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  • new Date() In javascript :: need Help

    - by gskoli
    Dear all, i am creating a digital clock using images & javascript but i want to pass a server time that time ... How to do that ... I am getting time from server and passing it to Date Following i have given snippet . var time_str = document.clock_form.time_str.value ; //alert (time_str); function dotime(){ theTime=setTimeout('dotime();',1000); //d = new Date(Date.parse(time_str)); d= new Date(time_str); hr= d.getHours()+100; mn= d.getMinutes()+100; se= d.getSeconds()+100; var time_str = document.clock_form.time_str.value ; //alert (time_str); alert(' TIME ---> '+hr+' :: '+mn+' :: '+ se); if(hr==100){ hr=112;am_pm='am'; } else if(hr<112){ am_pm='am'; } else if(hr==112){ am_pm='pm'; } else if(hr>112){ am_pm='pm';hr=(hr-12); } tot=''+hr+mn+se; document.hr1.src = '/flash_files/digits/dg'+tot.substring(1,2)+'.gif'; document.hr2.src = '/flash_files/digits/dg'+tot.substring(2,3)+'.gif'; document.mn1.src = '/flash_files/digits/dg'+tot.substring(4,5)+'.gif'; document.mn2.src = '/flash_files/digits/dg'+tot.substring(5,6)+'.gif'; document.se1.src = '/flash_files/digits/dg'+tot.substring(7,8)+'.gif'; document.se2.src = '/flash_files/digits/dg'+tot.substring(8,9)+'.gif'; document.ampm.src= '/flash_files/digits/dg'+am_pm+'.gif'; } dotime(); But it is not working Help me out Thanks in advance.

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  • Image swaping with click on <tr>

    - by Jonny Sooter
    I've edited this piece of code from the Data Tables Plugin witch makes a tr click able and pops open another tr with details from the clicked tr. This piece of code is the event listener for opening and closing. When "details" are open the img should be images/details_close.png and they are closed the img should be images/details_open.png and have a swap occurring when it opens and closes when clicked. What is happening is there is no swap going on when its open or closed I still only get the "details_open.png". I don't knoe if I'm just not selecting the img tag properly or whats going on. Link to project: http://www2.kent.k12.wa.us/ksd/it/www/mobile/elementary.html $('#example tbody').on('click', 'td', function (e) { var myImage = $(this).find("img"); var nTr = $(this).parents('tr')[0]; if ( oTable.fnIsOpen(nTr) ) { /* This row is already open - close it */ myImage.src = "images/details_open.png"; oTable.fnClose( nTr ); } else { /* Open this row */ myImage.src = "images/details_close.png"; oTable.fnOpen( nTr, fnFormatDetails(oTable, nTr), 'details' ); } } );

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  • Using a variable in a mysql query, in a C++ MFC program.

    - by D.Gaughan
    Hi, after extensive trawling of the internet I still havent found any solution for this problem. I`m writing a small C++ app that connects to an online database and outputs the data in a listbox. I need to enable a search function using an edit box, but I cant get the query to work while using a variable. My code is: res = mysql_perform_query (conn, "select distinct artist from Artists"); //res = mysql_perform_query (conn, "select album from Artists where artist = ' ' "); while((row = mysql_fetch_row(res)) != NULL){ CString str; UpdateData(); str = ("%s\n", row[0]); UpdateData(FALSE); m_list_control.AddString(str); } the first "res = " line is working fine, but I need the second one to work. I have a member variable m_search_edit set up for the edit box, but any way I try to include it in the sql statement causes errors. eg. res = mysql_perform_query (conn, "select album from Artists where artist = '"+m_search_edit+" ' "); causes this error: error C2664: 'mysql_perform_query' : cannot convert parameter 2 from 'class CString' to 'char *' No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called" And when I convert m_search_edit to a char* it gives me a " Cannot add 2 pointers" error. Any way around this???

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  • Recursive code Sorting in VB

    - by Peter
    Ages old question: You have 2 hypothetical eggs, and a 100 story building to drop them from. The goal is to have the least number of guaranteed drops that will ensure you can find what floor the eggs break from the fall. You can only break 2 eggs. Using a 14 drop minimum method, I need help writing code that will allow me to calculate the following: Start with first drop attempt on 14th floor. If egg breaks then drop floors 1-13 to find the floor that causes break. ElseIf egg does not break then move up 13 floors to floor number 27 and drop again. If egg breaks then drop floors 15-26 starting on 15 working up to find the floor egg breaks on. ElseIf egg does not break then move up 12 floors to floor number 39 and drop again. etc. etc. The way this increases is as follows 14+13+12+11+10+9+8+7+6+5+4+3+2+1 So always adding to the previous value, by one less. I have never written a sorting algorithm before, and was curious how I might go about setting this up in a much more efficient way than a mile long of if then statements. My original idea was to store values for the floors in an array, and pull from that, using the index to move up or down and subtract or add to the variables. The most elegant solution would be a recursive function that handled this for any selected floor, 1-100, and ran the math, with an output that shows how many drops were needed in order to find that floor. Maximum is always 14, but some can be done in less.

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  • Friends, templates, overloading <<

    - by Crystal
    I'm trying to use friend functions to overload << and templates to get familiar with templates. I do not know what these compile errors are: Point.cpp:11: error: shadows template parm 'class T' Point.cpp:12: error: declaration of 'const Point<T>& T' for this file #include "Point.h" template <class T> Point<T>::Point() : xCoordinate(0), yCoordinate(0) {} template <class T> Point<T>::Point(T xCoordinate, T yCoordinate) : xCoordinate(xCoordinate), yCoordinate(yCoordinate) {} template <class T> std::ostream &operator<<(std::ostream &out, const Point<T> &T) { std::cout << "(" << T.xCoordinate << ", " << T.yCoordinate << ")"; return out; } My header looks like: #ifndef POINT_H #define POINT_H #include <iostream> template <class T> class Point { public: Point(); Point(T xCoordinate, T yCoordinate); friend std::ostream &operator<<(std::ostream &out, const Point<T> &T); private: T xCoordinate; T yCoordinate; }; #endif My header also gives the warning: Point.h:12: warning: friend declaration 'std::ostream& operator<<(std::ostream&, const Point<T>&)' declares a non-template function Which I was also unsure why. Any thoughts? Thanks.

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  • how close a connection from server side that created by ajax from client side

    - by saeid
    I have this sample php code: <?php function response($a) { @ob_end_clean(); header("Connection: close"); ob_start(); echo $a; $length = ob_get_length(); header("Content-Length: $length"); ob_end_flush(); flush(); } response("test1"); sleep(5); echo "test2"; ?> now I make a connection to server from client by ajax. now I want to server only send "test1" to me and then close the connection. but connection not closed and wait 5 seconds and send me "test1 test2" !! this is response headers from server to me : X-Powered-By: PHP/5.3.27 Connection: close Vary: Accept-Encoding,User-Agent Content-Encoding: gzip Cache-Control: private, no-cache, no-store, ------revalidate, no-transform Transfer-Encoding: chunked Content-Type: text/html in response headers I do not see Content-Length header. is problem for this ?? or if not what I must do now for solving problem ??

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  • C++ Template problem adding two data types

    - by Sara
    I have a template class with an overloaded + operator. This is working fine when I am adding two ints or two doubles. How do I get it to add and int and a double and return the double? template <class T> class TemplateTest { private: T x; public: TemplateTest<T> operator+(const TemplateTest<T>& t1)const { return TemplateTest<T>(x + t1.x); } } in my main function i have void main() { TemplateTest intTt1 = TemplateTest<int>(2); TemplateTest intTt2 = TemplateTest<int>(4); TemplateTest doubleTt1 = TemplateTest<double>(2.1d); TemplateTest doubleTt2 = TemplateTest<double>(2.5d); std::cout << intTt1 + intTt2 << /n; std::cout << doubleTt1 + doubleTt2 << /n; } I want to be able to also do this std::cout << doubleTt1 + intTt2 << /n;

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  • Wrong logic in If Statement?

    - by Charles
    $repeat_times = mysql_real_escape_string($repeat_times); $result = mysql_query("SELECT `code`,`datetime` FROM `fc` ORDER by datetime desc LIMIT 25") or die(mysql_error()); $output .=""; $seconds = time() - strtotime($fetch_array["datetime"]); if($seconds < 60) $interval = "$seconds seconds"; else if($seconds < 3600) $interval = floor($seconds / 60) . " minutes"; else if($seconds < 86400) $interval = floor($seconds / 3600) . " hours"; else $interval = floor($seconds / 86400) . " days"; while ($fetch_array = mysql_fetch_array($result)) { $fetch_array["code"] = htmlentities($fetch_array["code"]); $output .= "<li><a href=\"http://www.***.com/code=" . htmlspecialchars(urlencode($fetch_array["code"])) . "\" target=\"_blank\">" . htmlspecialchars($fetch_array["code"]) . "</a> (" . $interval . ") ago.</li>"; } $output .=""; return $output; Why is this returning janice (14461 days) instead of janice (15 minutes ago) The datetime function table has the DATETIME type in my table so it's returning a full string for the date.

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  • How to convert Vector Layer coordinates into Map Latitude and Longitude in Openlayers.

    - by Jenny
    I'm pretty confused. I have a point: x= -12669114.702301 y= 5561132.6760608 That I got from drawing a square on a vector layer with the DrawFeature controller. The numbers seem...erm...awfull large, but they seem to work, because if I later draw a square with all the same points, it's in the same position, so I figure they have to be right. The problem is when I try to convert this point to latitude and longitude. I'm using: map.getLonLatFromPixel(pointToPixel(points[0])); Where points[0] is a geometry Point, and the pointToPixel function takes any point and turns it into a pixel (since the getLonLatFromPixel needs a pixel). It does this by simply taking the point's x, and making it the pixels x, and so on. The latitude and longitude I get is on the order of: lat: -54402718463.864 lng: -18771380.353223 This is very clearly wrong. I'm left really confused. I try projecting this object, using: .transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject()); But I don't really get it and am pretty sure I did it incorrectly, anyways. My code is here: http://pastie.org/909644 I'm sort of at a loss. The coordinates seem consistent, because I can reuse them to get the same result...but they seem way larger than any of the examples I'm seeing on the openLayers website...

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  • PHP Form multiple buttons

    - by Ken
    I have a form with 2 buttons, that depending on which is selected will either be deleted or edited from the database. Those are each individual pages using SQL statements (questionedit and questiondelete). However, when i press a button, nothing happens...Any Ideas Here is my javascript <script type="text/javascript"> function SelectedButton(button) { if(button == 'edit') { document.testedit_questionform.action ="testedit_questionedit.php"; } else if(button == 'delete') { document.testedit_questionform.action ="testedit_questiondelete.php"; } document.forms[].testedit_questionform.submit(); } </script> Here is my form (being echoed from a loop) <form name=\"testedit_questionform\" action=\"SelectedButton\" method=\"POST\"> <span class=\"grid_11 prefix_1\" id=\"\" > Question:<input type=\"text\" name=\"QuestionText\" style=\"width:588px; margin-left:10px;\" value=\"$row[0]\"/> <input type=\"button\" value=\"Edit\" name=\"Operation\"onclick=\"submitForm(\'edit\')\" /> <input type=\"button\" value=\"Delete\" name=\"Operation\"onclick=\"submitForm(\'delete\')\" /> <input type=\"hidden\" name=\"QId\" value=\"$row[3]\" /><br />"); </form>

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  • Dimension Reduction in Categorical Data with missing values

    - by user227290
    I have a regression model in which the dependent variable is continuous but ninety percent of the independent variables are categorical(both ordered and unordered) and around thirty percent of the records have missing values(to make matters worse they are missing randomly without any pattern, that is, more that forty five percent of the data hava at least one missing value). There is no a priori theory to choose the specification of the model so one of the key tasks is dimension reduction before running the regression. While I am aware of several methods for dimension reduction for continuous variables I am not aware of a similar statical literature for categorical data (except, perhaps, as a part of correspondence analysis which is basically a variation of principal component analysis on frequency table). Let me also add that the dataset is of moderate size 500000 observations with 200 variables. I have two questions. Is there a good statistical reference out there for dimension reduction for categorical data along with robust imputation (I think the first issue is imputation and then dimension reduction)? This is linked to implementation of above problem. I have used R extensively earlier and tend to use transcan and impute function heavily for continuous variables and use a variation of tree method to impute categorical values. I have a working knowledge of Python so if something is nice out there for this purpose then I will use it. Any implementation pointers in python or R will be of great help. Thank you.

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  • How to test a C++ library usability in configure.in?

    - by jbatista
    Hi, I'm working on a C++ project and I'm looking for a way to test the existence and usability of IBM Informix's library with the Autotools - namely, editing a configure.in. I don't have experience with Autotools, so basically I'm picking up from the project's configure.in et al. scripts and copying&changing where I feel needs to be changed. IOW, I've been adapting from the existing text in configure.in. So far I've been using successfully the AC_ CHECK_ LIB in configure.in to test whether a certain library both exists and is usable. But this only seems to work with libraries with functions, not e.g. classes. Namely, this fails when testing Informix's libifc++.so: AC_CHECK_LIB(ifc++, ITString, INFORMIX_LIB="-L$INFORMIX_LIB_LOCATION/c++ -lifc++ -L$INFORMIX_LIB_LOCATION -L$INFORMIX_LIB_LOCATION/dmi -L$INFORMIX_LIB_LOCATION/esql -lifdmi -lifsql -lifasf -lifgen -lifos -lifgls -lifglx $INFORMIX_LIB_LOCATION/esql/checkapi.o -lm -ldl -lcrypt -lnsl", echo "* WARNING: libifc++.so not found!" INFORMIX_INC="" INFORMIX_LIB="" ) I've also tried using other combinations, like ITString::ITString, etc. I haven't found a "pure" function in Informix's API (i.e., one that isn't contexted in a C++ class). So I'm hoping that either there's a way to use AC_CHECK_LIB in this context, or there's another autoconf/configure.in "command" for this specific use. Thanks in advance for your feedback.

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  • why my customized marker not showing up in openstreet maps

    - by troy
    I have following java script used for showing the customized marker. But for some reasons its showing up the default marker.. function init() { map = new OpenLayers.Map("basicMap"); var mapnik = new OpenLayers.Layer.OSM(); var fromProjection = new OpenLayers.Projection("EPSG:4326"); var toProjection = new OpenLayers.Projection("EPSG:900913"); var position = new OpenLayers.LonLat(-6.242981,53.331201).transform( fromProjection, toProjection); var zoom = 12; map.addLayer(mapnik); var markers = new OpenLayers.Layer.Markers( "Markers" ); map.addLayer(markers); var size = new OpenLayers.Size(16,28); var offset = new OpenLayers.Pixel(-(size.w*0), -(size.h*1)); var icon = new OpenLayers.Icon('http://m.osmtools.de/images/pin_red.png',size,offset); markers.addMarker(new OpenLayers.Marker(position),icon); map.setCenter(position, zoom ); } And here is my html: <body onload="init();"> <div id="basicMap"></div> </body> I dont understand what wrong with my code .... Please help me.. THank You

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  • How to insert <li> element on <ul> using pure javascript

    - by Damiii
    I am having an issue with javascript and i don't know how to solve it ... Actually my code is working good with jsfiddle, but when i try to insert on my HTML page ,it simply doesnt work anymore ... What i want to, is to add the < li on < ul each time i tried to hit the button named "Add" ! HTML code: .... <td width="50%" valign="top"> <b> SUPER: </b> <ul id="ul"> </ul> </td> .... <input type="submit" value="Add" onclick="add()"/> .... JavaScript code: <script type="text/javascript"> function add(){ var ul = document.getElementById("ul"); var li = document.createElement("li"); li.innerHTML = "LoL"; ul.appendChild(li); } </script> The result with that code : it doesn't add anything on my HTML page when i try to hit the button... Thankfully,

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  • Best way to carry & modify a variable through various instances and functions?

    - by bobsoap
    I'm looking for the "best practice" way to achieve a message / notification system. I'm using an OOP-based approach for the script and would like to do something along the lines of this: if(!$something) $messages->add('Something doesn\'t exist!'); The add() method in the messages class looks somewhat like this: class messages { public function add($new) { $messages = $THIS_IS_WHAT_IM_LOOKING_FOR; //array $messages[] = $new; $THIS_IS_WHAT_IM_LOOKING_FOR = $messages; } } In the end, there is a method in which reads out $messages and returns every message as nicely formatted HTML. So the questions is - what type of variable should I be using for $THIS_IS_WHAT_IM_LOOKING_FOR? I don't want to make this use the database. Querying the db every time just for some messages that occur at runtime and disappear after 5 seconds just seems like overkill. Using global constants for this is apparently worst practice, since constants are not meant to be variables that change over time. I don't even know if it would work. I don't want to always pass in and return the existing $messages array through the method every time I want to add a new message. I even tried using a session var for this, but that is obviously not suited for this purpose at all (it will always be 1 pageload too late). Any suggestions? Thanks!

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  • "Forced constness" in std::map<std::vector<int>,double> > ?

    - by Peter Jansson
    Consider this program: #include <map> #include <vector> typedef std::vector<int> IntVector; typedef std::map<IntVector,double> Map; void foo(Map& m,const IntVector& v) { Map::iterator i = m.find(v); i->first.push_back(10); }; int main() { Map m; IntVector v(10,10); foo(m,v); return 0; } Using g++ 4.4.0, I get his compilation error: test.cpp: In function 'void foo(Map&, const IntVector&)': test.cpp:8: error: passing 'const std::vector<int, std::allocator<int> >' as 'this' argument of 'void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = int, _Alloc = std::allocator<int>]' discards qualifiers I would expect this error if I was using Map::const_iterator inside foo but not using a non-const iterator. What am I missing, why do I get this error?

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  • Obtaining command line arguments in a QT application

    - by morpheous
    The following snippet is from a little app I wrote using the QT framework. The idea is that the app can be run in batch mode (i.e. called by a script) or can be run interactively. It is important therefore, that I am able to parse command line arguments in order to know which mode in which to run etc. [Edit] I am debugging using QTCreator 1.3.1 on Ubuntu Karmic. The arguments are passed in the normal way (i.e. by adding them via the 'Project' settings in the QTCreator IDE). When I run the app, it appears that the arguments are not being passed to the application. The code below, is a snippet of my main() function. int main(int argc, char *argv[]) { //Q_INIT_RESOURCE(application); try { QApplication the_app(argc, argv); //trying to get the arguments into a list QStringList cmdline_args = QCoreApplication::arguments(); // Code continues ... } catch (const MyCustomException &e) { return 1; } return 0; } [Update] I have identified the problem - for some reason, although argc is correct, the elements of argv are empty strings. I put this little code snippet to print out the argv items - and was horrified to see that they were all empty. for (int i=0; i< argc; i++){ std::string s(argv[i]); //required so I can see the damn variable in the debugger std::cout << s << std::endl; } Does anyone know what on earth is going on (or a hammer)?

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  • global variables doesn't change value in Javascript

    - by user1856906
    My project is composed by 2 html pages: 1)index.html, wich contains the login and the registration form. 2)user_logged.html, wich contains all the features of a logged user. Now, what I want to do is a control if the user is really logged, to avoid the case where a user paste a url in the browser and can see the pages of another user. hours as now, if a user paste this url in the browser: www.user_loggato.html?user=x#profile is as if logged in as user x and this is not nice. My html pages both use js files that contains scripts. I decided to create a global variable called logged inizialized to false and change the variable to true when the login is succesfull. The problem is that the variable, remains false. here is the code: var logged=false; (write in the file a.js) while in the file b.js I have: function login() { //if succesfull logged=true; window.location.href = "user_loggato.html?user="+ JSON.parse(str).username + #profilo"; Now with some alerts I found that my variable logged is always false. Why? if I have not explained well or if there is not some information in order to respond to my question let me know.

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  • iterators to range of elements in a vector whose attributes have specific value

    - by user1801173
    I have a vector of objects and I want to return the range of elements whose attribute have a specific value. This is the structure: class A { public: std::vector<B*> vec_; pair<vector<B*>::iterator, vector<B*>::iterator> getElements(unsigned int attr_val); unsigned int name() { return name_; } private: unsigned int name_; }; class B { public: unsigned int attr() { return attr_; } A* source() { return source_; } B* dest() { return dest_; } private: A* source_; B* dest_; unsigned int attr_; }; The vector vec_; is already sorted by attr_ and dest_-name() (in that order). Now I want to return all elements, whose attr_ is equal to attr_val. What is the appropriate stl algorithm (or is there even a vector member function?) to implement getElements(unsigned int attr_val) ? Thanks for help.

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  • contentscript, dynamic created iframe, postmessage

    - by thefoyer
    I'm attempting to inject an iframe from a content script. From the content script, post a message to the iframe, without much success. This is the closest I have got. No errors/warnings in the console but it doesn't work (alert test). contentscript: var iframe = document.createElement("iframe"); iframe.setAttribute("src", "https://www.com/iframe.php"); iframe.id = "iframe01"; document.getElementsByTagName("body")[0].appendChild(iframe); //then I inject this "web_accessible_resources" script var script = document.createElement("script"); script.type = "text/javascript"; script.src = chrome.extension.getURL("postMessage.js"); document.getElementsByTagName("head")[0].appendChild(script); postMessage.js window.postMessage({msg: "test"}, "*"); I've also tried top.postMessage({msg: "test"}, "*"); And var iframe = document.getElementById('iframe01'); iframe.contentWindow.postMessage({msg: "test"}, "*"); EDIT: I tried to make sure the iframe was loaded before postMessage, even if I put an alert there, it would alert telling me the iframe was loaded. var iframe = document.getElementById('iframe01'); if (ifrm_prsto.contentWindow.document) //do postMessage EDIT2: I did get it to work by moving the iframe from the contentscript to the inject.js script. Wasn't totally ideal but I do have it working now, I guess. iframe.php window.addEventListener("message", function(e) {alert("test");}); I am however able to do the reverse, talk to the parent script from the iframe.

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  • Binary Search Tree can't delete the root

    - by Ali Zahr
    Everything is working fine in this function, but the problem is that I can't delete the root, I couldn't figure out what's the bug here.I've traced the "else part" it works fine until the return, it returns the old value I don't know why. Plz Help! node *removeNode(node *Root, int key) { node *tmp = new node; if(key > Root->value) Root->right = removeNode(Root->right,key); else if(key < Root->value) Root->left = removeNode(Root->left, key); else if(Root->left != NULL && Root->right != NULL) { node *minNode = findNode(Root->right); Root->value = minNode->value; Root->right = removeNode(Root->right,Root->value); } else { tmp = Root; if(Root->left == NULL) Root = Root->right; else if(Root->right == NULL) Root = Root->left; delete tmp; } return Root; }

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  • How can I make hundreds of simultaneously running processes communicate with a database through one

    - by Olfan
    Long speech short: How can I make hundreds of simultaneously running processes communicate with a database through one or few permanent sessions? The whole story: I once built a number crunching engine that handles vast amounts of large data files by forking off one child after another giving each a small number of files to work on. File locking, progress monitoring and result propagation happen in an Oracle database which all (sub-)processes access at various times using an application-specific module which encapsulates DBI. This worked well at first, but now with higher volumes of input data, the number of database sessions (one per child, and they can be very short-lived) constantly being opened and closed is becoming an issue. I now want to centralise database access so that there are only one or few fixed database sessions which handle all database access for all the (sub-)processes. The presence of the database abstraction module should make the changes easy because the function calls in the worker instances can stay the same. My problem is that I cannot think of a suitable way to enhance said module in order to establish communication between all the processes and the database connector(s). I thought of message queueing, but couldn't come up with a way of connecting a large herd of requestors with one or few database connectors in a way so that bidirectional communication is possible (for collecting the query result). An asynchronous approach could help here in that all requests are written to the same queue and the database connector servicing the request will "call back" to submit the result. But my mind fails me in generating an image clear enough so that I can paint into code. Threading instead of forking might have given me an easier start, but this would now require massive changes to the code base that I'm not prepared to do to a live system. The more I think of it, the more the base idea looks like a pre-forked web server to me only that it doesn't serve web pages but database queries. Any ideas on what to dig into, and where? Sample (pseudo) code to inspire me, links to possibly related articles, ready solutions on CPAN maybe?

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  • What wrapper class in C++ should I use for automated resource management?

    - by Vilx-
    I'm a C++ amateur. I'm writing some Win32 API code and there are handles and weirdly compositely allocated objects aplenty. So I was wondering - is there some wrapper class that would make resource management easier? For example, when I want to load some data I open a file with CreateFile() and get a HANDLE. When I'm done with it, I should call CloseHandle() on it. But for any reasonably complex loading function there will be dozens of possible exit points, not to mention exceptions. So it would be great if I could wrap the handle in some kind of wrapper class which would automatically call CloseHandle() once execution left the scope. Even better - it could do some reference counting so I can pass it around in and out of other functions, and it would release the resource only when the last reference left scope. The concept is simple - but is there something like that in the standard library? I'm using Visual Studio 2008, by the way, and I don't want to attach a 3rd party framework like Boost or something.

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  • Proper Memory Management for Objective-C Method

    - by Justin
    Hi, I'm programming an iPhone app and I had a question about memory management in one of my methods. I'm still a little new to managing memory manually, so I'm sorry if this question seems elementary. Below is a method designed to allow a number pad to place buttons in a label based on their tag, this way I don't need to make a method for each button. The method works fine, I'm just wondering if I'm responsible for releasing any of the variables I make in the function. The application crashes if I try to release any of the variables, so I'm a little confused about my responsibility regarding memory. Here's the method: FYI the variable firstValue is my label, it's the only variable not declared in the method. -(IBAction)inputNumbersFromButtons:(id)sender { UIButton *placeHolderButton = [[UIButton alloc] init]; placeHolderButton = sender; NSString *placeHolderString = [[NSString alloc] init]; placeHolderString = [placeHolderString stringByAppendingString:firstValue.text]; NSString *addThisNumber = [[NSString alloc] init]; int i = placeHolderButton.tag; addThisNumber = [NSString stringWithFormat:@"%i", i]; NSString *newLabelText = [[NSString alloc] init]; newLabelText = [placeHolderString stringByAppendingString:addThisNumber]; [firstValue setText:newLabelText]; //[placeHolderButton release]; //[placeHolderString release]; //[addThisNumber release]; //[newLabelText release]; } The application works fine with those last four lines commented out, but it seems to me like I should be releasing these variables here. If I'm wrong about that I'd welcome a quick explanation about when it's necessary to release variables declared in functions and when it's not. Thanks.

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  • SWIG_NewPointerObj and values always being nil

    - by Tom J Nowell
    I'm using SWIG to wrap C++ objects for use in lua, and Im trying to pass data to a method in my lua script, but it always comes out as 'nil' void CTestAI::UnitCreated(IUnit* unit){ lua_getglobal(L, "ai"); lua_getfield(L, -1, "UnitCreated"); swig_module_info *module = SWIG_GetModule( L ); swig_type_info *type = SWIG_TypeQueryModule( module, module, "IUnit *" ); SWIG_NewPointerObj(L,unit,type,0); lua_epcall(L, 1, 0); } Here is the lua code: function AI:UnitCreated(unit) if(unit == nil) then game:SendToConsole("I CAN HAS nil ?") else game:SendToConsole("I CAN HAS UNITS!!!?") end end unit is always nil. I have checked and in the C++ code, the unit pointer is never invalid/null I've also tried: void CTestAI::UnitCreated(IUnit* unit){ lua_getglobal(L, "ai"); lua_getfield(L, -1, "UnitCreated"); SWIG_NewPointerObj(L,unit,SWIGTYPE_p_IUnit,0); lua_epcall(L, 1, 0); } with identical results. Why is this failing? How do I fix it?

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