Search Results

Search found 1848 results on 74 pages for 'significant'.

Page 54/74 | < Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >

  • Smoothing touch-based animation in iPhone OpenGL?

    - by quixoto
    I know this is vague, but looking for general tips/help on this, as it's not an area of significant expertise for me. I have some iPhone code that's basically an EAGL view handling a single touch. The app draws (using GL) a circle via triangle fan at the touch point, and moves it when the user moves the touch point, and re-renders the view then. When dragging a finger slowly, the circle keeps up and consistent with the finger as it moves. If I scribble my finger quickly back and forth across the screen, the rendering doesn't keep up with the touch motion, so you see an optical illusion of "multiple" discrete circles on the screen "at once". (Normal persistence of vision illusion). This optical illusion is jarring. How can I make this look more natural? Can I blur the motion of the circle somehow? Is this result the evidence of some bad frame rate issue? I see this artifact even when nothing else is being rendered, so I think this might just be as fast as we can go. Any hints or suggestions? Much appreciated. Thanks.

    Read the article

  • Resources related to data-mining and gaming on social networks

    - by darren
    Hi all I'm interested in the problem of patterning mining among players of social networking games. For example detecting cheaters of a game, given a company's user database. So far I have been following the usual recipe for a data mining project: construct a data warehouse that aggregates significant information select a classifier, and train it with a subsectio of records from the warehouse validate classifier with another test set lather, rinse, repeat Surprisingly, I've found very little in this area regarding literature, best practices, etc. I am hoping to crowdsource the information gathering problem here. Specifically what I'm looking for: What classifiers have worked will for this type of pattern mining (it seems highly temporal, users playing games, users receiving rewards, users transferring prizes etc). Are there any highly agreed upon attributes specific to social networking / gaming data? What is a practical amount of information that should be considered? One problem I've run into is data overload, where queries and data cleansing may take days to complete. Related to point above, what hardware resources are required to produce results? I've found it difficult to estimate the amount of computing power I will require for production use. It has become apparent that a white box in the corner does not have enough horse-power for such a project. Are companies generally resorting to cloud solutions? Are they buying clusters? Basically, any resources (theoretical, academic, or practical) about implementing a social networking / gaming pattern-mining program would be very much appreciated. Thanks.

    Read the article

  • PDFView printWithInfo:autoRotate: fails

    - by Brian Postow
    I'm trying to print a PDFDocument that I am constructing from a series of images. In case it matters, I'm doing all of this from within a Mozilla plugin. I create the PDFDocument, and put it into a PDFView, then I call [printView printWithInfo: [NSPrintInfo sharedPrintInfo] autoRotate: YES]; The print dialog comes up (as a separate window, instead of panel. I assume that that comes from being inside a mozilla window, so I wasn't too worried about it. The dialog shows my document, and I can page through it correctly, and everything looks good. However, when I hit "Print" the dropdown with "Layout" etc becomes empty, and the view under that becomes empty. The window doesn't disappear, and the document doesn't print. Hitting Cancel does exactly the same thing. The only thing I can do then is force-quit Mozillla. I based the program off of PDFKitLinker2 from the apple dev site, and that program works. But I can't see any significant differences between it and my version. Any suggestions on where to look? thanks. EDIT: Yes, I know that this is pretty much an exact duplicate of http://stackoverflow.com/questions/2058501/printing-off-screen-pdfviews but that never got a sufficient answer... (And I didn't notice it until just now...)

    Read the article

  • How to explain to users the advantages of dumb primary key?

    - by Hao
    Primary key attractiveness I have a boss(and also users) that wants primary key to be sophisticated/smart/attractive control number(sort of like Social Security number, or credit card number format) I just padded the primary key(in Views) with zeroes to appease their desire to make the control number sophisticated,smart and attractive. But they wanted it as: first 2 digits as client code, then 4 digits as year year, then last 4 digits as transaction number on that client on a given year, then reset the transaction number of client to 1 when next year flows. Each client's transaction starts with 1. e.g. WM20090001, WM20090002, BB2009001, WM20100001, BB20100001 But as I wanted to make things as simple as possible, I forgo embedding their suggested smartness in primary key, I just keep the primary key auto increments regardless of client and year. But to make it not dull-looking(they really are adamant to make the primary key as smart control number), I made the primary key appears to them smart, on view query, I put the client code and four digit year code on front of the eight-zero padded autoincrement key, i.e. WM200900000001. Sort of slug-like information on autoincremented primary key. Keeping primary key autoincrement regardless of any other information, we are able keep other potential side effects problem when they edit a record, for example, if they made a mistake of entering the transaction on WM, then they edit the client code to BB, if we use smart primary key, the primary keys of WM customer will have gaps in their control number. Or worse yet, instead of letting the control numbers have gaps/holes, the user will request that subsequent records of that gap should shift up to that gap and have their subsequent primary keys re-adjust(decremented). How do you deal with these user requests(reasonable or otherwise)? Do you yield to their request? Or just continue using dumb primary key and explain them the repercussions of having a very smart/sophisticated primary key and educate them the significant advantages of having a dumb primary key? P.S. quotable quote(http://articles.techrepublic.com.com/5100-10878_11-1044961.html): "If you hold your tongue the first time users ask what is for them a reasonable request, things will work a lot better in the end."

    Read the article

  • Silverlight DataForm Memory Leak

    - by Andrew Garrison
    Some Background I have noticed that setting the EditTemplate of a DataForm (from the Silverlight Toolkit) can cause the DataForm to not be garbage collected. Consequently, the parent control of the DataForm cannot be garbage collected either, causing a very significant memory leak. Here's some XAML which demonstrates the case. <toolkit:DataForm HorizontalAlignment="Stretch" Margin="10" VerticalAlignment="Stretch"> <toolkit:DataForm.EditTemplate> <DataTemplate> <toolkit:DataField Label="Dummy Binding:"> <TextBox Text="{Binding DummyBinding, Mode=TwoWay}" /> </toolkit:DataField> </DataTemplate> </toolkit:DataForm.EditTemplate> </toolkit:DataForm> I have opened an issue on CodePlex. The isssue has an attachment which has a project which desmonstrates the case. So, My Question Is Has anyone else encountered this issue? More importantly, does anyone know of any workarounds? How can I force this DataForm to be garbage collected?

    Read the article

  • Manditory read-only fields in django

    - by jamida
    I'm writing a test "grade book" application. The models.py file is shown below. class Student(models.Model): name = models.CharField(max_length=50) parent = models.CharField(max_length=50) def __unicode__(self): return self.name class Grade(models.Model): studentId = models.ForeignKey(Student) finalGrade = models.CharField(max_length=3) I'd like to be able to change the final grade for several students in a modelformset but for now I'm just trying one student at a time. I'm also trying to create a form for it that shows the student name as a field that can not be changed, the only thing that can be changed here is the finalGrade. So I used this trick to make the studentId read-only. class GradeROForm(ModelForm): studentId = forms.ModelChoiceField(queryset=Student.objects.all()) def __init__(self, *args, **kwargs): super(GradeROForm,self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) if instance and instance.id: self.fields['studentId'].widget.attrs['disabled']='disabled' def clean_studentId(self): instance = getattr(self,'instance',None) if instance: return instance.studentId else: return self.cleaned_data.get('studentId',None) class Meta: model=Grade And here is my view: def modifyGrade(request,student): student = Student.objects.get(name=student) mygrade = Grade.objects.get(studentId=student) if request.method == "POST": myform = GradeROForm(data=request.POST, instance=mygrade) if myform.is_valid(): grade = myform.save() info = "successfully updated %s" % grade.studentId else: myform=GradeROForm(instance=mygrade) return render_to_response('grades/modifyGrade.html',locals()) This displays the form like I expect, but when I hit "submit" I get a form validation error for the student field telling me this field is required. I'm guessing that, since the field is "disabled", the value is not being reported in the POST and for reasons unknown to me the instance isn't being used in its place. I'm a new Django/Python programmer, but quite experienced in other languages. I can't believe I've stumbled upon such a difficult to solve problem in my first significant django app. I figure I must be missing something. Any ideas?

    Read the article

  • Practical value for concurrent-request-timeout parameter

    - by Andrei
    In the Seam Reference Guide, one can find this paragraph: We can set a sensible default for the concurrent request timeout (in ms) in components.xml: <core:manager concurrent-request-timeout="500" /> However, we found that 500 ms is not nearly enough time for most of the cases we had to deal with, especially with the severe restriction seam places on conversation access. In our application we have a combination of page scoped ajax requests (triggered by various use actions), some global scoped polling notification logic (part of the header, so included in every page) and regular links that invoke actions and/or navigate to other pages. Therefore, we get the dreaded concurrent access to conversation exception way too often, even without any significant load on the site. After researching the options for quite a bit, we ended up bumping this value to several seconds (we're debating whether to bump it up to 10s), as none of the recommended solutions seemed able to solve our issue completely (even forcing a global queue for all the ajax requests would still leave us exposed to a user deciding to click a link right when one of our polling calls was in progress). And we'd much rather have the users wait for a second or two instead of getting an error page just because they clicked a link at the wrong moment. And now to the question: is there something obvious we're missing (like a way to allow concurrent access to conversations and taking care of the needed locking ourselves, for instance :)? How do people solve this problem (ajax requests mixed with user driven interaction) in seam? Disabling all the links on the page while ajax requests are in progress (as suggested by one blog page) is really not a viable option. Any other suggestions? TIA, Andrei

    Read the article

  • Compression algorithm for IEEE-754 data

    - by David Taylor
    Anyone have a recommendation on a good compression algorithm that works well with double precision floating point values? We have found that the binary representation of floating point values results in very poor compression rates with common compression programs (e.g. Zip, RAR, 7-Zip etc). The data we need to compress is a one dimensional array of 8-byte values sorted in monotonically increasing order. The values represent temperatures in Kelvin with a span typically under of 100 degrees. The number of values ranges from a few hundred to at most 64K. Clarifications All values in the array are distinct, though repetition does exist at the byte level due to the way floating point values are represented. A lossless algorithm is desired since this is scientific data. Conversion to a fixed point representation with sufficient precision (~5 decimals) might be acceptable provided there is a significant improvement in storage efficiency. Update Found an interesting article on this subject. Not sure how applicable the approach is to my requirements. http://users.ices.utexas.edu/~burtscher/papers/dcc06.pdf

    Read the article

  • E-commerce platform for custom application integration

    - by Zach Smith
    We are building an online subscription-based website and I'm looking for recommendations on which e-commerce platform to use for the checkout process. Requirements include: Only four products. The sign-up process of the site is heavily customized, and after checkout the user should automatically get logged into the subscriber area. Subscriptions will last one year and can be renewed manually. Support for coupons/discount codes at a later point. Since the entire application is custom, we've weighed building a custom checkout but are strongly leaning towards using existing software to avoid having to build lots of admin reporting as well as a coupon engine down the road. The two questions we're pondering are: Is it better to a) build our application custom and use whatever e-commerce software we select just for the payment piece, or b) use the e-commerce software as the basis and build our application around it/as a module/etc? Which e-commerce platform should we use? I've looked into a variety of off the shelf e-commerce software, but it's not clear to me which would be easiest to integrate with. I've researched on the Web and looked at many of the threads on SO to compiled a list of potential candidates: www.magentocommerce.com/ (seems difficult to integrate with) www.prestashop.com/ www.nopcommerce.com/ www.opencart.com/ www.cubecart.com/ www.spreecommerce.com/ www.interspire.com/ www.tradingeye.com/ We're most concerned with the level of effort required with ramping up on the software and then doing the integration with our custom functionality. We're most proficient with PHP, ASP.NET and some ROR and are only considering those technologies. We prefer open source, but would be open to commercial if there's a significant upside. Any experiences with similar projects and advice is greatly appreciated.

    Read the article

  • Java equivalent to VS solution file

    - by Chris
    I'm a C# guy trying to learn Java. I understand the syntax and the basic architecture of the Java platform, and have no problem doing smaller projects myself, but I'd really like to be able to download some open source projects to learn from the work of others. However, I'm running into a stumbling block that I can't seem to find any information on. When I download an open source .NET project, I can open the .sln file with visual studio and everything just loads. Sure, there's occasionally a missing reference or something, but there's really very little configuration required to get things going. I'm not sensing the same ease of use with Java. I'm using eclipse at the moment, and it feels like for every project I have to create a brand new Eclipse project using "create from existing source", and almost nothing compiles properly without significant reconfiguration. In the case of web projects, it's even worse, because Eclipse doesn't appear to support creating a web project from existing source. I have to create a standard Java project from source, then then apparently modify the project file to include the bindings for the web toolkit stuff to work properly. Assuming I want to be able to contribute to a project later on, I shouldn't have to be making such drastic changes to the file structure to get my IDE to a workable state. What am I missing?

    Read the article

  • MKAnnotationView is not added for some annotations

    - by Dave
    I find that MKMapView has to be re-centered to a significant distance away from an existing map center to be able to add more annotations to the map and DISPLAY them. Is this a bug in SDK 3.2? I have looked literally EVERYWHERE and can't find a way to refresh the map view without having to zoom in or zoom out or move the map view. Why?? I don't mind if the solution involves doing a bunch of custom delegates and notifications. I just NEED this so bad. Basically, I am adding pins (annotations) to a map view when performing a search for businesses. I remove existing annotations on every search. So the annotations are added to the map on every search. If I search twice with the same map view, I see the results loading but the map view is empty. The pins will appear if i move/resize/zoom in. Anybody seen this? any help is appreciated.

    Read the article

  • Problems with Merb on Snow Leopard

    - by hamhoagie
    I've recently started looking at Merb, for use with some small projects around the office. I'm trying to set up my first project following the docs, and am encountering an exception such as: foo:beta user$ merb Merb root at: /Users/user/code/merb/beta Loading init file from ./config/init.rb Loading ./config/environments/development.rb ~ Connecting to database... ~ Loaded slice 'MerbAuthSlicePassword' ... ~ Parent pid: 39794 ~ Compiling routes... ~ Activating slice 'MerbAuthSlicePassword' ... ~ ~ FATAL: Mongrel is not installed, but you are trying to use it. You need to either install mongrel or a different Ruby web server, like thin. I have installed Mongrel from gem as well as from MacPorts, and am confused by this exception. Significant stats: ruby 1.8.7 (2010-01-10 patchlevel 249) [i686-darwin10] From my installed gems: merb (1.1.0) merb-action-args (1.1.0) merb-assets (1.1.0) merb-auth (1.1.0) merb-auth-core (1.1.0) merb-auth-more (1.1.0) merb-auth-slice-password (1.1.0) merb-cache (1.1.0) merb-core (1.1.0) merb-exceptions (1.1.0) merb-gen (1.1.0) merb-haml (1.1.0) merb-helpers (1.1.0) merb-mailer (1.1.0) merb-param-protection (1.1.0) merb-slices (1.1.0) merb_datamapper (1.1.0) mongrel (1.1.5) Merb documentation is non-existent, so I find myself stuck. Thanks in advance.

    Read the article

  • Scalable / Parallel Large Graph Analysis Library?

    - by Joel Hoff
    I am looking for good recommendations for scalable and/or parallel large graph analysis libraries in various languages. The problems I am working on involve significant computational analysis of graphs/networks with 1-100 million nodes and 10 million to 1+ billion edges. The largest SMP computer I am using has 256 GB memory, but I also have access to an HPC cluster with 1000 cores, 2 TB aggregate memory, and MPI for communication. I am primarily looking for scalable, high-performance graph libraries that could be used in either single or multi-threaded scenarios, but parallel analysis libraries based on MPI or a similar protocol for communication and/or distributed memory are also of interest for high-end problems. Target programming languages include C++, C, Java, and Python. My research to-date has come up with the following possible solutions for these languages: C++ -- The most viable solutions appear to be the Boost Graph Library and Parallel Boost Graph Library. I have looked briefly at MTGL, but it is currently slanted more toward massively multithreaded hardware architectures like the Cray XMT. C - igraph and SNAP (Small-world Network Analysis and Partitioning); latter uses OpenMP for parallelism on SMP systems. Java - I have found no parallel libraries here yet, but JGraphT and perhaps JUNG are leading contenders in the non-parallel space. Python - igraph and NetworkX look like the most solid options, though neither is parallel. There used to be Python bindings for BGL, but these are now unsupported; last release in 2005 looks stale now. Other topics here on SO that I've looked at have discussed graph libraries in C++, Java, Python, and other languages. However, none of these topics focused significantly on scalability. Does anyone have recommendations they can offer based on experience with any of the above or other library packages when applied to large graph analysis problems? Performance, scalability, and code stability/maturity are my primary concerns. Most of the specialized algorithms will be developed by my team with the exception of any graph-oriented parallel communication or distributed memory frameworks (where the graph state is distributed across a cluster).

    Read the article

  • SQL Server 2008 Running trigger after Insert, Update locks original table

    - by Polity
    Hi Folks, I have a serious performance problem. I have a database with (related to this problem), 2 tables. 1 Table contains strings with some global information. The second table contains the string stripped down to each individual word. So the string is like indexed in the second table, word by word. The validity of the data in the second table is of less important then the validity of the data in the first table. Since the first table can grow like towards 1*10^6 records and the second table having an average of like 10 words for 1 string can grow like 1*10^7 records, i use a nolock in order to read the second this leaves me free for inserting new records without locking it (Expect many reads on both tables). I have a script which keeps on adding and updating rows to the first table in a MERGE statement. On average, the data beeing merged are like 20 strings a time and the scripts runs like ones every 5 seconds. On the first table, i have a trigger which is beeing invoked on a Insert or Update, which takes the newly inserted or updated data and calls a stored procedure on it which makes sure the data is indexed in the second table. (This takes some significant time). The problem is that when having the trigger disbaled, Reading the first table happens in a few ms. However, when enabling the trigger and your in bad luck of trying to read the first table while this is beeing updated, Our webserver gives you a timeout after 10 seconds (which is way to long anyways). I can quess from this part that when running the trigger, the first table is kept (partially) in a lock untill the trigger is completed. What do you think, if i'm right, is there a easy way around this? Thanks in advance! Cheers, Koen

    Read the article

  • .NET WF4: Should it be in the middle of everything?

    - by stimpy77
    I am aware that WF4 (Windows Workflow 4.0, part of .NET 4.0) is a significant rework and redesign of WF3, where much of what made WF3 a poor technology choice has been cleaned up in WF4. For example, as far as I can tell, WF4 (Windows Workflow 4.0) activities are more or less testable with [TestMethod] and mocking. This among other things, like improved performance, has grabbed my attention about the technology again, whereas I had previously pooh-poohed WF3. I'm working on a new architecture for essentially an n-tier collaborative application (not enterprise-class, just a smallish project with potential to grow significantly) where I'm already trying to discipline myself to use IoC and, to some extent, TDD, and I'm wondering, in general terms, whether it is wiser to just hand-code workflow logic or if I should delve into learning and integrating WF4 so that WF becomes literally the controller of the entire application, i.e. the practical C in "MVC" (not ASP.NET MVC but rather the pattern). So should workflow activities in WF4 be the primary controller for a highly expandable/growable web-based collaborative application? Or am I asking entirely the wrong question? This is a vague question, I'm sure, so abstract answers are as welcome as specific ones.

    Read the article

  • Optimal Serialization of Primitive Types

    - by Greg Dean
    We are beginning to roll out more and more WAN deployments of our product (.Net fat client w/ IIS hosted Remoting backend). Because of this we are trying to reduce the size of the data on the wire. We have overridden the default serialization by implementing ISerializable (similar to this), we are seeing anywhere from 12% to 50% gains. Most of our efforts focus on optimizing arrays of primitive types. I would like to know if anyone knows of any fancy way of serializing primitive types, beyond the obvious? For example today we serialize an array of ints as follows: [4-bytes (array length)][4-bytes][4-bytes] Can anyone do significantly better? The most obvious example of a significant improvement, for boolean arrays, is putting 8 bools in each byte, which we already do. Note: Saving 7 bits per bool may seem like a waste of time, but when you are dealing with large magnitudes of data (which we are), it adds up very fast. Note: We want to avoid general compression algorithms because of the latency associated with it. Remoting only supports buffered requests/responses(no chunked encoding). I realize there is a fine line between compression and optimal serialization, but our tests indicate we can afford very specific serialization optimizations at very little cost in latency. Whereas reprocessing the entire buffered response into new compressed buffer is too expensive.

    Read the article

  • What Algorithm will Find New Longtail Keywords for *keyword* in PPC

    - by Becci
    I am looking for the algorithm (or combo) that would allow someone to find new longtail PPC search phrases based on say one corekeyword. Eg #1 word word corekeyword eg #2 word corekeyword word Google search tool allows a limited number vertically - mostly of eg#1 (https://adwords.google.com.au/select/KeywordToolExternal) I also know of other PPC apps that allow more volume than google adwords keyword tool, But I want to find other combos that mention the corekeyword & then naturally sort for the highest volume searched. Working example of exact match: corekeyword: copywriter (40,500 searches a month) google will serve up: become a copywriter (480 searches globally/month in english) But if I specifically look up: How to become a copywriter (720 searches a month) This exact longtail keyword phrase has 300 more searches than the 3 word version spat out by google. I want the algorithm to find any other highly search exact longtials like: how to become a copywriter Simply because it was save significant $ finding other longtail keywords after your campaign has been running an made google lots of money. I don't want a concantenation algorithm (I already have one of those), because hypothetically, I don't know what keywords will be that I want to find. Any gurus out there? Becci

    Read the article

  • StackOverFlowException - but oviously NO recursion/endless loop

    - by user567706
    Hi there, I'm now blocked by this problem the entire day, read thousands of google results, but nothing seems to reflect my problem or even come near to it... i hope any of you has a push into the right direction for me. I wrote a client-server-application (so more like 2 applications) - the client collects data about his system, as well as a screenshot, serializes all this into a XML stream (the picture as a byte[]-array]) and sends this to the server in regular intervals. The server receives the stream (via tcp), deserializes the xml to an information-object and shows the information on a windows form. This process is running stable for about 20-25 minutes at a submission interval of 3 seconds. When observing the memory usage there's nothing significant to see, also kinda stable. But after these 20-25 mins the server throws a StackOverflowException at the point where it deserializes the tcp-stream, especially when setting the Image property from the byte[]-array. I thoroughly searched for recursive or endless loops, and regarding the fact that it occurs after thousands of sucessfull intervals, i could hardly imagine that. public byte[] ImageBase { get { MemoryStream ms = new MemoryStream(); _screen.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); return ms.GetBuffer(); } set { if (_screen != null) _screen.Dispose(); //preventing well-known image memory leak MemoryStream ms = new MemoryStream(value); try { _screen = Image.FromStream(ms); //<< EXCEPTION THROWING HERE } catch (StackOverflowException ex) //thx to new CLR management this wont work anymore -.- { Console.WriteLine(ex.Message + Environment.NewLine + ex.StackTrace); } ms.Dispose(); ms = null; } } I hope that more code would be unnecessary, or it could get very complex... Please help, i have no clue at all anymore thx Chris

    Read the article

  • SQL CE: Limiting rows returned in the query

    - by Diakonia7
    In SQL Compact Edition 3.5 , note that it is the Compact Edition I am talking about- Is there a way to limit the amount of rows to only 2? Something like using LIMIT or TOP. I really don't want to use anything with a SqlCEDataReader, or SqlCEResultSet. I want to do all the limiting in the query. Is this possible now? I have looked around and it doesn't seem so. EDIT- In response to Dave Swersky's request for data and using Min()/Max() on some columns as a means to get the top 2 lines, here is some sample (sterilized) data: Line Site Function Status 1010 Las Vegas new 4 1020 DC send 1 1030 Portland copy 1 1040 SF copy 1 1050 Portland copy 1 1060 DC send 1 *There are more columns than this but these are the significant ones. Sorry for the lack of intuitive data (but the actual data is even less intuitive!), but for security i need to change the data. So- i need to determine: what site the record was at in the preceding line to determine where it needs to be picked up. The site on any given line (except the first line with function = 'new') corresponds to where the item is going next. So simply grabbing that site off the same line wont tell me where it came from. The status will always be 1 or 4. The 4 corresponds to a where it has been delivered already and so i dont want to include those records in the result. But it might be useful in getting the pickup site. For this table of data i want the query to return the site corresponding to the line just above the first line with status 1. So- for this it would be Las Vegas.

    Read the article

  • Am I under risk of CSRF attacks in a POST form that doesn't require the user to be logged in?

    - by Monika Sulik
    I'm probably being a total noob here, but I'm still uncertain about what a CSRF (Cross-Site Request Forgery) attack is exactly. So lets look at three situations... 1) I have a POST form that I use to edit data on my site. I want this data to be edited only by users that are logged in. 2) I have a site, which can be used by both users who are logged in as well as guests. Parts of the site are for logged in users only, but there are also POST forms that can be used by all users - anonymous and not (for example a standard contact form). Should the contact form be safeguarded against CSRF attacks? 3) I have a site which doesn't have an authentication system at all (well, perhaps that's unrealistic, so lets say it has an admin site which is separate from the rest of it and the admin part is properly safeguarded). The main part of the site is only used by anonymous users. Do the POST forms on it need to be safeguarded? In the case of 1) the answer is clearly yes. But in the case of 2 and 3 I don't know (and is the difference between 2 and 3 even significant?).

    Read the article

  • .NET Membership with Repository Pattern

    - by Zac
    My team is in the process of designing a domain model which will hide various different data sources behind a unified repository abstraction. One of the main drivers for this approach is the very high probability that these data sources will undergo significant change in the near future and we don't want to be re-writing business logic when this happens. One data source will be our membership database which was originally implemented using the default ASP.Net Membership Provider. The membership provider is tied to the System.Web.Security namespace but we have a design guideline requiring that our domain model layer is not dependent upon System.Web (or any other implementation/environment dependency) as it will be consumed in different environments - nor do we want our websites directly communicating with databases. I am considering what would be a good approach to reconciling the MembershipProvider approach with our abstracted n-tier architecture. My initial feeling is that we could create a "DomainMembershipProvider" which interacts with the domain model and then implement objects in the model which deal with the repository and handle validation/business logic. The repository would then implement data access using our (as-yet undecided) ORM/data access tool. Are there are any glaring holes in this approach - I haven't worked closely with the MembershipProvider class so may well be missing something. Alternatively, is there an approach that you think will better serve the requirements I described above? Thanks in advance for your thoughts and advice. Regards, Zac

    Read the article

  • How can I improve my real-time behavior in multi-threaded app using pthreads and condition variables

    - by WilliamKF
    I have a multi-threaded application that is using pthreads. I have a mutex() lock and condition variables(). There are two threads, one thread is producing data for the second thread, a worker, which is trying to process the produced data in a real time fashion such that one chuck is processed as close to the elapsing of a fixed time period as possible. This works pretty well, however, occasionally when the producer thread releases the condition upon which the worker is waiting, a delay of up to almost a whole second is seen before the worker thread gets control and executes again. I know this because right before the producer releases the condition upon which the worker is waiting, it does a chuck of processing for the worker if it is time to process another chuck, then immediately upon receiving the condition in the worker thread, it also does a chuck of processing if it is time to process another chuck. In this later case, I am seeing that I am late processing the chuck many times. I'd like to eliminate this lost efficiency and do what I can to keep the chucks ticking away as close to possible to the desired frequency. Is there anything I can do to reduce the delay between the release condition from the producer and the detection that that condition is released such that the worker resumes processing? For example, would it help for the producer to call something to force itself to be context switched out? Bottom line is the worker has to wait each time it asks the producer to create work for itself so that the producer can muck with the worker's data structures before telling the worker it is ready to run in parallel again. This period of exclusive access by the producer is meant to be short, but during this period, I am also checking for real-time work to be done by the producer on behalf of the worker while the producer has exclusive access. Somehow my hand off back to running in parallel again results in significant delay occasionally that I would like to avoid. Please suggest how this might be best accomplished.

    Read the article

  • C++ .NET DLL vs C# Managed Code ? (File Encrypting AES-128+XTS)

    - by Ranhiru
    I need to create a Windows Mobile Application (WinMo 6.x - C#) which is used to encrypt/decrypt files. However it is my duty to write the encryption algorithm which is AES-128 along with XTS as the mode of operation. RijndaelManaged just doesn't cut it :( Very much slower than DES and 3DES CryptoServiceProviders :O I know it all depends on how good I am at writing the algorithm in the most efficient way. (And yes I my self have to write it from scratch but i can take a look @ other implementations) Nevertheless, does writing a C++ .NET DLL to create the encryption/decryption algorithm + all the file handling and using it from C# have a significant performance advantage OVER writing the encryption algorithm + file handling in completely managed C# code? If I use C++ .NET to create the encryption algorithm, should I use MFC Smart Device DLL or ATL? What is the difference and is there any impact on which one I choose? And can i just add a reference to the C++ DLL from C# or should I use P/Invoke? I am fairly competent with C# than C++ but performance plays a major role as I have convinced my lecturers that AES is a very efficient cryptographic algorithm for resource constrained devices. Thanx a bunch :)

    Read the article

  • iPhone Landscape FAQ and Solutions

    - by Johannes Rudolph
    There has been a lot of confusion and a set of corresponding set of questions here on SO how iPhone applications with proper handling for Landscape/Portrait mode autorotation can be implemented. It is especially difficult to implement such an application when starting in landscape mode is desired. The most common observed effect are scrambled layouts and areas of the screen where touches are no longer recognized. A simple search for questions tagged iphone and landscape reveals these issues, which occur under certain scenarios: Landscape only iPhone app with multiple nibs: App started in Landscape mode, view from first nib is rendered fine, everything view loaded from a different nib is not displayed correctly. Iphone Landscape mode switching to Portraite mode on loading new controller: Self explanatory iPhone: In landscape-only, after first addSubview, UITableViewController doesn’t rotate properly: Same issue as above. iPhone Landscape-Only Utility-Template Application: Layout errors, controller does not seem to recognize the view should be rotated but displays a clipped portrait view in landscape mode, causing half of the screen to stay blank. presentModalViewController in landscape after portrait viewController: Modal views are not correctly rendered either. A set of different solutions have been presented, some of them including completely custom animation via CoreGraphics, while others build on the observation that the first view controller loaded from the main nib is always displayed correct. I have spent a significant amount of time investigating this issue and finally found a solution that is not only a partial solution but should work under all these circumstances. It is my intend with this CW post to provide sort of a FAQ for others having issues with UIViewControllers in Landscape mode. Please provide feedback and help improve the quality of this Post by incorporating any related observations. Feel free to edit and post other/better answers if you know of any.

    Read the article

  • SQL deadlock on delete then bulk insert

    - by StarLite
    I have an issue with a deadlock in SQL Server that I haven't been able to resolve. Basically I have a large number of concurrent connections (from many machines) that are executing transactions where they first delete a range of entries and then re-insert entries within the same range with a bulk insert. Essentially, the transaction looks like this BEGIN TRANSACTION T1 DELETE FROM [TableName] WITH( XLOCK HOLDLOCK ) WHERE [Id]=@Id AND [SubId]=@SubId INSERT BULK [TableName] ( [Id] Int , [SubId] Int , [Text] VarChar(max) COLLATE SQL_Latin1_General_CP1_CI_AS ) WITH(CHECK_CONSTRAINTS, FIRE_TRIGGERS) COMMIT TRANSACTION T1 The bulk insert only inserts items matching the Id and SubId of the deletion in the same transaction. Furthermore, these Id and SubId entries should never overlap. When I have enough concurrent transaction of this form, I start to see a significant number of deadlocks between these statements. I added the locking hints XLOCK HOLDLOCK to attempt to deal with the issue, but they don't seem to be helpling. The canonical deadlock graph for this error shows: Connection 1: Holds RangeX-X on PK_TableName Holds IX Page lock on the table Requesting X Page lock on the table Connection 2: Holds IX Page lock on the table Requests RangeX-X lock on the table What do I need to do in order to ensure that these deadlocks don't occur. I have been doing some reading on the RangeX-X locks and I'm not sure I fully understand what is going on with these. Do I have any options short of locking the entire table here?

    Read the article

< Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >