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  • Is it possible to load an entire SQL Server CE database into RAM?

    - by DanM
    I'm using LinqToSql to query a small SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table via a foreign key, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of the appeal of LinqToSql. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view.

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  • FileNotFoundExcecption while inserting image into SDCard.

    - by Are
    Hi, I want to insert images into my SDCard.So I used below code m_cImagePath = "/sdcard/"+ String.format("%d.jpg", System.currentTimeMillis()); FileOutputStream lObjOutStream = null; try { lObjOutStream = new FileOutputStream(m_cImagePath); if (null != lObjOutStream && null != finalBitmap) { finalBitmap.compress(Bitmap.CompressFormat.JPEG, 85, lObjOutStream); lObjOutStream.close(); }catch(FileNotFoundException fe){ fe.printStackTrace(); } Sometimes it is giving FileNotFoundException even my SDCard had memory.When I remove some images from sdcard again it is working smoothly.Why this Happend?How can i know that file is inserted successfully in SDCard and Is there any functionality in Java1.5 to know available space of the SDCard like java 1.6?How can i know file length which is not before inserting into the SDCard(I searched in google and found that "when the file is not physically there then file.length() always gives 0" ).But before inserting i want to know the length of the file.Then Comparing this space to available SDCard space is simple. Note :I had an idea to use Unix command df sdcard using in Runtime class to found SDCard space. Please give me an idea in this problem. Regards, Android Developer

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  • Sequence Point and Evaluation Order( Preincrement)

    - by Josh
    There was a debate today among some of my colleagues and I wanted to clarify it. It is about the evaluation order and the sequence point in an expression. It is clearly stated in the standard that C/C++ does not have a left-to-right evaluation in an expression unlike languages like Java which is guaranteed to have a sequencial left-to-right order. So, in the below expression, the evaluation of the leftmost operand(B) in the binary operation is sequenced before the evaluation of the rightmost operand(C): A = B B_OP C The following expression according, to CPPReference under the subsection Sequenced-before rules(Undefined Behaviour) and Bjarne's TCPPL 3rd ed, is an UB x = x++ + 1; It could be interpreted as the compilers like BUT the expression below is said to be clearly a well defined behaviour in C++11 x = ++x + 1; So, if the above expression is well defined, what is the "fate" of this? array[x] = ++x; It seems the evaluation of a post-increment and post-decrement is not defined but the pre-increment and the pre-decrement is defined. NOTE: This is not used in a real-life code. Clang 3.4 and GCC 4.8 clearly warns about both the pre- and post-increment sequence point.

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  • Stop SQL returning the same result twice in a JOIN

    - by nbs189
    I have joined together several tables to get data i want but since I am new to SQL i can't figure out how to stop data being returned more than once. her's the SQL statement; SELECT T.url, T.ID, S.status, S.ID, E.action, E.ID, E.timestamp FROM tracks T, status S, events E WHERE S.ID AND T.ID = E.ID ORDER BY E.timestamp DESC The data that is returned is something like this; +----------------------------------------------------------------+ | URL | ID | Status | ID | action | ID | timestamp | +----------------------------------------------------------------+ | T.1 | 4 | hello | 4 | has uploaded a track | 4 | time | | T.2 | 3 | bye | 3 | has some news | 3 | time | | t.1 | 4 | more | 4 | has some news | 4 | time | +----------------------------------------------------------------+ That's a very basic example but does outline what happens. If you look at the third row the URL is repeated when there is a different status. This is what I want to happen; +-------------------------------------------------------+ | URL or Status | ID | action | timestamp | +-------------------------------------------------------+ | T.1 | 4 | has uploaded a track | time | | hello | 3 | has some news | time | | bye | 4 | has some news | time | +-------------------------------------------------------+ Please notice that the the url (in this case the mock one is T.1) is shown when the action is has uploaded a track. This is very important. The action in the events table is inserted on trigger of a status or track insert. If a new track is inserted the action is 'has uploaded a track' and you guess what it is for a status. The ID and timestamp is also inserted into the events table at this point. Note: There are more tables that go into the query, 3 more in fact, but I have left them out for simplicity.

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  • mailing system DB structure, need help

    - by Anna
    i have a system there user(sender) can write a note to friends(receivers), number of receivers=0. Text of the message is saved in DB and visible to sender and all receivers then they login to system. Sender can add more receivers at any time. More over any of receivers can edit the message and even remove it from DB. For this system i created 3 tables, shortly: users(userID, username, password) messages(messageID, text) list(id, senderID, receiverID, messageID) in table "list" each row corresponds to pair sender-receiver, like sender_x_ID -- receiver_1_ID -- message_1_ID sender_x_ID -- receiver_2_ID -- message_1_ID sender_x_ID -- receiver_3_ID -- message_1_ID Now the problem is: 1. if user deletes the message from table "messages" how to automatically delete all rows from table "list" which correspond to deleted message. Do i have to include some foreign keys? More important: 2. if sender has let say 3 receivers for his message1 (username1, username2 and username3) and at certain moment decides to add username4 and username5 and at the same time exclude username1 from the list of receivers. PHP code will get the new list of receivers (username2, username3, username4, username5) That means insert to table "list" sender_x_ID -- receiver_4_ID -- message_1_ID sender_x_ID -- receiver_5_ID -- message_1_ID and also delete from table "list" the row corresponding to user1 (which is not in the list or receivers any more) sender_x_ID -- receiver_1_ID -- message_1_ID which sql query to send from PHP to make it in an easy and intelligent way? Please help! Examples of sql queries would be perfect!

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  • What is the best way to wait for a GPS location fix?

    - by qtips
    Hi, Using my Android application, when a user does a certain action, a background service is started that fetches the current GPS location and saves it in a database in addition of doing some other stuff. In that service, I use the requestLocationUpdates() from the LocationManager class and wait until the onLocationChanged() of my LocationListener (which is implemented by the service) is fired. But what is the best way to wait for the onLocationChanged to fire? Should I simply poll on a variable and wait until it is set? Any tips? Note: I cannot simply write to the database in the onLocationChanged() because of some other stuff. EDIT: To clearfy my situation, I can present an example similar to my case: Let's say user pushes a button and a method myMethod is fired which will return some object. Then, in this myMethod I will register for location updates from the GPS (using requestLocationChanged) and in addition wait for the users location and use it for something. In other words, myMethod cannot return before the location is present. I don't know how I can use onLocationChanged in this case.

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  • SQL to insert latest version of a group of items

    - by Garett
    I’m trying to determine a good way to handle the scenario below. I have the following two database tables, along with sample data. Table1 contains distributions that are grouped per project. A project can have one or more distributions. A distribution can have one of more accounts. An account has a percentage allocated to it. The distributions can be modified by adding or removing account, as well as changing percentages. Table2 tracks distributions, assigning a version number to each distribution. I need to be able to copy new distributions from Table1 to Table2, but only under two conditions: 1. the entire distribution does not already exist 2. the distribution has been modified (accounts added/removed or percentages changed). Note: When copying a distribution from Table1 to Table2 I need to compare all accounts and percentages within the distribution to determine if it already exists. When inserting the new distribution then I need to increment the VersionID (max(VersionID) + 1). So, in the example provided the distribution (12345, 1) has been modified, adding account number 7, as well as changing percentages allocated. The entire distribution should be copied to the second table, incrementing the VersionID to 3 in the process. The database in question is SQL Server 2005. Table1 ------ ProjectID AccountDistributionID AccountID Percent 12345 1 1 25.0 12345 1 2 25.0 12345 1 7 50.0 56789 2 3 25.0 56789 2 4 25.0 56789 2 5 25.0 56789 2 6 25.0 Table2 ------ ID VersionID Project ID AccountDistributionID AccountID Percent 1 1 12345 1 1 50.0 2 1 12345 1 2 50.0 3 2 56789 2 3 25.0 4 2 56789 2 4 25.0 5 2 56789 2 5 25.0 6 2 56789 2 6 25.0

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  • How can I create a rules engine without using eval() or exec()?

    - by Angela
    I have a simple rules/conditions table in my database which is used to generate alerts for one of our systems. I want to create a rules engine or a domain specific language. A simple rule stored in this table would be..(omitting the relationships here) if temp > 40 send email Please note there would be many more such rules. A script runs once daily to evaluate these rules and perform the necessary actions. At the beginning, there was only one rule, so we had the script in place to only support that rule. However we now need to make it more scalable to support different conditions/rules. I have looked into rules engines , but I hope to achieve this in some simple pythonic way. At the moment, I have only come up with eval/exec and I know that is not the most recommended approach. So, what would be the best way to accomplish this?? ( The rules are stored as data in database so each object like "temperature", condition like "/=..etc" , value like "40,50..etc" and action like "email, sms, etc.." are stored in the database, i retrieve this to form the condition...if temp 50 send email, that was my idea to then use exec or eval on them to make it live code..but not sure if this is the right approach )

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  • Which CSS identifier is used for the selected tab in tabbed tables in browsers other than IE?

    - by David Navarre
    When you have a table on a form in Notes, you can choose to display only one row at a time (via the Special Table Row Display parameter on the Table Rows tab of the Table properties). In a Notes document displayed using Internet Explorer that contains such a table, a row is displayed with a cell for each "tab". The TD that serves as the tab for the selected "Notes table row" is assigned <td class="dominoSelTopTab">, while the other tabs get <td class="dominoTopTab">. However, when using other browsers, it's not nearly as simple. In Firefox, each "tab" ends up as a single-celled-single-row-table within the table with very little to identify it. <td><table border="1" cellpadding="2"> <tr><td><div align="center"><b>Tab 2</b></div></td></tr> </table></td> A non-selected tab would show as follows: <td><table border="1" cellpadding="2"> <tr><td><div align="center"><a name="1." href="/Projects/MyCSS.nsf/0c3b9489476440c085257a62006d97d6/d482a1767a4af77f85257a62006db064?OpenDocument&amp;TableRow=1.0#1." target="_self">Tab 1</a></div></td></tr> </table></td> So, the question is, how do I identify the selected tabs and the non-selected tabs when not using IE? Note: For those who are not Notes developers, the HTML is auto-generated from the visual design as laid out in the Notes designer client. I would replace it all with manual HTML, except there is so much of it that doing so would consume far too much time.

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  • Which pattern to use for logging? Dependency Injection or Service Locator?

    - by andlju
    Consider this scenario. I have some business logic that now and then will be required to write to a log. interface ILogger { void Log(string stuff); } interface IDependency { string GetInfo(); } class MyBusinessObject { private IDependency _dependency; public MyBusinessObject(IDependency dependency) { _dependency = dependency; } public string DoSomething(string input) { // Process input var info = _dependency.GetInfo(); var intermediateResult = PerformInterestingStuff(input, info); if (intermediateResult== "SomethingWeNeedToLog") { // How do I get to the ILogger-interface? } var result = PerformSomethingElse(intermediateResult); return result; } } How would you get the ILogger interface? I see two main possibilities; Pass it using Dependency Injection on the constructor. Get it via a singleton Service Locator. Which method would you prefer, and why? Or is there an even better pattern? Update: Note that I don't need to log ALL method calls. I only want to log a few (rare) events that may or may not occur within my method.

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  • Linear Interpolation. How to implement this algorithm in C ? (Python version is given)

    - by psihodelia
    There exists one very good linear interpolation method. It performs linear interpolation requiring at most one multiply per output sample. I found its description in a third edition of Understanding DSP by Lyons. This method involves a special hold buffer. Given a number of samples to be inserted between any two input samples, it produces output points using linear interpolation. Here, I have rewritten this algorithm using Python: temp1, temp2 = 0, 0 iL = 1.0 / L for i in x: hold = [i-temp1] * L temp1 = i for j in hold: temp2 += j y.append(temp2 *iL) where x contains input samples, L is a number of points to be inserted, y will contain output samples. My question is how to implement such algorithm in ANSI C in a most effective way, e.g. is it possible to avoid the second loop? NOTE: presented Python code is just to understand how this algorithm works. UPDATE: here is an example how it works in Python: x=[] y=[] hold=[] num_points=20 points_inbetween = 2 temp1,temp2=0,0 for i in range(num_points): x.append( sin(i*2.0*pi * 0.1) ) L = points_inbetween iL = 1.0/L for i in x: hold = [i-temp1] * L temp1 = i for j in hold: temp2 += j y.append(temp2 * iL) Let's say x=[.... 10, 20, 30 ....]. Then, if L=1, it will produce [... 10, 15, 20, 25, 30 ...]

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  • How to delete ProgIDs from other user accounts when uninstalling from Windows?

    - by Mordachai
    I've been investigating "how should a modern windows c++ application register its file types" with Windows (see http://stackoverflow.com/questions/2828637/c-how-do-i-correctly-register-and-unregister-file-type-associations-for-our-ap). And having combed through the various MSDN articles on the subject, the summary appears to be as follows: The installer (elevated) should register the global ProgID HKLM\Software\Classes\my-app.my-doc[.version] (e.g. HKLM\Software\Classes\TextPad.text) The installer also configures default associations for its document types (e.g. .myext) and points this to the aforementioned global ProgID in HKLM. NOTE: a user interface should be provided here to allow the user to either accept all default associations, or to customize which associations should be set. The application, running standard (unelevated), should provide a UI for allowing the current user to set their personal associations as is available in the installer, except that these associations are stored in HKCU\Software\Classes (per user, not per machine). The UN-installer is then responsible for deleting all registered ProgIDs (but should leave the actual file associations alone, as Windows is smart enough to handle associations pointing to missing ProgIDs, and this is the specified desired behavior by MSDN). So that schema sounds reasonable to me, except when I consider #4: How does an uninstaller, running elevated for a given user account, delete any per-user ProgIDs created in step #3 for other users? As I understand things, even in elevated mode, an uninstaller cannot go into another user's registry hive and delete items? Or can it? Does it have to load each given user hive first? What are the rules here? Thanks for any insight you might have to offer! EDIT: See below for the solution (My question was founded in confusion)

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  • multiple models in Rails with a shared interface

    - by dfondente
    I'm not sure of the best structure for a particular situation in Rails. We have several types of workshops. The administration of the workshops is the same regardless of workshop type, so the data for the workshops is in a single model. We collect feedback from participants about the workshops, and the questionnaire is different for each type of workshop. I want to access the feedback about the workshop from the workshop model, but the class of the associated model will depend on the type of workshop. If I was doing this in something other than Rails, I would set up an abstract class for WorkshopFeedback, and then have subclasses for each type of workshop: WorkshopFeedbackOne, WorkshopFeedbackTwo, WorkshopFeedbackThree. I'm unsure how to best handle this with Rails. I currently have: class Workshop < ActiveRecord::Base has_many :workshop_feedbacks end class Feedback < ActiveRecord::Base belongs_to :workshop has_many :feedback_ones has_many :feedback_twos has_many :feedback_threes end class FeedbackOne < ActiveRecord::Base belongs_to :feedback end class FeedbackTwo < ActiveRecord::Base belongs_to :feedback end class FeedbackThree < ActiveRecord::Base belongs_to :feedback end This doesn't seem like to the cleanest way to access the feedback from the workshop model, as accessing the correct feedback will require logic investigating the Workshop type and then choosing, for instance, @workshop.feedback.feedback_one. Is there a better way to handle this situation? Would it be better to use a polymorphic association for feedback? Or maybe using a Module or Mixin for the shared Feedback interface? Note: I am avoiding using Single Table Inheritance here because the FeedbackOne, FeedbackTwo, FeedbackThree models do not share much common data, so I would end up with a large sparsely populated table with STI.

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  • How do I set an og:type for the first time without losing likes?

    - by Travis
    When I first created my site, I neglected to add the Open Graph tags that Facebook recommends (http://developers.facebook.com/docs/opengraph/), and the site now has about 1200 Facebook likes through a fb:comments widget. http://graph.facebook.com/http://feedtheanimalssamples.com/ shows this: { "id": "http://feedtheanimalssamples.com/", "shares": 1204 } Recently, I've added added the following OG tags: <meta property="fb:app_id" content="59193243341" /> <meta property="og:title" content="Girl Talk - Feed The Animals Samples (old)" /> <meta property="og:image" content="http://feedtheanimalssamples.com/fta_small.png" /> <meta property="og:url" content="http://feedtheanimalssamples.com" /> But when I add the og:type tag: <meta property="og:type" content="website" /> and Lint the site, I lose all my likes. http://graph.facebook.com/http://feedtheanimalssamples.com/ starts showing this: { "id": "170545342993850", "name": "Girl Talk - Feed The Animals Samples", "picture": "http://profile.ak.fbcdn.net/hprofile-ak-snc4/188039_170545342993850_3277642_s.jpg", "link": "http://www.facebook.com/pages/Girl-Talk-Feed-The-Animals-Samples/170545342993850", "category": "Website", "website": "http://feedtheanimalssamples.com/", "description": "Interactively identifies the samples in the 2008 album 'Feed The Animals' by mashup artist Girl Talk.", "likes": 1 } (Note the "likes": 1.) So: How do I set the og:type without losing my likes? I'm trying to let my likers know that I've created a new and improved site. I'm following the instuctions at http://developers.facebook.com/blog/post/397 under "Publishing to Connected Users via Graph API", but using that API apparently requires specifying an og:type. Thanks!

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  • JSON onFailure issue

    - by Mikey1980
    I’m having trouble getting a AJAX/JSON function to work correctly. I had this function grabbing value from a drop down box but now I want to use an anchor tag to set it's value. I thought it would be easy to just use the onClick event to pass string to the function I was using for the drop down box but I get the alert in JSON onFailure event even though data gets added to MySQL. I tried removing the alert from onFailure event but then it doesn't add the data. The drop down still continues work work fine, no alerts. (I should note that removing the alert also broke my drop down box) 1st I add an onClick event… <a href="<?php echo Settings::get('app.webroot'); ?>?view=schedule&action=questions" onmouseout="MM_swapImgRestore();" onmouseover="MM_swapImage('bre','','template/images/schedule/bre_f2.gif',1)" onclick="assignCallType('testing')";> 2nd I check main.js.php function assignCallType(type) { alert(type); new Request.JSON({ url: "ajax.php", onSuccess: function(rtndata,txt){ if (rtndata['STATUS'] != 'OK') alert('Status was not okay'); }, onFailure : function () { alert("onFailure") } }).get({ 'action': 'assignCallType', 'call_type': type }); } 3rd Ajax.php: the variable is back in PHP and values get added to MySQL but I get the Alert in the JSON onFailure event if ($_GET['action'] == "assignCallType") { if ($USER->isInsideSales()) { $call_type = $_GET['call_type']; $_SESSION['callinfo']->setCallType($call_type); $_SESSION['callinfo']->save($callid); echo json_encode(array('STATUS'=>'OK')); } else { echo json_encode(array('STATUS'=>'DENIED')); } } Any idea where I am going wrong. The only difference between this and the working drop down is how the function was called, I used onchange="assignCallType(this.value)".

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  • Expose webservice directly to webclients or keep a thin server-side script layer in between?

    - by max
    Hi, I'm developing a REST webservice (Java, Jersey). The people I'm doing this for want to directly access the webservice via Javascript. Some instinct tells me this is not a good idea, but I cannot really explain that instinct. My natural approach would have been to have the webservice do the real logic and database access, but also have some (relatively thin) server-side script layer (e.g. in PHP). Clients would talk to the PHP layer which in turn would talk to the webservice. (The webservice would be pretty local to the apache/PHP server and implicitly trust calls from the script layer. The script layer would take care of session management.) (Btw, I am not talking about just hiding the webservice behind an Apache which simply redirects calls.) But as I find myself at a lack of words/arguments to explain my instinct, I wonder whether my instinct is right - note that while I have been developing all kinds of software in all kinds of languages and frameworks for like 17 years, this is the first time I develop a webservice. So my question is basically: what are your opinions? Are there any standard setups? Is my instinct totally wrong? Or partially? ;P Many thanks, Max PS: I might add a few bits of information about the planned usage of the whole application: will be accessed by different kinds of users, partly general public, partly privileged thus, all major OS/browser combinations can be expected as clients however, writing the client is not my responsibility will potentially have very high load/traffic logic of webservice will later be massively expanded for another product which is basically a superset of the functionality of the current project there is a significant likelihood that at some point an API should be exposed which can be used by 3rd party developers - obviously, with some restrictions at some point, the public view of the product should become accessible via smartphones, too (in other words, maybe a customized version of the site to adapt to the smaller display and different input methods)

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  • What should a teen dev do for practical experience in development?

    - by aviraldg
    What should a teen dev do for practical experience? If you want more details , then read on: I learnt programming when I was 9 , with GWBASIC (which I now hate) , which was what was taught @ school. That was done in a month. After that I learnt C++ and relearnt it (as I didn't know of templates and the STL before that) Recently I learnt PHP , SQL and Python. This was around the time I switched over to Ubuntu. I'd always loved the "GNUish" style of software development so I jumped right in. However , most of the projects that I found required extensive knowledge of their existing codebase. So , right now I'm this guy who knows a couple of languages and has written a couple of small programs ... but hasn't gone "big", if you get it. I would love suggestions of projects that are informal and small to medium sized , and do not require much knowledge of the codebase. Also note that I've looked at things like Google Summer of Code and sites like savannah.gnu.org and the first doesn't apply , since I'm still in school and the latter either has infeasable projects , or things that are too hard.

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  • crash when using stl vector at instead of operator[]

    - by Jamie Cook
    I have a method as follows (from a class than implements TBB task interface - not currently multithreading though) My problem is that two ways of accessing a vector are causing quite different behaviour - one works and the other causes the entire program to bomb out quite spectacularly (this is a plugin and normally a crash will be caught by the host - but this one takes out the host program as well! As I said quite spectacular) void PtBranchAndBoundIterationOriginRunner::runOrigin(int origin, int time) const // NOTE: const method { BOOST_FOREACH(int accessMode, m_props->GetAccessModes()) { // get a const reference to appropriate vector from member variable // map<int, vector<double>> m_rowTotalsByAccessMode; const vector<double>& rowTotalsForAccessMode = m_rowTotalsByAccessMode.find(accessMode)->second; if (origin != 129) continue; // Additional debug constrain: I know that the vector only has one non-zero element at index 129 m_job->Write("size: " + ToString(rowTotalsForAccessMode.size())); try { // check for early return... i.e. nothing to do for this origin if (!rowTotalsForAccessMode[origin]) continue; // <- this works if (!rowTotalsForAccessMode.at(origin)) continue; // <- this crashes } catch (...) { m_job->Write("Caught an exception"); // but its not an exception } // do some other stuff } } I hate not putting in well defined questions but at the moment my best phrasing is : "WTF?" I'm compiling this with Intel C++ 11.0.074 [IA-32] using Microsoft (R) Visual Studio Version 9.0.21022.8 and my implementation of vector has const_reference operator[](size_type _Pos) const { // subscript nonmutable sequence #if _HAS_ITERATOR_DEBUGGING if (size() <= _Pos) { _DEBUG_ERROR("vector subscript out of range"); _SCL_SECURE_OUT_OF_RANGE; } #endif /* _HAS_ITERATOR_DEBUGGING */ _SCL_SECURE_VALIDATE_RANGE(_Pos < size()); return (*(_Myfirst + _Pos)); } (Iterator debugging is off - I'm pretty sure) and const_reference at(size_type _Pos) const { // subscript nonmutable sequence with checking if (size() <= _Pos) _Xran(); return (*(begin() + _Pos)); } So the only difference I can see is that at calls begin instead of simply using _Myfirst - but how could that possibly be causing such a huge difference in behaviour?

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  • Is it safe to use a boolean flag to stop a thread from running in C#

    - by Lirik
    My main concern is with the boolean flag... is it safe to use it without any synchronization? I've read in several places that it's atomic. class MyTask { private ManualResetEvent startSignal; private CountDownLatch latch; private bool running; MyTask(CountDownLatch latch) { running = false; this.latch = latch; startSignal = new ManualResetEvent(false); } // A method which runs in a thread public void Run() { startSignal.WaitOne(); while(running) { startSignal.WaitOne(); //... some code } latch.Signal(); } public void Stop() { running = false; startSignal.Set(); } public void Start() { running = true; startSignal.Set(); } public void Pause() { startSignal.Reset(); } public void Resume() { startSignal.Set(); } } Is this a safe way to design a task? Any suggestions, improvements, comments? Note: I wrote my custom CountDownLatch class in case you're wondering where I'm getting it from.

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  • Visual Studio internal project references not always working

    - by Chris
    I am using Visual Studio and a solution with 10 or so projects in (mostly VB, some C#) which have various dependencies set up. Usually when I compile the solution it works fine. Occasionally when I do it I get a build error saying that one of the projects referenced is the wrong version (I think always the same one, possibly may be two that can cause problems). In this case going to the solution explorer and right clicking on the mentioned project and saying "rebuild" followed by another full build makes it work fine. I assume there is something set up wrong somewhere but I didn't set up the solution myself initially and a quick look through doesn't show anything immediately wrong. It feels like there is some kind of race condition, that VS is internally setting the version number of the project it needs before that project has been rebuilt and thus gets it wrong or something like that but I'm sure VS should handle all this sort of thing properly. Can anybody please suggest places that I could check for whether this has been correctly set up... And I should finally note that since I don't have reliable repro of this I may not be able to respond to questions too quickly. For example the obvious one of "Could you give the exact error message" will have to wait since I didn't think to copy it this morning, it was only after I cleared it up with the above steps that I thought to post here. Similarly any solutions may take a while to confirm.

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  • inconsistent setTexture behavior in cocos2d on iPhone after using CCAnimate/CCAnimation

    - by chillid
    Hi, I have a character that goes through multiple states. The state changes are reflected by means of a sprite image (texture) change. The state change is triggered by a user tapping on the sprite. This works consistently and quite well. I then added an animation during State0. Now, when the user taps - setTexture gets executed to change the texture to reflect State1, however some of the times (unpredictable) it does not change the texture. The code flows as below: // 1. // Create the animation sequence CGRect frame1Rect = CGRectMake(0,32,32,32); CGRect frame2Rect = CGRectMake(32,32,32,32); CCTexture2D* texWithAnimation = [[CCTextureCache sharedTextureCache] addImage:@"Frames0_1_thinkNthickoutline32x32.png"]; id anim = [[[CCAnimation alloc] initWithName:@"Sports" delay:1/25.0] autorelease]; [anim addFrame:[CCSpriteFrame frameWithTexture:texWithAnimation rect:frame1Rect offset:ccp(0,0)]]; [anim addFrame:[CCSpriteFrame frameWithTexture:texWithAnimation rect:frame2Rect offset:ccp(0,0)]]; // Make the animation sequence repeat forever id myAction = [CCAnimate actionWithAnimation: anim restoreOriginalFrame:NO]; // 2. // Run the animation: sports = [[CCRepeatForever alloc] init]; [sports initWithAction:myAction]; [self.sprite runAction:sports]; // 3. stop action on state change and change texture: NSLog(@"Stopping action"); [sprite stopAction:sports]; NSLog(@"Changing texture for kCJSports"); [self setTexture: [[CCTextureCache sharedTextureCache] addImage:@"SportsOpen.png"]]; [self setTextureRect:CGRectMake(0,0,32,64)]; NSLog(@"Changed texture for kCJSports"); Note that all the NSLog lines get logged - and the texture RECT changes - but the image/texture changes only some of the times - fails for around 10-30% of times. Locking/threading/timing issue somewhere? My app (game) is single threaded and I only use the addImage and not the Async version. Any help much appreciated.

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  • PHP/Javascript: Restart Form Button Isn't Working, Code Insde

    - by Josh K
    Basically I want a confirmation box to pop up when they click the button asking if they sure they want to restart, if yes, then it destroys session and takes them to the first page. Heres what i got... echo "<form id=\"form\" name=\"form\" method=\"post\" action=\"nextpage.php\">\n"; echo " <input type=\"button\" name='restart' value='Restart' id='restart' onclick='restartForm()' />"; and for the script... <script type=\"text/javascript\"> <!-- function restartForm() { var answer = confirm('Are you sure you want to start over?'); if (answer) { form.action=\"firstpage.php\"; session_destroy(); form.submit(); } else alert ('Restart Cancelled'); } // -- </script>"; EDIT: Note that pressing the button brings up the confirm box, but if you click okay nothing happens sometimes. Sometimes if u click cancel it still submits the form (To the original action)

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  • Accessing variables with different scope in C++

    - by Portablejim
    With #include <iostream> using namespace std; int a = 1; int main() { int a = 2; if(true) { int a = 3; cout << a << " " << ::a // Can I access a = 2 here? << " " << ::a << endl; } cout << a << " " << ::a << endl; } having the output 3 1 1 2 1 Is there a way to access the 'a' equal to 2 inside the if statement where there is the 'a' equal to 3, with the output 3 2 1 2 1 Note: I know this should not be done (and the code should not get to the point where I need to ask). This question is more "can it be done".

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  • JavaCC: How can I specify which token(s) are expected in certain context?

    - by java.is.for.desktop
    Hello, everyone! I need to make JavaCC aware of a context (current parent token), and depending on that context, expect different token(s) to occur. Consider the following pseudo-code: TOKEN <abc> { "abc*" } // recognizes "abc", "abcd", "abcde", ... TOKEN <abcd> { "abcd*" } // recognizes "abcd", "abcde", "abcdef", ... TOKEN <element1> { "element1" "[" expectOnly(<abc>) "]" } TOKEN <element2> { "element2" "[" expectOnly(<abcd>) "]" } ... So when the generated parser is "inside" a token named "element1" and it encounter "abcdef" it recognizes it as <abc>, but when its "inside" a token named "element2" it recognizes the same string as <abcd>. element1 [ abcdef ] // aha! it can only be <abc> element2 [ abcdef ] // aha! it can only be <abcd> If I'm not wrong, it would behave similar to more complex DTD definitions of an XML file. So, how can one specify, in which "context" which token(s) are valid/expected? NOTE: It would be not enough for my real case to define a kind of "hierarchy" of tokens, so that "abcdef" is always first matched against <abcd> and than <abc>. I really need context-aware tokens.

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  • AngularJS: Using Shared Service(with $resource) to share data between controllers, but how to define callback functions?

    - by shaunlim
    Note: I also posted this question on the AngularJS mailing list here: https://groups.google.com/forum/#!topic/angular/UC8_pZsdn2U Hi All, I'm building my first AngularJS app and am not very familiar with Javascript to begin with so any guidance will be much appreciated :) My App has two controllers, ClientController and CountryController. In CountryController, I'm retrieving a list of countries from a CountryService that uses the $resource object. This works fine, but I want to be able to share the list of countries with the ClientController. After some research, I read that I should use the CountryService to store the data and inject that service into both controllers. This was the code I had before: CountryService: services.factory('CountryService', function($resource) { return $resource('http://localhost:port/restwrapper/client.json', {port: ':8080'}); }); CountryController: //Get list of countries //inherently async query using deferred promise $scope.countries = CountryService.query(function(result){ //preselected first entry as default $scope.selected.country = $scope.countries[0]; }); And after my changes, they look like this: CountryService: services.factory('CountryService', function($resource) { var countryService = {}; var data; var resource = $resource('http://localhost:port/restwrapper/country.json', {port: ':8080'}); var countries = function() { data = resource.query(); return data; } return { getCountries: function() { if(data) { console.log("returning cached data"); return data; } else { console.log("getting countries from server"); return countries(); } } }; }); CountryController: $scope.countries = CountryService.getCountries(function(result){ console.log("i need a callback function here..."); }); The problem is that I used to be able to use the callback function in $resource.query() to preselect a default selection, but now that I've moved the query() call to within my CountryService, I seemed to have lost what. What's the best way to go about solving this problem? Thanks for your help, Shaun

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