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• Two "Calendar" entries listed on iPad - can't write to calendar using EventKit

  - by Neal

  My iOS app integrates with the device's calendar. On my iPad when I view the calendar app and tap the Calendars button on the top left to choose which calendars to show I see one entry named "Calendar". In my app when I loop through available calendars per the code below "Calendar" is listed twice. One is CalDAV for the type, the other is Local. I'm unable to create calendar entries in one of them, I believe the "Local" one, not sure why. Why do I see "Calendar" listed twice when I do NOT see it listed twice in the iCal app? public static List<string> Calendars { get { var calendars = new List<string>(); var ekCalendars = EventStore.Calendars; if (ekCalendars != null && ekCalendars.Length > 0) { foreach (EKCalendar cal in ekCalendars) { if (cal.AllowsContentModifications) calendars.Add(cal.Title); } calendars.Sort(); } return calendars; } }

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• Why does this log output show the same answer in each iteration?

  - by Will Hancock

  OK, I was reading an article on optimising JS for Googles V8 engine, when i saw this code example... I nearly skimmed over it, but then I saw this; |=; a[0] |= b; a = new Array(); a[0] = 0; for (var b = 0; b < 10; b++) { console.log(a, b) a[0] |= b; // Much better! 2x faster. } a[0] |= b; So I ran it, in my console, with a console.log in the loop and resulted in 15; [15] 0 [15] 1 [15] 2 [15] 3 [15] 4 [15] 5 [15] 6 [15] 7 [15] 8 [15] 9 WHAT?!?! Where the hell does it get 15 from, on every iteration?!?!?! I've been a web dev for 7 years, and this has stumped me and a fellow colleague. Can somebody talk me through this code? Cheers.

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• How to get an array to check in the in_array function? See description Below...

  - by Parth

  I am fetching the data using mysql_fetch_array like : while($row = mysql_fetch_array($select)) { $tables[] =$row; } Now i need this $tables array as one dimensional array only, so that i can use it in if(in_array($val['table_name'],$tables)) { //Some Code } to check for whether the $val['table_name'] is in the $tables or not.. As for now I am getting $tables array as Array ( [0] => Array ( [TABLE_NAME] => jos_audittrail ) [1] => Array ( [TABLE_NAME] => jos_banner ) [2] => Array ( [TABLE_NAME] => jos_bannerclient ) .. .. .. .. } But I need the $tables is form of.. Array ( [0] => jos_audittrail [TABLE_NAME] => jos_audittrail [1] => jos_banner [TABLE_NAME] => jos_banner [2] => jos_bannerclient [TABLE_NAME] => jos_bannerclient .. .. .. } How can i get the above array after applying "while loop" to "$row"?

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• Cross-platform HTML application options

  - by Charles

  I'd like to develop a stand-alone desktop application targeting Windows (XP through 7) and Mac (Tiger through Snow Leopard), and if possible iPhone and Android. In order to make it all work with as much common code as possible (and because it's the only thing I'm good at), I'd like to handle the main logic with HTML and JS. Using Adobe AIR is a possibility. And I think I can do this with various application wrappers, using .NET for Windows XP, Objective C for iPhone, Java for Android and native "widget" platform support for Mac and Windows Vista & 7 (though I'd like to keep the widget in the foreground, so the Mac dashboard isn't ideal). Does anyone have any suggestions on where to start? The two sticking points are: I'll certainly need some form of persistent storage (cookies perhaps) to keep state between sessions I'll also probably need access to remote data files, so if I use AJAX and the hosting HTML file resides on the device, it will need to be able to do cross-domain requests. I've done this on the iPhone without any problems, but I'd be surprised if this were possible on other platforms. For me, Android and iPhone will be the easiest to handle, and it looks like I can use Adobe AIR to handle the rest. But I wanted to know if there are any other alternatives. Does anyone have any suggesions?

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• Does Function pointer make the program slow?

  - by drigoSkalWalker

  Hi guys. I read about function pointers in C And everyone said that will make my program run slow. Is it true? I made a program to check it. And I got the same results on both cases. (mesure the time.) So, is it bad to use fuction pointer? Thanks in advance. To response for some guys. I said 'run slow' for the time that I have compared on a loop. like this. int end = 1000; int i = 0; while (i < end) { fp = func; fp (); } When you execute this, i got the same time if I execute this. while (i < end) { func (); } So I think that function pointer have no difference of time and it don't make a program run slow as many people said.

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• Why is CoRegisterClassObject creating two extra threads?

  - by Stijn Sanders

  I'm trying to fix a problem that only recently happens on a number of machine's on a VPN. They each run a client application I wrote that exposes a COM automation object. For some strange reason I haven't been able to discover yet, one thread in the application takes up all of the available CPU time, slowing other operation on the machine. In observing the application's strange behaviour, I've noticed it's the third thread started, and if I debug on my machine I notice the first call to CoRegisterClassObject created two extra threads. If the second of these two threads is the one that gets into an infinite loop, I'm not at all shure how to fix this. Where could I check next about what's wrong? Could it have started by one of the recent patches rolled out by Microsoft this last 'patch tuesday'? I had a go with ProcessExplorer to extract a stack trace of the thread: ntoskrnl.exe!ExReleaseResourceLite+0x1a3 ntoskrnl.exe!PsGetContextThread+0x329 WLDAP32.dll!Ordinal325+0x1231 WLDAP32.dll!Ordinal325+0x129e WLDAP32.dll!Ordinal325+0x1178 ntdll.dll!LdrInitializeThunk+0x24 ntdll.dll!LdrShutdownThread+0xe9 kernel32.dll!ExitThread+0x3e kernel32.dll!FreeLibraryAndExitThread+0x1e ole32.dll!StringFromGUID2+0x65d kernel32.dll!GetModuleFileNameA+0x1ba

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• c# Convert LINQ var result to actual type

  - by DrBob

  In c#, Given the following code: public class Person { public int PersonID { get; set; } public int Age { get; set; } public string Name { get; set; } } and List<Person> people = new List<Person>(); for (int i = 0; i != 15; i++) { Person p = new Person(); p.PersonID = i; p.Age = i * 12; p.Name = "Name " + i; people.Add(p); } var sortedPeople = from qPeople in people where qPeople.Age > 0 && qPeople.Age < 25 || qPeople.Age > 100 orderby qPeople.Age descending select qPeople; Can I load the results of sortedPeople back into a List<Person without a loop? Thanks.

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• Passing Extras and screen rotation

  - by Luis A. Florit

  This kind of questions appear periodically. Sorry if this has been covered before, but I'm a newbie and couldn't find the appropriate answer. It deals with the correct implementation of communication between classes and activities. I made a gallery app. It has 3 main activities: the Main one, to search for filenames using a pattern; a Thumb one, that shows all the images that matched the pattern as thumbnails in a gridview, and a Photo activity, that opens a full sized image when you click a thumb in Thumbs. I pass to the Photo activity via an Intent the filenames (an array), and the position (an int) of the clicked thumb in the gridview. This third Photo activity has only one view on it: a TouchImageView, that I adapted for previous/next switching and zooming according to where you shortclick on the image (left, right or middle). Moreover, I added a longclick listener to Photo to show EXIF info. The thing is working, but I am not happy with the implementation... Some things are not right. One of the problems I am experiencing is that, if I click on the right of the image to see the next in the Photo activity, it switches fine (position++), but when rotating the device the original one at position appears. What is happening is that Photo is destroyed when rotating the image, and for some reason it restarts again, without obeying super.onCreate(savedInstanceState), loading again the Extras (the position only changed in Photo, not on the parent activities). I tried with startActivityForResult instead of startActivity, but failed... Of course I can do something contrived to save the position data, but there should be something "conceptual" that I am not understanding about how activities work, and I want to do this right. Can someone please explain me what I am doing wrong, which is the best method to implement what I want, and why? Thanks a lot!!!

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• How should I link two items with MouseMovementListeners?

  - by user1708810

  I'm working on a program that will display two "views" of the same set of items. So I need to have something set up so that when the top down view is changed, the side view is updated (and vice versa). Here's a brief outline of the relevant code so you can get an idea of my structure so far: public class DraggableComponent extends JComponent { //Contains code for MouseMovementListener that makes the item draggable } public class ItemGraphic extends DraggableComponent { //Code to render the graphic } public class Item { private ItemGraphic topGraphic; private ItemGraphic sideGraphic; } I'm able to get each graphic to display fine in my GUI. I can also independently drag each graphic. I'm missing the "linking." Some ideas I've been thinking about: Have one listener for the whole GUI. Loop through each Item and if the cursor is within the bounds of either graphic, move the other graphic. I'm concerned about the efficiency of this method. Multiple "paired" listeners (not quite sure how this would work, but the idea is that each graphic would have a listener for the other paired graphic)

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• Socket select() Handling Abrupt Disconnections

  - by Genesis

  I am currently trying to fix a bug in a proxy server I have written relating to the socket select() call. I am using the Poco C++ libraries (using SocketReactor) and the issue is actually in the Poco code which may be a bug but I have yet to receive any confirmation of this from them. What is happening is whenever a connection abruptly terminates the socket select() call is returning immediately which is what I believe it is meant to do? Anyway, it returns all of the disconnected sockets within the readable set of file descriptors but the problem is that an exception "Socket is not connected" is thrown when Poco tries to fire the onReadable event handler which is where I would be putting the code to deal with this. Given that the exception is silently caught and the onReadable event is never fired, the select() call keeps returning immediately resulting in an infinite loop in the SocketReactor. I was considering modifying the Poco code so that rather than catching the exception silently it fires a new event called onDisconnected or something like that so that a cleanup can be performed. My question is, are there any elegant ways of determining whether a socket has closed abnormally using select() calls? I was thinking of using the exception message to determine when this has occured but this seems dirty to me.

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• How can i create an n-dimensional array in c

  - by shortCircuit

  I was thinking of making a function that would accept the size of array as a parameter and create a n dimensional array. My room-mate took the liberty of making it complex. He said lets write a function that takes n parameters and returns an n-dimensional array using those parameters as the dimensions. Now i realize an one-day and d array is easy to implement with pointers. For 2d array the snippet would be something like (standard way) : int** x; int* temp; x = (int**)malloc(m * sizeof(int*)); temp = (int*)malloc(m*n * sizeof(int)); for (int i = 0; i < m; i++) { x[i] = temp + (i * n); } where the array is of size m*n; But the problem lies how do we find the nested loop parameters for a n-dimensional array? Is there any way to optimize the code?

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• what use does the javascript for each method have (that map can't do)?

  - by JohnMerlino

  Hey all, The only difference I see in map and foreach is that map is returning an array and foreach is not. However, I don't even understand the last line of the foreach method "func.call(scope, this[i], i, this);". For example, isn't "this" and "scope" referring to same object and isn't this[i] and i referring to the current value in the loop? I noticed on another post someone said "Use forEach when you want to do something on the basis of each element of the list. You might be adding things to the page, for example. Essentially, it's great for when you want "side effects". I don't know what is meant by side effects. Array.prototype.map = function(fnc) { var a = new Array(this.length); for (var i = 0; i < this.length; i++) { a[i] = fnc(this[i]); } return a; } Array.prototype.forEach = function(func, scope) { scope = scope || this; for (var i = 0, l = this.length; i < l; i++) func.call(scope, this[i], i, this); } Finally, are there any real uses for these methods in javascript (since we aren't updating a database) other than to manipulate numbers like this: alert([1,2,3,4].map(function(x){ return x + 1})); //this is the only example I ever see of map in javascript. Thanks for any reply.

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• What hash algorithms are parallelizable? Optimizing the hashing of large files utilizing on multi-co

  - by DanO

  I'm interested in optimizing the hashing of some large files (optimizing wall clock time). The I/O has been optimized well enough already and the I/O device (local SSD) is only tapped at about 25% of capacity, while one of the CPU cores is completely maxed-out. I have more cores available, and in the future will likely have even more cores. So far I've only been able to tap into more cores if I happen to need multiple hashes of the same file, say an MD5 AND a SHA256 at the same time. I can use the same I/O stream to feed two or more hash algorithms, and I get the faster algorithms done for free (as far as wall clock time). As I understand most hash algorithms, each new bit changes the entire result, and it is inherently challenging/impossible to do in parallel. Are any of the mainstream hash algorithms parallelizable? Are there any non-mainstream hashes that are parallelizable (and that have at least a sample implementation available)? As future CPUs will trend toward more cores and a leveling off in clock speed, is there any way to improve the performance of file hashing? (other than liquid nitrogen cooled overclocking?) or is it inherently non-parallelizable?

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• File IO with Streams - Best Memory Buffer Size

  - by AJ

  I am writing a small IO library to assist with a larger (hobby) project. A part of this library performs various functions on a file, which is read / written via the FileStream object. On each StreamReader.Read(...) pass, I fire off an event which will be used in the main app to display progress information. The processing that goes on in the loop is vaired, but is not too time consuming (it could just be a simple file copy, for example, or may involve encryption...). My main question is: What is the best memory buffer size to use? Thinking about physical disk layouts, I could pick 2k, which would cover a CD sector size and is a nice multiple of a 512 byte hard disk sector. Higher up the abstraction tree, you could go for a larger buffer which could read an entire FAT cluster at a time. I realise with today's PC's, I could go for a more memory hungry option (a couple of MiB, for example), but then I increase the time between UI updates and the user perceives a less responsive app. As an aside, I'm eventually hoping to provide a similar interface to files hosted on FTP / HTTP servers (over a local network / fastish DSL). What would be the best memory buffer size for those (again, a "best-case" tradeoff between perceived responsiveness vs. performance).

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• Spring MessageSource not being used during validation

  - by Jeremy

  I can't get my messages in messages.properties to be used during Spring validation of my form backing objects. app-config.xml: <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basename" value="messages" /> </bean> WEB-INF/classes/messages.properties: NotEmpty=This field should not be empty. Form Backing Object: ... @NotEmpty @Size(min=6, max=25) private String password; ... When I loop through all errors in the BindingResult and output the ObjectError's toString I get this: Field error in object 'settingsForm' on field 'password': rejected value []; codes [NotEmpty.settingsForm.password,NotEmpty.password,NotEmpty.java.lang.String,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [settingsForm.password,password]; arguments []; default message [password]]; default message [may not be empty] As you can see the default message is "may not be empty" instead of my message "This field should not be empty". I do get my correct message if I inject the messageSource into a controller and output this: messageSource.getMessage("NotEmpty", new Object [] {"password"}, "default empty message", null); So why isn't the validation using my messages.properties? I'm running Spring 3.1.1. Thanks!

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• Does tableViewController behave incorrectly when hosted by a popoverController?

  - by dugla

  I have made countless test examples of a tableViewController hosted by a popoverController and I have come to the following conclusion: It does not appear possible to pre-select a tableView cell. It is possible to do pre-selection when a tableViewController is hosted by a splitviewController. I am using the exact same tableViewController code. Here is the relevant tableViewController view lifecycle method that is misbehaving: static BOOL firstTime = YES; - (void)viewDidAppear:(BOOL)animated { NSLog(@"Root ViewController - view Did Appear"); [super viewDidAppear:animated]; if (firstTime == YES) { firstTime = NO; NSIndexPath *preselectedCell = [NSIndexPath indexPathForRow:5 inSection:0]; [self.tableView selectRowAtIndexPath:preselectedCell animated:NO scrollPosition:UITableViewScrollPositionTop]; detailViewController.detailItem = [NSString stringWithFormat:@"Row %d", preselectedCell.row]; } // if (firstTime == YES) } The above code correctly preselects a tableView cell the first time the tableView is unfurled in the splitViewController case (device in portrait mode). Can someone please, please, explain what I am doing wrong. I am completely stumped. Thanks, Doug

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• Why does Perl's Devel::LeakTrace::Fast point to blank files and evals?

  - by kt

  I am using Devel::LeakTrace::Fast to debug a memory leak in a perl script designed as a daemon which runs an infinite loop with sleeps until interrupted. I am having some trouble both reading the output and finding documentation to help me understand the output. The perldoc doesn't contain much information on the output. Most of it makes sense, such as pointing to globals in DBI. Intermingled with the output, however, are several leaked SV(<LOCATION>) from (eval #) line # Where the numbers are numbers and <LOCATION> is a location in memory. The script itself is not using eval at any point - I have not investigated each used module to see if evals are present. Mostly what I want to know is how to find these evals (if possible). I also find the following entries repeated over and over again leaked SV(<LOCATION>) from line # Where line # is always the same #. Not very helpful in tracking down what file that line is in.

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• Adding a Way To preserve A Comma In A CSV To DataTable Function

  - by Nick LaMarca

  I have a function that converts a .csv file to a datatable. One of the columns I am converting is is a field of names that have a comma in them i.e. "Doe, John" when converting the function treats this as 2 seperate fields because of the comma. I need the datatable to hold this as one field Doe, John in the datatable. Function CSV2DataTable(ByVal filename As String, ByVal sepChar As String) As DataTable Dim reader As System.IO.StreamReader Dim table As New DataTable Dim colAdded As Boolean = False Try ''# open a reader for the input file, and read line by line reader = New System.IO.StreamReader(filename) Do While reader.Peek() >= 0 ''# read a line and split it into tokens, divided by the specified ''# separators Dim tokens As String() = System.Text.RegularExpressions.Regex.Split _ (reader.ReadLine(), sepChar) ''# add the columns if this is the first line If Not colAdded Then For Each token As String In tokens table.Columns.Add(token) Next colAdded = True Else ''# create a new empty row Dim row As DataRow = table.NewRow() ''# fill the new row with the token extracted from the current ''# line For i As Integer = 0 To table.Columns.Count - 1 row(i) = tokens(i) Next ''# add the row to the DataTable table.Rows.Add(row) End If Loop Return table Finally If Not reader Is Nothing Then reader.Close() End Try End Function

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• Pass view to viewmodel with datatemplate

  - by jpsstavares

  I have a ParameterView and ParameterViewModel, and I need the ParameterViewModel to have a reference to the Parameter view (more on that later). In the window I have a list of ParameterViewModels and in the ResourceDictionary I add the DataTemplate: <DataTemplate DataType="{x:Type my:ParameterViewModel}" > <my:ParameterView HorizontalAlignment="Left"/> </DataTemplate> I then bind an ItemsControl.ItemSource to the List of ParameterViewModels The problem is: How can I pass the ParameterView to the ParameterViewModel in this scenario? The reason I need the ParameterView in the ParameterViewModel is the following: I have a TextBox whose Text property is binded to the PropertyModelView.Name property. But I want to display a default string when the Name is empty or Null. I've tried to set the property value to the default string I want when that happens but the TextBox.Text is not set in this scenario. I do something like this: private string _name; public string Name { get { return _name; } set { if (value == null || value.Length == 0) Name = _defaultName; else _name = value; } } I've also tried to specifically set the TextBox.Text binding mode to TwoWay without success. I think this is a defense mechanism to prevent an infinite loop from happening but I don't know for sure. Any help on this front would also be highly appreciated. Thanks, José Tavares

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• Displaying cookies as key=value for all domains?

  - by OverTheRainbow

  Hello, This question pertains to the use of the cookie-capable WebClient derived class presented in the How can I get the WebClient to use Cookies? question. I'd like to use a ListBox to... 1) display each cookie individually as "key=value" (the For Each loop displays all of them as one string), and 2) be able to display all cookies, regardless of the domain from which they came ("www.google.com", here): Imports System.IO Imports System.Net Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim webClient As New CookieAwareWebClient Const URL = "http://www.google.com" Dim response As String response = webClient.DownloadString(URL) RichTextBox1.Text = response 'How to display cookies as key/value in ListBox? 'PREF=ID=5e770c1a9f279d5f:TM=1274032511:LM=1274032511:S=1RDPaKJKpoMT9T54 For Each mycc In webClient.cc.GetCookies(New Uri(URL)) ListBox1.Items.Add(mycc.ToString) Next End Sub End Class Public Class CookieAwareWebClient Inherits WebClient Public cc As New CookieContainer() Private lastPage As String Protected Overrides Function GetWebRequest(ByVal address As System.Uri) As System.Net.WebRequest Dim R = MyBase.GetWebRequest(address) If TypeOf R Is HttpWebRequest Then With DirectCast(R, HttpWebRequest) .CookieContainer = cc If Not lastPage Is Nothing Then .Referer = lastPage End If End With End If lastPage = address.ToString() Return R End Function End Class Thank you.

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• jQuery - Compatibility Problem with Internet Explorer 7 and Opera

  - by Marius

  Hello there, I have this counter which counts + 1 every time somebody shares content from the site. When it happens, the social icon that was clicked will bounce. It works in Firefox,Chrome, IE8, and Opera, however the bouncing animation is wrong in opera. $.fn.countExternal = function(animSpeed, num) { // for each counter this.each(function(){ // select all the digit containers var span = $(this).children(); // count the num of digit containers var len = $(span).length; // get the current count u = $(span).text(); // copy variable and add increment(s) v = num + ''; // foreach digit container... for (i=v.length - 1; i >= 0; i--) { // ...check which digits are not affected by the increment(s) if (v.charAt(i) == u.charAt(i)) { break; } } // slice from the total number of digit containers the digits containers which needs updating. slce = len - (v.length - (i + 1)) var updates = $(span).slice(slce); // loop through each digit container and fade out ... $(updates).fadeTo(animSpeed, 0,function(){ $(updates).each(function(index){ f = i + 1 + index; // ...then pick the right digit and update the digit... $(this).text(v.charAt(f)); // ...before fading back in. Cycle complete. $(this).fadeTo(animSpeed, 1); }); }); }); }; }) (jQuery); Demo (NSFW) is here (look underneath the social sharing icons). Any idea how I can solve the IE, and possibly the Opera compatibility problem? Thank you for your time.

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• Generating an NSDictionary from an SQL statement.

  - by Ed Wist

  I am trying to generate an NSDictonary that can be used to populate a listview with data I retrieved from an SQL statement. when I go to create an array and add them it adds the arrays for ALL my keys and not just for the current key. I've tried a removeAllObjects on the array but for some reason that destroys ALL my data that I already put in the dictionary. //open the database if(sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) { const char *sql = "select alphaID, word from words order by word"; sqlite3_stmt *selectStatement; //prepare the select statement int returnValue = sqlite3_prepare_v2(database, sql, -1, &selectStatement, NULL); if(returnValue == SQLITE_OK) { NSMutableArray *NameArray = [[NSMutableArray alloc] init]; NSString *alphaTemp = [[NSString alloc] init]; //loop all the rows returned by the query. while(sqlite3_step(selectStatement) == SQLITE_ROW) { NSString *currentAlpha = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectStatement, 1)]; NSString *definitionName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectStatement, 2)]; if (alphaTemp == nil){ alphaTemp = currentAlpha; } if ([alphaTemp isEqualToString:(NSString *)currentAlpha]) { [NameArray addObject:definitionName]; } else if (alphaTemp != (NSString *)currentAlpha) { [self.words setObject:NameArray forKey:currentAlpha]; [NameArray removeAllObjects]; [NameArray addObject:definitionName]; } } } The Statement above adds all the "keys" but then removes all the array elements for all keys. if I take out the removeAllKeys it adds ALL the array elements for ALL keys. I don't want this I want it to add the array elements FOR the specific key then move on to the next key. in the end I want a NSDictonary with A (array) Alpha (string) Apple (string) B (array) Beta (string) Ball (string) C (array) Code (string) ...

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• google app engine atomic section???

  - by bokertov

  hi, Say you retrieve a set of records from the datastore (something like: select * from MyClass where reserved='false'). how do i ensure that another user doesn't set the reserved is still false? I've looked in the Transaction documentation and got shocked from google's solution which is to catch the exception and retry in a loop. Any solution that I'm missing - it's hard to believe that there's no way to have an atomic operation in this environment. (btw - i could use 'syncronize' inside the servlet but i think it's not valid as there's no way to ensure that there's only one instance of the servlet object, isn't it? same applies to static variable solution) Any idea on how to solve??? (here's the google solution: http://code.google.com/appengine/docs/java/datastore/transactions.html#Entity_Groups look at: Key k = KeyFactory.createKey("Employee", "k12345"); Employee e = pm.getObjectById(Employee.class, k); e.counter += 1; pm.makePersistent(e); This requires a transaction because the value may be updated by another user after this code fetches the object, but before it saves the modified object. Without a transaction, the user's request will use the value of counter prior to the other user's update, and the save will overwrite the new value. With a transaction, the application is told about the other user's update. If the entity is updated during the transaction, then the transaction fails with an exception. The application can repeat the transaction to use the new data. THANKS!

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• Indexing/Performance strategies for vast amount of the same value

  - by DrColossos

  Base information: This is in context to the indexing process of OpenStreetMap data. To simplify the question: the core information is divided into 3 main types with value "W", "R", "N" (VARCHAR(1)). The table has somewhere around ~75M rows, all columns with "W" make up ~42M rows. Existing indexes are not relevant to this question. Now the question itself: The indexing of the data is done via an procedure. Inside this procedure, there are some loops that do the following: [...] SELECT * FROM table WHERE the_key = "W"; [...] The results get looped again and the above query itself is also in a loop. This takes a lot of time and slows down the process massivly. An indexon the_key is obviously useless since all the values that the index might use are the same ("W"). The script itself is running with a speed that is OK, only the SELECTing takes very long. Do I need to create a "special" kind of index that takes this into account and makes the SELECT quicker? If so, which one? need to tune some of the server parameters (they are already tuned and the result that they deliver seem to be good. If needed, I can post them)? have to live with the speed and simply get more hardware to gain more power (Tim Taylor grunt grunt)? Any alternatives to the above points (except rewriting it or not using it)?

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• Timeout Exceptions

  - by Raihan Jamal

  This is my below code, I am confuse why this thing is happening. In this code getLocationByIpTimeout is a method in which I am passing two things- one is the ip address and second is the timeout. So I will get the timeout exception if the response is not getting back in under 5 ms. So when I ran this below code, I am getting few timeout exceptions but the most important thing that I am confuse is if I am getting timeout exceptions (time taken to get the response is greater than 5 ms) then why the program is entering in that if loop in which I am having difference 5. What can be the possible reason for this? It is because of catch block?? Any suggestions will be appreciated. long runs =10000; long difference = 0; while(runs > 0) { String ipAddress = generateIPAddress(); long start_time = System.nanoTime(); try { resp = PersonalizationGeoLocationServiceClientHelper.getLocationByIpTimeout(ipAddress, 5); } catch (TimeoutException e) { System.out.println("Timeout Exception"); } long end_time = System.nanoTime(); if(resp == null || (resp.getLocation() == null)) { difference = 0; } else if(resp.getLocation() != null) { difference = (end_time - start_time)/1000000; } if(difference> 5) { System.out.println("Debug"); } }

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