Jeffrey, I'm not sure how Filter functions - but I thought its internal buffering (and therefore what it passes to the encryter & when) is not related to or dependent on the chunks that it is fed by the caller?
Also, it was not clear to me whether the OP needed each chunk to be encrypted *independently* - aka with a different key? Or am I barking up the wrong tree? On Thu, Jan 20, 2011 at 8:48 AM, Jeffrey Walton <[email protected]> wrote: > > > On Jan 19, 10:48 am, Graham Hemingway <[email protected]> > wrote: > > I have a program that compresses and encrypts thousands of individual > chunks > > of data. Each chunk must be compressed and encrypted separately. > > Everything works, but there must be a more optimal way to go about it > than > > I am currently. Here is the code I execute for each chunk to compress > it. > > > > // Create the compressor and load it up > > > > CryptoPP::ZlibCompressor compressor; > > > > compressor.Put( buffer, sizeB ); > > > > compressor.MessageEnd(); > > > > // Get the new size > > > > newSizeB = compressor.MaxRetrievable(); > > > > // Get the data > > > > compressor.Get( newBuffer, newSizeB); > > > > As you can see, I allocate a new compressor for each chunk. This is done > in > > a big loop, so I figured that I could "new" a compressor before the loop > to > > save on the cost of creating the compressor for each chunk. But, this > does > > not work. The first chunk that passes through the compressor works fine, > > but I always get a MaxRetrievable of 0 for all later chunks. I have > tried > > putting Flush(true) in all over the place but nothing seems to work yet. > > The same issue holds for the encryption pass. Any ideas? > Use filters. See for example, http://www.cryptopp.com/wiki/Filter. > > > One other thing. I am working on OS X 10.6 with XCode 3.2.2. I compiled > > Crypto++ as a static lib and everything went well. When I compile my app > I > > get two warnings from the included Crypto++ header files: > > > > ../../Include/cryptopp/algparam.h:26:0 > ../../Include/cryptopp/algparam.h:26: > > warning: unused variable 'cryptopp_assert_26' > > > > from line 26 of algparam.h > > > > ../../Include/cryptopp/algparam.h:322:0 > > ../../Include/cryptopp/algparam.h:322: warning: unused variable 'p' > > > > from line 322 of algparam.h > > > > I have seen some other posts along these lines. What should I change to > get > > rid of these? > http://www.cryptopp.com/wiki/Ios is written for iOS, but it should > apply to Mac OS X also: > > Another setting which is useful, but not required, is > -Wall -Wno-unused -Wno-unknown-pragmas under > GCC 4.2 Warnings, Other Warning Flags. Be careful > of -Wextra since GCC 4.2 will flag signed/unsigned > comparisons due to C++ templates. -Wno-type-limits > will suppress the spurious template warnings, but the > option is only available in GCC 4.3 and above. See > Missing "warning: comparison is always false due to > limited range of data type". > > Jeff > > -- > You received this message because you are subscribed to the "Crypto++ > Users" Google Group. > To unsubscribe, send an email to > [email protected]. > More information about Crypto++ and this group is available at > http://www.cryptopp.com. > -- Regards, Uri -- You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [email protected]. More information about Crypto++ and this group is available at http://www.cryptopp.com.
