ajax Library? CodePlex Microsoft ASP.NET Ajax Wiki - note the inconsistent insertion of ASP.NET into the name Links to useful articles, roadmaps would be useful.

  Read the article

• How To Create Your Own x86 Operating System for Modern PC Computers

  - by mudge

  I'd like to create a new operating system for x86 PC computers. I'd like it to be 64-bit but possibly run as 32-bit as well. I have these kinds of questions: What kinds of things do you start working on first? Knowing where to start in writing your own operating system seems to me to be a tricky subject, so I am interested in your input. Generally how to go about making your own 32-bit/64-bit operating system, or good resources that mention useful information about going about writing your own operating system for x86 computers. I don't care how old sources are as long as they are still relevant and useful to what I am doing. I know that I will want it to have kernel drivers that access peripheral hardware directly. Where should I look for advice and documentation for programming and understanding the interface to peripheral hardware the operating system will communicate with? I will need to understand how the operating system will receive input and interact with keyboards, mice, computer monitors, hard drives, USB, etc. etc. This is probably the area I know least about. I have the Intel instruction set manuals and have been getting more familiar with assembly programming, so the CPU side of things is what I know the most about. At this point I'm thinking that I'd like to implement the Linux system calls within my operating system so that programs that run on Linux can run on my operating system. I want my operating system to use the ELF binary format. I wonder what obstacles I have to overcome to achieve this Linux compatibility. Are the main things implementing the system calls that Linux provides, and using the ELF format? What else? I am also interested in people's thoughts about why it might not be a good idea to make your own operating system, and why it is a good idea to make your own operating system. Thank you for any input.

  Read the article

• Hidden features of Perl?

  - by Adam Bellaire

  What are some really useful but esoteric language features in Perl that you've actually been able to employ to do useful work? Guidelines: Try to limit answers to the Perl core and not CPAN Please give an example and a short description Hidden Features also found in other languages' Hidden Features: (These are all from Corion's answer) C# Duff's Device Portability and Standardness Quotes for whitespace delimited lists and strings Aliasable namespaces Java Static Initalizers JavaScript Functions are First Class citizens Block scope and closure Calling methods and accessors indirectly through a variable Ruby Defining methods through code PHP Pervasive online documentation Magic methods Symbolic references Python One line value swapping Ability to replace even core functions with your own functionality Other Hidden Features: Operators: The bool quasi-operator The flip-flop operator Also used for list construction The ++ and unary - operators work on strings The repetition operator The spaceship operator The || operator (and // operator) to select from a set of choices The diamond operator Special cases of the m// operator The tilde-tilde "operator" Quoting constructs: The qw operator Letters can be used as quote delimiters in q{}-like constructs Quoting mechanisms Syntax and Names: There can be a space after a sigil You can give subs numeric names with symbolic references Legal trailing commas Grouped Integer Literals hash slices Populating keys of a hash from an array Modules, Pragmas, and command-line options: use strict and use warnings Taint checking Esoteric use of -n and -p CPAN overload::constant IO::Handle module Safe compartments Attributes Variables: Autovivification The $[ variable tie Dynamic Scoping Variable swapping with a single statement Loops and flow control: Magic goto for on a single variable continue clause Desperation mode Regular expressions: The \G anchor (?{}) and '(??{})` in regexes Other features: The debugger Special code blocks such as BEGIN, CHECK, and END The DATA block New Block Operations Source Filters Signal Hooks map (twice) Wrapping built-in functions The eof function The dbmopen function Turning warnings into errors Other tricks, and meta-answers: cat files, decompressing gzips if needed Perl Tips See Also: Hidden features of C Hidden features of C# Hidden features of C++ Hidden features of Java Hidden features of JavaScript Hidden features of Ruby Hidden features of PHP Hidden features of Python

  Read the article

• Getting error detail from WCF REST

  - by Keith

  I have a REST service consumed by a .Net WCF client. When an error is encountered the REST service returns an HTTP 400 Bad Request with the response body containing JSON serialised details. If I execute the request using Fiddler, Javascript or directly from C# I can easily access the response body when an error occurs. However, I'm using a WCF ChannelFactory with 6 quite complex interfaces. The exception thrown by this proxy is always a ProtocolException, with no useful details. Is there any way to get the response body when I get this error? Update I realise that there are a load of different ways to do this using .Net and that there are other ways to get the error response. They're useful to know but don't answer this question. The REST services we're using will change and when they do the complex interfaces get updated. Using the ChannelFactory with the new interfaces means that we'll get compile time (rather than run time) exceptions and make these a lot easier to maintain and update the code. Is there any way to get the response body for an error HTTP status when using WCF Channels?

  Read the article

• How to estimate the contribution of an individual to a software project?

  - by Amit Kumar

  I work on a software project and would like to estimate the percentage out of the total contribution that I have put in the development of the software. Is there some tool doing this? Such a tool can be useful for appraisals or negotiations, for example. After all, we work for money (yes, not only money, put the point remains). I think there is enough hand-waving for the most important things. The estimation is very subjective (at least to me now) but I do not know of any tool that provides even a subjective estimate. I know of Sloccount that spells out the total effort using the lines of code but not on per-developer basis. My idea of an ideal tool for this purpose would: measure the complexity of the code (more complex is more effort, but more effort is not necessarily more contribution) measure the decomposibility/flexibility of the software (more decomposable is better) how much library code is used -- using library code speeds up the development process, increases the associated risk and requires the developer to know from before or learn about the library. be intelligent enough to differentiate between "who wrote the code", "who copied the code" and "who indented the code". It is difficult to differentiate between the complexity in the implementation and the intrinsic complexity of the problem. Perhaps a comparison can be made with an equivalent open source counterpart if there is, or for each submodule separately. If there is no such tool, is there no merit in having such a tool? Or do you believe in "I do work, I do not measure"? It takes time after all. Perhaps the project manager should do this estimation continuously, say, weekly. Are there any standards? Yes, standardization is difficult because every project has a different goal, but difficult does not mean it is not useful.

  Read the article

• Algorithm to match list of regular expressions

  - by DSII

  I have two algorithmic questions for a project I am working on. I have thought about these, and have some suspicions, but I would love to hear the community's input as well. Suppose I have a string, and a list of N regular expressions (actually they are wildcard patterns representing a subset of full regex functionality). I want to know whether the string matches at least one of the regular expressions in the list. Is there a data structure that can allow me to match the string against the list of regular expressions in sublinear (presumably logarithmic) time? This is an extension of the previous problem. Suppose I have the same situation: a string and a list of N regular expressions, only now each of the regular expressions is paired with an offset within the string at which the match must begin (or, if you prefer, each of the regular expressions must match a substring of the given string beginning at the given offset). To give an example, suppose I had the string: This is a test string and the regex patterns and offsets: (a) his.* at offset 0 (b) his.* at offset 1 The algorithm should return true. Although regex (a) does not match the string beginning at offset 0, regex (b) does match the substring beginning at offset 1 ("his is a test string"). Is there a data structure that can allow me to solve this problem in sublinear time? One possibly useful piece of information is that often, many of the offsets in the list of regular expressions are the same (i.e. often we are matching the substring at offset X many times). This may be useful to leverage the solution to problem #1 above. Thank you very much in advance for any suggestions you may have!

  Read the article

• When and how should independent hierarchies be used in clojure?

  - by Rob Lachlan

  Clojure's system for creating an ad hoc hierarchy of keywords is familiar to most people who have spent a bit of time with the language. For example, most demos and presentations of the language include examples such as (derive ::child ::parent) and they go on to show how this can be used for multi-method dispatch. In all of the slides and presentations that I've seen, they use the global hierarchy. But it is possible to put keyword relationships in independent hierarchies, by using (derive h ::child ::parent), where h is created by (make-hierarchy). Some questions, therefore: Are there any guidelines on when this is useful or necessary? Are there any functions for manipulating hierarchies? Merging is particularly useful, so I do this: (defn merge-h [& hierarchies] (apply merge-with (cons #(merge-with clojure.set/union %1 %2) hierarchies)) But I was wondering if such functions already exist somewhere. EDIT: Changed "custom" hierarchy to "independent" hierarchy, since that term better describes this animal. Also, I've done some research and included my own answer below. Further comments are welcome.

  Read the article

• NetBeans Tips and Tricks

  - by cdmckay

  I just saw an Eclipse tips & tricks post and was wondering if anyone had any tips & tricks for my IDE of choice: NetBeans. Here's a few I know and find to be useful: Removing a package: After you remove a package in NetBeans, it sticks around as a grayed-out package in your Project view. To get rid of that, switch to Files view and delete the directory. Alt-Insert (in Windows) opens up a Generate submenu at your cursor. A nice shortcut for quickly generating getters/setters (among other things). Selecting a chunk of code, right-clicking and then clicking "Refactor Introduce Method" will have NetBeans introduce a method, complete with arguments and return value. Of course you have to make sure the chunk of code only has one return value. Sometimes when you run a build and it crashes, the Java window sticks around at the bottom. I used to just click X until Windows let me End Task, but there's a nicer way to get rid of them. Click "Run Stop Build/Run" and NetBeans will close the window for you. It'll even let you close multiple applications at once. These may seem obvious to grizzled NetBeans developers, but I thought they might be useful for NetBeans newbs like me. Anyone else have any tips/tricks to share? Here are some from the comments: NetBeans allows for code templates. You can even add yours on the Code Templates tab under the Editor settings on the Options window. Some examples: Type sout and hit the tab key as a shorcut for System.out.println("") Type psvm and hit the tab key as a shorcut for public static void main(String args[]) {} Ctrl Shift C: Comments out the selected block of code. Alt Shift F: Formats the selected block of code. Ctrl E: Deletes current line. Ctrl Shift I: Fixes your imports, handy if you've just written a piece of code that needs a lot of packages imported.

  Read the article

• Vista 64-bits development tools

  - by Workshop Alex

  Well, okay. There's Visual Studio 2008 and Embarcadero Delphi/Studio that are both able to create 64-bits .NET applications for Vista. And of course a lot of 32-bits applications will run on 64-bits Vista. If not, it's always possible to install VMWare to create a virtual 32-bits Windows XP system to run 32-bits applications. So, plenty of options. But what I would like to see is a list of true 64-bits applications for Windows Vista and better. So if you know any useful 64-bits product, please share! (Especially compilers that generate native 64-bits code.) Tools would basically be anything that would make development a bit easier. Thus, debugging tools, image processing tools to create icons and bitmaps, hex editors to check the contents of binary files, XML editors to change XML files, etc. The tools from SysInternals, for example, seem to provide 64-bits versions or even support 64-bits systems natively. But how about all those other editors, viewers, browsers and other tools that we developers like to use? A 64-bits version of the Norton Commander/Midnight Commander or other file managers would be nice too. And with compilers, how about COBOL/ForTran/ADA/SmallTalk/Lisp/Whatever compiler/languages for Vista? I would just like to see a complete list of anything useful for 64-bits development.

  Read the article

• Keeping track of leading zeros with BitSet in Java

  - by Ryan

  So, according to this question there are two ways to look at the size of a BitSet. size(), which is legacy and not really useful. I agree with this. The size is 64 after doing: BitSet b = new BitSet(8); length(), which returns the index of the highest set bit. In the above example, length() will return 0. This is somewhat useful, but doesn't accurately reflect the number of bits the BitSet is supposed to be representing in the event you have leading zeros. The information I'm dealing with rarely(if ever) falls evenly into 8-bit bytes, and the leading 0s are just as important to me as the 1s. I have some data fields that are 333 bits long, some that are 20, etc. Is there a better way to deal with bit-level details in Java that will keep track of leading zeros? Otherwise, I'm going to have to 'roll my own', so to speak. To which I have a few ideas already, but I'd prefer not to reinvent the wheel if possible.

  Read the article

• Why is an Add method required for { } initialization?

  - by Dan Tao

  To use initialization syntax like this: var contacts = new ContactList { { "Dan", "[email protected]" }, { "Eric", "[email protected]" } }; ...my understanding is that my ContactList type would need to define an Add method that takes two string parameters: public void Add(string name, string email); What's a bit confusing to me about this is that the { } initializer syntax seems most useful when creating read-only or fixed-size collections. After all it is meant to mimic the initialization syntax for an array, right? (OK, so arrays are not read-only; but they are fixed size.) And naturally it can only be used when the collection's contents are known (at least the number of elements) at compile-time. So it would almost seem that the main requirement for using this collection initializer syntax (having an Add method and therefore a mutable collection) is at odds with the typical case in which it would be most useful. I'm sure I haven't put as much thought into this matter as the C# design team; it just seems that there could have been different rules for this syntax that would have meshed better with its typical usage scenarios. Am I way off base here? Is the desire to use the { } syntax to initialize fixed-size collections not as common as I think? What other factors might have influenced the formulation of the requirements for this syntax that I'm simply not thinking of?

  Read the article

• How to log correct context with Threadpool threads using log4net?

  - by myotherme

  I am trying to find a way to log useful context from a bunch of threads. The problem is that a lot of code is dealt with on Events that are arriving via threadpool threads (as far as I can tell) so their names are not in relation to any context. The problem can be demonstrated with the following code: class Program { private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType); static void Main(string[] args) { new Thread(TestThis).Start("ThreadA"); new Thread(TestThis).Start("ThreadB"); Console.ReadLine(); } private static void TestThis(object name) { var nameStr = (string)name; Thread.CurrentThread.Name = nameStr; log4net.ThreadContext.Properties["ThreadContext"] = nameStr; log4net.LogicalThreadContext.Properties["LogicalThreadContext"] = nameStr; log.Debug("From Thread itself"); ThreadPool.QueueUserWorkItem(x => log.Debug("From threadpool Thread: " + nameStr)); } } The Conversion pattern is: %date [%thread] %-5level %logger [%property] - %message%newline The output is like so: 2010-05-21 15:08:02,357 [ThreadA] DEBUG LogicalContextTest.Program [{LogicalThreadContext=ThreadA, log4net:HostName=xxx, ThreadContext=ThreadA}] - From Thread itself 2010-05-21 15:08:02,357 [ThreadB] DEBUG LogicalContextTest.Program [{LogicalThreadContext=ThreadB, log4net:HostName=xxx, ThreadContext=ThreadB}] - From Thread itself 2010-05-21 15:08:02,404 [7] DEBUG LogicalContextTest.Program [{log4net:HostName=xxx}] - From threadpool Thread: ThreadA 2010-05-21 15:08:02,420 [16] DEBUG LogicalContextTest.Program [{log4net:HostName=xxx}] - From threadpool Thread: ThreadB As you can see the last two rows have no Names of useful information to distinguish the 2 threads, other than manually adding the name to the message (which I want to avoid). How can I get the Name/Context into the log for the threadpool threads without adding it to the message at every call?

  Read the article

• notify listener inside or outside inner synchronization

  - by Jary Zeels

  Hello all, I am struggling with a decision. I am writing a thread-safe library/API. Listeners can be registered, so the client is notified when something interesting happens. Which of the two implementations is most common? class MyModule { protected Listener listener; protected void somethingHappens() { synchronized(this) { ... do useful stuff ... listener.notify(); } } } or class MyModule { protected Listener listener; protected void somethingHappens() { Listener l = null; synchronized(this) { ... do useful stuff ... l = listener; } l.notify(); } } In the first implementation, the listener is notified inside the synchronization. In the second implementation, this is done outside the synchronization. I feel that the second one is advised, as it makes less room for potential deadlocks. But I am having trouble to convince myself. A downside of the second imlementation is that the client might receive 'incorrect' notifications, which happens if it accessed the module prior to the l.notify() statement. thanks a lot

  Read the article

• ADO/SQL Server: What is the error code for "timeout expired"?

  - by Ian Boyd

  i'm trying to trap a "timeout expired" error from ADO. When a timeout happens, ADO returns: Number: 0x80040E31 (DB_E_ABORTLIMITREACHED in oledberr.h) SQLState: HYT00 NativeError: 0 The NativeError of zero makes sense, since the timeout is not a function of the database engine (i.e. SQL Server), but of ADO's internal timeout mechanism. The Number (i.e. the COM hresult) looks useful, but the definition of DB_E_ABORTLIMITREACHED in oledberr.h says: Execution stopped because a resource limit was reached. No results were returned. This error could apply to things besides "timeout expired" (some potentially server-side), such as a governor that limits: CPU usage I/O reads/writes network bandwidth and stops a query. The final useful piece is SQLState, which is a database-independent error code system. Unfortunately the only reference for SQLState error codes i can find have no mention of HYT00. What to do? What do do? Note: i can't trust 0x80040E31 (DB_E_ABORTLIMITREACHED) to mean "timeout expired", anymore than i could trust 0x80004005 (E_UNSPECIFIED_ERROR) to mean "Transaction was deadlocked on lock resources with another process and has been chosen as the deadlock victim". My pseudo-question becomes: does anyone have documentation on what the SQLState "HYT000" means? And my real question still remains: How can i specifically trap an ADO timeout expired exception thrown by ADO? Gotta love the questions where the developer is trying to "do the right thing", but nobody knows how to do the right thing. Also gotta love how googling for DB_E_ABORTLIMITREACHED and this question is #9, with MSDN nowhere to be found. Update 3 From the OLEdb ICommand.Execute reference: DB_E_ABORTLIMITREACHED Execution has been aborted because a resource limit has been reached. For example, a query timed out. No results have been returned. "For example", meaning not an exhaustive list.

  Read the article

• CouchDB, HDFS, HBase or which is right for my situation?

  - by Lucas

  Hello all, This question is regarding data storage systems such as CouchDB, HDFS and HBase, specifically, which is right. I am looking at making a simple and customized Document Management System for my organization. Basically, we need the ability to store some Word Documents, PDFs and other similar files. I also want to store metadata about these files (e.g., Author, Dates, etc). Usage permissions would also be handy, but that can probably be built using meta-data. I would also need the ability to full-text index. The ability to version, while not required would be extremely useful. I would like the ability to simply add hardware to expand the resources of the system and the system must support Network Attached Storage over the CIFS or NFS protocol(s). I have read about CouchDB, HDFS and HBase. My preferred programming language is C# as all of my end-users will be running Windows machines and I will want to make both web and winforms client implementations. My question is which solution best fits my needs? Based on my research it appears that CouchDB (utilizing the CouchDB-Lounge and CouchDB-Lucene) perfectly fits my needs. However, I am worried that since I have worked with CouchDB that I might be overlooking something useful for my needs in HDFS or HBase or something similar due to a bias. Any and all opinions are welcome as I am looking for the community input as I really do not want to make the wrong choice at the start of my project. Please ask if you need more information. I thank you all for your time, input and assistance.

  Read the article

• Using Pylint with Django

  - by rcreswick

  I would very much like to integrate pylint into the build process for my python projects, but I have run into one show-stopper: One of the error types that I find extremely useful--:E1101: *%s %r has no %r member*--constantly reports errors when using common django fields, for example: E1101:125:get_user_tags: Class 'Tag' has no 'objects' member which is caused by this code: def get_user_tags(username): """ Gets all the tags that username has used. Returns a query set. """ return Tag.objects.filter( ## This line triggers the error. tagownership__users__username__exact=username).distinct() # Here is the Tag class, models.Model is provided by Django: class Tag(models.Model): """ Model for user-defined strings that help categorize Events on on a per-user basis. """ name = models.CharField(max_length=500, null=False, unique=True) def __unicode__(self): return self.name How can I tune Pylint to properly take fields such as objects into account? (I've also looked into the Django source, and I have been unable to find the implementation of objects, so I suspect it is not "just" a class field. On the other hand, I'm fairly new to python, so I may very well have overlooked something.) Edit: The only way I've found to tell pylint to not warn about these warnings is by blocking all errors of the type (E1101) which is not an acceptable solution, since that is (in my opinion) an extremely useful error. If there is another way, without augmenting the pylint source, please point me to specifics :) See here for a summary of the problems I've had with pychecker and pyflakes -- they've proven to be far to unstable for general use. (In pychecker's case, the crashes originated in the pychecker code -- not source it was loading/invoking.)

  Read the article

• How/when to hire new programmers, and how to integrate them?

  - by Shaul

  Hiring new programmers, especially in a small company, can often present a Catch-22 situation. We have too much work to do, so we need to hire new programmers. But we can't hire new programmers now, because they will need mentoring and several months of learning curve in your industry/product/environment before they're useful, and none of the programmers has time to be a mentor to a new programmer, because they're all completely swamped with the current work load. That may be a slightly frivolous way of describing the situation, but nevertheless, it's difficult for a small company on a tight budget to justify hiring someone who is not only going to be unproductive for a long time, but will also take away from the performance of the current programmers. How have you dealt with this kind of situation? When is the best time to hire someone? What are the best tasks to assign to a new team member so that they can learn their way around your code base and start getting their hands dirty as quickly as possible? How do you get the new guy useful without bogging your existing programmers down in too much mentoring? Any comments & suggestions you have are much appreciated!

  Read the article

• How to identify ideas and concepts in a given text

  - by Nick

  I'm working on a project at the moment where it would be really useful to be able to detect when a certain topic/idea is mentioned in a body of text. For instance, if the text contained: Maybe if you tell me a little more about who Mr Balzac is, that would help. It would also be useful if I could have a description of his appearance, or even better a photograph? It'd be great to be able to detect that the person has asked for a photograph of Mr Balzac. I could take a really naïve approach and just look for the word "photo" or "photograph", but this would obviously be no good if they wrote something like: Please, never send me a photo of Mr Balzac. Does anyone know where to start with this? Is it even possible? I've looked into things like nltk, but I've yet to find an example of someone doing something similar and am still not entirely sure what this kind of analysis is called. Any help that can get me off the ground would be great. Thanks!

  Read the article

• Where to Store ID Field In Silverlight

  - by Blake Blackwell

  I am trying to use the MVVM pattern, and I am wondering where I place an ID value. Do I create a TextBlock that has its visibility property set to collapsed? Or is there a better place to store this kind of data? Currently the command parameter is set to: CommandParameter="{Binding ElementName=Name,Path=Text}" But I'd rather it be something like: CommandParameter="{Binding ElementName=Id,Path=Text}" I'm totally up for suggestions on what the best way there is to do this, since I'm new to this pattern and presentation language. <ListBox x:Name="MyListBox" ItemsSource="{Binding MyData, Mode=TwoWay}" BorderThickness="0"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <CheckBox x:Name="Visible" IsChecked="{Binding Visible, Mode=TwoWay}" Command="{Binding ElementName=MyListBox, Path=DataContext.MyCommand}" CommandParameter="{Binding ElementName=Name,Path=Text}" /> <TextBlock Text="{Binding Name}" /> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> EDIT: Option 1 <CheckBox x:Name="Visible" IsChecked="{Binding Visible, Mode=TwoWay}" Command="{Binding ElementName=MyListBox, Path=DataContext.MyCommand}" CommandParameter="{Binding Id}" /> This option gives me just the Id, which is useful in many situations. EDIT: Option 2 <CheckBox x:Name="Visible" IsChecked="{Binding Visible, Mode=TwoWay}" Command="{Binding ElementName=MyListBox, Path=DataContext.MyCommand}" CommandParameter="{Binding}" /> This option gives me the full model, which is even useful for my particular situation.

  Read the article

• Is it bad practice to make a setter return "this"?

  - by Ken Liu

  Is it a good or bad idea to make setters in java return "this"? public Employee setName(String name){ this.name = name; return this; } This pattern can be useful because then you can chain setters like this: list.add(new Employee().setName("Jack Sparrow").setId(1).setFoo("bacon!")); instead of this: Employee e = new Employee(); e.setName("Jack Sparrow"); ...and so on... list.add(e); ...but it sort of goes against standard convention. I suppose it might be worthwhile just because it can make that setter do something else useful. I've seen this pattern used some places (e.g. JMock, JPA), but it seems uncommon, and only generally used for very well defined APIs where this pattern is used everywhere. Update: What I've described is obviously valid, but what I am really looking for is some thoughts on whether this is generally acceptable, and if there are any pitfalls or related best practices. I know about the Builder pattern but it is a little more involved then what I am describing - as Josh Bloch describes it there is an associated static Builder class for object creation.

  Read the article

< Previous Page | 47 48 49 50 51 52 53 54 55 56 57 58  | Next Page >