Re: Caching powers of 2 -- performance consideration - C# Discussion Boards

Re: BitVector performance question

Lutosław15-Jan-10 0:33

Lutosław

15-Jan-10 0:33

Covean wrote:
I just found it funny to not be limited and then limit the get function to int.

Right, I should think forward -- maybe some time we will measure memory in peta- or exa-bytes Laugh | :laugh:

Covean wrote:
return (ulong)1 << (i & 0x000000000000003F);

Nice, thanks... (no, not nice in a south park meaning[^]).

Greetings - Jacek

Re: BitVector performance question

Covean15-Jan-10 0:54

Covean

15-Jan-10 0:54

Cool video, thanks for that. Big Grin | :-D

Greetings
Covean

Re: BitVector performance question

Lutosław15-Jan-10 0:04

Lutosław

15-Jan-10 0:04

Covean wrote:
mov cl, dl
movzx rax, bit

This is a real pain in C# - we have to do div and mod seperately and therefore do the same operation twice, since cpu returns both values from div command.

Greetings - Jacek

Re: BitVector performance question

Lutosław15-Jan-10 0:09

Lutosław

15-Jan-10 0:09

Another mark: << operator can be used only for ints or smaller types. For uint/long/ulong it produces compile-time error Dead | X|

Greetings - Jacek

Re: BitVector performance question

Luc Pattyn15-Jan-10 1:47

Luc Pattyn

15-Jan-10 1:47

Jacek Gajek wrote:
<< operator can be used only for ints or smaller

not correct; you can do long << int which is what you need; simply do the AND instead of the modulo, cast to int, then shift.

optimum = no table, no method, just a few in-line statements.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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Re: Caching powers of 2 -- performance consideration

harold aptroot15-Jan-10 4:38

harold aptroot

15-Jan-10 4:38

Jacek Gajek wrote:

My question: Is there any sens in caching masks? that is: {0x0, 0x1, 0x2,... ,0x10, 0x20,....0x100000...}. It would take 0,5 kB.

Only on old CPU's that don't have a single cycle shift by cl

Also, I would really ditch the % and / and use & and >> instead. The optimizer of the JIT compiler does optimize divisions and modulo's by constants, but for signed integers (even when it's trivial to prove that they can not be negative at that point) it wants to perfectly match real modulo en real division (which is not needed since it's not going to be negative anyway)

like: return (table[bit >> 6] & (1ul << bit)) != 0

edit: removed the redundant & 63

Re: Caching powers of 2 -- performance consideration

Lutosław15-Jan-10 11:24

Lutosław

15-Jan-10 11:24

I liked the previous version more Wink | ;)

harold aptroot wrote:
edit: removed the redundant & 63

Why redundant? What if bit=213? I should look at 21th bit of 3rd integer. That is, table[2] & (1ul << 21);

Greetings - Jacek

Re: Caching powers of 2 -- performance consideration

harold aptroot15-Jan-10 11:51

harold aptroot

15-Jan-10 11:51

Bitwise shifts in C# do an implicit shiftamount & (BITSIZE - 1)
Actually x86's do that already by themselves, provided that you used the right operand size (which is always the case for 64bit shifts, but the JIT compiler emits the and instruction anyway)

Generate Color Book File Format (.acb file) for Photoshop using .NET or Other Language

shaktisinh14-Jan-10 19:13

shaktisinh

14-Jan-10 19:13

Dear Developers..
I need to generate a (.acb) file,which ll be used in photoshop.
like other .acb files by photoshop.
I think i have to user dll which give methods to convert file in acb format..
Please give me some sugggestion,hints..!
Thanking you

how to inflate GDI+ Regoins

VCsamir14-Jan-10 19:02

VCsamir

14-Jan-10 19:02

hi friends!!

i just wanted to know is there a way to inflate a region in GDI+, i am creating a region
on runtime using mouse_up event, then i get the region ; now i want to inflate it how can a
acheieve it? i have tried matrixtransformation + scale, is there some other way??

Thanks in Advance

Samir

Any one having code to compare two xml files....?

koolprasad200314-Jan-10 18:48

koolprasad2003

14-Jan-10 18:48

hi all

i want to compare two xml files. does any one having code for this.

any hint ????

thanks in advance
koolprasad2003 Smile | :)

Rating always..... WELCOME

Be a good listener...Because Opprtunity knoughts softly...N-Joy

Re: Any one having code to compare two xml files....?

VCsamir14-Jan-10 18:56

VCsamir

14-Jan-10 18:56

hi,

Are both the files having same structure i.e common tags ,
in this case if you use a class serialization method to read this XML file it can be very handy! You can create the class object of each file and actually come to know which tag is having diffent data.. hope this helps u.. Smile | :)

Best of luck
Samir

Re: Any one having code to compare two xml files....?

koolprasad200314-Jan-10 20:39

koolprasad2003

14-Jan-10 20:39

Thanks for reply sameer,

both my xml files have same structure.

have u any example of class serialization to compare xml file... ??

thanks in advance
koolprasad2003 Smile | :)

Rating always..... WELCOME

Be a good listener...Because Opprtunity knoughts softly...N-Joy

Re: Any one having code to compare two xml files....?

VCsamir14-Jan-10 21:17

VCsamir

14-Jan-10 21:17

hi prasad,

Here a link how you use Xml serialisation in C# http://msdn.microsoft.com/en-us/library/ms950721.aspx

1)your need to build your own class as same stucture as that of the Xml
2) then populate the data in class using XmlReader and input both the files http://msdn.microsoft.com/en-us/library/system.xml.xmltextreader.aspx
3)create instances of class created with two files
4)maybe override the = operater to generate the report of what all data on which tag differ

Hope i am clear!!! Wink | ;)

Best Of Luck Buddy!! Laugh | :laugh:

Samir

Re: Any one having code to compare two xml files....?

J4amieC14-Jan-10 21:31

J4amieC

14-Jan-10 21:31

Let me get this straight.

for 2 xml files which have the same structure you would deserialize your xml into classes and override the whole map's equals functioality and then compare your 2 maps to try to determine if there are any differences.

instead of, say, just comparing the xml to each other using string comparison?

Re: Any one having code to compare two xml files....?

Ashfield14-Jan-10 21:36

Ashfield

14-Jan-10 21:36

J4amieC wrote:
instead of, say, just comparing the xml to each other using string comparison?

Come on, thats far too easy. Where's the opportunity to create abstract classes, interfaces, several layers of inheritance, sub-classes and all the rest of the bloat so it looks like we are earning our crust Smile | :)

Bob
Ashfield Consultants Ltd
Proud to be a Code Project MVP

Re: Any one having code to compare two xml files....?

April Fans14-Jan-10 22:16

April Fans

14-Jan-10 22:16

hi, follow the two links below.

http://forums.devx.com/showthread.php?t=168067
http://www.daniweb.com/forums/thread46345.html#

best regards.

April

Comm100 - Leading Live Chat Software Provider

modified 27-May-14 8:55am.

Newbie struggling with ArgumentException

x3mjeff14-Jan-10 16:55

x3mjeff

14-Jan-10 16:55

Hi,

As the subject states I'm a complete newbie in programming.
I've coded a little program that uses picture boxes to display images of dices.
After filling the picture boxes with an image a PictureBox[pictureBoxNumber].Image.Dispose() is executed.
All the loops I'm using work fine, but if I press the "Alt" or "Alt Gr" key on the keyboard after the button_Click event has run an ArgumentException gets thrown.
The stack trace doesn't make me any wiser though. I've copied it to be able to post it so here it is:

bij System.Drawing.Image.get_Width()
bij System.Drawing.Image.get_Size()
bij System.Windows.Forms.PictureBox.ImageRectangleFromSizeMode(PictureBoxSizeMode mode)
bij System.Windows.Forms.PictureBox.OnPaint(PaintEventArgs pe)
bij System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
bij System.Windows.Forms.Control.WmPaint(Message& m)
bij System.Windows.Forms.Control.WndProc(Message& m)
bij System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
bij System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
bij System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
bij System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
bij System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
bij System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
bij System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
bij System.Windows.Forms.Application.Run(Form mainForm)
bij prjDices.Program.Main() in E:\Mijn documenten\Visual Studio 2008\Projects\solTeerlingen\prjTeerlingen\Program.cs:regel 18
bij System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
bij System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
bij Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
bij System.Threading.ThreadHelper.ThreadStart_Context(Object state)
bij System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
bij System.Threading.ThreadHelper.ThreadStart()

I've been trying to figure out what happens for quite a while now but to no avail.
I'm really completely stuck on this.
If someone could help me understand what causes the exception I'd be very thankful.
I'm not asking for a solution just help to figure out what in heaven's name is going on.

Thanks in advance,

Jeff

Re: Newbie struggling with ArgumentException

Super Lloyd14-Jan-10 17:01

Super Lloyd

14-Jan-10 17:01

I'm curious as to why you Dispose() of the images?
they are in use in the picture box, so disposing them will lead to problems!
maybe that's even the cause (for some twisted reason) of your mysterious problem.
but do dispose of the images, ONCE you got rid of them!

A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station....
_________________________________________________________
My programs never have bugs, they just develop random features.

Re: Newbie struggling with ArgumentException

x3mjeff14-Jan-10 18:15

x3mjeff

14-Jan-10 18:15

Hi Super Lloyd,

Thanks for responding.
About the reason to dispose of the images.
In an application I wrote earlier a picture box control was also used.
When starting the application I also started task manager and observed what happened.
The picture boxes really eat away memory if the images are not disposed of.

Greetz and thanks,

Jeff

Re: Newbie struggling with ArgumentException

Luc Pattyn14-Jan-10 17:29

Luc Pattyn

14-Jan-10 17:29

you can't successfully call Dispose() on an Image inside a PictureBox.

this would be the proper way to switch a PictureBox from image1 to image2:

Image newImage=...;                      // get a new image (maybe from disk)
Image oldImage=pb.Image;
pb.Image=newImage;                       // first replace the old image by the new one
if (oldImage!=null) oldImage.Dispose();  // assuming we never need that old image again in this app

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

Happy New Year to all.
We hope 2010 soon brings us automatic PRE tags!
Until then, please insert them manually.

Re: Newbie struggling with ArgumentException

x3mjeff14-Jan-10 18:32

x3mjeff

14-Jan-10 18:32

Hi Luc,

Thanks for replying.
You made me think about what was going on and yes sir problem solved.
Seeing that I disposed of the images after every loop it's quite obvious that in the next run no images were available.
The solution was actually fairly easy.
Before I dispose of the image I use a boolean expression to determine whether or not an image is present.
Like this:

if (PictureBox[pictureBoxNumber].Image != null) 
{
    PictureBox[pictureBoxNumber].Image.Dispose();
}

Greetz and thanks for the insight,

Jeff

Re: Newbie struggling with ArgumentException

Luc Pattyn15-Jan-10 0:43

Luc Pattyn

15-Jan-10 0:43

that is not good enough, you can't dispose of that image as it is still in use by the PictureBox itself,
you really should do it the way I have shown: copy the reference to a local variable, remove the image from the PictureBox, and only then dispose of it.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

Happy New Year to all.
We hope 2010 soon brings us automatic PRE tags!
Until then, please insert them manually.

modified on Friday, January 15, 2010 7:40 AM

regex problem [modified]

uglyeyes14-Jan-10 15:35

uglyeyes

14-Jan-10 15:35

Hi,
my regex works fine in a regextest tool its just only when i try to filter the content via c# it doesnt work. here is my code

string fName = @"data.txt";//path to text file            StreamReader testTxt = new StreamReader(fName);            string allRead = testTxt.ReadToEnd();//Reads the whole text file to the end            testTxt.Close(); //Closes the text file after it is fully read.            string regMatch = @"(?<=\<div class=""middleadimggold""\>).*?(?=\</div\>)"; //string to search for inside of text file. It is case sensitive.            if (Regex.IsMatch(allRead, regMatch))//If the match is found in allRead            {                Console.WriteLine("found\n");            }            else            {                Console.WriteLine("not found\n");            }

part of the content that should match

<div class="middleadimggold">



<a class="asdf" href="http://www.asdf">
asdf</a>
<p>
asdf</p>
<p>asdf</p><p>asdf</p>

<p><span class="blue">asdf</span>
<a class="de" href="http://www.4asdf"><span class="a">(See on map)</span></a></p>

<p><span class="blue">asdf</span></p>



<span class="xx">


asdf
</span>

</div>

please note the spacing in the content, not sure if it matters?

modified on Thursday, January 14, 2010 10:06 PM

Re: regex problem

uglyeyes14-Jan-10 16:37

uglyeyes

14-Jan-10 16:37

ok this fixed the problem

if (Regex.IsMatch(allRead, regMatch, RegexOptions.Singleline)

singleline option that is. thanks for nothing

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