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Why don't you call GetLastError on PaintDesktop failure?
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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or if you're lazy, add @err,hr to your watch window
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Can anyone help me with example code where u can use (vector, queue, dequeue , map techniques)
Thanks Stuart Dootson &; Superman !
I will be receiving certain amount of packets but I am not sure exactly how much. There will no memory problem as certainly its being taken under consideration that the received packets will be at certain limit it will not exceed.
whats the difference between using vector versus dequeue or queue technique.
I am explaining my scenario . I have reader thread that will do blocking read and once it receives the first packet which will be of 20W with 1W header with it.. I need to calculate checksum of the 20W packet received. Than I need to read certain fields and need to decide where it needs to be buffered. Before buffering these packets I need to strip off the 1W header. Once the buffering is complete say I might receieve 500 packets of size 20Word. After I stop receving the packets. I need to analyze the packets that being buffered. And these packets are of 2 types theere might be 2W packet and 260W packet or partial packet and each of these packet will have header so. first I need to read the packet header of the first received packet inthe buffer and base don that I need to dispatch those packets to its destined location or hand over to the designated handler.
So confusion is whats the best efficient technique I should use. Using simple array is not best option so thought of asking here. Also how do Istrip off the header from the packet.
Any help woul dbe appreciated. I have just started coding but have not really much coded in C++ .. I am learning by dng google or reading previos discussion here on forum
THANKS!!!!
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You should probably use deque. In my opinion it would be best suited for your application requirments. A Microsoft sample of deque:
INFO: STL Sample for deque::push_back and deque::pop_back Functions[^]
A in-depth deque analysis by a codeproject member:
An In-Depth Study of the STL Deque Container[^]
resolvequestion wrote: whats the difference between using vector versus dequeue or queue technique
This is not really the type of information that is obtained through a forum. You should probably invest a few hours and research the difference between the STL containers. Here is a good place to start:
STL Container Comparison[^]
STL Containers[^]
resolvequestion wrote: Also how do I strip off the header from the packet.
WORD packet_buffer[20];
WORD packet_head = packet_buffer[0];
WORD *piStripped = &packet_buffer[1];
BYTE *pbStripped = (BYTE *)&packet_buffer[1];
resolvequestion wrote: Any help woul dbe appreciated. I have just started coding but have not really much coded in C+
Excellent, in my opinion codeproject is the best programming resource on the internet.
Good luck,
-David Delaune
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resolvequestion wrote: whats the difference between using vector versus dequeue or queue technique
Each of the STL containers are optimized for certain types of operations.
Read more about it here - STL Containers[^]
For example, vector is optimized for random access to any of its elements.
A deque is optimized for insertions and removal of elements at both its ends.
As suggested by Stuart in your earlier post, a deque will be perfect for your needs.
«_Superman_»
I love work. It gives me something to do between weekends.
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Dear friends,
I am looking for C++ programs of wavelet transform for seismic waves. Although, I can do wavelet transform with Matcad, I like to get an independent program.
Thanks
Yours
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Have you already looked at this page [^]?
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Thank you. I will give a try. This one seems for image processing, I hope it will work for seismic waves.
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I wish to get the project files and link and run it.
Please advise.
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I guess I have a keen sense for the obvious but I would try the download link(s) on the page he linked to.
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The download does not include a project file. So I still do not know how to compile those library files into a project.
I need to process seismic waves from geophysics survey.
Please help
Thanks
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Hi folks,
I'm looking for non-template based library that provides common data structures (queue, vector, etc). The non-template part is crucial since I'm doing embedded system and I need the code to be portable to older EC++ compilers.
Ideas? Commercial or non-commercial suggestions accepted!
Thanks in advance!
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A C generic container library is probably what you're looking for. This StackOverflow page[^] seems relevant?
Similarly, this page[^] describes generic containers in C.
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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Hi all,
i have a big annoying problem with visual studio 6:
in my projects when i go in debug mode i cannot see the value of some variables in watch window,
simply they appear uninitialized or empty, but i know they are initialized!
i.e. if i want to see the value inside variable Y i have to write the following code:
int x=Y;
only in this way i can see the x variable in watch window with its value...
i have formatted my PC but cannot solve yet this problem...
anybody knows this kind of problems?
i hope i've explained enough...
Thanks to all in advance...
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Are you actually using the Debug configuration build? Because the symptoms you describe sound just like trying to debug a Release configuration build with optimisations turned on...
But then the compiler would optimise away the assignment of Y to x as ineffective. Hmmm.
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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yes i'm in debug mode...
i just cannot find any mention of this kind of problem around the web...
i'm using an AMD Athlon 64 x2 4800+ with 2GB of RAM and Win XP SP3
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You might like to try Windbg[^] for debugging, see if that gives better results?
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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I've also found VC6 terrible at watching global variables...
Also, deleting the ncb file helps a lot with almost everything!
Iain.
I have now moved to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), or need cotract work done, give me a job! http://cv.imcsoft.co.uk/[ ^]
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Verify whether you are watching "Auto", "Locals" or "this".
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seems very strange, i've tryed on another PC the same code and i got same results...so is not my HW i suppose, but mine and other PC are
with dual core CPUs...i got a amd athlon X2 processor and other is intel core 2 duo....i will try on a single core machine...maybe visual c++ 6
got some troubles with today multicore cpus? if it's true what i can do?....
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I use VC++ 6 on a Core 2 duo and don't have a problem. Wish I had a solution for you.
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Hi,
I have a code that generates hash from data stream using following calls:
CryptAcquireContext(&hDummyProv, NULL, NULL, PROV_RSA_FULL, 0)
CryptCreateHash()
CryptHashData()
CryptGetHashParam()
CryptDestroyHash()
I am trying to use the hash blob to generate signed message using following calls:
CertEnumCertificatesInStore
CertGetCertificateContextProperty ()
CryptAcquireContext(
&hProv,
pProvInfoData->pwszContainerName,
pProvInfoData->pwszProvName,
PROV_RSA_FULL,
0)
CryptCreateHash() – get new hash handle this time from CSP
CryptSetHashParam() – update hash handle with message digest prepared earlier
CryptMsgOpenToEncode(
MY_ENCODING_TYPE,
CMSG_DETACHED_FLAG | CMSG_AUTHENTICATED_ATTRIBUTES_FLAG,
CMSG_SIGNED,
&SignedEncodedInfo,
0,
NULL)
Everything works fine until I retrieve the szOID_RSA_messageDigest property to compare with previously generated hash. I get a different value than I set.
Comment: I must use a call to CryptMsgOpenToEncode to generate encrypted message signed by A CSP.
What am I doing wrong?
Thanks for helping me,
Lilach
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Hi Lilach,
Unfortunately you have not provided enough information to conclusively identify the cause of your problem. The only thing that comes to mind is that I dont see your mention of calling CryptMsgUpdate.
With the limited information provided the only thing I can think of is to point you towards an MSDN sample which closely matches your requirements:
Example C Program: Encoding an Enveloped, Signed Message[^]
Best Wishes,
-David Delaune
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Hi David,
I added a call to CryptMsgUpdate() as you suggested. The problem is that when I decode the resulted message, the content contains different message digest. In fact, I think it is the digest of an empty message.
Here is the message digest I got:
DA 39 A3 EE 5E 6B 4B 0D 32 55 BF EF 95 60 18 90 AF D8 07 09
Here is the relevant code:
CMSG_SIGNED_ENCODE_INFO signedEncodedInfo;
HCRYPTPROV hHash = NULL;
// ... here singedEncodedInfo is initiated
// create a hash object.
if (!CryptCreateHash(d_hCryptProv, CALG_SHA1, 0, 0, &hHash))
{
throw( GetLastError());
}
// set hash data to hash handle
// pHashBytes is a pointer to bytes array containing
// hashed data
if (!CryptSetHashParam(hHash, HP_HASHVAL, pHashBytes, 0))
{
throw(GetLastError());
}
// initiate encoded message
d_hMsg = CryptMsgOpenToEncode(MY_ENCODING_TYPE,
CMSG_DETACHED_FLAG | MSG_AUTHENTICATED_ATTRIBUTES_FLAG,
MSG_SIGNED,
&SignedEncodedInfo,
0,
NULL);
if (!CryptMsgUpdate( d_hMsg, NULL, 0, TRUE ))
{
throw(GetLastError());
}
Do you have an idea what is wrong?
Thanks,
Lilach
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What do you mean when you say decode? Are you trying to decode a SHA1 hash back into the original message? SHA1 is a one way hash, it cannot be decoded back into the original message!
Best Wishes,
-David Delaune
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