Zipios++
Public Member Functions | Protected Member Functions | Protected Attributes
zipios::DeflateOutputStreambuf Class Reference

DeflateOutputStreambuf is an output stream filter, that deflates the data that is written to it before it passes it on to the output stream it is attached to. More...

#include <deflateoutputstreambuf.h>

Inheritance diagram for zipios::DeflateOutputStreambuf:
Inheritance graph
[legend]

List of all members.

Public Member Functions

 DeflateOutputStreambuf (streambuf *outbuf, bool user_init=false, bool del_outbuf=false)
 DeflateOutputStreambuf constructor.
virtual ~DeflateOutputStreambuf ()
 Destructor.
bool init (int comp_level=6)
bool closeStream ()
uint32 getCrc32 () const
 Returns the CRC32 for the current stream.
uint32 getCount () const
 Returns the number of bytes written to the streambuf, that has been processed from the input buffer by the compressor.
- Public Member Functions inherited from zipios::FilterOutputStreambuf
 FilterOutputStreambuf (streambuf *outbuf, bool del_outbuf=false)
 Constructor.
virtual ~FilterOutputStreambuf ()
 Destructor.

Protected Member Functions

virtual int overflow (int c=EOF)
virtual int sync ()
bool flushOutvec ()
 Flushes _outvec and updates _zs.next_out and _zs.avail_out.
void endDeflation ()
 Flushes the remaining data in the zlib buffers, after which the only possible operations are deflateEnd() or deflateReset().

Protected Attributes

const int _invecsize
vector< char > _invec
const int _outvecsize
vector< char > _outvec
uint32 _crc32
uint32 _overflown_bytes
- Protected Attributes inherited from zipios::FilterOutputStreambuf
streambuf * _outbuf
bool _del_outbuf

Detailed Description

DeflateOutputStreambuf is an output stream filter, that deflates the data that is written to it before it passes it on to the output stream it is attached to.

Deflation/Inflation is a compression/decompression method used in gzip and zip. The zlib library is used to perform the actual deflation, this class only wraps the functionality in an output stream filter.

Definition at line 25 of file deflateoutputstreambuf.h.


Constructor & Destructor Documentation

zipios::DeflateOutputStreambuf::DeflateOutputStreambuf ( streambuf *  outbuf,
bool  user_init = false,
bool  del_outbuf = false 
)
explicit

DeflateOutputStreambuf constructor.

Parameters:
outbufthe streambuf to use for output.
user_initIf false user must invoke init() before writing any data. (ZipOutputStreambuf needs to do this)
del_outbufif true is specified outbuf will be deleted, when the DeflateOutputStreambuf is destructed.

Definition at line 18 of file deflateoutputstreambuf.cpp.

zipios::DeflateOutputStreambuf::~DeflateOutputStreambuf ( )
virtual

Destructor.

Definition at line 43 of file deflateoutputstreambuf.cpp.


Member Function Documentation

void zipios::DeflateOutputStreambuf::endDeflation ( )
protected

Flushes the remaining data in the zlib buffers, after which the only possible operations are deflateEnd() or deflateReset().

Definition at line 173 of file deflateoutputstreambuf.cpp.

bool zipios::DeflateOutputStreambuf::flushOutvec ( )
protected

Flushes _outvec and updates _zs.next_out and _zs.avail_out.

Definition at line 162 of file deflateoutputstreambuf.cpp.

uint32 zipios::DeflateOutputStreambuf::getCount ( ) const
inline

Returns the number of bytes written to the streambuf, that has been processed from the input buffer by the compressor.

After closeStream() has been called this number is the total number of bytes written to the stream.

Definition at line 55 of file deflateoutputstreambuf.h.

uint32 zipios::DeflateOutputStreambuf::getCrc32 ( ) const
inline

Returns the CRC32 for the current stream.

The returned value is the CRC for the data that has been compressed already (due to a call to overflow()). As DeflateOutputStreambuf may buffer an arbitrary amount of bytes until closeStream() has been invoked, the returned value is not very useful before closeStream() has been called.

Definition at line 49 of file deflateoutputstreambuf.h.


The documentation for this class was generated from the following files: