Search Results

Search found 5267 results on 211 pages for 'use cases'.

Page 87/211 | < Previous Page | 83 84 85 86 87 88 89 90 91 92 93 94  | Next Page >

• "Oracle Coherence 3.5" Book - My Humble Review

  - by [email protected]

    After reviewing the book in more detail I say again that it is a great guide for sure. Lots of important concepts that sometimes can be somewhat confusing are deeply reviewed, including all types of caching schemes and backing maps, and the cache topologies with their corresponding performances and very useful "When to use it?" sections. Some functionalities that are very desirable or used a lot are reviewed with examples and best practices of implementation, including: Data affinity Querying Pagination Indexes Aggregations Event processing, listening and triggering Data persistence Security Regarding the networking and architecture topics, Coherence*Extend is exhaustively reviewed, including C++ and .NET clients, with very good tips and examples, even including source codes. Personally, I am also glad to see that the address providers (<address-provider> tag), new feature in Coherence 3.5 which is a way to programmatically provide well-known addresses in order to connect to the cluster, is mentioned on the book, because it provides new functionalities to satisfy some special configuration requirements for example: Provide a way to switch extend nodes in cases of failure Implement custom load balancing algorithms and/or dynamic discovery of TCP/IP connection acceptors Dynamically assign TCP address and port settings when binding to a server socket Another very interesting and useful section is the "Coherent Bank Sample Application", which is a great tutorial, useful to understand how Coherence interacts with third party products establishing a clear integration with them, including the use of non-Oracle products like MS Visual Studio.  

  Read the article

• How to implment the database for event conditions and item bonuses for a browser based game

  - by Saifis

  I am currently creating a browser based game, and was wondering what was the standard approach in making diverse conditions and status bonuses database wise. Currently considering two cases. Event Conditions Needs min 1000 gold Needs min Lv 10 Needs certain item. Needs fulfillment of another event Status Bonus Reduces damage by 20% +100 attack points Deflects certain type of attack I wish to be able to continually change these parameters during the process of production and operation, so having them hard-coded isn't the best way. All I could come up with are the following two methods. Method 1 Create a table that contains each conditions with needed attributes Have a model named conditions with all the attributes it would need to set them conditions condition_type (level, money_min, money_max item, event_aquired) condition_amount prerequisite_condition_id prerequisite_item_id Method 2 write it in a DSL form that could be interpreted later in the code Perhaps something like yaml, have a text area in the setting form and have the code interpret it. condition_foo: condition_type :level min_level: 10 condition_type :item item_id: 2 At current Method 2 looks to be more practical and flexible for future changes, trade off being that all the flex must be done on the code side. Not to sure how this is supposed to be done, is it supposed to be hard coded? separate config file? Any help would be appreciated. Added For additional info, it will be implemented with Ruby on Rails

  Read the article

• How do you keep SOA DRY?

  - by TaylorOtwell

  In our organization, we've shifted to a more "service oriented architecture". To give an example, let's assume we need to retrieve a "Quote" object. This quote has a shipper, a consignee, phone numbers, contacts, email addresses, and other location information. In other words, a Quote object is made up of many other objects. So, it seems like it would make sense to make a "Quote Retrieval Service". In our situation, we've accomplished this by creating a .NET solution and writing the service. The service API looks something like this (in pseudo-code): Function GetQuote(String ID) Returns Quote So, so far so good. Now, when this service is consumed, to keep things "de-coupled", we are creating essentially a duplicate of the Quote object and mapping from the QuoteService version of the Quote into the consumer's version of the Quote. In many cases, these classes will have the exact same properties. So, if the Quote service is consumed by 5 other applications, we would have 6 definitions of what a "Quote" is. One for each consumer, and one for the service. This feels wrong. I thought code was supposed to be DRY, but it seems like our method of SOA is forcing us to create tons of duplicated class definitions. What are we doing wrong, or is the code duplication just a "necessary evil" of SOA?

  Read the article

• VBScript and Xpath excluding duplicates [closed]

  - by Malachi

  I am trying to pull names from an XML Document using a vbscript. XML Document structure <Aliases> <Alias PartyType="DF" CaseID="000000" NameType=""> Name Name</Alias> <Alias PartyType="DF" CaseID="000000" NameType=""> Name Name</Alias> <Alias PartyType="DF" CaseID="000000" NameType=""> Name Name</Alias> ... </Aliases> the XML File might have 100 rows with the same name coming from several different CaseID's because for this part of my vbscript I am trying to pull all the different Names from all cases, but here is the issue, I don't want to return duplicates. is there a way to do this with an xPath Expression or should I try to do this with VBScript? EDIT I am pretty sure that I am going to have to do this with VBScript. Would it be Faster and more efficient to solve this issue in VBScript, xPath, or in populating the XML I am retrieving information from ( this might prove more difficult than the other two options ) I am also asking a Similar question on stackoverflow

  Read the article

• can canonical links be used to make 'duplicate' pages unique?

  - by merk

  We have a website that allows users to list items for sale. Think ebay - except we don't actually deal with selling the item, we just list it for sale and provide a way to contact the seller. Anyhow, in several cases sellers maybe have multiple units of an item for sale. We don't have a quantity field, so they upload each item as a separate listing (and using a quantity field is not an option). So we have a lot of pages which basically have the exact same info and only the item # might be different. The SEO guy we've started using has said we should put a canonical link on each page, and have the canonical link point to itself. So for example, www.mysite.com/something/ would have a canonical link of href="www.mysite.com/something/" This doesn't really seem kosher to me. I thought canonical links we're suppose to point to other pages. The SEO guy claims doing it this way will tell google all these pages are indeed unique, even if they do basically have the same content. This seems a little off to me since what's to stop a spammer from putting up a million pages and doing this as well? Can anyone tell me if the SEO guy's suggestion is valid or not? If it's not valid, then do i need to figure out some way to check for duplicated items and automatically pick one of the duplicates to serve as an original and generate canonical links based off that? Thanks in advance for any help

  Read the article

• How to handle fine grained field-based ACL permissions in a RESTful service?

  - by Jason McClellan

  I've been trying to design a RESTful API and have had most of my questions answered, but there is one aspect of permissions that I'm struggling with. Different roles may have different permissions and different representations of a resource. For example, an Admin or the user himself may see more fields in his own User representation vs another less-privileged user. This is achieved simply by changing the representation on the backend, ie: deciding whether or not to include those fields. Additionally, some actions may be taken on a resource by some users and not by others. This is achieved by deciding whether or not to include those action items as links, eg: edit and delete links. A user who does not have edit permissions will not have an edit link. That covers nearly all of my permission use cases, but there is one that I've not quite figured out. There are some scenarios whereby for a given representation of an object, all fields are visible for two or more roles, but only a subset of those roles my edit certain fields. An example: { "person": { "id": 1, "name": "Bob", "age": 25, "occupation": "software developer", "phone": "555-555-5555", "description": "Could use some sunlight.." } } Given 3 users: an Admin, a regular User, and Bob himself (also a regular User), I need to be able to convey to the front end that: Admins may edit all fields, Bob himself may edit all fields, but a regular User, while they can view all fields, can only edit the description field. I certainly don't want the client to have to make the determination (or even, for that matter, to have any notion of the roles involved) but I do need a way for the backend to convey to the client which fields are editable. I can't simply use a combination of representation (the fields returned for viewing) and links (whether or not an edit link is availble) in this scenario since it's more finely grained. Has anyone solved this elegantly without adding the logic directly to the client?

  Read the article

• Count function on tree structure (non-binary)

  - by Spevy

  I am implementing a tree Data structure in c# based (largely on Dan Vanderboom's Generic implementation). I am now considering approach on handling a Count property which Dan does not implement. The obvious and easy way would be to use a recursive call which Traverses the tree happily adding up nodes (or iteratively traversing the tree with a Queue and counting nodes if you prefer). It just seems expensive. (I also may want to lazy load some of my nodes down the road). I could maintain a count at the root node. All children would traverse up to and/or hold a reference to the root, and update a internally settable count property on changes. This would push the iteration problem to when ever I want to break off a branch or clear all children below a given node. Generally less expensive, and puts the heavy lifting what I think will be less frequently called functions. Seems a little brute force, and that usually means exception cases I haven't thought of yet, or bugs if you prefer. Does anyone have an example of an implementation which keeps a count for an Unbalanced and/or non-binary tree structure rather than counting on the fly? Don't worry about the lazy load, or language. I am sure I can adjust the example to fit my specific needs. EDIT: I am curious about an example, rather than instructions or discussion. I know this is not technically difficult...

  Read the article

• Should we test all our methods?

  - by Zenzen

  So today I had a talk with my teammate about unit testing. The whole thing started when he asked me "hey, where are the tests for that class, I see only one?". The whole class was a manager (or a service if you prefer to call it like that) and almost all the methods were simply delegating stuff to a DAO so it was similar to: SomeClass getSomething(parameters) { return myDao.findSomethingBySomething(parameters); } A kind of boilerplate with no logic (or at least I do not consider such simple delegation as logic) but a useful boilerplate in most cases (layer separation etc.). And we had a rather lengthy discussion whether or not I should unit test it (I think that it is worth mentioning that I did fully unit test the DAO). His main arguments being that it was not TDD (obviously) and that someone might want to see the test to check what this method does (I do not know how it could be more obvious) or that in the future someone might want to change the implementation and add new (or more like "any") logic to it (in which case I guess someone should simply test that logic). This made me think, though. Should we strive for the highest test coverage %? Or is it simply an art for art's sake then? I simply do not see any reason behind testing things like: getters and setters (unless they actually have some logic in them) "boilerplate" code Obviously a test for such a method (with mocks) would take me less than a minute but I guess that is still time wasted and a millisecond longer for every CI. Are there any rational/not "flammable" reasons to why one should test every single (or as many as he can) line of code?

  Read the article

• The year ahead, 2011.

  - by andrewstopford

  When I look back at last years look at 2010 my blogging rate has not changed much (I suspect this is largely down to using Twitter a lot) but my interests this year have developed a lot further. My view on 2010 would be that Microsoft would commit more to OSS, while I wanted to see more hires from that audience and more projects on Outercurve foundation instead there has been support for JQuery and Gems (aka NuGet). I would love to see more from Microsoft on the OSS front in 2011, Outercurve could become like the Apache foundation with enough support. Staying on the Microsoft front I predict that 2011 will bring the following. C# 5.0 will go RTM (still no MOP though) The next release of VS will go alpha or early beta MS MVC 4.0 (I think by Mix time) and maybe this release will get a command line. I also suspect that Microsoft will want to target the tablet market with WP7 in 2011 (Mix 2011 maybe...). I also predict the following Java will fork with Apache\Google. Oracle will then take them to court and the whole thing will boil right through 2011 (Java have had enough court cases, come on guys). Java and the JVM will sadly not move forward at all in 2011. Android will cause Apple a serious headache, both the smartphone and tablet market will see figures cut from Apple share. By the end of 2011 the current 70% apple market share will be 40-50%. As the features, performance and price of Android devices gets ever better Apple will be left out in the open. Lastly after 7 years I intend to move this blog away from weblogs. In 2011 I will be exploring Java, Ruby\Rails and Android and such subjects don't make sense to talk about it here. See you in 2011.

  Read the article

• Spreading incoming batched data into a real-time stream

  - by pr1001

  I would like to display some events in 'real-time'. However, I must fetch the data from another source. I can request the last X minutes, though the source is updated approximately every 5 minutes. This means that there will be a delay between the most recent data retrieved and the point in time that I make the request. Second, because I will be receiving a batch of data, I don't want to just fire out all the events down a socket once my fetcher has retrieved it: I would like to spread out the events so that they are both accurately spaced amongst each other and in sync with their original occurrences (e.g. an event is always displayed 6 minutes after it actually happened). My thought is to fetch the data every 5 minutes from the source, knowing that I won't get the very latest data. The original data would be then queued to be sent down the socket 7.5 minutes from its original timestamp – that is, at least ~2.5 minutes from when its batch was fetched and at most 7.5 minutes since then. My question is this: is this the best way to approach the problem? Does this problem have any standard approaches or associated literature related to implementation best-practices and edge cases? I am a bit worried that the frequency of my fetches and the frequency in which the source is updated will get out of sync, leading to points where no data will be retrieved from the source. However, since my socket delay is greater than my fetch frequency, the subsequent fetch should retrieve newer data before the socket queue is empty. Is that correct? Am I missing something? Thanks!

  Read the article

• Facebook Payments & Credits vs. Real-World & Charities

  - by Adam Tannon

  I am having a difficult time understanding Facebook's internal "e-commerce microcosm" and what it allows Facebook App developers to do (and what it restricts them from doing). Two use cases: I'm an e-com retailer selling clothes and coffee mugs (real-world goods) on my website; I want to write a Facebook App that allows Facebook users to buy my real-world goods from inside of Facebook using real money ($ USD) I'm highschool student trying to raise money for my senior class trip and want to build a Facebook App that allows Facebook users to donate to our class using real money ($ USD) Are these two scenarios possible? If not, why (what Facebook policies prohibit me from doing so)? If so, what APIs do I use: Payments or Credits? And how (specifically) would it work? Do Facebook Users have to first buy "credits" (which are mapped to $ USD values under the hood) and pay/donate with credits, or can they whip out their credit card and pay/donate right through my Facebook App? I think that last question really summarizes my confusion: can Facebook users enter their credit card info directly into Facebook Apps, or do you have to go through Payments/Credits APIs as a "middleman"?

  Read the article

• Impact on SEO of adding categories/tags in front of the HTML title [closed]

  - by Mad Scientist

  Possible Duplicate: Does the order of keywords matter in a page title? All StackExchange sites add the most-used tag of a question in front of the HTML title for SEO purposes. On Stackoverflow for example this is usually the programming language, so you end up with a title like python - How do I do X? This has obviously an enourmous benefit on SEO as the programming language is an extremely important keyword that is very often omitted from the title. Now, my question is for the cases where the tag isn't an important keyword missing from the title, but just a category. So on Biology.SE for example one would have questions like biochemistry - How does protein X interact with Y? or on Skeptics medical science - Do vaccines cause autism? Those tags are usually not part of the search terms, they serve to categorize the content but users don't use those tags in their searches. How harmful is adding tags that are not used in searches in terms of SEO? Is there any hard data on the impact this practise might have on SEO? The negative aspects I can imagine, but have no data to show that it is actually a problem are: I heard that search engines dislike keyword stuffing and this might trigger some defense mechanisms against that It's a practise associated with less reputable sites, a keyword in front that doesn't fit the actual title well might look suspicious to some users. It wastes precious space in the title shown in search results.

  Read the article

• How do I position a 2D camera in OpenGL?

  - by Elfayer

  I can't understand how the camera is working. It's a 2D game, so I'm displaying a game map from (0, 0, 0) to (mapSizeX, 0, mapSizeY). I'm initializing the camera as follow : Camera::Camera(void) : position_(0.0f, 0.0f, 0.0f), rotation_(0.0f, 0.0f, -1.0f) {} void Camera::initialize(void) { glMatrixMode(GL_PROJECTION); glLoadIdentity(); glTranslatef(position_.x, position_.y, position_.z); gluPerspective(70.0f, 800.0f/600.0f, 1.0f, 10000.0f); gluLookAt(0.0f, 6000.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LEQUAL); } So the camera is looking down. I currently see the up right border of the map in the center of my window and the map expand to the down left border of my window. I would like to center the map. The logical thing to do should be to move the camera to eyeX = mapSizeX / 2 and the same for z. My map has 10 x 10 cases with CASE = 400, so I should have : gluLookAt((10 / 2) * CASE /* = 2000 */, 6000.0f, (10 / 2) * CASE /* = 2000 */, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f); But that doesn't move the camera, but seems to rotate it. Am I doing something wrong? EDIT : I tried that: gluLookAt(2000.0f, 6000.0f, 0.0f, 2000.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f); Which correctly moves the map in the middle of the window in width. But I can't move if correctly in height. It always returns the axis Z. When I go up, It goes down and the same for right and left. I don't see the map anymore when I do : gluLookAt(2000.0f, 6000.0f, 2000.0f, 2000.0f, 0.0f, 2000.0f, 0.0f, 1.0f, 0.0f);

  Read the article

• Compressing/compacting messages over websocket on Node.js

  - by icelava

  We have a websocket implementation (Node.js/Sock.js) that exchanges data as JSON strings. As our use cases grow, so have the size of the data transmitted across the wire. The websocket protocol does not natively offer any compression feature, so in order to reduce the size of our messages we'd have to manually do something about the serialisation. There appear to be a variety of LZW implementations in Javascript, some which confuses me on their compatibility for in-browser use only versus transmission across the wire due to my lack of understanding on low-level encodings. More importantly, all of them seem to take a noticeable performance drag when Javascript is the engine doing the compression/decompression work, which is not desirable for mobile devices. Looking instead other forms of compact serialisation, MessagePack does not appear to have any active support in Javascript itself; BSON does not have any Javascript implementation; and an alternative BISON project that I tested does not deserialise everything back to their original values (large numbers), and it does not look like any further development will happen either. What are some other options others have explored for Node.js?

  Read the article

• Overloading methods that do logically different things, does this break any major principles?

  - by siva.k

  This is something that's been bugging me for a bit now. In some cases you see code that is a series of overloads, but when you look at the actual implementation you realize they do logically different things. However writing them as overloads allows the caller to ignore this and get the same end result. But would it be more sound to name the methods more explicitly then to write them as overloads? public void LoadWords(string filePath) { var lines = File.ReadAllLines(filePath).ToList(); LoadWords(lines); } public void LoadWords(IEnumerable<string> words) { // loads words into a List<string> based on some filters } Would these methods better serve future developers to be named as LoadWordsFromFile() and LoadWordsFromEnumerable()? It seems unnecessary to me, but if that is better what programming principle would apply here? On the flip side it'd make it so you didn't need to read the signatures to see exactly how you can load the words, which as Uncle Bob says would be a double take. But in general is this type of overloading to be avoided then?

  Read the article

• Thoughts on type aliases/synonyms?

  - by Rei Miyasaka

  I'm going to try my best to frame this question in a way that doesn't result in a language war or list, because I think there could be a good, technical answer to this question. Different languages support type aliases to varying degrees. C# allows type aliases to be declared at the beginning of each code file, and they're valid only throughout that file. Languages like ML/Haskell use type aliases probably as much as they use type definitions. C/C++ are sort of a Wild West, with typedef and #define often being used seemingly interchangeably to alias types. The upsides of type aliasing don't invoke too much dispute: It makes it convenient to define composite types that are described naturally by the language, e.g. type Coordinate = float * float or type String = [Char]. Long names can be shortened: using DSBA = System.Diagnostics.DebuggerStepBoundaryAttribute. In languages like ML or Haskell, where function parameters often don't have names, type aliases provide a semblance of self-documentation. The downside is a bit more iffy: aliases can proliferate, making it difficult to read and understand code or to learn a platform. The Win32 API is a good example, with its DWORD = int and its HINSTANCE = HANDLE = void* and its LPHANDLE = HANDLE FAR* and such. In all of these cases it hardly makes any sense to distinguish between a HANDLE and a void pointer or a DWORD and an integer etc.. Setting aside the philosophical debate of whether a king should give complete freedom to their subjects and let them be responsible for themselves or whether they should have all of their questionable actions intervened, could there be a happy medium that would allow the benefits of type aliasing while mitigating the risk of its abuse? As an example, the issue of long names can be solved by good autocomplete features. Visual Studio 2010 for instance will alllow you to type DSBA in order to refer Intellisense to System.Diagnostics.DebuggerStepBoundaryAttribute. Could there be other features that would provide the other benefits of type aliasing more safely?

  Read the article

• How should I describe the process of learning someone else's code? (In an invoicing situation.)

  - by MattyG

  I have a contract to upgrade some in-house software for a large company. The company has requested multiple feature additions and a few bug fixes. This is my first freelance style job. First, I needed to become familiar with how the application worked - I learnt it as if I was a user. Next, I had to learn how the software worked. I started with broad concepts, and then narrowed down into necessary detail before working on each bug fix and feature. At least at the start of the project, it took me a lot longer to learn the existing code than it did to write the additional features. How can I describe the process of learning the existing code on the invoice? (This part of the company usually does things in-house, so doesn't have much experience dealing with software contractors like me, and I fear they may not understand the overhead of learning someone else's code). I don't want to just tack the learning time onto the actual feature upgrade, because in some cases this would make a 'simple task' look like it took me way too long. I want break the invoice into relevant steps, and communicate that I'm charging for the large overhead of learning someone else's code before being able to add my own to it. Is there a standard way of describing this sort of activity when billing for a job?

  Read the article

• Ubiquitous Language and Custom types

  - by EdvRusj

  Note that my question is referring to those attributes that even on their own already represent a concept ( ie on their own provide a cohesive meaning ). Thus such attribute needs no additional functional support and as such is self-contained. I'm also well-aware that even with self-contained attributes the custom types may prove beneficial ( for example, they give the ability to add new behavior later, when business requirements change ). Thus, my question focuses only on whether custom types for self-contained attributes really enrich Ubiquitous Language UL a) I've read that in most cases, even simple, self-contained attributes should have custom, more descriptive types rather than basic value types ( double, string ... ), because among other things, descriptive types add to the UL, while the use of basic types instead weakens the language. I understand the importance of UL, but how does having a basic type for a self-contained attribute weaken the language, since with self-contained attributes the name of the attribute already adequately describes the concept and thus contributes to the UL vocabulary? For example, the term person_age already adequately explains the concept of quantifying the number of years a person has: class Person { string person_age; } so what could we possibly gain by also introducing the term ThingAge to the UL: class person { ThingAge person_age; } thanks

  Read the article

• How to handle monetary values in PHP and MySql?

  - by Songo

  I've inherited a huge pile of legacy code written in PHP on top of a MySQL database. The thing I noticed is that the application uses doubles for storage and manipulation of data. Now I came across of numerous posts mentioning how double are not suited for monetary operations because of the rounding errors. However, I have yet to come across a complete solution to how monetary values should be handled in PHP code and stored in a MySQL database. Is there a best practice when it comes to handling money specifically in PHP? Things I'm looking for are: How should the data be stored in the database? column type? size? How should the data be handling in normal addition, subtraction. multiplication or division? When should I round the values? How much rounding is acceptable if any? Is there a difference between handling large monetary values and low ones? Note: A VERY simplified sample code of how I might encounter money values in everyday life: $a= $_POST['price_in_dollars']; //-->(ex: 25.06) will be read as a string should it be cast to double? $b= $_POST['discount_rate'];//-->(ex: 0.35) value will always be less than 1 $valueToBeStored= $a * $b; //--> any hint here is welcomed $valueFromDatabase= $row['price']; //--> price column in database could be double, decimal,...etc. $priceToPrint=$valueFromDatabase * 0.25; //again cast needed or not? I hope you use this sample code as a means to bring out more use cases and not to take it literally of course. Bonus Question If I'm to use an ORM such as Doctrine or PROPEL, how different will it be to use money in my code.

  Read the article

• How do I find information on who links to my sites?

  - by bobdobbs

  I'm trying to figure out if there's a free way to get information on backlinks to my site. I've had webmaster tools and google analytics set up for years. But I can't find access to data about site backlinks in either toolset. Webmaster tools, under 'traffic'-'links to your site' gives me the same message for all of my sites: "No data available". I haven't been able to find anything in GA that gives any information on backlinks. I've heard of using "links:" as an operator in google search, but for each of my sites, this returns either zero or very few results in cases when I know I have many backlinks. Most of the links simple aren't shown. My thinking is that google maintains a graph of who links to my site, so I figured that they might let me see it. But I can't figure out how. I've found this tool on a spammy website: http://www.backlinkwatch.com. It offers more data than google on my backlines, and offers more results in exchange for a paid subscription. The data it offers for free looks good, but the results are limited and the site has popups and obnoxious ads. So, in short: how do I get data on who links to me? Is there a free way?

  Read the article

• Sucking Less Every Year ?

  - by AdityaGameProgrammer

  Sucking Less Every Year A trail of thought that had been on my mind for a while Quoting directly from the post I've often thought that sucking less every year is how humble programmers improve. You should be unhappy with code you wrote a year ago. If you aren't, that means either A) you haven't learned anything in a year, B) your code can't be improved, or C) you never revisit old code. All of these are the kiss of death for software developers. How often does this happen or not happen to you? How long before you see an actual improvement in your coding ? month, year? Do you ever revisit Your old code? How often does your old code plague you? or how often do you have to deal with your technical debt. It is definitely very painful to fix old bugs n dirty code that we may have done to quickly meet a deadline and those quick fixes ,some cases we may have to rewrite most of the application/code. No arguments about that. Some of the developers i had come across argued that they were already at the evolved stage where their coding doesn't need improvement or cant get improved anymore. Does this happen? If so how many years into coding on a particular language does one expect this to happen?

  Read the article

• How to represent a graph with multiple edges allowed between nodes and edges that can selectively disappear

  - by Pops

  I'm trying to figure out what sort of data structure to use for modeling some hypothetical, idealized network usage. In my scenario, a number of users who are hostile to each other are all trying to form networks of computers where all potential connections are known. The computers that one user needs to connect may not be the same as the ones another user needs to connect, though; user 1 might need to connect computers A, B and D while user 2 might need to connect computers B, C and E. Image generated with the help of NCTM Graph Creator I think the core of this is going to be an undirected cyclic graph, with nodes representing computers and edges representing Ethernet cables. However, due to the nature of the scenario, there are a few uncommon features that rule out adjacency lists and adjacency matrices (at least, without non-trivial modifications): edges can become restricted-use; that is, if one user acquires a given network connection, no other user may use that connection in the example, the green user cannot possibly connect to computer A, but the red user has connected B to E despite not having a direct link between them in some cases, a given pair of nodes will be connected by more than one edge in the example, there are two independent cables running from D to E, so the green and blue users were both able to connect those machines directly; however, red can no longer make such a connection if two computers are connected by more than one cable, each user may own no more than one of those cables I'll need to do several operations on this graph, such as: determining whether any particular pair of computers is connected for a given user identifying the optimal path for a given user to connect target computers identifying the highest-latency computer connection for a given user (i.e. longest path without branching) My first thought was to simply create a collection of all of the edges, but that's terrible for searching. The best thing I can think to do now is to modify an adjacency list so that each item in the list contains not only the edge length but also its cost and current owner. Is this a sensible approach? Assuming space is not a concern, would it be reasonable to create multiple copies of the graph (one for each user) rather than a single graph?

  Read the article

• Visually and audibly unambiguous subset of the Latin alphabet?

  - by elliot42

  Imagine you give someone a card with the code "5SBDO0" on it. In some fonts, the letter "S" is difficult to visually distinguish from the number five, (as with number zero and letter "O"). Reading the code out loud, it might be difficult to distinguish "B" from "D", necessitating saying "B as in boy," "D as in dog," or using a "phonetic alphabet" instead. What's the biggest subset of letters and numbers that will, in most cases, both look unambiguous visually and sound unambiguous when read aloud? Background: We want to generate a short string that can encode as many values as possible while still being easy to communicate. Imagine you have a 6-character string, "123456". In base 10 this can encode 10^6 values. In hex "1B23DF" you can encode 16^6 values in the same number of characters, but this can sound ambiguous when read aloud. ("B" vs. "D") Likewise for any string of N characters, you get (size of alphabet)^N values. The string is limited to a length of about six characters, due to wanting to fit easily within the capacity of human working memory capacity. Thus to find the max number of values we can encode, we need to find that largest unambiguous set of letters/numbers. There's no reason we can't consider the letters G-Z, and some common punctuation, but I don't want to have to go manually pairwise compare "does G sound like A?", "does G sound like B?", "does G sound like C" myself. As we know this would be O(n^2) linguistic work to do =)...

  Read the article

• 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!

  Read the article

• You may be tempted by IaaS, but you should PaaS on that or your database cloud journey will be a short one

  - by B R Clouse

  Before we examine Consolidation, the next step in the journey to cloud, let's take a short detour to address a critical choice you will face at the outset of your journey: whether to deploy your databases in virtual machines or not. A common misconception we've encountered is the belief that moving to cloud computing can be accomplished by simply hosting one's current operating environment as-is within virtual machines, and then stacking those VMs together in a consolidated environment.  This solution is often described as "Infrastructure as a Service" (IaaS) because the building block for deployments is a VM, which behaves like a full complement of infrastructure.  This approach is easy to understand and may feel like a good first step, but it won't take your databases very far in the journey to cloud computing.  In fact, if you follow the IaaS fork in the road, your journey will end quickly, without realizing the full benefits of cloud computing.  The better option to is to rationalize the deployment stack so that VMs are needed only for exceptional cases.  By settling on a standard operating system and patch level, you create an infrastructure that potentially all of your databases can share.  Now, the building block will be database instances or possibly schemas within databases.  These components are the platforms on which you will deploy workloads, hence this is known as "Platform as a Service" (PaaS). PaaS opens the door to higher degrees of consolidation than IaaS, because with PaaS you will not need to accommodate the footprint (operating system, hypervisor, processes, ...) that each VM brings with it.  You will also reduce your maintenance overheard if you move forward without the VMs and their O/Ses to patch and monitor.  So while IaaS simply shuffles complex and varied environments into VMs,  PaaS actually reduces complexity by rationalizing to the small possible set of components.  Now we're ready to look at the consolidation options that PaaS provides -- in our next blog posting.

  Read the article

< Previous Page | 83 84 85 86 87 88 89 90 91 92 93 94  | Next Page >