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  • How do I cast <T> to varbinary and be still be able to perform a CONVERT on the sql side? Implicatio

    - by Biff MaGriff
    Hello, I'm writing this application that will allow a user to define custom quizzes and then allow another user to respond to the questions. Each question of the quiz has a corresponding datatype. All the responses to all the questions are stored vertically in my [Response] table. I currently use 2 fields to store the response. //Response schema ResponseID int QuizPersonID int QuestionID int ChoiceID int //maps to Choice table, used for drop down lists ChoiceValue varbinary(MAX) //used to store a user entered value I'm using .net 3.5 C# SQL Server 2008. I'm thinking that I would want to store different datatypes in the same field and then in my SQL report proc I would CONVERT to the proper datatype. I'm thinking this is ideal because I only have to check one field. I'm also thinking it might be more trouble than it is worth. I think my other options are to; store the data as strings in the db (yuck), or to have a column for each datatype I might use. So what I would like to know is, how would I format my datatypes in C# so that they can be converted properly in SQL? What is the performance hit for converting in SQL? Should I just make a whole wack of columns for each datatype?

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  • Overlaying 2D paths on UIImage without scaling artifacts

    - by tat0
    I need to draw a path along the shape of an image in a way that it is always matching its position on the image independent of the image scale. Think of this like the hybrid view of Google Maps where streets names and roads are superimposed on top of the aerial pictures. Furthermore, this path will be drawn by the user's finger movements and I need to be able to retrieve the path keypoints on the image pixel coordinates. The user zooms-in in order to more precisely set the paths location. I manage to somehow make it work using this approach: -Create a custom UIView called CanvasView that handles touches interaction and delivers scaling, rotation, translation values to either the UIImageView or PathsView (see bellow) depending on a flag: deliverToImageOrPaths. -Create a UIImageView holding the base image. This is set as a children of CanvasView -Create a custom UIView called PathsView that keeps track of the 2D paths geometry and draws itself with a custom drawRect. This is set as children of the UIImageView. So hierarchy: CanvasView - UIImageView -PathsView In this way when deliverToImageOrPaths is YES, finger gestures transforms both the UIImageView and its child PathsView. When deliverToImageOrPaths is NO the gestures affect only the PathsView altering its geometry. So far so good. QUESTION: The problem I have is that when scaling the base UIImageView (via its .transform property) the PathsView is scaled with aliasing artifacts. drawRect is still being called on the PathsView but I guess it's performing the drawing using the original buffer size and then interpolating. How can I solve this issue? Are there better ways to implement these features? PS: I tried changing the PathsView layer class to CATiledLayer with levelsOfDetailBias 4 and levelsOfDetail 4. It solves the aliasing problem to some extent but it's unacceptable slow to render.

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  • Rot13 for numbers.

    - by dreeves
    EDIT: Now a Major Motion Blog Post at http://messymatters.com/sealedbids The idea of rot13 is to obscure text, for example to prevent spoilers. It's not meant to be cryptographically secure but to simply make sure that only people who are sure they want to read it will read it. I'd like to do something similar for numbers, for an application involving sealed bids. Roughly I want to send someone my number and trust them to pick their own number, uninfluenced by mine, but then they should be able to reveal mine (purely client-side) when they're ready. They should not require further input from me or any third party. (Added: Note the assumption that the recipient is being trusted not to cheat.) It's not as simple as rot13 because certain numbers, like 1 and 2, will recur often enough that you might remember that, say, 34.2 is really 1. Here's what I'm looking for specifically: A function seal() that maps a real number to a real number (or a string). It should not be deterministic -- seal(7) should not map to the same thing every time. But the corresponding function unseal() should be deterministic -- unseal(seal(x)) should equal x for all x. I don't want seal or unseal to call any webservices or even get the system time (because I don't want to assume synchronized clocks). (Added: It's fine to assume that all bids will be less than some maximum, known to everyone, say a million.) Sanity check: > seal(7) 482.2382 # some random-seeming number or string. > seal(7) 71.9217 # a completely different random-seeming number or string. > unseal(seal(7)) 7 # we always recover the original number by unsealing.

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  • Programming test for ASP.NET C# developer job - Opinions please!

    - by Indy
    Hi all, We are hiring a .NET C# developer and I have developed a technical test for the candidates to complete. They have an hour and it has two parts, some knowledge based questions covering asp.net, C# and SQL and a small practical test. I'd appreciate feedback on the test, is it sufficient to test the programmers ability? What would you change if anything? Part One. What the are events fired as part of the ASP.NET Page lifecycle. What interesting things can you do at each? How does ViewState work and why is it either useful or bad? What is a common way to create web services in ASP.NET 2.0? What is the GAC? What is boxing? What is a delegate? The C# keyword .int. maps to which .NET type? Explain the difference between a Stored Procedure and a Trigger? What is an OUTER Join? What is @@IDENTITY? Part Two: You are provided with the Northwind Database and the attached DB relationship diagram. Please create a page which provides users with the following functionality. You don’t need to be too concerned with the presentation detail of the page. Select a customer from a list, and see all the orders placed by that customer. For the same customer, find all their orders which are Beverages and the quantity is more than 5. I was aware of setting the right balance of difficulty on this as there is an hour's test. I was able to complete the practical test in under 30 mins using SQLDatasource and the query designer in visual studio and the test questions, I am looking to see how they approach it logically and whether they use the tools available. Many thanks!

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  • Rails fields_for parameters for a has_many relation don't yield an Array in params

    - by user1289061
    I have a model Sensor with has_many and accepts_nested_attributes_for relationships to another model Watch. In a form to update a Sensor, I have something like the following <%= sensor_form.fields_for :watches do |watches_form| %> <%= watches_form.label :label %><br /> <%= watches_form.text_field :label %> <% end %> This is indended to allow editting of the already-created Watches belonging to a Sensor. This call spits form inputs as so: <input name="sensor[watches_attributes][0][label]" ... /> <input name="sensor[watches_attributes][0][id]" ... /> When this gets submitted, the params object in the Sensor controller gets an assoc like "sensor" => { "id"=>"1", "watches_attributes"=> { "0"=>{"id" => "1", "label" => "foo"}, "1"=>{"id" => "2", "label" => "bar"} } } For a has_many, accepts_nested_attributes_for update to work upon the @sensor.update_attributes call, it seems that that attributes key really must map to an Array. From what I've seen in the examples, the combination of has_many, accepts_nested_attributes_for, and sensor_form.fields_for should allow me to pass the resulting params object directly to @sensor.update_attributes and update each related object as intended. Instead the Sensor takes place, with no errors, but the Watch objects are not updated (since "watches_attributes" maps to a Hash instead of an Array?) Have I missed something?

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  • Flex 3: should I provide prepared data to my component or make it to process data before display?

    - by grapkulec
    I'm starting to learn a little Flex just for fun and maybe to prove that I still can learn something new :) I have some idea for a project and one of its parts is a tree component which could display data in different ways depending on configuration. The idea There is list of objects having properties like id, date, time, name, description. And sometimes list should be displayed like this: first level: date second level: time third level: name and sometimes like this: first level: year second level: month third level: day fourth level: time and name By level I mean level of nesting of course. So, we can have years, that have months, that have days, that have hours and so forth. The problem What could be the best way to do it? I mean, should I prepare data for different ways of nesting outside of component or even outside of flex? I can do it at web service level in C# where I plan to have database access layer and send to flex nice and ready to display XML or array of objects. But I wonder if that won't cause additional and maybe unneccessary network traffic. I tried to hack some code in my component to convert my data objects into XML or ArrayCollection but I don't know enough of Flex and got stuck on elimination of duplicates or getting specific data by some key value. Usually to do such things I have STL with maps, sets and vectors and I find Flex arrays and even Dictionary a little bit confusing (I've read language reference and googled without any significant luck). The question So, to sum things up: should I give my tree component data prepared just for chosen type of display or should I try to do it internally inside component (or some helper class written in ActionScript)?

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  • YUI "Get" utility to parse JSON response?

    - by Sean
    The documentation page for the YUI "Get" utility says: Get Utility is ideal for loading your own scripts or CSS progressively (lazy-loading) or for retrieving cross-domain JSON data from sources in which you have total trust. ...but doesn't have any actual examples for how to do so. Their one example doesn't actually request a JSON document from a remote server, but instead a document containing actual JavaScript along with the JSON data. I'm just interested in the JSON response from the Google Maps API HTTP (REST) interface. Because I can't do cross-site scripting with the "Connect" utility, I am trying the "Get" utility. But merely inserting some JSON data into the page isn't going to do anything, of course. I have to assign it to a variable. But how? Also, just inserting JSON data into the page makes Firefox complain that there's a JavaScript error. And understandably! Plain ol' JSON data isn't going to parse as valid JavaScript. Any ideas?

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  • Best Practice - Removing item from generic collection in C#

    - by Matt Davis
    I'm using C# in Visual Studio 2008 with .NET 3.5. I have a generic dictionary that maps types of events to a generic list of subscribers. A subscriber can be subscribed to more than one event. private static Dictionary<EventType, List<ISubscriber>> _subscriptions; To remove a subscriber from the subscription list, I can use either of these two options. Option 1: ISubscriber subscriber; // defined elsewhere foreach (EventType event in _subscriptions.Keys) { if (_subscriptions[event].Contains(subscriber)) { _subscriptions[event].Remove(subscriber); } } Option 2: ISubscriber subscriber; // defined elsewhere foreach (EventType event in _subscriptions.Keys) { _subscriptions[event].Remove(subscriber); } I have two questions. First, notice that Option 1 checks for existence before removing the item, while Option 2 uses a brute force removal since Remove() does not throw an exception. Of these two, which is the preferred, "best-practice" way to do this? Second, is there another, "cleaner," more elegant way to do this, perhaps with a lambda expression or using a LINQ extension? I'm still getting acclimated to these two features. Thanks. EDIT Just to clarify, I realize that the choice between Options 1 and 2 is a choice of speed (Option 2) versus maintainability (Option 1). In this particular case, I'm not necessarily trying to optimize the code, although that is certainly a worthy consideration. What I'm trying to understand is if there is a generally well-established practice for doing this. If not, which option would you use in your own code?

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  • A map and set which uses contiguous memory and has a reserve function

    - by edA-qa mort-ora-y
    I use several maps and sets. The lack of contiguous memory, and high number of (de)allocations, is a performance bottleneck. I need a mainly STL-compatbile map and set class which can use a contiguous block of memory for internal objects (or multiple blocks). It also needs to have a reserve function so that I can preallocate for expected sizes. Before I write my own I'd like to check what is available first. Is there something in Boost which does this? Does somebody know of an available implementation elsewhere? Intrusive collection types are not usable here as the same objects need to exist in several collections. As far as I know STL memory pools are per-type, not per instance. These global pools are not efficient with respect to memory locality in mutli-cpu/core processing. Object pools don't work as the types will be shared between instance but their pool should not. In many cases a hash map may be an option in some cases.

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  • Examples of monoids/semigroups in programming

    - by jkff
    It is well-known that monoids are stunningly ubiquitous in programing. They are so ubiquitous and so useful that I, as a 'hobby project', am working on a system that is completely based on their properties (distributed data aggregation). To make the system useful I need useful monoids :) I already know of these: Numeric or matrix sum Numeric or matrix product Minimum or maximum under a total order with a top or bottom element (more generally, join or meet in a bounded lattice, or even more generally, product or coproduct in a category) Set union Map union where conflicting values are joined using a monoid Intersection of subsets of a finite set (or just set intersection if we speak about semigroups) Intersection of maps with a bounded key domain (same here) Merge of sorted sequences, perhaps with joining key-equal values in a different monoid/semigroup Bounded merge of sorted lists (same as above, but we take the top N of the result) Cartesian product of two monoids or semigroups List concatenation Endomorphism composition. Now, let us define a quasi-property of an operation as a property that holds up to an equivalence relation. For example, list concatenation is quasi-commutative if we consider lists of equal length or with identical contents up to permutation to be equivalent. Here are some quasi-monoids and quasi-commutative monoids and semigroups: Any (a+b = a or b, if we consider all elements of the carrier set to be equivalent) Any satisfying predicate (a+b = the one of a and b that is non-null and satisfies some predicate P, if none does then null; if we consider all elements satisfying P equivalent) Bounded mixture of random samples (xs+ys = a random sample of size N from the concatenation of xs and ys; if we consider any two samples with the same distribution as the whole dataset to be equivalent) Bounded mixture of weighted random samples Which others do exist?

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  • Quickest algorithm for finding sets with high intersection

    - by conradlee
    I have a large number of user IDs (integers), potentially millions. These users all belong to various groups (sets of integers), such that there are on the order of 10 million groups. To simplify my example and get to the essence of it, let's assume that all groups contain 20 user IDs (i.e., all integer sets have a cardinality of 100). I want to find all pairs of integer sets that have an intersection of 15 or greater. Should I compare every pair of sets? (If I keep a data structure that maps userIDs to set membership, this would not be necessary.) What is the quickest way to do this? That is, what should my underlying data structure be for representing the integer sets? Sorted sets, unsorted---can hashing somehow help? And what algorithm should I use to compute set intersection)? I prefer answers that relate C/C++ (especially STL), but also any more general, algorithmic insights are welcome. Update Also, note that I will be running this in parallel in a shared memory environment, so ideas that cleanly extend to a parallel solution are preferred.

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  • Good mobile oriented GWT widget library alternatives

    - by Michael Donohue
    I've been developing a travel planning site - tripgrep.com - which is built on appengine, GWT and smartgwt, among other technologies. It is still early days, and the site is now working well on my development environment, which is either a windows or mac computer. However, I am frequently talking up the website to my friends when we are at a bar or other venue, so I am standing there while they try to access the site via an iPhone, Android or Blackberry - I've witnessed all three. It has been painfully obvious that the browser based frontend takes a long time to download on a mobile device. I am pretty sure this is because of the javascript download for SmartGWT. So, I would like to look at alternatives to SmartGWT. What I like about SmartGWT is that it has a reasonable look and feel out of the box - I don't need to learn any design or css and it has an office application look. This is considerably better than the GWT built-in widgets, which just get a blue border. The better look-and-feel is why I went with SmartGWT early on. However, the slow load times are killing me on these mobile demos. So now I want a fast loading widget alternative that has good look-and-feel out of the box. The features I care about are: tabs, good form layout, Google maps API integration, grid data viewing. If those are all available in a library that loads quickly on a mobile device, then that's the library I want.

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  • Self-describing file format for gigapixel images?

    - by Adam Goode
    In medical imaging, there appears to be two ways of storing huge gigapixel images: Use lots of JPEG images (either packed into files or individually) and cook up some bizarre index format to describe what goes where. Tack on some metadata in some other format. Use TIFF's tile and multi-image support to cleanly store the images as a single file, and provide downsampled versions for zooming speed. Then abuse various TIFF tags to store metadata in non-standard ways. Also, store tiles with overlapping boundaries that must be individually translated later. In both cases, the reader must understand the format well enough to understand how to draw things and read the metadata. Is there a better way to store these images? Is TIFF (or BigTIFF) still the right format for this? Does XMP solve the problem of metadata? The main issues are: Storing images in a way that allows for rapid random access (tiling) Storing downsampled images for rapid zooming (pyramid) Handling cases where tiles are overlapping or sparse (scanners often work by moving a camera over a slide in 2D and capturing only where there is something to image) Storing important metadata, including associated images like a slide's label and thumbnail Support for lossy storage What kind of (hopefully non-proprietary) formats do people use to store large aerial photographs or maps? These images have similar properties.

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  • Hazelcast Distributed Executor Service KeyOwner

    - by János Veres
    I have problem understanding the concept of Hazelcast Distributed Execution. It is said to be able to perform the execution on the owner instance of a specific key. From Documentation: <T> Future<T> submitToKeyOwner(Callable<T> task, Object key) Submits task to owner of the specified key and returns a Future representing that task. Parameters: task - task key - key Returns: a Future representing pending completion of the task I believe that I'm not alone to have a cluster built with multiple maps which might actually use the same key for different purposes, holding different objects (e.g. something along the following setup): IMap<String, ObjectTypeA> firstMap = HazelcastInstance.getMap("firstMap"); IMap<String, ObjectTypeA_AppendixClass> secondMap = HazelcastInstance.getMap("secondMap"); To me it seems quite confusing what documentation says about the owner of a key. My real frustration is that I don't know WHICH - in which map - key does it refer to? The documentation also gives a "demo" of this approach: import com.hazelcast.core.Member; import com.hazelcast.core.Hazelcast; import com.hazelcast.core.IExecutorService; import java.util.concurrent.Callable; import java.util.concurrent.Future; import java.util.Set; import com.hazelcast.config.Config; public void echoOnTheMemberOwningTheKey(String input, Object key) throws Exception { Callable<String> task = new Echo(input); HazelcastInstance hz = Hazelcast.newHazelcastInstance(); IExecutorService executorService = hz.getExecutorService("default"); Future<String> future = executorService.submitToKeyOwner(task, key); String echoResult = future.get(); } Here's a link to the documentation site: Hazelcast MultiHTML Documentation 3.0 - Distributed Execution Did any of you guys figure out in the past what key does it want?

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  • Delphi: Alternative to using Reset/ReadLn for text file reading

    - by Ian Boyd
    i want to process a text file line by line. In the olden days i loaded the file into a StringList: slFile := TStringList.Create(); slFile.LoadFromFile(filename); for i := 0 to slFile.Count-1 do begin oneLine := slFile.Strings[i]; //process the line end; Problem with that is once the file gets to be a few hundred megabytes, i have to allocate a huge chunk of memory; when really i only need enough memory to hold one line at a time. (Plus, you can't really indicate progress when you the system is locked up loading the file in step 1). The i tried using the native, and recommended, file I/O routines provided by Delphi: var f: TextFile; begin Reset(f, filename); while ReadLn(f, oneLine) do begin //process the line end; Problem withAssign is that there is no option to read the file without locking (i.e. fmShareDenyNone). The former stringlist example doesn't support no-lock either, unless you change it to LoadFromStream: slFile := TStringList.Create; stream := TFileStream.Create(filename, fmOpenRead or fmShareDenyNone); slFile.LoadFromStream(stream); stream.Free; for i := 0 to slFile.Count-1 do begin oneLine := slFile.Strings[i]; //process the line end; So now even though i've gained no locks being held, i'm back to loading the entire file into memory. Is there some alternative to Assign/ReadLn, where i can read a file line-by-line, without taking a sharing lock? i'd rather not get directly into Win32 CreateFile/ReadFile, and having to deal with allocating buffers and detecting CR, LF, CRLF's. i thought about memory mapped files, but there's the difficulty if the entire file doesn't fit (map) into virtual memory, and having to maps views (pieces) of the file at a time. Starts to get ugly. i just want Reset with fmShareDenyNone!

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  • NHibernate Child items query using Parent Id

    - by thorkia
    So I have a set up similar to this questions: Parent Child Setup Everything works great when saving the parent and the children. However, I seem to have a problem when selecting the children. I can't seem to get all the children with a specific parent. This fails with: NHibernate.QueryException: could not resolve property: ParentEntity_id of: Test.Data.ChildEntity Here is my code: public IEnumerable<ChildEntity> GetByParent(ParentEntity parent) { using (ISession session = OrmHelper.OpenSession()) { return session.CreateCriteria<ChildEntity>().Add(Restrictions.Eq("ParentEntity_id ", parent.Id)).List<ChildEntity>(); } } Any help in building a proper function to get all the items would be appreciated. Oh, I am using Fluent NHibernate to construct the mappings - version 1 RTM and NHibernate 2.1.2 GA If you need more information, let me know. As per you request, my fluent mappings: public ParentEntityMap() { Id(x => x.Id); Map(x => x.Name); Map(x => x.Code).UniqueKey("ukCode"); HasMany(x => x.ChildEntity).LazyLoad() .Inverse().Cascade.SaveUpdate(); } public ChildEntityMap() { Id(x => x.Id); Map(x => x.Amount); Map(x => x.LogTime); References(x => x.ParentEntity); } That maps to the following 2 tables: CREATE TABLE "ParentEntity" ( Id integer, Name TEXT, Code TEXT, primary key (Id), unique (Code) ) CREATE TABLE "ChildEntity" ( Id integer, Amount NUMERIC, LogTime DATETIME, ParentEntity_id INTEGER, primary key (Id) ) The data store in SQLite.

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  • Deserialize complex JSON (VB.NET)

    - by Ssstefan
    I'm trying to deserialize json returned by some directions API similar to Google Maps API. My JSON is as follows (I'm using VB.NET 2008): jsontext = { "version":0.3, "status":0, "route_summary": { "total_distance":300, "total_time":14, "start_point":"43", "end_point":"42" }, "route_geometry":[[51.025421,18.647631],[51.026131,18.6471],[51.027802,18.645639]], "route_instructions": [["Head northwest on 43",88,0,4,"88 m","NW",334.8],["Continue on 42",212,1,10,"0.2 km","NW",331.1,"C",356.3]] } So far I came up with the following code: Dim js As New System.Web.Script.Serialization.JavaScriptSerializer Dim lstTextAreas As Output_CloudMade() = js.Deserialize(Of Output_CloudMade())(jsontext) I'm not sure how to define complex class, i.e. Output_CloudMade. I'm trying something like: Public Class RouteSummary Private mTotalDist As Long Private mTotalTime As Long Private mStartPoint As String Private mEndPoint As String Public Property TotalDist() As Long Get Return mTotalDist End Get Set(ByVal value As Long) mTotalDist = value End Set End Property Public Property TotalTime() As Long Get Return mTotalTime End Get Set(ByVal value As Long) mTotalTime = value End Set End Property Public Property StartPoint() As String Get Return mStartPoint End Get Set(ByVal value As String) mStartPoint = value End Set End Property Public Property EndPoint() As String Get Return mEndPoint End Get Set(ByVal value As String) mEndPoint = value End Set End Property End Class Public Class Output_CloudMade Private mVersion As Double Private mStatus As Long Private mRSummary As RouteSummary 'Private mRGeometry As RouteGeometry 'Private mRInstructions As RouteInstructions Public Property Version() As Double Get Return mVersion End Get Set(ByVal value As Double) mVersion = value End Set End Property Public Property Status() As Long Get Return mStatus End Get Set(ByVal value As Long) mStatus = value End Set End Property Public Property Summary() As RouteSummary Get Return mRSummary End Get Set(ByVal value As RouteSummary) mRSummary = value End Set End Property 'Public Property Geometry() As String ' Get ' End Get ' Set(ByVal value As String) ' End Set 'End Property 'Public Property Instructions() As String ' Get ' End Get ' Set(ByVal value As String) ' End Set 'End Property End Class but it does not work. The problem is with complex properties, like route_summary. It is filled with "nothing". Other properties, like "status" or "version" are filled properly. Any ideas, how to define class for the above JSON? Can you share some working code for deserializing JSON in VB.NET? Thanks,

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  • When are SQL views appropriate in ASP.net MVC?

    - by sslepian
    I've got a table called Protocol, a table called Eligibility, and a Protocol_Eligibilty table that maps the two together (a many to many relationship). If I wanted to make a perfect copy of an entry in the Protocol table, and create all the needed mappings in the Protocol_Eligibility table, would using an SQL view be helpful, from a performance standpoint? Protocol will have around 1000 rows, Eligibility will have about 200, and I expect each Protocol to map to about 10 Eligibility rows and each Eligibility to map to over 100 rows in Protocol. Here's how I'm doing this with the view: var pel_original = (from pel in _documentDataModel.Protocol_Eligibility_View where pel.pid == id select pel); Protocol_Eligibility newEligibility; foreach (var pel_item in pel_original) { newEligibility = new Protocol_Eligibility(); newEligibility.Eligibility = (from pel in _documentDataModel.Eligibility where pel.ID == pel_item.eid select pel).First(); newEligibility.Protocol = newProtocol; newEligibility.ordering = pel_item.ordering; _documentDataModel.AddToProtocol_Eligibility(newEligibility); } And this is without the view: var pel_original = (from pel in _documentDataModel.Protocol_Eligibility where pel.Protocol.ID == id select pel); Protocol_Eligibility newEligibility; foreach (var pel_item in pel_original) { pel_item.EligibilityReference.Load(); newEligibility = new Protocol_Eligibility(); newEligibility.Eligibility = pel_item.Eligibility; newEligibility.Protocol = newProtocol; newEligibility.ordering = pel_item.ordering; _documentDataModel.AddToProtocol_Eligibility(newEligibility); }

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  • Thread-safe initialization of function-local static const objects

    - by sbi
    This question made me question a practice I had been following for years. For thread-safe initialization of function-local static const objects I protect the actual construction of the object, but not the initialization of the function-local reference referring to it. Something like this: namspace { const some_type& create_const_thingy() { lock my_lock(some_mutex); static const some_type the_const_thingy; return the_const_thingy; } } void use_const_thingy() { static const some_type& the_const_thingy = create_const_thingy(); // use the_const_thingy } The idea is that locking takes time, and if the reference is overwritten by several threads, it won't matter. I'd be interested if this is safe enough in practice? safe according to The Rules? (I know, the current standard doesn't even know what "concurrency" is, but what about trampling over an already initialized reference? And do other standards, like POSIX, have something to say that's relevant to this?) For the inquiring minds: Many such function-local static const objects I used are maps which are initialized from const arrays upon first use and used for lookup. For example, I have a few XML parsers where tag name strings are mapped to enum values, so I could later switch over the tags enum values.

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  • Error: "Cannot simultaneously fetch multiple bags" when calling Configuration.BuildSessionFactory();

    - by Nick Meldrum
    We are getting this error after upgrading to NHibernate 2.1. [QueryException: Cannot simultaneously fetch multiple bags.] NHibernate.Loader.BasicLoader.PostInstantiate() +418 NHibernate.Loader.Entity.EntityLoader..ctor(IOuterJoinLoadable persister, String[] uniqueKey, IType uniqueKeyType, Int32 batchSize, LockMode lockMode, ISessionFactoryImplementor factory, IDictionary`2 enabledFilters) +123 NHibernate.Loader.Entity.BatchingEntityLoader.CreateBatchingEntityLoader(IOuterJoinLoadable persister, Int32 maxBatchSize, LockMode lockMode, ISessionFactoryImplementor factory, IDictionary`2 enabledFilters) +263 NHibernate.Persister.Entity.AbstractEntityPersister.CreateEntityLoader(LockMode lockMode, IDictionary`2 enabledFilters) +26 NHibernate.Persister.Entity.AbstractEntityPersister.CreateLoaders() +57 NHibernate.Persister.Entity.AbstractEntityPersister.PostInstantiate() +1244 NHibernate.Persister.Entity.SingleTableEntityPersister.PostInstantiate() +18 NHibernate.Impl.SessionFactoryImpl..ctor(Configuration cfg, IMapping mapping, Settings settings, EventListeners listeners) +3261 NHibernate.Cfg.Configuration.BuildSessionFactory() +87 Without stepping into the NHibernate source, it doesn't look like I can see which mapping is creating the issue. It's a very old application with a load of mappings files, lots of mappings have one-to-many bags in them, all lazy instantiated. For example: <bag name="Ownership" lazy="true" cascade="all" inverse="true" outer-join="auto" where="fkOwnershipStatusID!=6"> <key column="fkStakeHolderID"/> <one-to-many class="StakeholderLib.Ownership,StakeholderLib" /> </bag> maps to: public virtual IList Ownership { get { if (ownership == null) ownership = new ArrayList(); return ownership; } set { ownership = value; } } Has anyone seen this error before when upgrading to NHibernate 2.1?

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  • Traceroute comparison and statistics

    - by ben-casey
    I have a number of traceroutes that i need to compare against each other but i dont know the best way to do it, ive been told that hash maps are a good technique but i dont know how to implement them on my code. so far i have: FileInputStream fstream = new FileInputStream("traceroute.log"); // Get the object of DataInputStream DataInputStream in = new DataInputStream(fstream); BufferedReader br = new BufferedReader(new InputStreamReader(in)); String strLine; // reads lines in while ((strLine = br.readLine()) != null) { System.out.println(strLine); } and the output looks like this: Wed Mar 31 01:00:03 BST 2010 traceroute to www.bbc.co.uk (212.58.251.195), 30 hops max, 40 byte packets 1 139.222.0.1 (139.222.0.1) 0.873 ms 1.074 ms 1.162 ms 2 core-from-cmp.uea.ac.uk (10.0.0.1) 0.312 ms 0.350 ms 0.463 ms 3 ueaha1btm-from-uea1 (172.16.0.34) 0.791 ms 0.772 ms 1.238 ms 4 bound-from-ueahatop.uea.ac.uk (193.62.92.71) 5.094 ms 4.451 ms 4.441 ms 5 gi0-3.norw-rbr1.eastnet.ja.net (193.60.0.21) 4.426 ms 5.014 ms 4.389 ms 6 gi3-0-2.chel-rbr1.eastnet.ja.net (193.63.107.114) 6.055 ms 6.039 ms * 7 lond-sbr1.ja.net (146.97.40.45) 6.994 ms 7.493 ms 7.457 ms 8 so-6-0-0.lond-sbr4.ja.net (146.97.33.154) 8.206 ms 8.187 ms 8.234 ms 9 po1.lond-ban4.ja.net (146.97.35.110) 8.673 ms 6.294 ms 7.668 ms 10 bbc.lond-sbr4.ja.net (193.62.157.178) 6.303 ms 8.118 ms 8.107 ms 11 212.58.238.153 (212.58.238.153) 6.245 ms 8.066 ms 6.541 ms 12 212.58.239.62 (212.58.239.62) 7.023 ms 8.419 ms 7.068 ms what i need to do is compare this trace against another one just like it and look for the changes and time differences etc, then print a stats page.

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  • What are the best workarounds for known problems with Hibernate's schema validation of floating poin

    - by Jason Novak
    I have several Java classes with double fields that I am persisting via Hibernate. For example, I have @Entity public class Node ... private double value; When Hibernate's org.hibernate.dialect.Oracle10gDialect creates the DDL for the Node table, it maps the value field to a "double precision" type. create table MDB.Node (... value double precision not null, ... It would appear that in Oracle, "double precision" is an alias for "float". So, when I try to verify the database schema using the org.hibernate.cfg.AnnotationConfiguration.validateSchema() method, Oracle appears to describe the value column as a "float". This causes Hibernate to throw the following Exception org.hibernate.HibernateException: Wrong column type in DBO.ACL_RULE for column value. Found: float, expected: double precision A very similar problem is listed in Hibernate's JIRA database as HHH-1961 (http://opensource.atlassian.com/projects/hibernate/browse/HHH-1961). I'd like to avoid doing anything that will break MySql, Postgres, and Sql Server support so extending the Oracle10gDialect appears to be the most promising of the workarounds mentioned in HHH-1961. But extending a Dialect is something I've never done before and I'm afraid there may be some nasty gotchas. What is the best workaround for this problem that won't break our compatibility with MySql, Postgres, and Sql Server? Thanks for taking the time to look at this!

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  • Making Javascript and HTML5 games

    - by Jeff Meatball Yang
    A long time ago (Netscape 4-era), I wrote Javascript-based games: Pong, Minesweeper, and John Conway's Life among them. I'm getting back into it, and want to get my hands even dirtier. I have a few games in mind: Axis & Allies clone, with rugged maps and complex rules. Tetris clone, possibly with real-time player-vs-player or player-vs-computer mode Breakout clone, with a couple weapons and particle velocities In all of these, I have only a few objectives: Use JavaScript and HTML 5 - it should run on Chrome, Safari, or maybe an iPad. Start small and simple, then build-up features. Learn something new about game design and implementation. So my questions are: How would you implement these games? Do you have any technology recommendations? If you've written these games, what was the hardest part? N.B. I also want to start from first-principles - if you recommend a framework/library, I would appreciate some theory or implementation details behind it. These games are different enough that I should learn something new from each one.

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  • ASP.Net MVC ActionLink's and Shared Hosting Aliased Domains

    - by Peter Meyer
    So, I've read this and I've got a similar issue: I have a shared hosting account (with GoDaddy, though that's not exactly relevant, I believe) and I've got an MVC (RC1) site deployed to a sub-folder which where I have another domain name mapped (or aliased). The sub-folder is also setup as an application root as well. The site works without issue, the problem is that I don't like the links that are being generated using Html.ActionLink and Ajax.ActionLink. It's inserting the sub folder name as part of the URL as described in this other question. Thing is, the site works fine, but I'd like to make the links generated relative to the domain name. To use an example: http://my.abc.com "primary" domain; maps to \ on file system http://my.xyz.com setup to map to \_xyz.com folder on file system My generated links on xyz.com look like this: Intended Generated -------- --------- http://my.xyz.com/Ctrller/Action/52 http://my.xyz.com/_xyz.com/Ctrller/Action/52 and, FWIW, the site works. So, the question: Is there something I can do to get rid of that folder name in the links being generated? I have a couple of brute force ideas, but they aren't too elegant.

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  • Using jQuery tools from within GWT -- is there a way to allow exchanges?

    - by culov
    I have a GWT web-app with a nearly full page Google map window. Inside the the map, I have infowindows which include links. What I want to do is use jquery tools overlays (http://flowplayer.org/tools/overlay/apple.html) to open the overlay and display it on top of the map once the link inside the info window is clicked. Now, the link source is generated dynamically, and it is hosted on a different server, so i have to open it in an iframe and set the source of the iframe before it opens. this seems simple enough since i only have 1 iframe on the page: function changeSource(url){ $("#menuIFrame").attr("src",url); } To call this before opening the overlay (which is done on mouse release), i create the following element in the google maps infowindow via GWT: <a href="http://whatever.com/menu/" onClick="changeSource('http://whatever.com/menu/');" rel=#menu"> View menu </a> Jquery tools works by opening whatever div has the id assigned to the value of 'rel', but because i have my javascript/jquery on my LandingPage.html in GWT, there appears to be some sort of disconnect between the two because the changeSource function is never called AND the overlay is never added to the window. Here's my app: http://truxmapper.appspot.com/ As you can see, the other overlays will work fine, but once you click an infowindow and try to view the menu, it will simply use the href to open the url in that window. Does anyone know of a solution that will allow me to accomplish my goal? Thanks!

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