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  • Find a regular expression that matches a string?

    - by Mirai
    I need a model for finding all of the regular expressions that would match a particular string. Basically, I need an algorithm for doing what I do to generate a regex search string from some pattern. My purpose for this to create a list of potential regular expressions from a selection of text and order that list from least specific (i.e. string of characters with abitrary length) to most specific (i.e. the string itself) to be used in text editor.

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  • extract all urls from a string

    - by codemonkey12
    I have a string of text that contains html, and I need to extract each url (most likely in img or a tags) to create a generic list of string objects. Is there an easy way to do this or will I have to resort to regular expressions? If I have to resort to regular expressions, would you mind helping me out with that as well? :)

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  • In elisp is there a difference between the regex [\\]documentclass and \\documentclass?

    - by mcheema
    I was playing around with the rx function for generating regular expressions from sexps in ELISP but couldn't figure out how to generate the regular expression "\\documentclass" for use in org-export-latex-classes: (rx "\\documentclass") (rx "\\" "documentclass") (rx (char "\\") "documentclass") Which when evaluated give respectively the following outputs: "\\\\documentclass" "\\\\documentclass" "[\\]documentclass" Is "\\documentclass" equivalent to "[\\]documentclass"?---I think it is, but am not sure. Can I generate the former using rx? Edit: Whilst the question was valid I realize my motivation was not; because org-export-latex-classes use strings not regular expressions.

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  • How to match parameter names in an expression?

    - by burak ozdogan
    Hi, I have a set of expressions representing some formula with some parameters inside. Like: [parameter1] * [parameter2] * [multiplier] And many others like this. I want to use a regular expression so that I can get a list of strings (List<string>) which will have the following inside: [paramter1] [paramter2] [multiplier] I am not using regular expressions so often; if you have already used something like this I would appreciate if you can share. Thanks!

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  • Xpath visualization

    - by JavaRocky
    I am looking for a XML tool which does the following things. Allows me to enter xpath expressions and highlights the nodes selected Assists me in creating complex xpath expressions. What are other people using out there? I've used something from source forge but it only selects one matched node.

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  • ASP.NET MVC 3: Implicit and Explicit code nuggets with Razor

    - by ScottGu
    This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (Dec 15th) Implicit and Explicit code nuggets with Razor (today) In today’s post I’m going to discuss how Razor enables you to both implicitly and explicitly define code nuggets within your view templates, and walkthrough some code examples of each of them.  Fluid Coding with Razor ASP.NET MVC 3 ships with a new view-engine option called “Razor” (in addition to the existing .aspx view engine).  You can learn more about Razor, why we are introducing it, and the syntax it supports from my Introducing Razor blog post. Razor minimizes the number of characters and keystrokes required when writing a view template, and enables a fast, fluid coding workflow. Unlike most template syntaxes, you do not need to interrupt your coding to explicitly denote the start and end of server blocks within your HTML. The Razor parser is smart enough to infer this from your code. This enables a compact and expressive syntax which is clean, fast and fun to type. For example, the Razor snippet below can be used to iterate a collection of products and output a <ul> list of product names that link to their corresponding product pages: When run, the above code generates output like below: Notice above how we were able to embed two code nuggets within the content of the foreach loop.  One of them outputs the name of the Product, and the other embeds the ProductID within a hyperlink.  Notice that we didn’t have to explicitly wrap these code-nuggets - Razor was instead smart enough to implicitly identify where the code began and ended in both of these situations.  How Razor Enables Implicit Code Nuggets Razor does not define its own language.  Instead, the code you write within Razor code nuggets is standard C# or VB.  This allows you to re-use your existing language skills, and avoid having to learn a customized language grammar. The Razor parser has smarts built into it so that whenever possible you do not need to explicitly mark the end of C#/VB code nuggets you write.  This makes coding more fluid and productive, and enables a nice, clean, concise template syntax.  Below are a few scenarios that Razor supports where you can avoid having to explicitly mark the beginning/end of a code nugget, and instead have Razor implicitly identify the code nugget scope for you: Property Access Razor allows you to output a variable value, or a sub-property on a variable that is referenced via “dot” notation: You can also use “dot” notation to access sub-properties multiple levels deep: Array/Collection Indexing: Razor allows you to index into collections or arrays: Calling Methods: Razor also allows you to invoke methods: Notice how for all of the scenarios above how we did not have to explicitly end the code nugget.  Razor was able to implicitly identify the end of the code block for us. Razor’s Parsing Algorithm for Code Nuggets The below algorithm captures the core parsing logic we use to support “@” expressions within Razor, and to enable the implicit code nugget scenarios above: Parse an identifier - As soon as we see a character that isn't valid in a C# or VB identifier, we stop and move to step 2 Check for brackets - If we see "(" or "[", go to step 2.1., otherwise, go to step 3  Parse until the matching ")" or "]" (we track nested "()" and "[]" pairs and ignore "()[]" we see in strings or comments) Go back to step 2 Check for a "." - If we see one, go to step 3.1, otherwise, DO NOT ACCEPT THE "." as code, and go to step 4 If the character AFTER the "." is a valid identifier, accept the "." and go back to step 1, otherwise, go to step 4 Done! Differentiating between code and content Step 3.1 is a particularly interesting part of the above algorithm, and enables Razor to differentiate between scenarios where an identifier is being used as part of the code statement, and when it should instead be treated as static content: Notice how in the snippet above we have ? and ! characters at the end of our code nuggets.  These are both legal C# identifiers – but Razor is able to implicitly identify that they should be treated as static string content as opposed to being part of the code expression because there is whitespace after them.  This is pretty cool and saves us keystrokes. Explicit Code Nuggets in Razor Razor is smart enough to implicitly identify a lot of code nugget scenarios.  But there are still times when you want/need to be more explicit in how you scope the code nugget expression.  The @(expression) syntax allows you to do this: You can write any C#/VB code statement you want within the @() syntax.  Razor will treat the wrapping () characters as the explicit scope of the code nugget statement.  Below are a few scenarios where we could use the explicit code nugget feature: Perform Arithmetic Calculation/Modification: You can perform arithmetic calculations within an explicit code nugget: Appending Text to a Code Expression Result: You can use the explicit expression syntax to append static text at the end of a code nugget without having to worry about it being incorrectly parsed as code: Above we have embedded a code nugget within an <img> element’s src attribute.  It allows us to link to images with URLs like “/Images/Beverages.jpg”.  Without the explicit parenthesis, Razor would have looked for a “.jpg” property on the CategoryName (and raised an error).  By being explicit we can clearly denote where the code ends and the text begins. Using Generics and Lambdas Explicit expressions also allow us to use generic types and generic methods within code expressions – and enable us to avoid the <> characters in generics from being ambiguous with tag elements. One More Thing….Intellisense within Attributes We have used code nuggets within HTML attributes in several of the examples above.  One nice feature supported by the Razor code editor within Visual Studio is the ability to still get VB/C# intellisense when doing this. Below is an example of C# code intellisense when using an implicit code nugget within an <a> href=”” attribute: Below is an example of C# code intellisense when using an explicit code nugget embedded in the middle of a <img> src=”” attribute: Notice how we are getting full code intellisense for both scenarios – despite the fact that the code expression is embedded within an HTML attribute (something the existing .aspx code editor doesn’t support).  This makes writing code even easier, and ensures that you can take advantage of intellisense everywhere. Summary Razor enables a clean and concise templating syntax that enables a very fluid coding workflow.  Razor’s ability to implicitly scope code nuggets reduces the amount of typing you need to perform, and leaves you with really clean code. When necessary, you can also explicitly scope code expressions using a @(expression) syntax to provide greater clarity around your intent, as well as to disambiguate code statements from static markup. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • Using delegates in C# (Part 2)

    - by rajbk
    Part 1 of this post can be read here. We are now about to see the different syntaxes for invoking a delegate and some c# syntactic sugar which allows you to code faster. We have the following console application. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: Operation op1 = new Operation(Division); 9: double result = op1.Invoke(10, 5); 10: 11: Console.WriteLine(result); 12: Console.ReadLine(); 13: } 14: 15: static double Division(double x, double y) { 16: return x / y; 17: } 18: } Line 1 defines a delegate type called Operation with input parameters (double x, double y) and a return type of double. On Line 8, we create an instance of this delegate and set the target to be a static method called Division (Line 15) On Line 9, we invoke the delegate (one entry in the invocation list). The program outputs 5 when run. The language provides shortcuts for creating a delegate and invoking it (see line 9 and 11). Line 9 is a syntactical shortcut for creating an instance of the Delegate. The C# compiler will infer on its own what the delegate type is and produces intermediate language that creates a new instance of that delegate. Line 11 uses a a syntactical shortcut for invoking the delegate by removing the Invoke method. The compiler sees the line and generates intermediate language which invokes the delegate. When this code is compiled, the generated IL will look exactly like the IL of the compiled code above. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //shortcut constructor syntax 9: Operation op1 = Division; 10: //shortcut invoke syntax 11: double result = op1(10, 2); 12: 13: Console.WriteLine(result); 14: Console.ReadLine(); 15: } 16: 17: static double Division(double x, double y) { 18: return x / y; 19: } 20: } C# 2.0 introduced Anonymous Methods. Anonymous methods avoid the need to create a separate method that contains the same signature as the delegate type. Instead you write the method body in-line. There is an interesting fact about Anonymous methods and closures which won’t be covered here. Use your favorite search engine ;-)We rewrite our code to use anonymous methods (see line 9): 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //Anonymous method 9: Operation op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } We could rewrite our delegate to be of a generic type like so (see line 2 and line 9). You will see why soon. 1: //Generic delegate 2: public delegate T Operation<T>(T x, T y); 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: Operation<double> op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } The .NET 3.5 framework introduced a whole set of predefined delegates for us including public delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2); Our code can be modified to use this delegate instead of the one we declared. Our delegate declaration has been removed and line 7 has been changed to use the Func delegate type. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //Func is a delegate defined in the .NET 3.5 framework 7: Func<double, double, double> op1 = delegate (double x, double y) { 8: return x / y; 9: }; 10: double result = op1(10, 2); 11: 12: Console.WriteLine(result); 13: Console.ReadLine(); 14: } 15: 16: static double Division(double x, double y) { 17: return x / y; 18: } 19: } .NET 3.5 also introduced lambda expressions. A lambda expression is an anonymous function that can contain expressions and statements, and can be used to create delegates or expression tree types. We change our code to use lambda expressions. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //lambda expression 7: Func<double, double, double> op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } C# 3.0 introduced the keyword var (implicitly typed local variable) where the type of the variable is inferred based on the type of the associated initializer expression. We can rewrite our code to use var as shown below (line 7).  The implicitly typed local variable op1 is inferred to be a delegate of type Func<double, double, double> at compile time. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //implicitly typed local variable 7: var op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } You have seen how we can write code in fewer lines by using a combination of the Func delegate type, implicitly typed local variables and lambda expressions.

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  • Get Exchange Online Mailbox Size in GB

    - by Brian Jackett
    As mentioned in my previous post I was recently working with a customer to get started with Exchange Online PowerShell commandlets.  In this post I wanted to follow up and show one example of a difference in output from commandlets in Exchange 2010 on-premises vs. Exchange Online.   Problem    The customer was interested in getting the size of mailboxes in GB.  For Exchange on-premises this is fairly easy.  A fellow PFE Gary Siepser wrote an article explaining how to accomplish this (click here).  Note that Gary’s script will not work when remoting from a local machine that doesn’t have the Exchange object model installed.  A similar type of scenario exists if you are executing PowerShell against Exchange Online.  The data type for TotalItemSize  being returned (ByteQuantifiedSize) exists in the Exchange namespace.  If the PowerShell session doesn’t have access to that namespace (or hasn’t loaded it) PowerShell works with an approximation of that data type.    The customer found a sample script on this TechNet article that they attempted to use (minor edits by me to fit on page and remove references to deleted item size.)   Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics | Select DisplayName,StorageLimitStatus, ` @{name="TotalItemSize (MB)"; expression={[math]::Round( ` ($_.TotalItemSize.Split("(")[1].Split(" ")[0].Replace(",","")/1MB),2)}}, ` ItemCount | Sort "TotalItemSize (MB)" -Descending | Export-CSV "C:\My Documents\All Mailboxes.csv" -NoTypeInformation     The script is targeted to Exchange 2010 but fails for Exchange Online.  In Exchange Online when referencing the TotalItemSize property though it does not have a Split method which ultimately causes the script to fail.   Solution    A simple solution would be to add a call to the ToString method off of the TotalItemSize property (in bold on line 5 below).   Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics | Select DisplayName,StorageLimitStatus, ` @{name="TotalItemSize (MB)"; expression={[math]::Round( ` ($_.TotalItemSize.ToString().Split("(")[1].Split(" ")[0].Replace(",","")/1MB),2)}}, ` ItemCount | Sort "TotalItemSize (MB)" -Descending | Export-CSV "C:\My Documents\All Mailboxes.csv" -NoTypeInformation      This fixes the script to run but the numerous string replacements and splits are an eye sore to me.  I attempted to simplify the string manipulation with a regular expression (more info on regular expressions in PowerShell click here).  The result is a workable script that does one nice feature of adding a new member to the mailbox statistics called TotalItemSizeInBytes.  With this member you can then convert into any byte level (KB, MB, GB, etc.) that suits your needs.  You can download the full version of this script below (includes commands to connect to Exchange Online session). $UserMailboxStats = Get-Mailbox -RecipientTypeDetails UserMailbox ` -ResultSize Unlimited | Get-MailboxStatistics $UserMailboxStats | Add-Member -MemberType ScriptProperty -Name TotalItemSizeInBytes ` -Value {$this.TotalItemSize -replace "(.*\()|,| [a-z]*\)", ""} $UserMailboxStats | Select-Object DisplayName,@{Name="TotalItemSize (GB)"; ` Expression={[math]::Round($_.TotalItemSizeInBytes/1GB,2)}}   Conclusion    Moving from on-premises to the cloud with PowerShell (and PowerShell remoting in general) can sometimes present some new challenges due to what you have access to.  This means that you must always test your code / scripts.  I still believe that not having to physically RDP to a server is a huge gain over some of the small hurdles you may encounter during the transition.  Scripting is the future of administration and makes you more valuable.  Hopefully this script and the concepts presented help you be a better admin / developer.         -Frog Out     Links The Get-MailboxStatistics Cmdlet, the TotalitemSize Property, and that pesky little “b” http://blogs.technet.com/b/gary/archive/2010/02/20/the-get-mailboxstatistics-cmdlet-the-totalitemsize-property-and-that-pesky-little-b.aspx   View Mailbox Sizes and Mailbox Quotas Using Windows PowerShell http://technet.microsoft.com/en-us/exchangelabshelp/gg576861#ViewAllMailboxes   Regular Expressions with Windows PowerShell http://www.regular-expressions.info/powershell.html   “I don’t always test my code…” image http://blogs.pinkelephant.com/images/uploads/conferences/I-dont-always-test-my-code-But-when-I-do-I-do-it-in-production.jpg   The One Thing: Brian Jackett and SharePoint 2010 http://www.youtube.com/watch?v=Sg_h66HMP9o

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  • Java how can I add an accented "e" to a string?

    - by behrk2
    Hello, With the help of tucuxi from the existing post Java remove HTML from String without regular expressions I have built a method that will parse out any basic HTML tags from a string. Sometimes, however, the original string contains html hexadecimal characters like é (which is an accented e). I have started to add functionality which will translate these escaped characters into real characters. You're probably asking: Why not use regular expressions? Or a third party library? Unfortunately I cannot, as I am developing on a BlackBerry platform which does not support regular expressions and I have never been able to successfully add a third party library to my project. So, I have gotten to the point where any é is replaced with "e". My question now is, how do I add an actual 'accented e' to a string? Here is my code: public static String removeHTML(String synopsis) { char[] cs = synopsis.toCharArray(); String sb = new String(); boolean tag = false; for (int i = 0; i < cs.length; i++) { switch (cs[i]) { case '<': if (!tag) { tag = true; break; } case '>': if (tag) { tag = false; break; } case '&': char[] copyTo = new char[7]; System.arraycopy(cs, i, copyTo, 0, 7); String result = new String(copyTo); if (result.equals("&#x00E9")) { sb += "e"; } i += 7; break; default: if (!tag) sb += cs[i]; } } return sb.toString(); } Thanks!

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  • What's wrong with this regex (VBScript/Javascript flavor)

    - by OtherMichael
    I'm trying to run a regular expression in VBA code that uses Microsoft VBScript Regular Expressions 5.5 (should be the same as JavaScript regex) regex: ^[0-9A-Z]?[0-9A-Z]{3}[A-Z]?([0-9A-Z]{6})-?([0-9])?$ input: X123A1234567 match: 123456 the six characters I'm interested in give a good match of 123456, ignoring the last (check) digit. Perfect. (The check digit is captured, but it's not a major concern to me). But when BOTH the optional portions are gone (they are optional) the match grabs the last digit GOOD input: 123A1234567 match: 123456 Leave in the optional middle alpha, take out the optional leading alpha, and we still get the good match of 123456 GOOD input: X1231234567 match: 123456 Leave in the optional leading alpha, take out the middle optional alpha, and we still get a good match of 123456 BAD input: 1231234567 match: 234567 Take out BOTH optional alphas, and we get a bad match of 234567 Have a looksee @ the regex testers on http://www.regular-expressions.info/javascriptexample.html or http://www.regular-expressions.info/vbscriptexample.html What am I missing, here? How can I get the regex to ignore the last digit when both optional alphas are missing? The regex is used to feed a lookup system, so that no matter what format the input data, we can match to a complete value.

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  • "User Friendly" .net compatible Regex/Text matching tools?

    - by Binary Worrier
    Currently in our software we provide a hook where we call a DLL built by our clients to parse information out of documents we are processing (the DLL takes in some text (or a file) and returns a list of name/value pairs). e.g. We're given a Word doc or Text file to Archive. We do various things to the file, and call a DLL that will return "pertinent" information about the file. Among other things we store that "pertinent" data for posterity. What is considered "pertinent" depends on the client and the type of the document, we don't care, we get it and store it. I've been asked to develop a user friendly "something" that will allow a non-programmer user to "configure" how to get this data from a plain text document (<humor>The user story ends with the helpful suggestion/query "We could use regex for this?"</humor>) It's safe to assume that a list of regex's isn't going to cut this, I've written some of these parsers for customers, the regex's to do these would be hedious and some of them can't be done by regex's. Also one of the requirements above is "user friendly" which negates anything that has users seeing or editing regex expressions. As you can guess, I don't have a fortune of time to do this, and am wondering is there anything out there that I can plug in to our app that has a nice front end and does exactly what I need? :) No? Whadda mean no! . . . sigh Ok then failing that, anything out there that "visually" builds regex's and/or other pattern matching expressions, and then allows one to run those expressions against some text? The MS BRE will do what I want, but I need something prettier that looks less like code. Thanks guys,

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  • Parsing basic math equations for children's educational software?

    - by Simucal
    Inspired by a recent TED talk, I want to write a small piece of educational software. The researcher created little miniature computers in the shape of blocks called "Siftables". [David Merril, inventor - with Siftables in the background.] There were many applications he used the blocks in but my favorite was when each block was a number or basic operation symbol. You could then re-arrange the blocks of numbers or operation symbols in a line, and it would display an answer on another siftable block. So, I've decided I wanted to implemented a software version of "Math Siftables" on a limited scale as my final project for a CS course I'm taking. What is the generally accepted way for parsing and interpreting a string of math expressions, and if they are valid, perform the operation? Is this a case where I should implement a full parser/lexer? I would imagine interpreting basic math expressions would be a semi-common problem in computer science so I'm looking for the right way to approach this. For example, if my Math Siftable blocks where arranged like: [1] [+] [2] This would be a valid sequence and I would perform the necessary operation to arrive at "3". However, if the child were to drag several operation blocks together such as: [2] [\] [\] [5] It would obviously be invalid. Ultimately, I want to be able to parse and interpret any number of chains of operations with the blocks that the user can drag together. Can anyone explain to me or point me to resources for parsing basic math expressions? I'd prefer as much of a language agnostic answer as possible.

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  • Alternative to using c:out to prevent XSS

    - by lynxforest
    I'm working on preventing cross site scripting (XSS) in a Java, Spring based, Web application. I have already implemented a servlet filter similar to this example http://greatwebguy.com/programming/java/simple-cross-site-scripting-xss-servlet-filter/ which sanitizes all the input into the application. As an extra security measure I would like to also sanitize all output of the application in all JSPs. I have done some research to see how this could be done and found two complementary options. One of them is the use of Spring's defaultHtmlEscape attribute. This was very easy to implement (a few lines in web.xml), and it works great when your output is going through one of spring's tags (ie: message, or form tags). The other option I have found is to not directly use EL expressions such as ${...} and instead use <c:out value="${...}" /> That second approach works perfectly, however due to the size of the application I am working on (200+ JSP files). It is a very cumbersome task to have to replace all inappropriate uses of EL expressions with the c:out tag. Also it would become a cumbersome task in the future to make sure all developers stick to this convention of using the c:out tag (not to mention, how much more unreadable the code would be). Is there alternative way to escape the output of EL expressions that would require fewer code modifications? Thank you in advance.

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  • I need a fast runtime expression parser

    - by Chris Lively
    I need to locate a fast, lightweight expression parser. Ideally I want to pass it a list of name/value pairs (e.g. variables) and a string containing the expression to evaluate. All I need back from it is a true/false value. The types of expressions should be along the lines of: varA == "xyz" and varB==123 Basically, just a simple logic engine whose expression is provided at runtime. UPDATE At minimum it needs to support ==, !=, , =, <, <= Regarding speed, I expect roughly 5 expressions to be executed per request. We'll see somewhere in the vicinity of 100/requests a second. Our current pages tend to execute in under 50ms. Usually there will only be 2 or 3 variables involved in any expression. However, I'll need to load approximately 30 into the parser prior to execution. UPDATE 2012/11/5 Update about performance. We implemented nCalc nearly 2 years ago. Since then we've expanded it's use such that we average 40+ expressions covering 300+ variables on post backs. There are now thousands of post backs occurring per second with absolutely zero performance degradation. We've also extended it to include a handful of additional functions, again with no performance loss. In short, nCalc met all of our needs and exceeded our expectations.

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  • Microsoft Introduces WebMatrix

    - by Rick Strahl
    originally published in CoDe Magazine Editorial Microsoft recently released the first CTP of a new development environment called WebMatrix, which along with some of its supporting technologies are squarely aimed at making the Microsoft Web Platform more approachable for first-time developers and hobbyists. But in the process, it also provides some updated technologies that can make life easier for existing .NET developers. Let’s face it: ASP.NET development isn’t exactly trivial unless you already have a fair bit of familiarity with sophisticated development practices. Stick a non-developer in front of Visual Studio .NET or even the Visual Web Developer Express edition and it’s not likely that the person in front of the screen will be very productive or feel inspired. Yet other technologies like PHP and even classic ASP did provide the ability for non-developers and hobbyists to become reasonably proficient in creating basic web content quickly and efficiently. WebMatrix appears to be Microsoft’s attempt to bring back some of that simplicity with a number of technologies and tools. The key is to provide a friendly and fully self-contained development environment that provides all the tools needed to build an application in one place, as well as tools that allow publishing of content and databases easily to the web server. WebMatrix is made up of several components and technologies: IIS Developer Express IIS Developer Express is a new, self-contained development web server that is fully compatible with IIS 7.5 and based on the same codebase that IIS 7.5 uses. This new development server replaces the much less compatible Cassini web server that’s been used in Visual Studio and the Express editions. IIS Express addresses a few shortcomings of the Cassini server such as the inability to serve custom ISAPI extensions (i.e., things like PHP or ASP classic for example), as well as not supporting advanced authentication. IIS Developer Express provides most of the IIS 7.5 feature set providing much better compatibility between development and live deployment scenarios. SQL Server Compact 4.0 Database access is a key component for most web-driven applications, but on the Microsoft stack this has mostly meant you have to use SQL Server or SQL Server Express. SQL Server Compact is not new-it’s been around for a few years, but it’s been severely hobbled in the past by terrible tool support and the inability to support more than a single connection in Microsoft’s attempt to avoid losing SQL Server licensing. The new release of SQL Server Compact 4.0 supports multiple connections and you can run it in ASP.NET web applications simply by installing an assembly into the bin folder of the web application. In effect, you don’t have to install a special system configuration to run SQL Compact as it is a drop-in database engine: Copy the small assembly into your BIN folder (or from the GAC if installed fully), create a connection string against a local file-based database file, and then start firing SQL requests. Additionally WebMatrix includes nice tools to edit the database tables and files, along with tools to easily upsize (and hopefully downsize in the future) to full SQL Server. This is a big win, pending compatibility and performance limits. In my simple testing the data engine performed well enough for small data sets. This is not only useful for web applications, but also for desktop applications for which a fully installed SQL engine like SQL Server would be overkill. Having a local data store in those applications that can potentially be accessed by multiple users is a welcome feature. ASP.NET Razor View Engine What? Yet another native ASP.NET view engine? We already have Web Forms and various different flavors of using that view engine with Web Forms and MVC. Do we really need another? Microsoft thinks so, and Razor is an implementation of a lightweight, script-only view engine. Unlike the Web Forms view engine, Razor works only with inline code, snippets, and markup; therefore, it is more in line with current thinking of what a view engine should represent. There’s no support for a “page model” or any of the other Web Forms features of the full-page framework, but just a lightweight scripting engine that works with plain markup plus embedded expressions and code. The markup syntax for Razor is geared for minimal typing, plus some progressive detection of where a script block/expression starts and ends. This results in a much leaner syntax than the typical ASP.NET Web Forms alligator (<% %>) tags. Razor uses the @ sign plus standard C# (or Visual Basic) block syntax to delineate code snippets and expressions. Here’s a very simple example of what Razor markup looks like along with some comment annotations: <!DOCTYPE html> <html>     <head>         <title></title>     </head>     <body>     <h1>Razor Test</h1>          <!-- simple expressions -->     @DateTime.Now     <hr />     <!-- method expressions -->     @DateTime.Now.ToString("T")          <!-- code blocks -->     @{         List<string> names = new List<string>();         names.Add("Rick");         names.Add("Markus");         names.Add("Claudio");         names.Add("Kevin");     }          <!-- structured block statements -->     <ul>     @foreach(string name in names){             <li>@name</li>     }     </ul>           <!-- Conditional code -->        @if(true) {                        <!-- Literal Text embedding in code -->        <text>         true        </text>;    }    else    {        <!-- Literal Text embedding in code -->       <text>       false       </text>;    }    </body> </html> Like the Web Forms view engine, Razor parses pages into code, and then executes that run-time compiled code. Effectively a “page” becomes a code file with markup becoming literal text written into the Response stream, code snippets becoming raw code, and expressions being written out with Response.Write(). The code generated from Razor doesn’t look much different from similar Web Forms code that only uses script tags; so although the syntax may look different, the operational model is fairly similar to the Web Forms engine minus the overhead of the large Page object model. However, there are differences: -Razor pages are based on a new base class, Microsoft.WebPages.WebPage, which is hosted in the Microsoft.WebPages assembly that houses all the Razor engine parsing and processing logic. Browsing through the assembly (in the generated ASP.NET Temporary Files folder or GAC) will give you a good idea of the functionality that Razor provides. If you look closely, a lot of the feature set matches ASP.NET MVC’s view implementation as well as many of the helper classes found in MVC. It’s not hard to guess the motivation for this sort of view engine: For beginning developers the simple markup syntax is easier to work with, although you obviously still need to have some understanding of the .NET Framework in order to create dynamic content. The syntax is easier to read and grok and much shorter to type than ASP.NET alligator tags (<% %>) and also easier to understand aesthetically what’s happening in the markup code. Razor also is a better fit for Microsoft’s vision of ASP.NET MVC: It’s a new view engine without the baggage of Web Forms attached to it. The engine is more lightweight since it doesn’t carry all the features and object model of Web Forms with it and it can be instantiated directly outside of the HTTP environment, which has been rather tricky to do for the Web Forms view engine. Having a standalone script parser is a huge win for other applications as well – it makes it much easier to create script or meta driven output generators for many types of applications from code/screen generators, to simple form letters to data merging applications with user customizability. For me personally this is very useful side effect and who knows maybe Microsoft will actually standardize they’re scripting engines (die T4 die!) on this engine. Razor also better fits the “view-based” approach where the view is supposed to be mostly a visual representation that doesn’t hold much, if any, code. While you can still use code, the code you do write has to be self-contained. Overall I wouldn’t be surprised if Razor will become the new standard view engine for MVC in the future – and in fact there have been announcements recently that Razor will become the default script engine in ASP.NET MVC 3.0. Razor can also be used in existing Web Forms and MVC applications, although that’s not working currently unless you manually configure the script mappings and add the appropriate assemblies. It’s possible to do it, but it’s probably better to wait until Microsoft releases official support for Razor scripts in Visual Studio. Once that happens, you can simply drop .cshtml and .vbhtml pages into an existing ASP.NET project and they will work side by side with classic ASP.NET pages. WebMatrix Development Environment To tie all of these three technologies together, Microsoft is shipping WebMatrix with an integrated development environment. An integrated gallery manager makes it easy to download and load existing projects, and then extend them with custom functionality. It seems to be a prominent goal to provide community-oriented content that can act as a starting point, be it via a custom templates or a complete standard application. The IDE includes a project manager that works with a single project and provides an integrated IDE/editor for editing the .cshtml and .vbhtml pages. A run button allows you to quickly run pages in the project manager in a variety of browsers. There’s no debugging support for code at this time. Note that Razor pages don’t require explicit compilation, so making a change, saving, and then refreshing your page in the browser is all that’s needed to see changes while testing an application locally. It’s essentially using the auto-compiling Web Project that was introduced with .NET 2.0. All code is compiled during run time into dynamically created assemblies in the ASP.NET temp folder. WebMatrix also has PHP Editing support with syntax highlighting. You can load various PHP-based applications from the WebMatrix Web Gallery directly into the IDE. Most of the Web Gallery applications are ready to install and run without further configuration, with Wizards taking you through installation of tools, dependencies, and configuration of the database as needed. WebMatrix leverages the Web Platform installer to pull the pieces down from websites in a tight integration of tools that worked nicely for the four or five applications I tried this out on. Click a couple of check boxes and fill in a few simple configuration options and you end up with a running application that’s ready to be customized. Nice! You can easily deploy completed applications via WebDeploy (to an IIS server) or FTP directly from within the development environment. The deploy tool also can handle automatically uploading and installing the database and all related assemblies required, making deployment a simple one-click install step. Simplified Database Access The IDE contains a database editor that can edit SQL Compact and SQL Server databases. There is also a Database helper class that facilitates database access by providing easy-to-use, high-level query execution and iteration methods: @{       var db = Database.OpenFile("FirstApp.sdf");     string sql = "select * from customers where Id > @0"; } <ul> @foreach(var row in db.Query(sql,1)){         <li>@row.FirstName @row.LastName</li> } </ul> The query function takes a SQL statement plus any number of positional (@0,@1 etc.) SQL parameters by simple values. The result is returned as a collection of rows which in turn have a row object with dynamic properties for each of the columns giving easy (though untyped) access to each of the fields. Likewise Execute and ExecuteNonQuery allow execution of more complex queries using similar parameter passing schemes. Note these queries use string-based queries rather than LINQ or Entity Framework’s strongly typed LINQ queries. While this may seem like a step back, it’s also in line with the expectations of non .NET script developers who are quite used to writing and using SQL strings in code rather than using OR/M frameworks. The only question is why was something not included from the beginning in .NET and Microsoft made developers build custom implementations of these basic building blocks. The implementation looks a lot like a DataTable-style data access mechanism, but to be fair, this is a common approach in scripting languages. This type of syntax that uses simple, static, data object methods to perform simple data tasks with one line of code are common in scripting languages and are a good match for folks working in PHP/Python, etc. Seems like Microsoft has taken great advantage of .NET 4.0’s dynamic typing to provide this sort of interface for row iteration where each row has properties for each field. FWIW, all the examples demonstrate using local SQL Compact files - I was unable to get a SQL Server connection string to work with the Database class (the connection string wasn’t accepted). However, since the code in the page is still plain old .NET, you can easily use standard ADO.NET code or even LINQ or Entity Framework models that are created outside of WebMatrix in separate assemblies as required. The good the bad the obnoxious - It’s still .NET The beauty (or curse depending on how you look at it :)) of Razor and the compilation model is that, behind it all, it’s still .NET. Although the syntax may look foreign, it’s still all .NET behind the scenes. You can easily access existing tools, helpers, and utilities simply by adding them to the project as references or to the bin folder. Razor automatically recognizes any assembly reference from assemblies in the bin folder. In the default configuration, Microsoft provides a host of helper functions in a Microsoft.WebPages assembly (check it out in the ASP.NET temp folder for your application), which includes a host of HTML Helpers. If you’ve used ASP.NET MVC before, a lot of the helpers should look familiar. Documentation at the moment is sketchy-there’s a very rough API reference you can check out here: http://www.asp.net/webmatrix/tutorials/asp-net-web-pages-api-reference Who needs WebMatrix? Uhm… good Question Clearly Microsoft is trying hard to create an environment with WebMatrix that is easy to use for newbie developers. The goal seems to be simplicity in providing a minimal development environment and an easy-to-use script engine/language that makes it easy to get started with. There’s also some focus on community features that can be used as starting points, such as Web Gallery applications and templates. The community features in particular are very nice and something that would be nice to eventually see in Visual Studio as well. The question is whether this is too little too late. Developers who have been clamoring for a simpler development environment on the .NET stack have mostly left for other simpler platforms like PHP or Python which are catering to the down and dirty developer. Microsoft will be hard pressed to win those folks-and other hardcore PHP developers-back. Regardless of how much you dress up a script engine fronted by the .NET Framework, it’s still the .NET Framework and all the complexity that drives it. While .NET is a fine solution in its breadth and features once you get a basic handle on the core features, the bar of entry to being productive with the .NET Framework is still pretty high. The MVC style helpers Microsoft provides are a good step in the right direction, but I suspect it’s not enough to shield new developers from having to delve much deeper into the Framework to get even basic applications built. Razor and its helpers is trying to make .NET more accessible but the reality is that in order to do useful stuff that goes beyond the handful of simple helpers you still are going to have to write some C# or VB or other .NET code. If the target is a hobby/amateur/non-programmer the learning curve isn’t made any easier by WebMatrix it’s just been shifted a tad bit further along in your development endeavor when you run out of canned components that are supplied either by Microsoft or the community. The database helpers are interesting and actually I’ve heard a lot of discussion from various developers who’ve been resisting .NET for a really long time perking up at the prospect of easier data access in .NET than the ridiculous amount of code it takes to do even simple data access with raw ADO.NET. It seems sad that such a simple concept and implementation should trigger this sort of response (especially since it’s practically trivial to create helpers like these or pick them up from countless libraries available), but there it is. It also shows that there are plenty of developers out there who are more interested in ‘getting stuff done’ easily than necessarily following the latest and greatest practices which are overkill for many development scenarios. Sometimes it seems that all of .NET is focused on the big life changing issues of development, rather than the bread and butter scenarios that many developers are interested in to get their work accomplished. And that in the end may be WebMatrix’s main raison d'être: To bring some focus back at Microsoft that simpler and more high level solutions are actually needed to appeal to the non-high end developers as well as providing the necessary tools for the high end developers who want to follow the latest and greatest trends. The current version of WebMatrix hits many sweet spots, but it also feels like it has a long way to go before it really can be a tool that a beginning developer or an accomplished developer can feel comfortable with. Although there are some really good ideas in the environment (like the gallery for downloading apps and components) which would be a great addition for Visual Studio as well, the rest of the development environment just feels like crippleware with required functionality missing especially debugging and Intellisense, but also general editor support. It’s not clear whether these are because the product is still in an early alpha release or whether it’s simply designed that way to be a really limited development environment. While simple can be good, nobody wants to feel left out when it comes to necessary tool support and WebMatrix just has that left out feeling to it. If anything WebMatrix’s technology pieces (which are really independent of the WebMatrix product) are what are interesting to developers in general. The compact IIS implementation is a nice improvement for development scenarios and SQL Compact 4.0 seems to address a lot of concerns that people have had and have complained about for some time with previous SQL Compact implementations. By far the most interesting and useful technology though seems to be the Razor view engine for its light weight implementation and it’s decoupling from the ASP.NET/HTTP pipeline to provide a standalone scripting/view engine that is pluggable. The first winner of this is going to be ASP.NET MVC which can now have a cleaner view model that isn’t inconsistent due to the baggage of non-implemented WebForms features that don’t work in MVC. But I expect that Razor will end up in many other applications as a scripting and code generation engine eventually. Visual Studio integration for Razor is currently missing, but is promised for a later release. The ASP.NET MVC team has already mentioned that Razor will eventually become the default MVC view engine, which will guarantee continued growth and development of this tool along those lines. And the Razor engine and support tools actually inherit many of the features that MVC pioneered, so there’s some synergy flowing both ways between Razor and MVC. As an existing ASP.NET developer who’s already familiar with Visual Studio and ASP.NET development, the WebMatrix IDE doesn’t give you anything that you want. The tools provided are minimal and provide nothing that you can’t get in Visual Studio today, except the minimal Razor syntax highlighting, so there’s little need to take a step back. With Visual Studio integration coming later there’s little reason to look at WebMatrix for tooling. It’s good to see that Microsoft is giving some thought about the ease of use of .NET as a platform For so many years, we’ve been piling on more and more new features without trying to take a step back and see how complicated the development/configuration/deployment process has become. Sometimes it’s good to take a step - or several steps - back and take another look and realize just how far we’ve come. WebMatrix is one of those reminders and one that likely will result in some positive changes on the platform as a whole. © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET   IIS7  

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  • How to batch rename files using bash

    - by Alex Popov
    I know there are lots of such questions, but I couldn't find one (or a combination of several), which describes the things I want to do. I think I need to use regular expressions, but I am not very good with that. I use zsh. I have a folder with files, which I want to rename: I want the files challenge1.rb, challenge2.rb, challenge3.rb, etc. to be renamed to c1.rb, c2.rb etc. Similarly task1.rb and similar must be renamed to t1.rb etc. sample_spec_c1.rb, sample_spec_c2.rb etc. must be renamed to c1_spec.rb, c2_spec.rb etc. So I guess I need some combination of regular expressions and iteration, but I don't know how to write the bash script.

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  • Weblogic JMS System Error

    - by Jeune
    We're getting a JMS error which we don't have a lot to go with: org.springframework.jms.UncategorizedJmsException: Uncategorized exception occured during JMS processing; nested exception is weblogic.jms.common.JMSException:[JMSClientExceptions:055039] A system error has occurred. The error is java.lang.NullPointerException; nested exception is java.lang.NullPointerException at com.pg.ecom.jms.service.ProducerServices.SendMessageSync(ProducerServices.java:131) at com.pg.ecom.jms.service.ProducerServices.SendMessageSync(ProducerServices.java:115) at com.pg.ecom.jms.producer.FormsCRRProducer.sendMessage(FormsCRRProducer.java:56) at com.pg.ecom.cpgt.processruleagent.managerbean.forms.GenerateFormsManagerBean.useNewGetTemplateData(GenerateFormsManagerBean.java:522) at com.pg.ecom.cpgt.processruleagent.managerbean.forms.GenerateFormsManagerBean.doService(GenerateFormsManagerBean.java:114) at com.pg.ecom.fw.processcontainer.AbstractManagerBean.doServiceWrapper(AbstractManagerBean.java:175) at com.pg.ecom.fw.processcontainer.AbstractManagerBean.doServiceRequest(AbstractManagerBean.java:151) at com.pg.ecom.fw.processcontainer.AbstractServlet.doManagerBeanServiceAndPresentation(AbstractServlet.java:1911) at com.pg.ecom.cpgt.processunit.servlet.CportalParamServlet.doService(CportalParamServlet.java:107) at com.pg.ecom.fw.processcontainer.AbstractServlet.service(AbstractServlet.java:983) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227) at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125) at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283) at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26) at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42) at com.pg.ecom.cpgt.processunit.filter.UploadMultipartFilter.doFilter(UploadMultipartFilter.java:28) at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42) at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3229) at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321) at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121) at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2002) at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1908) at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1362) at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209) at weblogic.work.ExecuteThread.run(ExecuteThread.java:181) The only lead I have is line 127 in the code which is indicated by this error: Caused by: weblogic.jms.common.JMSException: [JMSClientExceptions:055039]A system error has occurred. The error is java.lang.Nul lPointerException at weblogic.jms.client.JMSSession.handleException(JMSSession.java:2853) at weblogic.jms.client.JMSConsumer.receive(JMSConsumer.java:629) at weblogic.jms.client.JMSConsumer.receive(JMSConsumer.java:488) at weblogic.jms.client.WLConsumerImpl.receive(WLConsumerImpl.java:155) at org.springframework.jms.core.JmsTemplate.doReceive(JmsTemplate.java:734) at org.springframework.jms.core.JmsTemplate.doReceive(JmsTemplate.java:706) at org.springframework.jms.core.JmsTemplate$9.doInJms(JmsTemplate.java:681) at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:447) at org.springframework.jms.core.JmsTemplate.receiveSelected(JmsTemplate.java:679) at org.springframework.jms.core.JmsTemplate.receiveSelectedAndConvert(JmsTemplate.java:784) at com.pg.ecom.jms.service.ProducerServices.SendMessageSync(ProducerServices.java:127) ... 25 more This is line 127: try { Thread.yield(); //line 127 below status=(StatusMessageBean)getJmsTemplate.receiveSelectedAndConvert(statusDestination, "JMSCorrelationID='"+ producerMsg.getProcessID() +"'"); Thread.yield(); } catch (Exception e) { Thread.yield(); loggingInterface.doErrorLogging(e.fillInStackTrace()); } According to the BEA documentation, we should contact BEA about error 055039 but I would like to try asking here first before bringing this to them? Some more errors: Caused by: java.lang.NullPointerException at weblogic.jms.common.JMSVariableBinder$JMSCorrelationIDVariable.get(JMSVariableBinder.java:127) at weblogic.utils.expressions.Expression.evaluateExpr(Expression.java:271) at weblogic.utils.expressions.Expression.evaluateExpr(Expression.java:298) at weblogic.utils.expressions.Expression.evaluateBoolean(Expression.java:209) at weblogic.utils.expressions.Expression.evaluate(Expression.java:167) at weblogic.jms.common.JMSSQLFilter$Exp.evaluate(JMSSQLFilter.java:304) at weblogic.messaging.common.SQLFilter.match(SQLFilter.java:158) at weblogic.messaging.kernel.internal.MessageList.findNextVisible(MessageList.java:274) at weblogic.messaging.kernel.internal.QueueImpl.nextFromIteratorOrGroup(QueueImpl.java:441) at weblogic.messaging.kernel.internal.QueueImpl.nextMatchFromIteratorOrGroup(QueueImpl.java:350) at weblogic.messaging.kernel.internal.QueueImpl.get(QueueImpl.java:233) at weblogic.messaging.kernel.internal.QueueImpl.addReader(QueueImpl.java:1069) at weblogic.messaging.kernel.internal.ReceiveRequestImpl.start(ReceiveRequestImpl.java:178) at weblogic.messaging.kernel.internal.ReceiveRequestImpl.<init>(ReceiveRequestImpl.java:86) at weblogic.messaging.kernel.internal.QueueImpl.receive(QueueImpl.java:820) at weblogic.jms.backend.BEConsumerImpl.blockingReceiveStart(BEConsumerImpl.java:1172) at weblogic.jms.backend.BEConsumerImpl.receive(BEConsumerImpl.java:1383) at weblogic.jms.backend.BEConsumerImpl.invoke(BEConsumerImpl.java:1088) at weblogic.messaging.dispatcher.Request.wrappedFiniteStateMachine(Request.java:759) at weblogic.messaging.dispatcher.DispatcherImpl.dispatchAsyncInternal(DispatcherImpl.java:129) at weblogic.messaging.dispatcher.DispatcherImpl.dispatchAsync(DispatcherImpl.java:112) at weblogic.messaging.dispatcher.Request.dispatchAsync(Request.java:1046) at weblogic.jms.dispatcher.Request.dispatchAsync(Request.java:72) at weblogic.jms.frontend.FEConsumer.receive(FEConsumer.java:557) at weblogic.jms.frontend.FEConsumer.invoke(FEConsumer.java:806) at weblogic.messaging.dispatcher.Request.wrappedFiniteStateMachine(Request.java:759) at weblogic.messaging.dispatcher.DispatcherServerRef.invoke(DispatcherServerRef.java:276) at weblogic.messaging.dispatcher.DispatcherServerRef.handleRequest(DispatcherServerRef.java:141) at weblogic.messaging.dispatcher.DispatcherServerRef.access$000(DispatcherServerRef.java:36) at weblogic.messaging.dispatcher.DispatcherServerRef$2.run(DispatcherServerRef.java:112) ... 2 more Any ideas?

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  • How to use objects as modules/functors in Scala?

    - by Jeff
    Hi. I want to use object instances as modules/functors, more or less as shown below: abstract class Lattice[E] extends Set[E] { val minimum: E val maximum: E def meet(x: E, y: E): E def join(x: E, y: E): E def neg(x: E): E } class Calculus[E](val lat: Lattice[E]) { abstract class Expr case class Var(name: String) extends Expr {...} case class Val(value: E) extends Expr {...} case class Neg(e1: Expr) extends Expr {...} case class Cnj(e1: Expr, e2: Expr) extends Expr {...} case class Dsj(e1: Expr, e2: Expr) extends Expr {...} } So that I can create a different calculus instance for each lattice (the operations I will perform need the information of which are the maximum and minimum values of the lattice). I want to be able to mix expressions of the same calculus but not be allowed to mix expressions of different ones. So far, so good. I can create my calculus instances, but problem is that I can not write functions in other classes that manipulate them. For example, I am trying to create a parser to read expressions from a file and return them; I also was trying to write an random expression generator to use in my tests with ScalaCheck. Turns out that every time a function generates an Expr object I can't use it outside the function. Even if I create the Calculus instance and pass it as an argument to the function that will in turn generate the Expr objects, the return of the function is not recognized as being of the same type of the objects created outside the function. Maybe my english is not clear enough, let me try a toy example of what I would like to do (not the real ScalaCheck generator, but close enough). def genRndExpr[E](c: Calculus[E], level: Int): Calculus[E]#Expr = { if (level > MAX_LEVEL) { val select = util.Random.nextInt(2) select match { case 0 => genRndVar(c) case 1 => genRndVal(c) } } else { val select = util.Random.nextInt(3) select match { case 0 => new c.Neg(genRndExpr(c, level+1)) case 1 => new c.Dsj(genRndExpr(c, level+1), genRndExpr(c, level+1)) case 2 => new c.Cnj(genRndExpr(c, level+1), genRndExpr(c, level+1)) } } } Now, if I try to compile the above code I get lots of error: type mismatch; found : plg.mvfml.Calculus[E]#Expr required: c.Expr case 0 = new c.Neg(genRndExpr(c, level+1)) And the same happens if I try to do something like: val boolCalc = new Calculus(Bool) val e1: boolCalc.Expr = genRndExpr(boolCalc) Please note that the generator itself is not of concern, but I will need to do similar things (i.e. create and manipulate calculus instance expressions) a lot on the rest of the system. Am I doing something wrong? Is it possible to do what I want to do? Help on this matter is highly needed and appreciated. Thanks a lot in advance. After receiving an answer from Apocalisp and trying it. Thanks a lot for the answer, but there are still some issues. The proposed solution was to change the signature of the function to: def genRndExpr[E, C <: Calculus[E]](c: C, level: Int): C#Expr I changed the signature for all the functions involved: getRndExpr, getRndVal and getRndVar. And I got the same error message everywhere I call these functions and got the following error message: error: inferred type arguments [Nothing,C] do not conform to method genRndVar's type parameter bounds [E,C genRndVar(c) Since the compiler seemed to be unable to figure out the right types I changed all function call to be like below: case 0 => new c.Neg(genRndExpr[E,C](c, level+1)) After this, on the first 2 function calls (genRndVal and genRndVar) there were no compiling error, but on the following 3 calls (recursive calls to genRndExpr), where the return of the function is used to build a new Expr object I got the following error: error: type mismatch; found : C#Expr required: c.Expr case 0 = new c.Neg(genRndExpr[E,C](c, level+1)) So, again, I'm stuck. Any help will be appreciated.

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  • Why are there 3 conflicting OpenCV camera calibration formulas?

    - by John
    I'm having a problem with OpenCV's various parameterization of coordinates used for camera calibration purposes. The problem is that three different sources of information on image distortion formulae apparently give three non-equivalent description of the parameters and equations involved: (1) In their book "Learning OpenCV…" Bradski and Kaehler write regarding lens distortion (page 376): xcorrected = x * ( 1 + k1 * r^2 + k2 * r^4 + k3 * r^6 ) + [ 2 * p1 * x * y + p2 * ( r^2 + 2 * x^2 ) ], ycorrected = y * ( 1 + k1 * r^2 + k2 * r^4 + k3 * r^6 ) + [ p1 * ( r^2 + 2 * y^2 ) + 2 * p2 * x * y ], where r = sqrt( x^2 + y^2 ). Assumably, (x, y) are the coordinates of pixels in the uncorrected captured image corresponding to world-point objects with coordinates (X, Y, Z), camera-frame referenced, for which xcorrected = fx * ( X / Z ) + cx and ycorrected = fy * ( Y / Z ) + cy, where fx, fy, cx, and cy, are the camera's intrinsic parameters. So, having (x, y) from a captured image, we can obtain the desired coordinates ( xcorrected, ycorrected ) to produced an undistorted image of the captured world scene by applying the above first two correction expressions. However... (2) The complication arises as we look at OpenCV 2.0 C Reference entry under the Camera Calibration and 3D Reconstruction section. For ease of comparison we start with all world-point (X, Y, Z) coordinates being expressed with respect to the camera's reference frame, just as in #1. Consequently, the transformation matrix [ R | t ] is of no concern. In the C reference, it is expressed that: x' = X / Z, y' = Y / Z, x'' = x' * ( 1 + k1 * r'^2 + k2 * r'^4 + k3 * r'^6 ) + [ 2 * p1 * x' * y' + p2 * ( r'^2 + 2 * x'^2 ) ], y'' = y' * ( 1 + k1 * r'^2 + k2 * r'^4 + k3 * r'^6 ) + [ p1 * ( r'^2 + 2 * y'^2 ) + 2 * p2 * x' * y' ], where r' = sqrt( x'^2 + y'^2 ), and finally that u = fx * x'' + cx, v = fy * y'' + cy. As one can see these expressions are not equivalent to those presented in #1, with the result that the two sets of corrected coordinates ( xcorrected, ycorrected ) and ( u, v ) are not the same. Why the contradiction? It seems to me the first set makes more sense as I can attach physical meaning to each and every x and y in there, while I find no physical meaning in x' = X / Z and y' = Y / Z when the camera focal length is not exactly 1. Furthermore, one cannot compute x' and y' for we don't know (X, Y, Z). (3) Unfortunately, things get even murkier when we refer to the writings in Intel's Open Source Computer Vision Library Reference Manual's section Lens Distortion (page 6-4), which states in part: "Let ( u, v ) be true pixel image coordinates, that is, coordinates with ideal projection, and ( u ~, v ~ ) be corresponding real observed (distorted) image coordinates. Similarly, ( x, y ) are ideal (distortion-free) and ( x ~, y ~ ) are real (distorted) image physical coordinates. Taking into account two expansion terms gives the following: x ~ = x * ( 1 + k1 * r^2 + k2 * r^4 ) + [ 2 p1 * x * y + p2 * ( r^2 + 2 * x^2 ) ] y ~ = y * ( 1 + k1 * r^2 + k2 * r^4 ] + [ 2 p2 * x * y + p2 * ( r^2 + 2 * y^2 ) ], where r = sqrt( x^2 + y^2 ). ... "Because u ~ = cx + fx * u and v ~ = cy + fy * v , … the resultant system can be rewritten as follows: u ~ = u + ( u – cx ) * [ k1 * r^2 + k2 * r^4 + 2 * p1 * y + p2 * ( r^2 / x + 2 * x ) ] v ~ = v + ( v – cy ) * [ k1 * r^2 + k2 * r^4 + 2 * p2 * x + p1 * ( r^2 / y + 2 * y ) ] The latter relations are used to undistort images from the camera." Well, it would appear that the expressions involving x ~ and y ~ coincided with the two expressions given at the top of this writing involving xcorrected and ycorrected. However, x ~ and y ~ do not refer to corrected coordinates, according to the given description. I don't understand the distinction between the meaning of the coordinates ( x ~, y ~ ) and ( u ~, v ~ ), or for that matter, between the pairs ( x, y ) and ( u, v ). From their descriptions it appears their only distinction is that ( x ~, y ~ ) and ( x, y ) refer to 'physical' coordinates while ( u ~, v ~ ) and ( u, v ) do not. What is this distinction all about? Aren't they all physical coordinates? I'm lost! Thanks for any input!

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  • Employee Info Starter Kit - Visual Studio 2010 and .NET 4.0 Version (4.0.0) Available

    - by joycsharp
    Employee Info Starter Kit is a ASP.NET based web application, which includes very simple user requirements, where we can create, read, update and delete (crud) the employee info of a company. Based on just a database table, it explores and solves all major problems in web development architectural space.  This open source starter kit extensively uses major features available in latest Visual Studio, ASP.NET and Sql Server to make robust, scalable, secured and maintanable web applications quickly and easily. Since it's first release, this starter kit achieved a huge popularity in web developer community and includes 1,40,000+ download from project web site. Visual Studio 2010 and .NET 4.0 came up with lots of exciting features to make software developers life easier.  A new version (v4.0.0) of Employee Info Starter Kit is now available in both MSDN Code Gallery and CodePlex. Chckout the latest version of this starter kit to enjoy cool features available in Visual Studio 2010 and .NET 4.0. [ Release Notes ] Architectural Overview Simple 2 layer architecture (user interface and data access layer) with 1 optional cache layer ASP.NET Web Form based user interface Custom Entity Data Container implemented (with primitive C# types for data fields) Active Record Design Pattern based Data Access Layer, implemented in C# and Entity Framework 4.0 Sql Server Stored Procedure to perform actual CRUD operation Standard infrastructure (architecture, helper utility) for automated integration (bottom up manner) and unit testing Technology UtilizedProgramming Languages/Scripts Browser side: JavaScript Web server side: C# 4.0 Database server side: T-SQL .NET Framework Components .NET 4.0 Entity Framework .NET 4.0 Optional/Named Parameters .NET 4.0 Tuple .NET 3.0+ Extension Method .NET 3.0+ Lambda Expressions .NET 3.0+ Aanonymous Type .NET 3.0+ Query Expressions .NET 3.0+ Automatically Implemented Properties .NET 3.0+ LINQ .NET 2.0 + Partial Classes .NET 2.0 + Generic Type .NET 2.0 + Nullable Type   ASP.NET 3.5+ List View (TBD) ASP.NET 3.5+ Data Pager (TBD) ASP.NET 2.0+ Grid View ASP.NET 2.0+ Form View ASP.NET 2.0+ Skin ASP.NET 2.0+ Theme ASP.NET 2.0+ Master Page ASP.NET 2.0+ Object Data Source ASP.NET 1.0+ Role Based Security Visual Studio Features Visual Studio 2010 CodedUI Test Visual Studio 2010 Layer Diagram Visual Studio 2010 Sequence Diagram Visual Studio 2010 Directed Graph Visual Studio 2005+ Database Unit Test Visual Studio 2005+ Unit Test Visual Studio 2005+ Web Test Visual Studio 2005+ Load Test Sql Server Features Sql Server 2005 Stored Procedure Sql Server 2005 Xml type Sql Server 2005 Paging support

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  • Employee Info Starter Kit - Visual Studio 2010 and .NET 4.0 Version (4.0.0) Available

    - by Mohammad Ashraful Alam
    Employee Info Starter Kit is a ASP.NET based web application, which includes very simple user requirements, where we can create, read, update and delete (crud) the employee info of a company. Based on just a database table, it explores and solves most of the major problems in web development architectural space.  This open source starter kit extensively uses major features available in latest Visual Studio, ASP.NET and Sql Server to make robust, scalable, secured and maintanable web applications quickly and easily. Since it's first release, this starter kit achieved a huge popularity in web developer community and includes 1,40,000+ download from project web site. Visual Studio 2010 and .NET 4.0 came up with lots of exciting features to make software developers life easier.  A new version (v4.0.0) of Employee Info Starter Kit is now available in both MSDN Code Gallery and CodePlex. Chckout the latest version of this starter kit to enjoy cool features available in Visual Studio 2010 and .NET 4.0. [ Release Notes ] Architectural Overview Simple 2 layer architecture (user interface and data access layer) with 1 optional cache layer ASP.NET Web Form based user interface Custom Entity Data Container implemented (with primitive C# types for data fields) Active Record Design Pattern based Data Access Layer, implemented in C# and Entity Framework 4.0 Sql Server Stored Procedure to perform actual CRUD operation Standard infrastructure (architecture, helper utility) for automated integration (bottom up manner) and unit testing Technology UtilizedProgramming Languages/Scripts Browser side: JavaScript Web server side: C# 4.0 Database server side: T-SQL .NET Framework Components .NET 4.0 Entity Framework .NET 4.0 Optional/Named Parameters .NET 4.0 Tuple .NET 3.0+ Extension Method .NET 3.0+ Lambda Expressions .NET 3.0+ Aanonymous Type .NET 3.0+ Query Expressions .NET 3.0+ Automatically Implemented Properties .NET 3.0+ LINQ .NET 2.0 + Partial Classes .NET 2.0 + Generic Type .NET 2.0 + Nullable Type   ASP.NET 3.5+ List View (TBD) ASP.NET 3.5+ Data Pager (TBD) ASP.NET 2.0+ Grid View ASP.NET 2.0+ Form View ASP.NET 2.0+ Skin ASP.NET 2.0+ Theme ASP.NET 2.0+ Master Page ASP.NET 2.0+ Object Data Source ASP.NET 1.0+ Role Based Security Visual Studio Features Visual Studio 2010 CodedUI Test Visual Studio 2010 Layer Diagram Visual Studio 2010 Sequence Diagram Visual Studio 2010 Directed Graph Visual Studio 2005+ Database Unit Test Visual Studio 2005+ Unit Test Visual Studio 2005+ Web Test Visual Studio 2005+ Load Test Sql Server Features Sql Server 2005 Stored Procedure Sql Server 2005 Xml type Sql Server 2005 Paging support

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  • Parsing HTML Documents with the Html Agility Pack

    Screen scraping is the process of programmatically accessing and processing information from an external website. For example, a price comparison website might screen scrape a variety of online retailers to build a database of products and what various retailers are selling them for. Typically, screen scraping is performed by mimicking the behavior of a browser - namely, by making an HTTP request from code and then parsing and analyzing the returned HTML. The .NET Framework offers a variety of classes for accessing data from a remote website, namely the WebClient class and the HttpWebRequest class. These classes are useful for making an HTTP request to a remote website and pulling down the markup from a particular URL, but they offer no assistance in parsing the returned HTML. Instead, developers commonly rely on string parsing methods like String.IndexOf, String.Substring, and the like, or through the use of regular expressions. Another option for parsing HTML documents is to use the Html Agility Pack, a free, open-source library designed to simplify reading from and writing to HTML documents. The Html Agility Pack constructs a Document Object Model (DOM) view of the HTML document being parsed. With a few lines of code, developers can walk through the DOM, moving from a node to its children, or vice versa. Also, the Html Agility Pack can return specific nodes in the DOM through the use of XPath expressions. (The Html Agility Pack also includes a class for downloading an HTML document from a remote website; this means you can both download and parse an external web page using the Html Agility Pack.) This article shows how to get started using the Html Agility Pack and includes a number of real-world examples that illustrate this library's utility. A complete, working demo is available for download at the end of this article. Read on to learn more! Read More >

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  • Uget tray icon not showing

    - by ArK
    Since I upgraded to Saucy, Uget is not showing in the system tray, although the Always show tray icon option in Uget settings is checked. P.S. this happens only with Uget, all the other Softwares have working tray icons (vlc,qbittorrent..) Here is the snapshot which shows the settings of Uget: sudo dpkg -l | grep -e "^rc" -e "^iU": rc account-plugin-generic-oauth 0.10bzr13.03.26-0ubuntu1.1 i386 GNOME Control Center account plugin for single signon - generic OAuth rc appmenu-gtk:i386 12.10.3daily13.04.03-0ubuntu1 i386 Export GTK menus over DBus rc appmenu-gtk3:i386 12.10.3daily13.04.03-0ubuntu1 i386 Export GTK menus over DBus rc arora 0.11.0-0ubuntu1 i386 simple cross platform web browser rc buc 0.5.2-20 i386 BUC rc clementine 1.1.1+dfsg-2ubuntu1 i386 modern music player and library organizer rc epiphany-browser 3.6.1-2ubuntu1 i386 Intuitive GNOME web browser rc epiphany-browser-data 3.6.1-2ubuntu3 all Data files for the GNOME web browser rc fancontrol 1:3.3.3-1ubuntu1 all utilities to read temperature/voltage/fan sensors rc flaremonitor 1.0-5 i386 It is an advanced browser integration helper module of FlareGet rc google-chrome-stable 28.0.1500.95-r213514 i386 The web browser from Google rc hal 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer rc hotot-gtk 1:0.9.8.5+git20120630.884797d-1 all lightweight microblogging client - GTK+ wrapper rc jockey-common 0.9.7-0ubuntu13 all user interface and desktop integration for driver management rc libanalitza4abi1 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions rc libanalitza5 4:4.11.2-0ubuntu1 i386 library to work with mathematical expressions rc libanalitzagui4abi2 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions - GUI routines rc libanalitzaplot4 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions - plot routines rc libavcodec53:i386 6:0.8.6-1ubuntu2 i386 Libav codec library rc libavutil51:i386 6:0.8.6-1ubuntu2 i386 Libav utility library rc libbamf3-1:i386 0.4.0daily13.06.19~13.04-0ubuntu1 i386 Window matching library - shared library rc libboost-iostreams1.49.0 1.49.0-4 i386 Boost.Iostreams Library rc libboost-program-options1.49.0 1.49.0-4 i386 program options library for C++ rc libboost-python1.49.0 1.49.0-4 i386 Boost.Python Library rc libboost-thread1.49.0 1.49.0-4 i386 portable C++ multi-threading rc libbrlapi0.5:i386 4.4-8ubuntu4 i386 braille display access via BRLTTY - shared library rc libcamel-1.2-40 3.6.4-0ubuntu1.1 i386 Evolution MIME message handling library rc libcolumbus0-0 0.4.0daily13.04.16~13.04-0ubuntu1 i386 error tolerant matching engine - shared library rc libdns95 1:9.9.2.dfsg.P1-2ubuntu2.1 i386 DNS Shared Library used by BIND rc libdvbpsi7 0.2.2-1 i386 library for MPEG TS and DVB PSI tables decoding and generating rc libebackend-1.2-5 3.6.4-0ubuntu1.1 i386 Utility library for evolution data servers rc libechonest2.0:i386 2.0.2-0ubuntu1 i386 Qt library for communicating with The Echo Nest platform rc libechonest2.1:i386 2.1.0-2 i386 Qt library for communicating with The Echo Nest platform rc libedata-book-1.2-15 3.6.4-0ubuntu1.1 i386 Backend library for evolution address books rc libedata-cal-1.2-18 3.6.4-0ubuntu1.1 i386 Backend library for evolution calendars rc libftgl2 2.1.3~rc5-4ubuntu1 i386 library to render text in OpenGL using FreeType rc libgc1c3:i386 1:7.2d-0ubuntu5 i386 conservative garbage collector for C and C++ rc libgnome-desktop-3-4 3.6.3-0ubuntu1 i386 Utility library for loading .desktop files - runtime files rc libgtksourceview-3.0-0:i386 3.6.3-0ubuntu1 i386 shared libraries for the GTK+ syntax highlighting widget rc libgweather-3-1 3.6.2-0ubuntu1 i386 GWeather shared library rc libhal-storage1 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer - shared library for storage devices rc libhal1 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer - shared library rc libharfbuzz0:i386 0.9.13-1 i386 OpenType text shaping engine rc libhd16 16.0-2.2 i386 Hardware identification system library rc libibus-1.0-0:i386 1.4.2-0ubuntu2 i386 Intelligent Input Bus - shared library rc libical0 0.48-2 i386 iCalendar library implementation in C (runtime) rc libimobiledevice3 1.1.4-1ubuntu6.2 i386 Library for communicating with the iPhone and iPod Touch rc libisc92 1:9.9.2.dfsg.P1-2ubuntu2.1 i386 ISC Shared Library used by BIND rc libkdegamesprivate1 4:4.10.2-0ubuntu1 i386 private shared library for KDE games rc libkeybinder0 0.3.0-1ubuntu1 i386 registers global key bindings for applications rc libkgapi0:i386 0.4.4-0ubuntu1 i386 Google API library for KDE rc liblastfm1:i386 1.0.7-2 i386 Last.fm web services library rc libnetfilter-queue1 1.0.2-1 i386 Netfilter netlink-queue library rc libnl1:i386 1.1-7ubuntu1 i386 library for dealing with netlink sockets rc libossp-uuid16 1.6.2-1.3 i386 OSSP uuid ISO-C and C++ - shared library rc libpackagekit-glib2-14:i386 0.7.6-3ubuntu1 i386 Library for accessing PackageKit using GLib rc libpoppler28:i386 0.20.5-1ubuntu3 i386 PDF rendering library rc libprojectm2 2.1.0+dfsg-1build1 i386 Advanced Milkdrop-compatible music visualization library rc libqxt-core0:i386 0.6.1-7 i386 extensions to Qt core classes (LibQxt) rc libqxt-gui0:i386 0.6.1-7 i386 extensions to Qt GUI classes (LibQxt) rc libraw5:i386 0.14.7-0ubuntu1.13.04.2 i386 raw image decoder library rc librhythmbox-core6 2.98-0ubuntu5 i386 support library for the rhythmbox music player rc librhythmbox-core7 3.0.1-0~13.10~ppa1 i386 support library for the rhythmbox music player rc libsnmp15 5.4.3~dfsg-2.7ubuntu1 i386 SNMP (Simple Network Management Protocol) library rc libsqlite0 2.8.17-8fakesync1 i386 SQLite shared library rc libsyncdaemon-1.0-1 4.2.0-0ubuntu1 i386 Ubuntu One synchronization daemon library rc libtiff4:i386 3.9.7-2ubuntu1 i386 Tag Image File Format (TIFF) library (old version) rc libunity-core-6.0-5 7.0.0daily13.06.19~13.04-0ubuntu1 i386 Core library for the Unity interface. rc libva-wayland1:i386 1.2.1-0ubuntu0~raring i386 Video Acceleration (VA) API for Linux -- Wayland runtime rc libwayland0:i386 1.0.5-0ubuntu1 i386 wayland compositor infrastructure - shared libraries rc libwebp2:i386 0.1.3-3 i386 Lossy compression of digital photographic images. rc linux-image-3.8.0-19-generic 3.8.0-19.30 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-21-generic 3.8.0-21.32 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-22-generic 3.8.0-22.33 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-26-generic 3.8.0-26.38 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-27-generic 3.8.0-27.40 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.9.0-030900-generic 3.9.0-030900.201304291257 i386 Linux kernel image for version 3.9.0 on 32 bit x86 SMP rc linux-image-3.9.0-030900rc8-generic 3.9.0-030900rc8.201304211835 i386 Linux kernel image for version 3.9.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-19-generic 3.8.0-19.30 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-21-generic 3.8.0-21.32 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-22-generic 3.8.0-22.33 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-26-generic 3.8.0-26.38 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-27-generic 3.8.0-27.40 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc preload 0.6.4-2 i386 adaptive readahead daemon rc steam-launcher 1.0.0.39 all Launcher for the Steam software distribution service rc super-boot-manager 0.7.15 all Simple gui to configure Grub2, Burg and Plymouth. rc totem 3.6.3-0ubuntu6 i386 Simple media player for the GNOME desktop based on GStreamer rc transmission-gtk 2.77-0ubuntu1 i386 lightweight BitTorrent client (GTK interface) rc unity-common 7.0.0daily13.06.19~13.04-0ubuntu1 all Common files for the Unity interface. rc vino 3.6.2-0ubuntu4 i386 VNC server for GNOME rc wicd-daemon 1.7.2.4-4.1 all wired and wireless network manager - daemon rc wicd-gtk 1.7.2.4-4.1 all wired and wireless network manager - GTK+ client rc xscreensaver 5.15-2ubuntu1 i386 Automatic screensaver for X rc xscreensaver-data 5.15-3ubuntu1 i386 data files to be shared among screensaver frontends sudo dpkg -l | grep uget: ii uget 1.10.3-1 i386 easy-to-use download manager written in GTK+ sudo dpkg -l | grep indicator: ii gir1.2-appindicator3-0.1 12.10.1+13.10.20130920-0ubuntu2 i386 Typelib files for libappindicator3-1. ii gir1.2-syncmenu-0.1 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status - bindings ii indicator-applet-complete 12.10.2+13.10.20130924.2-0ubuntu1 i386 Clone of the GNOME panel indicator applet ii indicator-application 12.10.1daily13.01.25-0ubuntu1 i386 Application Indicators ii indicator-appmenu 13.01.0+13.10.20130930-0ubuntu1 i386 Indicator for application menus. ii indicator-bluetooth 0.0.6+13.10.20131016-0ubuntu1 i386 System bluetooth indicator. ii indicator-datetime 13.10.0+13.10.20131023.2-0ubuntu1 i386 Simple clock ii indicator-keyboard 0.0.0+13.10.20131010.1-0ubuntu1 i386 Keyboard indicator ii indicator-messages 13.10.1+13.10.20131011-0ubuntu1 i386 indicator that collects messages that need a response ii indicator-multiload 0.3-0ubuntu1 i386 Graphical system load indicator for CPU, ram, etc. ii indicator-power 12.10.6+13.10.20131008-0ubuntu1 i386 Indicator showing power state. ii indicator-printers 0.1.7daily13.03.01-0ubuntu1 i386 indicator showing active print jobs ii indicator-session 12.10.5+13.10.20131023.1-0ubuntu1 i386 indicator showing session management, status and user switching ii indicator-sound 12.10.2+13.10.20131011-0ubuntu1 i386 System sound indicator. ii indicator-sync 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status ii libappindicator1 12.10.1+13.10.20130920-0ubuntu2 i386 Application Indicators ii libappindicator3-1 12.10.1+13.10.20130920-0ubuntu2 i386 Application Indicators ii libindicator3-7 12.10.2+13.10.20130913-0ubuntu2 i386 panel indicator applet - shared library ii libindicator7 12.10.2+13.10.20130913-0ubuntu2 i386 panel indicator applet - shared library ii libsync-menu1:i386 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status - libraries ii python-appindicator 12.10.1+13.10.20130920-0ubuntu2 i386 Python bindings for libappindicator ii sni-qt:i386 0.2.6-0ubuntu1 i386 indicator support for Qt ii telepathy-indicator 0.3.1daily13.06.19-0ubuntu1 i386 Desktop service to integrate Telepathy with the messaging menu.

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  • Investigation: Can different combinations of components effect Dataflow performance?

    - by jamiet
    Introduction The Dataflow task is one of the core components (if not the core component) of SQL Server Integration Services (SSIS) and often the most misunderstood. This is not surprising, its an incredibly complicated beast and we’re abstracted away from that complexity via some boxes that go yellow red or green and that have some lines drawn between them. Example dataflow In this blog post I intend to look under that facade and get into some of the nuts and bolts of the Dataflow Task by investigating how the decisions we make when building our packages can affect performance. I will do this by comparing the performance of three dataflows that all have the same input, all produce the same output, but which all operate slightly differently by way of having different transformation components. I also want to use this blog post to challenge a common held opinion that I see perpetuated over and over again on the SSIS forum. That is, that people assume adding components to a dataflow will be detrimental to overall performance. Its not surprising that people think this –it is intuitive to think that more components means more work- however this is not a view that I share. I have always been of the opinion that there are many factors affecting dataflow duration and the number of components is actually one of the less important ones; having said that I have never proven that assertion and that is one reason for this investigation. I have actually seen evidence that some people think dataflow duration is simply a function of number of rows and number of components. I’ll happily call that one out as a myth even without any investigation!  The Setup I have a 2GB datafile which is a list of 4731904 (~4.7million) customer records with various attributes against them and it contains 2 columns that I am going to use for categorisation: [YearlyIncome] [BirthDate] The data file is a SSIS raw format file which I chose to use because it is the quickest way of getting data into a dataflow and given that I am testing the transformations, not the source or destination adapters, I want to minimise external influences as much as possible. In the test I will split the customers according to month of birth (12 of those) and whether or not their yearly income is above or below 50000 (2 of those); in other words I will be splitting them into 24 discrete categories and in order to do it I shall be using different combinations of SSIS’ Conditional Split and Derived Column transformation components. The 24 datapaths that occur will each input to a rowcount component, again because this is the least resource intensive means of terminating a datapath. The test is being carried out on a Dell XPS Studio laptop with a quad core (8 logical Procs) Intel Core i7 at 1.73GHz and Samsung SSD hard drive. Its running SQL Server 2008 R2 on Windows 7. The Variables Here are the three combinations of components that I am going to test:     One Conditional Split - A single Conditional Split component CSPL Split by Month of Birth and income category that will use expressions on [YearlyIncome] & [BirthDate] to send each row to one of 24 outputs. This next screenshot displays the expression logic in use: Derived Column & Conditional Split - A Derived Column component DER Income Category that adds a new column [IncomeCategory] which will contain one of two possible text values {“LessThan50000”,”GreaterThan50000”} and uses [YearlyIncome] to determine which value each row should get. A Conditional Split component CSPL Split by Month of Birth and Income Category then uses that new column in conjunction with [BirthDate] to determine which of the same 24 outputs to send each row to. Put more simply, I am separating the Conditional Split of #1 into a Derived Column and a Conditional Split. The next screenshots display the expression logic in use: DER Income Category         CSPL Split by Month of Birth and Income Category       Three Conditional Splits - A Conditional Split component that produces two outputs based on [YearlyIncome], one for each Income Category. Each of those outputs will go to a further Conditional Split that splits the input into 12 outputs, one for each month of birth (identical logic in each). In this case then I am separating the single Conditional Split of #1 into three Conditional Split components. The next screenshots display the expression logic in use: CSPL Split by Income Category         CSPL Split by Month of Birth 1& 2       Each of these combinations will provide an input to one of the 24 rowcount components, just the same as before. For illustration here is a screenshot of the dataflow containing three Conditional Split components: As you can these dataflows have a fair bit of work to do and remember that they’re doing that work for 4.7million rows. I will execute each dataflow 10 times and use the average for comparison. I foresee three possible outcomes: The dataflow containing just one Conditional Split (i.e. #1) will be quicker There is no significant difference between any of them One of the two dataflows containing multiple transformation components will be quicker Regardless of which of those outcomes come to pass we will have learnt something and that makes this an interesting test to carry out. Note that I will be executing the dataflows using dtexec.exe rather than hitting F5 within BIDS. The Results and Analysis The table below shows all of the executions, 10 for each dataflow. It also shows the average for each along with a standard deviation. All durations are in seconds. I’m pasting a screenshot because I frankly can’t be bothered with the faffing about needed to make a presentable HTML table. It is plain to see from the average that the dataflow containing three conditional splits is significantly faster, the other two taking 43% and 52% longer respectively. This seems strange though, right? Why does the dataflow containing the most components outperform the other two by such a big margin? The answer is actually quite logical when you put some thought into it and I’ll explain that below. Before progressing, a side note. The standard deviation for the “Three Conditional Splits” dataflow is orders of magnitude smaller – indicating that performance for this dataflow can be predicted with much greater confidence too. The Explanation I refer you to the screenshot above that shows how CSPL Split by Month of Birth and salary category in the first dataflow is setup. Observe that there is a case for each combination of Month Of Date and Income Category – 24 in total. These expressions get evaluated in the order that they appear and hence if we assume that Month of Date and Income Category are uniformly distributed in the dataset we can deduce that the expected number of expression evaluations for each row is 12.5 i.e. 1 (the minimum) + 24 (the maximum) divided by 2 = 12.5. Now take a look at the screenshots for the second dataflow. We are doing one expression evaluation in DER Income Category and we have the same 24 cases in CSPL Split by Month of Birth and Income Category as we had before, only the expression differs slightly. In this case then we have 1 + 12.5 = 13.5 expected evaluations for each row – that would account for the slightly longer average execution time for this dataflow. Now onto the third dataflow, the quick one. CSPL Split by Income Category does a maximum of 2 expression evaluations thus the expected number of evaluations per row is 1.5. CSPL Split by Month of Birth 1 & CSPL Split by Month of Birth 2 both have less work to do than the previous Conditional Split components because they only have 12 cases to test for thus the expected number of expression evaluations is 6.5 There are two of them so total expected number of expression evaluations for this dataflow is 6.5 + 6.5 + 1.5 = 14.5. 14.5 is still more than 12.5 & 13.5 though so why is the third dataflow so much quicker? Simple, the conditional expressions in the first two dataflows have two boolean predicates to evaluate – one for Income Category and one for Month of Birth; the expressions in the Conditional Split in the third dataflow however only have one predicate thus they are doing a lot less work. To sum up, the difference in execution times can be attributed to the difference between: MONTH(BirthDate) == 1 && YearlyIncome <= 50000 and MONTH(BirthDate) == 1 In the first two dataflows YearlyIncome <= 50000 gets evaluated an average of 12.5 times for every row whereas in the third dataflow it is evaluated once and once only. Multiply those 11.5 extra operations by 4.7million rows and you get a significant amount of extra CPU cycles – that’s where our duration difference comes from. The Wrap-up The obvious point here is that adding new components to a dataflow isn’t necessarily going to make it go any slower, moreover you may be able to achieve significant improvements by splitting logic over multiple components rather than one. Performance tuning is all about reducing the amount of work that needs to be done and that doesn’t necessarily mean use less components, indeed sometimes you may be able to reduce workload in ways that aren’t immediately obvious as I think I have proven here. Of course there are many variables in play here and your mileage will most definitely vary. I encourage you to download the package and see if you get similar results – let me know in the comments. The package contains all three dataflows plus a fourth dataflow that will create the 2GB raw file for you (you will also need the [AdventureWorksDW2008] sample database from which to source the data); simply disable all dataflows except the one you want to test before executing the package and remember, execute using dtexec, not within BIDS. If you want to explore dataflow performance tuning in more detail then here are some links you might want to check out: Inequality joins, Asynchronous transformations and Lookups Destination Adapter Comparison Don’t turn the dataflow into a cursor SSIS Dataflow – Designing for performance (webinar) Any comments? Let me know! @Jamiet

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  • Extreme Optimization –Mathematical Constants and Basic Functions

    - by JoshReuben
    Machine constants The MachineConstants class - contains constants for floating-point arithmetic because the CLS System.Single and Double floating-point types do not follow the standard conventions and are useless. machine constants for the Double type: machine precision: Epsilon , SqrtEpsilon CubeRootEpsilon largest possible value: MaxDouble , SqrtMaxDouble, LogMaxDouble smallest Double-precision floating point number that is greater than zero: MinDouble , SqrtMinDouble , LogMinDouble A similar set of constants is available for the Single Datatype  Mathematical Constants The Constants class contains static fields for many mathematical constants and common expressions involving small integers – if you are doing thousands of iterations, you wouldn't want to calculate OneOverSqrtTwoPi , Sqrt17 or Log17 !!! Fundamental constants E - The base for the natural logarithm, e (2.718...). EulersConstant - (0.577...). GoldenRatio - (1.618...). Pi - the ratio between the circumference and the diameter of a circle (3.1415...). Expressions involving fundamental constants: TwoPi, PiOverTwo, PiOverFour, LogTwoPi, PiSquared, SqrPi, SqrtTwoPi, OneOverSqrtPi, OneOverSqrtTwoPi Square roots of small integers: Sqrt2, Sqrt3, Sqrt5, Sqrt7, Sqrt17 Logarithms of small integers: Log2, Log3, Log10, Log17, InvLog10  Elementary Functions The IterativeAlgorithm<T> class in the Extreme.Mathematics namespace defines many elementary functions that are missing from System.Math. Hyperbolic Trig Functions: Cosh, Coth, Csch, Sinh, Sech, Tanh Inverse Hyperbolic Trig Functions: Acosh, Acoth, Acsch, Asinh, Asech, Atanh Exponential, Logarithmic and Miscellaneous Functions: ExpMinus1 - The exponential function minus one, ex-1. Hypot - The hypotenuse of a right-angled triangle with specified sides. LambertW - Lambert's W function, the (real) solution W of x=WeW. Log1PlusX - The natural logarithm of 1+x. Pow - A number raised to an integer power.

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