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• Pathfinding with MicroPather : costs calculations with sectors and portals

  - by Adan

  Hello, I'm considering using micropather to help me with pathfinding. I'm not using a discrete map : I'm working in 2d with sectors and portales. However, I'm just wondering what is the best way to compute costs with this library in this context. Just to be more clear about geometrical shapes I'm using : sectors are basically convex polygons, and portals are segments that lies on sector's edge. Micropather exposes a pure virtual Graph class that you must inherate and overrides 3 functions. I understand how pathfinding works, so there's no problem in overriding those functions. Right now, my implementation give me results, i.e I'm able to find a path in my map, but I'm not sure I'm using an optimal solution. For the AdjacentCost method : I just take the distance between sector's centers as the cost. I think a better solution should be to use the portal between the two sectors, compute its center, and then the cost should be : distance( sector A center, portal center ) + distance ( sector B center, portal center ). I'm pretty sure the approximation I'm using with just sector's center is enough for most cases, but maybe with thin and long sectors that are perpendicular, this approximation could mislead the A* algorithm. For the LeastCostEstimate method : I just take the midpoint of the two sectors. So, as you understand, I'm always working with sectors' centers, and it's working fine. And I'm pretty sure there's a better way to work. Any suggestions or feedbacks? Thanks in advance!

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• algorithm for Virtual Machine(VM) Consolidation in Cloud

  - by devansh dalal

  PROBLEM: We have N physical machines(PMs) each with ram Ri, cpu Ci and a set of currently scheduled VMs each with ram requirement ri and ci respectively Moving(Migrating) any VM from one PM to other has a cost associated which depends on its ram ri. A PM with no VMs is shut down to save power. Our target is to minimize the weighted sum of (N,migration cost) by migrating some VMs i.e. minimize the number of working PMs as well as not to degrade the service level due to excessive migrations. My Approach: Brute Force approach is choosing the minimum loaded PM and try to fit its VMs to other PMs by First Fit Decreasing algorithm or we can select the victim PMs and target PMs based on their loading level and shut down victims if possible by moving their VMs to targets. I tried this Greedy approach on the Data of Baadal(IIT-D cloud) but It isn't giving promising results. I have also tried to study the Ant colony optimization for dynamic VM consolidating but was unable to understand very much. I used the links. http://dumas.ccsd.cnrs.fr/docs/00/72/52/15/PDF/Esnault.pdf http://hal.archives-ouvertes.fr/docs/00/72/38/56/PDF/RR-8032.pdf Would anyone please explain the solution or suggest any new approach for better performance soon. Thanks in advance.

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• Robots &amp; Pencils Bring iOS Dev Camp/Dev School to Winnipeg

  - by D'Arcy Lussier

  My buddy Paul Thorsteinson from Robots and Pencils has come up with an elaborate way to collect his Mac power adaptor that I keep forgetting to mail to him – he’s coming to town with Jonathan Rasmusson to run an iPhone Dev Camp and two-day Dev School here in Winnipeg! From the email he sent me: We are going to be bringing our successful iOS dev school out to the 'Peg in October as well has hosting a dev camp on the Friday night (comparable to a .net user group type deal).  If you know any peeps in Manitoba who are interested in these, please pass along!  .Net developers are welcome to come and heckle as well ;) Winnipeg iPhone Dev Camp October 26th Marlborough Hotel, 5:30pm Cost: $10 http://ios-dev-camp-winnipeg-eorg.eventbrite.com/ ^for devs of any level interested in meeting other devs hearing talks of all levels.  Food and networking Winnipeg iPhone Dev School October 27th, 28th, Marlborough Hotel Cost: $899 + GST http://academy.robotsandpencils.com/training ^For devs looking to get their feet wet in iOS dev Paul has spoken at Prairie Dev Con before and is vastly knowledgeable in mobile development. You can see his work in Spy vs Spy, Catch the Princess, World Explorer for Minecraft, Deco Windshield (yes they run their entire business on their iPad), Anthm, Own This World and too many other apps. If you’re into iOS development, looking to get in, or wanting to improve your skills, consider these great professional development opportunities! D

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• WebCenter at Oracle Day Toronto

  - by Lance Shaw

  The Oracle Day event took place in Toronto yesterday at the Hyatt Regency Hotel downtown.  Attendance was excellent and it was standing room only at the keynote sessions.   Anytime the venue has to bring in chairs to handle the overflow crowd, you know there is a lot of interest! This year, WebCenter was featured prominently as part of the Fusion Middleware session track.  What was interesting to see was just how many customers are interested in consolidating and simplifying their existing infrastructure.  So many companies are still struggling with information silos such as file shares, SharePoint Sites and a myriad of departmental or process-centric repositories.  Naturally, these get more and more expensive to manage over time so there is a high level of interest in reducing the size, scope and cost of this infrastructure.  When companies see how they can use Fusion Middleware and related technologies to integrate with WebCenter Content, Imaging and other solutions to centralize content delivery across business applications, they quickly realize that there are significant cost savings to be had. Oracle Day Events are happening all over the world and there is likely going to be one near you.  To check out the full list and to register, visit the Event page here.  It is a great way to not only hear about WebCenter and how it can be used to your advantage, but also a great way to learn about the broader set of related products in the Fusion Middleware portfolio that are available to extend and enhance the power of your particular business solutions. If you cannot make it, or missed the event in your area, be sure to visit our new WebCenter Content page with a variety of informative assets all in one simple location.  It's a new page designed to provide you with easy access to customer stories, videos, whitepapers, webcasts and more.  We hope you find it valuable!

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• The Mac Tax

  - by Robert May

  One of our users was having difficulties with their mac and using some web software.  I decided to go peruse the landscape and see how much of a premium people were paying for their macs.  I priced out a Dell and a Mac from their websites.  I tried to get them as close to the same configuration, from a hardware standpoint, as I could.  I found the following: Apple Macbook Pro   Dell XPS 17 There are several important differences in the hardware: The mac doesn’t have a blueray player, but the dell does. The mac has a slightly slower processor. The mac claims to have a better battery, but doesn’t list the specifics, so there’s no way to tell. The mac doesn’t list the video card stats, so there’s no way to tell how comparable they are, but they’re probably close. The mac doesn’t come with any additional software.  No iWorks, iPhoto, etc.  They were left to their default of None, so arguably, the Dell is more functional out of the box. Other than changing the hardware specs to be close, all other configuration options were left at their default. So riddle me this, Batman:  Why do people buy Macs?  I have several dev buddies that own them, but I can’t justify the cost.  First, most of them load bootcamp and/or parallels at extra cost to run windows 7 and windows apps.  The hardware isn’t as good.  The price is almost twice as expensive. How do you justify the premium price? Technorati Tags: General

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• Is there really anything to gain with complex design? [duplicate]

  - by SB2055

  This question already has an answer here: What is enterprise software, exactly? 8 answers I've been working for a consulting firm for some time, with clients of various sizes, and I've seen web applications ranging in complexity from really simple: MVC Service Layer EF DB To really complex: MVC UoW DI / IoC Repository Service UI Tests Unit Tests Integration Tests But on both ends of the spectrum, the quality requirements are about the same. In simple projects, new devs / consultants can hop on, make changes, and contribute immediately, without having to wade through 6 layers of abstraction to understand what's going on, or risking misunderstanding some complex abstraction and costing down the line. In all cases, there was never a need to actually make code swappable or reusable - and the tests were never actually maintained past the first iteration because requirements changed, it was too time-consuming, deadlines, business pressure, etc etc. So if - in the end - testing and interfaces aren't used rapid development (read: cost-savings) is a priority the project's requirements will be changing a lot while in development ...would it be wrong to recommend a super-simple architecture, even to solve a complex problem, for an enterprise client? Is it complexity that defines enterprise solutions, or is it the reliability, # concurrent users, ease-of-maintenance, or all of the above? I know this is a very vague question, and any answer wouldn't apply to all cases, but I'm interested in hearing from devs / consultants that have been in the business for a while and that have worked with these varying degrees of complexity, to hear if the cool-but-expensive abstractions are worth the overall cost, at least while the project is in development.

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• How would i rank my keywords in Yahoo search engine?

  - by user1430715

  I am working as search engine optimizer team lead in a company and facing problem in a project which name is http://www.Prooftech.com.sg... Problem :- The Website has 10 keywords for which my client wanted the top 10 Ranking in Yahoo Singapore search engine. I have got top 10 ranking for the following 7 keywords Waterproofing, RC Roof ,Wall Leakages ,Ceiling Leakages , Water Leakages ,Roof Tile Coating ,Roof Tiles Repair in my 3 months work but still i am not getting the listing positions for Roof ,Concrete Repair ,Grouting .... I have Done lot of Bookmarking ,Blog Commenting ,Blog Creations ,Press Release,Classified Ads to get these 3 keywords in listing but there is no changes in the results.... Can any help me out from this problem so i can get Good rankings for Roof ,Concrete Repair ,Grouting

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• Joining on NULLs

  - by Dave Ballantyne

  A problem I see on a fairly regular basis is that of dealing with NULL values.  Specifically here, where we are joining two tables on two columns, one of which is ‘optional’ ie is nullable.  So something like this: i.e. Lookup where all the columns are equal, even when NULL.   NULL’s are a tricky thing to initially wrap your mind around.  Statements like “NULL is not equal to NULL and neither is it not not equal to NULL, it’s NULL” can cause a serious brain freeze and leave you a gibbering wreck and needing your mummy. Before we plod on, time to setup some data to demo against. Create table #SourceTable ( Id integer not null, SubId integer null, AnotherCol char(255) not null ) go create unique clustered index idxSourceTable on #SourceTable(id,subID) go with cteNums as ( select top(1000) number from master..spt_values where type ='P' ) insert into #SourceTable select Num1.number,nullif(Num2.number,0),'SomeJunk' from cteNums num1 cross join cteNums num2 go Create table #LookupTable ( Id integer not null, SubID integer null ) go insert into #LookupTable Select top(100) id,subid from #SourceTable where subid is not null order by newid() go insert into #LookupTable Select top(3) id,subid from #SourceTable where subid is null order by newid() If that has run correctly, you will have 1 million rows in #SourceTable and 103 rows in #LookupTable.  We now want to join one to the other. First attempt – Lets just join select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and #LookupTable.SubID = #SourceTable.SubID OK, that’s a fail.  We had 100 rows back,  we didn’t correctly account for the 3 rows that have null values.  Remember NULL <> NULL and the join clause specifies SUBID=SUBID, which for those rows is not true. Second attempt – Lets deal with those pesky NULLS select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and isnull(#LookupTable.SubID,0) = isnull(#SourceTable.SubID,0) OK, that’s the right result, well done and 99.9% of the time that is where its left. It is a relatively trivial CPU overhead to wrap ISNULL around both columns and compare that result, so no problems.  But, although that’s true, this a relational database we are using here, not a procedural language.  SQL is a declarative language, we are making a request to the engine to get the results we want.  How we ask for them can make a ton of difference. Lets look at the plan for our second attempt, specifically the clustered index seek on the #SourceTable   There are 2 predicates. The ‘seek predicate’ and ‘predicate’.  The ‘seek predicate’ describes how SQLServer has been able to use an Index.  Here, it has been able to navigate the index to resolve where ID=ID.  So far so good, but what about the ‘predicate’ (aka residual probe) ? This is a row-by-row operation.  For each row found in the index matching the Seek Predicate, the leaf level nodes have been scanned and tested using this logical condition.  In this example [Expr1007] is the result of the IsNull operation on #LookupTable and that is tested for equality with the IsNull operation on #SourceTable.  This residual probe is quite a high overhead, if we can express our statement slightly differently to take full advantage of the index and make the test part of the ‘Seek Predicate’. Third attempt – X is null and Y is null So, lets state the query in a slightly manner: select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and ( #LookupTable.SubID = #SourceTable.SubID or (#LookupTable.SubID is null and #SourceTable.SubId is null) ) So its slightly wordier and may not be as clear in its intent to the human reader, that is what comments are for, but the key point is that it is now clearer to the query optimizer what our intention is. Let look at the plan for that query, again specifically the index seek operation on #SourceTable No ‘predicate’, just a ‘Seek Predicate’ against the index to resolve both ID and SubID.  A subtle difference that can be easily overlooked.  But has it made a difference to the performance ? Well, yes , a perhaps surprisingly high one. Clever query optimizer well done. If you are using a scalar function on a column, you a pretty much guaranteeing that a residual probe will be used.  By re-wording the query you may well be able to avoid this and use the index completely to resolve lookups. In-terms of performance and scalability your system will be in a much better position if you can.

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• Problem with a* implementation in pygame

  - by piyush3dxyz

  Yesterday i decide to make RTS game in pygame(pygame is best).I figured out many components of RTS game like unit selecting,health,resources but only 1 thing i still not understand.. which is a* pathfinding in pygame... I also done little bit of research on wiki,articles and papers...but still cant figure out problem.... function A*(start,goal) closedset := the empty set // The set of nodes already evaluated. openset := {start} // The set of tentative nodes to be evaluated, initially containing the start node came_from := the empty map // The map of navigated nodes. g_score[start] := 0 // Cost from start along best known path. // Estimated total cost from start to goal through y. f_score[start] := g_score[start] + heuristic_cost_estimate(start, goal) while openset is not empty current := the node in openset having the lowest f_score[] value if current = goal return reconstruct_path(came_from, goal) remove current from openset add current to closedset for each neighbor in neighbor_nodes(current) if neighbor in closedset continue tentative_g_score := g_score[current] + dist_between(current,neighbor) if neighbor not in openset or tentative_g_score <= g_score[neighbor] came_from[neighbor] := current g_score[neighbor] := tentative_g_score f_score[neighbor] := g_score[neighbor] + heuristic_cost_estimate(neighbor, goal) if neighbor not in openset add neighbor to openset return failure here is the pseudocode for wiki a* implementation......

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• Costs/profit of/when starting an indie company

  - by Jack

  In short, I want to start a game company. I do not have much coding experience (just basic understanding and ability to write basic programs), any graphics design experience, any audio mixing experience, or whatever else technical. However, I do have a lot of ideas, great analytical skills and a very logical approach to life. I do not have any friends who are even remotely technical (or creative in regards to games for that matter). So now that we've cleared that up, my question is this: how much, minimally, would it cost me to start such a company? I know that a game could be developed in under half a year, which means it would have to operate for half a year prior, and that's assuming that the people working on the first project do their jobs good, don't leave game breaking bugs, a bunch of minor bugs, etc.. So how much would it cost me, and what would be the likely profit in half a year? I'm looking at minimal costs here, as to do it, I would have to sell my current apartment and buy a new, smaller one, pay taxes, and likely move to US/CA/UK to be closer to technologically advanced people (and be able to speak the language of course). EDIT: I'm looking at a small project for starters, not a huge AAA title.

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• How do you compare programming job offers from companies in different countries?

  - by Danny Tuppeny

  This isn't really a programmer-specific question, but I'm not sure of a more appropriate place, and I think the users of this site are best able to answer the question in the context of programmers. Relocating to the US seems fairly common in the programming industry. I live in the UK, and maybe one day, I might do it too. So, if that day comes - how would you go about comparing job offers? Benefits are fairly easy to compare, but given the differences in cost of living, how would you go about comparing salaries and the quality of living you'll have? In a country where the cost of living is lower, you might be able to accept a lower salary (based on exchange rate) and still have the same quality of living. But what can you do to ensure this? In some cases, you may even take a "pay rise" in terms of exchange rate, but end up far worse off. How can you compare job offers across different countries to get an idea of the salary you would need in order to not feel you've gone "backwards"?

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• PeopleSoft CRM 9.2 Release Value Proposition

  - by Race Bannon

  Oracle's PeopleSoft Customer Relationship Management (CRM) delivers solutions that have been tailored to fit your industry business processes, your customer strategies, and your success criteria. With PeopleSoft CRM 9.2, organizations will be able to deploy a solution that delivers built-in best practices specific to your industry with a highly configurable, tightly integrated platform, ensuring that solutions will be fast to implement. The result is less configuration, less customization, and less integration. PeopleSoft Customer Relationship Management (CRM) is a world-class solution for organizations of every size and Oracle’s planned product roadmap for PeopleSoft applications is to deliver valuable, needed features for all of an organization’s constituents along three design principles — Simplicity, Productivity, and Lowered Total Cost of Ownership — as well as new application functionality as prioritized by our customers. The upcoming 9.2 release of PeopleSoft Customer Relationship Management focuses on these themes of Simplicity, Productivity, and Lower Total Cost of Ownership while also delivering robust new functionality to help your organization succeed. The recently published PeopleSoft CRM 9.2 Release Value Proposition provides overviews of the new features and enhancements planned for these applications for Release 9.2. This document offers customers a road map intended to help them assess the business benefits of upgrading to the 9.2 release while also helping them plan their IT projects and investments. (Link is to a My Oracle Support page, available to customers and partners.) Oracle continues to deliver enterprise-wide features that enhance our customer ownership experience and helps them run their businesses more efficiently and profitably. With the CRM 9.2 release, we continue to abide by this firm commitment we’ve made to our customers.

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• 724% Return on an SFA project with Oracle Sales Cloud and Marketing Cloud combined!

  - by Richard Lefebvre

  Oracle Sales Cloud and Marketing Cloud customer Apex IT gained just that?a 724% return on investment (ROI) when it implemented these Oracle Cloud solutions in its fast-moving, rapidly-growing business. Apex IT was just announced as a winner of the Nucleus Research 11th annual Technology ROI Awards. The award, given by the analyst firm, highlights organizations that have successfully leveraged IT deployments to maximize value per dollar spent. Fast Facts: Return on Investment – 724% Payback – 2 months Average annual benefit – $91,534 Cost : Benefit Ratio – 1:48 Business Benefits In addition to the ROI and cost metrics the award calls out improvements in Apex IT’s business operations—across both Sales and Marketing teams: Improved ability to identify new opportunities and focus sales resources on higher-probability deals Reduced administration and manual lead tracking—resulting in more time selling and a net new client increase of 46% Increased campaign productivity for both Marketing and Sales, including Oracle Marketing Cloud’s automation of campaign tracking and nurture programs Improved margins with more structured and disciplined sales processes—resulting in more effective deal negotiations Read the full Apex IT ROI Case Study. You also can learn more about Apex IT’s business, including the company’s work with Oracle Sales and Marketing Cloud on behalf of its clients. You can point your prospects and customers to the CX blog for a similar recap of the Apex IT award and a link to the Case Study.

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• Web dev/programmer with 4.5 yrs experience. Better for career: self-study or master's degree? [closed]

  - by Anonymous Programmer

  I'm a 28 year-old web developer/programmer with 4.5 years of experience, and I'm looking to jump-start my career. I'm trying to decide between self-study and a 1-year master's program in CS at a top school. I'm currently making 65K in a high cost-of-living area that is NOT a hot spot for technology firms. I code almost exclusively in Ruby/Rails, PHP/CodeIgniter, SQL, and JavaScript. I've slowly gained proficiency with Git. Roughly half the time I am architecting/coding, and half the time I am pounding out HTML/CSS for static brochureware sites. I'd like to make more more money while doing more challenging/interesting work, but I don't know where to start. I have an excellent academic record (math major with many CS credits, 3.9+ GPA), GRE scores, and recommendations, so I am confident that I could be admitted to a great CS master's program. On the other hand, there is the tuition and opportunity cost to consider. I feel like there are a number of practical languages/tools/skills worth knowing that I could teach myself - shell scripting, .NET, Python, Node.js, MongoDB, natural language processing techniques, etc. That said, it's one thing to read about a subject and another thing to have experience with it, which structured coursework provides. So, on to the concrete questions: What programming skills/knowledge should I develop to increase my earning potential and make me competitive for more interesting jobs? Will a master's degree in CS from a top school help me develop the above skills/knowledge, and if so, is it preferable to self-study (possibly for other reasons, e.g., the degree's value as a credential)?

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• Location Change Salary Differences [closed]

  - by GameDev

  DISCLAIMER: I know that this might be a "regional" question but I'm also asking for help as far as what resources to use to determine my decision. I'm currently talking to a recruiter for a game developer in the SF Bay area. I work in a relatively low-cost area in the south. I really want to get into game development but my current career is general web development. I'm very interested in taking the job, but my concern is that the amount they're willing to pay might be a relative pay cut. Here are some factors: It's not an entry-level position, the title is Senior Software Engineer. I have 5+ years of experience. The calculators online tell me that I should be expecting around 2x my current pay rate(http://www.bestplaces.net/col/). My current pay is in the mid $60k/yr, so that's like 120-130k. The recruiter told me at my experience level I can expect about $90-100/yr, and that those cost of living calculators were way off. The benefits will definitely be better, it's much larger company (help with commuting, catered meals, etc). But is the recruiter trying to give me a snow job on the pay scale, or is that a reasonable change from a smallish town in the south to somewhere in the SF bay area? How can I find this out? Glassdoor and Payscale seem to say "senior software developers" in that area make around 110 in median salary, but Payscale says it's closer to $135k, that range seems pretty large.

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• Efficient algorithm for Virtual Machine(VM) Consolidation in Cloud

  - by devansh dalal

  PROBLEM: We have N physical machines(PMs) each with ram Ri, cpu Ci and a set of currently scheduled VMs each with ram requirement ri and ci respectively Moving(Migrating) any VM from one PM to other has a cost associated which depends on its ram ri. A PM with no VMs is shut down to save power. Our target is to minimize the weighted sum of (N,migration cost) by migrating some VMs i.e. minimize the number of working PMs as well as not to degrade the service level due to excessive migrations. My Approach: Brute Force approach is choosing the minimum loaded PM and try to fit its VMs to other PMs by First Fit Decreasing algorithm or we can select the victim PMs and target PMs based on their loading level and shut down victims if possible by moving their VMs to targets. I tried this Greedy approach on the Data of Baadal(IIT-D cloud) but It isn't giving promising results. I have also tried to study the Ant colony optimization for dynamic VM consolidating but was unable to understand very much. I used the links. http://dumas.ccsd.cnrs.fr/docs/00/72/52/15/PDF/Esnault.pdf http://hal.archives-ouvertes.fr/docs/00/72/38/56/PDF/RR-8032.pdf Would anyone please clarify the solution or suggest any new approach/resources for better performance. I am basically searching for the algorithms not the physical optimizations and I also know that many commercial organizations have provided these solution but I just wanted to know more the underlying algorithms. Thanks in advance.

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• New "How do I ..." series

  - by Maria Colgan

  Over the last year or so the Optimizer development team has presented at a number of conferences and we got a lot of questions that start with "How do I ...". Where people were looking for a specific command or set of steps to fix a problem they had encountered. So we thought it would be a good idea to create a series of small posts that deal with these "How do I" question directly. We will use a simple example each time, that shows exactly what commands and procedures should be used to address a given problem. If you have an interesting "How do I .." question you would like to see us answer on the blog please email me and we will do our best to answer them! Watch out for the first post in this series which addresses the problem of "How do I deal with a third party application that has embedded hints that result in a sub-optimal execution plan in my environment?"

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• How "commercially savvy" should software developers be? [closed]

  - by mattnz

  I have been watching answers to many questions on this site, and have come to the conclusion that commercial pragmatism does not factor into many software development discussions. As a result, I seriously wonder at the commercial skills within the industry, specifically the ability to deliver projects on time and to a budget. I see no indication from the site that commercially successful project delivery is a serious concern, yet the industry has a reputation for poor performance in this. Rarely, if ever, does the cost of time factor into discussions. I have never seen concepts such as opportunity cost, time to market, competitive advantage or cash flow mentioned, let alone discussed in technical answers to questions. How can you answer virtually any question without understanding the commercial background on which it is asked? Even Open source projects have a need to operate efficiently and deploy their limited resources to providing the most value for effort. Typically small start-ups have cash flow issues that outweigh longevity concerns, yet they are typically still advised to build for a future they probably won’t have if they do. Is it fair to say that these problems are solely the Managers and Project managers to solve, or are we, as developers, also responsible for ensuring successful on time, within budget delivery of projects, even if those budgets do not allow use to achieve engineering excellence?

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• Web optimization

  - by hmloo

  1. CSS Optimization Organize your CSS code Good CSS organization helps with future maintainability of the site, it helps you and your team member understand the CSS more quickly and jump to specific styles. Structure CSS code For small project, you can break your CSS code in separate blocks according to the structure of the page or page content. for example you can break your CSS document according the content of your web page(e.g. Header, Main Content, Footer) Structure CSS file For large project, you may feel having too much CSS code in one place, so it's the best to structure your CSS into more CSS files, and use a master style sheet to import these style sheets. this solution can not only organize style structure, but also reduce server request./*--------------Master style sheet--------------*/ @import "Reset.css"; @import "Structure.css"; @import "Typography.css"; @import "Forms.css"; Create index for your CSS Another important thing is to create index at the beginning of your CSS file, index can help you quickly understand the whole CSS structure./*---------------------------------------- 1. Header 2. Navigation 3. Main Content 4. Sidebar 5. Footer ------------------------------------------*/ Writing efficient CSS selectors keep in mind that browsers match CSS selectors from right to left and the order of efficiency for selectors 1. id (#myid) 2. class (.myclass) 3. tag (div, h1, p) 4. adjacent sibling (h1 + p) 5. child (ul > li) 6. descendent (li a) 7. universal (*) 8. attribute (a[rel="external"]) 9. pseudo-class and pseudo element (a:hover, li:first) the rightmost selector is called "key selector", so when you write your CSS code, you should choose more efficient key selector. Here are some best practice: Don't tag-qualify Never do this:div#myid div.myclass .myclass#myid IDs are unique, classes are more unique than a tag so they don't need a tag. Doing so makes the selector less efficient. Avoid overqualifying selectors for example#nav a is more efficient thanul#nav li a Don't repeat declarationExample: body {font-size:12px;}h1 {font-size:12px;font-weight:bold;} since h1 is already inherited from body, so you don't need to repeate atrribute. Using 0 instead of 0px Always using #selector { margin: 0; } There’s no need to include the px after 0, removing all those superfluous px can reduce the size of your CSS file. Group declaration Example: h1 { font-size: 16pt; } h1 { color: #fff; } h1 { font-family: Arial, sans-serif; } it’s much better to combine them:h1 { font-size: 16pt; color: #fff; font-family: Arial, sans-serif; } Group selectorsExample: h1 { color: #fff; font-family: Arial, sans-serif; } h2 { color: #fff; font-family: Arial, sans-serif; } it would be much better if setup as:h1, h2 { color: #fff; font-family: Arial, sans-serif; } Group attributeExample: h1 { color: #fff; font-family: Arial, sans-serif; } h2 { color: #fff; font-family: Arial, sans-serif; font-size: 16pt; } you can set different rules for specific elements after setting a rule for a grouph1, h2 { color: #fff; font-family: Arial, sans-serif; } h2 { font-size: 16pt; } Using Shorthand PropertiesExample: #selector { margin-top: 8px; margin-right: 4px; margin-bottom: 8px; margin-left: 4px; }Better: #selector { margin: 8px 4px 8px 4px; }Best: #selector { margin: 8px 4px; } a good diagram illustrated how shorthand declarations are interpreted depending on how many values are specified for margin and padding property. instead of using:#selector { background-image: url(”logo.png”); background-position: top left; background-repeat: no-repeat; } is used:#selector { background: url(logo.png) no-repeat top left; } 2. Image Optimization Image Optimizer Image Optimizer is a free Visual Studio2010 extension that optimizes PNG, GIF and JPG file sizes without quality loss. It uses SmushIt and PunyPNG for the optimization. Just right click on any folder or images in Solution Explorer and choose optimize images, then it will automatically optimize all PNG, GIF and JPEG files in that folder. CSS Image Sprites CSS Image Sprites are a way to combine a collection of images to a single image, then use CSS background-position property to shift the visible area to show the required image, many images can take a long time to load and generates multiple server requests, so Image Sprite can reduce the number of server requests and improve site performance. You can use many online tools to generate your image sprite and CSS, and you can also try the Sprite and Image Optimization framework released by The ASP.NET team.

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• What's is the point of PImpl pattern while we can use interface for same purpose in C++?

  - by ZijingWu

  I see a lot of source code which using PIMPL idiom in C++. I assume Its purposes are hidden the private data/type/implementation, so it can resolve dependence, and then reduce compile time and header include issue. But interface class in C++ also have this capability, it can also used to hidden data/type and implementation. And to hidden let the caller just see the interface when create object, we can add an factory method in it declaration in interface header. The comparison is: Cost: The interface way cost is lower, because you doesn't even need to repeat the public wrapper function implementation void Bar::doWork() { return m_impl->doWork(); }, you just need to define the signature in the interface. Well understand: The interface technology is more well understand by every C++ developer. Performance: Interface way performance not worse than PIMPL idiom, both an extra memory access. I assume the performance is same. Following is the pseudocode code to illustrate my question: // Forward declaration can help you avoid include BarImpl header, and those included in BarImpl header. class BarImpl; class Bar { public: // public functions void doWork(); private: // You doesn't need to compile Bar.cpp after change the implementation in BarImpl.cpp BarImpl* m_impl; }; The same purpose can be implement using interface: // Bar.h class IBar { public: virtual ~IBar(){} // public functions virtual void doWork() = 0; }; // to only expose the interface instead of class name to caller IBar* createObject(); So what's the point of PIMPL?

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• Differences Between NHibernate and Entity Framework

  - by Ricardo Peres

  Introduction NHibernate and Entity Framework are two of the most popular O/RM frameworks on the .NET world. Although they share some functionality, there are some aspects on which they are quite different. This post will describe this differences and will hopefully help you get started with the one you know less. Mind you, this is a personal selection of features to compare, it is by no way an exhaustive list. History First, a bit of history. NHibernate is an open-source project that was first ported from Java’s venerable Hibernate framework, one of the first O/RM frameworks, but nowadays it is not tied to it, for example, it has .NET specific features, and has evolved in different ways from those of its Java counterpart. Current version is 3.3, with 3.4 on the horizon. It currently targets .NET 3.5, but can be used as well in .NET 4, it only makes no use of any of its specific functionality. You can find its home page at NHForge. Entity Framework 1 came out with .NET 3.5 and is now on its second major version, despite being version 4. Code First sits on top of it and but came separately and will also continue to be released out of line with major .NET distributions. It is currently on version 4.3.1 and version 5 will be released together with .NET Framework 4.5. All versions will target the current version of .NET, at the time of their release. Its home location is located at MSDN. Architecture In NHibernate, there is a separation between the Unit of Work and the configuration and model instances. You start off by creating a Configuration object, where you specify all global NHibernate settings such as the database and dialect to use, the batch sizes, the mappings, etc, then you build an ISessionFactory from it. The ISessionFactory holds model and metadata that is tied to a particular database and to the settings that came from the Configuration object, and, there will typically be only one instance of each in a process. Finally, you create instances of ISession from the ISessionFactory, which is the NHibernate representation of the Unit of Work and Identity Map. This is a lightweight object, it basically opens and closes a database connection as required and keeps track of the entities associated with it. ISession objects are cheap to create and dispose, because all of the model complexity is stored in the ISessionFactory and Configuration objects. As for Entity Framework, the ObjectContext/DbContext holds the configuration, model and acts as the Unit of Work, holding references to all of the known entity instances. This class is therefore not lightweight as its NHibernate counterpart and it is not uncommon to see examples where an instance is cached on a field. Mappings Both NHibernate and Entity Framework (Code First) support the use of POCOs to represent entities, no base classes are required (or even possible, in the case of NHibernate). As for mapping to and from the database, NHibernate supports three types of mappings: XML-based, which have the advantage of not tying the entity classes to a particular O/RM; the XML files can be deployed as files on the file system or as embedded resources in an assembly; Attribute-based, for keeping both the entities and database details on the same place at the expense of polluting the entity classes with NHibernate-specific attributes; Strongly-typed code-based, which allows dynamic creation of the model and strongly typing it, so that if, for example, a property name changes, the mapping will also be updated. Entity Framework can use: Attribute-based (although attributes cannot express all of the available possibilities – for example, cascading); Strongly-typed code mappings. Database Support With NHibernate you can use mostly any database you want, including: SQL Server; SQL Server Compact; SQL Server Azure; Oracle; DB2; PostgreSQL; MySQL; Sybase Adaptive Server/SQL Anywhere; Firebird; SQLLite; Informix; Any through OLE DB; Any through ODBC. Out of the box, Entity Framework only supports SQL Server, but a number of providers exist, both free and commercial, for some of the most used databases, such as Oracle and MySQL. See a list here. Inheritance Strategies Both NHibernate and Entity Framework support the three canonical inheritance strategies: Table Per Type Hierarchy (Single Table Inheritance), Table Per Type (Class Table Inheritance) and Table Per Concrete Type (Concrete Table Inheritance). Associations Regarding associations, both support one to one, one to many and many to many. However, NHibernate offers far more collection types: Bags of entities or values: unordered, possibly with duplicates; Lists of entities or values: ordered, indexed by a number column; Maps of entities or values: indexed by either an entity or any value; Sets of entities or values: unordered, no duplicates; Arrays of entities or values: indexed, immutable. Querying NHibernate exposes several querying APIs: LINQ is probably the most used nowadays, and really does not need to be introduced; Hibernate Query Language (HQL) is a database-agnostic, object-oriented SQL-alike language that exists since NHibernate’s creation and still offers the most advanced querying possibilities; well suited for dynamic queries, even if using string concatenation; Criteria API is an implementation of the Query Object pattern where you create a semi-abstract conceptual representation of the query you wish to execute by means of a class model; also a good choice for dynamic querying; Query Over offers a similar API to Criteria, but using strongly-typed LINQ expressions instead of strings; for this, although more refactor-friendlier that Criteria, it is also less suited for dynamic queries; SQL, including stored procedures, can also be used; Integration with Lucene.NET indexer is available. As for Entity Framework: LINQ to Entities is fully supported, and its implementation is considered very complete; it is the API of choice for most developers; Entity-SQL, HQL’s counterpart, is also an object-oriented, database-independent querying language that can be used for dynamic queries; SQL, of course, is also supported. Caching Both NHibernate and Entity Framework, of course, feature first-level cache. NHibernate also supports a second-level cache, that can be used among multiple ISessionFactorys, even in different processes/machines: Hashtable (in-memory); SysCache (uses ASP.NET as the cache provider); SysCache2 (same as above but with support for SQL Server SQL Dependencies); Prevalence; SharedCache; Memcached; Redis; NCache; Appfabric Caching. Out of the box, Entity Framework does not have any second-level cache mechanism, however, there are some public samples that show how we can add this. ID Generators NHibernate supports different ID generation strategies, coming from the database and otherwise: Identity (for SQL Server, MySQL, and databases who support identity columns); Sequence (for Oracle, PostgreSQL, and others who support sequences); Trigger-based; HiLo; Sequence HiLo (for databases that support sequences); Several GUID flavors, both in GUID as well as in string format; Increment (for single-user uses); Assigned (must know what you’re doing); Sequence-style (either uses an actual sequence or a single-column table); Table of ids; Pooled (similar to HiLo but stores high values in a table); Native (uses whatever mechanism the current database supports, identity or sequence). Entity Framework only supports: Identity generation; GUIDs; Assigned values. Properties NHibernate supports properties of entity types (one to one or many to one), collections (one to many or many to many) as well as scalars and enumerations. It offers a mechanism for having complex property types generated from the database, which even include support for querying. It also supports properties originated from SQL formulas. Entity Framework only supports scalars, entity types and collections. Enumerations support will come in the next version. Events and Interception NHibernate has a very rich event model, that exposes more than 20 events, either for synchronous pre-execution or asynchronous post-execution, including: Pre/Post-Load; Pre/Post-Delete; Pre/Post-Insert; Pre/Post-Update; Pre/Post-Flush. It also features interception of class instancing and SQL generation. As for Entity Framework, only two events exist: ObjectMaterialized (after loading an entity from the database); SavingChanges (before saving changes, which include deleting, inserting and updating). Tracking Changes For NHibernate as well as Entity Framework, all changes are tracked by their respective Unit of Work implementation. Entities can be attached and detached to it, Entity Framework does, however, also support self-tracking entities. Optimistic Concurrency Control NHibernate supports all of the imaginable scenarios: SQL Server’s ROWVERSION; Oracle’s ORA_ROWSCN; A column containing date and time; A column containing a version number; All/dirty columns comparison. Entity Framework is more focused on Entity Framework, so it only supports: SQL Server’s ROWVERSION; Comparing all/some columns. Batching NHibernate has full support for insertion batching, but only if the ID generator in use is not database-based (for example, it cannot be used with Identity), whereas Entity Framework has no batching at all. Cascading Both support cascading for collections and associations: when an entity is deleted, their conceptual children are also deleted. NHibernate also offers the possibility to set the foreign key column on children to NULL instead of removing them. Flushing Changes NHibernate’s ISession has a FlushMode property that can have the following values: Auto: changes are sent to the database when necessary, for example, if there are dirty instances of an entity type, and a query is performed against this entity type, or if the ISession is being disposed; Commit: changes are sent when committing the current transaction; Never: changes are only sent when explicitly calling Flush(). As for Entity Framework, changes have to be explicitly sent through a call to AcceptAllChanges()/SaveChanges(). Lazy Loading NHibernate supports lazy loading for Associated entities (one to one, many to one); Collections (one to many, many to many); Scalar properties (thing of BLOBs or CLOBs). Entity Framework only supports lazy loading for: Associated entities; Collections. Generating and Updating the Database Both NHibernate and Entity Framework Code First (with the Migrations API) allow creating the database model from the mapping and updating it if the mapping changes. Extensibility As you can guess, NHibernate is far more extensible than Entity Framework. Basically, everything can be extended, from ID generation, to LINQ to SQL transformation, HQL native SQL support, custom column types, custom association collections, SQL generation, supported databases, etc. With Entity Framework your options are more limited, at least, because practically no information exists as to what can be extended/changed. It features a provider model that can be extended to support any database. Integration With Other Microsoft APIs and Tools When it comes to integration with Microsoft technologies, it will come as no surprise that Entity Framework offers the best support. For example, the following technologies are fully supported: ASP.NET (through the EntityDataSource); ASP.NET Dynamic Data; WCF Data Services; WCF RIA Services; Visual Studio (through the integrated designer). Documentation This is another point where Entity Framework is superior: NHibernate lacks, for starters, an up to date API reference synchronized with its current version. It does have a community mailing list, blogs and wikis, although not much used. Entity Framework has a number of resources on MSDN and, of course, several forums and discussion groups exist. Conclusion Like I said, this is a personal list. I may come as a surprise to some that Entity Framework is so behind NHibernate in so many aspects, but it is true that NHibernate is much older and, due to its open-source nature, is not tied to product-specific timeframes and can thus evolve much more rapidly. I do like both, and I chose whichever is best for the job I have at hands. I am looking forward to the changes in EF5 which will add significant value to an already interesting product. So, what do you think? Did I forget anything important or is there anything else worth talking about? Looking forward for your comments!

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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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• Windows Azure: Import/Export Hard Drives, VM ACLs, Web Sockets, Remote Debugging, Continuous Delivery, New Relic, Billing Alerts and More

  - by ScottGu

  Two weeks ago we released a giant set of improvements to Windows Azure, as well as a significant update of the Windows Azure SDK. This morning we released another massive set of enhancements to Windows Azure.  Today’s new capabilities include: Storage: Import/Export Hard Disk Drives to your Storage Accounts HDInsight: General Availability of our Hadoop Service in the cloud Virtual Machines: New VM Gallery, ACL support for VIPs Web Sites: WebSocket and Remote Debugging Support Notification Hubs: Segmented customer push notification support with tag expressions TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services Developer Analytics: New Relic support for Web Sites + Mobile Services Service Bus: Support for partitioned queues and topics Billing: New Billing Alert Service that sends emails notifications when your bill hits a threshold you define All of these improvements are now available to use immediately (note that some features are still in preview).  Below are more details about them. Storage: Import/Export Hard Disk Drives to Windows Azure I am excited to announce the preview of our new Windows Azure Import/Export Service! The Windows Azure Import/Export Service enables you to move large amounts of on-premises data into and out of your Windows Azure Storage accounts. It does this by enabling you to securely ship hard disk drives directly to our Windows Azure data centers. Once we receive the drives we’ll automatically transfer the data to or from your Windows Azure Storage account.  This enables you to import or export massive amounts of data more quickly and cost effectively (and not be constrained by available network bandwidth). Encrypted Transport Our Import/Export service provides built-in support for BitLocker disk encryption – which enables you to securely encrypt data on the hard drives before you send it, and not have to worry about it being compromised even if the disk is lost/stolen in transit (since the content on the transported hard drives is completely encrypted and you are the only one who has the key to it).  The drive preparation tool we are shipping today makes setting up bitlocker encryption on these hard drives easy. How to Import/Export your first Hard Drive of Data You can read our Getting Started Guide to learn more about how to begin using the import/export service.  You can create import and export jobs via the Windows Azure Management Portal as well as programmatically using our Server Management APIs. It is really easy to create a new import or export job using the Windows Azure Management Portal.  Simply navigate to a Windows Azure storage account, and then click the new Import/Export tab now available within it (note: if you don’t have this tab make sure to sign-up for the Import/Export preview): Then click the “Create Import Job” or “Create Export Job” commands at the bottom of it.  This will launch a wizard that easily walks you through the steps required: For more comprehensive information about Import/Export, refer to Windows Azure Storage team blog.  You can also send questions and comments to the [email protected] email address. We think you’ll find this new service makes it much easier to move data into and out of Windows Azure, and it will dramatically cut down the network bandwidth required when working on large data migration projects.  We hope you like it. HDInsight: 100% Compatible Hadoop Service in the Cloud Last week we announced the general availability release of Windows Azure HDInsight. HDInsight is a 100% compatible Hadoop service that allows you to easily provision and manage Hadoop clusters for big data processing in Windows Azure.  This release is now live in production, backed by an enterprise SLA, supported 24x7 by Microsoft Support, and is ready to use for production scenarios. HDInsight allows you to use Apache Hadoop tools, such as Pig and Hive, to process large amounts of data in Windows Azure Blob Storage. Because data is stored in Windows Azure Blob Storage, you can choose to dynamically create Hadoop clusters only when you need them, and then shut them down when they are no longer required (since you pay only for the time the Hadoop cluster instances are running this provides a super cost effective way to use them).  You can create Hadoop clusters using either the Windows Azure Management Portal (see below) or using our PowerShell and Cross Platform Command line tools: The import/export hard drive support that came out today is a perfect companion service to use with HDInsight – the combination allows you to easily ingest, process and optionally export a limitless amount of data.  We’ve also integrated HDInsight with our Business Intelligence tools, so users can leverage familiar tools like Excel in order to analyze the output of jobs.  You can find out more about how to get started with HDInsight here. Virtual Machines: VM Gallery Enhancements Today’s update of Windows Azure brings with it a new Virtual Machine gallery that you can use to create new VMs in the cloud.  You can launch the gallery by doing New->Compute->Virtual Machine->From Gallery within the Windows Azure Management Portal: The new Virtual Machine Gallery includes some nice enhancements that make it even easier to use: Search: You can now easily search and filter images using the search box in the top-right of the dialog.  For example, simply type “SQL” and we’ll filter to show those images in the gallery that contain that substring. Category Tree-view: Each month we add more built-in VM images to the gallery.  You can continue to browse these using the “All” view within the VM Gallery – or now quickly filter them using the category tree-view on the left-hand side of the dialog.  For example, by selecting “Oracle” in the tree-view you can now quickly filter to see the official Oracle supplied images. MSDN and Supported checkboxes: With today’s update we are also introducing filters that makes it easy to filter out types of images that you may not be interested in. The first checkbox is MSDN: using this filter you can exclude any image that is not part of the Windows Azure benefits for MSDN subscribers (which have highly discounted pricing - you can learn more about the MSDN pricing here). The second checkbox is Supported: this filter will exclude any image that contains prerelease software, so you can feel confident that the software you choose to deploy is fully supported by Windows Azure and our partners. Sort options: We sort gallery images by what we think customers are most interested in, but sometimes you might want to sort using different views. So we’re providing some additional sort options, like “Newest,” to customize the image list for what suits you best. Pricing information: We now provide additional pricing information about images and options on how to cost effectively run them directly within the VM Gallery. The above improvements make it even easier to use the VM Gallery and quickly create launch and run Virtual Machines in the cloud. Virtual Machines: ACL Support for VIPs A few months ago we exposed the ability to configure Access Control Lists (ACLs) for Virtual Machines using Windows PowerShell cmdlets and our Service Management API. With today’s release, you can now configure VM ACLs using the Windows Azure Management Portal as well. You can now do this by clicking the new Manage ACL command in the Endpoints tab of a virtual machine instance: This will enable you to configure an ordered list of permit and deny rules to scope the traffic that can access your VM’s network endpoints. For example, if you were on a virtual network, you could limit RDP access to a Windows Azure virtual machine to only a few computers attached to your enterprise. Or if you weren’t on a virtual network you could alternatively limit traffic from public IPs that can access your workloads: Here is the default behaviors for ACLs in Windows Azure: By default (i.e. no rules specified), all traffic is permitted. When using only Permit rules, all other traffic is denied. When using only Deny rules, all other traffic is permitted. When there is a combination of Permit and Deny rules, all other traffic is denied. Lastly, remember that configuring endpoints does not automatically configure them within the VM if it also has firewall rules enabled at the OS level.  So if you create an endpoint using the Windows Azure Management Portal, Windows PowerShell, or REST API, be sure to also configure your guest VM firewall appropriately as well. Web Sites: Web Sockets Support With today’s release you can now use Web Sockets with Windows Azure Web Sites.  This feature enables you to easily integrate real-time communication scenarios within your web based applications, and is available at no extra charge (it even works with the free tier).  Higher level programming libraries like SignalR and socket.io are also now supported with it. You can enable Web Sockets support on a web site by navigating to the Configure tab of a Web Site, and by toggling Web Sockets support to “on”: Once Web Sockets is enabled you can start to integrate some really cool scenarios into your web applications.  Check out the new SignalR documentation hub on www.asp.net to learn more about some of the awesome scenarios you can do with it. Web Sites: Remote Debugging Support The Windows Azure SDK 2.2 we released two weeks ago introduced remote debugging support for Windows Azure Cloud Services. With today’s Windows Azure release we are extending this remote debugging support to also work with Windows Azure Web Sites. With live, remote debugging support inside of Visual Studio, you are able to have more visibility than ever before into how your code is operating live in Windows Azure. It is now super easy to attach the debugger and quickly see what is going on with your application in the cloud. Remote Debugging of a Windows Azure Web Site using VS 2013 Enabling the remote debugging of a Windows Azure Web Site using VS 2013 is really easy.  Start by opening up your web application’s project within Visual Studio. Then navigate to the “Server Explorer” tab within Visual Studio, and click on the deployed web-site you want to debug that is running within Windows Azure using the Windows Azure->Web Sites node in the Server Explorer.  Then right-click and choose the “Attach Debugger” option on it: When you do this Visual Studio will remotely attach the debugger to the Web Site running within Windows Azure.  The debugger will then stop the web site’s execution when it hits any break points that you have set within your web application’s project inside Visual Studio.  For example, below I set a breakpoint on the “ViewBag.Message” assignment statement within the HomeController of the standard ASP.NET MVC project template.  When I hit refresh on the “About” page of the web site within the browser, the breakpoint was triggered and I am now able to debug the app remotely using Visual Studio: Note above how we can debug variables (including autos/watchlist/etc), as well as use the Immediate and Command Windows. In the debug session above I used the Immediate Window to explore some of the request object state, as well as to dynamically change the ViewBag.Message property.  When we click the the “Continue” button (or press F5) the app will continue execution and the Web Site will render the content back to the browser.  This makes it super easy to debug web apps remotely. Tips for Better Debugging To get the best experience while debugging, we recommend publishing your site using the Debug configuration within Visual Studio’s Web Publish dialog. This will ensure that debug symbol information is uploaded to the Web Site which will enable a richer debug experience within Visual Studio.  You can find this option on the Web Publish dialog on the Settings tab: When you ultimately deploy/run the application in production we recommend using the “Release” configuration setting – the release configuration is memory optimized and will provide the best production performance.  To learn more about diagnosing and debugging Windows Azure Web Sites read our new Troubleshooting Windows Azure Web Sites in Visual Studio guide. Notification Hubs: Segmented Push Notification support with tag expressions In August we announced the General Availability of Windows Azure Notification Hubs - a powerful Mobile Push Notifications service that makes it easy to send high volume push notifications with low latency from any mobile app back-end.  Notification hubs can be used with any mobile app back-end (including ones built using our Mobile Services capability) and can also be used with back-ends that run in the cloud as well as on-premises. Beginning with the initial release, Notification Hubs allowed developers to send personalized push notifications to both individual users as well as groups of users by interest, by associating their devices with tags representing the logical target of the notification. For example, by registering all devices of customers interested in a favorite MLB team with a corresponding tag, it is possible to broadcast one message to millions of Boston Red Sox fans and another message to millions of St. Louis Cardinals fans with a single API call respectively. New support for using tag expressions to enable advanced customer segmentation With today’s release we are adding support for even more advanced customer targeting.  You can now identify customers that you want to send push notifications to by defining rich tag expressions. With tag expressions, you can now not only broadcast notifications to Boston Red Sox fans, but take that segmenting a step farther and reach more granular segments. This opens up a variety of scenarios, for example: Offers based on multiple preferences—e.g. send a game day vegetarian special to users tagged as both a Boston Red Sox fan AND a vegetarian Push content to multiple segments in a single message—e.g. rain delay information only to users who are tagged as either a Boston Red Sox fan OR a St. Louis Cardinal fan Avoid presenting subsets of a segment with irrelevant content—e.g. season ticket availability reminder to users who are tagged as a Boston Red Sox fan but NOT also a season ticket holder To illustrate with code, consider a restaurant chain app that sends an offer related to a Red Sox vs Cardinals game for users in Boston. Devices can be tagged by your app with location tags (e.g. “Loc:Boston”) and interest tags (e.g. “Follows:RedSox”, “Follows:Cardinals”), and then a notification can be sent by your back-end to “(Follows:RedSox || Follows:Cardinals) && Loc:Boston” in order to deliver an offer to all devices in Boston that follow either the RedSox or the Cardinals. This can be done directly in your server backend send logic using the code below: var notification = new WindowsNotification(messagePayload); hub.SendNotificationAsync(notification, "(Follows:RedSox || Follows:Cardinals) && Loc:Boston"); In your expressions you can use all Boolean operators: AND (&&), OR (||), and NOT (!).  Some other cool use cases for tag expressions that are now supported include: Social: To “all my group except me” - group:id && !user:id Events: Touchdown event is sent to everybody following either team or any of the players involved in the action: Followteam:A || Followteam:B || followplayer:1 || followplayer:2 … Hours: Send notifications at specific times. E.g. Tag devices with time zone and when it is 12pm in Seattle send to: GMT8 && follows:thaifood Versions and platforms: Send a reminder to people still using your first version for Android - version:1.0 && platform:Android For help on getting started with Notification Hubs, visit the Notification Hub documentation center.  Then download the latest NuGet package (or use the Notification Hubs REST APIs directly) to start sending push notifications using tag expressions.  They are really powerful and enable a bunch of great new scenarios. TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services With today’s Windows Azure release we are making it really easy to enable continuous delivery support with Windows Azure and Team Foundation Services.  Team Foundation Services is a cloud based offering from Microsoft that provides integrated source control (with both TFS and Git support), build server, test execution, collaboration tools, and agile planning support.  It makes it really easy to setup a team project (complete with automated builds and test runners) in the cloud, and it has really rich integration with Visual Studio. With today’s Windows Azure release it is now really easy to enable continuous delivery support with both TFS and Git based repositories hosted using Team Foundation Services.  This enables a workflow where when code is checked in, built successfully on an automated build server, and all tests pass on it – I can automatically have the app deployed on Windows Azure with zero manual intervention or work required. The below screen-shots demonstrate how to quickly setup a continuous delivery workflow to Windows Azure with a Git-based ASP.NET MVC project hosted using Team Foundation Services. Enabling Continuous Delivery to Windows Azure with Team Foundation Services The project I’m going to enable continuous delivery with is a simple ASP.NET MVC project whose source code I’m hosting using Team Foundation Services.  I did this by creating a “SimpleContinuousDeploymentTest” repository there using Git – and then used the new built-in Git tooling support within Visual Studio 2013 to push the source code to it.  Below is a screen-shot of the Git repository hosted within Team Foundation Services: I can access the repository within Visual Studio 2013 and easily make commits with it (as well as branch, merge and do other tasks).  Using VS 2013 I can also setup automated builds to take place in the cloud using Team Foundation Services every time someone checks in code to the repository: The cool thing about this is that I don’t have to buy or rent my own build server – Team Foundation Services automatically maintains its own build server farm and can automatically queue up a build for me (for free) every time someone checks in code using the above settings.  This build server (and automated testing) support now works with both TFS and Git based source control repositories. Connecting a Team Foundation Services project to Windows Azure Once I have a source repository hosted in Team Foundation Services with Automated Builds and Testing set up, I can then go even further and set it up so that it will be automatically deployed to Windows Azure when a source code commit is made to the repository (assuming the Build + Tests pass).  Enabling this is now really easy.  To set this up with a Windows Azure Web Site simply use the New->Compute->Web Site->Custom Create command inside the Windows Azure Management Portal.  This will create a dialog like below.  I gave the web site a name and then made sure the “Publish from source control” checkbox was selected: When we click next we’ll be prompted for the location of the source repository.  We’ll select “Team Foundation Services”: Once we do this we’ll be prompted for our Team Foundation Services account that our source repository is hosted under (in this case my TFS account is “scottguthrie”): When we click the “Authorize Now” button we’ll be prompted to give Windows Azure permissions to connect to the Team Foundation Services account.  Once we do this we’ll be prompted to pick the source repository we want to connect to.  Starting with today’s Windows Azure release you can now connect to both TFS and Git based source repositories.  This new support allows me to connect to the “SimpleContinuousDeploymentTest” respository we created earlier: Clicking the finish button will then create the Web Site with the continuous delivery hooks setup with Team Foundation Services.  Now every time someone pushes source control to the repository in Team Foundation Services, it will kick off an automated build, run all of the unit tests in the solution , and if they pass the app will be automatically deployed to our Web Site in Windows Azure.  You can monitor the history and status of these automated deployments using the Deployments tab within the Web Site: This enables a really slick continuous delivery workflow, and enables you to build and deploy apps in a really nice way. Developer Analytics: New Relic support for Web Sites + Mobile Services With today’s Windows Azure release we are making it really easy to enable Developer Analytics and Monitoring support with both Windows Azure Web Site and Windows Azure Mobile Services.  We are partnering with New Relic, who provide a great dev analytics and app performance monitoring offering, to enable this - and we have updated the Windows Azure Management Portal to make it really easy to configure. Enabling New Relic with a Windows Azure Web Site Enabling New Relic support with a Windows Azure Web Site is now really easy.  Simply navigate to the Configure tab of a Web Site and scroll down to the “developer analytics” section that is now within it: Clicking the “add-on” button will display some additional UI.  If you don’t already have a New Relic subscription, you can click the “view windows azure store” button to obtain a subscription (note: New Relic has a perpetually free tier so you can enable it even without paying anything): Clicking the “view windows azure store” button will launch the integrated Windows Azure Store experience we have within the Windows Azure Management Portal.  You can use this to browse from a variety of great add-on services – including New Relic: Select “New Relic” within the dialog above, then click the next button, and you’ll be able to choose which type of New Relic subscription you wish to purchase.  For this demo we’ll simply select the “Free Standard Version” – which does not cost anything and can be used forever:  Once we’ve signed-up for our New Relic subscription and added it to our Windows Azure account, we can go back to the Web Site’s configuration tab and choose to use the New Relic add-on with our Windows Azure Web Site.  We can do this by simply selecting it from the “add-on” dropdown (it is automatically populated within it once we have a New Relic subscription in our account): Clicking the “Save” button will then cause the Windows Azure Management Portal to automatically populate all of the needed New Relic configuration settings to our Web Site: Deploying the New Relic Agent as part of a Web Site The final step to enable developer analytics using New Relic is to add the New Relic runtime agent to our web app.  We can do this within Visual Studio by right-clicking on our web project and selecting the “Manage NuGet Packages” context menu: This will bring up the NuGet package manager.  You can search for “New Relic” within it to find the New Relic agent.  Note that there is both a 32-bit and 64-bit edition of it – make sure to install the version that matches how your Web Site is running within Windows Azure (note: you can configure your Web Site to run in either 32-bit or 64-bit mode using the Web Site’s “Configuration” tab within the Windows Azure Management Portal): Once we install the NuGet package we are all set to go.  We’ll simply re-publish the web site again to Windows Azure and New Relic will now automatically start monitoring the application Monitoring a Web Site using New Relic Now that the application has developer analytics support with New Relic enabled, we can launch the New Relic monitoring portal to start monitoring the health of it.  We can do this by clicking on the “Add Ons” tab in the left-hand side of the Windows Azure Management Portal.  Then select the New Relic add-on we signed-up for within it.  The Windows Azure Management Portal will provide some default information about the add-on when we do this.  Clicking the “Manage” button in the tray at the bottom will launch a new browser tab and single-sign us into the New Relic monitoring portal associated with our account: When we do this a new browser tab will launch with the New Relic admin tool loaded within it: We can now see insights into how our app is performing – without having to have written a single line of monitoring code.  The New Relic service provides a ton of great built-in monitoring features allowing us to quickly see: Performance times (including browser rendering speed) for the overall site and individual pages.  You can optionally set alert thresholds to trigger if the speed does not meet a threshold you specify. Information about where in the world your customers are hitting the site from (and how performance varies by region) Details on the latency performance of external services your web apps are using (for example: SQL, Storage, Twitter, etc) Error information including call stack details for exceptions that have occurred at runtime SQL Server profiling information – including which queries executed against your database and what their performance was And a whole bunch more… The cool thing about New Relic is that you don’t need to write monitoring code within your application to get all of the above reports (plus a lot more).  The New Relic agent automatically enables the CLR profiler within applications and automatically captures the information necessary to identify these.  This makes it super easy to get started and immediately have a rich developer analytics view for your solutions with very little effort. If you haven’t tried New Relic out yet with Windows Azure I recommend you do so – I think you’ll find it helps you build even better cloud applications.  Following the above steps will help you get started and deliver you a really good application monitoring solution in only minutes. Service Bus: Support for partitioned queues and topics With today’s release, we are enabling support within Service Bus for partitioned queues and topics. Enabling partitioning enables you to achieve a higher message throughput and better availability from your queues and topics. Higher message throughput is achieved by implementing multiple message brokers for each partitioned queue and topic.  The  multiple messaging stores will also provide higher availability. You can create a partitioned queue or topic by simply checking the Enable Partitioning option in the custom create wizard for a Queue or Topic: Read this article to learn more about partitioned queues and topics and how to take advantage of them today. Billing: New Billing Alert Service Today’s Windows Azure update enables a new Billing Alert Service Preview that enables you to get proactive email notifications when your Windows Azure bill goes above a certain monetary threshold that you configure.  This makes it easier to manage your bill and avoid potential surprises at the end of the month. With the Billing Alert Service Preview, you can now create email alerts to monitor and manage your monetary credits or your current bill total.  To set up an alert first sign-up for the free Billing Alert Service Preview.  Then visit the account management page, click on a subscription you have setup, and then navigate to the new Alerts tab that is available: The alerts tab allows you to setup email alerts that will be sent automatically once a certain threshold is hit.  For example, by clicking the “add alert” button above I can setup a rule to send myself email anytime my Windows Azure bill goes above $100 for the month: The Billing Alert Service will evolve to support additional aspects of your bill as well as support multiple forms of alerts such as SMS.  Try out the new Billing Alert Service Preview today and give us feedback. Summary Today’s Windows Azure release enables a ton of great new scenarios, and makes building applications hosted in the cloud even easier. If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using all of the above features today.  Then visit the Windows Azure Developer Center to learn more about how to build apps with it. 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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• Sorting Algorithms

  - by MarkPearl

  General Every time I go back to university I find myself wading through sorting algorithms and their implementation in C++. Up to now I haven’t really appreciated their true value. However as I discovered this last week with Dictionaries in C# – having a knowledge of some basic programming principles can greatly improve the performance of a system and make one think twice about how to tackle a problem. I’m going to cover briefly in this post the following: Selection Sort Insertion Sort Shellsort Quicksort Mergesort Heapsort (not complete) Selection Sort Array based selection sort is a simple approach to sorting an unsorted array. Simply put, it repeats two basic steps to achieve a sorted collection. It starts with a collection of data and repeatedly parses it, each time sorting out one element and reducing the size of the next iteration of parsed data by one. So the first iteration would go something like this… Go through the entire array of data and find the lowest value Place the value at the front of the array The second iteration would go something like this… Go through the array from position two (position one has already been sorted with the smallest value) and find the next lowest value in the array. Place the value at the second position in the array This process would be completed until the entire array had been sorted. A positive about selection sort is that it does not make many item movements. In fact, in a worst case scenario every items is only moved once. Selection sort is however a comparison intensive sort. If you had 10 items in a collection, just to parse the collection you would have 10+9+8+7+6+5+4+3+2=54 comparisons to sort regardless of how sorted the collection was to start with. If you think about it, if you applied selection sort to a collection already sorted, you would still perform relatively the same number of iterations as if it was not sorted at all. Many of the following algorithms try and reduce the number of comparisons if the list is already sorted – leaving one with a best case and worst case scenario for comparisons. Likewise different approaches have different levels of item movement. Depending on what is more expensive, one may give priority to one approach compared to another based on what is more expensive, a comparison or a item move. Insertion Sort Insertion sort tries to reduce the number of key comparisons it performs compared to selection sort by not “doing anything” if things are sorted. Assume you had an collection of numbers in the following order… 10 18 25 30 23 17 45 35 There are 8 elements in the list. If we were to start at the front of the list – 10 18 25 & 30 are already sorted. Element 5 (23) however is smaller than element 4 (30) and so needs to be repositioned. We do this by copying the value at element 5 to a temporary holder, and then begin shifting the elements before it up one. So… Element 5 would be copied to a temporary holder 10 18 25 30 23 17 45 35 – T 23 Element 4 would shift to Element 5 10 18 25 30 30 17 45 35 – T 23 Element 3 would shift to Element 4 10 18 25 25 30 17 45 35 – T 23 Element 2 (18) is smaller than the temporary holder so we put the temporary holder value into Element 3. 10 18 23 25 30 17 45 35 – T 23   We now have a sorted list up to element 6. And so we would repeat the same process by moving element 6 to a temporary value and then shifting everything up by one from element 2 to element 5. As you can see, one major setback for this technique is the shifting values up one – this is because up to now we have been considering the collection to be an array. If however the collection was a linked list, we would not need to shift values up, but merely remove the link from the unsorted value and “reinsert” it in a sorted position. Which would reduce the number of transactions performed on the collection. So.. Insertion sort seems to perform better than selection sort – however an implementation is slightly more complicated. This is typical with most sorting algorithms – generally, greater performance leads to greater complexity. Also, insertion sort performs better if a collection of data is already sorted. If for instance you were handed a sorted collection of size n, then only n number of comparisons would need to be performed to verify that it is sorted. It’s important to note that insertion sort (array based) performs a number item moves – every time an item is “out of place” several items before it get shifted up. Shellsort – Diminishing Increment Sort So up to now we have covered Selection Sort & Insertion Sort. Selection Sort makes many comparisons and insertion sort (with an array) has the potential of making many item movements. Shellsort is an approach that takes the normal insertion sort and tries to reduce the number of item movements. In Shellsort, elements in a collection are viewed as sub-collections of a particular size. Each sub-collection is sorted so that the elements that are far apart move closer to their final position. Suppose we had a collection of 15 elements… 10 20 15 45 36 48 7 60 18 50 2 19 43 30 55 First we may view the collection as 7 sub-collections and sort each sublist, lets say at intervals of 7 10 60 55 – 20 18 – 15 50 – 45 2 – 36 19 – 48 43 – 7 30 10 55 60 – 18 20 – 15 50 – 2 45 – 19 36 – 43 48 – 7 30 (Sorted) We then sort each sublist at a smaller inter – lets say 4 10 55 60 18 – 20 15 50 2 – 45 19 36 43 – 48 7 30 10 18 55 60 – 2 15 20 50 – 19 36 43 45 – 7 30 48 (Sorted) We then sort elements at a distance of 1 (i.e. we apply a normal insertion sort) 10 18 55 60 2 15 20 50 19 36 43 45 7 30 48 2 7 10 15 18 19 20 30 36 43 45 48 50 55 (Sorted) The important thing with shellsort is deciding on the increment sequence of each sub-collection. From what I can tell, there isn’t any definitive method and depending on the order of your elements, different increment sequences may perform better than others. There are however certain increment sequences that you may want to avoid. An even based increment sequence (e.g. 2 4 8 16 32 …) should typically be avoided because it does not allow for even elements to be compared with odd elements until the final sort phase – which in a way would negate many of the benefits of using sub-collections. The performance on the number of comparisons and item movements of Shellsort is hard to determine, however it is considered to be considerably better than the normal insertion sort. Quicksort Quicksort uses a divide and conquer approach to sort a collection of items. The collection is divided into two sub-collections – and the two sub-collections are sorted and combined into one list in such a way that the combined list is sorted. The algorithm is in general pseudo code below… Divide the collection into two sub-collections Quicksort the lower sub-collection Quicksort the upper sub-collection Combine the lower & upper sub-collection together As hinted at above, quicksort uses recursion in its implementation. The real trick with quicksort is to get the lower and upper sub-collections to be of equal size. The size of a sub-collection is determined by what value the pivot is. Once a pivot is determined, one would partition to sub-collections and then repeat the process on each sub collection until you reach the base case. With quicksort, the work is done when dividing the sub-collections into lower & upper collections. The actual combining of the lower & upper sub-collections at the end is relatively simple since every element in the lower sub-collection is smaller than the smallest element in the upper sub-collection. Mergesort With quicksort, the average-case complexity was O(nlog2n) however the worst case complexity was still O(N*N). Mergesort improves on quicksort by always having a complexity of O(nlog2n) regardless of the best or worst case. So how does it do this? Mergesort makes use of the divide and conquer approach to partition a collection into two sub-collections. It then sorts each sub-collection and combines the sorted sub-collections into one sorted collection. The general algorithm for mergesort is as follows… Divide the collection into two sub-collections Mergesort the first sub-collection Mergesort the second sub-collection Merge the first sub-collection and the second sub-collection As you can see.. it still pretty much looks like quicksort – so lets see where it differs… Firstly, mergesort differs from quicksort in how it partitions the sub-collections. Instead of having a pivot – merge sort partitions each sub-collection based on size so that the first and second sub-collection of relatively the same size. This dividing keeps getting repeated until the sub-collections are the size of a single element. If a sub-collection is one element in size – it is now sorted! So the trick is how do we put all these sub-collections together so that they maintain their sorted order. Sorted sub-collections are merged into a sorted collection by comparing the elements of the sub-collection and then adjusting the sorted collection. Lets have a look at a few examples… Assume 2 sub-collections with 1 element each 10 & 20 Compare the first element of the first sub-collection with the first element of the second sub-collection. Take the smallest of the two and place it as the first element in the sorted collection. In this scenario 10 is smaller than 20 so 10 is taken from sub-collection 1 leaving that sub-collection empty, which means by default the next smallest element is in sub-collection 2 (20). So the sorted collection would be 10 20 Lets assume 2 sub-collections with 2 elements each 10 20 & 15 19 So… again we would Compare 10 with 15 – 10 is the winner so we add it to our sorted collection (10) leaving us with 20 & 15 19 Compare 20 with 15 – 15 is the winner so we add it to our sorted collection (10 15) leaving us with 20 & 19 Compare 20 with 19 – 19 is the winner so we add it to our sorted collection (10 15 19) leaving us with 20 & _ 20 is by default the winner so our sorted collection is 10 15 19 20. Make sense? Heapsort (still needs to be completed) So by now I am tired of sorting algorithms and trying to remember why they were so important. I think every year I go through this stuff I wonder to myself why are we made to learn about selection sort and insertion sort if they are so bad – why didn’t we just skip to Mergesort & Quicksort. I guess the only explanation I have for this is that sometimes you learn things so that you can implement them in future – and other times you learn things so that you know it isn’t the best way of implementing things and that you don’t need to implement it in future. Anyhow… luckily this is going to be the last one of my sorts for today. The first step in heapsort is to convert a collection of data into a heap. After the data is converted into a heap, sorting begins… So what is the definition of a heap? If we have to convert a collection of data into a heap, how do we know when it is a heap and when it is not? The definition of a heap is as follows: A heap is a list in which each element contains a key, such that the key in the element at position k in the list is at least as large as the key in the element at position 2k +1 (if it exists) and 2k + 2 (if it exists). Does that make sense? At first glance I’m thinking what the heck??? But then after re-reading my notes I see that we are doing something different – up to now we have really looked at data as an array or sequential collection of data that we need to sort – a heap represents data in a slightly different way – although the data is stored in a sequential collection, for a sequential collection of data to be in a valid heap – it is “semi sorted”. Let me try and explain a bit further with an example… Example 1 of Potential Heap Data Assume we had a collection of numbers as follows 1[1] 2[2] 3[3] 4[4] 5[5] 6[6] For this to be a valid heap element with value of 1 at position [1] needs to be greater or equal to the element at position [3] (2k +1) and position [4] (2k +2). So in the above example, the collection of numbers is not in a valid heap. Example 2 of Potential Heap Data Lets look at another collection of numbers as follows 6[1] 5[2] 4[3] 3[4] 2[5] 1[6] Is this a valid heap? Well… element with the value 6 at position 1 must be greater or equal to the element at position [3] and position [4]. Is 6 > 4 and 6 > 3? Yes it is. Lets look at element 5 as position 2. It must be greater than the values at [4] & [5]. Is 5 > 3 and 5 > 2? Yes it is. If you continued to examine this second collection of data you would find that it is in a valid heap based on the definition of a heap.

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• CodePlex Daily Summary for Wednesday, December 15, 2010

  CodePlex Daily Summary for Wednesday, December 15, 2010Popular ReleasesTweetSharp: TweetSharp v2.0.0.0 - Preview 5: Documentation for this release may be found at http://tweetsharp.codeplex.com/wikipage?title=UserGuide&referringTitle=Documentation. Note: This code is currently preview quality. Preview 5 ChangesMaintenance release with user reported fixes Preview 4 ChangesReintroduced fluent interface support via satellite assembly Added entities support, entity segmentation, and ITweetable/ITweeter interfaces for client development Numerous fixes reported by preview users Preview 3 ChangesNumerous ...SQL Monitor: SQL Monitor 2.8: 1. redesigned the object explorer, support multiple serversEnhSim: EnhSim 2.2.2 ALPHA: 2.2.2 ALPHAThis release adds in the changes for 4.03a at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - The spirit ...FlickrNet API Library: 3.1.4000: Newest release. Now contains dedicated Windows Phone 7 DLL as well as all previous DLLs. Also contains Windows Help file documentation now as standard.mojoPortal: 2.3.5.8: see release notes on mojoportal.com http://www.mojoportal.com/mojoportal-2358-released.aspx Note that we have separate deployment packages for .NET 3.5 and .NET 4.0 The deployment package downloads on this page are pre-compiled and ready for production deployment, they contain no C# source code. To download the source code see the Source Code Tab I recommend getting the latest source code using TortoiseHG, you can get the source code corresponding to this release here.Microsoft All-In-One Code Framework: Visual Studio 2010 Code Samples 2010-12-13: Code samples for Visual Studio 2010SuperSocket, an extensible socket application framework: SuperSocket 1.3 beta 1: SuperSocket 1.3 is built on .NET 4.0 framework. Bug fixes: fixed a potential bug that the running state hadn't been updated after socket server stopped fixed a synchronization issue when clearing timeout session fixed a bug in ArraySegmentList fixed a bug on getting configuration value Third-part library upgrades: upgraded SuperSocket to .NET 4.0 upgraded EntLib 4.1 to 5.0 New features: supported UDP socket support custom protocol (can support binary protocol and other complecate...Wii Backup Fusion: Wii Backup Fusion 0.9 Beta: - Aqua or brushed metal style for Mac OS X - Shows selection count beside ID - Game list selection mode via settings - Compare Files <-> WBFS game lists - Verify game images/DVD/WBFS - WIT command line for log (via settings) - Cancel possibility for loading games process - Progress infos while loading games - Localization for dates - UTF-8 support - Shortcuts added - View game infos in browser - Transfer infos for log - All transfer routines rewritten - Extract image from image/WBFS - Support....NETTER Code Starter Pack: v1.0.beta: '.NETTER Code Starter Pack ' contains a gallery of Visual Studio 2010 solutions leveraging latest and new technologies and frameworks based on Microsoft .NET Framework. Each Visual Studio solution included here is focused to provide a very simple starting point for cutting edge development technologies and framework, using well known Northwind database (for database driven scenarios). The current release of this project includes starter samples for the following technologies: ASP.NET Dynamic...WPF Multiple Document Interface (MDI): Beta Release v1.1: WPF.MDI is a library to imitate the traditional Windows Forms Multiple Document Interface (MDI) features in WPF. This is Beta release, means there's still work to do. Please provide feedback, so next release will be better. Features: Position dependency property MdiLayout dependency property Menu dependency property Ctrl + F4, Ctrl + Tab shortcuts should work Behavior: don’t allow negative values for MdiChild position minimized windows: remember position, tile multiple windows, ...SQL Server PowerShell Extensions: 2.3.1 Production: Release 2.3.1 implements SQLPSX as PowersShell version 2.0 modules. SQLPSX consists of 12 modules with 155 advanced functions, 2 cmdlets and 7 scripts for working with ADO.NET, SMO, Agent, RMO, SSIS, SQL script files, PBM, Performance Counters, SQLProfiler and using Powershell ISE as a SQL and Oracle query tool. In addition optional backend databases and SQL Server Reporting Services 2008 reports are provided with SQLServer and PBM modules. See readme file for details.NuGet (formerly NuPack): NuGet 1.0 Release Candidate: NuGet is a free, open source developer focused package management system for the .NET platform intent on simplifying the process of incorporating third party libraries into a .NET application during development. This release is a Visual Studio 2010 extension and contains the the Package Manager Console and the Add Package Dialog. This new build targets the newer feed (http://go.microsoft.com/fwlink/?LinkID=206669) and package format. See http://nupack.codeplex.com/documentation?title=Nuspe...Free Silverlight & WPF Chart Control - Visifire: Visifire Silverlight, WPF Charts v3.6.5 Released: Hi, Today we are releasing final version of Visifire, v3.6.5 with the following new feature: * New property AutoFitToPlotArea has been introduced in DataSeries. AutoFitToPlotArea will bring bubbles inside the PlotArea in order to avoid clipping of bubbles in bubble chart. You can visit Visifire documentation to know more. http://www.visifire.com/visifirechartsdocumentation.php Also this release includes few bug fixes: * Chart threw exception while adding new Axis in Chart using Vi...PHPExcel: PHPExcel 1.7.5 Production: DonationsDonate via PayPal via PayPal. If you want to, we can also add your name / company on our Donation Acknowledgements page. PEAR channelWe now also have a full PEAR channel! Here's how to use it: New installation: pear channel-discover pear.pearplex.net pear install pearplex/PHPExcel Or if you've already installed PHPExcel before: pear upgrade pearplex/PHPExcel The official page can be found at http://pearplex.net. Want to contribute?Please refer the Contribute page.SwapWin: SwapWin 0.2: Updates: Bring all windows that are swapped to foreground. Make the window sent to primary screen active.??????????: All-In-One Code Framework ??? 2010-12-10: ?????All-In-One Code Framework（??） 2010?12??????！！http://i3.codeplex.com/Project/Download/FileDownload.aspx?ProjectName=1code&DownloadId=128165 ?????release?，???????ASP.NET, WinForm, Silverlight????12?Sample Code。???，??????????sample code。 ?????：http://blog.csdn.net/sjb5201/archive/2010/12/13/6072675.aspx ??，??????MSDN????????????。 http://social.msdn.microsoft.com/Forums/zh-CN/codezhchs/threads ?????????????????，??Email ????DNN Simple Article: DNNSimpleArticle Module V00.00.03: The initial release of the DNNSimpleArticle module (labelled V00.00.03) There are C# and VB versions of this module for this initial release. No promises that going forward there will be packages for both languages provided for future releases. This module provides the following functionality Create and display articles Display a paged list of articles Articles get created as DNN ContentItems Categorization provided through DNN Taxonomy SEO functionality for article display providi...AutoLoL: AutoLoL v1.4.3: AutoLoL now supports importing the build pages from Mobafire.com as well! Just insert the url to the build and voila. (For example: http://www.mobafire.com/league-of-legends/build/unforgivens-guide-how-to-build-a-successful-mordekaiser-24061) Stable release of AutoChat (It is still recommended to use with caution and to read the documentation) It is now possible to associate *.lolm files with AutoLoL to quickly open them The selected spells are now displayed in the masteries tab for qu...SubtitleTools: SubtitleTools 1.2: - Added auto insertion of RLE (RIGHT-TO-LEFT EMBEDDING) Unicode character for the RTL languages. - Fixed delete rows issue.PHP Manager for IIS: PHP Manager 1.1 for IIS 7: This is a final stable release of PHP Manager 1.1 for IIS 7. This is a minor incremental release that contains all the functionality available in 53121 plus additional features listed below: Improved detection logic for existing PHP installations. Now PHP Manager detects the location to php.ini file in accordance to the PHP specifications Configuring date.timezone. PHP Manager can automatically set the date.timezone directive which is required to be set starting from PHP 5.3 Ability to ...New Projectscomplile: compiler is bestComputer Graphics: Esercitazioni di Computer GraficaDocsVision WorkFlow Extended Library: ?????? ??????, ???????????? ????? ??????????, ??????????? ????? ?????? ? DocsVision.WorkFlow.Gates. ?????????? ?????????? ????????????? ???????-????????? ? ????? DocsVision. ??????????? ??????: - DVTypeConverter; - DVCardProperty.DotNetNuke Razor Forum Profile: A razor based module for DotNetNuke that displays a user's forum profile information (based on the core forum). Excel AddIn to reset the last worksheet cell: This is a sample Excel AddIn to reset the last worsheet cell in an Excel Workbook.FriendFeed Backup Creator: FriendFeed Backup Creator makes it easier for friendfeed users to backup their feeds including likes and comments. You'll no longer have to worry about your old feeds.Gerins: Sistema Gerencial InsolGoodreads for Windows Phone 7: Goodreads client for Windows Phone 7HyperView for DotNetNuke: HyperView for DotNetNuke is a port of the MIT Exhibit project for DotNetNuke. Exhibit enables web site authors to easily create dynamic exhibits of collections. The collections can be searched and browsed using faceted browsing.Ladder Ranking System: A ladder ranking system as a DotNetNuke moduleLive Office Tools: <LOT - Live Office Tools> makes it easier for <target user group> to <Escritórios>. You'll no longer have to <activity>. It's developed in <C#>. LostMamory: ???????GIS??My WP7 Brand: My WP7 Brand is a simple Windows Phone 7 Template that allows users to view your rss feed, your tweet and your contact's info.Network Adapter/ Interface Analyzer, viewer, Speed Calculator: Simple .Net Application to give information about all network adapters in the system, their running status, max speed, download upload speed, etcOnlineenquete: Online enquete is an application based based on BeeldbankMVC. This project will be used as a starting point for creating my online survay toolOpalis Extension Exchange Mail: A Opalis Integration Pack allowing for Exachange 2007 and 2010 mail manipulation functions. Uses Exchange Webservices.PAK: A Sample project for windows Phone 7, Azure and K2 blackpearl.Persephone CMS: // TODO: Some description to be displayed here!!!Perspectives: Perspectives makes it easier for Visual Studio 2010 users to manage window configurations. It's developed in C#. It was modeled after the Eclipse Perspectives window management system.Photo Studio: Photo studio for storing family albumsPorto Alegre Dojo: Porto Alegre DojoRazor's Edge DotNetNuke User Map: Razor's Edge User Map allows you to load your DotnetNuke user's locations on to a map dynamically based on the address in their user profile. It uses the razor scripting language to retrieve user data and display that data on the page.RestUpMVC: RestUpMVC is a library that allows developers to easily expose a RESTful interface from an ASP.NET MVC application. The library was written in C#.Rocket Framework for Windows Form: Rocket Framework winform .net 4.0 WPF generic entity framework repositoryRPG Maplestory XNA SDK C#: a RPG Maplestory XNA SDK makes it easier for all people want to devolopded a Platform rpg in XNA - C# Sistema para Manejo de Maquinas: Sistema para controlar, insertar y almacenar datos.SoloForum: SoloForumUpdate SharePoint 2010 User Personal Settings: Every SharePoint user will have his/her personal settings for a site collection. Each user can view their details by clicking on Logged-in User link and select My Settings menu item. This tool helps to update user personal settings for a particular site collection.uREST 4 Umbraco: uREST is an Umbraco package for adding a set of RESTful web services to an Umbraco website.Veller: This is a high speed game where speed is your ally. The faster you go the more damage you do. You are vulnerable when moving slow, but gain momentum. Windows Forms Wizard: Oddly, the Windows Forms libraries don't provide any support for writing wizards. Here's one way to do it. Yes!gama NewCMS: Yes!gama NewCMS is a simple news CMS Builded by asp.net + access very very simple... maybe u like simlpe tings...

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