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Re: [C++/CLI]:impor huge file into memory

ffgtrg1616g261217-Jul-07 22:19

ffgtrg1616g2612

17-Jul-07 22:19

Hello everyone,

As I said I have 4 giga of memory and the file is 5 giga.I use windows Vista64.
and VStudio2005.

Does the serialization work in this case?
What to do to load the file piece by piece?
Is it possible de developp my own serializer ? if yes, can you give me an idea please about how to do it?

Here is my function:
Sine my main class I call this import for differents files, and it is ok when they are not huge.

Here is my function:

FileFormat::openImport(CFile &file, const CString& filename, bool is_binary) const {
FileFormat *self = (FileFormat *) this;
self->filename_ = filename;
self->in_import_ = true;
self->current_line_ = 0;

CFileException file_exception;
if (is_binary) {
if (!file.Open(filename, CFile::modeRead | CFile::typeBinary | CFile::shareDenyWrite, &file_exception))
return openError(file_exception, filename, name_);
}
else {
if (!file.Open(filename, CFile::modeRead | CFile::typeText | CFile::shareDenyWrite, &file_exception))
return openError(file_exception, filename, name_);
}
return true;
}

Thanks.
assia

hgfh

Re: [C++/CLI]:impor huge file into memory

Mark Salsbery18-Jul-07 5:43

Mark Salsbery

18-Jul-07 5:43

You may want to look into using a File Mapping[^] so you can access the
entire huge file without loading the entire file into memory at once.

Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

3 Gb Memory Barrier

George L. Jackson17-Jul-07 14:26

George L. Jackson

17-Jul-07 14:26

This link may or may not apply to your situation but it is interesting:

http://www.dansdata.com/askdan00015.htm[^]

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Implementation of CRC12,CRC16

Kiran Pinjala17-Jul-07 2:30

Kiran Pinjala

17-Jul-07 2:30

hai

Can you please holp me reagarding where can i find the implementation of CRC12,CRC16 algorithms in pure c or c++.

KIRAN PINJARLA

Re: Implementation of CRC12,CRC16

led mike17-Jul-07 4:56

led mike

17-Jul-07 4:56

kiran.pinjarla wrote:
where can i find the implementation of CRC12,CRC16 algorithms in pure c or c++.

You mean somewhere other than the internet?

(solved) strange thing_one digit missing when using %d for standard output [modified]

bloodwinner17-Jul-07 2:15

bloodwinner

17-Jul-07 2:15

I am recording to current time, and compare with the old time which stored in a file. but here t4 is always one digit less.

for example, when I check file end.txt and start.txt, t4 is 22284, and t3 is 21975, no problem.
but when I calculate and output differ, it shows 2228-21975=-19747. t4 is wrong! what is the problem here?

<br />
	int differ=0;<br />
//	int old_time=0;<br />
	int t3=0;<br />
	int t4=0;<br />
	time_t t1,t2;<br />
	FILE * pFile;                <br />
<br />
         	(void) time(&t2);             // record the current time<br />
		t4=(int)t2;<br />
		pFile = fopen ("/root/pclinq/end.txt","r+");<br />
		fprintf (pFile, "%d",t4);         //save the current time to the file<br />
		fclose (pFile);<br />
		<br />
		<br />
		pFile = fopen ("/root/pclinq/start.txt","r+");<br />
		fscanf (pFile, "%d", &t3);             //dig out the old time saved<br />
		fclose (pFile);<br />
		<br />
		differ=t4-t3;<br />
	<br />
	<br />
		printf("differ is %d-%d=%d\n",t4,t3,differ);

(solved)it turns out the last digit was a remaining one, for example,2228 is the real number recorded this time

-- modified at 8:51 Tuesday 17th July, 2007

Re: (solved) strange thing_one digit missing when using %d for standard output

Luc Pattyn17-Jul-07 3:09

Luc Pattyn

17-Jul-07 3:09

bloodwinner wrote:
(solved)it turns out the last digit was a remaining one, for example,2228 is the real number recorded this time

and I guess the more appropriate open mode for writing a file is "w+" ...

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

To know the character strike

mikobi16-Jul-07 22:28

mikobi

16-Jul-07 22:28

Dear Sir,
I am using Visual C++ NET 2005.

How can I know the character(if it's 1,A... etc) that I strike when I am in the textbox field in the Keydown event ?

Re: To know the character strike

Luc Pattyn16-Jul-07 23:23

Luc Pattyn

16-Jul-07 23:23

KeyEventArgs.KeyCode and KeyEventArgs.KeyChar

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

To know the character strike

mikobi16-Jul-07 22:24

mikobi

16-Jul-07 22:24

Dear Sir,
I am using Visual C++ NET 2005.

Re: To know the character strike

Paul Conrad21-Jul-07 18:52

Paul Conrad

21-Jul-07 18:52

mikobi wrote:
I am using Visual C++ NET 2005.

Cool, do you have a question?

"Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

out parameters

a.mulay16-Jul-07 20:37

a.mulay

16-Jul-07 20:37

How to specify out parameters in CLI/C++ like we do in C#? Confused | :confused:

Re: out parameters

G Haranadh16-Jul-07 21:03

G Haranadh

16-Jul-07 21:03

I expect there is no specifically out parameters and in parameters in c++. But for out parameters we should use the reference variable or pointer variable. Like we need to use call by ref concept. Smile | :)

Nice talking to you. Blush | :O

If you judge people, you have no time to love them. -- Mother Teresa

Re: out parameters

George L. Jackson17-Jul-07 12:01

George L. Jackson

17-Jul-07 12:01

To create an out-only parameter, you need to use the Out Attribute and a tracking reference:

using namespace System;
using namespace System::Runtime::InteropServices;
 
public ref class Foo
{
public:
	void Func([Out] String^% value)
	{
		value = "Hello";
	}
};

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Re: out parameters

a.mulay17-Jul-07 17:33

a.mulay

17-Jul-07 17:33

Thanks George!
Smile | :)

Re: out parameters

G Haranadh26-Jul-07 6:46

G Haranadh

26-Jul-07 6:46

Oh. Really Thanks.

Nice talking to you. Blush | :O

If you judge people, you have no time to love them. -- Mother Teresa

Static member variable in class?

G Haranadh16-Jul-07 19:59

G Haranadh

16-Jul-07 19:59

Is the static member variable in class will same for all objects of that class?

Nice talking to you. Blush | :O

If you judge people, you have no time to love them. -- Mother Teresa

Re: Static member variable in class?

Shoaib Hussain17-Jul-07 3:19

Shoaib Hussain

17-Jul-07 3:19

yes static member variables are same for all objects of the class. As the scope of static member variable is class level not of object level. Each object of the class can access and share static member of class.

Static member is accessed via class name and not by object name, like

//static member accessment
className.staticmember = someValue

//object level variable.
objName.objMember

-shoaib-

problem in thread ????????????

abbd16-Jul-07 9:28

abbd

16-Jul-07 9:28

hello,
I have declared a classe, when i creat instance of this classe, it work but when I call a thread it does not work

Thread ^trd;

ThreadStart ^myThreadDelegate = gcnew ThreadStart(this, &BHIDS00::Form1::rep);
trd = gcnew Thread(myThreadDelegate);
trd->IsBackground = true;
trd->Start();

avec rep() { .....................} est une méthode que je veux appelé

or in this methode there are listView->items->add(".."); with thread it doesn't display in listview, and I do rep();

how i do work my methode using thread ???

Merci beaucoup

Re: problem in thread ????????????

led mike16-Jul-07 10:50

led mike

16-Jul-07 10:50

http://blogs.msdn.com/csharpfaq/archive/2004/03/17/91685.aspx[^]

Re: problem in thread ????????????

Mark Salsbery16-Jul-07 12:39

Mark Salsbery

16-Jul-07 12:39

Cool!

I have't used forms yet, but I filed that away for future reference.

Thanks!
Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

L”” or to “” Strings

earlgraham16-Jul-07 9:22

earlgraham

16-Jul-07 9:22

When you see System::String used with “xxx” in some text or example you almost always see the ‘L’ macro in from of the text (L”xxx”). However if I do not use the ‘L’, It seems to have no affect to my String values. Am I missing something?

String ^MyText = "Blah";
//or
String ^MyOtherText = L"Blah";

Same right?

Programmer
Glenn Earl Graham
Austin, TX

Re: L"" or "" Strings [modified]

Mark Salsbery16-Jul-07 9:43

Mark Salsbery

16-Jul-07 9:43

I don't agree with my own reply Smile | :)

I think the compiler now automatically uses the appropriate type when it knows the context.

String ^MyText = "Blah";

The literal "Blah" ends up in the assembly metadata as a CString^, just as using the 'S'
prefix did in VS2003.

hmm - maybe I need to look in the MSIL to see if there's a difference Smile | :)

Mark

-- modified at 15:55 Monday 16th July, 2007

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

Re: L"" or "" Strings

iddqd51516-Jul-07 10:55

iddqd515

16-Jul-07 10:55

Its the same MSIL whether you use L or not.

Re: L"" or "" Strings

Mark Salsbery16-Jul-07 12:21

Mark Salsbery

16-Jul-07 12:21

Cool! Thanks for saving me the time Wink | ;)