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• Ubuntu 12.04 does not see windows already install on my computer (dual installation)

  - by jacinta

  I was trying to install the ubuntu 12.4 along side windows 7 on my new HP Pavilion 64k desktop with windows 7 computer but Ubuntu said that ( This computer has no detected operating system) and some one said (I suggest you chkdsk your Windows partition. I also suggest you resize the NTFS in WIndows then install Ubuntu to the free space.) Therefore I did (To shrink a simple or spanned volume using the Windows interface In Disk Management, right-click the simple or spanned volume you want to shrink. Click Shrink Volume…. Follow the instructions on your screen.) Then When I try to install ubuntu 12.4 after doing this, I received the same error. I was going to undo what I did but I see that I lose 1g when I do that so now what do I do? it says I can do a new simple volume and maybe then the space will no longer be unallocated. Please help me. I think I have a bad cd (ubuntu 12.4) cause from my research I see that I am not suppose to get a screen saying that (The computer has no detected operating system) I think this is a bad cd and I hope I did not mess up my computer. Please help. .................................................................................... O k I think I am following what you said about how to edit my question irrational john. I did chkdsk as you and actionparsnip (andrew-woodhead666) told me to AND ALSO did a lot of other things before I found out how to chkdsk. No problems. Thank you. Then I put back the space (extended) I took from system. I still was only able to put back 15 and not 16 so it is up to 99mb not back to 100mb. Then I shrank HP (C) as you told me, to 10 13,240 mb which is (12.93gb Unallocated). I did not change it into NTSF by doing the (New Simple Volume Action) I just left it. Then I tried to install UBUNTU 12.04 live CD amd64 and it gave me the results it was sometimes giving me before which is result (THAT Ubuntu) does not tell me weather I have or have not an already installed windows7. It just goes to a window that would have showed me information on what I have and on the bottom (DEVICE FOR BOOT LOADER INSTALLATION /dev/sda ) and the option to go BACK, QUIT, or INSTALL. (I think it is the INSTALLATION TYPE window). Therefore I do what I have been doing and I QUIT. What do I do now? Sorry that it seems like I cannot do anything on my own. On the Youtube video how to install ubuntu dual-boot alongside windows UBUNTU is installed so easy. The installation option page gives 3 options including dual instillation and the disk even lets you use a slider to slide to the size of the partition size you want. Yet my UBUNTU live cd is a mess and I checked it as one of you guys told me and got back information that it is good. Oh well this guy says you should press a control key to tell which device you are using to install ubuntu before the screen comes up. I guess cause it is old. This page also shows you easy stuff that do not show up on my cd. how to dual-boot UBUNTU and windows 7 P.S.. I saw this on the windows 7 website windows.microsoft.com/en-US/windows7/Formatting-disks-and-drives-frequently-asked-questions CREATE A BOOT PARTITION I HAD TO LEAVE OUT THE HTTP STUFF CAUSE I AM ONLY ALLOWED 2 ON A PAGE IT SAID To create a boot partition Warning Warning If you are installing different versions of Windows, you must install the earliest version first. If you don't do this, your computer may become inoperable. Open Computer Management by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Security, clicking Administrative Tools, and then double-clicking Computer Management.? Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation. In the left pane, under Storage, click Disk Management. Right-click an unallocated region on your hard disk, and then click New Simple Volume. In the New Simple Volume Wizard, click Next. Type the size of the volume you want to create in megabytes (MB) or accept the maximum default size, and then click Next. Accept the default drive letter or choose a different drive letter to identify the volume, and then click Next. In the Format Partition dialog box, do one of the following: If you don't want to format the volume right now, click Do not format this volume, and then click Next. To format the volume with the default settings, click Next. For more information about formatting, see Formatting disks and drives: frequently asked questions. Review your choices, and then click Finish. AND THIS ON ANOTHER PAGE. Formatting disks and drives: frequently asked questions Hard disks, the primary storage devices on your computer, need to be formatted before you can use them. When you format a disk, you configure it with a file system so that Windows can store information on the disk. Hard disks in new computers running Windows are already formatted. If you buy an additional hard disk to expand the storage of your computer, you might need to format it. Storage devices such as USB flash drives and flash memory cards usually come preformatted by the manufacturer, so you probably won't need to format them. CDs and DVDs, on the other hand, use different formats from hard disks and removable storage devices. For information about formatting CDs and DVDs, see Which CD or DVD format should I use? Warning Warning Formatting erases any existing files on a hard disk. If you format a hard disk that has files on it, the files will be deleted. WHAT I DID WAS I GOT TO COMPUTER MANAGEMENT SECTION THEN I CLICKED ON DRIVE HP(C) (it put stripes on to show it is selected) Then I click on ACTION selected ALL TASKS AND THEN selected SHRINK VOLUME and then chose how much space from what it was giving me that I wanted. (12.93gb) AND THAT WAS ALL I DID. THEN I TRIED TO INSTALL UBUNTU i NEVER GOT THE 3RD SCREEN THAT IS IN THE VIDEO I INCLUDED (THE YOUTUBE WITH THE ENGLISH GUY) INSTALLATION TYPE I ALSO DID NOT GET THE 4TH SCREEN THAT ALLOWS YOU TO SELECT PARTITION SIZE what i got next was the 2nd INSTILLATION TYPE window shown on the (LINUX BS DOS.COM) PAGE THAT I INCLUDED and it showed no information about any drives (no drives /partition or stuff was shown) only the Boot Loader statement and the dev/sda bar and that's why i did not press install but chose to QUIT. SORRY I JUST NOW SAW YOUR ANSWER IRRATIONAL JOHN. I SHRANK HP(C) BY 12.93GB MY UNALLOCATED SPACE IS NOW 12.93GB HP(C) = 907.17gb NTSF...YOU ARE CORRECT WITH EVERYTHING YOU SAID This is what i read on (http://)windows.microsoft.com/en-US/windows7/Create-a-boot-partition I am only allowed 2 links Create a boot partition You must be logged on as an administrator to perform these steps. A boot partition is a partition that contains the files for the Windows operating system. If you want to install a second operating system on your computer (called a dual-boot or multiboot configuration), you need to create another partition on the hard disk, and then install the additional operating system on the new partition. Your hard disk would then have one system partition and two boot partitions. (A system partition is the partition that contains the hardware-related files. These tell the computer where to look to start Windows.) To create a partition on a basic disk, there must be unallocated disk space on your hard disk. With Disk Management, you can create a maximum of three primary partitions on a hard disk. You can create extended partitions, which include logical drives within them, if you need more partitions on the disk. Picture of disk space in Computer ManagementUnallocated disk space If there is no unallocated space, you will either need to create space by shrinking or deleting an existing partition or by using a third-party partitioning tool to repartition your hard disk. For more information, see Can I repartition my hard disk? To create a boot partition Warning Warning If you are installing different versions of Windows, you must install the earliest version first. If you don't do this, your computer may become inoperable. Open Computer Management by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Security, clicking Administrative Tools, and then double-clicking Computer Management.? Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation. In the left pane, under Storage, click Disk Management. Right-click an unallocated region on your hard disk, and then click New Simple Volume. In the New Simple Volume Wizard, click Next. Type the size of the volume you want to create in megabytes (MB) or accept the maximum default size, and then click Next. Accept the default drive letter or choose a different drive letter to identify the volume, and then click Next. In the Format Partition dialog box, do one of the following: If you don't want to format the volume right now, click Do not format this volume, and then click Next. To format the volume with the default settings, click Next. For more information about formatting, see Formatting disks and drives: frequently asked questions. Review your choices, and then click Finish. I did what you told me @irrational john and this is the screen shot. I ENTERED ubuntu@ubuntu:~$ sudo os-prober computer did not respond so I entered ubuntu@ubuntu:~$ sudo apt-get -y remove dmraid computer responded with Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: dmraid 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. After this operation, 141 kB disk space will be freed. (Reading database ... 147515 files and directories currently installed.) Removing dmraid ... update-initramfs is disabled since running on read-only media Processing triggers for man-db ... I entered ubuntu@ubuntu:~$ sudo os-prober Computer Responded with /dev/sda1:Windows 7 (loader):Windows:chain /dev/sda3:Windows Recovery Environment (loader):Windows1:chain ubuntu@ubuntu:~$ ............... @obsessiveFOSS I don't know what is a Grub menu and I do not know what is the Ubuntu boot option The answer you gave to me was correct. This one {This apparently removes the dmraid metadata. After doing that, you can use the desktop icon Install Ubuntu 12.04 LTS to start the Ubuntu installer. This time the Installation Type window should contain the option to Install Ubuntu alongside Windows 7.} This is what I decided to do. I did not see the rest of your help 'till now. Never the less. I think the best thing for me to do now is to get a cheap used laptop and either do a dual installation or just install Ubuntu on to it. This way if I have any issues that I cannot solve like the one I had here, at least I will still have a usable computer to work on and to use to get answers with because I am not an expert like the people on this forum. Thanks a lot I will try to keep learning and do research enough to some day help someone else.

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• sending a $_SESSION array to my class and attempting to get the value fro it in a for loop .php

  - by eoin

  i have a class which in which iam using a method to get information from a session array via a for loop the 2 for loops in each method are used 1.to count total amount of items , and 2. to add up the total price but neither seem to be returning anything. im using the total amount to check it against the mc_gross posted value from an IPN and if the values are equal i plan to commit the sale to a database as it has been verified. for the method where im looking to get the total price im getting 0.00 returned to me. i think ive got the syntax wrong here somehow here is my class for purchase the two methods iam having trouble with are the gettotalcost() and gettotalitems() shown below is my class. <?php class purchase { private $itemnames; // from session array private $amountofitems; // from session array private $itemcost; //session array private $saleid; //posted transaction id value to be used in sale and sale item tables private $orderdate; //get current date time to be entered as datetime in sale table private $lastname; //posted from ipn private $firstname; //posted from ipn private $emailadd; //uses sessionarray value public function __construct($saleid,$firstname,$lastname) { $this->itemnames = $_SESSION['itemnames']; $this->amountofitems =$_SESSION['quantity']; $this->itemcost =$_SESSION['price']; $this->saleid = $saleid; $this->firstname = $firstname; $this->lastname = $lastname; $this->emailadd = $SESSION['username']; mail($myemail, "session vardump ", echo var_dump($_SESSION), "From: [email protected]" ); mail($myemail, "session vardump ",count($_SESSION['itemnames']) , "From: [email protected]" ); } public function commit() { $databaseinst = database::getinstance(); $databaseinst->connect(); $numrows = $databaseinst->querydb($query); //to be completed } public function gettotalitems() { $numitems; $i; for($i=0; $i < count($this->amountofitems);$i++) { $numitems += (int) $this->amountofitems[$i]; } return $numitems; } public function gettotalcost() { $totalcost; $i; for($i=0; $i < count($this->amountofitems);$i++) { $numitems = (int) $this->amountofitems[$i]; $costofitem =doubleval($this->itemcost [$i]); $totalcost += $numitems * $costofitem; } return $totalcost; } } ?> and here is where i create an instance of the class and attempt to use it. include("purchase.php"); $purchase = new purchase($_POST['txn_id'],$_POST['first_name'],$_POST['last_name']); $fullamount = $purchase->gettotalcost(); $fullAmount = number_format($fullAmount, 2); $grossAmount = $_POST['mc_gross']; if ($fullAmount != $grossAmount) { $message = "Possible Price Jack attempt! the amount the customer payed is : " . $grossAmount . " which is not equal to the full amount. the price of the products combined is " . $fullAmount. " the transaction number for which is " . $_POST['txn_id'] . "\n\n\n$req"; mail("XXXXXXXXXXXX", "Price Jack attempt ", $message, "From: [email protected]" ); exit(); // exit } thanks for the help in advance! ive also added these lines to my constructor. the mail returns that there is nothing in the vardump uh oh! mail($myemailaddress, "session vardump ", var_dump($_SESSION), "From: [email protected]" ); also added session_start(); at the top of the constructor and it dont work! help

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• Agile Testing Days 2012 – Day 2 – Learn through disagreement

  - by Chris George

  I think I was in the right place! During Day 1 I kept on reading tweets about Lean Coffee that has happened earlier that morning. It intrigued me and I figured in for a penny in for a pound, and set my alarm for 6:45am. Following the award night the night before, it was _really_ hard getting up when it went off, but I did and after a very early breakfast, set off for the 10 min walk to the Dorint. With Lean Coffee due to start at 07:30, I arrived at the hotel and made my way to one of the hotel bars. I soon realised I was in the right place as although the bar was empty, there was a table with post-it’s and pens! This MUST be the place! The premise of Lean Coffee is to have several small timeboxed discussions. Everyone writes down what they would like to discuss on post-its that are then briefly explained and submitted to the pile. Once everyone is done, the group dot-votes on the topics. The topics are then sorted by the dot vote counts and the discussions begin. Each discussion had 8 mins to start with, which meant it prevented the discussions getting off topic too much. After the time elapsed, the group had a vote whether to extend the discussion by a further 4 mins or move on. Several discussion were had around training, soft skills etc. The conversations were really interesting and there were quite a few good ideas. Overall it was a very enjoyable experience, certainly worth the early start! Make Melly Happy Following Lean Coffee was real coffee, and much needed that was! The first keynote of the day was “Let’s help Melly (Changing Work into Life)”by Jurgen Appelo. Draw lines to track happiness This was a very interesting presentation, and set the day nicely. The theme to the keynote was projects are about the people, more-so than the actual tasks. So he started by showing a photo of an employee ‘Melly’ who looked happy enough. He then stated that she looked happy but actually hated her job. In fact 50% of Americans hate their jobs. He went on to say that the world over 50% of people hate Americans their jobs. Jurgen talked about many ways to reduce the feedback cycle, not only of the project, but of the people management. Ideas such as Happiness doors, happiness tracking (drawing lines on a wall indicating your happiness for that day), kudo boxes (to compliment a colleague for good work). All of these (and more) ideas stimulate conversation amongst the team, lead to early detection of issues and investigation of solutions. I’ve massively simplified Jurgen’s keynote and have certainly not done it justice, so I will post a link to the video once it’s available. Following more coffee, the next talk was “How releasing faster changes testing” by Alexander Schwartz. This is a topic very close to our hearts at the moment, so I was eager to find out any juicy morsels that could help us achieve more frequent releases, and Alex did not disappoint. He started off by confirming something that I have been a firm believer in for a number of years now; adding more people can do more harm than good when trying to release. This is for a number of reasons, but just adding new people to a team at such a critical time can be more of a drain on resources than they add. The alternative is to have the whole team have shared responsibility for faster delivery. So the whole team is responsible for quality and testing. Obviously you will have the test engineers on the project who have the specialist skills, but there is no reason that the entire team cannot do exploratory testing on the product. This links nicely with the Developer Exploratory testing presented by Sigge on Day 1, and certainly something that my team are really striving towards. Focus on cycle time, so what can be done to reduce the time between dev cycles, release cycles. What’s stops a release, what delays a release? all good solid questions that can be answered. Alex suggested that perhaps the product doesn’t need to be fully tested. Doing less testing will reduce the cycle time therefore get the release out faster. He suggested a risk-based approach to planning what testing needs to happen. Reducing testing could have an impact on revenue if it causes harm to customers, so test the ‘right stuff’! Determine a set of tests that are ‘face saving’ or ‘smoke’ tests. These tests cover the core functionality of the product and aim to prevent major embarrassment if these areas were to fail! Amongst many other very good points, Alex suggested that a good approach would be to release after every new feature is added. So do a bit of work -> release, do some more work -> release. By releasing small increments of work, the impact on the customer of bugs being introduced is reduced. Red Pill, Blue Pill The second keynote of the day was “Adaptation and improvisation – but your weakness is not your technique” by Markus Gartner and proved to be another very good presentation. It started off quoting lines from the Matrix which relate to adapting, improvising, realisation and mastery. It has alot of nerds in the room smiling! Markus went on to explain how through deliberate practice ( and a lot of it!) you can achieve mastery, but then you never stop learning. Through methods such as code retreats, testing dojos, workshops you can continually improve and learn. The code retreat idea was one that interested me. It involved pairing to write an automated test for, say, 45 mins, they deleting all the code, finding a different partner and writing the same test again! This is another keynote where the video will speak louder than anything I can write here! Markus did elaborate on something that Lisa and Janet had touched on yesterday whilst busting the myth that “Testers Must Code”. Whilst it is true that to be a tester, you don’t need to code, it is becoming more common that there is this crossover happening where more testers are coding and more programmers are testing. Markus made a special distinction between programmers and developers as testers develop tests code so this helped to make that clear. “Extending Continuous Integration and TDD with Continuous Testing” by Jason Ayers was my next talk after lunch. We already do CI and a bit of TDD on my project team so I was interested to see what this continuous testing thing was all about and whether it would actually work for us. At the start of the presentation I was of the opinion that it just would not work for us because our tests are too slow, and that would be the case for many people. Jason started off by setting the scene and saying that those doing TDD spend between 10-15% of their time waiting for tests to run. This can be reduced by testing less often, reducing the test time but this then increases the risk of introduced bugs not being spotted quickly. Therefore, in comes Continuous Testing (CT). CT systems run your unit tests whenever you save some code and runs them in the background so you can continue working. This is a really nice idea, but to do this, your tests must be fast, independent and reliable. The latter two should be the case anyway, and the first is ideal, but hard! Jason makes several suggestions to make tests fast. Firstly keep the scope of the test small, secondly spin off any expensive tests into a suite which is run, perhaps, overnight or outside of the CT system at any rate. So this started to change my mind, perhaps we could re-engineer our tests, and continuously run the quick ones to give an element of coverage. This talk was very interesting and I’ve already tried a couple of the tools mentioned on our product (Mighty Moose and NCrunch). Sadly due to the way our solution is built, it currently doesn’t work, but we will look at whether we can make this work because this has the potential to be a mini-game-changer for us. Using the wrong data Gojko’s Hierarchy of Quality The final keynote of the day was “Reinventing software quality” by Gojko Adzic. He opened the talk with the statement “We’ve got quality wrong because we are using the wrong data”! Gojko then went on to explain that we should judge a bug by whether the customer cares about it, not by whether we think it’s important. Why spend time fixing issues that the customer just wouldn’t care about and releasing months later because of this? Surely it’s better to release now and get customer feedback? This was another reference to the idea of how it’s better to build the right thing wrong than the wrong thing right. Get feedback early to make sure you’re making the right thing. Gojko then showed something which was very analogous to Maslow’s heirachy of needs. Successful – does it contribute to the business? Useful – does it do what the user wants Usable – does it do what it’s supposed to without breaking Performant/Secure – is it secure/is the performance acceptable Deployable Functionally ok – can it be deployed without breaking? He then explained that User Stories should focus on change. In other words they should focus on the users needs, not the users process. Describe what the change will be, how that change will happen then measure it! Networking and Beer Following the day’s closing keynote, there were drinks and nibble for the ‘Networking’ evening. This was a great opportunity to talk to people. I find approaching strangers very uncomfortable but once again, when in Rome! Pete Walen and I had a long conversation about only fixing issues that the customer cares about versus fixing issues that make you proud of your software! Without saying much, and asking the right questions, Pete made me re-evaluate my thoughts on the matter. Clever, very clever!  Oh and he ‘bought’ me a beer! My Takeaway Triple from Day 2: release small and release often to minimize issues creeping in and get faster feedback from ‘the real world’ Focus on issues that the customers care about, not what we think is important It’s okay to disagree with someone, even if they are well respected agile testing gurus, that’s how discussion and learning happens!  

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• initializing structs using user-input information

  - by johnny boy

  I am trying to make a program that works with poker (texas holdem) starting hands; each hand has a value from 1 to 169, and i want to be able to input each card and whether they are suited or not, and have those values correspond to a series of structs. Here is the code so far, i cant seem to get it to work (im a beginning programmer). oh and im using visual studio 2005 by the way #include "stdafx.h" #include <iostream> int main() { using namespace std; struct FirstCard { struct SecondCard { int s; //suited int n; //non-suited }; SecondCard s14; SecondCard s13; SecondCard s12; SecondCard s11; SecondCard s10; SecondCard s9; SecondCard s8; SecondCard s7; SecondCard s6; SecondCard s5; SecondCard s4; SecondCard s3; SecondCard s2; }; FirstCard s14; //ace FirstCard s13; //king FirstCard s12; //queen FirstCard s11; //jack FirstCard s10; FirstCard s9; FirstCard s8; FirstCard s7; FirstCard s6; FirstCard s5; FirstCard s4; FirstCard s3; FirstCard s2; s14.s14.n = 169; // these are the values that each combination s13.s13.n = 168; // will evaluate to, would eventually have s12.s12.n = 167; // hand combinations all the way down to 1 s11.s11.n = 166; s14.s13.s = 165; s14.s13.s = 164; s10.s10.n = 163; //10, 10, nonsuited s14.s13.n = 162; s14.s11.s = 161; s13.s12.s = 160;// king, queen, suited s9.s9.n = 159; s14.s10.s = 158; s14.s12.n = 157; s13.s11.s = 156; s8.s8.n = 155; s12.s11.s = 154; s13.s10.s = 153; s14.s9.s = 152; s14.s11.n = 151; cout << "enter first card: " << endl; cin >> somthing?//no idea what to put here, but this would somehow //read out the user input (a number from 2 to 14) //and assign it to the corresponding struct cout << firstcard.secondcard.suited_or_not << endl; //this would change depending //on what the user inputs system("Pause"); }

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• How do you stop scripters from slamming your website hundreds of times a second?

  - by davebug

  [update] I've accepted an answer, as lc deserves the bounty due to the well thought-out answer, but sadly, I believe we're stuck with our original worst case scenario: CAPTCHA everyone on purchase attempts of the crap. Short explanation: caching / web farms make it impossible for us to actually track hits, and any workaround (sending a non-cached web-beacon, writing to a unified table, etc.) slows the site down worse than the bots would. There is likely some pricey bit of hardware from Cisco or the like that can help at a high level, but it's hard to justify the cost if CAPTCHAing everyone is an alternative. I'll attempt to do a more full explanation in here later, as well as cleaning this up for future searchers (though others are welcome to try, as it's community wiki). I've added bounty to this question and attempted to explain why the current answers don't fit our needs. First, though, thanks to all of you who have thought about this, it's amazing to have this collective intelligence to help work through seemingly impossible problems. I'll be a little more clear than I was before: This is about the bag o' crap sales on woot.com. I'm the president of Woot Workshop, the subsidiary of Woot that does the design, writes the product descriptions, podcasts, blog posts, and moderates the forums. I work in the css/html world and am only barely familiar with the rest of the developer world. I work closely with the developers and have talked through all of the answers here (and many other ideas we've had). Usability of the site is a massive part of my job, and making the site exciting and fun is most of the rest of it. That's where the three goals below derive. CAPTCHA harms usability, and bots steal the fun and excitement out of our crap sales. To set up the scenario a little more, bots are slamming our front page tens of times a second screenscraping (and/or scanning our rss) for the Random Crap sale. The moment they see that, it triggers a second stage of the program that logs in, clicks I want One, fills out the form, and buys the crap. In current (2/6/2009) order of votes: lc: On stackoverflow and other sites that use this method, they're almost always dealing with authenticated (logged in) users, because the task being attempted requires that. On Woot, anonymous (non-logged) users can view our home page. In other words, the slamming bots can be non-authenticated (and essentially non-trackable except by IP address). So we're back to scanning for IPs, which a) is fairly useless in this age of cloud networking and spambot zombies and b) catches too many innocents given the number of businesses that come from one IP address (not to mention the issues with non-static IP ISPs and potential performance hits to trying to track this). Oh, and having people call us would be the worst possible scenario. Can we have them call you? BradC Ned Batchelder's methods look pretty cool, but they're pretty firmly designed to defeat bots built for a network of sites. Our problem is bots are built specifically to defeat our site. Some of these methods could likely work for a short time until the scripters evolved their bots to ignore the honeypot, screenscrape for nearby label names instead of form ids, and use a javascript-capable browser control. lc again "Unless, of course, the hype is part of you

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• overloaded stream insetion operator with a vector

  - by julz666

  hi, i'm trying to write an overloaded stream insertion operator for a class who's only member is a vector. i dont really know what i'm doing. (lets make that clear) it's a vector of "Points" which is a struct containing two doubles. i figure what i want is to insert user input (a bunch of doubles) into a stream that i then send to a modifier method? i keep working off other stream insertion examples such as... std::ostream& operator<< (std::ostream& o, Fred const& fred) { return o << fred.i_; } but when i try a similar..... istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr.vertices; return inStream; } i get an error "no match for operator etc etc. if i leave off the .vertices it compiles but i figure it's not right? (vertices is the name of my vector ) and even if it is right, i dont actually know what syntax to use in my driver to use it? also not %100 on what my modifier method needs to look like. here's my Polygon class //header #ifndef POLYGON_H #define POLYGON_H #include "Segment.h" #include <vector> class Polygon { friend std::istream & operator >> (std::istream &inStream, Polygon &vertStr); public: //Constructor Polygon(const Point &theVerts); //Default Constructor Polygon(); //Copy Constructor Polygon(const Polygon &polyCopy); //Accessor/Modifier methods inline std::vector<Point> getVector() const {return vertices;} //Return number of Vector elements inline int sizeOfVect() const {return (int) vertices.capacity();} //add Point elements to vector inline void setVertices(const Point &theVerts){vertices.push_back (theVerts);} private: std::vector<Point> vertices; }; #endif //Body using namespace std; #include "Polygon.h" // Constructor Polygon::Polygon(const Point &theVerts) { vertices.push_back (theVerts); } //Copy Constructor Polygon::Polygon(const Polygon &polyCopy) { vertices = polyCopy.vertices; } //Default Constructor Polygon::Polygon(){} istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr; return inStream; } any help greatly appreciated, sorry to be so vague, a lecturer has just kind of given us a brief example of stream insertion then left us on our own thanks. oh i realise there are probably many other problems that need fixing

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• ublas::bounded_vector<> being resized?

  - by n2liquid

  Now, seriously... I'll refrain from using bad words here because we're talking about the Boost fellows. It MUST be my mistake to see things this way, but I can't understand why, so I'll ask it here; maybe someone can enlighten me in this matter. Here it goes: uBLAS has this nice class template called bounded_vector<> that's used to create fixed-size vectors (or so I thought). From the Effective uBLAS wiki (http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Effective_UBLAS): The default uBLAS vector and matrix types are of variable size. Many linear algebra problems involve vectors with fixed size. 2 and 3 elements are common in geometry! Fixed size storage (akin to C arrays) can be implemented efficiently as it does not involve the overheads (heap management) associated with dynamic storage. uBLAS implements fixed sizes by changing the underling storage of a vector/matrix to a "bounded_array" from the default "unbounded_array". Alright, this bounded_vector<> thing is used to free you from specifying the underlying storage of the vector to a bounded_array<> of the specified size. Here I ask you: doesn't it look like this bounded vector thing has fixed size to you? Well, it doesn't have. At first I felt betrayed by the wiki, but then I reconsidered the meaning of "bounded" and I think I can let it pass. But in case you, like me (I'm still uncertain), is still wondering if this makes sense, what I found out is that the bounded_vector<> actually can be resized, it may only not be greater than the size specified as template parameter. So, first off, do you think they've had a good reason not to make a real fixed<< size vector or matrix type? Do you think it's okay to "sell" this bounded -- as opposed to fixed-size -- vector to the users of my library as a "fixed-size" vector replacement, even named "Vector3" or "Vector2", like the Effective uBLAS wiki did? Do you think I should somehow implement a vector with fixed size for this purpose? If so, how? (Sorry, but I'm really new to uBLAS; just tried it today) I am developing a 3D game. Should uBLAS be used for the calculations involved in this ("hey, geometry!", per Effective uBLAS wiki)? What replacement would you suggest, if not? -- edit And just in case, yes, I've read this warning: It should be noted that this only changes the storage uBLAS uses for the vector3. uBLAS will still use all the same algorithm (which assume a variable size) to manipulate the vector3. In practice this seems to have no negative impact on speed. The above runs just as quickly as a hand crafted vector3 which does not use uBLAS. The only negative impact is that the vector3 always store a "size" member which in this case is redundant [or isn't it? I mean......]. I see it uses the same algorithm, assuming a variable size, but if an operation were to actually change its size, shouldn't it be stopped (assertion)? ublas::bounded_vector<float,3> v3; ublas::bounded_vector<float,2> v2; v3 = v2; std::cout << v3.size() << '\n'; // prints 2 Oh, come on, isn't this just plain betrayal?

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• opengl 3d texture issue

  - by user1478217

  Hi i'm trying to use a 3d texture in opengl to implement volume rendering. Each voxel has an rgba colour value and is currently rendered as a screen facing quad.(for testing purposes). I just can't seem to get the sampler to give me a colour value in the shader. The quads always end up black. When I change the shader to generate a colour (based on xyz coords) then it works fine. I'm loading the texture with the following code: glGenTextures(1, &tex3D); glBindTexture(GL_TEXTURE_3D, tex3D); unsigned int colours[8]; colours[0] = Colour::AsBytes<unsigned int>(Colour::Blue); colours[1] = Colour::AsBytes<unsigned int>(Colour::Red); colours[2] = Colour::AsBytes<unsigned int>(Colour::Green); colours[3] = Colour::AsBytes<unsigned int>(Colour::Magenta); colours[4] = Colour::AsBytes<unsigned int>(Colour::Cyan); colours[5] = Colour::AsBytes<unsigned int>(Colour::Yellow); colours[6] = Colour::AsBytes<unsigned int>(Colour::White); colours[7] = Colour::AsBytes<unsigned int>(Colour::Black); glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, 2, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, colours); The colours array contains the correct data, i.e. the first four bytes have values 0, 0, 255, 255 for blue. Before rendering I bind the texture to the 2nd texture unit like so: glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_3D, tex3D); And render with the following code: shaders["DVR"]->Use(); shaders["DVR"]->Uniforms["volTex"].SetValue(1); shaders["DVR"]->Uniforms["World"].SetValue(Mat4(vl_one)); shaders["DVR"]->Uniforms["viewProj"].SetValue(cam->GetViewTransform() * cam->GetProjectionMatrix()); QuadDrawer::DrawQuads(8); I have used these classes for setting shader params before and they work fine. The quaddrawer draws eight instanced quads. The vertex shader code looks like this: #version 330 layout(location = 0) in vec2 position; layout(location = 1) in vec2 texCoord; uniform sampler3D volTex; ivec3 size = ivec3(2, 2, 2); uniform mat4 World; uniform mat4 viewProj; smooth out vec4 colour; void main() { vec3 texCoord3D; int num = gl_InstanceID; texCoord3D.x = num % size.x; texCoord3D.y = (num / size.x) % size.y; texCoord3D.z = (num / (size.x * size.y)); texCoord3D /= size; texCoord3D *= 2.0; texCoord3D -= 1.0; colour = texture(volTex, texCoord3D); //colour = vec4(texCoord3D, 1.0); gl_Position = viewProj * World * vec4(texCoord3D, 1.0) + (vec4(position.x, position.y, 0.0, 0.0) * 0.05); } uncommenting the line where I set the colour value equal to the texcoord works fine, and makes the quads coloured. The fragment shader is simply: #version 330 smooth in vec4 colour; out vec4 outColour; void main() { outColour = colour; } So my question is, what am I doing wrong, why is the sampler not getting any colour values from the 3d texture? [EDIT] Figured it out but can't self answer (new user): As soon as I posted this I figured it out, I'll put the answer up to help anyone else (it's not specifically a 3d texture issue, and i've also fallen afoul of it before, D'oh!). I didn't generate mipmaps for the texture, and the default magnification/minification filters weren't set to either GL_LINEAR, or GL_NEAREST. Boom! no textures. Same thing happens with 2d textures.

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• Of transactions and Mongo

  - by Nuri Halperin

  Originally posted on: http://geekswithblogs.net/nuri/archive/2014/05/20/of-transactions-and-mongo-again.aspxWhat's the first thing you hear about NoSQL databases? That they lose your data? That there's no transactions? No joins? No hope for "real" applications? Well, you *should* be wondering whether a certain of database is the right one for your job. But if you do so, you should be wondering that about "traditional" databases as well! In the spirit of exploration let's take a look at a common challenge: You are a bank. You have customers with accounts. Customer A wants to pay B. You want to allow that only if A can cover the amount being transferred. Let's looks at the problem without any context of any database engine in mind. What would you do? How would you ensure that the amount transfer is done "properly"? Would you prevent a "transaction" from taking place unless A can cover the amount? There are several options: Prevent any change to A's account while the transfer is taking place. That boils down to locking. Apply the change, and allow A's balance to go below zero. Charge person A some interest on the negative balance. Not friendly, but certainly a choice. Don't do either. Options 1 and 2 are difficult to attain in the NoSQL world. Mongo won't save you headaches here either. Option 3 looks a bit harsh. But here's where this can go: ledger. See, and account doesn't need to be represented by a single row in a table of all accounts with only the current balance on it. More often than not, accounting systems use ledgers. And entries in ledgers - as it turns out – don't actually get updated. Once a ledger entry is written, it is not removed or altered. A transaction is represented by an entry in the ledger stating and amount withdrawn from A's account and an entry in the ledger stating an addition of said amount to B's account. For sake of space-saving, that entry in the ledger can happen using one entry. Think {Timestamp, FromAccountId, ToAccountId, Amount}. The implication of the original question – "how do you enforce non-negative balance rule" then boils down to: Insert entry in ledger Run validation of recent entries Insert reverse entry to roll back transaction if validation failed. What is validation? Sum up the transactions that A's account has (all deposits and debits), and ensure the balance is positive. For sake of efficiency, one can roll up transactions and "close the book" on transactions with a pseudo entry stating balance as of midnight or something. This lets you avoid doing math on the fly on too many transactions. You simply run from the latest "approved balance" marker to date. But that's an optimization, and premature optimizations are the root of (some? most?) evil.. Back to some nagging questions though: "But mongo is only eventually consistent!" Well, yes, kind of. It's not actually true that Mongo has not transactions. It would be more descriptive to say that Mongo's transaction scope is a single document in a single collection. A write to a Mongo document happens completely or not at all. So although it is true that you can't update more than one documents "at the same time" under a "transaction" umbrella as an atomic update, it is NOT true that there' is no isolation. So a competition between two concurrent updates is completely coherent and the writes will be serialized. They will not scribble on the same document at the same time. In our case - in choosing a ledger approach - we're not even trying to "update" a document, we're simply adding a document to a collection. So there goes the "no transaction" issue. Now let's turn our attention to consistency. What you should know about mongo is that at any given moment, only on member of a replica set is writable. This means that the writable instance in a set of replicated instances always has "the truth". There could be a replication lag such that a reader going to one of the replicas still sees "old" state of a collection or document. But in our ledger case, things fall nicely into place: Run your validation against the writable instance. It is guaranteed to have a ledger either with (after) or without (before) the ledger entry got written. No funky states. Again, the ledger writing *adds* a document, so there's no inconsistent document state to be had either way. Next, we might worry about data loss. Here, mongo offers several write-concerns. Write-concern in Mongo is a mode that marshals how uptight you want the db engine to be about actually persisting a document write to disk before it reports to the application that it is "done". The most volatile, is to say you don't care. In that case, mongo would just accept your write command and say back "thanks" with no guarantee of persistence. If the server loses power at the wrong moment, it may have said "ok" but actually no written the data to disk. That's kind of bad. Don't do that with data you care about. It may be good for votes on a pole regarding how cute a furry animal is, but not so good for business. There are several other write-concerns varying from flushing the write to the disk of the writable instance, flushing to disk on several members of the replica set, a majority of the replica set or all of the members of a replica set. The former choice is the quickest, as no network coordination is required besides the main writable instance. The others impose extra network and time cost. Depending on your tolerance for latency and read-lag, you will face a choice of what works for you. It's really important to understand that no data loss occurs once a document is flushed to an instance. The record is on disk at that point. From that point on, backup strategies and disaster recovery are your worry, not loss of power to the writable machine. This scenario is not different from a relational database at that point. Where does this leave us? Oh, yes. Eventual consistency. By now, we ensured that the "source of truth" instance has the correct data, persisted and coherent. But because of lag, the app may have gone to the writable instance, performed the update and then gone to a replica and looked at the ledger there before the transaction replicated. Here are 2 options to deal with this. Similar to write concerns, mongo support read preferences. An app may choose to read only from the writable instance. This is not an awesome choice to make for every ready, because it just burdens the one instance, and doesn't make use of the other read-only servers. But this choice can be made on a query by query basis. So for the app that our person A is using, we can have person A issue the transfer command to B, and then if that same app is going to immediately as "are we there yet?" we'll query that same writable instance. But B and anyone else in the world can just chill and read from the read-only instance. They have no basis to expect that the ledger has just been written to. So as far as they know, the transaction hasn't happened until they see it appear later. We can further relax the demand by creating application UI that reacts to a write command with "thank you, we will post it shortly" instead of "thank you, we just did everything and here's the new balance". This is a very powerful thing. UI design for highly scalable systems can't insist that the all databases be locked just to paint an "all done" on screen. People understand. They were trained by many online businesses already that your placing of an order does not mean that your product is already outside your door waiting (yes, I know, large retailers are working on it... but were' not there yet). The second thing we can do, is add some artificial delay to a transaction's visibility on the ledger. The way that works is simply adding some logic such that the query against the ledger never nets a transaction for customers newer than say 15 minutes and who's validation flag is not set. This buys us time 2 ways: Replication can catch up to all instances by then, and validation rules can run and determine if this transaction should be "negated" with a compensating transaction. In case we do need to "roll back" the transaction, the backend system can place the timestamp of the compensating transaction at the exact same time or 1ms after the original one. Effectively, once A or B visits their ledger, both transactions would be visible and the overall balance "as of now" would reflect no change.  The 2 transactions (attempted/ reverted) would be visible , since we do actually account for the attempt. Hold on a second. There's a hole in the story: what if several transfers from A to some accounts are registered, and 2 independent validators attempt to compute the balance concurrently? Is there a chance that both would conclude non-sufficient-funds even though rolling back transaction 100 would free up enough for transaction 117 (some random later transaction)? Yes. there is that chance. But the integrity of the business rule is not compromised, since the prime rule is don't dispense money you don't have. To minimize or eliminate this scenario, we can also assign a single validation process per origin account. This may seem non-scalable, but it can easily be done as a "sharded" distribution. Say we have 11 validation threads (or processing nodes etc.). We divide the account number space such that each validator is exclusively responsible for a certain range of account numbers. Sounds cunningly similar to Mongo's sharding strategy, doesn't it? Each validator then works in isolation. More capacity needed? Chop the account space into more chunks. So where  are we now with the nagging questions? "No joins": Huh? What are those for? "No transactions": You mean no cross-collection and no cross-document transactions? Granted - but don't always need them either. "No hope for real applications": well... There are more issues and edge cases to slog through, I'm sure. But hopefully this gives you some ideas of how to solve common problems without distributed locking and relational databases. But then again, you can choose relational databases if they suit your problem.

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• C++: casting to void* and back

  - by MInner

  * ---Edit - now the whole sourse* When I debug it on the end, "get" and "value" have different values! Probably, I convert to void* and back to User the wrong way? #include <db_cxx.h> #include <stdio.h> struct User{ User(){} int name; int town; User(int a){}; inline int get_index(int a){ return town; } //for another stuff }; int main(){ try { DbEnv* env = new DbEnv(NULL); env->open("./", DB_CREATE | DB_INIT_MPOOL | DB_THREAD | DB_INIT_LOCK | DB_INIT_TXN | DB_RECOVER | DB_INIT_LOG, 0); Db* datab = new Db(env, 0); datab->open(NULL, "db.dbf", NULL, DB_BTREE, DB_CREATE | DB_AUTO_COMMIT, 0); Dbt key, value, get; char a[10] = "bbaaccd"; User u; u.name = 1; u.town = 34; key.set_data(a); key.set_size(strlen(a) + 1 ); value.set_data((void*)&u); value.set_size(sizeof(u)); get.set_flags(DB_DBT_MALLOC); DbTxn* txn; env->txn_begin(NULL, &txn, 0); datab->put(txn, &key, &value, 0); datab->get(txn, &key, &get, 0); txn->commit(0); User g; g = *((User*)&get); printf("%d", g.town); getchar(); return 0; }catch (DbException &e){ printf("%s", e.what()); getchar(); } solution create a kind of "serializator" what would convert all POD's into void* and then will unite these pieces PS Or I'd rewrite User into POD type and everything will be all right, I hope. Add It's strange, but... I cast a defenetly non-pod object to void* and back (it has std::string inside) and it's all right (without sending it to the db and back). How could it be? And after I cast and send 'trough' db defenetly pod object (no extra methods, all members are pod, it's a simple struct {int a; int b; ...}) I get back dirted one. What's wrong with my approach? Add about week after first 'add' Damn... I've compiled it ones, just for have a look at which kind of dirt it returnes, and oh! it's okay!... I can't ! ... AAh!.. Lord... A reasonable question (in 99.999 percent of situations right answer is 'my', but... here...) - whos is this fault? My or VSs?

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• can't get texture to work

  - by user583713

  It been a while since I use android opengl but for what ever reason I get a white squre box and not the texture I what on the screen. Oh I do not think this would matter but just in case I put a linerlayout view first then the surfaceview on but anyway Here my code: public class GameEngine { private float vertices[]; private float textureUV[]; private int[] textureId = new int[1]; private FloatBuffer vertextBuffer; private FloatBuffer textureBuffer; private short indices[] = {0,1,2,2,1,3}; private ShortBuffer indexBuffer; private float x, y, z; private float rot, rotX, rotY, rotZ; public GameEngine() { } public void setEngine(float x, float y, float vertices[]){ this.x = x; this.y = y; this.vertices = vertices; ByteBuffer vbb = ByteBuffer.allocateDirect(this.vertices.length * 4); vbb.order(ByteOrder.nativeOrder()); vertextBuffer = vbb.asFloatBuffer(); vertextBuffer.put(this.vertices); vertextBuffer.position(0); vertextBuffer.clear(); ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2); ibb.order(ByteOrder.nativeOrder()); indexBuffer = ibb.asShortBuffer(); indexBuffer.put(indices); indexBuffer.position(0); indexBuffer.clear(); } public void draw(GL10 gl){ gl.glLoadIdentity(); gl.glTranslatef(x, y, z); gl.glRotatef(rot, rotX, rotY, rotZ); gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId[0]); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vertextBuffer); gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer); gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, GL10.GL_UNSIGNED_SHORT, indexBuffer); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY); } public void LoadTexture(float textureUV[], GL10 gl, InputStream is) throws IOException{ this.textureUV = textureUV; ByteBuffer tbb = ByteBuffer.allocateDirect(this.textureUV.length * 4); tbb.order(ByteOrder.nativeOrder()); textureBuffer = tbb.asFloatBuffer(); textureBuffer.put(this.textureUV); textureBuffer.position(0); textureBuffer.clear(); Bitmap bitmap = null; try{ bitmap = BitmapFactory.decodeStream(is); }finally{ try{ is.close(); is = null; gl.glGenTextures(1, textureId,0); gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId[0]); gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST); gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR); //Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT); gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT); //Use the Android GLUtils to specify a two-dimensional texture image from our bitmap GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0); gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA); //Clean up gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId[0]); bitmap.recycle(); }catch(IOException e){ } } } public void setVector(float x, float y, float z){ this.x = x; this.y = y; this.z = z; } public void setRot(float rot, float x, float y, float z){ this.rot = rot; this.rotX = x; this.rotY = y; this.rotZ = z; } public float getZ(){ return z; } }

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• Suggestions on how to map from Domain (ORM) objects to Data Transfer Objects (DTO)

  - by FryHard

  The current system that I am working on makes use of Castle Activerecord to provide ORM (Object Relational Mapping) between the Domain objects and the database. This is all well and good and at most times actually works well! The problem comes about with Castle Activerecords support for asynchronous execution, well, more specifically the SessionScope that manages the session that objects belong to. Long story short, bad stuff happens! We are therefore looking for a way to easily convert (think automagically) from the Domain objects (who know that a DB exists and care) to the DTO object (who know nothing about the DB and care not for sessions, mapping attributes or all thing ORM). Does anyone have suggestions on doing this. For the start I am looking for a basic One to One mapping of object. Domain object Person will be mapped to say PersonDTO. I do not want to do this manually since it is a waste. Obviously reflection comes to mind, but I am hoping with some of the better IT knowledge floating around this site that "cooler" will be suggested. Oh, I am working in C#, the ORM objects as said before a mapped with Castle ActiveRecord. Example code: By @ajmastrean's request I have linked to an example that I have (badly) mocked together. The example has a capture form, capture form controller, domain objects, activerecord repository and an async helper. It is slightly big (3MB) because I included the ActiveRecored dll's needed to get it running. You will need to create a database called ActiveRecordAsync on your local machine or just change the .config file. Basic details of example: The Capture Form The capture form has a reference to the contoller private CompanyCaptureController MyController { get; set; } On initialise of the form it calls MyController.Load() private void InitForm () { MyController = new CompanyCaptureController(this); MyController.Load(); } This will return back to a method called LoadComplete() public void LoadCompleted (Company loadCompany) { _context.Post(delegate { CurrentItem = loadCompany; bindingSource.DataSource = CurrentItem; bindingSource.ResetCurrentItem(); //TOTO: This line will thow the exception since the session scope used to fetch loadCompany is now gone. grdEmployees.DataSource = loadCompany.Employees; }, null); } } this is where the "bad stuff" occurs, since we are using the child list of Company that is set as Lazy load. The Controller The controller has a Load method that was called from the form, it then calls the Asyc helper to asynchronously call the LoadCompany method and then return to the Capture form's LoadComplete method. public void Load () { new AsyncListLoad<Company>().BeginLoad(LoadCompany, Form.LoadCompleted); } The LoadCompany() method simply makes use of the Repository to find a know company. public Company LoadCompany() { return ActiveRecordRepository<Company>.Find(Setup.company.Identifier); } The rest of the example is rather generic, it has two domain classes which inherit from a base class, a setup file to instert some data and the repository to provide the ActiveRecordMediator abilities.

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• reloading page while an ajax request in progress gives empty response and status as zero

  - by Jayapal Chandran

  Hi, Browser is firefox 3.0.10 I am requesting a page using ajax. The response is in progress may be in readyState less than 4. In this mean time i am trying to reload the page. What happens is the request ends giving an empty response. I used alert to find what string has been given as response text. I assume that by this time the ready state 4 is reached. why it is empty string. when i alert the xmlhttpobject.status it displayed 0. when i alert the xmlhttpobject.statusText an exception occurs stating that NOT AVAILABLE. when i read in the document http://www.devx.com/webdev/Article/33024/0/page/2 it said for 3 and 4 status and statusText are available but when i tested only status is available but not satausText Here is a sample code. consider that i have requested a page and my callback function is as follows function cb(rt) { if(rt.readyState==4) { alert(rt.status); alert(rt.statusText); // which throws an exception } } and my server side script is as follows sleep(30); //flushing little drop down code besides these i noticed the following... assume again i am requesting the above script using ajax. now there will be an idle time till 30 seconds is over before that 30 seconds i press refresh. i got xmlhttpobject.status as 0 but still the browser did not reload the page untill that 30 seconds. WHY? so what is happening when i refresh a page before an ajax request is complete is the status value is set to zero and the ready state is set to 4 but the page still waits for the response from the server to end... what is happening... THE REASON FOR ME TO FACE SOME THING LIKE THIS IS AS FOLLOWS. when ever i do an ajax request ... if the process succeeded like inserting some thing or deleting something i popup a div stating that updated successfully and i will reload the page. but if there is any error then i do not reload the page instead i just alert that unable to process this request. what happens if the user reloads the page before any of this request is complete is i get an empty response which in my calculation is there is a server error. so i was debugging the ajax response to filter out that the connection has been interrupted because the user had pressed reload. so in this time i don't want to display unable to process this request when the user reloads the page before the request has been complete. oh... a long story. IT IS A LONG DESCRIPTION SO THAT I CAN MAKE EXPERTS UNDERSTAND MY DOUBT. so what i want form the above. any type of answer would clear my mind. or i would like to say all type of answers. EDIT: 19 dec. If i did not get any correct answer then i would delete this question and will rewrite with examples. else i will accept after experimenting.

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• web application with secured sections, sessions and related trouble

  - by spirytus

  I would like to create web application with admin/checkout sections being secured. Assuming I have SSL set up for subdomain.mydomain.com I would like to make sure that all that top-secret stuff ;) like checkout pages and admin section is transferred securely. Would it be ok to structure my application as below? subdomain.mydomain.com adminSectionFolder adminPage1.php adminPage2.php checkoutPagesFolder checkoutPage1.php checkoutPage2.php checkoutPage3.php homepage.php loginPage.php someOtherPage.php someNonSecureFolder nonSecurePage1.php nonSecurePage2.php nonSecurePage3.php imagesFolder image1.jpg image2.jpg image3.jpg Users would access my web application via http as there is no need for SSL for homepage and similar. Checkout/admin pages would have to be accessed via https though (that I would ensure via .htaccess redirects). I would also like to have login form on every page of the site, including non-secure pages. Now my questions are: if I have form on non-secure page e.g http://subdomain.mydomain.com/homepage.php and that form sends data to http://subdomain.mydomain.com/loginPage.php, is data being send encrypted as if it were sent from https://subdomain.mydomain.com/homepage.php? I do realize users will not see padlock, but browser still should encrypt it, is it right? If on secure page loginPage.php (or any other accessed via https for that instance) I created session, session ID would be assigned, and in case of my web app. something like username of the logged in user. Would I be able to access these session variable from http://subdomain.mydomain.com/homepage.php to for example display greeting message? If session ID is stored in cookies then it would be trouble I assume, but could someone clarify how it should be done? It seems important to have username and password send over SSL. Related to above question I think.. would it actually make any sense to have login secured via SSL so usenrame/password would be transferred securely, and then session ID being transferred with no SSL? I mean wouldnt it be the same really if someone caught username and password being transferred, or caught session ID? Please let me know if I make sense here cause it feels like I'm missing something important. EDIT: I came up with idea but again please let me know if that would work. Having above, so assuming that sharing session between http and https is as secure as login in user via plain http (not https), I guess on all non secure pages, like homepage etc. I could check if user is already logged in, and if so from php redirect to https version of same page. So user fills in login form from homepage.php, over ssl details are send to backend so probably https://.../homepage.php. Trying to access http://.../someOtherPage.php script would always check if session is created and if so redirect user to https version of this page so https://.../someOtherPage.php. Would that work? 4.To avoid browser popping message "this page contains non secure items..." my links to css, images and all assets, e.g. in case of http://subdomain.mydomain.com/checkoutPage1.php should be absolute so "/images/image1.jpg" or relative so "../images/image1.jpg"? I guess one of those would have to work :) wow that's long post, thanks for your patience if you got that far and any answers :) oh yeh and I use php/apache on shared hosting

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• how convert this c# cod to php

  - by user3694473

  I'm trying to convert this class from C# to php and i wante to convert this c# class to php ... how i can do it Thanks in advance hi I'm trying to convert this class from C# to php and i wante to convert this c# class to php ... how i can do it Thanks in advance public class CreateCode { public string SazBon(string MM) { string RET = ""; string[] ME = new string[25]; for (int i = 1; i < MM.Length; i += 2) { ME[i] = MM[i - 1].ToString(); } for (int j = 0; j < MM.Length; j += 2) { ME[j] = MM[j + 1].ToString(); } ME[20] = "1"; ME[21] = "OH"; ME[22] = "23"; ME[23] = "fXC"; ME[24] = "5"; ME[5] = ME[14]; ME[13] = ME[23]; ME[2] = ME[22]; ME[18] = ME[21]; ME[23] = ME[11]; ME[19] = ME[0]; foreach (string item in ME) { RET += item; } string BACK = Encrypt(RET, RET, 256); BACK = encryptString(BACK); return BACK; } string encryptString(string strToEncrypt) // md5 { UTF8Encoding ue = new UTF8Encoding(); byte[] bytes = ue.GetBytes(strToEncrypt); MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); byte[] hashBytes = md5.ComputeHash(bytes); // Bytes to string return System.Text.RegularExpressions.Regex.Replace (BitConverter.ToString(hashBytes), "-", "").ToLower(); } private byte[] Encrypt(byte[] clearData, byte[] Key, byte[] IV) { MemoryStream ms = new MemoryStream(); Rijndael alg = Rijndael.Create(); alg.Key = Key; alg.IV = IV; CryptoStream cs = new CryptoStream(ms, alg.CreateEncryptor(), CryptoStreamMode.Write); cs.Write(clearData, 0, clearData.Length); cs.Close(); byte[] encryptedData = ms.ToArray(); return encryptedData; } byte[] A; private string Encrypt(string Data, string Password, int Bits) { byte[] clearBytes = System.Text.Encoding.Unicode.GetBytes(Data); PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] { 0x00, 0x01, 0x02, 0x1C, 0x1D, 0x1E, 0x03, 0x04, 0x05, 0x0F, 0x20, 0x21, 0xAD, 0xAF, 0xA4 }); if (Bits == 128) { byte[] encryptedData = Encrypt(clearBytes, pdb.GetBytes(16), pdb.GetBytes(16)); return Convert.ToBase64String(encryptedData); } else if (Bits == 192) { byte[] encryptedData = Encrypt(clearBytes, pdb.GetBytes(24), pdb.GetBytes(16)); return Convert.ToBase64String(encryptedData); } else if (Bits == 256) { byte[] encryptedData = Encrypt(clearBytes, pdb.GetBytes(32), pdb.GetBytes(16)); return Convert.ToBase64String(encryptedData); } else { return string.Concat(Bits); } } // AES }

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• Recursively created linked lists with a class, C++

  - by Jon Brant

  I'm using C++ to recursively make a hexagonal grid (using a multiply linked list style). I've got it set up to create neighboring tiles easily, but because I'm doing it recursively, I can only really create all 6 neighbors for a given tile. Obviously, this is causing duplicate tiles to be created and I'm trying to get rid of them in some way. Because I'm using a class, checking for null pointers doesn't seem to work. It's either failing to convert from my Tile class to and int, or somehow converting it but not doing it properly. I'm explicitly setting all pointers to NULL upon creation, and when I check to see if it still is, it says it's not even though I never touched it since initialization. Is there a specific way I'm supposed to do this? I can't even traverse the grid without NULLs of some kind Here's some of my relevant code. Yes, I know it's embarassing. Tile class header: class Tile { public: Tile(void); Tile(char *Filename); ~Tile(void); void show(void); bool LoadGLTextures(); void makeDisplayList(); void BindTexture(); void setFilename(char *newName); char Filename[100]; GLuint texture[2]; GLuint displayList; Tile *neighbor[6]; float xPos, yPos,zPos; };` Tile Initialization: Tile::Tile(void) { xPos=0.0f; yPos=0.0f; zPos=0.0f; glEnable(GL_DEPTH_TEST); strcpy(Filename, strcpy(Filename, "Data/BlueTile.bmp")); if(!BuildTexture(Filename, texture[0]))MessageBox(NULL,"Texture failed to load!","Crap!",MB_OK|MB_ICONASTERISK); for(int x=0;x<6;x++) { neighbor[x]=NULL; } } Creation of neighboring tiles: void MakeNeighbors(Tile *InputTile, int stacks) { for(int x=0;x<6;x++) { InputTile->neighbor[x]=new Tile();InputTile->neighbor[x]->xPos=0.0f;InputTile->neighbor[x]->yPos=0.0f;InputTile->zPos=float(stacks); } if(stacks) { for(int x=0;x<6;x++)MakeNeighbors(InputTile->neighbor[x],stacks-1); } } And finally, traversing the grid: void TraverseGrid(Tile *inputTile) { Tile *temp; for(int x=0;x<6;x++) if(inputTile->neighbor[x]) { temp=inputTile->neighbor[x]; temp->xPos=0.0f; TraverseGrid(temp); //MessageBox(NULL,"Not Null!","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); } } The key line is "if(inputTile-neighbor[x])" and whether I make it "if(inputTile-neighbor[x]==NULL)" or whatever I do, it just isn't handling it properly. Oh and I'm also aware that I haven't set up the list fully. It's only one direction now.

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• Stumbling Through: Visual Studio 2010 (Part IV)

  So finally we get to the fun part the fruits of all of our middle-tier/back end labors of generating classes to interface with an XML data source that the previous posts were about can now be presented quickly and easily to an end user.  I think.  Well see.  Well be using a WPF window to display all of our various MFL information that weve collected in the two XML files, and well provide a means of adding, updating and deleting each of these entities using as little code as possible.  Additionally, I would like to dig into the performance of this solution as well as the flexibility of it if were were to modify the underlying XML schema.  So first things first, lets create a WPF project and include our xml data in a data folder within.  On the main window, well drag out the following controls: A combo box to contain all of the teams A list box to show the players of the selected team, along with add/delete player buttons A text box tied to the selected players name, with a save button to save any changes made to the player name A combo box of all the available positions, tied to the currently selected players position A data grid tied to the statistics of the currently selected player, with add/delete statistic buttons This monstrosity of a form and its associated project will look like this (dont forget to reference the DataFoundation project from the Presentation project): To get to the visual data binding, as we learned in a previous post, you have to first make sure the project containing your bindable classes is compiled.  Do so, and then open the Data Sources pane to add a reference to the Teams and Positions classes in the DataFoundation project: Why only Team and Position?  Well, we will get to Players from Teams, and Statistics from Players so no need to make an interface for them as well see in a second.  As for Positions, well need a way to bind the dropdown to ALL positions they dont appear underneath any of the other classes so we need to reference it directly.  After adding these guys, expand every node in your Data Sources pane and see how the Team node allows you to drill into Players and then Statistics.  This is why there was no need to bring in a reference to those classes for the UI we are designing: Now for the seriously hard work of binding all of our controls to the correct data sources.  Drag the following items from the Data Sources pane to the specified control on the window design canvas: Team.Name > Teams combo box Team.Players.Name > Players list box Team.Players.Name > Player name text box Team.Players.Statistics > Statistics data grid Position.Name > Positions combo box That is it!  Really?  Well, no, not really there is one caveat here in that the Positions combo box is not bound the selected players position.  To do so, we will apply a binding to the position combo boxs SelectedValue to point to the current players PositionId value: That should do the trick now, all we need to worry about is loading the actual data.  Sadly, it appears as if we will need to drop to code in order to invoke our IO methods to load all teams and positions.  At least Visual Studio kindly created the stubs for us to do so, ultimately the code should look like this: Note the weirdness with the InitializeDataFiles call that is my current means of telling an IO where to load the data for each of the entities.  I havent thought of a more intuitive way than that yet, but do note that all data is loaded from Teams.xml besides for positions, which is loaded from Lookups.xml.   I think that may be all we need to do to at least load all of the data, lets run it and see: Yay!  All of our glorious data is being displayed!  Er, wait, whats up with the position dropdown?  Why is it red?  Lets select the RB and see if everything updates: Crap, the position didnt update to reflect the selected player, but everything else did.  Where did we go wrong in binding the position to the selected player?  Thinking about it a bit and comparing it to how traditional data binding works, I realize that we never set the value member (or some similar property) to tell the control to join the Id of the source (positions) to the position Id of the player.  I dont see a similar property to that on the combo box control, but I do see a property named SelectedValuePath that might be it, so I set it to Id and run the app again: Hey, all right!  No red box around the positions combo box.  Unfortunately, selecting the RB does not update the dropdown to point to Runningback.  Hmmm.  Now what could it be?  Maybe the problem is that we are loading teams before we are loading positions, so when it binds position Id, all of the positions arent loaded yet.  I went to the code behind and switched things so position loads first and no dice.  Same result when I run.  Why?  WHY?  Ok, ok, calm down, take a deep breath.  Get something with caffeine or sugar (preferably both) and think rationally. Ok, gigantic chocolate chip cookie and a mountain dew chaser have never let me down in the past, so dont fail me now!  Ah ha!  of course!  I didnt even have to finish the mountain dew and I think Ive got it:  Data Context.  By default, when setting on the selected value binding for the dropdown, the data context was list_team.  I dont even know what the heck list_team is, we want it to be bound to our team players view source resource instead, like this: Running it now and selecting the various players: Done and done.  Everything read and bound, thank you caffeine and sugar!  Oh, and thank you Visual Studio 2010.  Lets wire up some of those buttons now There has got to be a better way to do this, but it works for now.  What the add player button does is add a new player object to the currently selected team.  Unfortunately, I couldnt get the new object to automatically show up in the players list (something about not using an observable collection gotta look into this) so I just save the change immediately and reload the screen.  Terrible, but it works: Lets go after something easier:  The save button.  By default, as we type in new text for the players name, it is showing up in the list box as updated.  Cool!  Why couldnt my add new player logic do that?  Anyway, the save button should be as simple as invoking MFL.IO.Save for the selected player, like this: MFL.IO.Save((MFL.Player)lbTeamPlayers.SelectedItem, true); Surprisingly, that worked on the first try.  Lets see if we get as lucky with the Delete player button: MFL.IO.Delete((MFL.Player)lbTeamPlayers.SelectedItem); Refresh(); Note the use of the Refresh method again I cant seem to figure out why updates to the underlying data source are immediately reflected, but adds and deletes are not.  That is a problem for another day, and again my hunch is that I should be binding to something more complex than IEnumerable (like observable collection). Now that an example of the basic CRUD methods are wired up, I want to quickly investigate the performance of this beast.  Im going to make a special button to add 30 teams, each with 50 players and 10 seasons worth of stats.  If my math is right, that will end up with 15000 rows of data, a pretty hefty amount for an XML file.  The save of all this new data took a little over a minute, but that is acceptable because we wouldnt typically be saving batches of 15k records, and the resulting XML file size is a little over a megabyte.  Not huge, but big enough to see some read performance numbers or so I thought.  It reads this file and renders the first team in under a second.  That is unbelievable, but we are lazy loading and the file really wasnt that big.  I will increase it to 50 teams with 100 players and 20 seasons each - 100,000 rows.  It took a year and a half to save all of that data, and resulted in an 8 megabyte file.  Seriously, if you are loading XML files this large, get a freaking database!  Despite this, it STILL takes under a second to load and render the first team, which is interesting mostly because I thought that it was loading that entire 8 MB XML file behind the scenes.  I have to say that I am quite impressed with the performance of the LINQ to XML approach, particularly since I took no efforts to optimize any of this code and was fairly new to the concept from the start.  There might be some merit to this little project after all Look out SQL Server and Oracle, use XML files instead!  Next up, I am going to completely pull the rug out from under the UI and change a number of entities in our model.  How well will the code be regenerated?  How much effort will be required to tie things back together in the UI?Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Defend PHP; convince me it isn't horrible

  - by Jason L

  I made a tongue-in-cheek comment in another question thread calling PHP a terrible language and it got down-voted like crazy. Apparently there are lots of people here who love PHP. So I'm genuinely curious. What am I missing? What makes PHP a good language? Here are my reasons for disliking it: PHP has inconsistent naming of built-in and library functions. Predictable naming patterns are important in any design. PHP has inconsistent parameter ordering of built-in functions, eg array_map vs. array_filter which is annoying in the simple cases and raises all sorts of unexpected behaviour or worse. The PHP developers constantly deprecate built-in functions and lower-level functionality. A good example is when they deprecated pass-by-reference for functions. This created a nightmare for anyone doing, say, function callbacks. A lack of consideration in redesign. The above deprecation eliminated the ability to, in many cases, provide default keyword values for functions. They fixed this in PHP 5, but they deprecated the pass-by-reference in PHP 4! Poor execution of name spaces (formerly no name spaces at all). Now that name spaces exist, what do we use as the dereference character? Backslash! The character used universally for escaping, even in PHP! Overly-broad implicit type conversion leads to bugs. I have no problem with implicit conversions of, say, float to integer or back again. But PHP (last I checked) will happily attempt to magically convert an array to an integer. Poor recursion performance. Recursion is a fundamentally important tool for writing in any language; it can make complex algorithms far simpler. Poor support is inexcusable. Functions are case insensitive. I have no idea what they were thinking on this one. A programming language is a way to specify behavior to both a computer and a reader of the code without ambiguity. Case insensitivity introduces much ambiguity. PHP encourages (practically requires) a coupling of processing with presentation. Yes, you can write PHP that doesn't do so, but it's actually easier to write code in the incorrect (from a sound design perspective) manner. PHP performance is abysmal without caching. Does anyone sell a commercial caching product for PHP? Oh, look, the designers of PHP do. Worst of all, PHP convinces people that designing web applications is easy. And it does indeed make much of the effort involved much easier. But the fact is, designing a web application that is both secure and efficient is a very difficult task. By convincing so many to take up programming, PHP has taught an entire subgroup of programmers bad habits and bad design. It's given them access to capabilities that they lack the understanding to use safely. This has led to PHP's reputation as being insecure. (However, I will readily admit that PHP is no more or less secure than any other web programming language.) What is it that I'm missing about PHP? I'm seeing an organically-grown, poorly-managed mess of a language that's spawning poor programmers. So convince me otherwise!

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• Accessing Layout Items from inside Widget AppWidgetProvider

  - by cam4mav

  I am starting to go insane trying to figure this out. It seems like it should be very easy, I'm starting to wonder if it's possible. What I am trying to do is create a home screen widget, that only contains an ImageButton. When it is pressed, the idea is to change some setting (like the wi-fi toggle) and then change the Buttons image. I have the ImageButton declared like this in my main.xml <ImageButton android:id="@+id/buttonOne" android:src="@drawable/button_normal_ringer" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" /> my AppWidgetProvider class, named ButtonWidget * note that the RemoteViews class is a locally stored variable. this allowed me to get access to the RViews layout elements... or so I thought. @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { remoteViews = new RemoteViews(context.getPackageName(), R.layout.main); Intent active = new Intent(context, ButtonWidget.class); active.setAction(VIBRATE_UPDATE); active.putExtra("msg","TESTING"); PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context, 0, active, 0); remoteViews.setOnClickPendingIntent(R.id.buttonOne, actionPendingIntent); appWidgetManager.updateAppWidget(appWidgetIds, remoteViews); } @Override public void onReceive(Context context, Intent intent) { // v1.5 fix that doesn't call onDelete Action final String action = intent.getAction(); Log.d("onReceive",action); if (AppWidgetManager.ACTION_APPWIDGET_DELETED.equals(action)) { final int appWidgetId = intent.getExtras().getInt( AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); if (appWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID) { this.onDeleted(context, new int[] { appWidgetId }); } } else { // check, if our Action was called if (intent.getAction().equals(VIBRATE_UPDATE)) { String msg = "null"; try { msg = intent.getStringExtra("msg"); } catch (NullPointerException e) { Log.e("Error", "msg = null"); } Log.d("onReceive",msg); if(remoteViews != null){ Log.d("onReceive",""+remoteViews.getLayoutId()); remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer); Log.d("onReceive", "tried to switch"); } else{ Log.d("F!", "--naughty language used here!!!--"); } } super.onReceive(context, intent); } } so, I've been testing this and the onReceive method works great, I'm able to send notifications and all sorts of stuff (removed from code for ease of reading) the one thing I can't do is change any properties of the view elements. To try and fix this, I made RemoteViews a local and static private variable. Using log's I was able to see that When multiple instances of the app are on screen, they all refer to the one instance of RemoteViews. perfect for what I'm trying to do The trouble is in trying to change the image of the ImageButton. I can do this from within the onUpdate method using this. remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer); that doesn't do me any good though once the widget is created. For some reason, even though its inside the same class, being inside the onReceive method makes that line not work. That line used to throw a Null pointer as a matter of fact, until I changed the variable to static. now it passes the null test, refers to the same layoutId as it did at the start, reads the line, but it does nothing. Its like the code isn't even there, just keeps chugging along. SO...... Is there any way to modify layout elements from within a widget after the widget has been created!? I want to do this based on the environment, not with a configuration activity launch. I've been looking at various questions and this seems to be an issue that really hasn't been solved, such as link text and link text oh and for anyone who finds this and wants a good starting tutorial for widgets, this is easy to follow (though a bit old, it gets you comfortable with widgets) .pdf link text hopefully someone can help here. I kinda have the feeling that this is illegal and there is a different way to go about this. I would LOVE to be told another approach!!!! Thanks

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• Doing XML extracts with XSLT without having to read the whole DOM tree into memory?

  - by Thorbjørn Ravn Andersen

  I have a situation where I want to extract some information from some very large but regular XML files (just had to do it with a 500 Mb file), and where XSLT would be perfect. Unfortunately those XSLT implementations I am aware of (except the most expensive version of Saxon) does not support only having the necessary part of the DOM read in but reads in the whole tree. This cause the computer to swap to death. The XPath in question is //m/e[contains(.,'foobar') so it is essentially just a grep. Is there an XSLT implementation which can do this? Or an XSLT implementation which given suitable "advice" can do this trick of pruning away the parts in memory which will not be needed again? I'd prefer a Java implementation but both Windows and Linux are viable native platforms. EDIT: The input XML looks like: <log> <!-- Fri Jun 26 12:09:27 CEST 2009 --> <e h='12:09:27,284' l='org.apache.catalina.session.ManagerBase' z='1246010967284' t='ContainerBackgroundProcessor[StandardEngine[Catalina]]' v='10000'> <m>Registering Catalina:type=Manager,path=/axsWHSweb-20090626,host=localhost</m></e> <e h='12:09:27,284' l='org.apache.catalina.session.ManagerBase' z='1246010967284' t='ContainerBackgroundProcessor[StandardEngine[Catalina]]' v='10000'> <m>Force random number initialization starting</m></e> <e h='12:09:27,284' l='org.apache.catalina.session.ManagerBase' z='1246010967284' t='ContainerBackgroundProcessor[StandardEngine[Catalina]]' v='10000'> <m>Getting message digest component for algorithm MD5</m></e> <e h='12:09:27,284' l='org.apache.catalina.session.ManagerBase' z='1246010967284' t='ContainerBackgroundProcessor[StandardEngine[Catalina]]' v='10000'> <m>Completed getting message digest component</m></e> <e h='12:09:27,284' l='org.apache.catalina.session.ManagerBase' z='1246010967284' t='ContainerBackgroundProcessor[StandardEngine[Catalina]]' v='10000'> <m>getDigest() 0</m></e> ...... </log> Essentialy I want to select some m-nodes (and I know the XPath is wrong for that, it was just a quick hack), but maintain the XML layout. EDIT: It appears that STX may be what I am looking for (I can live with another transformation language), and that Joost is an implementation hereof. Any experiences? EDIT: I found that Saxon 6.5.4 with -Xmx1500m could load my XML, so this allowed me to use my XPaths right now. This is just a lucky stroke so I'd still like to solve this generically - this means scriptable which in turn means no handcrafted Java filtering first. EDIT: Oh, by the way. This is a log file very similar to what is generated by the log4j XMLLayout. The reason for XML is to be able to do exactly this, namely do queries on the log. This is the initial try, hence the simple question. Later I'd like to be able to ask more complex questions - therefore I'd like the query language to be able to handle the input file.

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• Form inside a hidden div has no values on post

  - by Mick

  I have a html form that posts to a new page on submit. If required a user can click a button to make a small table visible in a div box. this adds more text input fields to my form. The problem is, regardless of the div box being hidden or visible none of the additional fields data is sent when the form is posted . the div box code function quotevisi() { document.getElementById("quote").style.visibility = "visible"; tdat = "" ; tdat += "<h2 align='center' >Client Quotation </h2>" ; tdat += "<table align='center'cellpadding='1' width='690px'><tr>" tdat += "<td ></td><td>Additional 1</td>" ; tdat += "<td ><label><textarea id='line1' cols='50' rows='1'>" tdat += "</textarea></label></td></tr>" tdat += "<td ></td><td >Additional 2 </td>" ; tdat += "<td ><label><textarea id='line2' name='line2' cols='50' rows='1'>" tdat += "</textarea></label></td></tr>" tdat += "<td ></td><td >Additional 3 </td>" ; tdat += "<td ><label><textarea id='line3' name='line3' cols='50' rows='1'>" tdat += "</textarea></label></td></tr>" tdat += "<td ></td><td >Special Instructions</td>" ; tdat += "<td ><label><textarea id='special' name='special' cols='50' rows='1'>" tdat += "</textarea></label></td></tr>" tdat += "<td ></td><td ></td> <td>" ; tdat += "<input type='button' value='View Quote' onclick='view_quote()' /> " tdat += "<input type='button' value='Close' onclick='closequote()' /> " tdat += "<td ></td> " ; tdat += "</table> " // display in the quote div (style sheet) document.getElementById('quote').innerHTML= tdat } The form is a bit big to but the button for the hidden field is this <td ><input class="buttn" type="button" value="Extra Quote details " onclick="quotevisi();" /> </td> I would of thought that all this information would go with the form on post . But it doesent. Oh finally the div box code is placed after this line <form style='background-color:ccc' id='form1' name='form1' method='post' action='process.php' > Any help or thoughts would be much appreciated thanks Mick

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• Using AsyncTask, but experiencing unexpected behaviour

  - by capcom

  Please refer to the following code which continuously calls a new AsyncTask. The purpose of the AsyncTask is to make an HTTP request, and update the string result. package room.temperature; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.concurrent.ExecutionException; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import android.app.Activity; import android.os.AsyncTask; import android.os.Bundle; import android.util.Log; import android.widget.TextView; public class RoomTemperatureActivity extends Activity { String result = null; StringBuilder sb=null; TextView TemperatureText, DateText; ArrayList<NameValuePair> nameValuePairs; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); TemperatureText = (TextView) findViewById(R.id.temperature); DateText = (TextView) findViewById(R.id.date); nameValuePairs = new ArrayList<NameValuePair>(); for (int i = 0; i < 10; i++) { RefreshValuesTask task = new RefreshValuesTask(); task.execute(""); } } // The definition of our task class private class RefreshValuesTask extends AsyncTask<String, Integer, String> { @Override protected void onPreExecute() { super.onPreExecute(); } @Override protected String doInBackground(String... params) { InputStream is = null; try { HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost("http://mywebsite.com/roomtemp/tempscript.php"); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); is = entity.getContent(); } catch(Exception e) { Log.e("log_tag", "Error in http connection" + e.toString()); } try { BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8); sb = new StringBuilder(); sb.append(reader.readLine()); is.close(); result=sb.toString(); } catch(Exception e) { Log.e("log_tag", "Error converting result " + e.toString()); } return result; } @Override protected void onProgressUpdate(Integer... values) { super.onProgressUpdate(values); } @Override protected void onPostExecute(String result) { super.onPostExecute(result); //System.out.println(result); setValues(result); } } public void setValues(String resultValue) { System.out.println(resultValue); String[] values = resultValue.split("&"); TemperatureText.setText(values[0]); DateText.setText(values[1]); } } The problem I am experiencing relates to the AsyncTask in some way or the function setValues(), but I am not sure how. Essentially, I want each call to the AsyncTask to run, eventually in an infinite while loop, and update the TextView fields as I have attempted in setValues. I have tried since yesterday after asking a question which led to this code, for reference. Oh yes, I did try using the AsyncTask get() method, but that didn't work either as I found out that it is actually a synchronous call, and renders the whole point of AsyncTask useless.

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• ?????Exadata????

  - by Liu Maclean(???)

  ??check Exadata Image & OS versions , GI & DB patches sundiag exacheck cellserv ==> imageinfo dbhost ==> /usr/local/bin/imagehistory Also check the version of the switch. Login to Switch and execute the following command [root@myswitch-1 sbin]# version [root@dmorlsw-ib2 sbin]# cd /usr/local/bin [root@dmorlsw-ib2 bin]# ls -lrt version -rwxr-xr-x 1 root root 20356 Apr 4 2011 version Output will look as below. [root@dmorlsw-ib2 ~]# version SUN DCS 36p version: 1.3.3-2 Build time: Apr 4 2011 11:15:19 SP board info: Manufacturing Date: 2009.05.05 Serial Number: "NCD3X0178" Hardware Revision: 0x0006 Firmware Revision: 0x0102 BIOS version: NOW1R112 BIOS date: 04/24/2009 ib8# cat /sys/class/infiniband/is4_0/fw_ver 7.2.300 ib8 # cat /sys/class/dmi/id/bios_version NOW1R112 ib8 # nm2version NM2-36p version: 1.0.1-1 Build time: Sep 14 2009 12:52:51 ComExpress info: Manufacturing Date: 2009.08.19 Serial Number: Hardware Revision: 0x0006 Firmware Revision: 0x0102 { case `uname` in Linux ) ILOM="/usr/bin/ipmitool sunoem cli" ;; SunOS ) ILOM="/opt/ipmitool/bin/ipmitool sunoem cli" ;; esac ; ImageInfo="/opt/oracle.cellos/imageinfo" ; uname -srm ; head -1 /etc/*release ; uptime | cut -d, -f1 ; $ILOM "show /SP system_description system_identifier" | grep = ; $ImageInfo -activated -node -status -ver | grep -v ^$ ; } | tee /tmp/ExaInfo.log $GRID_HOME/OPatch/opatch lsinv -all -oh $GRID_HOME | tee /tmp/OPatchInv.log $ORACLE_HOME/OPatch/opatch lsinv -all | tee -a /tmp/OPatchInv.log cat /tmp/ExaInfo.log Linux 2.6.18-128.1.16.0.1.el5 x86_64 ==> /etc/enterprise-release <== Enterprise Linux Enterprise Linux Server release 5.3 (Carthage) ==> /etc/redhat-release <== Enterprise Linux Enterprise Linux Server release 5.3 (Carthage) 20:37:56 up 458 days system_description = SUN FIRE X4170 SERVER, ILOM v3.0.6.10.b, r52264 system_identifier = Sun Oracle Database Machine Active image version: 11.2.1.2.3 Active image activated: XXXX-XX-XX 12:27:12 +0800 Active image status: success Active node type: COMPUTE Inactive image version: undefined FileName: OPatchInv.log ---------------- ... Oracle Home       : /u01/app/11.2.0/grid Central Inventory : /u01/app/oraInventory   from           : /etc/oraInst.loc OPatch version    : 11.2.0.1.2 OUI version       : 11.2.0.1.0 OUI location      : /u01/app/11.2.0/grid/oui ... -------------------------------------------------------------------------------- List of Oracle Homes:   Name                                       Location   Ora11g_gridinfrahome1         /u01/app/11.2.0/grid   OraDb11g_home1                  /u01/app/oracle/product/11.2.0/dbhome_1 -------------------------------------------------------------------------------- Installed Top-level Products (1): Oracle Grid Infrastructure                                           11.2.0.1.0 ... Interim patches (2) : Patch  9524394      : applied on Thu Jun 03 20:46:05 CST 2010 ... {TRACKING BUG FOR 11.2.0.1 DB MACHINE BUNDLE PATCH 3} Patch  9455587      : applied on Fri Apr 02 18:27:47 CST 2010 ... {MERGE REQUEST ON TOP OF 11.2.0.1.0 FOR BUGS 8483425 8667622 8702731 8730804} Rac system comprising of multiple nodes  Local node = dbserv01  Remote node = dbserv02  Remote node = dbserv03  Remote node = dbserv04 -------------------------------------------------------------------------------- OPatch succeeded. ... Oracle Home       : /u01/app/oracle/product/11.2.0/dbhome_1 ... Oracle Database 11g                                                  11.2.0.1.0 ... Interim patches (5) : Patch  8888434      : applied on Sat Jan 08 00:27:33 CST 2011 ... {AIX-ASM-CF: LMHB TERMINATE INSTANCE WHEN OFFLINE ONE FAILGROUP IN ASM DG} Patch  8730312      : applied on Thu Jun 03 21:30:03 CST 2010 ... {FWD MERGE FOR BASE BUG 8715387 FOR 12G} Patch  9502717      : applied on Thu Jun 03 21:25:54 CST 2010 ... {LMS HIT ORA-600 [KJBLDRMNEXTPKEY:SEEN] AND CRASHED THE INSTANCE} { + same 2 as GI above} ?? cell server Cache Policy cell08# MegaCli64 -LDInfo -Lall -aALL | grep 'Current Cache Policy' Current Cache Policy: WriteThrough, ReadAheadNone, Direct, No Write Cache if Bad BBU cell09# MegaCli64 -LDInfo -Lall -aALL | grep 'Current Cache Policy' Current Cache Policy: WriteBack, ReadAheadNone, Direct, No Write Cache if Bad BBU Default Cache Policy: WriteBack, ReadAheadNone, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAheadNone, Direct, No Write Cache if Bad BBU Cache policy is in WB Would recommend proactive  battery repalcement. Example : a. /opt/MegaRAID/MegaCli/MegaCli64 -LDGetProp  -Cache -LALL -aALL ####( Will list the cache policy) b. /opt/MegaRAID/MegaCli/MegaCli64 -LDSetProp  -WB  -LALL -aALL ####( Will try to change teh policy from xx to WB)     So policy Change to WB will not come into effect immediately     Set Write Policy to WriteBack on Adapter 0, VD 0 (target id: 0) success     Battery capacity is below the threshold value ??cell BBU??????: cell08# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd -GetBbuStatus -a0 BBU status for Adapter: 0 BatteryType: iBBU Voltage: 4061 mV Current: 0 mA Temperature: 36 C BBU Firmware Status: Charging Status : None Voltage : OK Temperature : OK Learn Cycle Requested : No Learn Cycle Active : No Learn Cycle Status : OK Learn Cycle Timeout : No I2c Errors Detected : No Battery Pack Missing : No Battery Replacement required : No Remaining Capacity Low : Yes Periodic Learn Required : No Battery state: GasGuageStatus: Fully Discharged : No Fully Charged : Yes Discharging : Yes Initialized : Yes Remaining Time Alarm : No Remaining Capacity Alarm: No Discharge Terminated : No Over Temperature : No Charging Terminated : No Over Charged : No Relative State of Charge: 99 % Charger System State: 49168 Charger System Ctrl: 0 Charging current: 0 mA Absolute state of charge: 21 % Max Error: 2 % Exit Code: 0x00 ????BBU ??: dcli -g ~/cell_group -l root -t '{ uname -srm ; head -1 /etc/*release ; uptime | cut -d, -f1 ; imagehistory ; ipmitool sunoem cli "show /SP system_description system_identifier" | grep = ; ipmitool sunoem cli "show /SP/policy FLASH_ACCELERATOR_CARD_INSTALLED /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd -GetBbuStatus -a0 | egrep -i 'BBU|Battery|Charge:|Fully|Low|Learn' ; }' | tee /tmp/ExaInfo.log Target cells: ['cellserv01', 'cellserv02', 'cellserv03', 'cellserv04', 'cellserv05', 'cellserv06', 'cellserv07'] cellserv01: Linux 2.6.18-128.1.16.0.1.el5 x86_64 cellserv01: ==> /etc/enterprise-release <== cellserv01: Enterprise Linux Enterprise Linux Server release 5.3 (Carthage) cellserv01: cellserv01: ==> /etc/redhat-release <== cellserv01: Enterprise Linux Enterprise Linux Server release 5.3 (Carthage) cellserv01: 01:17:39 up 635 days cellserv01: Version : 11.2.1.2.1 cellserv01: Image activation date : 2011-03-25 11:59:34 -0800 cellserv01: Imaging mode : fresh cellserv01: Imaging status : success cellserv01: cellserv01: Version : 11.2.1.2.3 cellserv01: Image activation date : 2011-04-13 12:15:46 +0800 cellserv01: Imaging mode : patch cellserv01: Imaging status : success cellserv01: cellserv01: Version : 11.2.1.2.6 cellserv01: Image activation date : 2011-05-27 23:08:22 +0800 cellserv01: Imaging mode : patch cellserv01: Imaging status : success cellserv01: cellserv01: system_description = SUN FIRE X4275 SERVER, ILOM v3.0.6.10.b, r52264 cellserv01: system_identifier = Sun Oracle Database Machine cellserv01: Connected. Use ^D to exit. cellserv01: -> show /SP/policy FLASH_ACCELERATOR_CARD_INSTALLED cellserv01: show: No matching properties found. cellserv01: cellserv01: -> Session closed cellserv01: Disconnected cellserv01: BBU status for Adapter: 0 cellserv01: BatteryType: iBBU cellserv01: BBU Firmware Status: cellserv01: Learn Cycle Requested : No cellserv01: Learn Cycle Active : No cellserv01: Learn Cycle Status : OK cellserv01: Learn Cycle Timeout : No cellserv01: Battery Pack Missing : No cellserv01: Battery Replacement required : No cellserv01: Remaining Capacity Low : Yes cellserv01: Periodic Learn Required : No cellserv01: Battery state: cellserv01: Fully Discharged : No cellserv01: Fully Charged : Yes cellserv01: Relative State of Charge: 99 % cellserv01: Absolute state of charge: 21 % dcli -l root -g /root/all_group '/opt/MegaRAID/MegAaCli/MegaCli64 -AdpBbuCmd -a0' > BBU.out check ipmi: dcli -g ~/cell_group -l root -t '{ > ipmitool sunoem cli "show /SP/policy FLASH_ACCELERATOR_CARD_INSTALLED" | grep = ; MegaCli64 -LDInfo -Lall -aALL | grep 'Current Cache Policy' ; }' | tee /tmp/ExaCells.log

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• SQL Monitor’s data repository: Alerts

  - by Chris Lambrou

  In my previous post, I introduced the SQL Monitor data repository, and described how the monitored objects are stored in a hierarchy in the data schema, in a series of tables with a _Keys suffix. In this post I had planned to describe how the actual data for the monitored objects is stored in corresponding tables with _StableSamples and _UnstableSamples suffixes. However, I’m going to postpone that until my next post, as I’ve had a request from a SQL Monitor user to explain how alerts are stored. In the SQL Monitor data repository, alerts are stored in tables belonging to the alert schema, which contains the following five tables: alert.Alert alert.Alert_Cleared alert.Alert_Comment alert.Alert_Severity alert.Alert_Type In this post, I’m only going to cover the alert.Alert and alert.Alert_Type tables. I may cover the other three tables in a later post. The most important table in this schema is alert.Alert, as each row in this table corresponds to a single alert. So let’s have a look at it. SELECT TOP 100 AlertId, AlertType, TargetObject, [Read], SubType FROM alert.Alert ORDER BY AlertId DESC;  AlertIdAlertTypeTargetObjectReadSubType 165550397:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,9:SqlServer,1,4:Name,s0:,10 265549387:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,7:Machine,1,4:Name,s0:,10 365548187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 465547157:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 565546147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 665545187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 765544157:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 865543147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 965542187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 1065541147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 11…     So what are we seeing here, then? Well, AlertId is an auto-incrementing identity column, so ORDER BY AlertId DESC ensures that we see the most recent alerts first. AlertType indicates the type of each alert, such as Job failed (6), Backup overdue (14) or Long-running query (12). The TargetObject column indicates which monitored object the alert is associated with. The Read column acts as a flag to indicate whether or not the alert has been read. And finally the SubType column is used in the case of a Custom metric (40) alert, to indicate which custom metric the alert pertains to. Okay, now lets look at some of those columns in more detail. The AlertType column is an easy one to start with, and it brings use nicely to the next table, data.Alert_Type. Let’s have a look at what’s in this table: SELECT AlertType, Event, Monitoring, Name, Description FROM alert.Alert_Type ORDER BY AlertType;  AlertTypeEventMonitoringNameDescription 1100Processor utilizationProcessor utilization (CPU) on a host machine stays above a threshold percentage for longer than a specified duration 2210SQL Server error log entryAn error is written to the SQL Server error log with a severity level above a specified value. 3310Cluster failoverThe active cluster node fails, causing the SQL Server instance to switch nodes. 4410DeadlockSQL deadlock occurs. 5500Processor under-utilizationProcessor utilization (CPU) on a host machine remains below a threshold percentage for longer than a specified duration 6610Job failedA job does not complete successfully (the job returns an error code). 7700Machine unreachableHost machine (Windows server) cannot be contacted on the network. 8800SQL Server instance unreachableThe SQL Server instance is not running or cannot be contacted on the network. 9900Disk spaceDisk space used on a logical disk drive is above a defined threshold for longer than a specified duration. 101000Physical memoryPhysical memory (RAM) used on the host machine stays above a threshold percentage for longer than a specified duration. 111100Blocked processSQL process is blocked for longer than a specified duration. 121200Long-running queryA SQL query runs for longer than a specified duration. 131400Backup overdueNo full backup exists, or the last full backup is older than a specified time. 141500Log backup overdueNo log backup exists, or the last log backup is older than a specified time. 151600Database unavailableDatabase changes from Online to any other state. 161700Page verificationTorn Page Detection or Page Checksum is not enabled for a database. 171800Integrity check overdueNo entry for an integrity check (DBCC DBINFO returns no date for dbi_dbccLastKnownGood field), or the last check is older than a specified time. 181900Fragmented indexesFragmentation level of one or more indexes is above a threshold percentage. 192400Job duration unusualThe duration of a SQL job duration deviates from its baseline duration by more than a threshold percentage. 202501Clock skewSystem clock time on the Base Monitor computer differs from the system clock time on a monitored SQL Server host machine by a specified number of seconds. 212700SQL Server Agent Service statusThe SQL Server Agent Service status matches the status specified. 222800SQL Server Reporting Service statusThe SQL Server Reporting Service status matches the status specified. 232900SQL Server Full Text Search Service statusThe SQL Server Full Text Search Service status matches the status specified. 243000SQL Server Analysis Service statusThe SQL Server Analysis Service status matches the status specified. 253100SQL Server Integration Service statusThe SQL Server Integration Service status matches the status specified. 263300SQL Server Browser Service statusThe SQL Server Browser Service status matches the status specified. 273400SQL Server VSS Writer Service statusThe SQL Server VSS Writer status matches the status specified. 283501Deadlock trace flag disabledThe monitored SQL Server’s trace flag cannot be enabled. 293600Monitoring stopped (host machine credentials)SQL Monitor cannot contact the host machine because authentication failed. 303700Monitoring stopped (SQL Server credentials)SQL Monitor cannot contact the SQL Server instance because authentication failed. 313800Monitoring error (host machine data collection)SQL Monitor cannot collect data from the host machine. 323900Monitoring error (SQL Server data collection)SQL Monitor cannot collect data from the SQL Server instance. 334000Custom metricThe custom metric value has passed an alert threshold. 344100Custom metric collection errorSQL Monitor cannot collect custom metric data from the target object. Basically, alert.Alert_Type is just a big reference table containing information about the 34 different alert types supported by SQL Monitor (note that the largest id is 41, not 34 – some alert types have been retired since SQL Monitor was first developed). The Name and Description columns are self evident, and I’m going to skip over the Event and Monitoring columns as they’re not very interesting. The AlertId column is the primary key, and is referenced by AlertId in the alert.Alert table. As such, we can rewrite our earlier query to join these two tables, in order to provide a more readable view of the alerts: SELECT TOP 100 AlertId, Name, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType ORDER BY AlertId DESC;  AlertIdNameTargetObjectReadSubType 165550Monitoring error (SQL Server data collection)7:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,9:SqlServer,1,4:Name,s0:,00 265549Monitoring error (host machine data collection)7:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,7:Machine,1,4:Name,s0:,00 365548Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 465547Log backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 565546Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 665545Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 765544Log backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 865543Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 965542Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 1065541Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 Okay, the next column to discuss in the alert.Alert table is TargetObject. Oh boy, this one’s a bit tricky! The TargetObject of an alert is a serialized string representation of the position in the monitored object hierarchy of the object to which the alert pertains. The serialization format is somewhat convenient for parsing in the C# source code of SQL Monitor, and has some helpful characteristics, but it’s probably very awkward to manipulate in T-SQL. I could document the serialization format here, but it would be very dry reading, so perhaps it’s best to consider an example from the table above. Have a look at the alert with an AlertID of 65543. It’s a Backup overdue alert for the SqlMonitorData database running on the default instance of granger, my laptop. Each different alert type is associated with a specific type of monitored object in the object hierarchy (I described the hierarchy in my previous post). The Backup overdue alert is associated with databases, whose position in the object hierarchy is root → Cluster → SqlServer → Database. The TargetObject value identifies the target object by specifying the key properties at each level in the hierarchy, thus: Cluster: Name = "granger" SqlServer: Name = "" (an empty string, denoting the default instance) Database: Name = "SqlMonitorData" Well, look at the actual TargetObject value for this alert: "7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,". It is indeed composed of three parts, one for each level in the hierarchy: Cluster: "7:Cluster,1,4:Name,s7:granger," SqlServer: "9:SqlServer,1,4:Name,s0:," Database: "8:Database,1,4:Name,s14:SqlMonitorData," Each part is handled in exactly the same way, so let’s concentrate on the first part, "7:Cluster,1,4:Name,s7:granger,". It comprises the following: "7:Cluster," – This identifies the level in the hierarchy. "1," – This indicates how many different key properties there are to uniquely identify a cluster (we saw in my last post that each cluster is identified by a single property, its Name). "4:Name,s14:SqlMonitorData," – This represents the Name property, and its corresponding value, SqlMonitorData. It’s split up like this: "4:Name," – Indicates the name of the key property. "s" – Indicates the type of the key property, in this case, it’s a string. "14:SqlMonitorData," – Indicates the value of the property. At this point, you might be wondering about the format of some of these strings. Why is the string "Cluster" stored as "7:Cluster,"? Well an encoding scheme is used, which consists of the following: "7" – This is the length of the string "Cluster" ":" – This is a delimiter between the length of the string and the actual string’s contents. "Cluster" – This is the string itself. 7 characters. "," – This is a final terminating character that indicates the end of the encoded string. You can see that "4:Name,", "8:Database," and "14:SqlMonitorData," also conform to the same encoding scheme. In the example above, the "s" character is used to indicate that the value of the Name property is a string. If you explore the TargetObject property of alerts in your own SQL Monitor data repository, you might find other characters used for other non-string key property values. The different value types you might possibly encounter are as follows: "I" – Denotes a bigint value. For example, "I65432,". "g" – Denotes a GUID value. For example, "g32116732-63ae-4ab5-bd34-7dfdfb084c18,". "d" – Denotes a datetime value. For example, "d634815384796832438,". The value is stored as a bigint, rather than a native SQL datetime value. I’ll describe how datetime values are handled in the SQL Monitor data repostory in a future post. I suggest you have a look at the alerts in your own SQL Monitor data repository for further examples, so you can see how the TargetObject values are composed for each of the different types of alert. Let me give one further example, though, that represents a Custom metric alert, as this will help in describing the final column of interest in the alert.Alert table, SubType. Let me show you the alert I’m interested in: SELECT AlertId, a.AlertType, Name, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType WHERE AlertId = 65769;  AlertIdAlertTypeNameTargetObjectReadSubType 16576940Custom metric7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s6:master,12:CustomMetric,1,8:MetricId,I2,02 An AlertType value of 40 corresponds to the Custom metric alert type. The Name taken from the alert.Alert_Type table is simply Custom metric, but this doesn’t tell us anything about the specific custom metric that this alert pertains to. That’s where the SubType value comes in. For custom metric alerts, this provides us with the Id of the specific custom alert definition that can be found in the settings.CustomAlertDefinitions table. I don’t really want to delve into custom alert definitions yet (maybe in a later post), but an extra join in the previous query shows us that this alert pertains to the CPU pressure (avg runnable task count) custom metric alert. SELECT AlertId, a.AlertType, at.Name, cad.Name AS CustomAlertName, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType JOIN settings.CustomAlertDefinitions cad ON a.SubType = cad.Id WHERE AlertId = 65769;  AlertIdAlertTypeNameCustomAlertNameTargetObjectReadSubType 16576940Custom metricCPU pressure (avg runnable task count)7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s6:master,12:CustomMetric,1,8:MetricId,I2,02 The TargetObject value in this case breaks down like this: "7:Cluster,1,4:Name,s7:granger," – Cluster named "granger". "9:SqlServer,1,4:Name,s0:," – SqlServer named "" (the default instance). "8:Database,1,4:Name,s6:master," – Database named "master". "12:CustomMetric,1,8:MetricId,I2," – Custom metric with an Id of 2. Note that the hierarchy for a custom metric is slightly different compared to the earlier Backup overdue alert. It’s root → Cluster → SqlServer → Database → CustomMetric. Also notice that, unlike Cluster, SqlServer and Database, the key property for CustomMetric is called MetricId (not Name), and the value is a bigint (not a string). Finally, delving into the custom metric tables is beyond the scope of this post, but for the sake of avoiding any future confusion, I’d like to point out that whilst the SubType references a custom alert definition, the MetricID value embedded in the TargetObject value references a custom metric definition. Although in this case both the custom metric definition and custom alert definition share the same Id value of 2, this is not generally the case. Okay, that’s enough for now, not least because as I’m typing this, it’s almost 2am, I have to go to work tomorrow, and my alarm is set for 6am – eek! In my next post, I’ll either cover the remaining three tables in the alert schema, or I’ll delve into the way SQL Monitor stores its monitoring data, as I’d originally planned to cover in this post.

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• When is a SQL function not a function?

  - by Rob Farley

  Should SQL Server even have functions? (Oh yeah – this is a T-SQL Tuesday post, hosted this month by Brad Schulz) Functions serve an important part of programming, in almost any language. A function is a piece of code that is designed to return something, as opposed to a piece of code which isn’t designed to return anything (which is known as a procedure). SQL Server is no different. You can call stored procedures, even from within other stored procedures, and you can call functions and use these in other queries. Stored procedures might query something, and therefore ‘return data’, but a function in SQL is considered to have the type of the thing returned, and can be used accordingly in queries. Consider the internal GETDATE() function. SELECT GETDATE(), SomeDatetimeColumn FROM dbo.SomeTable; There’s no logical difference between the field that is being returned by the function and the field that’s being returned by the table column. Both are the datetime field – if you didn’t have inside knowledge, you wouldn’t necessarily be able to tell which was which. And so as developers, we find ourselves wanting to create functions that return all kinds of things – functions which look up values based on codes, functions which do string manipulation, and so on. But it’s rubbish. Ok, it’s not all rubbish, but it mostly is. And this isn’t even considering the SARGability impact. It’s far more significant than that. (When I say the SARGability aspect, I mean “because you’re unlikely to have an index on the result of some function that’s applied to a column, so try to invert the function and query the column in an unchanged manner”) I’m going to consider the three main types of user-defined functions in SQL Server: Scalar Inline Table-Valued Multi-statement Table-Valued I could also look at user-defined CLR functions, including aggregate functions, but not today. I figure that most people don’t tend to get around to doing CLR functions, and I’m going to focus on the T-SQL-based user-defined functions. Most people split these types of function up into two types. So do I. Except that most people pick them based on ‘scalar or table-valued’. I’d rather go with ‘inline or not’. If it’s not inline, it’s rubbish. It really is. Let’s start by considering the two kinds of table-valued function, and compare them. These functions are going to return the sales for a particular salesperson in a particular year, from the AdventureWorks database. CREATE FUNCTION dbo.FetchSales_inline(@salespersonid int, @orderyear int) RETURNS TABLE AS  RETURN (     SELECT e.LoginID as EmployeeLogin, o.OrderDate, o.SalesOrderID     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101') ) ; GO CREATE FUNCTION dbo.FetchSales_multi(@salespersonid int, @orderyear int) RETURNS @results TABLE (     EmployeeLogin nvarchar(512),     OrderDate datetime,     SalesOrderID int     ) AS BEGIN     INSERT @results (EmployeeLogin, OrderDate, SalesOrderID)     SELECT e.LoginID, o.OrderDate, o.SalesOrderID     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101')     ;     RETURN END ; GO You’ll notice that I’m being nice and responsible with the use of the DATEADD function, so that I have SARGability on the OrderDate filter. Regular readers will be hoping I’ll show what’s going on in the execution plans here. Here I’ve run two SELECT * queries with the “Show Actual Execution Plan” option turned on. Notice that the ‘Query cost’ of the multi-statement version is just 2% of the ‘Batch cost’. But also notice there’s trickery going on. And it’s nothing to do with that extra index that I have on the OrderDate column. Trickery. Look at it – clearly, the first plan is showing us what’s going on inside the function, but the second one isn’t. The second one is blindly running the function, and then scanning the results. There’s a Sequence operator which is calling the TVF operator, and then calling a Table Scan to get the results of that function for the SELECT operator. But surely it still has to do all the work that the first one is doing... To see what’s actually going on, let’s look at the Estimated plan. Now, we see the same plans (almost) that we saw in the Actuals, but we have an extra one – the one that was used for the TVF. Here’s where we see the inner workings of it. You’ll probably recognise the right-hand side of the TVF’s plan as looking very similar to the first plan – but it’s now being called by a stack of other operators, including an INSERT statement to be able to populate the table variable that the multi-statement TVF requires. And the cost of the TVF is 57% of the batch! But it gets worse. Let’s consider what happens if we don’t need all the columns. We’ll leave out the EmployeeLogin column. Here, we see that the inline function call has been simplified down. It doesn’t need the Employee table. The join is redundant and has been eliminated from the plan, making it even cheaper. But the multi-statement plan runs the whole thing as before, only removing the extra column when the Table Scan is performed. A multi-statement function is a lot more powerful than an inline one. An inline function can only be the result of a single sub-query. It’s essentially the same as a parameterised view, because views demonstrate this same behaviour of extracting the definition of the view and using it in the outer query. A multi-statement function is clearly more powerful because it can contain far more complex logic. But a multi-statement function isn’t really a function at all. It’s a stored procedure. It’s wrapped up like a function, but behaves like a stored procedure. It would be completely unreasonable to expect that a stored procedure could be simplified down to recognise that not all the columns might be needed, but yet this is part of the pain associated with this procedural function situation. The biggest clue that a multi-statement function is more like a stored procedure than a function is the “BEGIN” and “END” statements that surround the code. If you try to create a multi-statement function without these statements, you’ll get an error – they are very much required. When I used to present on this kind of thing, I even used to call it “The Dangers of BEGIN and END”, and yes, I’ve written about this type of thing before in a similarly-named post over at my old blog. Now how about scalar functions... Suppose we wanted a scalar function to return the count of these. CREATE FUNCTION dbo.FetchSales_scalar(@salespersonid int, @orderyear int) RETURNS int AS BEGIN     RETURN (         SELECT COUNT(*)         FROM Sales.SalesOrderHeader AS o         LEFT JOIN HumanResources.Employee AS e         ON e.EmployeeID = o.SalesPersonID         WHERE o.SalesPersonID = @salespersonid         AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')         AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101')     ); END ; GO Notice the evil words? They’re required. Try to remove them, you just get an error. That’s right – any scalar function is procedural, despite the fact that you wrap up a sub-query inside that RETURN statement. It’s as ugly as anything. Hopefully this will change in future versions. Let’s have a look at how this is reflected in an execution plan. Here’s a query, its Actual plan, and its Estimated plan: SELECT e.LoginID, y.year, dbo.FetchSales_scalar(p.SalesPersonID, y.year) AS NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID; We see here that the cost of the scalar function is about twice that of the outer query. Nicely, the query optimizer has worked out that it doesn’t need the Employee table, but that’s a bit of a red herring here. There’s actually something way more significant going on. If I look at the properties of that UDF operator, it tells me that the Estimated Subtree Cost is 0.337999. If I just run the query SELECT dbo.FetchSales_scalar(281,2003); we see that the UDF cost is still unchanged. You see, this 0.0337999 is the cost of running the scalar function ONCE. But when we ran that query with the CROSS JOIN in it, we returned quite a few rows. 68 in fact. Could’ve been a lot more, if we’d had more salespeople or more years. And so we come to the biggest problem. This procedure (I don’t want to call it a function) is getting called 68 times – each one between twice as expensive as the outer query. And because it’s calling it in a separate context, there is even more overhead that I haven’t considered here. The cheek of it, to say that the Compute Scalar operator here costs 0%! I know a number of IT projects that could’ve used that kind of costing method, but that’s another story that I’m not going to go into here. Let’s look at a better way. Suppose our scalar function had been implemented as an inline one. Then it could have been expanded out like a sub-query. It could’ve run something like this: SELECT e.LoginID, y.year, (SELECT COUNT(*)     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = p.SalesPersonID     AND o.OrderDate >= DATEADD(year,y.year-2000,'20000101')     AND o.OrderDate < DATEADD(year,y.year-2000+1,'20000101')     ) AS NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID; Don’t worry too much about the Scan of the SalesOrderHeader underneath a Nested Loop. If you remember from plenty of other posts on the matter, execution plans don’t push the data through. That Scan only runs once. The Index Spool sucks the data out of it and populates a structure that is used to feed the Stream Aggregate. The Index Spool operator gets called 68 times, but the Scan only once (the Number of Executions property demonstrates this). Here, the Query Optimizer has a full picture of what’s being asked, and can make the appropriate decision about how it accesses the data. It can simplify it down properly. To get this kind of behaviour from a function, we need it to be inline. But without inline scalar functions, we need to make our function be table-valued. Luckily, that’s ok. CREATE FUNCTION dbo.FetchSales_inline2(@salespersonid int, @orderyear int) RETURNS table AS RETURN (SELECT COUNT(*) as NumSales     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101') ); GO But we can’t use this as a scalar. Instead, we need to use it with the APPLY operator. SELECT e.LoginID, y.year, n.NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID OUTER APPLY dbo.FetchSales_inline2(p.SalesPersonID, y.year) AS n; And now, we get the plan that we want for this query. All we’ve done is tell the function that it’s returning a table instead of a single value, and removed the BEGIN and END statements. We’ve had to name the column being returned, but what we’ve gained is an actual inline simplifiable function. And if we wanted it to return multiple columns, it could do that too. I really consider this function to be superior to the scalar function in every way. It does need to be handled differently in the outer query, but in many ways it’s a more elegant method there too. The function calls can be put amongst the FROM clause, where they can then be used in the WHERE or GROUP BY clauses without fear of calling the function multiple times (another horrible side effect of functions). So please. If you see BEGIN and END in a function, remember it’s not really a function, it’s a procedure. And then fix it. @rob_farley

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