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  • How much info can I store in a cookie?

    - by Artemix
    Hi guys, Im developing a flash game and I'd like to know how much info can I store in a browser cookie. The game is simple, but it needs to store several variables in order to save all the details of your current progress. The game is only one swf file, no server, no nothing. I need to know how should I use the cookies to achieve this, and if they have the posibility of doing it, of course. (several = 200 variables i.e)

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  • Making game constants/tables available to game logic classes/routines in a modular manner

    - by Extrakun
    Suppose I have a game where there are several predefined constants and charts (a XP chart, cost of goods and so on). Those could be defined at runtime, or load from files at start-up. The question is how should those logic routines access the constants and charts? For example, I could try using global variables, but that cause all classes relying on the variables to be tightly coupled with them.

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  • Cross compilation of udns for power pc

    - by pragya
    I have libraries of x86 architecture that I want to cross compile for power pc. I have already cross compiled different libraries for power pc by setting environment variables for powerpc and using appropriate options with ./configure. Now, I want to cross compile libudns for powerpc. In ./configure --help I am not getting those appropriate options to cross compile. For libudns, I set environment variables for powerpc and ran ./configure but it throws following error: configure: fatal: $CC (powerpc-linux-gnu-gcc) is not a working compiler

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  • Several New Hints

    - by Ondrej Brejla
    Hi all! Today we would like to introduce you some of our new experimental hints for NetBeans 7.2. They are called: Unused Use Statement and Immutable Variables. Unused Use Statement This hint is quite simple. It highlights (underlines) your use statements, which are not used. Typical use case is after some refactoring, when you forgot to remove some obsolete use statements. This hint warns you on them and allows you to remove them easily. Just click on the hint bulb in the gutter and select Remove Unused Use Statement. And of course, it works in multiple use statements combined too. Immutable Variables The next one is the hint which checks too many assignments into a variable. And why? That's simple. Mostly you should use just one assignment into one variable. But sometimes you are lazy and you do something like: But it's quite wrong, because what you really do is: And that's exactly the case, when our new hint warns you, that Too many assignments (2) into variable $foo occured. Nothing more. Yes, we know that there are some cases, where could be more assignments and no warning should occur, e.g.: Because maybe one likes longer increment syntax more than the short one. So we tried to handle these cases to don't bother you if it's not a need. Note: We are almost sure that this hint doesn't cover all your use cases, because there are a lot of them. So if you find something strange, write it into our bugzilla so we can handle it better for you. Thanks for your patience! And the last thing is, that you can set the number of allowed assignments in Tools -> Options -> Editor -> Hints -> PHP: Immutable Variables. Note: This hint works just for a common variables, not for fields. We have an enhancement request for that and it should be implemented in next version of NetBeans (probably 7.3). And that's all for today and as usual, please test it and if you find something strange, don't hesitate to file a new issue (product php, component Editor). Thanks.

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  • Can I show a table of one custom variable against another?

    - by Simon
    We have a number of custom variables set up in google analytics. We'd like to show a table of event occurrences broken down by two custom variables, e.g. if variable one can be A, B, or C and variable two can be J, K or L: Events | A | B | C | -------+-----+-----+-----+ J | 345 | 65 | 12 | K | 234 | 43 | 7 | L | 123 | 21 | 4 | -------+-----+-----+-----+ How do I get the information in that format?

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  • Temporary Object Caching Explained

    - by Paul White
    SQL Server 2005 onward caches temporary tables and table variables referenced in stored procedures for reuse, reducing contention on tempdb allocation structures and catalogue tables.  A number of things can prevent this caching (none of which are allowed when working with table variables): Named constraints (bad idea anyway, since concurrent executions can cause a name collision) DDL after creation (though what is considered DDL is interesting) Creation using dynamic SQL Table created in a...(read more)

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  • Create simple jQuery plugin

    - by ybbest
    In the last post, I have shown you how to add the function to jQuery. In this post, I will show you how to create plugin to achieve this. 1. You need to wrap your code in the following construct, this is because you should not use $ directly as $ is global variable, it could have clash with some other library which also use $.Basically, you can pass in jQuery object into the function, so that $ is made available inside the function. (JavaScript use function to create scope, so you can make sure $ is referred to jQuery inside the function ) (function($){ //Your code goes here. }; })(jQuery); 2. Put your code into the construct above. (function ($) { $.getParameterByName = function (name) { name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]"); var regexS = "[\\?&]" + name + "=([^&#]*)"; var regex = new RegExp(regexS); var results = regex.exec(window.location.search); if (results == null) return ""; else return decodeURIComponent(results[1].replace(/\+/g, " ")); }; })(jQuery); 3. Now you can reference the code into you project and you can call the method in you JavaScript References: Provides scope for variables Variables are scoped at the function level in javascript. This is different to what you might be used to in a language like C# or Java where the variables are scoped to the block. What this means is if you declare a variable inside a loop or an if statement, it will be available to the entire function. If you ever find yourself needing to explicitly scope a variable inside a function you can use an anonymous function to do this. You can actually create an anonymous function and then execute it straight away and all the variables inside will be scoped to the anonymous function: (function() { var myProperty = "hello world"; alert(myProperty); })(); alert(typeof(myProperty)); // undefined How does an anonymous function in JavaScript work? Building Your First jQuery Plugin A Plugin Development Pattern

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  • Comment Déboguer les procédures, fonctions et triggers sous SSMS 2008, par hmira

    hmira nous propose un article qui explique comment déboguer une procédure stockée, une fonction ou un trigger sous SSMS 2008 (SQL Server 2008 Management Studio). Celui-ci décrit la manière de définir des points d'arrêts, faire du pas à pas dans les blocs T-SQL, consulter le contenu des variables locales et variables systèmes @@, etc.. Merci à lui >> Pour plus de détails Vos remarques et suggestions sont les biens venus. A+...

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  • SEO - The Nuts and Bolts

    This article outlines the major variables a successful website owner should take into consideration when attempting to align their website with the algorithms the search engines use to determine a page's overall relevance. These variables include: Keywords (contained within the metatags as well as within the content of the site), regular XML Sitemap creation and periodic submission to the search engines, Domain Name and Age, and finally backlinking or reciprocal linking to a handful of relevant and viable sites.

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  • Tip/Trick: Fix Common SEO Problems Using the URL Rewrite Extension

    - by ScottGu
    Search engine optimization (SEO) is important for any publically facing web-site.  A large % of traffic to sites now comes directly from search engines, and improving your site’s search relevancy will lead to more users visiting your site from search engine queries.  This can directly or indirectly increase the money you make through your site. This blog post covers how you can use the free Microsoft URL Rewrite Extension to fix a bunch of common SEO problems that your site might have.  It takes less than 15 minutes (and no code changes) to apply 4 simple URL Rewrite rules to your site, and in doing so cause search engines to drive more visitors and traffic to your site.  The techniques below work equally well with both ASP.NET Web Forms and ASP.NET MVC based sites.  They also works with all versions of ASP.NET (and even work with non-ASP.NET content). [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Measuring the SEO of your website with the Microsoft SEO Toolkit A few months ago I blogged about the free SEO Toolkit that we’ve shipped.  This useful tool enables you to automatically crawl/scan your site for SEO correctness, and it then flags any SEO issues it finds.  I highly recommend downloading and using the tool against any public site you work on.  It makes it easy to spot SEO issues you might have in your site, and pinpoint ways to optimize it further. Below is a simple example of a report I ran against one of my sites (www.scottgu.com) prior to applying the URL Rewrite rules I’ll cover later in this blog post:   Search Relevancy and URL Splitting Two of the important things that search engines evaluate when assessing your site’s “search relevancy” are: How many other sites link to your content.  Search engines assume that if a lot of people around the web are linking to your content, then it is likely useful and so weight it higher in relevancy. The uniqueness of the content it finds on your site.  If search engines find that the content is duplicated in multiple places around the Internet (or on multiple URLs on your site) then it is likely to drop the relevancy of the content. One of the things you want to be very careful to avoid when building public facing sites is to not allow different URLs to retrieve the same content within your site.  Doing so will hurt with both of the situations above.  In particular, allowing external sites to link to the same content with multiple URLs will cause your link-count and page-ranking to be split up across those different URLs (and so give you a smaller page rank than what it would otherwise be if it was just one URL).  Not allowing external sites to link to you in different ways sounds easy in theory – but you might wonder what exactly this means in practice and how you avoid it. 4 Really Common SEO Problems Your Sites Might Have Below are 4 really common scenarios that can cause your site to inadvertently expose multiple URLs for the same content.  When this happens external sites linking to yours will end up splitting their page links across multiple URLs - and as a result cause you to have a lower page ranking with search engines than you deserve. SEO Problem #1: Default Document IIS (and other web servers) supports the concept of a “default document”.  This allows you to avoid having to explicitly specify the page you want to serve at either the root of the web-site/application, or within a sub-directory.  This is convenient – but means that by default this content is available via two different publically exposed URLs (which is bad).  For example: http://scottgu.com/ http://scottgu.com/default.aspx SEO Problem #2: Different URL Casings Web developers often don’t realize URLs are case sensitive to search engines on the web.  This means that search engines will treat the following links as two completely different URLs: http://scottgu.com/Albums.aspx http://scottgu.com/albums.aspx SEO Problem #3: Trailing Slashes Consider the below two URLs – they might look the same at first, but they are subtly different. The trailing slash creates yet another situation that causes search engines to treat the URLs as different and so split search rankings: http://scottgu.com http://scottgu.com/ SEO Problem #4: Canonical Host Names Sometimes sites support scenarios where they support a web-site with both a leading “www” hostname prefix as well as just the hostname itself.  This causes search engines to treat the URLs as different and split search rankling: http://scottgu.com/albums.aspx/ http://www.scottgu.com/albums.aspx/ How to Easily Fix these SEO Problems in 10 minutes (or less) using IIS Rewrite If you haven’t been careful when coding your sites, chances are you are suffering from one (or more) of the above SEO problems.  Addressing these issues will improve your search engine relevancy ranking and drive more traffic to your site. The “good news” is that fixing the above 4 issues is really easy using the URL Rewrite Extension.  This is a completely free Microsoft extension available for IIS 7.x (on Windows Server 2008, Windows Server 2008 R2, Windows 7 and Windows Vista).  The great thing about using the IIS Rewrite extension is that it allows you to fix the above problems *without* having to change any code within your applications.  You can easily install the URL Rewrite Extension in under 3 minutes using the Microsoft Web Platform Installer (a free tool we ship that automates setting up web servers and development machines).  Just click the green “Install Now” button on the URL Rewrite Spotlight page to install it on your Windows Server 2008, Windows 7 or Windows Vista machine: Once installed you’ll find that a new “URL Rewrite” icon is available within the IIS 7 Admin Tool: Double-clicking the icon will open up the URL Rewrite admin panel – which will display the list of URL Rewrite rules configured for a particular application or site: Notice that our rewrite rule list above is currently empty (which is the default when you first install the extension).  We can click the “Add Rule…” link button in the top-right of the panel to add and enable new URL Rewriting logic for our site.  Scenario 1: Handling Default Document Scenarios One of the SEO problems I discussed earlier in this post was the scenario where the “default document” feature of IIS causes you to inadvertently expose two URLs for the same content on your site.  For example: http://scottgu.com/ http://scottgu.com/default.aspx We can fix this by adding a new IIS Rewrite rule that automatically redirects anyone who navigates to the second URL to instead go to the first one.  We will setup the HTTP redirect to be a “permanent redirect” – which will indicate to search engines that they should follow the redirect and use the new URL they are redirected to as the identifier of the content they retrieve.  Let’s look at how we can create such a rule.  We’ll begin by clicking the “Add Rule” link in the screenshot above.  This will cause the below dialog to display: We’ll select the “Blank Rule” template within the “Inbound rules” section to create a new custom URL Rewriting rule.  This will display an empty pane like below: Don’t worry – setting up the above rule is easy.  The following 4 steps explain how to do so: Step 1: Name the Rule Our first step will be to name the rule we are creating.  Naming it with a descriptive name will make it easier to find and understand later.  Let’s name this rule our “Default Document URL Rewrite” rule: Step 2: Setup the Regular Expression that Matches this Rule Our second step will be to specify a regular expression filter that will cause this rule to execute when an incoming URL matches the regex pattern.   Don’t worry if you aren’t good with regular expressions - I suck at them too. The trick is to know someone who is good at them or copy/paste them from a web-site.  Below we are going to specify the following regular expression as our pattern rule: (.*?)/?Default\.aspx$ This pattern will match any URL string that ends with Default.aspx. The "(.*?)" matches any preceding character zero or more times. The "/?" part says to match the slash symbol zero or one times. The "$" symbol at the end will ensure that the pattern will only match strings that end with Default.aspx.  Combining all these regex elements allows this rule to work not only for the root of your web site (e.g. http://scottgu.com/default.aspx) but also for any application or subdirectory within the site (e.g. http://scottgu.com/photos/default.aspx.  Because the “ignore case” checkbox is selected it will match both “Default.aspx” as well as “default.aspx” within the URL.   One nice feature built-into the rule editor is a “Test pattern” button that you can click to bring up a dialog that allows you to test out a few URLs with the rule you are configuring: Above I've added a “products/default.aspx” URL and clicked the “Test” button.  This will give me immediate feedback on whether the rule will execute for it.  Step 3: Setup a Permanent Redirect Action We’ll then setup an action to occur when our regular expression pattern matches the incoming URL: In the dialog above I’ve changed the “Action Type” drop down to be a “Redirect” action.  The “Redirect Type” will be a HTTP 301 Permanent redirect – which means search engines will follow it. I’ve also set the “Redirect URL” property to be: {R:1}/ This indicates that we want to redirect the web client requesting the original URL to a new URL that has the originally requested URL path - minus the "Default.aspx" in it.  For example, requests for http://scottgu.com/default.aspx will be redirected to http://scottgu.com/, and requests for http://scottgu.com/photos/default.aspx will be redirected to http://scottgu.com/photos/ The "{R:N}" regex construct, where N >= 0, is called a back-reference and N is the back-reference index. In the case of our pattern "(.*?)/?Default\.aspx$", if the input URL is "products/Default.aspx" then {R:0} will contain "products/Default.aspx" and {R:1} will contain "products".  We are going to use this {R:1}/ value to be the URL we redirect users to.  Step 4: Apply and Save the Rule Our final step is to click the “Apply” button in the top right hand of the IIS admin tool – which will cause the tool to persist the URL Rewrite rule into our application’s root web.config file (under a <system.webServer/rewrite> configuration section): <configuration>     <system.webServer>         <rewrite>             <rules>                 <rule name="Default Document" stopProcessing="true">                     <match url="(.*?)/?Default\.aspx$" />                     <action type="Redirect" url="{R:1}/" />                 </rule>             </rules>         </rewrite>     </system.webServer> </configuration> Because IIS 7.x and ASP.NET share the same web.config files, you can actually just copy/paste the above code into your web.config files using Visual Studio and skip the need to run the admin tool entirely.  This also makes adding/deploying URL Rewrite rules with your ASP.NET applications really easy. Step 5: Try the Rule Out Now that we’ve saved the rule, let’s try it out on our site.  Try the following two URLs on my site: http://scottgu.com/ http://scottgu.com/default.aspx Notice that the second URL automatically redirects to the first one.  Because it is a permanent redirect, search engines will follow the URL and should update the page ranking of http://scottgu.com to include links to http://scottgu.com/default.aspx as well. Scenario 2: Different URL Casing Another common SEO problem I discussed earlier in this post is that URLs are case sensitive to search engines on the web.  This means that search engines will treat the following links as two completely different URLs: http://scottgu.com/Albums.aspx http://scottgu.com/albums.aspx We can fix this by adding a new IIS Rewrite rule that automatically redirects anyone who navigates to the first URL to instead go to the second (all lower-case) one.  Like before, we will setup the HTTP redirect to be a “permanent redirect” – which will indicate to search engines that they should follow the redirect and use the new URL they are redirected to as the identifier of the content they retrieve. To create such a rule we’ll click the “Add Rule” link in the URL Rewrite admin tool again.  This will cause the “Add Rule” dialog to appear again: Unlike the previous scenario (where we created a “Blank Rule”), with this scenario we can take advantage of a built-in “Enforce lowercase URLs” rule template.  When we click the “ok” button we’ll see the following dialog which asks us if we want to create a rule that enforces the use of lowercase letters in URLs: When we click the “Yes” button we’ll get a pre-written rule that automatically performs a permanent redirect if an incoming URL has upper-case characters in it – and automatically send users to a lower-case version of the URL: We can click the “Apply” button to use this rule “as-is” and have it apply to all incoming URLs to our site.  Because my www.scottgu.com site uses ASP.NET Web Forms, I’m going to make one small change to the rule we generated above – which is to add a condition that will ensure that URLs to ASP.NET’s built-in “WebResource.axd” handler are excluded from our case-sensitivity URL Rewrite logic.  URLs to the WebResource.axd handler will only come from server-controls emitted from my pages – and will never be linked to from external sites.  While my site will continue to function fine if we redirect these URLs to automatically be lower-case – doing so isn’t necessary and will add an extra HTTP redirect to many of my pages.  The good news is that adding a condition that prevents my URL Rewriting rule from happening with certain URLs is easy.  We simply need to expand the “Conditions” section of the form above We can then click the “Add” button to add a condition clause.  This will bring up the “Add Condition” dialog: Above I’ve entered {URL} as the Condition input – and said that this rule should only execute if the URL does not match a regex pattern which contains the string “WebResource.axd”.  This will ensure that WebResource.axd URLs to my site will be allowed to execute just fine without having the URL be re-written to be all lower-case. Note: If you have static resources (like references to .jpg, .css, and .js files) within your site that currently use upper-case characters you’ll probably want to add additional condition filter clauses so that URLs to them also don’t get redirected to be lower-case (just add rules for patterns like .jpg, .gif, .js, etc).  Your site will continue to work fine if these URLs get redirected to be lower case (meaning the site won’t break) – but it will cause an extra HTTP redirect to happen on your site for URLs that don’t need to be redirected for SEO reasons.  So setting up a condition clause makes sense to add. When I click the “ok” button above and apply our lower-case rewriting rule the admin tool will save the following additional rule to our web.config file: <configuration>     <system.webServer>         <rewrite>             <rules>                 <rule name="Default Document" stopProcessing="true">                     <match url="(.*?)/?Default\.aspx$" />                     <action type="Redirect" url="{R:1}/" />                 </rule>                 <rule name="Lower Case URLs" stopProcessing="true">                     <match url="[A-Z]" ignoreCase="false" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{URL}" pattern="WebResource.axd" negate="true" />                     </conditions>                     <action type="Redirect" url="{ToLower:{URL}}" />                 </rule>             </rules>         </rewrite>     </system.webServer> </configuration> Try the Rule Out Now that we’ve saved the rule, let’s try it out on our site.  Try the following two URLs on my site: http://scottgu.com/Albums.aspx http://scottgu.com/albums.aspx Notice that the first URL (which has a capital “A”) automatically does a redirect to a lower-case version of the URL.  Scenario 3: Trailing Slashes Another common SEO problem I discussed earlier in this post is the scenario of trailing slashes within URLs.  The trailing slash creates yet another situation that causes search engines to treat the URLs as different and so split search rankings: http://scottgu.com http://scottgu.com/ We can fix this by adding a new IIS Rewrite rule that automatically redirects anyone who navigates to the first URL (that does not have a trailing slash) to instead go to the second one that does.  Like before, we will setup the HTTP redirect to be a “permanent redirect” – which will indicate to search engines that they should follow the redirect and use the new URL they are redirected to as the identifier of the content they retrieve.  To create such a rule we’ll click the “Add Rule” link in the URL Rewrite admin tool again.  This will cause the “Add Rule” dialog to appear again: The URL Rewrite admin tool has a built-in “Append or remove the trailing slash symbol” rule template.  When we select it and click the “ok” button we’ll see the following dialog which asks us if we want to create a rule that automatically redirects users to a URL with a trailing slash if one isn’t present: Like within our previous lower-casing rewrite rule we’ll add one additional condition clause that will exclude WebResource.axd URLs from being processed by this rule.  This will avoid an unnecessary redirect for happening for those URLs. When we click the “OK” button we’ll get a pre-written rule that automatically performs a permanent redirect if the URL doesn’t have a trailing slash – and if the URL is not processed by either a directory or a file.  This will save the following additional rule to our web.config file: <configuration>     <system.webServer>         <rewrite>             <rules>                 <rule name="Default Document" stopProcessing="true">                     <match url="(.*?)/?Default\.aspx$" />                     <action type="Redirect" url="{R:1}/" />                 </rule>                 <rule name="Lower Case URLs" stopProcessing="true">                     <match url="[A-Z]" ignoreCase="false" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{URL}" pattern="WebResource.axd" negate="true" />                     </conditions>                     <action type="Redirect" url="{ToLower:{URL}}" />                 </rule>                 <rule name="Trailing Slash" stopProcessing="true">                     <match url="(.*[^/])$" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />                         <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />                         <add input="{URL}" pattern="WebResource.axd" negate="true" />                     </conditions>                     <action type="Redirect" url="{R:1}/" />                 </rule>             </rules>         </rewrite>     </system.webServer> </configuration> Try the Rule Out Now that we’ve saved the rule, let’s try it out on our site.  Try the following two URLs on my site: http://scottgu.com http://scottgu.com/ Notice that the first URL (which has no trailing slash) automatically does a redirect to a URL with the trailing slash.  Because it is a permanent redirect, search engines will follow the URL and update the page ranking. Scenario 4: Canonical Host Names The final SEO problem I discussed earlier are scenarios where a site works with both a leading “www” hostname prefix as well as just the hostname itself.  This causes search engines to treat the URLs as different and split search rankling: http://www.scottgu.com/albums.aspx http://scottgu.com/albums.aspx We can fix this by adding a new IIS Rewrite rule that automatically redirects anyone who navigates to the first URL (that has a www prefix) to instead go to the second URL.  Like before, we will setup the HTTP redirect to be a “permanent redirect” – which will indicate to search engines that they should follow the redirect and use the new URL they are redirected to as the identifier of the content they retrieve.  To create such a rule we’ll click the “Add Rule” link in the URL Rewrite admin tool again.  This will cause the “Add Rule” dialog to appear again: The URL Rewrite admin tool has a built-in “Canonical domain name” rule template.  When we select it and click the “ok” button we’ll see the following dialog which asks us if we want to create a redirect rule that automatically redirects users to a primary host name URL: Above I’m entering the primary URL address I want to expose to the web: scottgu.com.  When we click the “OK” button we’ll get a pre-written rule that automatically performs a permanent redirect if the URL has another leading domain name prefix.  This will save the following additional rule to our web.config file: <configuration>     <system.webServer>         <rewrite>             <rules>                 <rule name="Cannonical Hostname">                     <match url="(.*)" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{HTTP_HOST}" pattern="^scottgu\.com$" negate="true" />                     </conditions>                     <action type="Redirect" url="http://scottgu.com/{R:1}" />                 </rule>                 <rule name="Default Document" stopProcessing="true">                     <match url="(.*?)/?Default\.aspx$" />                     <action type="Redirect" url="{R:1}/" />                 </rule>                 <rule name="Lower Case URLs" stopProcessing="true">                     <match url="[A-Z]" ignoreCase="false" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{URL}" pattern="WebResource.axd" negate="true" />                     </conditions>                     <action type="Redirect" url="{ToLower:{URL}}" />                 </rule>                 <rule name="Trailing Slash" stopProcessing="true">                     <match url="(.*[^/])$" />                     <conditions logicalGrouping="MatchAll" trackAllCaptures="false">                         <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />                         <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />                         <add input="{URL}" pattern="WebResource.axd" negate="true" />                     </conditions>                     <action type="Redirect" url="{R:1}/" />                 </rule>             </rules>         </rewrite>     </system.webServer> </configuration> Try the Rule Out Now that we’ve saved the rule, let’s try it out on our site.  Try the following two URLs on my site: http://www.scottgu.com/albums.aspx http://scottgu.com/albums.aspx Notice that the first URL (which has the “www” prefix) now automatically does a redirect to the second URL which does not have the www prefix.  Because it is a permanent redirect, search engines will follow the URL and update the page ranking. 4 Simple Rules for Improved SEO The above 4 rules are pretty easy to setup and should take less than 15 minutes to configure on existing sites you already have.  The beauty of using a solution like the URL Rewrite Extension is that you can take advantage of it without having to change code within your web-site – and without having to break any existing links already pointing at your site.  Users who follow existing links will be automatically redirected to the new URLs you wish to publish.  And search engines will start to give your site a higher search relevancy ranking – which will list your site higher in search results and drive more traffic to it. Customizing your URL Rewriting rules further is easy to-do either by editing the web.config file directly, or alternatively, just double click the URL Rewrite icon within the IIS 7.x admin tool and it will list all the active rules for your web-site or application: Clicking any of the rules above will open the rules editor back up and allow you to tweak/customize/save them further. Summary Measuring and improving SEO is something every developer building a public-facing web-site needs to think about and focus on.  If you haven’t already, download and use the SEO Toolkit to analyze the SEO of your sites today. New URL Routing features in ASP.NET MVC and ASP.NET Web Forms 4 make it much easier to build applications that have more control over the URLs that are published.  Tools like the URL Rewrite Extension that I’ve talked about in this blog post make it much easier to improve the URLs that are published from sites you already have built today – without requiring you to change a lot of code. The URL Rewrite Extension provides a bunch of additional great capabilities – far beyond just SEO - as well.  I’ll be covering these additional capabilities more in future blog posts. Hope this helps, Scott

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  • Parsing with BeautifulSoup, error message TypeError: coercing to Unicode: need string or buffer, NoneType found

    - by Samsun Knight
    so I'm trying to scrape an Amazon page for data, and I'm getting an error when I try to parse for where the seller is located. Here's my code: #getting the html request = urllib2.Request('http://www.amazon.com/gp/offer-listing/0393934241/') opener = urllib2.build_opener() #hiding that I'm a webscraper request.add_header('User-Agent', 'Mozilla/5 (Solaris 10) Gecko') #opening it up, putting into soup form html = opener.open(request).read() soup = BeautifulSoup(html, "html5lib") #parsing for the seller info sellers = soup.findAll('div', {'class' : 'a-row a-spacing-medium olpOffer'}) for eachseller in sellers: #parsing for price price = eachseller.find('span', {'class' : 'a-size-large a-color-price olpOfferPrice a-text-bold'}) #parsing for shipping costs shippingprice = eachseller.find('span' , {'class' : 'olpShippingPrice'}) #parsing for condition condition = eachseller.find('span', {'class' : 'a-size-medium'}) #parsing for seller name sellername = eachseller.find('b') #parsing for seller location location = eachseller.find('div', {'class' : 'olpAvailability'}) #printing it all out print "price, " + price.string + ", shipping price, " + shippingprice.string + ", condition," + condition.string + ", seller name, " + sellername.string + ", location, " + location.string I get the error message, pertaining to the 'print' command at the end, "TypeError: coercing to Unicode: need string or buffer, NoneType found" I know that it's coming from this line - location = eachseller.find('div', {'class' : 'olpAvailability'}) - because the code works fine without that line, and I know that I'm getting NoneType because the line isn't finding anything. Here's the html from the section I'm looking to parse: <*div class="olpAvailability"> In Stock. Ships from WI, United States. <*br/><*a href="/gp/aag/details/ref=olp_merch_ship_9/175-0430757-3801038?ie=UTF8&amp;asin=0393934241&amp;seller=A1W2IX7T37FAMZ&amp;sshmPath=shipping-rates#aag_shipping">Domestic shipping rates</a> and <*a href="/gp/aag/details/ref=olp_merch_return_9/175-0430757-3801038?ie=UTF8&amp;asin=0393934241&amp;seller=A1W2IX7T37FAMZ&amp;sshmPath=returns#aag_returns">return policy</a>. <*/div> (but without the stars - just making sure the HTML doesn't compile out of code form) I don't see what's the problem with the 'location' line of code, or why it's not pulling the data I want. Help?

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  • trigger config transformation in TFS 2010 or msbuild

    - by grenade
    I'm attempting to make use of configuration transformations in a continuous integration environment. I need a way to tell the TFS build agent to perform the transformations. I was kind of hoping it would just work after discovering the config transform files (web.qa-release.config, web.production-release.config, etc...). But it doesn't. I have a TFS build definition that builds the right configurations (qa-release, production-release, etc...) and I have some specific .proj files that get built within these definitions and those contain some environment specific parameters eg: <PropertyGroup Condition=" '$(Configuration)'=='production-release' "> <TargetHost Condition=" '$(TargetHost)'=='' ">qa.web</TargetHost> ... </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)'=='qa-release' "> <TargetHost Condition=" '$(TargetHost)'=='' ">production.web</TargetHost> ... </PropertyGroup> I know from the output that the correct configurations are being built. Now I just need to learn how to trigger the config transformations. Is there some hocus pocus that I can add to the final .proj in the build to kick off the transform and blow away the individual transform files?

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  • Readability and IF-block brackets: best practice

    - by MasterPeter
    I am preparing a short tutorial for level 1 uni students learning JavaScript basics. The task is to validate a phone number. The number must not contain non-digits and must be 14 digits long or less. The following code excerpt is what I came up with and I would like to make it as readable as possible. if ( //set of rules for invalid phone number phoneNumber.length == 0 //empty || phoneNumber.length > 14 //too long || /\D/.test(phoneNumber) //contains non-digits ) { setMessageText(invalid); } else { setMessageText(valid); } A simple question I can not quite answer myself and would like to hear your opinions on: How to position the surrounding (outermost) brackets? It's hard to see the difference between a normal and a curly bracket. Do you usually put the last ) on the same line as the last condition? Do you keep the first opening ( on a line by itself? Do you wrap each individual sub-condition in brackets too? Do you align horizontally the first ( with the last ), or do you place the last ) in the same column as the if? Do you keep ) { on a separate line or you place the last ) on the same line with the last sub-condition and then place the opening { on a new line? Or do you just put the ) { on the same line as the last sub-condition? Community wiki. EDIT Please only post opinions regarding the usage and placement of brackets. The code needs not be re-factored. This is for people who have only been introduced to JavaScript a couple of weeks ago. I am not asking for opinions how to write the code so it's shorter or performs better. I would only like to know how do you place brackets around IF-conditions.

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  • CPU friendly infinite loop

    - by Adi
    Writing an infinite loop is simple: while(true){ //add whatever break condition here } But this will trash the CPU performance. This execution thread will take as much as possible from CPU's power. What is the best way to lower the impact on CPU? Adding some Thread.Sleep(n) should do the trick, but setting a high timeout value for Sleep() method may indicate an unresponsive application to the operating system. Let's say I need to perform a task each minute or so in a console app. I need to keep Main() running in an "infinite loop" while a timer will fire the event that will do the job. I would like to keep Main() with the lowest impact on CPU. What methods do you suggest. Sleep() can be ok, but as I already mentioned, this might indicate an unresponsive thread to the operating system. LATER EDIT: I want to explain better what I am looking for: I need a console app not Windows service. Console apps can simulate the Windows services on Windows Mobile 6.x systems with Compact Framework. I need a way to keep the app alive as long as the Windows Mobile device is running. We all know that the console app runs as long as its static Main() function runs, so I need a way to prevent Main() function exit. In special situations (like: updating the app), I need to request the app to stop, so I need to infinitely loop and test for some exit condition. For example, this is why Console.ReadLine() is no use for me. There is no exit condition check. Regarding the above, I still want Main() function as resource friendly as possible. Let asside the fingerprint of the function that checks for the exit condition.

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  • Is there a problem with this MySQL Query?

    - by ThinkingInBits
    http://pastie.org/954073 The echos at the top all display valid data that fit the database schema. There are no connection errors Any ideas? Thanks in advance! Here is the echo'ed query INSERT INTO equipment (cat_id, name, year, manufacturer, model, price, location, condition, stock_num, information, description, created, modified) VALUES (1, 'r', 1, 'sdf', 'sdf', '2', 'd', 'd', '3', 'asdfasdfdf', 'df', '10 May 10', '10 May 10') MySQL is giving: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'condition, stock_num, information, description, created, modified) VALUES (1, 'r' at line 1 id int(11) unsigned NO PRI NULL auto_increment Edit Delete cat_id int(11) unsigned NO NULL Edit Delete prod_name varchar(255) YES NULL Edit Delete prod_year varchar(10) YES NULL Edit Delete manufacturer varchar(255) YES NULL Edit Delete model varchar(255) YES NULL Edit Delete price varchar(10) YES NULL Edit Delete location varchar(255) YES NULL Edit Delete condition varchar(25) YES NULL Edit Delete stock_num varchar(128) YES NULL Edit Delete information text YES NULL Edit Delete description text YES NULL Edit Delete created varchar(20) YES NULL Edit Delete modified varchar(20) YES NULL Query: INSERT INTO equipment (cat_id, prod_name, prod_year, manufacturer, model, price, location, condition, stock_num, information, description, created, modified) VALUES (1, 'asdf', '234', 'adf', 'asdf', '34', 'asdf', 'asdf', '234', 'asdf', 'asdf', '10 May 10', '10 May 10')

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  • Filter of Data in Gridview logical error please using asp.net

    - by RajuBabli Abbasi
    I wanted to filter the Data in asp.net but my Data is not filtering i have some logical error So please help me for this case i will be very thanks full to those who will help me please consider my code and replay me with code if you can so please i am waiting for your replay thanks again my asp.cs file is protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { DisplayStudentInformation(); } } private void DisplayStudentInformation() { string filter = "%" + filterTextBox.Text + "%"; if (filter == String.Empty) filter = "%"; try { using (SqlDataReader reader = DAC.GetCompanyInformation(filter)) {//reader.Read(); StudentGridView.DataSource = reader; StudentGridView.DataBind(); } } catch (SqlException ex) { StatusLabel.Text = ex.Message; } } my .aspx file is asp:Table ID="Tabel" runat ="server" asp:TableRow asp:TableCell asp:Label ID="filterLabel" runat ="server" Text ="Company Name Filter:" AssociatedControlID="filterTextBox" /asp:TableCell asp:TableCell asp:TextBox ID="filterTextBox" runat="server" MaxLength ="50" /asp:TableCell asp:TableCell asp:Button ID="refreshButton" runat ="server" Text ="Filter" CausesValidation="false" / /asp:TableCell /asp:TableRow /asp:Table My DAC file is public static SqlDataReader GetCompanyInformation(string filter) { SqlDataReader reader; string sql = "SELECT * FROM Student WHERE LastName LIKE @prmLastName "; using(SqlCommand command = new SqlCommand (sql,ConnectionManager.GetConnection())) {//In ExecuteReader we pass the CommandBehavior as singleResult because we need the Single result and also passing the close connection when Datais retriev // command.Parameters.Add("@prmLastName", SqlDbType.VarChar, 25).Value = filter; command.Parameters.AddWithValue("@prmLastName", filter); reader = command.ExecuteReader(CommandBehavior.SingleResult | CommandBehavior.CloseConnection); } return reader; } Note:- When i don't use the If(!Ispostback) Condition and simply pass the DisplayStudentInformation(); method in my page load then Data can be filter but with If(!IspostBack ) condition which is also important for updating the data and for other purpose . Data can be filter . Se aim of the expert is that Filter the Data in a gridview using condition of IF(!IspostBack ) means without the removing is post back condition Filter the Data . I have been ask other about this question but no body solve this so please help me i will be very thanks full to you all ok

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  • IF-block brackets: best practice

    - by MasterPeter
    I am preparing a short tutorial for level 1 uni students learning JavaScript basics. The task is to validate a phone number. The number must not contain non-digits and must be 14 digits long or less. The following code excerpt is what I came up with and I would like to make it as readable as possible. if ( //set of rules for invalid phone number phoneNumber.length == 0 //empty || phoneNumber.length > 14 //too long || /\D/.test(phoneNumber) //contains non-digits ) { setMessageText(invalid); } else { setMessageText(valid); } A simple question I can not quite answer myself and would like to hear your opinions on: How to position the surrounding (outermost) brackets? It's hard to see the difference between a normal and a curly bracket. Do you usually put the last ) on the same line as the last condition? Do you keep the first opening ( on a line by itself? Do you wrap each individual sub-condition in brackets too? Do you align horizontally the first ( with the last ), or do you place the last ) in the same column as the if? Do you keep ) { on a separate line or you place the last ) on the same line with the last sub-condition and then place the opening { on a new line? Or do you just put the ) { on the same line as the last sub-condition? Community wiki.

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  • How do I generate a connection reset programatically?

    - by Brock Adams
    Hi, I'm sure you've seen the "the connection was reset" message displayed when trying to browse web pages. (The text is from Firefox, other browsers differ.) I need to generate that message/error/condition on demand, to test workarounds. So, how do I generate that condition programmatically? (How to generate a TCP RST from PHP -- or one of the other web-app languages?) Caveats and Conditions: It cannot be a general IP block. The test client must still be able to see the test server when not triggering the condition. Ideally, it would be done at the web-application level (Python, PHP, Coldfusion, Javascript, etc.). Access to routers is problematic. Access to Apache config is a pain. Ideally, it would be triggered by fetching a specific web-page. Bonus if it works on a standard, commercial web host. Update: Sending RST is not enough to cause this condition. See my partial answer, below. I've a solution that works on a local machine, Now need to get it working on a remote host.

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  • Is there "good" PRNG generating values without hidden state?

    - by actual
    I need some good pseudo random number generator that can be computed like a pure function from its previous output without any state hiding. Under "good" I mean: I must be able to parametrize generator in such way that running it for 2^n iterations with any parameters should cover all or almost all values between 0 and 2^n - 1, where n is the number of bits in output value. Combined generator output of n + p bits must cover all or almost all values between 0 and 2^(n + p) - 1 if I run it for 2^n iterations for every possible combination of its parameters, where p is the number of bits in parameters. For example, LCG can be computed like a pure function and it can meet first condition, but it can not meet second one. Say, we have 32-bit generator, m = 2^32 and it is constant, our p = 64 (two 32-bit parameters a and c), n + p = 96, so we must peek data by three ints from output to meet second condition. Unfortunately, condition can not be meet because of strictly alternating sequence of odd and even ints in output. To overcome this, hidden state must be introduced, but that makes function not pure and breaks first condition (period become much longer). Am I wanting too much?

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  • Tracking a fragment of a file in two places with git

    - by mabraham
    Hi, I have code such as void myfunc() { introduction(); while(condition()) { complex(); loop(); interior(); code(); } cleanup(); } which I wish to duplicate into two versions, viz: void myfuncA() { introduction(); minorchangeA(); while(condition()) { complex(); loop(); interior(); code(); } cleanup(); } void myfuncB() { introduction(); minorchangeB(); while(condition()) { complex(); modifiedB(); loop(); interior(); code(); } cleanup(); extracleanupB(); } git claims to track content rather than files, so do I need to tell it that there are chunks here that are common to both myfuncA and myfuncB so that when merging with upstream changes to myfunc that those changes should propagate to both myfuncA and myfuncB? If so, how? The code could be written so that myfuncAB did the correct thing at each point by testing for condition A or B, but that could seriously hinder readability or performance.

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  • Optional mix of filter parameters in a search the Rails way.

    - by GSP
    I've got a simple list page with a couple of search filters status which is a simple enumeration and a test query which I want to compare against both the title and description field of my model. In my controller, I want to do something like this: def index conditions = {} conditions[:status] = params[:status] if params[:status] and !params[:status].empty? conditions[???] = ["(descr = ? or title = ?)", params[:q], params[:q]] if params[:q] and !params[:q].empty? @items = Item.find(:all, :conditions => conditions) end Unfortunately, it doesn't look like I can mix the two types of conditions (the hash and the paramatized version). Is there a "Rails Way" of doing this or do I simply have to do something awful like this: has_status = params[:status] and !params[:status].empty? has_text = params[:q] and !params[:q].empty? if has_status and !has_text # build paramatized condition with just the status elsif has_text and !has_status # build paramatized condition with just the text query elsif has_text and has_status # build paramatized condition with both else # build paramatized condition with neither end I'm migrating from Hibernate and Criteria so forgive me if I'm not thinking of this correctly... Environment: Rails 2.3.4

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  • Tomcat 7 taking ages to start up after upgrade

    - by Lawrence
    I recently updated my server installation from Tomcat 6 to Tomcat 7, in order to take advantage of better connection pooling. My project uses Hibernate, for object persistance, a Mysql 5.5.20 database, and memcached for caching. When I was using Tomcat 6, Tomcat would start in about 8 seconds. After moving to Tomcat 7, it now takes between 75 - 80 seconds to start (this is on a Macbook pro 15", core i7 2Ghz, 8Gb of RAM). The only thing that has really changed between during the move from Tomcat 6 to 7 has been my context.xml file, which controls the connection pooling information: <Context antiJARLocking="true" reloadable="true" path=""> <Resource name="jdbc/test-db" auth="Container" type="javax.sql.DataSource" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" testOnBorrow="true" testOnReturn="false" testWhileIdle="true" validationQuery="SELECT 1" validationQueryTimeout="20000" validationInterval="30000" timeBetweenEvictionRunsMillis="60000" logValidationErrors="true" autoReconnect="true" username="webuser" password="xxxxxxx" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://databasename.us-east-1.rds.amazonaws.com:3306/test-db" maxActive="15" minIdle="2" maxIdle="10" maxWait="10000" maxAge="7200000"/> </Context> Now, as you can see, the database is running on Amazon RDS (where our live servers are), and thus is about 200ms round trip time away from my machine. I have already checked that I have security permissions to that database from my machine, (and anyway, it connects after 75 secs, so it cant be that). My initial thought was that Tomcat 7 and hibernate are doing something weird (like pre-instantiating a bunch of connections or something), and the latency to the database is amplifying the effects. While trying to diagnose the problem, I used jstack to get a stack trace of the Tomcat 7 server while its doing its startup thing. Here is the stack trace... Full thread dump Java HotSpot(TM) 64-Bit Server VM (20.12-b01-434 mixed mode): "Attach Listener" daemon prio=9 tid=7fa4c0038800 nid=0x10c39a000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Abandoned connection cleanup thread" daemon prio=5 tid=7fa4bb810000 nid=0x10f3ba000 in Object.wait() [10f3b9000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f40a0070> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <7f40a0070> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at com.mysql.jdbc.NonRegisteringDriver$1.run(NonRegisteringDriver.java:93) "PoolCleaner[545768040:1352724902327]" daemon prio=5 tid=7fa4be852800 nid=0x10e772000 in Object.wait() [10e771000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f40c7c90> (a java.util.TaskQueue) at java.util.TimerThread.mainLoop(Timer.java:509) - locked <7f40c7c90> (a java.util.TaskQueue) at java.util.TimerThread.run(Timer.java:462) "localhost-startStop-1" daemon prio=5 tid=7fa4bd034800 nid=0x10d66b000 runnable [10d668000] java.lang.Thread.State: RUNNABLE at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(SocketInputStream.java:129) at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114) at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161) at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189) - locked <7f3673be0> (a com.mysql.jdbc.util.ReadAheadInputStream) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3014) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3467) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3456) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3997) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2713) - locked <7f366a1c0> (a com.mysql.jdbc.JDBC4Connection) at com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1930) at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3571) at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2445) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215) - locked <7f366a1c0> (a com.mysql.jdbc.JDBC4Connection) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) at sun.reflect.GeneratedConstructorAccessor10.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:411) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334) at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:278) at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182) at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:699) at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:631) at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:485) at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) - locked <7f34f0dc8> (a org.apache.tomcat.jdbc.pool.DataSource) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:539) at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:237) at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:143) at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304) at org.apache.naming.NamingContext.lookup(NamingContext.java:843) at org.apache.naming.NamingContext.lookup(NamingContext.java:154) at org.apache.naming.NamingContext.lookup(NamingContext.java:831) at org.apache.naming.NamingContext.lookup(NamingContext.java:168) at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1061) at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:671) at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:270) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5173) - locked <7f46b07f0> (a org.apache.catalina.core.StandardContext) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f46b07f0> (a org.apache.catalina.core.StandardContext) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:680) "Catalina-startStop-1" daemon prio=5 tid=7fa4b7a5e800 nid=0x10d568000 waiting on condition [10d567000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <7f480e970> (a java.util.concurrent.FutureTask$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:218) at java.util.concurrent.FutureTask.get(FutureTask.java:83) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:680) "GC Daemon" daemon prio=2 tid=7fa4b9912800 nid=0x10d465000 in Object.wait() [10d464000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f4506d28> (a sun.misc.GC$LatencyLock) at sun.misc.GC$Daemon.run(GC.java:100) - locked <7f4506d28> (a sun.misc.GC$LatencyLock) "Low Memory Detector" daemon prio=5 tid=7fa4b480b800 nid=0x10c8ae000 runnable [00000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread1" daemon prio=9 tid=7fa4b480b000 nid=0x10c7ab000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread0" daemon prio=9 tid=7fa4b480a000 nid=0x10c6a8000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" daemon prio=9 tid=7fa4b4809800 nid=0x10c5a5000 runnable [00000000] java.lang.Thread.State: RUNNABLE "Surrogate Locker Thread (Concurrent GC)" daemon prio=5 tid=7fa4b4808800 nid=0x10c4a2000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Finalizer" daemon prio=8 tid=7fa4b793f000 nid=0x10c297000 in Object.wait() [10c296000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f451c8f0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <7f451c8f0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159) "Reference Handler" daemon prio=10 tid=7fa4b793e000 nid=0x10c194000 in Object.wait() [10c193000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f452e168> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:485) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116) - locked <7f452e168> (a java.lang.ref.Reference$Lock) "main" prio=5 tid=7fa4b7800800 nid=0x104329000 waiting on condition [104327000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <7f480e9a0> (a java.util.concurrent.FutureTask$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:218) at java.util.concurrent.FutureTask.get(FutureTask.java:83) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f453e810> (a org.apache.catalina.core.StandardService) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732) - locked <7f4506d58> (a [Lorg.apache.catalina.Service;) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f44f7ba0> (a org.apache.catalina.core.StandardServer) at org.apache.catalina.startup.Catalina.start(Catalina.java:684) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:451) "VM Thread" prio=9 tid=7fa4b7939800 nid=0x10c091000 runnable "Gang worker#0 (Parallel GC Threads)" prio=9 tid=7fa4b7802000 nid=0x10772b000 runnable "Gang worker#1 (Parallel GC Threads)" prio=9 tid=7fa4b7802800 nid=0x10782e000 runnable "Gang worker#2 (Parallel GC Threads)" prio=9 tid=7fa4b7803000 nid=0x107931000 runnable "Gang worker#3 (Parallel GC Threads)" prio=9 tid=7fa4b7804000 nid=0x107a34000 runnable "Gang worker#4 (Parallel GC Threads)" prio=9 tid=7fa4b7804800 nid=0x107b37000 runnable "Gang worker#5 (Parallel GC Threads)" prio=9 tid=7fa4b7805000 nid=0x107c3a000 runnable "Gang worker#6 (Parallel GC Threads)" prio=9 tid=7fa4b7805800 nid=0x107d3d000 runnable "Gang worker#7 (Parallel GC Threads)" prio=9 tid=7fa4b7806800 nid=0x107e40000 runnable "Concurrent Mark-Sweep GC Thread" prio=9 tid=7fa4b78e3800 nid=0x10bd0b000 runnable "Gang worker#0 (Parallel CMS Threads)" prio=9 tid=7fa4b78e2800 nid=0x10b305000 runnable "Gang worker#1 (Parallel CMS Threads)" prio=9 tid=7fa4b78e3000 nid=0x10b408000 runnable "VM Periodic Task Thread" prio=10 tid=7fa4b4815800 nid=0x10c9b1000 waiting on condition "Exception Catcher Thread" prio=10 tid=7fa4b7801800 nid=0x104554000 runnable JNI global references: 919 The only thing I can figure out from this is that it looks like the mysql jdbc drivers might have something to do with the long start up (the various stack traces I took during the start up process all pretty much look the same as this). Could anyone shed some light on what might be causing this? Have I done something dense in my context.xml? Is hibernate perhaps to blame?

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  • OIM 11g notification framework

    - by Rajesh G Kumar
    OIM 11g has introduced an improved and template based Notifications framework. New release has removed the limitation of sending text based emails (out-of-the-box emails) and enhanced to support html features. New release provides in-built out-of-the-box templates for events like 'Reset Password', 'Create User Self Service' , ‘User Deleted' etc. Also provides new APIs to support custom templates to send notifications out of OIM. OIM notification framework supports notification mechanism based on events, notification templates and template resolver. They are defined as follows: Ø Events are defined as XML file and imported as part of MDS database in order to make notification event available for use. Ø Notification templates are created using OIM advance administration console. The template contains the text and the substitution 'variables' which will be replaced with the data provided by the template resolver. Templates support internationalization and can be defined as HTML or in form of simple text. Ø Template resolver is a Java class that is responsible to provide attributes and data to be used at runtime and design time. It must be deployed following the OIM plug-in framework. Resolver data provided at design time is to be used by end user to design notification template with available entity variables and it also provides data at runtime to replace the designed variable with value to be displayed to recipients. Steps to define custom notifications in OIM 11g are: Steps# Steps 1. Define the Notification Event 2. Create the Custom Template Resolver class 3. Create Template with notification contents to be sent to recipients 4. Create Event triggering spots in OIM 1. Notification Event metadata The Notification Event is defined as XML file which need to be imported into MDS database. An event file must be compliant with the schema defined by the notification engine, which is NotificationEvent.xsd. The event file contains basic information about the event.XSD location in MDS database: “/metadata/iam-features-notification/NotificationEvent.xsd”Schema file can be viewed by exporting file from MDS using weblogicExportMetadata.sh script.Sample Notification event metadata definition: 1: <?xml version="1.0" encoding="UTF-8"?> 2: <Events xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:noNamespaceSchemaLocation="../../../metadata/NotificationEvent.xsd"> 3: <EventType name="Sample Notification"> 4: <StaticData> 5: <Attribute DataType="X2-Entity" EntityName="User" Name="Granted User"/> 6: </StaticData> 7: <Resolver class="com.iam.oim.demo.notification.DemoNotificationResolver"> 8: <Param DataType="91-Entity" EntityName="Resource" Name="ResourceInfo"/> 9: </Resolver> 10: </EventType> 11: </Events> Line# Description 1. XML file notation tag 2. Events is root tag 3. EventType tag is to declare a unique event name which will be available for template designing 4. The StaticData element lists a set of parameters which allow user to add parameters that are not data dependent. In other words, this element defines the static data to be displayed when notification is to be configured. An example of static data is the User entity, which is not dependent on any other data and has the same set of attributes for all event instances and notification templates. Available attributes are used to be defined as substitution tokens in the template. 5. Attribute tag is child tag for StaticData to declare the entity and its data type with unique reference name. User entity is most commonly used Entity as StaticData. 6. StaticData closing tag 7. Resolver tag defines the resolver class. The Resolver class must be defined for each notification. It defines what parameters are available in the notification creation screen and how those parameters are replaced when the notification is to be sent. Resolver class resolves the data dynamically at run time and displays the attributes in the UI. 8. The Param DataType element lists a set of parameters which allow user to add parameters that are data dependent. An example of the data dependent or a dynamic entity is a resource object which user can select at run time. A notification template is to be configured for the resource object. Corresponding to the resource object field, a lookup is displayed on the UI. When a user selects the event the call goes to the Resolver class provided to fetch the fields that are displayed in the Available Data list, from which user can select the attribute to be used on the template. Param tag is child tag to declare the entity and its data type with unique reference name. 9. Resolver closing tag 10 EventType closing tag 11. Events closing tag Note: - DataType needs to be declared as “X2-Entity” for User entity and “91-Entity” for Resource or Organization entities. The dynamic entities supported for lookup are user, resource, and organization. Once notification event metadata is defined, need to be imported into MDS database. Fully qualified resolver class name need to be define for XML but do not need to load the class in OIM yet (it can be loaded later). 2. Coding the notification resolver All event owners have to provide a resolver class which would resolve the data dynamically at run time. Custom resolver class must implement the interface oracle.iam.notification.impl.NotificationEventResolver and override the implemented methods with actual implementation. It has 2 methods: S# Methods Descriptions 1. public List<NotificationAttribute> getAvailableData(String eventType, Map<String, Object> params); This API will return the list of available data variables. These variables will be available on the UI while creating/modifying the Templates and would let user select the variables so that they can be embedded as a token as part of the Messages on the template. These tokens are replaced by the value passed by the resolver class at run time. Available data is displayed in a list. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the entity name and the corresponding value for which available data is to be fetched. Sample code snippet: List<NotificationAttribute> list = new ArrayList<NotificationAttribute>(); long objKey = (Long) params.get("resource"); //Form Field details based on Resource object key HashMap<String, Object> formFieldDetail = getObjectFormName(objKey); for (Iterator<?> itrd = formFieldDetail.entrySet().iterator(); itrd.hasNext(); ) { NotificationAttribute availableData = new NotificationAttribute(); Map.Entry formDetailEntrySet = (Entry<?, ?>)itrd.next(); String fieldLabel = (String)formDetailEntrySet.getValue(); availableData.setName(fieldLabel); list.add(availableData); } return list; 2. Public HashMap<String, Object> getReplacedData(String eventType, Map<String, Object> params); This API would return the resolved value of the variables present on the template at the runtime when notification is being sent. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the base values such as usr_key, obj_key etc required by the resolver implementation to resolve the rest of the variables in the template. Sample code snippet: HashMap<String, Object> resolvedData = new HashMap<String, Object>();String firstName = getUserFirstname(params.get("usr_key"));resolvedData.put("fname", firstName); String lastName = getUserLastName(params.get("usr_key"));resolvedData.put("lname", lastname);resolvedData.put("count", "1 million");return resolvedData; This code must be deployed as per OIM 11g plug-in framework. The XML file defining the plug-in is as below: <?xml version="1.0" encoding="UTF-8"?> <oimplugins xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <plugins pluginpoint="oracle.iam.notification.impl.NotificationEventResolver"> <plugin pluginclass= " com.iam.oim.demo.notification.DemoNotificationResolver" version="1.0" name="Sample Notification Resolver"/> </plugins> </oimplugins> 3. Defining the template To create a notification template: Log in to the Oracle Identity Administration Click the System Management tab and then click the Notification tab From the Actions list on the left pane, select Create On the Create page, enter values for the following fields under the Template Information section: Template Name: Demo template Description Text: Demo template Under the Event Details section, perform the following: From the Available Event list, select the event for which the notification template is to be created from a list of available events. Depending on your selection, other fields are displayed in the Event Details section. Note that the template Sample Notification Event created in the previous step being used as the notification event. The contents of the Available Data drop down are based on the event XML StaticData tag, the drop down basically lists all the attributes of the entities defined in that tag. Once you select an element in the drop down, it will show up in the Selected Data text field and then you can just copy it and paste it into either the message subject or the message body fields prefixing $ symbol. Example if list has attribute like First_Name then message body will contains this as $First_Name which resolver will parse and replace it with actual value at runtime. In the Resource field, select a resource from the lookup. This is the dynamic data defined by the Param DataType element in the XML definition. Based on selected resource getAvailableData method of resolver will be called to fetch the resource object attribute detail, if method is overridden with required implementation. For current scenario, Map<String, Object> params will get populated with object key as value and key as “resource” in the map. This is the only input will be provided to resolver at design time. You need to implement the further logic to fetch the object attributes detail to populate the available Data list. List string should not have space in between, if object attributes has space for attribute name then implement logic to replace the space with ‘_’ before populating the list. Example if attribute name is “First Name” then make it “First_Name” and populate the list. Space is not supported while you try to parse and replace the token at run time with real value. Make a note that the Available Data and Selected Data are used in the substitution tokens definition only, they do not define the final data that will be sent in the notification. OIM will invoke the resolver class to get the data and make the substitutions. Under the Locale Information section, enter values in the following fields: To specify a form of encoding, select either UTF-8 or ASCII. In the Message Subject field, enter a subject for the notification. From the Type options, select the data type in which you want to send the message. You can choose between HTML and Text/Plain. In the Short Message field, enter a gist of the message in very few words. In the Long Message field, enter the message that will be sent as the notification with Available data token which need to be replaced by resolver at runtime. After you have entered the required values in all the fields, click Save. A message is displayed confirming the creation of the notification template. Click OK 4. Triggering the event A notification event can be triggered from different places in OIM. The logic behind the triggering must be coded and plugged into OIM. Examples of triggering points for notifications: Event handlers: post process notifications for specific data updates in OIM users Process tasks: to notify the users that a provisioning task was executed by OIM Scheduled tasks: to notify something related to the task The scheduled job has two parameters: Template Name: defines the notification template to be sent User Login: defines the user record that will provide the data to be sent in the notification Sample Code Snippet: public void execute(String templateName , String userId) { try { NotificationService notService = Platform.getService(NotificationService.class); NotificationEvent eventToSend=this.createNotificationEvent(templateName,userId); notService.notify(eventToSend); } catch (Exception e) { e.printStackTrace(); } } private NotificationEvent createNotificationEvent(String poTemplateName, String poUserId) { NotificationEvent event = new NotificationEvent(); String[] receiverUserIds= { poUserId }; event.setUserIds(receiverUserIds); event.setTemplateName(poTemplateName); event.setSender(null); HashMap<String, Object> templateParams = new HashMap<String, Object>(); templateParams.put("USER_LOGIN",poUserId); event.setParams(templateParams); return event; } public HashMap getAttributes() { return null; } public void setAttributes() {} }

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  • Subterranean IL: The ThreadLocal type

    - by Simon Cooper
    I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

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  • Dynamic scoping in Clojure?

    - by j-g-faustus
    Hi, I'm looking for an idiomatic way to get dynamically scoped variables in Clojure (or a similar effect) for use in templates and such. Here is an example problem using a lookup table to translate tag attributes from some non-HTML format to HTML, where the table needs access to a set of variables supplied from elsewhere: (def *attr-table* ; Key: [attr-key tag-name] or [boolean-function] ; Value: [attr-key attr-value] (empty array to ignore) ; Context: Variables "tagname", "akey", "aval" '( ; translate :LINK attribute in <a> to :href [:LINK "a"] [:href aval] ; translate :LINK attribute in <img> to :src [:LINK "img"] [:src aval] ; throw exception if :LINK attribute in any other tag [:LINK] (throw (RuntimeException. (str "No match for " tagname))) ; ... more rules ; ignore string keys, used for internal bookkeeping [(string? akey)] [] )) ; ignore I want to be able to evaluate the rules (left hand side) as well as the result (right hand side), and need some way to put the variables in scope at the location where the table is evaluated. I also want to keep the lookup and evaluation logic independent of any particular table or set of variables. I suppose there are similar issues involved in templates (for example for dynamic HTML), where you don't want to rewrite the template processing logic every time someone puts a new variable in a template. Here is one approach using global variables and bindings. I have included some logic for the table lookup: ;; Generic code, works with any table on the same format. (defn rule-match? [rule-val test-val] "true if a single rule matches a single argument value" (cond (not (coll? rule-val)) (= rule-val test-val) ; plain value (list? rule-val) (eval rule-val) ; function call :else false )) (defn rule-lookup [test-val rule-table] "looks up rule match for test-val. Returns result or nil." (loop [rules (partition 2 rule-table)] (when-not (empty? rules) (let [[select result] (first rules)] (if (every? #(boolean %) (map rule-match? select test-val)) (eval result) ; evaluate and return result (recur (rest rules)) ))))) ;; Code specific to *attr-table* (def tagname) ; need these globals for the binding in html-attr (def akey) (def aval) (defn html-attr [tagname h-attr] "converts to html attributes" (apply hash-map (flatten (map (fn [[k v :as kv]] (binding [tagname tagname akey k aval v] (or (rule-lookup [k tagname] *attr-table*) kv))) h-attr )))) (defn test-attr [] "test conversion" (prn "a" (html-attr "a" {:LINK "www.google.com" "internal" 42 :title "A link" })) (prn "img" (html-attr "img" {:LINK "logo.png" }))) user=> (test-attr) "a" {:href "www.google.com", :title "A link"} "img" {:src "logo.png"} This is nice in that the lookup logic is independent of the table, so it can be reused with other tables and different variables. (Plus of course that the general table approach is about a quarter of the size of the code I had when I did the translations "by hand" in a giant cond.) It is not so nice in that I need to declare every variable as a global for the binding to work. Here is another approach using a "semi-macro", a function with a syntax-quoted return value, that doesn't need globals: (defn attr-table [tagname akey aval] `( [:LINK "a"] [:href ~aval] [:LINK "img"] [:src ~aval] [:LINK] (throw (RuntimeException. (str "No match for " tagname))) ; ... more rules [(string? ~akey)] [] ))) Only a couple of changes are needed to the rest of the code: In rule-match?, when syntax-quoted the function call is no longer a list: - (list? rule-val) (eval rule-val) + (seq? rule-val) (eval rule-val) In html-attr: - (binding [tagname tagname akey k aval v] - (or (rule-lookup [k tagname] *attr-table*) kv))) + (or (rule-lookup [k tagname] (attr-table tagname k v)) kv))) And we get the same result without globals. (And without dynamic scoping.) Are there other alternatives to pass along sets of variable bindings declared elsewhere, without the globals required by Clojure's binding? Is there an idiomatic way of doing it, like Ruby's binding or Javascript's function.apply(context)?

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