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  • ANTS CLR and Memory Profiler In Depth Review (Part 1 of 2 &ndash; CLR Profiler)

    - by ToStringTheory
    One of the things that people might not know about me, is my obsession to make my code as efficient as possible.  Many people might not realize how much of a task or undertaking that this might be, but it is surely a task as monumental as climbing Mount Everest, except this time it is a challenge for the mind…  In trying to make code efficient, there are many different factors that play a part – size of project or solution, tiers, language used, experience and training of the programmer, technologies used, maintainability of the code – the list can go on for quite some time. I spend quite a bit of time when developing trying to determine what is the best way to implement a feature to accomplish the efficiency that I look to achieve.  One program that I have recently come to learn about – Red Gate ANTS Performance (CLR) and Memory profiler gives me tools to accomplish that job more efficiently as well.  In this review, I am going to cover some of the features of the ANTS profiler set by compiling some hideous example code to test against. Notice As a member of the Geeks With Blogs Influencers program, one of the perks is the ability to review products, in exchange for a free license to the program.  I have not let this affect my opinions of the product in any way, and Red Gate nor Geeks With Blogs has tried to influence my opinion regarding this product in any way. Introduction The ANTS Profiler pack provided by Red Gate was something that I had not heard of before receiving an email regarding an offer to review it for a license.  Since I look to make my code efficient, it was a no brainer for me to try it out!  One thing that I have to say took me by surprise is that upon downloading the program and installing it you fill out a form for your usual contact information.  Sure enough within 2 hours, I received an email from a sales representative at Red Gate asking if she could help me to achieve the most out of my trial time so it wouldn’t go to waste.  After replying to her and explaining that I was looking to review its feature set, she put me in contact with someone that setup a demo session to give me a quick rundown of its features via an online meeting.  After having dealt with a massive ordeal with one of my utility companies and their complete lack of customer service, Red Gates friendly and helpful representatives were a breath of fresh air, and something I was thankful for. ANTS CLR Profiler The ANTS CLR profiler is the thing I want to focus on the most in this post, so I am going to dive right in now. Install was simple and took no time at all.  It installed both the profiler for the CLR and Memory, but also visual studio extensions to facilitate the usage of the profilers (click any images for full size images): The Visual Studio menu options (under ANTS menu) Starting the CLR Performance Profiler from the start menu yields this window If you follow the instructions after launching the program from the start menu (Click File > New Profiling Session to start a new project), you are given a dialog with plenty of options for profiling: The New Session dialog.  Lots of options.  One thing I noticed is that the buttons in the lower right were half-covered by the panel of the application.  If I had to guess, I would imagine that this is caused by my DPI settings being set to 125%.  This is a problem I have seen in other applications as well that don’t scale well to different dpi scales. The profiler options give you the ability to profile: .NET Executable ASP.NET web application (hosted in IIS) ASP.NET web application (hosted in IIS express) ASP.NET web application (hosted in Cassini Web Development Server) SharePoint web application (hosted in IIS) Silverlight 4+ application Windows Service COM+ server XBAP (local XAML browser application) Attach to an already running .NET 4 process Choosing each option provides a varying set of other variables/options that one can set including options such as application arguments, operating path, record I/O performance performance counters to record (43 counters in all!), etc…  All in all, they give you the ability to profile many different .Net project types, and make it simple to do so.  In most cases of my using this application, I would be using the built in Visual Studio extensions, as they automatically start a new profiling project in ANTS with the options setup, and start your program, however RedGate has made it easy enough to profile outside of Visual Studio as well. On the flip side of this, as someone who lives most of their work life in Visual Studio, one thing I do wish is that instead of opening an entirely separate application/gui to perform profiling after launching, that instead they would provide a Visual Studio panel with the information, and integrate more of the profiling project information into Visual Studio.  So, now that we have an idea of what options that the profiler gives us, its time to test its abilities and features. Horrendous Example Code – Prime Number Generator One of my interests besides development, is Physics and Math – what I went to college for.  I have especially always been interested in prime numbers, as they are something of a mystery…  So, I decided that I would go ahead and to test the abilities of the profiler, I would write a small program, website, and library to generate prime numbers in the quantity that you ask for.  I am going to start off with some terrible code, and show how I would see the profiler being used as a development tool. First off, the IPrimes interface (all code is downloadable at the end of the post): interface IPrimes { IEnumerable<int> GetPrimes(int retrieve); } Simple enough, right?  Anything that implements the interface will (hopefully) provide an IEnumerable of int, with the quantity specified in the parameter argument.  Next, I am going to implement this interface in the most basic way: public class DumbPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _analyzing = 4; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; //start dividing at 2 //divide until number is reached, or determined not prime for (int i = 2; i < _analyzing && isPrime; i++) { //if (i) goes into _analyzing without a remainder, //_analyzing is NOT prime if (_analyzing % i == 0) isPrime = false; } //if it is prime, add to found list if (isPrime) _foundPrimes.Add(_analyzing); //increment number to analyze next _analyzing++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } This is the simplest way to get primes in my opinion.  Checking each number by the straight definition of a prime – is it divisible by anything besides 1 and itself. I have included this code in a base class library for my solution, as I am going to use it to demonstrate a couple of features of ANTS.  This class library is consumed by a simple non-MVVM WPF application, and a simple MVC4 website.  I will not post the WPF code here inline, as it is simply an ObservableCollection<int>, a label, two textbox’s, and a button. Starting a new Profiling Session So, in Visual Studio, I have just completed my first stint developing the GUI and DumbPrimes IPrimes class, so now I want to check my codes efficiency by profiling it.  All I have to do is build the solution (surprised initiating a profiling session doesn’t do this, but I suppose I can understand it), and then click the ANTS menu, followed by Profile Performance.  I am then greeted by the profiler starting up and already monitoring my program live: You are provided with a realtime graph at the top, and a pane at the bottom giving you information on how to proceed.  I am going to start by asking my program to show me the first 15000 primes: After the program finally began responding again (I did all the work on the main UI thread – how bad!), I stopped the profiler, which did kill the process of my program too.  One important thing to note, is that the profiler by default wants to give you a lot of detail about the operation – line hit counts, time per line, percent time per line, etc…  The important thing to remember is that this itself takes a lot of time.  When running my program without the profiler attached, it can generate the 15000 primes in 5.18 seconds, compared to 74.5 seconds – almost a 1500 percent increase.  While this may seem like a lot, remember that there is a trade off.  It may be WAY more inefficient, however, I am able to drill down and make improvements to specific problem areas, and then decrease execution time all around. Analyzing the Profiling Session After clicking ‘Stop Profiling’, the process running my application stopped, and the entire execution time was automatically selected by ANTS, and the results shown below: Now there are a number of interesting things going on here, I am going to cover each in a section of its own: Real Time Performance Counter Bar (top of screen) At the top of the screen, is the real time performance bar.  As your application is running, this will constantly update with the currently selected performance counters status.  A couple of cool things to note are the fact that you can drag a selection around specific time periods to drill down the detail views in the lower 2 panels to information pertaining to only that period. After selecting a time period, you can bookmark a section and name it, so that it is easy to find later, or after reloaded at a later time.  You can also zoom in, out, or fit the graph to the space provided – useful for drilling down. It may be hard to see, but at the top of the processor time graph below the time ticks, but above the red usage graph, there is a green bar. This bar shows at what times a method that is selected in the ‘Call tree’ panel is called. Very cool to be able to click on a method and see at what times it made an impact. As I said before, ANTS provides 43 different performance counters you can hook into.  Click the arrow next to the Performance tab at the top will allow you to change between different counters if you have them selected: Method Call Tree, ADO.Net Database Calls, File IO – Detail Panel Red Gate really hit the mark here I think. When you select a section of the run with the graph, the call tree populates to fill a hierarchical tree of method calls, with information regarding each of the methods.   By default, methods are hidden where the source is not provided (framework type code), however, Red Gate has integrated Reflector into ANTS, so even if you don’t have source for something, you can select a method and get the source if you want.  Methods are also hidden where the impact is seen as insignificant – methods that are only executed for 1% of the time of the overall calling methods time; in other words, working on making them better is not where your efforts should be focused. – Smart! Source Panel – Detail Panel The source panel is where you can see line level information on your code, showing the code for the currently selected method from the Method Call Tree.  If the code is not available, Reflector takes care of it and shows the code anyways! As you can notice, there does seem to be a problem with how ANTS determines what line is the actual line that a call is completed on.  I have suspicions that this may be due to some of the inline code optimizations that the CLR applies upon compilation of the assembly.  In a method with comments, the problem is much more severe: As you can see here, apparently the most offending code in my base library was a comment – *gasp*!  Removing the comments does help quite a bit, however I hope that Red Gate works on their counter algorithm soon to improve the logic on positioning for statistics: I did a small test just to demonstrate the lines are correct without comments. For me, it isn’t a deal breaker, as I can usually determine the correct placements by looking at the application code in the region and determining what makes sense, but it is something that would probably build up some irritation with time. Feature – Suggest Method for Optimization A neat feature to really help those in need of a pointer, is the menu option under tools to automatically suggest methods to optimize/improve: Nice feature – clicking it filters the call tree and stars methods that it thinks are good candidates for optimization.  I do wish that they would have made it more visible for those of use who aren’t great on sight: Process Integration I do think that this could have a place in my process.  After experimenting with the profiler, I do think it would be a great benefit to do some development, testing, and then after all the bugs are worked out, use the profiler to check on things to make sure nothing seems like it is hogging more than its fair share.  For example, with this program, I would have developed it, ran it, tested it – it works, but slowly. After looking at the profiler, and seeing the massive amount of time spent in 1 method, I might go ahead and try to re-implement IPrimes (I actually would probably rewrite the offending code, but so that I can distribute both sets of code easily, I’m just going to make another implementation of IPrimes).  Using two pieces of knowledge about prime numbers can make this method MUCH more efficient – prime numbers fall into two buckets 6k+/-1 , and a number is prime if it is not divisible by any other primes before it: public class SmartPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _k = 1; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; int potentialPrime; //analyze 6k-1 //assign the value to potential potentialPrime = 6 * _k - 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); if (_foundPrimes.Count() == retrieve) break; //analyze 6k+1 //assign the value to potential potentialPrime = 6 * _k + 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); //increment k to analyze next _k++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } Now there are definitely more things I can do to help make this more efficient, but for the scope of this example, I think this is fine (but still hideous)! Profiling this now yields a happy surprise 27 seconds to generate the 15000 primes with the profiler attached, and only 1.43 seconds without.  One important thing I wanted to call out though was the performance graph now: Notice anything odd?  The %Processor time is above 100%.  This is because there is now more than 1 core in the operation.  A better label for the chart in my mind would have been %Core time, but to each their own. Another odd thing I noticed was that the profiler seemed to be spot on this time in my DumbPrimes class with line details in source, even with comments..  Odd. Profiling Web Applications The last thing that I wanted to cover, that means a lot to me as a web developer, is the great amount of work that Red Gate put into the profiler when profiling web applications.  In my solution, I have a simple MVC4 application setup with 1 page, a single input form, that will output prime values as my WPF app did.  Launching the profiler from Visual Studio as before, nothing is really different in the profiler window, however I did receive a UAC prompt for a Red Gate helper app to integrate with the web server without notification. After requesting 500, 1000, 2000, and 5000 primes, and looking at the profiler session, things are slightly different from before: As you can see, there are 4 spikes of activity in the processor time graph, but there is also something new in the call tree: That’s right – ANTS will actually group method calls by get/post operations, so it is easier to find out what action/page is giving the largest problems…  Pretty cool in my mind! Overview Overall, I think that Red Gate ANTS CLR Profiler has a lot to offer, however I think it also has a long ways to go.  3 Biggest Pros: Ability to easily drill down from time graph, to method calls, to source code Wide variety of counters to choose from when profiling your application Excellent integration/grouping of methods being called from web applications by request – BRILLIANT! 3 Biggest Cons: Issue regarding line details in source view Nit pick – Processor time vs. Core time Nit pick – Lack of full integration with Visual Studio Ratings Ease of Use (7/10) – I marked down here because of the problems with the line level details and the extra work that that entails, and the lack of better integration with Visual Studio. Effectiveness (10/10) – I believe that the profiler does EXACTLY what it purports to do.  Especially with its large variety of performance counters, a definite plus! Features (9/10) – Besides the real time performance monitoring, and the drill downs that I’ve shown here, ANTS also has great integration with ADO.Net, with the ability to show database queries run by your application in the profiler.  This, with the line level details, the web request grouping, reflector integration, and various options to customize your profiling session I think create a great set of features! Customer Service (10/10) – My entire experience with Red Gate personnel has been nothing but good.  their people are friendly, helpful, and happy! UI / UX (8/10) – The interface is very easy to get around, and all of the options are easy to find.  With a little bit of poking around, you’ll be optimizing Hello World in no time flat! Overall (8/10) – Overall, I am happy with the Performance Profiler and its features, as well as with the service I received when working with the Red Gate personnel.  I WOULD recommend you trying the application and seeing if it would fit into your process, BUT, remember there are still some kinks in it to hopefully be worked out. My next post will definitely be shorter (hopefully), but thank you for reading up to here, or skipping ahead!  Please, if you do try the product, drop me a message and let me know what you think!  I would love to hear any opinions you may have on the product. Code Feel free to download the code I used above – download via DropBox

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  • Data structures in functional programming

    - by pwny
    I'm currently playing with LISP (particularly Scheme and Clojure) and I'm wondering how typical data structures are dealt with in functional programming languages. For example, let's say I would like to solve a problem using a graph pathfinding algorithm. How would one typically go about representing that graph in a functional programming language (primarily interested in pure functional style that can be applied to LISP)? Would I just forget about graphs altogether and solve the problem some other way?

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  • Winter4Net

    - by csharp-source.net
    Winter.NET is a lightweight Spring-like inversion of control (IoC) container for .NET platform. Its main features: - XML-based objects graph configuration - compact: implements conceptually full and minimum-required features of Spring-compatible XML configuration (assembly size is less than 50kb). - fast: optimized for huge component graph configurations and small memory consumption - .NET integration: supports System.ComponentModel interfaces

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  • Storing data on server [closed]

    - by Maciekp
    1.How am I supposed to store data on server, using not only: databases,text files and images? And how someone could implement storing data in fb's graph api http://developers.facebook.com/docs/reference/api/ , so when I go to: https://graph.facebook.com/19292868552 it shows me such data(how it can be stored? I guess it's not Mysql database) PS. Link to article: http://jayant7k.blogspot.com/2009/05/how-facebook-stores-billions-of-photos.html <- How can concurrent users writing requests be solved(while storing data in text file).

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  • Diagonal line of sight with two corners

    - by Ash Blue
    Right now I'm using Bresenham's line algorithm for line of sight. The problem is I've found an edge case where players can look through walls. Occurs when the player looks between two corners of a wall with a gap on the other side at specific angles. The result I want is for the tile between two walls to be marked invalid as so. What is the fastest way to modify Bresenham's line algorithm to solve this? If there isn't a good solution, is there a better suited algorithm? Any ideas are welcome. Please note the solution should also be capable of supporting 3d. Edit: For the working source code and an interactive demo of the completed product please see http://ashblue.github.io/javascript-pathfinding/

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  • "Best fit" to avoid reuse of object instances in a collection

    - by Simon
    Imagine I have a collection of object instances which represent activities for a user to undertake. Dependent on user attributes, I have to randomly select instances to present activities to the user. For some users, I need to present more activities to them than there are available activities in which case, I want to use the following algorithm. If all available activities have already been presented to the user, then re-select a "used" activity, selecting the earliest presented activity ordered by frequency of use. In other words, try to reduce repetition and where repetition is unavoidable, use the instances which have been repeated less often and were presented furthest back in time. Before I go on to code that algorithm, I wondered if there is some existing pattern I can re-use? [EDIT] "Furthest back in time" is not relevant as I will pass the algorithm an ordered collection of used instances where the first entry is the first presented.

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  • 3D RTS pathfinding

    - by xcrypt
    I understand the A* algorithm, but I have some trouble doing it in 3D to suit the needs of my RTS Basically, in the game I'm making, there will be agents with different sizes of OBB collision boxes. I can use steering behaviours for avoiding other agents, so I don't need complete dynamic pathfinding. However, there is a problem because different agents have different collision geometry, and structures can be placed in almost any place. This means that there might be a gap between two structures where some agents can go through and some can't. A solution I have found to this problem is to do a sweep of the collision geometry of the agent from start node of the edge the pf algorithm is currently testing, to the end node of that edge. But this is probably a bit overkill since every edge the algorithm tests would also have to create and test with a collision geometry sweep. What are some reasonable approaches to this problem? I should mention that I'd prefer not to use navmeshes, I prefer waypoints because my entire system is based on it atm.

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  • How can I obtain in-game data from Warcraft 3 from an external process?

    - by Slav
    I am implementing a behavior algorithm and would like to test it with my lovely Warcraft III game to watch how it will fight against real players. The problem I'm having is that I don't know how to obtain information about in-game state (units, structures, environment, etc.) from the running WC3 game. My algorithm needs access to the hard drive and possibly distributed computing, that's why JASS (WC3's editor language) isn't appropriate; I need to run my algorithm from a separate process. Direct3D hooking is an approach, but it wasn't done for WC3 yet and a significant drawback of that approach would be the inability to watch how the AI performs online, since it uses the viewport to issue commands. How I read in-game data from WC3 in a different process in a fastest and easiest way?

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  • Resource Monitor (resmon) in Windows Server 2008 R2

    - by Clever Human
    In Windows Server 2008 R2's Resource Monitor, is there a way to set the scale of the various graphs to be constant values instead of variable based on data? It seems to me that the utility of a graph is to get a quick overview glance at the values those graphs are showing. So if I look at the CPU graph and the line is up near the top, I can know immediately that something is using all my CPU and go investigate what. I don't really care if the CPU is jumping between .01% and 2%. Or if the network usage monitor is up near the top, I will know that all my bandwidth is being used up, and go figure out what. But the way things are now, the graphs are meaningless because the scales constantly shift. If you look at the network usage graph in one second it might have a scale out of 100kbps, and the next second have a scale based on 1mbps! So... is there a registry key or something that will peg the scale of these graphs to logical maximums? (the graph on the right hand side of the screenshot below):

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  • Logging errors caused by exceptions deep in the application

    - by Kaleb Pederson
    What are best-practices for logging deep within an application's source? Is it bad practice to have multiple event log entries for a single error? For example, let's say that I have an ETL system whose transform step involves: a transformer, pipeline, processing algorithm, and processing engine. In brief, the transformer takes in an input file, parses out records, and sends the records through the pipeline. The pipeline aggregates the results of the processing algorithm (which could do serial or parallel processing). The processing algorithm sends each record through one or more processing engines. So, I have at least four levels: Transformer - Pipeline - Algorithm - Engine. My code might then look something like the following: class Transformer { void Process(InputSource input) { try { var inRecords = _parser.Parse(input.Stream); var outRecords = _pipeline.Transform(inRecords); } catch (Exception ex) { var inner = new ProcessException(input, ex); _logger.Error("Unable to parse source " + input.Name, inner); throw inner; } } } class Pipeline { IEnumerable<Result> Transform(IEnumerable<Record> records) { // NOTE: no try/catch as I have no useful information to provide // at this point in the process var results = _algorithm.Process(records); // examine and do useful things with results return results; } } class Algorithm { IEnumerable<Result> Process(IEnumerable<Record> records) { var results = new List<Result>(); foreach (var engine in Engines) { foreach (var record in records) { try { engine.Process(record); } catch (Exception ex) { var inner = new EngineProcessingException(engine, record, ex); _logger.Error("Engine {0} unable to parse record {1}", engine, record); throw inner; } } } } } class Engine { Result Process(Record record) { for (int i=0; i<record.SubRecords.Count; ++i) { try { Validate(record.subRecords[i]); } catch (Exception ex) { var inner = new RecordValidationException(record, i, ex); _logger.Error( "Validation of subrecord {0} failed for record {1}", i, record ); } } } } There's a few important things to notice: A single error at the deepest level causes three log entries (ugly? DOS?) Thrown exceptions contain all important and useful information Logging only happens when failure to do so would cause loss of useful information at a lower level. Thoughts and concerns: I don't like having so many log entries for each error I don't want to lose important, useful data; the exceptions contain all the important but the stacktrace is typically the only thing displayed besides the message. I can log at different levels (e.g., warning, informational) The higher level classes should be completely unaware of the structure of the lower-level exceptions (which may change as the different implementations are replaced). The information available at higher levels should not be passed to the lower levels. So, to restate the main questions: What are best-practices for logging deep within an application's source? Is it bad practice to have multiple event log entries for a single error?

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  • Come up with a real-world problem in which only the best solution will do (a problem from Introduction to algorithms) [closed]

    - by Mike
    EDITED (I realized that the question certainly needs a context) The problem 1.1-5 in the book of Thomas Cormen et al Introduction to algorithms is: "Come up with a real-world problem in which only the best solution will do. Then come up with one in which a solution that is “approximately” the best is good enough." I'm interested in its first statement. And (from my understanding) it is asked to name a real-world problem where only the exact solution will work as opposed to a real-world problem where good-enough solution will be ok. So what is the difference between the exact and good enough solution. Consider some physics problem for example the simulation of the fulid flow in the permeable medium. To make this simulation happen some simplyfing assumptions have to be made when deriving a mathematical model. Otherwise the model becomes at least complex and unsolvable. Virtually any particle in the universe has its influence on the fluid flow. But not all particles are equal. Those that form the permeable medium are much more influental than the ones located light years away. Then when the mathematical model needs to be solved an exact solution can rarely be found unless the mathematical model is simple enough (wich probably means the model isn't close to reality). We take an approximate numerical method and after hours of coding and days of verification come up with the program or algorithm which is a solution. And if the model and an algorithm give results close to a real problem by some degree that is good enough soultion. Its worth noting the difference between exact solution algorithm and exact computation result. When considering real-world problems and real-world computation machines I believe all physical problems solutions where any calculations are taken can not be exact because universal physical constants are represented approximately in the computer. Any numbers are represented with the limited precision, at least limited by amount of memory available to computing machine. I can imagine plenty of problems where good-enough, good to some degree solution will work, like train scheduling, automated trading, satellite orbit calculation, health care expert systems. In that cases exact solutions can't be derived due to constraints on computation time, limitations in computer memory or due to the nature of problems. I googled this question and like what this guy suggests: there're kinds of mathematical problems that need exact solutions (little note here: because the question is taken from the book "Introduction to algorithms" the term "solution" means an algorithm or a program, which in this case gives exact answer on each input). But that's probably more of theoretical interest. So I would like to narrow down the question to: What are the real-world practical problems where only the best (exact) solution algorithm or program will do (but not the good-enough solution)? There are problems like breaking of cryptographic ciphers where only exact solution matters in practice and again in practice the process of deciphering without knowing a secret should take reasonable amount of time. Returning to the original question this is the problem where good-enough (fast-enough) solution will do there's no practical need in instant crack though it's desired. So the quality of "best" can be understood in any sense: exact, fastest, requiring least memory, having minimal possible network traffic etc. And still I want this question to be theoretical if possible. In a sense that there may be example of computer X that has limited resource R of amount Y where the best solution to problem P is the one that takes not more than available Y for inputs of size N*Y. But that's the problem of finding solution for P on computer X which is... well, good enough. My final thought that we live in a world where it is required from programming solutions to practical purposes to be good enough. In rare cases really very very good but still not the best ones. Isn't it? :) If it's not can you provide an example? Or can you name any such unsolved problem of practical interest?

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  • 11gR2 RAC ASM????

    - by Liu Maclean(???)
    11gR2 RAC?ocr?votedisk???????ASM??, ????10g??????2?RAC????????????,  ?? 11gR2 ?ASM?spfile??????ASM diskgroup???????ASM??????? ????????????,????? ASM?????mount diskgroup??????diskgroup????, ??ASM??????ASM spfile????????,?2???????? ????T.askmaclean.com?????ASM?????: hello maclean, ??spfile??ASMCMD> spget+CRSDG/rac/asmparameterfile/registry.253.787925627?????,ASM ?????ORACLE instance,?????????????diskgroup,????????????????????????????thanks.! ?????????: ?11.2??Oracle Cluterware??voting disk files?????????11.1?10.2????,11.2??voting disk file??????OCR?, ?????11.2??ocr?votedisk?????ASM? , ???11.2?voting disk file??GPNP profile??CSS voting file discovery string???? CSS voting disk file?discovery string???ASM,??????ASM discovery string???  ????????udev???????ASM???LUN, ??udev????????/dev/rasm-disk* , ????gpnptool get????gpnp profile: [grid@maclean1 trace]$ gpnptool get Warning: some command line parameters were defaulted. Resulting command line: /g01/grid/app/11.2.0/grid/bin/gpnptool.bin get -o- <?xml version="1.0" encoding="UTF-8"?><gpnp:GPnP-Profile Version="1.0" xmlns="http://www.grid-pnp.org/2005/11/gpnp-profile" xmlns:gpnp="http://www.grid-pnp.org/2005/11/gpnp-profile" xmlns:orcl="http://www.oracle.com/gpnp/2005/11/gpnp-profile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.grid-pnp.org/2005/11/gpnp-profile gpnp-profile.xsd" ProfileSequence="9" ClusterUId="452185be9cd14ff4ffdc7688ec5439bf" ClusterName="maclean-cluster" PALocation=""><gpnp:Network-Profile><gpnp:HostNetwork id="gen" HostName="*"><gpnp:Network id="net1" IP="192.168.1.0" Adapter="eth0" Use="public"/><gpnp:Network id="net2" IP="172.168.1.0" Adapter="eth1" Use="cluster_interconnect"/></gpnp:HostNetwork></gpnp:Network-Profile>< orcl:CSS-Profile id="css" DiscoveryString="+asm" LeaseDuration="400"/><orcl:ASM-Profile id="asm" DiscoveryString="/dev/rasm*" SPFile="+SYSTEMDG/maclean-cluster/asmparameterfile/registry.253.788682933"/>< ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/><ds:Reference URI=""><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"> <InclusiveNamespaces xmlns="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="gpnp orcl xsi"/></ds:Transform></ds:Transforms>< ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>L1SLg10AqGEauCQ4ne9quucITZA=</ds:DigestValue>< /ds:Reference></ds:SignedInfo><ds:SignatureValue>rTyZm9vfcQCMuian6isnAThUmsV4xPoK2fteMc1l0GIvRvHncMwLQzPM/QrXCGGTCEvgvXzUPEKzmdX2oy5vLcztN60UHr6AJtA2JYYodmrsFwEyVBQ1D6wH+HQiOe2SG9UzdQnNtWSbjD4jfZkeQWyMPfWdKm071Ek0Rfb4nxE=</ds:SignatureValue></ds:Signature></gpnp:GPnP-Profile> Success. ?????2???: <orcl:CSS-Profile id=”css” DiscoveryString=”+asm” LeaseDuration=”400?/>==»css voting disk??+ASM<orcl:ASM-Profile id=”asm” DiscoveryString=”/dev/rasm*” SPFile=”+SYSTEMDG/maclean-cluster/asmparameterfile/registry.253.788682933?/>==»??????ASM?DiscoveryString=”/dev/rasm*”,?ASM??????????????,SPFILE???ASM Parameter FILE?ALIAS ???????GPNP???ASM Parameter FILE?ALIAS,?????ASM???????SPFILE,???Diskgroup?Mount???????ASM ALIAS?????? ??????+SYSTEMDG/maclean-cluster/asmparameterfile/registry.253.788682933??SPFILE?ASM??????: [grid@maclean1 wallets]$ sqlplus / as sysasm SQL*Plus: Release 11.2.0.3.0 Production on Tue Jul 17 05:45:35 2012 Copyright (c) 1982, 2011, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production With the Real Application Clusters and Automatic Storage Management options SQL> set linesize 140 pagesize 1400 col "FILE NAME" format a40 set head on select NAME "FILE NAME", AU_KFFXP "AU NUMBER", NUMBER_KFFXP "FILE NUMBER", DISK_KFFXP "DISK NUMBER" from x$kffxp, v$asm_alias where GROUP_KFFXP = GROUP_NUMBER and NUMBER_KFFXP = FILE_NUMBER and name in ('REGISTRY.253.788682933') order by DISK_KFFXP,AU_KFFXP; FILE NAME AU NUMBER FILE NUMBER DISK NUMBER ---------------------------------------- ---------- ----------- ----------- REGISTRY.253.788682933 39 253 1 REGISTRY.253.788682933 35 253 3 REGISTRY.253.788682933 35 253 4 SQL> col path for a50 SQL> select disk_number,path from v$asm_disk where disk_number in (1,3,4) and GROUP_NUMBER=3; DISK_NUMBER PATH ----------- -------------------------------------------------- 3 /dev/rasm-diske 4 /dev/rasm-diskf 1 /dev/rasm-diskc ?????ASM SPFILE??????(redundancy=high),????? /dev/rasm-diskc?AU=39?/dev/rasm-diske AU=35?/dev/rasm-diskf AU=35? ????kfed?????????ASM DISK?header: [grid@maclean1 wallets]$ kfed read /dev/rasm-diske|grep spfile kfdhdb.spfile: 35 ; 0x0f4: 0x00000023 [grid@maclean1 wallets]$ kfed read /dev/rasm-diskc|grep spfile kfdhdb.spfile: 39 ; 0x0f4: 0x00000027 [grid@maclean1 wallets]$ kfed read /dev/rasm-diskf|grep spfile kfdhdb.spfile: 35 ; 0x0f4: 0x00000023 ????ASM disk header?kfdhdb.spfile??ASM SPFILE???DISK??AU NUMBER????, ASM???????????GPNP PROFILE?? DiscoveryString?????????,????ASM disk header?????kfdhdb.spfile??????,?????MOUNT DISKGROUP??????ASM SPFILE,?????ASM, ?????????????????

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  • Custom rails route problem with 2.3.8 and Mongrel

    - by CHsurfer
    I have a controller called 'exposures' which I created automatically with the script/generate scaffold call. The scaffold pages work fine. I created a custom action called 'test' in the exposures controller. When I try to call the page (http://127.0.0.1:3000/exposures/test/1) I get a blank, white screen with no text at all in the source. I am using Rails 2.3.8 and mongrel in the development environment. There are no entries in development.log and the console that was used to open mongrel has the following error: You might have expected an instance of Array. The error occurred while evaluating nil.split D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/cgi_process.rb:52:in dispatch_cgi' D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:101:in dispatch_cgi' D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:27:in dispatch' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:76:in process' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:74:in synchronize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:74:in process' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:159:in process_client' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:158:in each' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:158:in process_client' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in initialize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in new' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in initialize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in new' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:282:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:281:in each' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:281:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:128:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/command.rb:212:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:281 D:/Rails/ruby/bin/mongrel_rails:19:in load' D:/Rails/ruby/bin/mongrel_rails:19 Here is the exposures_controller code: class ExposuresController < ApplicationController # GET /exposures # GET /exposures.xml def index @exposures = Exposure.all respond_to do |format| format.html # index.html.erb format.xml { render :xml => @exposures } end end #/exposure/graph/1 def graph @exposure = Exposure.find(params[:id]) project_name = @exposure.tender.project.name group_name = @exposure.tender.user.group.name tender_desc = @exposure.tender.description direction = "Cash Out" direction = "Cash In" if @exposure.supply currency_1_and_2 = "#{@exposure.currency_in} = #{@exposure.currency_out}" title = "#{project_name}:#{group_name}:#{tender_desc}/n" title += "#{direction}:#{currency_1_and_2}" factors = Array.new carrieds = Array.new days = Array.new @exposure.rates.each do |r| factors << r.factor carrieds << r.carried days << r.day.to_s end max = (factors+carrieds).max min = (factors+carrieds).min g = Graph.new g.title(title, '{font-size: 12px;}') g.set_data(factors) g.line_hollow(2, 4, '0x80a033', 'Bounces', 10) g.set_x_labels(days) g.set_x_label_style( 10, '#CC3399', 2 ); g.set_y_min(min*0.9) g.set_y_max(max*1.1) g.set_y_label_steps(5) render :text = g.render end def test render :text = "this works" end # GET /exposures/1 # GET /exposures/1.xml def show @exposure = Exposure.find(params[:id]) @graph = open_flash_chart_object(700,250, "/exposures/graph/#{@exposure.id}") #@graph = "/exposures/graph/#{@exposure.id}" respond_to do |format| format.html # show.html.erb format.xml { render :xml => @exposure } end end # GET /exposures/new # GET /exposures/new.xml def new @exposure = Exposure.new respond_to do |format| format.html # new.html.erb format.xml { render :xml => @exposure } end end # GET /exposures/1/edit def edit @exposure = Exposure.find(params[:id]) end # POST /exposures # POST /exposures.xml def create @exposure = Exposure.new(params[:exposure]) respond_to do |format| if @exposure.save flash[:notice] = 'Exposure was successfully created.' format.html { redirect_to(@exposure) } format.xml { render :xml => @exposure, :status => :created, :location => @exposure } else format.html { render :action => "new" } format.xml { render :xml => @exposure.errors, :status => :unprocessable_entity } end end end # PUT /exposures/1 # PUT /exposures/1.xml def update @exposure = Exposure.find(params[:id]) respond_to do |format| if @exposure.update_attributes(params[:exposure]) flash[:notice] = 'Exposure was successfully updated.' format.html { redirect_to(@exposure) } format.xml { head :ok } else format.html { render :action => "edit" } format.xml { render :xml => @exposure.errors, :status => :unprocessable_entity } end end end # DELETE /exposures/1 # DELETE /exposures/1.xml def destroy @exposure = Exposure.find(params[:id]) @exposure.destroy respond_to do |format| format.html { redirect_to(exposures_url) } format.xml { head :ok } end end end Clever readers will notice the 'graph' action. This is what I really want to work, but if I can't even get the test action working, then I'm sure I have no chance. Any ideas? I have restarted mongrel a few times with no change. Here is the output of Rake routes (but I don't believe this is the problem. The error would be in the form of and HTML error response). D:\Rails\rails_apps\fxrake routes (in D:/Rails/rails_apps/fx) DEPRECATION WARNING: Rake tasks in vendor/plugins/open_flash_chart/tasks are deprecated. Use lib/tasks instead. (called from D:/ by/gems/1.8/gems/rails-2.3.8/lib/tasks/rails.rb:10) rates GET /rates(.:format) {:controller="rates", :action="index"} POST /rates(.:format) {:controller="rates", :action="create"} new_rate GET /rates/new(.:format) {:controller="rates", :action="new"} edit_rate GET /rates/:id/edit(.:format) {:controller="rates", :action="edit"} rate GET /rates/:id(.:format) {:controller="rates", :action="show"} PUT /rates/:id(.:format) {:controller="rates", :action="update"} DELETE /rates/:id(.:format) {:controller="rates", :action="destroy"} tenders GET /tenders(.:format) {:controller="tenders", :action="index"} POST /tenders(.:format) {:controller="tenders", :action="create"} new_tender GET /tenders/new(.:format) {:controller="tenders", :action="new"} edit_tender GET /tenders/:id/edit(.:format) {:controller="tenders", :action="edit"} tender GET /tenders/:id(.:format) {:controller="tenders", :action="show"} PUT /tenders/:id(.:format) {:controller="tenders", :action="update"} DELETE /tenders/:id(.:format) {:controller="tenders", :action="destroy"} exposures GET /exposures(.:format) {:controller="exposures", :action="index"} POST /exposures(.:format) {:controller="exposures", :action="create"} new_exposure GET /exposures/new(.:format) {:controller="exposures", :action="new"} edit_exposure GET /exposures/:id/edit(.:format) {:controller="exposures", :action="edit"} exposure GET /exposures/:id(.:format) {:controller="exposures", :action="show"} PUT /exposures/:id(.:format) {:controller="exposures", :action="update"} DELETE /exposures/:id(.:format) {:controller="exposures", :action="destroy"} currencies GET /currencies(.:format) {:controller="currencies", :action="index"} POST /currencies(.:format) {:controller="currencies", :action="create"} new_currency GET /currencies/new(.:format) {:controller="currencies", :action="new"} edit_currency GET /currencies/:id/edit(.:format) {:controller="currencies", :action="edit"} currency GET /currencies/:id(.:format) {:controller="currencies", :action="show"} PUT /currencies/:id(.:format) {:controller="currencies", :action="update"} DELETE /currencies/:id(.:format) {:controller="currencies", :action="destroy"} projects GET /projects(.:format) {:controller="projects", :action="index"} POST /projects(.:format) {:controller="projects", :action="create"} new_project GET /projects/new(.:format) {:controller="projects", :action="new"} edit_project GET /projects/:id/edit(.:format) {:controller="projects", :action="edit"} project GET /projects/:id(.:format) {:controller="projects", :action="show"} PUT /projects/:id(.:format) {:controller="projects", :action="update"} DELETE /projects/:id(.:format) {:controller="projects", :action="destroy"} groups GET /groups(.:format) {:controller="groups", :action="index"} POST /groups(.:format) {:controller="groups", :action="create"} new_group GET /groups/new(.:format) {:controller="groups", :action="new"} edit_group GET /groups/:id/edit(.:format) {:controller="groups", :action="edit"} group GET /groups/:id(.:format) {:controller="groups", :action="show"} PUT /groups/:id(.:format) {:controller="groups", :action="update"} DELETE /groups/:id(.:format) {:controller="groups", :action="destroy"} users GET /users(.:format) {:controller="users", :action="index"} POST /users(.:format) {:controller="users", :action="create"} new_user GET /users/new(.:format) {:controller="users", :action="new"} edit_user GET /users/:id/edit(.:format) {:controller="users", :action="edit"} user GET /users/:id(.:format) {:controller="users", :action="show"} PUT /users/:id(.:format) {:controller="users", :action="update"} DELETE /users/:id(.:format) {:controller="users", :action="destroy"} /:controller/:action/:id /:controller/:action/:id(.:format) D:\Rails\rails_apps\fxrails -v Rails 2.3.8 Thanks in advance for the help -Jon

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  • Whats wrong with my triple DES wrapper??

    - by Chen Kinnrot
    it seems that my code adds 6 bytes to the result file after encrypt decrypt is called.. i tries it on a mkv file.. please help here is my code class TripleDESCryptoService : IEncryptor, IDecryptor { public void Encrypt(string inputFileName, string outputFileName, string key) { EncryptFile(inputFileName, outputFileName, key); } public void Decrypt(string inputFileName, string outputFileName, string key) { DecryptFile(inputFileName, outputFileName, key); } static void EncryptFile(string inputFileName, string outputFileName, string sKey) { var outFile = new FileStream(outputFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite); // The chryptographic service provider we're going to use var cryptoAlgorithm = new TripleDESCryptoServiceProvider(); SetKeys(cryptoAlgorithm, sKey); // This object links data streams to cryptographic values var cryptoStream = new CryptoStream(outFile, cryptoAlgorithm.CreateEncryptor(), CryptoStreamMode.Write); // This stream writer will write the new file var encryptionStream = new BinaryWriter(cryptoStream); // This stream reader will read the file to encrypt var inFile = new FileStream(inputFileName, FileMode.Open, FileAccess.Read); var readwe = new BinaryReader(inFile); // Loop through the file to encrypt, line by line var date = readwe.ReadBytes((int)readwe.BaseStream.Length); // Write to the encryption stream encryptionStream.Write(date); // Wrap things up inFile.Close(); encryptionStream.Flush(); encryptionStream.Close(); } private static void SetKeys(SymmetricAlgorithm algorithm, string key) { var keyAsBytes = Encoding.ASCII.GetBytes(key); algorithm.IV = keyAsBytes.Take(algorithm.IV.Length).ToArray(); algorithm.Key = keyAsBytes.Take(algorithm.Key.Length).ToArray(); } static void DecryptFile(string inputFilename, string outputFilename, string sKey) { // The encrypted file var inFile = File.OpenRead(inputFilename); // The decrypted file var outFile = new FileStream(outputFilename, FileMode.OpenOrCreate, FileAccess.ReadWrite); // Prepare the encryption algorithm and read the key from the key file var cryptAlgorithm = new TripleDESCryptoServiceProvider(); SetKeys(cryptAlgorithm, sKey); // The cryptographic stream takes in the encrypted file var encryptionStream = new CryptoStream(inFile, cryptAlgorithm.CreateDecryptor(), CryptoStreamMode.Read); // Write the new unecrypted file var cleanStreamReader = new BinaryReader(encryptionStream); var cleanStreamWriter = new BinaryWriter(outFile); cleanStreamWriter.Write(cleanStreamReader.ReadBytes((int)inFile.Length)); cleanStreamWriter.Close(); outFile.Close(); cleanStreamReader.Close(); } }

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  • Encrypt a hex string in java.

    - by twintwins
    I would like to ask for any suggestions about my problem. I need to encrypt a hexadecimal string. I must not to use the built-in functions of java because it doesn't work in my server. In short, I have to hard code an algorithm or any means of encrypting the message. Anyone who could help me with this? thanks a lot! here is the code. public Encrypt(SecretKey key, String algorithm) { try { ecipher = Cipher.getInstance(algorithm); dcipher = Cipher.getInstance(algorithm); ecipher.init(Cipher.ENCRYPT_MODE, key); dcipher.init(Cipher.DECRYPT_MODE, key); } catch (NoSuchPaddingException e) { System.out.println("EXCEPTION: NoSuchPaddingException"); } catch (NoSuchAlgorithmException e) { System.out.println("EXCEPTION: NoSuchAlgorithmException"); } catch (InvalidKeyException e) { System.out.println("EXCEPTION: InvalidKeyException"); } } public void useSecretKey(String secretString) { try { SecretKey desKey = KeyGenerator.getInstance("DES").generateKey(); SecretKey blowfishKey = KeyGenerator.getInstance("Blowfish").generateKey(); SecretKey desedeKey = KeyGenerator.getInstance("DESede").generateKey(); Encrypt desEncrypter = new Encrypt(desKey, desKey.getAlgorithm()); Encrypt blowfishEncrypter = new Encrypt(blowfishKey, blowfishKey.getAlgorithm()); Encrypt desedeEncrypter = new Encrypt(desedeKey, desedeKey.getAlgorithm()); desEncrypted = desEncrypter.encrypt(secretString); blowfishEncrypted = blowfishEncrypter.encrypt(secretString); desedeEncrypted = desedeEncrypter.encrypt(secretString); } catch (NoSuchAlgorithmException e) {} } those are the methods i used. no problem if it is run as an application but then when i put it to my server which is the glassfish server an exception occured and it says no such algorithm.

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  • WPF: How to refresh a window while debugging?

    - by Qwertie
    I am debugging an algorithm that is being represented by a set of ViewModels. In order to debug this algorithm I would like to redraw the View while stepping through part of the algorithm. Is this possible? (I would prefer to just repaint, not do what they call "DoEvents" to process all events.)

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  • Can I use the browser's word-wrapping from JavaScript?

    - by Max
    I have some text in a div. It can be any Unicode text under the sun, including Chinese, Japanese, and Korean. Now, I need to take this text and word-wrap it in JavaScript in some efficient but correct manner. (Because I need to make each line start with "" in a textarea.) Browsers have an implementation of the Unicode Word Wrap algorithm, as is evidenced by word-wrapping Unicode text in a with CSS. (At least, Firefox has such an algorithm, and I suspect other browsers do as well.) What I need is some way for JavaScript to use the same word-wrapping algorithm, so that I can properly wrap and then "quote" Unicode text. Is there any way for JavaScript to use the browser's word-wrapping algorithm, or to know where text has been line-broken in a div or any other element?

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  • Parse youtube links PHP

    - by Isis
    Hello 34|http://v19.lscache8.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id,expire,ip,ipbits,itag,algorithm,burst,factor,oc:U0dWRlZUVF9FSkNNNl9OTlhF&fexp=902210&algorithm=throttle-factor&itag=34&ipbits=0&burst=40&sver=3&expire=1271696400&key=yt1&signature=583C4A85FA65B6B9782B8B4B5E1F1C08D9EADCA3.5B28033470580BC52EB92A1CB71DBAFE0C4A2A8D&factor=1.25&id=cf3cec58d98073dc,5|http://v24.lscache4.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id,expire,ip,ipbits,itag,algorithm,burst,factor,oc:U0dWRlZUVF9FSkNNNl9OTlhF&fexp=902210&algorithm=throttle-factor&itag=5&ipbits=0&burst=40&sver=3&expire=1271696400&key=yt1&signature=7B74075BAA26B05A028B2219FD52D7A45197F555.A8878413DC7BB3FFAB0C9219CBD3FCDD7221B440&factor=1.25&id=cf3cec58d98073dc How to parse this text for: 34 http://... (before ,5|) 5 http://... to end Previously it was done so: if (preg_match_all('#|(.*?),#', $urlmap, $b)) { } Sorry for baaaaad english

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  • Randomly sorting an array

    - by Cam
    Does there exist an algorithm which, given an ordered list of symbols {a1, a2, a3, ..., ak}, produces in O(n) time a new list of the same symbols in a random order without bias? "Without bias" means the probability that any symbol s will end up in some position p in the list is 1/k. Assume it is possible to generate a non-biased integer from 1-k inclusive in O(1) time. Also assume that O(1) element access/mutation is possible, and that it is possible to create a new list of size k in O(k) time. In particular, I would be interested in a 'generative' algorithm. That is, I would be interested in an algorithm that has O(1) initial overhead, and then produces a new element for each slot in the list, taking O(1) time per slot. If no solution exists to the problem as described, I would still like to know about solutions that do not meet my constraints in one or more of the following ways (and/or in other ways if necessary): the time complexity is worse than O(n). the algorithm is biased with regards to the final positions of the symbols. the algorithm is not generative. I should add that this problem appears to be the same as the problem of randomly sorting the integers from 1-k, since we can sort the list of integers from 1-k and then for each integer i in the new list, we can produce the symbol ai.

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  • Symmetric Encryption: Performance Questions

    - by cam
    Does the performance of a symmetric encryption algorithm depend on the amount of data being encrypted? Suppose I have about 1000 bytes I need to send over the network rapidly, is it better to encrypt 50 bytes of data 20 times, or 1000 bytes at once? Which will be faster? Does it depend on the algorithm used? If so, what's the highest performing, most secure algorithm for amounts of data under 512 bytes?

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  • Allocation of IP Address in Ad hoc systems

    - by Kasturi
    Me and my friends play Age of Empires every weekend and create an Ad-hoc network each time before playing. But each time we all get the SAME IP Address even if a new ad-hoc network is created. Is this something to do with the Game's algorithm or does the laptop remember our previous IP Address. EDIT: What is the algorithm that is used to distribute the IP Addresses? If the algorithm uses random function how come same IP addresses are being allocated.

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  • Which of these methods provides for the fastest page loading?

    - by chromedude
    I am building a database in MySQL that will be accessed by PHP scripts. I have a table that is the activity stream. This includes everything that goes on on the website (following of many different things, liking, upvoting etc.). From this activity stream I am going to run an algorithm for each user depending on their activity and display relevant activity. Should I create another table that stores the activity for each user once the algorithm has been run on the activity or should I run the algorithm on the activity table every time the user accesses the site? UPDATE:(this is what is above except rephrased hopefully in an easier to understand way) I have a database table called activity. This table creates a new row every time an action is performed by a user on the website. Every time a user logs in I am going to run an algorithm on the new rows (since the users last login) in the table (activity) that apply to them. For example if the user is following a user who upvoted a post in the activity stream that post will be displayed when the user logs in. I want the ability for the user to be able to access previous content applying to them. Would it be easiest to create another table that saved the rows that have already been run over with the algorithm except attached to individual users names? (a row can apply to multiple different users)

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  • How can I use multithreading in a Windows Forms application to update a progress bar?

    - by Steve Syfuhs
    There are two objects. The Windows Form with a button and a progress bar, and another object that handles an algorithm. In the algorithm object there is an event, and a property. The event is ProgressChanged, and the property is Progress (which is an int). In the calling window, the button starts off a set of steps in the algorithm object. As each step (or substeps) occurs, the ProgressChanged event fires, and in the window there is an event handler that essentially increments the progress bar relative to the Progress property. The problem I am running into is that because the algorithm has a possibility (and high liklihood) of running a relatively long time, I need to move it into it's own background thread and push the event back up to the window. My issue is that I'm not completely sure what I'm doing when it comes to multi-threading. I've looked at Control.Invoke and I'm a little lost. Can someone point me in the right direction?

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  • Sort objects and polymorphism

    - by ritmbo
    Suppose I have a class A. And B and C are child of A. Class A has a generic algorithm for sorting arrays of type A, so that I could use it for B and C without writing again the algorithm for each. In the algorithm, sometimes I have to swap. The problem is that I can only see the objects as type A, and if I do: A aux = array[i] array[i] = array[j] array[j] = aux I think I have a problem. Because array[i], maybe its of type B, and aux is of type A, so I think I'm losing information. I'm sure u understand this situation... how can I sort a generic array of objects using a father method algorithm?

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