|
If I know I'll be dealing with millions of objects, and assigning them to vectors, is there an algorithm I can use to determine what size I should initially set the vector to, in order to avoid (as much as possible) the vector from constantly growing (which it is constantly doing as more and more objects are "pushed" into it)?
For example, if the vector is going to grow from 200K to 400K, and then from 400K to 800K, and from 800K to 1.6 Million (and so forth), I'd like to set the vector to 2 million right from the very start, just to avoid the system from having to use up time constantly allocating more space, then copying from the old over to the new (etc.), and simply cut to the chase.
It's an algorithm I looking for that would let me enter the variables and have it give me a good estimate of what size I sould make the vector at the beginning.
Thanks for any insight.
William
Fortes in fide et opere!
|
|
|
|
|
The solution depends on the type of object. What object is it?
Kuphryn
|
|
|
|
|
There's not much here to work with... exactly what are the input variables?
- Mike
|
|
|
|
|
std::vector<double> v_dbl; // create an empty vector
v.reserve(100); // reserve memory for 100 elements
or
std::vector<t> v(100); // creates a vector and initializes it with 100 values
// but calls the default contructor of type T 100 times.
|
|
|
|
|
Thanks for your reply.
I just found out about the "reserve()" member function of vector about a week ago, and it seemed to be the answer nearest to the concern I presented.
I'm constantly challenged by the STL, and likewise finding solutions (within itself) to the various problems for which I'm using it in the first place.
Thanks.
William
Fortes in fide et opere!
|
|
|
|
|
I get this error when trying to incorporate some code that uses ATL's CStringT into my straight Win32 program:
<br />
IGCutter error LNK2019: unresolved external symbol "class ATL::CAtlStringMgr ATL::g_strmgr" (?g_strmgr@ATL@@3VCAtlStringMgr@1@A) referenced in function "public: static struct ATL::IAtlStringMgr * __cdecl ATL::StrTraitATL<char,class ATL::ChTraitsCRT<char> >::GetDefaultManager(void)" (?GetDefaultManager@?$StrTraitATL@DV?$ChTraitsCRT@D@ATL@@@ATL@@SAPAUIAtlStringMgr@2@XZ)<br />
My header has these files defined (many are probably unnecessary):
<br />
#include <atlbase.h><br />
#include <objbase.h><br />
extern CComModule _Module;<br />
#include <atlcom.h><br />
#include <atlapp.h><br />
#include <atlwin.h><br />
#include <atlframe.h><br />
#include <atlstr.h><br />
and I have "Static link to ATL" specified. What in the world am I doing wrong?
Thanks!
|
|
|
|
|
This is an update of the early semi-official announcement that WTL will go "open source". MS has set up licensing (legal stuff) to make this happen... read more...
Microsoft toys with open source[^]
Unlike Microsoft's previous shared-source efforts, the WTL plan would allow non-Microsoft staff to be involved in managing and developing WTL.
While reluctant to reveal details, Mr Kumar said a key concern was to provide more support for developers so they did not have to keep using the Yahoo! forum.
Mike M
WinInsider.com
|
|
|
|
|
I'm having difficulty using ATL Server's CBlobCache class. I'm trying to add an entry to the blob cache. The key is "v1" and the value is an int. The add method takes a *void for the actual data, so I figured I could push an int into it. Unfortunately, the mout int reads 6,500,000 . Is it a problem with my implementation of m_spBlobCache->Add or m_spBlobCache->GetData ?
HCACHEITEM hEntry;
// Get the IMemoryCache service from the ISAPI extension
if (FAILED(m_spServiceProvider->QueryService(__uuidof(IMemoryCache),
&m_spBlobCache)))
return HTTP_FAIL;
HRESULT hr = m_spBlobCache->LookupEntry("v1", &hEntry);
if (FAILED(hr) || !hEntry)
{
static const int s7 = 1;
int *pData = (int *)malloc(sizeof(int));
if (!pData)
return HTTP_FAIL;
*pData = s7;
CFileTime ft = CFileTime::GetCurrentTime() + CFileTime::Minute;
if(FAILED(m_spBlobCache->Add("v1", pData, (DWORD)sizeof(int), &ft,
m_hInstHandler, &hEntry, &g_MemoryCacheClient)))
{
m_spBlobCache->ReleaseEntry(hEntry);
return HTTP_FAIL;
}
}
if(FAILED(m_spBlobCache->GetData(hEntry, (void**)&mout, &dwSize)))
{
m_spBlobCache->ReleaseEntry(hEntry);
return HTTP_FAIL;
}
TIA
Ryan
|
|
|
|
|
Stupid Me...
This code is correct, I just messed up the request handling part. Well, now if anyone wants to know how to write an int to CBlobCache, they can use this snippet...
Ryan
|
|
|
|
|
HI,
I am looking for atlstr.h header file.
Can anyone point to download from?
Thanks
|
|
|
|
|
|
Hi,
In MSDN, there is a desccription of the interface ISimpleFrameSite:
Containers can also support container controls without supporting ISimpleFrameSite, although the behavior cannot be guaranteed. For this reason, a component category exists for SimpleFrameSite controls where the full functionality of this interface is required.
To support container controls without implementing ISimpleFrameSite, an ActiveX control container must:
Activate all controls at all times.
Reparent the contained controls to the hWnd of the containing control.
Remain the parent of the container control.
Now I create a composite ActiveX control, Can I implement interface ISimpleFrameSite:, and how?
Thank you!
|
|
|
|
|
When right clicking on taskbar there is a sub menu :"toolbars"
Clicking here, shows a list of existing toolbars and "add new bar..."
Selecting this option shows a dialog where it is possiple to specify an URL pointing to a web page ie: http:www.nanana.com/button.htm
All this is manual ! and works fine and easy (only one parameter) 
Is there a way (using VB or VBS) to create a deskband with a HTML content pointed by an URL.
This should look like : ...deskband.create url:="http:/...."
Obviously, there is a build in applet in the explorer that do the job a lot more simpler than creating 100% from scratch using ATL.
mailto:riberollesb@fsb.fr
|
|
|
|
|
hiya
I have a coclass that implements a dual interface (for use in C#), and I want to add a low level custom interface with the same methods for use by clients written in c++. But I have a couple of problems: firstly, C# picks the wrong method and refuses to compile unless I explicitly cast to the dual interface. Secondly, how do I implement methods from different interfaces with the same signature?
here's the code...
[<br />
object,<br />
uuid("32273BE2-CB15-47c2-BE09-DAA824A44916"),<br />
helpstring("IFuzzyLogic Interface"),<br />
pointer_default(unique),<br />
hidden<br />
]<br />
__interface IFuzzyLogic : IUnknown<br />
{<br />
[id(1), helpstring("method CreateModel")] HRESULT CreateModel([in] const char* szFileName, [out,retval] IFuzzyModel** ppModel);<br />
};<br />
<br />
[<br />
object,<br />
uuid("529A2190-6BB0-47A9-B1B4-001CD5981597"),<br />
dual, <br />
helpstring("IFuzzyLogicDual Interface"),<br />
pointer_default(unique)<br />
]<br />
__interface IFuzzyLogicDual : IDispatch<br />
{<br />
[id(1), helpstring("method CreateModel")] HRESULT CreateModel([in] BSTR sFileName, [out,retval] IFuzzyModelDual** ppModel);<br />
};
cheers,
Rob
|
|
|
|
|
Hi all,
Is WTL even available on MSDN/PlatformSDK anymore or is it really dead now ? I was planning on using it for a new app I'll be developing in VS.NET 2003, but I can't even find the SDK.
Thanks
|
|
|
|
|
|
I have an ATL project where I define several ATL COM objects. I would like to be able to create instances of these objects inside my module without having to use CoCreateInstance(). Everytime I try to do so it claims the classes are abstract because they do not define QueryInterface,AddRef...
Is there a way to create these objects internally without having to call CoCreateInstance?
Here's the logic to why I want to do this. I'm using a local class to catch some COM events. The local class implements a COM interface but itself is not a COM object. If I create this class with CoCreateInstance I will only be able to get the Event Sink interface back. The only way that I know of to call methods on this object would be to create a new interface for the object for the local methods I need. I would really like to avoid this. Here is a sample bit of code to show better what I'm trying to do
<br />
CEventSink : public _IEvents<br />
{<br />
public:<br />
void Setup(IEventSource *source);<br />
}<br />
<br />
...<br />
CEventSink sink;<br />
IEventSource *source;<br />
... CoCreatInstance for source...<br />
sink.Setup(source);<br />
Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n
|
|
|
|
|
|
|
I'm getting this error in ATL 7.0 trying to capture COM events from another library. I've researched this error on the web and it says to make sure you've included several header files. I've included all of hte header files
(atlbase,atlcom) and I've defined ATL_ATTRIBUTES above them. So far I've had no success in removing the error. Any ideas?
Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n
|
|
|
|
|
I fixed this problem in a hackish way. I created a new ATL project and copied all of the code over to the new project and it compiled fine.
The original project did not include ATL by default. I added it to the project settings later. The events suggest to me that in some way I failed to add ATL support properly. So what is the proper way to add ATL support to a project that formerly did not have it?
Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n
|
|
|
|
|
|
Array operations, like multiplying two arrays, is common in my work, and I therefore wrote a float array class, inheriting from STL-class vector. This approach slowed down the array multiplication with a factor of 150,(instantly back to the days of a 20 MHz computer, wiping out 20 years development!), if I compared it to multiplying two arrays created on the stack. Not using the vector template class, but still using a float array and functions defined inside a class, slows down multiplication with a factor of 15. What is the reason?
Bill
|
|
|
|
|
Probably the generation of extra copies of your matrix. Look in the net, there are a lot of implementations floating around. Also, I seem to remember an article in a fairly recent c++ users journal [^]
Who is 'General Failure'? And why is he reading my harddisk?!?
|
|
|
|
|
Hi,
I want to show line numbers on the left side of edit view. How to do that?
Thanks,
Derick.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
