gzfilebuf Class Reference

Gzipped file stream buffer class. More...

#include <zfstream.h>

Inheritance diagram for gzfilebuf:

Public Member Functions
gzfilebuf *	attach (int fd, std::ios_base::openmode mode)
	Attach to already open gzipped file. More...
gzfilebuf *	attach (int fd, std::ios_base::openmode mode)
	Attach to already open gzipped file. More...
gzfilebuf *	attach (int file_descriptor, int io_mode)
gzfilebuf *	attach (int file_descriptor, int io_mode)
gzfilebuf *	close ()
gzfilebuf *	close ()
gzfilebuf *	close ()
	Close gzipped file. More...
gzfilebuf *	close ()
	Close gzipped file. More...
	gzfilebuf ()
	gzfilebuf ()
	gzfilebuf ()
	gzfilebuf ()
int	is_open () const
int	is_open () const
bool	is_open () const
	Check if file is open. More...
bool	is_open () const
	Check if file is open. More...
gzfilebuf *	open (const char *name, int io_mode)
gzfilebuf *	open (const char *name, int io_mode)
gzfilebuf *	open (const char *name, std::ios_base::openmode mode)
	Open gzipped file. More...
gzfilebuf *	open (const char *name, std::ios_base::openmode mode)
	Open gzipped file. More...
virtual streampos	seekoff (streamoff, ios::seek_dir, int)
virtual streampos	seekoff (streamoff, ios::seek_dir, int)
int	setcompression (int comp_level, int comp_strategy=Z_DEFAULT_STRATEGY)
	Set compression level and strategy on the fly. More...
int	setcompression (int comp_level, int comp_strategy=Z_DEFAULT_STRATEGY)
	Set compression level and strategy on the fly. More...
int	setcompressionlevel (int comp_level)
int	setcompressionlevel (int comp_level)
int	setcompressionstrategy (int comp_strategy)
int	setcompressionstrategy (int comp_strategy)
virtual int	sync ()
virtual int	sync ()
virtual	~gzfilebuf ()
virtual	~gzfilebuf ()
virtual	~gzfilebuf ()
virtual	~gzfilebuf ()

Protected Member Functions
bool	open_mode (std::ios_base::openmode mode, char *c_mode) const
	Convert ios open mode int to mode string used by zlib. More...
bool	open_mode (std::ios_base::openmode mode, char *c_mode) const
	Convert ios open mode int to mode string used by zlib. More...
virtual int	overflow (int=EOF)
virtual int	overflow (int=EOF)
virtual int_type	overflow (int_type c=traits_type::eof())
	Write put area to gzipped file. More...
virtual int_type	overflow (int_type c=traits_type::eof())
	Write put area to gzipped file. More...
virtual std::streambuf *	setbuf (char_type *p, std::streamsize n)
	Installs external stream buffer. More...
virtual std::streambuf *	setbuf (char_type *p, std::streamsize n)
	Installs external stream buffer. More...
virtual std::streamsize	showmanyc ()
	Number of characters available in stream buffer. More...
virtual std::streamsize	showmanyc ()
	Number of characters available in stream buffer. More...
virtual int	sync ()
	Flush stream buffer to file. More...
virtual int	sync ()
	Flush stream buffer to file. More...
virtual int	underflow ()
virtual int	underflow ()
virtual int_type	underflow ()
	Fill get area from gzipped file. More...
virtual int_type	underflow ()
	Fill get area from gzipped file. More...

Private Member Functions
void	disable_buffer ()
	Destroy internal buffer. More...
void	disable_buffer ()
	Destroy internal buffer. More...
void	enable_buffer ()
	Allocate internal buffer. More...
void	enable_buffer ()
	Allocate internal buffer. More...
int	fillbuf ()
int	fillbuf ()
int	flushbuf ()
int	flushbuf ()

Private Attributes
char_type *	buffer
	Stream buffer. More...
std::streamsize	buffer_size
	Stream buffer size. More...
gzFile	file
std::ios_base::openmode	io_mode
short	mode
bool	own_buffer
	True if this object owns stream buffer. More...
bool	own_fd
	True if this object owns file descriptor. More...
short	own_file_descriptor

Detailed Description

Gzipped file stream buffer class.

This class implements basic_filebuf for gzipped files. It doesn't yet support seeking (allowed by zlib but slow/limited), putback and read/write access (tricky). Otherwise, it attempts to be a drop-in replacement for the standard file streambuf.

Definition at line 8 of file bloaty/third_party/zlib/contrib/iostream/zfstream.h.

Constructor & Destructor Documentation

gzfilebuf() [1/4]

gzfilebuf::gzfilebuf

(

)

Definition at line 4 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

~gzfilebuf() [1/4]

gzfilebuf::~gzfilebuf ( )

virtual

Definition at line 10 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

gzfilebuf() [2/4]

gzfilebuf::gzfilebuf

(

)

~gzfilebuf() [2/4]

virtual gzfilebuf::~gzfilebuf ( )

virtual

gzfilebuf() [3/4]

gzfilebuf::gzfilebuf

(

)

~gzfilebuf() [3/4]

virtual gzfilebuf::~gzfilebuf ( )

virtual

gzfilebuf() [4/4]

gzfilebuf::gzfilebuf

(

)

~gzfilebuf() [4/4]

virtual gzfilebuf::~gzfilebuf ( )

virtual

Member Function Documentation

attach() [1/4]

gzfilebuf * gzfilebuf::attach	(	int	fd,
		std::ios_base::openmode	mode
	)

Attach to already open gzipped file.

Parameters

fd	File descriptor.
mode	Open mode flags.

Returns

this on success, NULL on failure.

Definition at line 79 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

attach() [2/4]

gzfilebuf* gzfilebuf::attach	(	int	fd,
		std::ios_base::openmode	mode
	)

Attach to already open gzipped file.

Parameters

fd	File descriptor.
mode	Open mode flags.

Returns

this on success, NULL on failure.

attach() [3/4]

gzfilebuf * gzfilebuf::attach	(	int	file_descriptor,
		int	io_mode
	)

Definition at line 60 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

attach() [4/4]

gzfilebuf* gzfilebuf::attach	(	int	file_descriptor,
		int	io_mode
	)

close() [1/4]

gzfilebuf * gzfilebuf::close

(

)

Definition at line 102 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

close() [2/4]

gzfilebuf* gzfilebuf::close

(

)

close() [3/4]

gzfilebuf* gzfilebuf::close

(

)

Close gzipped file.

Returns

this on success, NULL on failure.

close() [4/4]

gzfilebuf* gzfilebuf::close

(

)

Close gzipped file.

Returns

this on success, NULL on failure.

disable_buffer() [1/2]

void gzfilebuf::disable_buffer ( )

private

Destroy internal buffer.

This function is safe to call multiple times. It will ensure that the internal buffer is deallocated if it exists. In any case, it will also reset the buffer pointers.

disable_buffer() [2/2]

void gzfilebuf::disable_buffer ( )

private

Destroy internal buffer.

This function is safe to call multiple times. It will ensure that the internal buffer is deallocated if it exists. In any case, it will also reset the buffer pointers.

Definition at line 347 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

enable_buffer() [1/2]

void gzfilebuf::enable_buffer ( )

private

Allocate internal buffer.

This function is safe to call multiple times. It will ensure that a proper internal buffer exists if it is required. If the buffer already exists or is external, the buffer pointers will be reset to their original state.

enable_buffer() [2/2]

void gzfilebuf::enable_buffer ( )

private

Allocate internal buffer.

This function is safe to call multiple times. It will ensure that a proper internal buffer exists if it is required. If the buffer already exists or is external, the buffer pointers will be reset to their original state.

Definition at line 308 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

fillbuf() [1/2]

int gzfilebuf::fillbuf ( )

private

fillbuf() [2/2]

int gzfilebuf::fillbuf ( )

private

Definition at line 235 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

flushbuf() [1/2]

int gzfilebuf::flushbuf ( )

private

Definition at line 218 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

flushbuf() [2/2]

int gzfilebuf::flushbuf ( )

private

is_open() [1/4]

int gzfilebuf::is_open ( ) const

inline

Definition at line 22 of file bloaty/third_party/zlib/contrib/iostream/zfstream.h.

is_open() [2/4]

int gzfilebuf::is_open ( ) const

inline

Definition at line 22 of file zlib/contrib/iostream/zfstream.h.

is_open() [3/4]

bool gzfilebuf::is_open ( ) const

inline

Check if file is open.

Returns

True if file is open.

Definition at line 57 of file zlib/contrib/iostream3/zfstream.h.

is_open() [4/4]

bool gzfilebuf::is_open ( ) const

inline

Check if file is open.

Returns

True if file is open.

Definition at line 57 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

open() [1/4]

gzfilebuf * gzfilebuf::open	(	const char *	name,
		int	io_mode
	)

Definition at line 18 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

open() [2/4]

gzfilebuf* gzfilebuf::open	(	const char *	name,
		int	io_mode
	)

open() [3/4]

gzfilebuf* gzfilebuf::open	(	const char *	name,
		std::ios_base::openmode	mode
	)

Open gzipped file.

Parameters

name	File name.
mode	Open mode flags.

Returns

this on success, NULL on failure.

open() [4/4]

gzfilebuf * gzfilebuf::open	(	const char *	name,
		std::ios_base::openmode	mode
	)

Open gzipped file.

Parameters

name	File name.
mode	Open mode flags.

Returns

this on success, NULL on failure.

Definition at line 51 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

open_mode() [1/2]

bool gzfilebuf::open_mode ( std::ios_base::openmode  mode, char *  c_mode  ) const

protected

Convert ios open mode int to mode string used by zlib.

Returns

True if valid mode flag combination.

Definition at line 131 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

open_mode() [2/2]

bool gzfilebuf::open_mode ( std::ios_base::openmode  mode, char *  c_mode  ) const

protected

Convert ios open mode int to mode string used by zlib.

Returns

True if valid mode flag combination.

overflow() [1/4]

virtual int gzfilebuf::overflow ( int  = EOF )

protectedvirtual

overflow() [2/4]

int gzfilebuf::overflow ( int  c = EOF )

protectedvirtual

Definition at line 173 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

overflow() [3/4]

virtual int_type gzfilebuf::overflow ( int_type  c = traits_type::eof() )

protectedvirtual

Write put area to gzipped file.

Parameters

c	Extra character to add to buffer contents.

Returns

Non-EOF on success, EOF on error.

This actually writes characters in stream buffer to gzipped file. With unbuffered output this is done one character at a time.

overflow() [4/4]

gzfilebuf::int_type gzfilebuf::overflow ( int_type  c = traits_type::eof() )

protectedvirtual

Write put area to gzipped file.

Parameters

c	Extra character to add to buffer contents.

Returns

Non-EOF on success, EOF on error.

This actually writes characters in stream buffer to gzipped file. With unbuffered output this is done one character at a time.

Definition at line 214 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

seekoff() [1/2]

virtual streampos gzfilebuf::seekoff ( streamoff  , ios::seek_dir  , int    )

virtual

seekoff() [2/2]

streampos gzfilebuf::seekoff ( streamoff  off, ios::seek_dir  dir, int  which  )

virtual

Definition at line 129 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

setbuf() [1/2]

std::streambuf * gzfilebuf::setbuf ( char_type *  p, std::streamsize  n  )

protectedvirtual

Installs external stream buffer.

Parameters

p	Pointer to char buffer.
n	Size of external buffer.

Returns

this on success, NULL on failure.

Call setbuf(0,0) to enable unbuffered output.

Definition at line 266 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

setbuf() [2/2]

virtual std::streambuf* gzfilebuf::setbuf ( char_type *  p, std::streamsize  n  )

protectedvirtual

Installs external stream buffer.

Parameters

p	Pointer to char buffer.
n	Size of external buffer.

Returns

this on success, NULL on failure.

Call setbuf(0,0) to enable unbuffered output.

setcompression() [1/2]

int gzfilebuf::setcompression	(	int	comp_level,
		int	comp_strategy = Z_DEFAULT_STRATEGY
	)

Set compression level and strategy on the fly.

Parameters

comp_level	Compression level (see zlib.h for allowed values)
comp_strategy	Compression strategy (see zlib.h for allowed values)

Returns

Z_OK on success, Z_STREAM_ERROR otherwise.

Unfortunately, these parameters cannot be modified separately, as the previous zfstream version assumed. Since the strategy is seldom changed, it can default and setcompression(level) then becomes like the old setcompressionlevel(level).

setcompression() [2/2]

int gzfilebuf::setcompression	(	int	comp_level,
		int	comp_strategy = Z_DEFAULT_STRATEGY
	)

Set compression level and strategy on the fly.

Parameters

comp_level	Compression level (see zlib.h for allowed values)
comp_strategy	Compression strategy (see zlib.h for allowed values)

Returns

Z_OK on success, Z_STREAM_ERROR otherwise.

Unfortunately, these parameters cannot be modified separately, as the previous zfstream version assumed. Since the strategy is seldom changed, it can default and setcompression(level) then becomes like the old setcompressionlevel(level).

Definition at line 43 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

setcompressionlevel() [1/2]

int gzfilebuf::setcompressionlevel

(

int

comp_level

)

Definition at line 116 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

setcompressionlevel() [2/2]

int gzfilebuf::setcompressionlevel

(

int

comp_level

)

setcompressionstrategy() [1/2]

int gzfilebuf::setcompressionstrategy

(

int

comp_strategy

)

setcompressionstrategy() [2/2]

int gzfilebuf::setcompressionstrategy

(

int

comp_strategy

)

Definition at line 122 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

showmanyc() [1/2]

virtual std::streamsize gzfilebuf::showmanyc ( )

protectedvirtual

Number of characters available in stream buffer.

Returns

Number of characters.

This indicates number of characters in get area of stream buffer. These characters can be read without accessing the gzipped file.

showmanyc() [2/2]

std::streamsize gzfilebuf::showmanyc ( )

protectedvirtual

Number of characters available in stream buffer.

Returns

Number of characters.

This indicates number of characters in get area of stream buffer. These characters can be read without accessing the gzipped file.

Definition at line 169 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.cc.

sync() [1/4]

virtual int gzfilebuf::sync ( )

virtual

sync() [2/4]

int gzfilebuf::sync ( )

virtual

Definition at line 206 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

sync() [3/4]

virtual int gzfilebuf::sync ( )

protectedvirtual

Flush stream buffer to file.

Returns

0 on success, -1 on error.

This calls underflow(EOF) to do the job.

sync() [4/4]

virtual int gzfilebuf::sync ( )

protectedvirtual

Flush stream buffer to file.

Returns

0 on success, -1 on error.

This calls underflow(EOF) to do the job.

underflow() [1/4]

virtual int gzfilebuf::underflow ( )

protectedvirtual

underflow() [2/4]

gzfilebuf::int_type gzfilebuf::underflow ( )

protectedvirtual

Definition at line 135 of file bloaty/third_party/zlib/contrib/iostream/zfstream.cpp.

underflow() [3/4]

virtual int_type gzfilebuf::underflow ( )

protectedvirtual

Fill get area from gzipped file.

Returns

First character in get area on success, EOF on error.

This actually reads characters from gzipped file to stream buffer. Always buffered.

underflow() [4/4]

virtual int_type gzfilebuf::underflow ( )

protectedvirtual

Fill get area from gzipped file.

Returns

First character in get area on success, EOF on error.

This actually reads characters from gzipped file to stream buffer. Always buffered.

Member Data Documentation

buffer

char_type * gzfilebuf::buffer

private

Stream buffer.

For simplicity this remains allocated on the free store for the entire life span of the gzfilebuf object, unless replaced by setbuf.

Definition at line 207 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

buffer_size

std::streamsize gzfilebuf::buffer_size

private

Stream buffer size.

Defaults to system default buffer size (typically 8192 bytes). Modified by setbuf.

Definition at line 215 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

file

gzFile gzfilebuf::file

private

Underlying file pointer.

Definition at line 35 of file bloaty/third_party/zlib/contrib/iostream/zfstream.h.

io_mode

std::ios_base::openmode gzfilebuf::io_mode

private

Mode in which file was opened.

Definition at line 191 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

mode

short gzfilebuf::mode

private

Definition at line 36 of file bloaty/third_party/zlib/contrib/iostream/zfstream.h.

own_buffer

bool gzfilebuf::own_buffer

private

True if this object owns stream buffer.

This makes the class responsible for deleting the buffer upon destruction.

Definition at line 223 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

own_fd

bool gzfilebuf::own_fd

private

True if this object owns file descriptor.

This makes the class responsible for closing the file upon destruction.

Definition at line 199 of file bloaty/third_party/zlib/contrib/iostream3/zfstream.h.

own_file_descriptor

short gzfilebuf::own_file_descriptor

private

Definition at line 37 of file bloaty/third_party/zlib/contrib/iostream/zfstream.h.

---

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

• bloaty/third_party/zlib/contrib/iostream/zfstream.h
• bloaty/third_party/zlib/contrib/iostream/zfstream.cpp
• bloaty/third_party/zlib/contrib/iostream3/zfstream.cc