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• Structure's with strings and input

  - by Beginnernato

  so i have the following structure and function that add's things to the function - struct scoreentry_node { struct scoreentry_node *next; int score; char* name; } ; typedef struct scoreentry_node *score_entry; score_entry add(int in, char* n, score_entry en) { score_entry r = malloc(sizeof(struct scoreentry_node)); r->score = in; r->name = n; r->next = en; return r; } i have input that take it in the following main file: int score; char name[]; int main(void) { score_entry readin = NULL; while(1) { scanf("%s%d", name, &score); readin = add(score, name, readin); // blah blah I dont know why but when input a name it gets added to readin, but when i input another name all the name's in readin have this new name for example: input: bob 10 readin = 10 bob NULL jill 20 readin = 20 jill 10 jill NULL I dont know why bob disappear's... any reason why it does that ?

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• Detect a USB drive being inserted - Windows Service

  - by Tom Bell

  I am trying to detect a USB disk drive being inserted within a Windows Service, I have done this as a normal Windows application. The problem is the following code doesn't work for volumes. Registering the device notification: DEV_BROADCAST_DEVICEINTERFACE notificationFilter; HDEVNOTIFY hDeviceNotify = NULL; ::ZeroMemory(&notificationFilter, sizeof(notificationFilter)); notificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE); notificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE; notificationFilter.dbcc_classguid = ::GUID_DEVINTERFACE_VOLUME; hDeviceNotify = ::RegisterDeviceNotification(g_serviceStatusHandle, &notificationFilter, DEVICE_NOTIFY_SERVICE_HANDLE); The code from the ServiceControlHandlerEx function: case SERVICE_CONTROL_DEVICEEVENT: PDEV_BROADCAST_HDR pBroadcastHdr = (PDEV_BROADCAST_HDR)lpEventData; switch (dwEventType) { case DBT_DEVICEARRIVAL: ::MessageBox(NULL, "A Device has been plugged in.", "Pounce", MB_OK | MB_ICONINFORMATION); switch (pBroadcastHdr->dbch_devicetype) { case DBT_DEVTYP_DEVICEINTERFACE: PDEV_BROADCAST_DEVICEINTERFACE pDevInt = (PDEV_BROADCAST_DEVICEINTERFACE)pBroadcastHdr; if (::IsEqualGUID(pDevInt->dbcc_classguid, GUID_DEVINTERFACE_VOLUME)) { PDEV_BROADCAST_VOLUME pVol = (PDEV_BROADCAST_VOLUME)pDevInt; char szMsg[80]; char cDriveLetter = ::GetDriveLetter(pVol->dbcv_unitmask); ::wsprintfA(szMsg, "USB disk drive with the drive letter '%c:' has been inserted.", cDriveLetter); ::MessageBoxA(NULL, szMsg, "Pounce", MB_OK | MB_ICONINFORMATION); } } return NO_ERROR; } In a Windows application I am able to get the DBT_DEVTYP_VOLUME in dbch_devicetype, however this isn't present in a Windows Service implementation. Has anyone seen or heard of a solution to this problem, without the obvious, rewrite as a Windows application?

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• Unusual heap size limitations in VS2003 C++

  - by Shane MacLaughlin

  I have a C++ app that uses large arrays of data, and have noticed while testing that it is running out of memory, while there is still plenty of memory available. I have reduced the code to a sample test case as follows; void MemTest() { size_t Size = 500*1024*1024; // 512mb if (Size > _HEAP_MAXREQ) TRACE("Invalid Size"); void * mem = malloc(Size); if (mem == NULL) TRACE("allocation failed"); } If I create a new MFC project, include this function, and run it from InitInstance, it works fine in debug mode (memory allocated as expected), yet fails in release mode (malloc returns NULL). Single stepping through release into the C run times, my function gets inlined I get the following // malloc.c void * __cdecl _malloc_base (size_t size) { void *res = _nh_malloc_base(size, _newmode); RTCCALLBACK(_RTC_Allocate_hook, (res, size, 0)); return res; } Calling _nh_malloc_base void * __cdecl _nh_malloc_base (size_t size, int nhFlag) { void * pvReturn; // validate size if (size > _HEAP_MAXREQ) return NULL; ' ' And (size _HEAP_MAXREQ) returns true and hence my memory doesn't get allocated. Putting a watch on size comes back with the exptected 512MB, which suggests the program is linking into a different run-time library with a much smaller _HEAP_MAXREQ. Grepping the VC++ folders for _HEAP_MAXREQ shows the expected 0xFFFFFFE0, so I can't figure out what is happening here. Anyone know of any CRT changes or versions that would cause this problem, or am I missing something way more obvious?

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• Android: Resolution issue while saving image into gallery

  - by Luca D'Amico

  I've managed to programmatically take a photo from the camera, then display it on an imageview, and then after pressing a button, saving it on the Gallery. It works, but the problem is that the saved photo are low resolution.. WHY?! I took the photo with this code: Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST); Then I save the photo on a var using : protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAMERA_PIC_REQUEST) { thumbnail = (Bitmap) data.getExtras().get("data"); } } and then after displaying it on an imageview, I save it on the gallery with this function: public void SavePicToGallery(Bitmap picToSave, File savePath){ String JPEG_FILE_PREFIX= "PIC"; String JPEG_FILE_SUFFIX= ".JPG"; String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); String imageFileName = JPEG_FILE_PREFIX + timeStamp + "_"; File filePath = null; try { filePath = File.createTempFile(imageFileName, JPEG_FILE_SUFFIX, savePath); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } FileOutputStream out = null; try { out = new FileOutputStream(filePath); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } picToSave.compress(CompressFormat.JPEG, 100, out); try { out.flush(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { out.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } //Add the pic to Android Gallery String mCurrentPhotoPath = filePath.getAbsolutePath(); MediaScannerConnection.scanFile(this, new String[] { mCurrentPhotoPath }, null, new MediaScannerConnection.OnScanCompletedListener() { public void onScanCompleted(String path, Uri uri) { } }); } I really can't figure out why it lose so much quality while saved.. Any help please ? Thanks..

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• sorting a gridview in class

  - by user175084

  ok i have a project which has many gridview in its pages... now i am sorting the fridveiw using the sorting function like this: protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) { DataTable dt = Session["TaskTable2"] as DataTable; if (dt != null) { //Sort the data. dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression); GridView1.DataSource = Session["TaskTable2"]; GridView1.DataBind(); } } private string GetSortDirection(string column) { // By default, set the sort direction to ascending. string sortDirection2 = "ASC"; // Retrieve the last column that was sorted. string sortExpression2 = ViewState["SortExpression2"] as string; if (sortExpression2 != null) { // Check if the same column is being sorted. // Otherwise, the default value can be returned. if (sortExpression2 == column) { string lastDirection = ViewState["SortDirection2"] as string; if ((lastDirection != null) && (lastDirection == "ASC")) { sortDirection2 = "DESC"; } } } // Save new values in ViewState. ViewState["SortDirection2"] = sortDirection2; ViewState["SortExpression2"] = column; return sortDirection2; } but this code is being repeated in many pages so i tried to put this function in a C# class and try to call it but i get errors.... for starters i get the viewstate error saying :| "viewstate does not exist in the current context" so how do i go about doing this ....?? thanks

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• Using an SHA1 with Micrsoft CAPI

  - by Erik Jõgi

  Hello, I have an SHA1 hash and I need to sign it. The CryptSignHash() method requires a HCRYPTHASH handle for signing. I create it and as I have the actual hash value already then set it: CryptCreateHash(cryptoProvider, CALG_SHA1, 0, 0, &hash); CryptSetHashParam(hash, HP_HASHVAL, hashBytes, 0); The hashBytes is an array of 20 bytes. However the problem is that the signature produced from this HCRYPTHASH handle is incorrect. I traced the problem down to the fact that CAPI actually doesn't use all 20 bytes from my hashBytes array. For some reason it thinks that SHA1 is only 4 bytes. To verify this I wrote this small program: HCRYPTPROV cryptoProvider; CryptAcquireContext(&cryptoProvider, NULL, NULL, PROV_RSA_FULL, 0); HCRYPTHASH hash; HCRYPTKEY keyForHash; CryptCreateHash(cryptoProvider, CALG_SHA1, keyForHash, 0, &hash); DWORD hashLength; CryptGetHashParam(hash, HP_HASHSIZE, NULL, &hashLength, 0); printf("hashLength: %d\n", hashLength); And this prints out hashLength: 4 ! Can anyone explain what I am doing wrong or why Microsoft CAPI thinks that SHA1 is 4 bytes (32 bits) instead of 20 bytes (160 bits). Thank you.

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• Getting "prompt aborted by user" javascript exception

  - by Bhagwat

  I am getting "Components.Exception("prompt aborted by user", Cr.NS_ERROR_NOT_AVAILABLE)" exception when I am using "windows.location.href" in javasacript. My Code is: function checkCookie(){ var value = null; var cookieName='UserDetailsCookie'; value=ReadCookie(cookieName); if(value != null){ var url='<%=request.getContextPath()%>/jsp/admin.jsp'; window.location.href = url; } document.loginForm.userName.focus(); } function ReadCookie(name) { name += '='; var parts = document.cookie.split(/;\s*/); for (var i = 0; i < parts.length; i++) { var part = parts[i]; if (part.indexOf(name) == 0) return part.substring(name.length); } return null; } and I am calling this method on onLoad event of body <body onLoad="javascript:checkCookie();"> In anyone knows why this exception throws please?

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• iPhone and iPad : Doing a "select * from something" query in a SQLite database

  - by Abramodj

  Hi folks, i'm trying to use the SQLite data base in my iPad app, and here's my function to make a query: - (void)executeQuery:(char*)query { NSString *file = [self getWritableDBPath]; NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL success = [fileManager fileExistsAtPath:file]; // If its not a local copy set it to the bundle copy if(!success) { //file = [[NSBundle mainBundle] pathForResource:DATABASE_TITLE ofType:@"db"]; [self createEditableCopyOfDatabaseIfNeeded]; } dataArray = NULL; dataArray = [NSMutableArray array]; sqlite3 *database = NULL; if (sqlite3_open([file UTF8String], &database) == SQLITE_OK) { sqlite3_exec(database, query, loadTimesCallback, dataArray, NULL); } sqlite3_close(database); [self logResults]; } if I call [self executeQuery:"select name from table1"]; everything is working fine. But if i call [self executeQuery:"select * from cars"]; the app crashes telling me that the NSMutableArray dataArray is not the right kind of variable where to set the query results. So, how can i do a "select * form table1" query, and store the results? Thanks! EDIT: Here's my loadTimesCallback method: static int loadTimesCallback(void *context, int count, char **values, char **columns) { NSMutableArray *times = (NSMutableArray *)context; for (int i=0; i < count; i++) { const char *nameCString = values[i]; [times addObject:[NSString stringWithUTF8String:nameCString]]; } return SQLITE_OK; }

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• Mysql query in drupal database - groupwise maximum with duplicate data

  - by nselikoff

  I'm working on a mysql query in a Drupal database that pulls together users and two different cck content types. I know people ask for help with groupwise maximum queries all the time... I've done my best but I need help. This is what I have so far: # the artists SELECT users.uid, users.name AS username, n1.title AS artist_name FROM users LEFT JOIN users_roles ur ON users.uid=ur.uid INNER JOIN role r ON ur.rid=r.rid AND r.name='artist' LEFT JOIN node n1 ON n1.uid = users.uid AND n1.type = 'submission' WHERE users.status = 1 ORDER BY users.name; This gives me data that looks like: uid username artist_name 1 foo Joe the Plumber 2 bar Jane Doe 3 baz The Tooth Fairy Also, I've got this query: # artwork SELECT n.nid, n.uid, a.field_order_value FROM node n LEFT JOIN content_type_artwork a ON n.nid = a.nid WHERE n.type = 'artwork' ORDER BY n.uid, a.field_order_value; Which gives me data like this: nid uid field_order_value 1 1 1 2 1 3 3 1 2 4 2 NULL 5 3 1 6 3 1 Additional relevant info: nid is the primary key for an Artwork every Artist has one or more Artworks valid data for field_order_value is NULL, 1, 2, 3, or 4 field_order_value is not necessarily unique per Artist - an Artist could have 4 Artworks all with field_order_value = 1. What I want is the row with the minimum field_order_value from my second query joined with the artist information from the first query. In cases where the field_order_value is not valuable information (either because the Artist has used duplicate values among their Artworks or left that field NULL), I would like the row with the minimum nid from the second query.

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• MySQL nested CASE error I need help with?

  - by AK

  What I am trying to do here is: IF the records in table todo as identified in $done have a value in the column recurinterval then THEN reset date_scheduled column ELSE just set status_id column to 6 for those records. This is the error I get from mysql_error() ... You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CASE recurinterval != 0 AND recurinterval IS NOT NULL THEN SET date_sche' at line 2 How can I make this statement work? UPDATE todo CASE recurinterval != 0 AND recurinterval IS NOT NULL THEN SET date_scheduled = CASE recurunit WHEN 'DAY' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval DAY) WHEN 'WEEK' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval WEEK) WHEN 'MONTH' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval MONTH) WHEN 'YEAR' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval YEAR) END WHERE todo_id IN ($done) ELSE SET status_id = 6 WHERE todo_id IN ($done) END The following mySQL statement worked just fine before I revised like above. UPDATE todo SET date_scheduled = CASE recurunit WHEN 'DAY' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval DAY) WHEN 'WEEK' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval WEEK) WHEN 'MONTH' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval MONTH) WHEN 'YEAR' THEN DATE_ADD(date_scheduled, INTERVAL recurinterval YEAR) END WHERE todo_id IN ($done) AND recurinterval != 0 AND recurinterval IS NOT NULL

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• How to handle array element between int and Integer

  - by masato-san

  First, it is long post so if you need clarification please let me know. I'm new to Java and having difficulty deciding whether I should use int[] or Integer[]. I wrote a function that find odd_number from int[] array. public int[] find_odd(int[] arr) { int[] result = new int[arr.length]; for(int i=0; i<arr.length; i++) { if(arr[i] % 2 != 0) { //System.out.println(arr[i]); result[i] = arr[i]; } } return result; } Then, when I pass the int[] array consisting of some integer like below: int[] myArray = {-1, 0, 1, 2, 3}; int[] result = find_odd(myArray); The array "result" contains: 0, -1, 0, 1, 0, 3 Because in Java you have to define the size of array first, and empty int[] array element is 0 not null. So when I want to test the find_odd() function and expect the array to have odd numbers (which it does) only, it throws the error because the array also includes 0s representing "empty cell" as shown above. My test code: public void testFindOddPassValidIntArray() { int[] arr = {-2, -1, 0, 1, 3}; int[] result = findOddObj.find_odd(arr); //check if return array only contain odd number for(int i=0; i<result.length; i++) { if(result[i] != null) { assert is_odd(result[i]) : result[i]; } } } So, my question is should I use int[] array and add check for 0 element in my test like: if(result[i] != 0) { assert is_odd(result[i] : result[i] } But in this case, if find_odd() function is broken and returning 0 by miscalculation, I can't catch it because my test code would only assume that 0 is empty cell. OR should I use Integer[] array whose default is null? How do people deal with this kind of situation?

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• Force orientation change in testcase with fragments

  - by user1202032

  I have an Android test project in which I wish to programatically change the orientation. My test: public class MainActivityLandscapeTest extends ActivityInstrumentationTestCase2<MainActivity> { public MainActivityLandscapeTest() { super(MainActivity.class); } private MainActivity mActivity; private Fragment mDetailFragment; private Fragment mListFragment; private Solo mSolo; @Override protected void setUp() throws Exception { super.setUp(); mSolo = new Solo(getInstrumentation(), getActivity()); mSolo.setActivityOrientation(Solo.LANDSCAPE); mActivity = getActivity(); mListFragment = (Fragment) mActivity.getSupportFragmentManager() .findFragmentById(R.id.listFragment); mDetailFragment = (Fragment) mActivity.getSupportFragmentManager() .findFragmentById(R.id.detailFragment); } public void testPreConditions() { assertTrue(mActivity != null); assertTrue(mSolo != null); assertTrue(mListFragment != null); assertTrue(getActivity().getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE); } /** * Only show detailFragment in landscape mode */ public void testOrientation() { assertTrue(mListFragment.isVisible()); assertTrue(mDetailFragment.isVisible()); } } The layouts for the activity is in seperate folders, layout-port and layout-land layout-port fragment_main.xml layout-land fragment_main.xml In landscape mode, the layout contains 2 fragments (Detail and list) while in portrait it contains 1(List only). If the device/emulator is already in landscape mode before testing begins, this test passes. If in portrait, it fails with a NullPointerException on mListFragment and mDetailFragment. Adding a delay (waitForIdleSync() and/or waitForActivity()) did NOT seem to solve my problem. How do i force the orientation to landscape in my test, while still being able to find the fragments using findFragmentById()?

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• Where can we use "This" in Recursion methode...

  - by T_Geek

  Hi . I have a methode in a static class which try to convert bi*nar*y tre to list I'd like to make a recusion but I couldn't I've implemented some opertation in my class like add,delet,find.it's too easy to implement its . Here is the code class ARB { private: struct BT { int data; BT *l; BT *r; }; struct BT *p; public ARB(); ~ARB(); void del(int n); void add(int n); }; void ARB::del(int num) { //The code ,don't care about it }; main() { // BTR T; T.add(3); T.add(5); }; Here is what should we do to transfert the code from Benary tree tolist LLC ARB::changeit() { LLC x; while(this!=NULL) { x.add(this->data); // if(this.l==NULL) { x.print(); //To print the elemnts of List return(x); } else { x=changeit(this.l); } if(this.r!=NULL) { x.~LLC(); x=changeit(this.r); return(x); } } }

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• Streaming audio not working in Android

  - by user320293

  Hi, I'm sure that this question has been asked before but I've been unable to find a solid answer. I'm trying to load a streaming audio from a server. Its a audio/aac file http://3363.live.streamtheworld.com:80/CHUMFMAACCMP3 The code that I'm using is private void playAudio(String str) { try { final String path = str; if (path == null || path.length() == 0) { Toast.makeText(RadioPlayer.this, "File URL/path is empty", Toast.LENGTH_LONG).show(); } else { // If the path has not changed, just start the media player MediaPlayer mp = new MediaPlayer(); mp.setAudioStreamType(AudioManager.STREAM_MUSIC); try{ mp.setDataSource(getDataSource(path)); mp.prepareAsync(); mp.start(); }catch(IOException e){ Log.i("ONCREATE IOEXCEPTION", e.getMessage()); }catch(Exception e){ Log.i("ONCREATE EXCEPTION", e.getMessage()); } } } catch (Exception e) { Log.e("RPLAYER EXCEPTION", "error: " + e.getMessage(), e); } } private String getDataSource(String path) throws IOException { if (!URLUtil.isNetworkUrl(path)) { return path; } else { URL url = new URL(path); URLConnection cn = url.openConnection(); cn.connect(); InputStream stream = cn.getInputStream(); if (stream == null) throw new RuntimeException("stream is null"); File temp = File.createTempFile("mediaplayertmp", ".dat"); temp.deleteOnExit(); String tempPath = temp.getAbsolutePath(); FileOutputStream out = new FileOutputStream(temp); byte buf[] = new byte[128]; do { int numread = stream.read(buf); if (numread <= 0) break; out.write(buf, 0, numread); } while (true); try { stream.close(); } catch (IOException ex) { Log.e("RPLAYER IOEXCEPTION", "error: " + ex.getMessage(), ex); } return tempPath; } } Is this the correct implementation? I'm not sure where I'm going wrong. Can someone please please help me on this.

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• Calling into a saved java object via JNI from a different thread

  - by Drake Amara

  I have a java object which calls into a C++ shared object via JNI. In C++, I am saving a reference to the JNIEnv and jObject. JavaVM * jvm; JNIEnv * myEnv; jobject myobj; JNIEXPORT void JNICALL Java_org_api_init (JNIEnv *env, jobject jObj) { myEnv = env; myobj = jObj; } I also have a GLSurface renderer and it eventually calls the C++ shared object mentioned above on a different thread, the GLThread. I am then trying to call back into my original Java object using the jobject I saved initially, but I think because I am on the GLThread, I get the following error. W/dalvikvm(16101): JNI WARNING: 0x41ded218 is not a valid JNI reference I/dalvikvm(16101): "GLThread 981" prio=5 tid=15 RUNNABLE I/dalvikvm(16101): | group="main" sCount=0 dsCount=0 obj=0x41d6e220 self=0x5cb11078 I/dalvikvm(16101): | sysTid=16133 nice=0 sched=0/0 cgrp=apps handle=1555429136 I/dalvikvm(16101): | schedstat=( 0 0 0 ) utm=42 stm=32 core=1 The code calling back into Java : void setData() { jvm->AttachCurrentThread(&myEnv, 0); jclass javaClass = myEnv->FindClass("com/myapp/myClass"); if(javaClass == NULL){ LOGD("ERROR - cant find class"); } jmethodID method = myEnv->GetMethodID(javaClass, "updateDataModel", "()V"); if(method == NULL){ LOGD("ERROR - cant access method"); } // this works, but its a new java object //jobject myobj2 = myEnv->NewObject(javaClass, method); //this is where the crash occurs myEnv->CallVoidMethod(myobj, method, NULL); } If instead I create a new jObject using env-NewObject, I can succuessfully call back into Java, but it is a new object and I dont want that. I need to get back to my original Java Object. Is it a matter of switching threads before I call back into Java? If so, how do I do so ?

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• C++ templated factory constructor/de-serialization

  - by KRao

  Hi, I was looking at the boost serialization library, and the intrusive way to provide support for serialization is to define a member function with signature (simplifying): class ToBeSerialized { public: //Define this to support serialization //Notice not virtual function! template<class Archive> void serialize(Archive & ar) {.....} }; Moreover, one way to support serilization of derived class trough base pointers is to use a macro of the type: //No mention to the base class(es) from which Derived_class inherits BOOST_CLASS_EXPORT_GUID(Derived_class, "derived_class") where Derived_class is some class which is inheriting from a base class, say Base_class. Thanks to this macro, it is possible to serialize classes of type Derived_class through pointers to Base_class correctly. The question is: I am used in C++ to write abstract factories implemented through a map from std::string to (pointer to) functions which return objects of the desired type (and eveything is fine thanks to covariant types). Hover I fail to see how I could use the above non-virtual serialize template member function to properly de-serialize (i.e. construct) an object without knowing its type (but assuming that the type information has been stored by the serializer, say in a string). What I would like to do (keeping the same nomenclature as above) is something like the following: XmlArchive xmlArchive; //A type or archive xmlArchive.open("C:/ser.txt"); //Contains type information for the serialized class Base_class* basePtr = Factory<Base_class>::create("derived_class",xmlArchive); with the function on the righ-hand side creating an object on the heap of type Derived_class (via default constructor, this is the part I know how to solve) and calling the serialize function of xmlArchive (here I am stuck!), i.e. do something like: Base_class* Factory<Base_class>::create("derived_class",xmlArchive) { Base_class* basePtr = new Base_class; //OK, doable, usual map string to pointer to function static_cast<Derived_class*>( basePtr )->serialize( xmlArchive ); //De-serialization, how????? return basePtr; } I am sure this can be done (boost serialize does it but its code is impenetrable! :P), but I fail to figure out how. The key problem is that the serialize function is a template function. So I cannot have a pointer to a generic templated function. As the point in writing the templated serialize function is to make the code generic (i.e. not having to re-write the serialize function for different Archivers), it does not make sense then to have to register all the derived classes for all possible archive types, like: MY_CLASS_REGISTER(Derived_class, XmlArchive); MY_CLASS_REGISTER(Derived_class, TxtArchive); ... In fact in my code I relies on overloading to get the correct behaviour: void serialize( XmlArchive& archive, Derived_class& derived ); void serialize( TxtArchive& archive, Derived_class& derived ); ... The key point to keep in mind is that the archive type is always known, i.e. I am never using runtime polymorphism for the archive class...(again I am using overloading on the archive type). Any suggestion to help me out? Thank you very much in advance! Cheers

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• Any suggestions to improve my PDO connection class?

  - by Scarface

  Hey guys I am pretty new to pdo so I basically just put together a simple connection class using information out of the introductory book I was reading but is this connection efficient? If anyone has any informative suggestions, I would really appreciate it. class PDOConnectionFactory{ public $con = null; // swich database? public $dbType = "mysql"; // connection parameters public $host = "localhost"; public $user = "user"; public $senha = "password"; public $db = "database"; public $persistent = false; // new PDOConnectionFactory( true ) <--- persistent connection // new PDOConnectionFactory() <--- no persistent connection public function PDOConnectionFactory( $persistent=false ){ // it verifies the persistence of the connection if( $persistent != false){ $this->persistent = true; } } public function getConnection(){ try{ $this->con = new PDO($this->dbType.":host=".$this->host.";dbname=".$this->db, $this->user, $this->senha, array( PDO::ATTR_PERSISTENT => $this->persistent ) ); // carried through successfully, it returns connected return $this->con; // in case that an error occurs, it returns the error; }catch ( PDOException $ex ){ echo "We are currently experiencing technical difficulties. We have a bunch of monkies working really hard to fix the problem. Check back soon: ".$ex->getMessage(); } } // close connection public function Close(){ if( $this->con != null ) $this->con = null; } }

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• CURL C API: callback was not called

  - by Pierre

  Hi all, The code below is a test for the CURL C API . The problem is that the callback function write_callback is never called. Why ? /** compilation: g++ source.cpp -lcurl */ #include <assert.h> #include <iostream> #include <cstdlib> #include <cstring> #include <cassert> #include <curl/curl.h> using namespace std; static size_t write_callback(void *ptr, size_t size, size_t nmemb, void *userp) { std::cerr << "CALLBACK WAS CALLED" << endl; exit(-1); return size*nmemb; } static void test_curl() { int any_data=1; CURLM* multi_handle=NULL; CURL* handle_curl = ::curl_easy_init(); assert(handle_curl!=NULL); ::curl_easy_setopt(handle_curl, CURLOPT_URL, "http://en.wikipedia.org/wiki/Main_Page"); ::curl_easy_setopt(handle_curl, CURLOPT_WRITEDATA, &any_data); ::curl_easy_setopt(handle_curl, CURLOPT_VERBOSE, 1); ::curl_easy_setopt(handle_curl, CURLOPT_WRITEFUNCTION, write_callback); ::curl_easy_setopt(handle_curl, CURLOPT_USERAGENT, "libcurl-agent/1.0"); multi_handle = ::curl_multi_init(); assert(multi_handle!=NULL); ::curl_multi_add_handle(multi_handle, handle_curl); int still_running=0; /* lets start the fetch */ while(::curl_multi_perform(multi_handle, &still_running) == CURLM_CALL_MULTI_PERFORM ); std::cerr << "End of curl_multi_perform."<< endl; //cleanup should go here ::exit(EXIT_SUCCESS); } int main(int argc,char** argv) { test_curl(); return 0; } Many thanks Pierre

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• Check if date is allowed weekday in php?

  - by moogeek

  Hello! I'm stuck with a problem how to check if a specific date is within allowed weekdays array in php. For example, function dateIsAllowedWeekday($_date,$_allowed) { if ((isDate($_date)) && (($_allowed!="null") && ($_allowed!=null))){ $allowed_weekdays=json_decode($_allowed); $weekdays=array(); foreach($allowed_weekdays as $wd){ $weekday=date("l",date("w",strtotime($wd))); array_push($weekdays,$weekday); } if(in_array(date("l",strtotime($_date)),$weekdays)){return TRUE;} else {return FALSE;} } else {return FALSE;} } ///////////////////////////// $date="21.05.2010"; $wd="[0,1,2]"; if(dateIsAllowedWeekday($date,$wd)){echo "$date is within $wd weekday values!";} else{echo "$date isn't within $wd weekday values!"} I have input dates formatted as "d.m.Y" and an array returned from database with weekday numbers (formatted as 'Numeric representation of the day of the week') like [0,1,2] - (Sunday,Monday,Tuesday). The returned string from database can be "null", so i check it too. Them, the isDate function checks whether date is a date and it is ok. I want to check if my date, for example 21.05.2010 is an allowed weekday in this array. My function always returns TRUE and somehow weekday is always 'Thursday' and i don't know why... Is there any other ways to check this or what can be my error in the code above? thx

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• Why does my jQuery/YQL call not return anything?

  - by tastyapple

  I'm trying to access YQL with jQuery but am not getting a response: http://jsfiddle.net/tastyapple/grMb3/ Anyone know why? $(function(){ $.extend( { _prepareYQLQuery: function (query, params) { $.each( params, function (key) { var name = "#{" + key + "}"; var value = $.trim(this); if (!value.match(/^[0-9]+$/)) { value = '"' + value + '"'; } query = query.replace(name, value); } ); return query; }, yql: function (query) { var $self = this; var successCallback = null; var errorCallback = null; if (typeof arguments[1] == 'object') { query = $self._prepareYQLQuery(query, arguments[1]); successCallback = arguments[2]; errorCallback = arguments[3]; } else if (typeof arguments[1] == 'function') { successCallback = arguments[1]; errorCallback = arguments[2]; } var doAsynchronously = successCallback != null; var yqlJson = { url: "http://query.yahooapis.com/v1/public/yql", dataType: "jsonp", success: successCallback, async: doAsynchronously, data: { q: query, format: "json", env: 'store://datatables.org/alltableswithkeys', callback: "?" } } if (errorCallback) { yqlJson.error = errorCallback; } $.ajax(yqlJson); return $self.toReturn; } } ); $.yql( "SELECT * FROM github.repo WHERE id='#{username}' AND repo='#{repository}'", { username: "jquery", repository: "jquery" }, function (data) { if (data.results.repository["open-issues"].content > 0) { alert("Hey dude, you should check out your new issues!"); } } ); });

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• jQuery $.ajax calls success handler when reuqest fails because of browser reloading

  - by Martin

  I have the following code: $.ajax({ type: "POST", url: url, data: sendable, dataType: "json", success: function(data) { if(customprocessfunc) customprocessfunc(data); }, error: function(XMLHttpRequest, textStatus, errorThrown){ // error handler here } }); I have a timer which makes AJAX requests often. If I do not receive anything in 'data', I show an error message to the user - it means, something wnet bad on the server. The problem is when user reloads the page while the AJAX call is in progress. I can see in the firebug that the AJAX call fails (URL is colored red and no HTTP status is displayed) so I expect that jQuery will stop the reuqest or at least go to the error handler. But it goes to the success handler and passes null in the 'data' variable. As a result, when user reloads the page, sometimes he can see my big red message about unknown error (because data is null). Is there any way to make jQuery abort the request on complete reloading all at least not to call my success function? I have no way to know in the success handler why the data is null - did it came empty from the server or the call was aborted because of reload.

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• Getting a gestureoverlayview

  - by Codejoy

  I have been using some nice tutorials on drawing graphics on my android. I wanted to also add in the cool gesture demo found here: http://developer.android.com/resources/articles/gestures.html That takes these lines of code: GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gestures); gestures.addOnGesturePerformedListener(this); This is fine and dandy yet I realize in my demo i'm trying to build using code from "Playing with Graphics in Android". The demos make sense, everything makes sense but I found out by using: setContentView(new Panel(this)); as is required by the Playing With Graphics tutorials, then the findViewById seems to no longer be valid and returns null. At first I was about to post a stupider question as to why this is happening, a quick test of playing with the setContentView made me realize the cause of findViewById returning null, I just do not know how to remedy this issue. Whats the key I am missing here? I realize that the new Panel is doinking some reference up but I am not sure how to make the connection here. The: R.id.gestures is defined right int he main.xml as: (just like the tutorial) <android.gesture.GestureOverlayView android:id="@+id/gestures" android:layout_width="fill_parent" android:layout_height="0dip" android:layout_weight="1.0" /> So I did confirm the setContentView(new Panel(this)) is causing the issue. So I know the issue is that I have to figure out how to add the android.gesture.GestureOverlayView to the panel class somehow, I am just not sure how to go about this. After fighting with this I generally know what I need to do just now how to do it. I think I need either the equivalent of creating a panel in that main.xml OR figuring out how to build whats in main.xml for the gestures in code. I am close because I did this: GestureOverlayView gestures = new GestureOverlayView(this); which gets me a non null gestures now, unfortunately since I am not telling it to fill Parent anywhere I don't think its really showing up, so I am trying hard to figure out layout pa rams. Am I even on the right track?

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• How to make command-line options mandatory with GLib?

  - by ahe

  I use GLib to parse some command-line options. The problem is that I want to make two of those options mandatory so that the program terminates with the help screen if the user omits them. My code looks like this: static gint line = -1; static gint column = -1; static GOptionEntry options[] = { {"line", 'l', 0, G_OPTION_ARG_INT, &line, "The line", "L"}, {"column", 'c', 0, G_OPTION_ARG_INT, &column, "The column", "C"}, {NULL} }; ... int main(int argc, char** argv) { GError *error = NULL; GOptionContext *context; context = g_option_context_new ("- test"); g_option_context_add_main_entries (context, options, NULL); if (!g_option_context_parse(context, &argc, &argv, &error)) { usage(error->message, context); } ... return 0; } If I omit one of those parameters or both on the command-line g_option_context_parse() still succeeds and the values in question (line and or column) are still -1. How can I tell GLib to fail parsing if the user doesn't pass both options on the command-line? Maybe I'm just blind but I couldn't find a flag I can put into my GOptionEntry data structure to tell it to make those fields mandatory. Of course I could check if one of those variables is still -1 but then the user could just have passed this value on the command-line and I want to print a separate error message if the values are out of range.

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• Crash using WscRegisterForChanges.

  - by user335126

  I'm trying to use the WscRegisterForChanges with C++ function in Windows 7. Documentation located here: http://msdn.microsoft.com/en-us/library/bb432507(v=VS.85).aspx My problem is that even though the callback properly executes, the code crashes when it gets to the end of the callback's execution. Here's the code in question. It's very simple, so I'm not sure why it's crashing: #include #include #include void SecurityCenterChangeOccurred(void *param) { printf("Change occurred!\n"); } int main() { HRESULT result = S_OK; HANDLE callbackRegistration = NULL; result = WscRegisterForChanges( NULL, &callbackRegistration, (LPTHREAD_START_ROUTINE)SecurityCenterChangeOccurred, NULL); while(1) { Sleep(100); } return 0; } My call stack looks like this when the crash occurs: 00faf6e8() ntdll.dll!_TppWorkerThread@4() + 0x1293 bytes kernel32.dll!@BaseThreadInitThunk@12() + 0x12 bytes ntdll.dll!___RtlUserThreadStart@8() + 0x27 bytes ntdll.dll!__RtlUserThreadStart@8() + 0x1b bytes If I add ExitThread(0); to the end of SecurityCenterChangeOccurred, I get an error and the following trace (So I don't think I should be using ExitThread): Unhandled exception at 0x7799852b (ntdll.dll) in WscRegisterForChangesCrash.exe: 0xC000071C: An invalid thread, handle %p, is specified for this operation. Possibly, a threadpool worker thread was specified. ntdll.dll!_TpCheckTerminateWorker@4() + 0x3ca2f bytes ntdll.dll!_RtlExitUserThread@4() + 0x30 bytes WscRegisterForChangesCrash.exe!SecurityCenterChangeOccurred(void * param=0x00000000) Line 8 + 0xa bytes C++ wscapi.dll!WorkItemWrapper() + 0x19 bytes ntdll.dll!_RtlpTpWorkCallback@8() + 0xdf bytes ntdll.dll!_TppWorkerThread@4() + 0x1293 bytes kernel32.dll!@BaseThreadInitThunk@12() + 0x12 bytes ntdll.dll!___RtlUserThreadStart@8() + 0x27 bytes ntdll.dll!__RtlUserThreadStart@8() + 0x1b bytes Does anyone have any ideas why this might be happening? To trigger the crash run the program and turn the firewall on or off.

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• Code Contracts: Do we have to specify Contract.Requires(...) statements redundantly in delegating me

  - by herzmeister der welten

  I'm intending to use the new .NET 4 Code Contracts feature for future development. This made me wonder if we have to specify equivalent Contract.Requires(...) statements redundantly in a chain of methods. I think a code example is worth a thousand words: public bool CrushGodzilla(string weapon, int velocity) { Contract.Requires(weapon != null); // long code return false; } public bool CrushGodzilla(string weapon) { Contract.Requires(weapon != null); // specify contract requirement here // as well??? return this.CrushGodzilla(weapon, int.MaxValue); } For runtime checking it doesn't matter much, as we will eventually always hit the requirement check, and we will get an error if it fails. However, is it considered bad practice when we don't specify the contract requirement here in the second overload again? Also, there will be the feature of compile time checking, and possibly also design time checking of code contracts. It seems it's not yet available for C# in Visual Studio 2010, but I think there are some languages like Spec# that already do. These engines will probably give us hints when we write code to call such a method and our argument currently can or will be null. So I wonder if these engines will always analyze a call stack until they find a method with a contract that is currently not satisfied? Furthermore, here I learned about the difference between Contract.Requires(...) and Contract.Assume(...). I suppose that difference is also to consider in the context of this question then?

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