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• Can anyone recommend a payment processing script or service that is as (nearly?) as convenient and c

  - by Jason Livesay

  I have been going through all of the different PayPal integration options and trying to decide which will be the best one for this particular application. I realized that I really want to give users a few options for payment. For example, it might be more convenient to enter their credit card information rather than being sent over to PayPal, or they may have already setup their Google Checkout and so want to use that. So that brings me fairly quickly to the realization that maybe I don't want to program one or two or three API integrations myself and I should look at some shopping cart software. However, we really don't need a whole shopping cart -- we will have a specific form and some other custom coding and the only part of the shopping cart we would really use would be the checkout page to handle accepting payment/integrating with PayPal/Google Checkout/Authorize.net. I like how simple eJunkie makes things and the fact that it accepts PayPal and Google Checkout and Authorize.net. The problem is that the Add To Cart buttons aren't going to cut it. I need to be able to programmatically enter items into the cart. Maybe I can just use an open source PHP shopping cart and skip the store front somehow.

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• an algorhithm for filtering out raw txt files

  - by Roman Luštrik

  Imagine you have a .txt file of the following structure: >>> header >>> header >>> header K L M 200 0.1 1 201 0.8 1 202 0.01 3 ... 800 0.4 2 >>> end of file 50 0.1 1 75 0.78 5 ... I would like to read all the data except lines denoted by >>> and lines below the >>> end of file line. So far I've solved this using read.table(comment.char = ">", skip = x, nrow = y) (x and y are currently fixed). This reads the data between the header and >>> end of file. However, I would like to make my function a bit more plastic regarding the number of rows. Data may have values larger than 800, and consequently more rows. I could scan or readLines the file and see which row corresponds to the >>> end of file and calculate the number of lines to be read. What approach would you use?

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• C++: Simple data type for a variable in IF statement?

  - by Jason

  I am new to C++ and am making a simple text RPG, anyway, The scenario is I have a "welcome" screen with choices 1-3, and have a simple IF statement to check them, here: int choice; std::cout << "--> "; std::cin >> choice; if(choice == 1) { //.. That works fine, but if someone enters a letter as selection (instead of 1, 2 or 3) it'll become "-392493492"or something and crash the program. So I came up with: char choice; std::cout << "--> "; std::cin >> choice; if(choice == 1) { //.. This works kinda fine, but when I enter a number it seems to skip the IF statements completely.. Is the char "1" the same as the number 1? I get a compiler errro with this (ISO-CPP or something): if(choice == "1") So how on earth do I see if they entered 1-3 correctly!?

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• Help me convert .NET 1.1 Xml validation code to .NET 2.0 please.

  - by Hamish Grubijan

  It would be fantastic if you could help me rid of these warnings below. I have not been able to find a good document. Since the warnings are concentrated in just the private void ValidateConfiguration( XmlNode section ) section, hopefully this is not terribly hard to answer, if you have encountered this before. Thanks! 'System.Configuration.ConfigurationException.ConfigurationException(string)' is obsolete: 'This class is obsolete, to create a new exception create a System.Configuration!System.Configuration.ConfigurationErrorsException' 'System.Xml.XmlValidatingReader' is obsolete: 'Use XmlReader created by XmlReader.Create() method using appropriate XmlReaderSettings instead. http://go.microsoft.com/fwlink/?linkid=14202' private void ValidateConfiguration( XmlNode section ) { // throw if there is no configuration node. if( null == section ) { throw new ConfigurationException("The configuration section passed within the ... class was null ... there must be a configuration file defined.", section ); } //Validate the document using a schema XmlValidatingReader vreader = new XmlValidatingReader( new XmlTextReader( new StringReader( section.OuterXml ) ) ); // open stream on Resources; the XSD is set as an "embedded resource" so Resource can open a stream on it using (Stream xsdFile = XYZ.GetStream("ABC.xsd")) using (StreamReader sr = new StreamReader(xsdFile)) { vreader.ValidationEventHandler += new ValidationEventHandler(ValidationCallBack); vreader.Schemas.Add(XmlSchema.Read(new XmlTextReader(sr), null)); vreader.ValidationType = ValidationType.Schema; // Validate the document while (vreader.Read()) { } if (!_isValidDocument) { _schemaErrors = _sb.ToString(); throw new ConfigurationException("XML Document not valid"); } } } // Does not cause warnings. private void ValidationCallBack( object sender, ValidationEventArgs args ) { // check what KIND of problem the schema validation reader has; // on FX 1.0, it gives a warning for "<xs:any...skip" sections. Don't worry about those, only set validation false // for real errors if( args.Severity == XmlSeverityType.Error ) { _isValidDocument = false; _sb.Append( args.Message + Environment.NewLine ); } }

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• Time complexity of a powerset generating function

  - by Lirik

  I'm trying to figure out the time complexity of a function that I wrote (it generates a power set for a given string): public static HashSet<string> GeneratePowerSet(string input) { HashSet<string> powerSet = new HashSet<string>(); if (string.IsNullOrEmpty(input)) return powerSet; int powSetSize = (int)Math.Pow(2.0, (double)input.Length); // Start at 1 to skip the empty string case for (int i = 1; i < powSetSize; i++) { string str = Convert.ToString(i, 2); string pset = str; for (int k = str.Length; k < input.Length; k++) { pset = "0" + pset; } string set = string.Empty; for (int j = 0; j < pset.Length; j++) { if (pset[j] == '1') { set = string.Concat(set, input[j].ToString()); } } powerSet.Add(set); } return powerSet; } So my attempt is this: let the size of the input string be n in the outer for loop, must iterate 2^n times (because the set size is 2^n). in the inner for loop, we must iterate 2*n times (at worst). 1. So Big-O would be O((2^n)*n) (since we drop the constant 2)... is that correct? And n*(2^n) is worse than n^2. if n = 4 then (4*(2^4)) = 64 (4^2) = 16 if n = 100 then (10*(2^10)) = 10240 (10^2) = 100 2. Is there a faster way to generate a power set, or is this about optimal?

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• Navigating the timeline

  - by Dean 'Deacon' Beard

  O.K, being a little new to this, I have hit a brick wall, I'm using AS3 in Flash CS5. All I want to do is have a tweened animation which stops at a frame and which has a clickable button to access another part of the maintime line. Also there will be a button on the animation to skip it. How does one set this up? Obviously you need a stop(); at the stop frame of the time line and an event listener and function for both buttons right? Any more help besides that. I have it set up like this; totalSlides:Number = 60; currentSlideNumber:Number = 1; skipbutton.addEventListener(MouseEvent.CLICK,skipbuttonPress); function skipbuttonPress(evt:MouseEvent):void{ currentframelabel = currentframelabel+1; if(currentSlideNumber>=0){ currentframelabel = introstop; } framelabel.gotoAndStop(introstop); } and the frame it stops on is set up as follows stop(); totalSlides:Number = 60; currentSlideNumber:Number = 5; click01.addEventListener(MouseEvent.CLICK,click01Press); function click01Press( evt : MouseEvent ) : void { currentSlideNumber = currentSlideNumber+1; if (currentSlideNumber >= 0) { currentSlideNumber = 25; } framelabel.gotoAndStop(mainpage); } As I need this for a project, any help would be greatly valued. Many Thanks

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• Datastructure choices for highspeed and memory efficient detection of duplicate of strings

  - by Jonathan Holland

  I have a interesting problem that could be solved in a number of ways: I have a function that takes in a string. If this function has never seen this string before, it needs to perform some processing. If the function has seen the string before, it needs to skip processing. After a specified amount of time, the function should accept duplicate strings. This function may be called thousands of time per second, and the string data may be very large. This is a highly abstracted explanation of the real application, just trying to get down to the core concept for the purpose of the question. The function will need to store state in order to detect duplicates. It also will need to store an associated timestamp in order to expire duplicates. It does NOT need to store the strings, a unique hash of the string would be fine, providing there is no false positives due to collisions (Use a perfect hash?), and the hash function was performant enough. The naive implementation would be simply (in C#): Dictionary<String,DateTime> though in the interest of lowering memory footprint and potentially increasing performance I'm evaluating a custom data structures to handle this instead of a basic hashtable. So, given these constraints, what would you use? EDIT, some additional information that might change proposed implementations: 99% of the strings will not be duplicates. Almost all of the duplicates will arrive back to back, or nearly sequentially. In the real world, the function will be called from multiple worker threads, so state management will need to be synchronized.

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• Asynchronous javascript issue

  - by amit

  I am trying to create a function which takes values from various html elements of the page to create a string and pass on to a variable. now this works great for all browsers except IE 8 and 9. IE tends to skip the part of fetching the values and goes straight to the variable and finds nothing.. is there a way to sync it all so that it works in IE? function seturl() { var qstring = returnQString(); $('span.keyword').text($.trim($('#hdnKeyWord').attr('value'))); $('input.search_box').attr('value', $.trim($('#hdnKeyWord').attr('value'))); $('#hdnSearchKeyword').attr('value', $.trim($('#hdnKeyWord').attr('value'))); $(".search_box").val($.trim($("#hdn_span_hdnKeyWord").text())); $(".header_inner input[type='text']").focus(); $(".search_term input[type='text']").focus(); $('#locationurl').attr('value', qstring); } function returnQString(){ var qstring = $.trim($('#locationurl').attr('init')); //initial value of the url qstring += "?type=" + $('#hdnSTSearch').attr('value'); // type of handler hit qstring += "&keyword=" + encodeURIComponent($('#hdnKeyWord').attr('value')); // keyword addition qstring += "&pagestart=" + $('#current_page').attr('value'); // pagestart(current page) addition qstring += "&pagesize=" + $('#show_per_page').attr('value'); // per page size addition qstring += "&facets=" // facetsearch $.each(selectedFilter.items, function (index, value) { qstring += value.filter + ","; }); qstring += "&selectedSection=" + selectedSection // Section Select return qstring; }

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• Extending jQuery Form Validation Script for new form fields

  - by user982124

  I have a simple HTML form that originally was a series of Questions (A1 to A5 and B1 to B3) with yes/no radio buttons like this: <tr> <td width="88%" valign="top" class="field_name_left">A1</td> <td width="12%" valign="top" class="field_data"> <input type="radio" name="CriteriaA1" value="Yes">Yes<input type="radio" name="CriteriaA1" value="No">No</td> </tr> The user could only answer either the A series of questions OR either the B series of questions, but not both. Also they must complete all questions in either the A or B series. I now have an additional series of questions - C1 to C6 - and need to extend my validation scripts to ensure the user enters either A, B or C and answers all questions within each series. My original script for just the A and B looks like this: $(function() { $("#editRecord").submit(function(){ // is anything checked? if(!checkEmpty()){ $("#error").html("Please check something before submitting"); //alert("nothing Checked"); return false; } // Only A _OR_ B if(isAorB()){ $("#error").html("Please complete A or B, not both"); //alert("please complete A or B, not both"); return false; }; // all A's or all B's if(allAorBChecked()){ $("#error").html("It appears you have not completed all questions"); //alert("missing data"); return false; }; if(haveNo()){ // we're going on, but sending "type = C" } //alert("all OK"); return true; }); }); function checkEmpty(){ var OK = false; $(":radio").each(function(){ if (this.checked){ OK = true; } }); return OK; } function isAorB(){ var OK = false; var Achecked = false; var Bchecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); // if we have an A checked remember it if(theChar == "A" && this.checked && !Achecked){ Achecked = true; } if(Achecked && theChar == "B" && !Bchecked){ if(this.checked){ Bchecked = true; } } if (Achecked && Bchecked){ OK = true; } }); return OK; } function allAorBChecked(){ var notOK = false; var Achecked = false; $(":radio").each(function(){ // skip through to see if we're doing A's or B's var theChar=this.name.charAt(8); // check the A's if(theChar == "A" && this.checked && !Achecked){ Achecked = true; } }); if(Achecked){ // set the input to A $("#type").val("A"); // check _all_ a's are checked var thisName; var thisChecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); var checked = this.checked; if (theChar == "A"){ if (this.name == thisName && !thisChecked){ // Yes wasn't checked - is No? if(!checked){ notOK = true; } } thisChecked = checked; thisName = this.name; } }); }else{ // set the input to B $("#type").val("B"); // check _all_ b's are checked var thisName; var thisChecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); var checked = this.checked; if (theChar == "B"){ if (this.name == thisName && !thisChecked){ // A wasn't checked - is B? if(!checked){ notOK = true; } } thisChecked = checked; thisName = this.name; } }); } return notOK; } function haveNo(){ var thisName; var notOK = false; $(":radio").each(function(){ var checked = this.checked; if (this.name == thisName){ //Is this checked if(checked){ notOK = true; $("#type").val("C"); } } thisName = this.name; }); return notOK; } This worked well but I'm completely stuck at extending it to include the C series. I now have to check that the user hasn't answered any A and B, A and C and B and C questions. Everything I've tried fails to validate. Here's where I'm at right now with my new script: $(function() { $("#editRecord").submit(function(){ // is anything checked? if(!checkEmpty()){ $("#error").html("Please check something before submitting"); //alert("nothing Checked"); return false; } // Only A or B or C if(isAorBorC()){ $("#error").html("Please complete A or B or C, not both"); //alert("please complete A or B, not both"); return false; }; // all A's or all B's or all C's if(allAorBorCChecked()){ $("#error").html("It appears you have not completed all questions"); //alert("missing data"); return false; }; if(haveNo()){ // we're going on, but sending "type = C" } //alert("all OK"); return true; }); }); function checkEmpty(){ var OK = false; $(":radio").each(function(){ if (this.checked){ OK = true; } }); return OK; } function isAorBorC(){ var OK = false; var Achecked = false; var Bchecked = false; var Cchecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); // if we have an A checked remember it if(theChar == "A" && this.checked && !Achecked){ Achecked = true; } if(theChar == "B" && this.checked && !Achecked){ Bchecked = true; } if(theChar == "C" && this.checked && !Achecked){ Cchecked = true; } if(Achecked && theChar == "B" && !Bchecked){ if(this.checked){ Bchecked = true; } } if(Achecked && theChar == "C" && !Cchecked){ if(this.checked){ Cchecked = true; } } if(Bchecked && theChar == "C" && !Cchecked){ if(this.checked){ Cchecked = true; } } if (Achecked && Bchecked){ OK = true; } if (Achecked && CBchecked){ OK = true; } if (Bchecked && Cchecked){ OK = true; } }); return OK; } function allAorBorCChecked(){ var notOK = false; var Achecked = false; $(":radio").each(function(){ // skip through to see if we're doing A's or B's var theChar=this.name.charAt(8); // check the A's if(theChar == "A" && this.checked && !Achecked){ Achecked = true; } }); if(Achecked){ // set the input to A $("#type").val("A"); // check _all_ a's are checked var thisName; var thisChecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); var checked = this.checked; if (theChar == "A"){ if (this.name == thisName && !thisChecked){ // Yes wasn't checked - is No? if(!checked){ notOK = true; } } thisChecked = checked; thisName = this.name; } }); }elseif{ // set the input to B $("#type").val("B"); // check _all_ b's are checked var thisName; var thisChecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); var checked = this.checked; if (theChar == "B"){ if (this.name == thisName && !thisChecked){ // A wasn't checked - is B? if(!checked){ notOK = true; } } thisChecked = checked; thisName = this.name; } }); } return notOK; } }else{ // set the input to C $("#type").val("C"); // check _all_ c's are checked var thisName; var thisChecked = false; $(":radio").each(function(){ var theChar=this.name.charAt(8); var checked = this.checked; if (theChar == "C"){ if (this.name == thisName && !thisChecked){ // A wasn't checked - is B? if(!checked){ notOK = true; } } thisChecked = checked; thisName = this.name; } }); } return notOK; } function haveNo(){ var thisName; var notOK = false; $(":radio").each(function(){ var checked = this.checked; if (this.name == thisName){ //Is this checked if(checked){ notOK = true; $("#type").val("C"); } } thisName = this.name; }); return notOK; } Anyone see what I'm doing wrong?

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• Cannot perform an ORDERBY against my EF4 data

  - by Jaxidian

  I have a query hitting EF4 using STEs and I'm having an issue with user-defined sorting. In debugging this, I have removed the dynamic sorting and am hard-coding it and I still have the issue. If I swap/uncomment the var results = xxx lines in GetMyBusinesses(), my results are not sorted any differently - they are always sorting it ascendingly. FYI, Name is a varchar(200) field in SQL 2008 on my Business table. private IQueryable<Business> GetMyBusinesses(MyDBContext CurrentContext) { var myBusinesses = from a in CurrentContext.A join f in CurrentContext.F on a.FID equals f.id join b in CurrentContext.Businesses on f.BID equals b.id where a.PersonID == 52 select b; var results = from r in myBusinesses orderby "Name" ascending select r; //var results = from r in results // orderby "Name" descending // select r; return results; } private PartialEntitiesList<Business> DoStuff() { var myBusinesses = GetMyBusinesses(); var myBusinessesCount = GetMyBusinesses().Count(); Results = new PartialEntitiesList<Business>(myBusinesses.Skip((PageNumber - 1)*PageSize).Take(PageSize).ToList()) {UnpartialTotalCount = myBusinessesCount}; return Results; } public class PartialEntitiesList<T> : List<T> { public PartialEntitiesList() { } public PartialEntitiesList(int capacity) : base(capacity) { } public PartialEntitiesList(IEnumerable<T> collection) : base(collection) { } public int UnpartialTotalCount { get; set; } }

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• Which options do I have for Java process communication?

  - by Dmitriy Matveev

  We have a place in a code of such form: void processParam(Object param) { wrapperForComplexNativeObject result = jniCallWhichMayCrash(param); processResult(result); } processParam - method which is called with many different arguments. jniCallWhichMayCrash - a native method which is intended to do some complex processing of it's parameter and to create some complex object. It can crash in some cases. wrapperForComplexNativeObject - wrapper type generated by SWIG processResult - a method written in pure Java which processes it's parameter by creation of several kinds (by the kinds I'm not meaning classes, maybe some like hierarchies) of objects: 1 - Some non-unique objects which are referencing each other (from the same hierarchy), these objects can have duplicates created from the invocations of processParam() method with different parameter values. Since it's costly to keep all the duplicates it's necessary to cache them. 2 - Some unique objects which are referencing each other (from the same hierarchy) and some of the objects of 1st kind. After processParam is executed for each of the arguments from some set the data created in processResult will be processed together. The problem is in fact that jniCallWhichMayCrash method may crash the entire JVM and this will be very bad. The reason of crash may be such that it can happen for one argument value and not for the other. We've decided that it's better to ignore crashes inside of JVM and just skip some chunks of data when such crashes occur. In order to do this we should run processParam function inside of separate process and pass the result somehow (HOW? HOW?! This is a question) to the main process and in case of any crashes we will only lose some part of data (It's ok) without lose of everything else. So for now the main problem is implementation of transport between different processes. Which options do I have? I can think about serialization and transmitting of binary data by the streams, but serialization may be not very fast due to object complexity. Maybe I have some other options of implementing this?

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• Can I split a single SQL 2008 DB Table into multiple filegroups, based on a discriminator column?

  - by Pure.Krome

  Hi folks, I've got a SQL Server 2008 R2 database which has a number of tables. Two of these tables contains a lot of large data .. mainly because one of them is VARBINARY(MAX) and the sister table is GEOGRAPHY. (Why two tables? Read Below if you're interested***) The data in these tables are geospatial shapes, such as zipcode boundaries. Now, the first 70K odd rows are for DataType = 1 the rest 5mil rows are for DataType = 2 Now, is it possible to split the table data into two files? so all rows that are for DataType != 2 goes into File_A and DataType = 2 goes into File_B? This way, when I backup the DB, I can skip adding File_B so my download is waaaaay smaller? Is this possible? I guessing you might be thinking - why not keep them as TWO extra tables? Mainly because in the code, the data is conceptually the same .. it's just happens that I want to split the storage of this model data. It really messes up my model if I now how two aggregates in my model, instead of one. ***Entity Framework doesn't like Tables with GEOGRAPHY, so i have to create a new table which transforms the GEOGRAPHY to VARBINARY, and then drop that into EF.

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• Mixing together Connect by, inner join and sum with Oracle

  - by François

  Hey there, I need help with a oracle query. Excuse me in advance for my english. Here is my setup: I have 2 tables called respectively "tasks" and "timesheets". The "tasks" table is a recursive one, that way each task can have multiple subtasks. Each timesheet is associated with a task (not necessarily the "root" task) and contains the number of hours worked on it. Example: Tasks id:1 | name: Task A | parent_id: NULL id:2 | name: Task A1 | parent_id: 1 id:3 | name: Task A1.1 | parent_id: 2 id:4 | name: Task B | parent_id: NULL id:5 | name: Task B1 | parent_id: 4 Timesheets id:1 | task_id: 1 | hours: 1 id:2 | task_id: 2 | hours: 3 id:3 | task_id:3 | hours: 1 id:5 | task_id:5 | hours:1 ... What I want to do: I want a query that will return the sum of all the hours worked on a "task hierarchy". If we take a look at the previous example, It means I would like to have the following results: task A - 5 hour(s) | task B - 1 hour(s) At first I tried this SELECT TaskName, Sum(Hours) "TotalHours" FROM ( SELECT replace(sys_connect_by_path(decode(level, 1, t.name), '~'), '~') As TaskName, ts.hours as hours FROM tasks t INNER JOIN timesheets ts ON t.id=ts.task_id START WITH PARENTOID=-1 CONNECT BY PRIOR t.id = t.parent_id ) GROUP BY TaskName Having Sum(Hours) > 0 ORDER BY TaskName And it almost work. THe only problem is that if there are no timesheet for a root task, it will skip the whole hieararchy... but there might be timesheets for the child rows and it is exactly what happens with Task B1. I know it is the "inner join" part that is causing my problem but I'm not sure how can I get rid of it. Any idea how to solve this problem? Thank you

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• How can one make a 'passthru' function in C++ using macros or metaprogramming?

  - by Ryan

  So I have a series of global functions, say: foo_f1(int a, int b, char *c); foo_f2(int a); foo_f3(char *a); I want to make a C++ wrapper around these, something like: MyFoo::f1(int a, int b, char* c); MyFoo::f2(int a); MyFoo::f3(char* a); There's about 40 functions like this, 35 of them I just want to pass through to the global function, the other 5 I want to do something different with. Ideally the implementation of MyFoo.cpp would be something like: PASSTHRU( f1, (int a, int b, char *c) ); PASSTHRU( f2, (int a) ); MyFoo::f3(char *a) { //do my own thing here } But I'm having trouble figuring out an elegant way to make the above PASSTHRU macro. What I really need is something like the mythical X getArgs() below: MyFoo::f1(int a, int b, char *c) { X args = getArgs(); args++; //skip past implicit this.. ::f1(args); //pass args to global function } But short of dropping into assembly I can't find a good implementation of getArgs().

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• fastest way to check to see if a certain index in a linq statement is null

  - by tehdoommarine

  Basic Details I have a linq statement that grabs some records from a database and puts them in a System.Linq.Enumerable: var someRecords = someRepoAttachedToDatabase.Where(p=>true); Suppose this grabs tons (25k+) of records, and i need to perform operations on all of them. to speed things up, I have to decided to use paging and perform the operations needed in blocks of 100 instead of all of the records at the same time. The Question The line in question is the line where I count the number of records in the subset to see if we are on the last page; if the number of records in subset is less than the size of paging - then that means there are no more records left. What I would like to know is what is the fastest way to do this? Code in Question int pageSize = 100; bool moreData = true; int currentPage = 1; while (moreData) { var subsetOfRecords = someRecords.Skip((currentPage - 1) * pageSize).Take(pageSize); //this is also a System.Linq.Enumerable if (subsetOfRecords.Count() < pageSize){ moreData = false;} //line in question //do stuff to records in subset currentPage++; } Things I Have Considered subsetOfRecords.Count() < pageSize subsetOfRecords.ElementAt(pageSize - 1) == null (causes out of bounds exception - can catch exception and set moreData to false there) Converting subsetOfRecords to an array (converting someRecords to an array will not work due to the way subsetOfRecords is declared - but I am open to changing it) I'm sure there are plenty of other ideas that I have missed.

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• Programming logic best practice - redundant checks

  - by eldblz

  I'm creating a large PHP project and I've a trivial doubt about how to proceed. Assume we got a class books, in this class I've the method ReturnInfo: function ReturnInfo($id) { if( is_numeric($id) ) { $query = "SELECT * FROM books WHERE id='" . $id . "' LIMIT 1;"; if( $row = $this->DBDrive->ExecuteQuery($query, $FetchResults=TRUE) ) { return $row; } else { return FALSE; } } else { throw new Exception('Books - ReturnInfo - id not valid.'); } } Then i have another method PrintInfo function PrintInfo($id) { print_r( $this->ReturnInfo($id) ); } Obviously the code sample are just for example and not actual production code. In the second method should I check (again) if id is numeric ? Or can I skip it because is already taken care in the first method and if it's not an exception will be thrown? Till now I always wrote code with redundant checks (no matter if already checked elsewhere i'll check it also here) Is there a best practice? Is just common sense? Thank you in advance for your kind replies.

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• Paging using Linq-To-Sql based on two parameters in asp.net mvc...

  - by Pandiya Chendur

  As two parameters i say currentPage and pagesize .....I thus far used sql server stored procedures and implemented paging like this, GO ALTER PROCEDURE [dbo].[GetMaterialsInView] -- Add the parameters for the stored procedure here @CurrentPage INT, @PageSize INT AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; SELECT *,ROW_NUMBER() OVER (ORDER BY Id) AS Row FROM ( SELECT *,ROW_NUMBER() OVER (ORDER BY Id) AS Row FROM InTimePagingView ) AS InTimePages WHERE Row >= (@CurrentPage - 1) * @PageSize + 1 AND Row <= @CurrentPage*@PageSize SELECT COUNT(*) as TotalCount FROM InTimePagingView SELECT CEILING(COUNT(*) / CAST(@PageSize AS FLOAT)) NumberOfPages FROM InTimePagingView END Now i am using Linq-to-sql and i use this, public IQueryable<MaterialsObj> FindAllMaterials() { var materials = from m in db.Materials join Mt in db.MeasurementTypes on m.MeasurementTypeId equals Mt.Id where m.Is_Deleted == 0 select new MaterialsObj() { Id = Convert.ToInt64(m.Mat_id), Mat_Name = m.Mat_Name, Mes_Name = Mt.Name, }; return materials; } Now i want to return the records,TotalCount where i use Total count to generate pagenumbers..... Is this possible... Any suggestion... EDIT: Just found this... NorthWindDataContext db = new NorthWindDataContext(); var query = from c in db.Customers select c.CompanyName; //Assuming Page Number = 2, Page Size = 10 int iPageNum = 2; int iPageSize = 10; var PagedData = query.Skip((iPageNum - 1) * iPageSize).Take(iPageSize); ObjectDumper.Write(PagedData);

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• Is there an efficient algorithm to distribute resources in a way that both avoids conflict and allows bias?

  - by Steve V.

  Background (Skip this if you only care about the algorithm) At the university where I work, one of the biggest hassles in our department is classroom scheduling. For illustration purposes and to lay out the scope of the problem, here's how we do scheduling now: Professors give us a list of the classes they're teaching with the time slots they'd prefer to teach, ranked in order of priority (most desired to least desired). Administration gives us a list of the rooms we may assign along with the times those rooms are available for our department's use. We start assigning professors to rooms trying (at first) to take into account the preferences of the various professors. Inevitably, conflicts arise, professors start asking for changes, and the plan falls to pieces somewhere around professor number 30, at which point we start assigning rooms basically wherever we can fit them in, crumpled pieces of paper are everywhere, and nobody's happy. (If you've ever wondered why your class was at 9.30 in the morning on Thursday but 4 pm every other day, now you know) I have been asked to quietly investigate whether software could do this more optimally. The Actual Question Is there an algorithm to efficiently schedule a set of resources such that the following criteria are met: The algorithm must never assign two professors to the same room at the same time. The task is not complete until every professor has been assigned a room / time. The algorithm need not worry about having too many professors for the amount of time slots available. (We're not that well funded.) As much as is possible the algorithm should respect the scheduling preferences of the individual professors. I feel like I can't be the first one to ask this. Is there a efficient algorithm for this, or is this the sort of problem that can only be brute-forced?

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• Issue changing innodb_log_file_size

  - by savageguy

  I haven't done much tweaking in the past so this might be relatively easy however I am running into issues. This is what I do: Stop MySQL Edit my.cnf (changing innodb_log_file_size) Remove ib_logfile0/1 Start MySQL Starts fine however all InnoDB tables have the .frm file is invalid error, the status shows InnoDB engine is disabled so I obviously go back, remove the change and everything works again. I was able to change every other variable I've tried but I can't seem to find out why InnoDB fails to start even after removing the log files. Am I missing something? Thanks. Edit: Pasting of the log below - looks like it still seems to find the log file even though they are not there? Shutdown: 090813 10:00:14 InnoDB: Starting shutdown... 090813 10:00:17 InnoDB: Shutdown completed; log sequence number 0 739268981 090813 10:00:17 [Note] /usr/sbin/mysqld: Shutdown complete Startup after making the changes: InnoDB: Error: log file ./ib_logfile0 is of different size 0 5242880 bytes InnoDB: than specified in the .cnf file 0 268435456 bytes! 090813 11:00:18 [Warning] 'user' entry '[email protected]' ignored in --skip-name-resolve mode. 090813 11:00:18 [Note] /usr/sbin/mysqld: ready for connections. Version: '5.0.81-community-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Edition (GPL) 090813 11:00:19 [ERROR] /usr/sbin/mysqld: Incorrect information in file: './XXXX/User.frm' 090813 11:00:19 [ERROR] /usr/sbin/mysqld: Incorrect information in file: './XXXX/User.frm' 090813 11:00:19 [ERROR] /usr/sbin/mysqld: Incorrect information in file: './XXXX/User.frm' Its just a spam of the same error until I correct it When it did start after it recreated the log files so it must be looking in the same spot I am.

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• Serializing an extended form object

  - by andyperfect

  I've been reading up on this whole subject, but I never came across this specific problem. I already understand that the whole idea of serializing an entire form is a horrible idea and just doesn't work. But, I am encountering a bit of a different problem. I have a class that inherits the "button" form object, that I call DataButton. Now for my problem. I want to be able to serialize this class, but I don't need any of the information from the actual button class. Is there any way to bypass the fact that I can't set the button form object to Serializable() and notify VB that when serialization is to occur, it should simply skip over that information? Theoretically, if such a procedure were possible, I'd be able to do the entire serialization without a hitch. I came up with the idea earlier of removing the "inherits" feature from the class, and having simply a button within the class, but that makes my program really difficult to work with as I am constantly changing the location, size, backgroundImage, text, and whatnot. Thus, immediate updates would be much tougher to work with. Any help would be greatly appreciated.

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• How can I determine the "correct" number of steps in a questionnaire where branching is used?

  - by Mike Kingscott

  I have a potential maths / formula / algorithm question which I would like help on. I've written a questionnaire application in ASP.Net that takes people through a series of pages. I've introduced conditional processing, or branching, so that some pages can be skipped dependent on an answer, e.g. if you're over a certain age, you will skip the page that has Teen Music Choice and go straight to the Golden Oldies page. I wish to display how far along the questionnaire someone is (as a percentage). Let's say I have 10 pages to go through and my first answer takes me straight to page 9. Technically, I'm now 90% of the way through the questionnaire, but the user can think of themselves as being on page 2 of 3: the start page (with the branching question), page 9, then the end page (page 10). How can I show that I'm on 66% and not 90% when I'm on page 9 of 10? For further information, each Page can have a number of questions on that can have one or more conditions on them that will send the user to another page. By default, the next page will be the next one in the collection, but that can be over-ridden (e.g. entire sets of pages can be skipped). Any thoughts? :-s

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• In Xlib, How can I animate until an event occurs?

  - by Animateur

  Hi, I've been trying to animate in a C program using Xlib and I wanna do something when an event occurs, otherwise I wanna keep animating. Here's an example code snippet of what I am doing currently: while( 1 ) { // If an event occurs, stop and do whatever is needed. // If no event occurs, skip this if statement. if ( XEventsQueued( display, QueuedAlready ) > 0 ) { XNextEvent( display, &event ) switch ( event.type ) { // Don't do anything case Expose: while ( event.xexpose.count != 0 ) break; // Do something, when a button is pressed case ButtonPress: ... break; // Do something, when a key is pressed case KeyPress: ... break; } } animate(); // Do animation step i.e. change any drawings... repaint(); // Paint again with the new changes from animation... } So basically, I wanna keep looping if the user hasn't clicked the mouse OR pressed a key in the keyboard yet. When the user presses a key OR clicks the mouse, I wanna stop and do a specific action. The problem in my above code is that, it doesnt stop whenever I do an action. If I remove the if statement, the animation blocks until an event occurs, however I do not want this. It's a simple problem, but I'm kinda new to Xlib/animations so any help would be highly appreciated. Thanks.

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• How to avoid concurrent execution of a time-consuming task without blocking?

  - by Diego V

  I want to efficiently avoid concurrent execution of a time-consuming task in a heavily multi-threaded environment without making threads wait for a lock when another thread is already running the task. Instead, in that scenario, I want them to gracefully fail (i.e. skip its attempt to execute the task) as fast as possible. To illustrate the idea considerer this unsafe (has race condition!) code: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing running = true; try { runExpensiveTask(); } finally { running = false; } } I though about using a variation of Double-Checked Locking (consider that running is a primitive 32-bit field, hence atomic, it could work fine even for Java below 5 without the need of volatile). It could look like this: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing synchronized (ThisClass.class) { if (running) return; running = true; try { runExpensiveTask(); } finally { running = false; } } } Maybe I should also use a local copy of the field as well (not sure now, please tell me). But then I realized that anyway I will end with an inner synchronization block, that still could hold a thread with the right timing at monitor entrance until the original executor leaves the critical section (I know the odds usually are minimal but in this case we are thinking in several threads competing for this long-running resource). So, could you think in a better approach?

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• Object model design choice

  - by spinon

  I am currently working on a ASP.NET MVC reporting application using C#. This is a redesign from a PHP application that was just initially thrown together and is now starting to gain some more traction. SowWe are in the process of reworking the backend to have a more OO approach. One of the descisions I am currently wrestling with is how to structure the domain objects. Since 95% of the site is readonly I am not sure if the typical approaches are practical. Should I create domain objects for the primary pieces of the application (ticket, assignment, assignee) and then create static methods off of these areas to pull the reporting data? Or should I just skip that part and create the chart data classes and have some get method off of these classes? It's not a real big application and currenlty I am the only one developing on it. But I feel torn as to which approach. I feel that the first one is the better choice but maybe overkill given that the majority of uses is for aggregate reporting. Anybody have some good insight on why I should go one way or another?

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• A specific data structure

  - by user550413

  Well, this question is a bit specific but I think there is some general idea in it that I can't get it. Lets say I got K servers (which is a constant that I know its size). I have a program that get requests and every request has an id and server id that will handle it. I have n requests - unknown size and can be any number. I need a data structure to support the next operations within the given complexity: GetServer - the function gets the request ID and returns the server id that is supposed to handle this request at the current situation and not necessarily the original server (see below). Complexity: O(log K) at average. KillServer - the function gets as input a server id that should be removed and another server id that all the requests of the removed server should be passed to. Complexity: O(1) at the worst case. -- Place complexity for all the structure is O(K+n) -- The KillServer function made me think using a Union-Find as I can do the union in O(1) as requested but my problem is the first operation. Why it's LogK? Actually, no matter how I "save" the requests if I want to access to any request (lets say it's an AVL tree) so the complexity will be O(log n) at the worst case and said that I can't assume Kn (and probably K Tried thinking about it a couple of hours but I can't find any solution. Known structures that can be used are: B+ tree, AVL tree, skip list, hash table, Union-Find, rank tree and of course all the basics like arrays and such.

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