Version: 3.1.1

#include <wx/zstream.h>

+ Inheritance diagram for wxZlibInputStream:

Detailed Description

This filter stream decompresses a stream that is in zlib or gzip format.

Note that reading the gzip format requires zlib version 1.2.1 or greater, (the builtin version does support gzip format).

The stream is not seekable, wxInputStream::SeekI returns wxInvalidOffset. Also wxStreamBase::GetSize() is not supported, it always returns 0.

Library:  wxBase
Category:  Archive support, Streams
See also
wxInputStream, wxZlibOutputStream.

Public Member Functions

 wxZlibInputStream (wxInputStream &stream, int flags=wxZLIB_AUTO)
 If the parent stream is passed as a pointer then the new filter stream takes ownership of it. More...
 
 wxZlibInputStream (wxInputStream *stream, int flags=wxZLIB_AUTO)
 If the parent stream is passed as a pointer then the new filter stream takes ownership of it. More...
 
bool SetDictionary (const char *data, size_t datalen)
 Sets the dictionary to the specified chunk of data. More...
 
bool SetDictionary (const wxMemoryBuffer &buf)
 Sets the dictionary to the specified chunk of data. More...
 
- Public Member Functions inherited from wxFilterInputStream
 wxFilterInputStream (wxInputStream &stream)
 Initializes a "filter" stream. More...
 
 wxFilterInputStream (wxInputStream *stream)
 Initializes a "filter" stream. More...
 
- Public Member Functions inherited from wxInputStream
 wxInputStream ()
 Creates a dummy input stream. More...
 
virtual ~wxInputStream ()
 Destructor. More...
 
virtual bool CanRead () const
 Returns true if some data is available in the stream right now, so that calling Read() wouldn't block. More...
 
virtual bool Eof () const
 Returns true after an attempt has been made to read past the end of the stream. More...
 
int GetC ()
 Returns the first character in the input queue and removes it, blocking until it appears if necessary. More...
 
virtual size_t LastRead () const
 Returns the last number of bytes read. More...
 
virtual char Peek ()
 Returns the first character in the input queue without removing it. More...
 
virtual wxInputStreamRead (void *buffer, size_t size)
 Reads the specified amount of bytes and stores the data in buffer. More...
 
wxInputStreamRead (wxOutputStream &stream_out)
 Reads data from the input queue and stores it in the specified output stream. More...
 
bool ReadAll (void *buffer, size_t size)
 Reads exactly the specified number of bytes into the buffer. More...
 
virtual wxFileOffset SeekI (wxFileOffset pos, wxSeekMode mode=wxFromStart)
 Changes the stream current position. More...
 
virtual wxFileOffset TellI () const
 Returns the current stream position or wxInvalidOffset if it's not available (e.g. More...
 
size_t Ungetch (const void *buffer, size_t size)
 This function is only useful in read mode. More...
 
bool Ungetch (char c)
 This function acts like the previous one except that it takes only one character: it is sometimes shorter to use than the generic function. More...
 
- Public Member Functions inherited from wxStreamBase
 wxStreamBase ()
 Creates a dummy stream object. More...
 
virtual ~wxStreamBase ()
 Destructor. More...
 
wxStreamError GetLastError () const
 This function returns the last error. More...
 
virtual wxFileOffset GetLength () const
 Returns the length of the stream in bytes. More...
 
virtual size_t GetSize () const
 This function returns the size of the stream. More...
 
virtual bool IsOk () const
 Returns true if no error occurred on the stream. More...
 
virtual bool IsSeekable () const
 Returns true if the stream supports seeking to arbitrary offsets. More...
 
void Reset (wxStreamError error=wxSTREAM_NO_ERROR)
 Resets the stream state. More...
 
bool operator! () const
 Returns the opposite of IsOk(). More...
 

Static Public Member Functions

static bool CanHandleGZip ()
 Returns true if zlib library in use can handle gzip compressed data. More...
 

Additional Inherited Members

- Protected Member Functions inherited from wxInputStream
size_t OnSysRead (void *buffer, size_t bufsize)=0
 Internal function. More...
 
- Protected Member Functions inherited from wxStreamBase
virtual wxFileOffset OnSysSeek (wxFileOffset pos, wxSeekMode mode)
 Internal function. More...
 
virtual wxFileOffset OnSysTell () const
 Internal function. More...
 

Constructor & Destructor Documentation

wxZlibInputStream::wxZlibInputStream ( wxInputStream stream,
int  flags = wxZLIB_AUTO 
)

If the parent stream is passed as a pointer then the new filter stream takes ownership of it.

If it is passed by reference then it does not.

The flags wxZLIB_ZLIB and wxZLIB_GZIP specify whether the input data is in zlib or gzip format. If wxZLIB_AUTO is used, then zlib will autodetect the stream type, this is the default.

If flags is wxZLIB_NO_HEADER, then the data is assumed to be a raw deflate stream without either zlib or gzip headers. This is a lower level mode, which is not usually used directly. It can be used to read a raw deflate stream embedded in a higher level protocol.

The values of the wxZLibFlags enumeration can be used.

wxZlibInputStream::wxZlibInputStream ( wxInputStream stream,
int  flags = wxZLIB_AUTO 
)

If the parent stream is passed as a pointer then the new filter stream takes ownership of it.

If it is passed by reference then it does not.

The flags wxZLIB_ZLIB and wxZLIB_GZIP specify whether the input data is in zlib or gzip format. If wxZLIB_AUTO is used, then zlib will autodetect the stream type, this is the default.

If flags is wxZLIB_NO_HEADER, then the data is assumed to be a raw deflate stream without either zlib or gzip headers. This is a lower level mode, which is not usually used directly. It can be used to read a raw deflate stream embedded in a higher level protocol.

The values of the wxZLibFlags enumeration can be used.

Member Function Documentation

static bool wxZlibInputStream::CanHandleGZip ( )
static

Returns true if zlib library in use can handle gzip compressed data.

bool wxZlibInputStream::SetDictionary ( const char *  data,
size_t  datalen 
)

Sets the dictionary to the specified chunk of data.

This can improve compression rate but note that the dictionary has to be the same when you deflate the data as when you inflate the data, otherwise you will inflate corrupted data.

Returns true if the dictionary was successfully set.

bool wxZlibInputStream::SetDictionary ( const wxMemoryBuffer buf)

Sets the dictionary to the specified chunk of data.

This can improve compression rate but note that the dictionary has to be the same when you deflate the data as when you inflate the data, otherwise you will inflate corrupted data.

Returns true if the dictionary was successfully set.