storing retrieveing Uint64 data

  • julia Cline storing retrieveing Uint64 data Dec 26 2006, 17:25
    I'm trying to capture a time using suggestions from list users :

    UInt64 startTime = UnsignedWideToUInt64(AbsoluteToNanoseconds(UpTime()));

    I'd like to store the caputred times in an array object and retrieve them later for calculating reaction times to an onscreen display.

    I've tried using:

    UInt64 startTime = UnsignedWideToUInt64(AbsoluteToNanoseconds(UpTime()));
    printf (" \n\nstart time %llu  ", startTime);  //checking value
    pass ++;
    printf ("at pass = %d\n\n", pass);  //tracking iteration through method
    [nextButtonPressed insertObject:  [NSNumber numberWithUnsignedLongLong: startTime] atIndex:pass]; //hopefully putting value into array
    NSLog(@"\nafter storage starttime is %llu\n\n",[[nextButtonPressed objectAtIndex:pass] longLongUnsignedValue]);  //checking value to compare to original

    The log output looks like this:

    start time 73580042471882  at pass = 1

    2006-12-26 08:16:43.544 WordView[5736]
    after storage starttime is 4294967296

    The value that I think I am storing is not the one that I am retrieveing.  Can anyone help me understand what is going on?

    Also,  should I be using NSArrayController.  I discovered it with all its nifty actions, but i can't get it to instantiate and I haven't locate any documentation about it.  If I should use it, where can I find some references that discuse how to use it?

    thanks,

    Julia
  • mmalc crawford Re: storing retrieveing Uint64 data Dec 26 2006, 18:04
    On Dec 26, 2006, at 8:25 AM, julia Cline wrote:

    > Also,  should I be using NSArrayController.  I discovered it with
    > all its nifty actions, but i can't get it to instantiate and I
    > haven't locate any documentation about it.  If I should use it,
    > where can I find some references that discuse how to use it?
    >
    <http://www.google.com/search?rls=en-us&q=NSArrayController>

    mmalc
  • Nir Soffer Re: storing retrieveing Uint64 data Dec 26 2006, 19:37
    On Dec 26, 2006, at 18:25, julia Cline wrote:

    > UInt64 startTime = UnsignedWideToUInt64(AbsoluteToNanoseconds(UpTime
    > ()));
    > printf (" \n\nstart time %llu  ", startTime);  //checking value
    > pass ++;
    > printf ("at pass = %d\n\n", pass);  //tracking iteration through
    > method
    > [nextButtonPressed insertObject:  [NSNumber
    > numberWithUnsignedLongLong: startTime] atIndex:pass]; //hopefully
    > putting value into array

    Hopefully ? :-)

    The way to append values to an array is addObject: and not
    insertObject:. I guess that you can remove the "pass" temporary if
    you use addObject.

    Read file:///Developer/ADC%20Reference%20Library/documentation/Cocoa/
    Conceptual/Collections/index.html

    Are you sure that "nextButtonPressed" is a proper name for a
    collection of timestamps?

    > NSLog(@"\nafter storage starttime is %llu\n\n",[[nextButtonPressed
    > objectAtIndex:pass] longLongUnsignedValue]);  //checking value to
    > compare to original
    >
    > The log output looks like this:
    >
    > start time 73580042471882  at pass = 1
    >
    > 2006-12-26 08:16:43.544 WordView[5736]
    > after storage starttime is 4294967296

    Maybe its difference between printf and NSLog formatting?

    This is an easier and more correct way to check:

        UInt64 nano = UnsignedWideToUInt64(AbsoluteToNanoseconds(UpTime
    ()));

        NSNumber *nanoNumber = [NSNumber numberWithUnsignedLongLong:nano];

        assert(nano == [nanoNumber unsignedLongLongValue]);

    Best Regards,

    Nir Soffer