How to use CEZCompressor (how to flush output data to output buffer) ?

[leslieoj]

Hi,

I am trying to use the CEZCompressor-class defines in EZCompressor.h to compress a descriptor. I do something like this:

// "this" is implementing MEZBufferManager,
// but the implementation I have left the methods "empty"
iCompressor=CEZCompressor::NewL(*this);
// InitializeL() of MEZBufferManager gets called by the above call

iCompressed=HBufC8::NewL(20000); // allocating space for output
TPtr8 ptrCompressed=iCompressed->Des();
iCompressor->SetOutput(ptrCompressed);
iCompressor->SetInput(*data); // data is HBufC8 with input data
// the input data in my tests is NOT longer than the output buffer

TBool def=iCompressor->DeflateL();
// NeedsInputL() of MEZBufferManager gets called in the above call
// Return value (def) is ETrue and by inspection the all
// avail input has been consumed, but there is only 2 bytes in
// total output (this might be the 2 bytes zlib header, I guess...)

// iCompressor->OutputDescriptor().Length() is also just 2

What am I doing wrong? Or what do I have to do, to get the full output flushed to the output buffer? I have tried additional calls to DeflateL() without any further result. Also, what does the return-value of DeflateL() mean?

Hope someone can give me some hints ;o)

Best regards,
Leslie

[vijayasreesv]

hi
which are the libraries to be linked for ezcompressor to work properly?is there any documentation related to ezcompressor .h or any links available


thanks in advance
vijayasree

[pinki121]

Hi
You use::

http://www.symbian.com/developer/tec...2C2/index.html




////////////////////////////////////////////
D:\SYMBIAN\7.0S\NOKIA_7710_SDK\SERIES90EX\DIALOG\SRC\Dialogappui.cpp(231) :

error C2665: 'NewLC' : none of the 2 overloads can convert parameter 1 from type 'class CDialogAppUi'

Dialogappui.obj - 1 error(s), 0 warning(s)

/////////////////////////////////////////
error is in this

void CDialogAppUi:isplayEditorDialogL()
{


CEZCompressor* iCompressor=CEZCompressor::NewLC(*this);





}

Thanks in advance..

[michaelemmens]

Does the class CDialogAppUi inherit from MEZBufferManager?

If it doesn't, the compiler won't be able to cast *this to the MEZBufferManager& required by CEZCompressor::NewLC.

You need to implement these four methods:

virtual void InitializeL(CEZZStream &aZStream);
virtual void NeedInputL(CEZZStream &aZStream);
virtual void NeedOutputL(CEZZStream &aZStream);
virtual void FinalizeL(CEZZStream &aZStream);

Alternatively, instantiate one of the supplied implementations of MEZBufferManager such as CEZFileToGzipBM.

Michael

[bestey]

How exactly do the BufferManagers work? What are the four API's supposed to do, and when are you supposed to call them?

I don't understand how the parameters are supposed to be generated as CEZZStream doesn't seem to have any kind of constructor.