Save the output stream buffer. More...

#include <gzipoutputstreambuf.hpp>

Inheritance diagram for zipios::GZIPOutputStreambuf:

[legend]

Collaboration diagram for zipios::GZIPOutputStreambuf:

[legend]

Public Member Functions
	GZIPOutputStreambuf (std::streambuf *outbuf, FileEntry::CompressionLevel compression_level)
	Initialize a GZIPOutputStreambuf object.

virtual	~GZIPOutputStreambuf () override
	Ensures that the stream gets closed properly.

void	close ()
	Close the stream.

void	closeStream ()
	Closing the stream.

void	finish ()
	Finishes the compression.

uint32_t	getCrc32 () const
	Get the CRC32 of the file.

size_t	getSize () const
	Retrieve the size of the file deflated.

bool	init (FileEntry::CompressionLevel compression_level)
	Initialize the zlib library.

void	setComment (std::string const &comment)

void	setFilename (std::string const &filename)

Protected Member Functions
virtual int	overflow (int c=EOF) override
	Handle an overflow.

virtual int	sync () override
	Synchronize the buffer.

Protected Attributes
uint32_t	m_crc32 = 0

std::vector< char >	m_invec = std::vector<char>()

std::streambuf *	m_outbuf = nullptr

uint32_t	m_overflown_bytes = 0

Private Member Functions
void	endDeflation ()
	End deflation of current file.

void	flushOutvec ()
	Flush the cached output data.

void	writeHeader ()

void	writeInt (uint32_t i)

void	writeTrailer ()

Private Attributes
std::string	m_comment = std::string()

std::string	m_filename = std::string()

bool	m_open = false

std::vector< char >	m_outvec = std::vector<char>()

z_stream	m_zs = z_stream()

bool	m_zs_initialized = false

Detailed Description

This class is used to output the data of a file in a gzip stream including the necessary header and footer.

Definition at line 41 of file gzipoutputstreambuf.hpp.

Constructor & Destructor Documentation

◆ GZIPOutputStreambuf()

zipios::GZIPOutputStreambuf::GZIPOutputStreambuf	(	std::streambuf *	outbuf,
		FileEntry::CompressionLevel	compression_level
	)

A newly constructed GZIPOutputStreambuf is ready to accept data.

Parameters

[in,out]	outbuf	The streambuf to use for output.
[in]	compression_level	The compression level to use to compress.

Definition at line 54 of file gzipoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::init().

◆ ~GZIPOutputStreambuf()

zipios::GZIPOutputStreambuf::~GZIPOutputStreambuf ( )

overridevirtual

This function makes sure that the stream gets closed properly which means that the compress terminates by calling finish() and the streams get closed.

Definition at line 70 of file gzipoutputstreambuf.cpp.

References finish().

Member Function Documentation

◆ close()

void zipios::GZIPOutputStreambuf::close ( )

This function ensures that the streams get closed.

Definition at line 92 of file gzipoutputstreambuf.cpp.

References finish().

◆ closeStream()

void zipios::DeflateOutputStreambuf::closeStream ( )

inherited

This function is expected to be called once the stream is getting closed (the buffer is destroyed.)

It ensures that the zlib library last few bytes get flushed and then mark the class as closed.

Note that this function can be called to close the current zlib library stream and start a new one. It is actually called from the putNextEntry() function (via the closeEntry() function.)

Definition at line 200 of file deflateoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::endDeflation(), zipios::DeflateOutputStreambuf::m_zs, and zipios::DeflateOutputStreambuf::m_zs_initialized.

Referenced by zipios::DeflateOutputStreambuf::~DeflateOutputStreambuf(), zipios::ZipOutputStreambuf::closeEntry(), and finish().

◆ endDeflation()

void zipios::DeflateOutputStreambuf::endDeflation ( )

privateinherited

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

Definition at line 377 of file deflateoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::flushOutvec(), zipios::getBufferSize(), zipios::DeflateOutputStreambuf::m_outvec, zipios::DeflateOutputStreambuf::m_overflown_bytes, zipios::DeflateOutputStreambuf::m_zs, and zipios::DeflateOutputStreambuf::overflow().

Referenced by zipios::DeflateOutputStreambuf::closeStream().

◆ finish()

void zipios::GZIPOutputStreambuf::finish ( )

Write whatever is still necessary and close the streams.

Definition at line 102 of file gzipoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::closeStream(), m_open, and writeTrailer().

Referenced by ~GZIPOutputStreambuf(), and close().

◆ flushOutvec()

void zipios::DeflateOutputStreambuf::flushOutvec ( )

privateinherited

This function flushes m_outvec and updates the output pointer and size m_zs.next_out and m_zs.avail_out.

Todo:: We need to redesign the class to allow for STORED files to flow through without the need to have this crap of bytes to skip...

Definition at line 346 of file deflateoutputstreambuf.cpp.

References zipios::getBufferSize(), zipios::FilterOutputStreambuf::m_outbuf, zipios::DeflateOutputStreambuf::m_outvec, and zipios::DeflateOutputStreambuf::m_zs.

Referenced by zipios::DeflateOutputStreambuf::endDeflation(), and zipios::DeflateOutputStreambuf::overflow().

◆ getCrc32()

uint32_t zipios::DeflateOutputStreambuf::getCrc32 ( ) const

inherited

This function returns the CRC32 for the current file.

The returned value is the CRC for the data that has been compressed already (due to calls 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.

Returns: The CRC32 of the last file that was passed through.

Definition at line 234 of file deflateoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::m_crc32.

Referenced by zipios::ZipOutputStreambuf::updateEntryHeaderInfo(), and writeTrailer().

◆ getSize()

size_t zipios::DeflateOutputStreambuf::getSize ( ) const

inherited

This function returns the number of bytes written to the streambuf object and that were 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. In other words, the size of the uncompressed data.

Returns: The uncompressed size of the file that got written here.

Definition at line 251 of file deflateoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::m_overflown_bytes.

Referenced by zipios::ZipOutputStreambuf::updateEntryHeaderInfo(), and writeTrailer().

◆ init()

bool zipios::DeflateOutputStreambuf::init ( FileEntry::CompressionLevel compression_level )

inherited

This method is called in the constructor, so it must not write anything to the output streambuf m_outbuf (see notice in constructor.)

It will initialize the output stream as required to accept data to be compressed using the zlib library. The compression level is expected to come from the FileEntry which is about to be saved in the file.

Parameters

[in] compression_level The level of compression. A number from 1 to 100 or a special number representing the best, minimum, maximum compression available.

Returns: true if the initialization succeeded, false otherwise.

Definition at line 101 of file deflateoutputstreambuf.cpp.

References zipios::FileEntry::COMPRESSION_LEVEL_DEFAULT, zipios::FileEntry::COMPRESSION_LEVEL_FASTEST, zipios::FileEntry::COMPRESSION_LEVEL_MAXIMUM, zipios::FileEntry::COMPRESSION_LEVEL_MINIMUM, zipios::FileEntry::COMPRESSION_LEVEL_NONE, zipios::FileEntry::COMPRESSION_LEVEL_SMALLEST, zipios::getBufferSize(), zipios::DeflateOutputStreambuf::m_crc32, zipios::DeflateOutputStreambuf::m_invec, zipios::DeflateOutputStreambuf::m_outvec, zipios::DeflateOutputStreambuf::m_zs, and zipios::DeflateOutputStreambuf::m_zs_initialized.

Referenced by GZIPOutputStreambuf(), and zipios::ZipOutputStreambuf::putNextEntry().

◆ overflow()

int zipios::GZIPOutputStreambuf::overflow ( int c = EOF )

overrideprotectedvirtual

This function is called by the streambuf implementation whenever "too many bytes" are in the output buffer, ready to be compressed.

Exceptions

IOException This exception is raised whenever the overflow() function calls a zlib library function which returns an error.

Parameters

[in] c The character (byte) that overflowed the buffer.

Returns: Always zero (0).

Reimplemented from zipios::DeflateOutputStreambuf.

Definition at line 115 of file gzipoutputstreambuf.cpp.

References m_open, zipios::DeflateOutputStreambuf::overflow(), and writeHeader().

◆ setComment()

void zipios::GZIPOutputStreambuf::setComment ( std::string const & comment )

Definition at line 82 of file gzipoutputstreambuf.cpp.

References m_comment.

◆ setFilename()

void zipios::GZIPOutputStreambuf::setFilename ( std::string const & filename )

Definition at line 76 of file gzipoutputstreambuf.cpp.

References m_filename.

◆ sync()

int zipios::GZIPOutputStreambuf::sync ( )

overrideprotectedvirtual

The sync() function is expected to clear the input buffer so that any new data read from the input (i.e. a file) are re-read from disk. However, a call to sync() could break the filtering functionality so we do not implement it at all.

This means you are stuck with the existing buffer. But to make sure the system understands that, we always returns -1.

Reimplemented from zipios::DeflateOutputStreambuf.

Definition at line 127 of file gzipoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::sync().

◆ writeHeader()

void zipios::GZIPOutputStreambuf::writeHeader ( )

private

Todo:: We need to know of the last modification time instead of saving all zeros for MTIME values.

Todo:: : I am thinking that the OS should be 3 under Unices.

Definition at line 133 of file gzipoutputstreambuf.cpp.

References m_comment, m_filename, and zipios::FilterOutputStreambuf::m_outbuf.

Referenced by overflow().

◆ writeInt()

void zipios::GZIPOutputStreambuf::writeInt ( uint32_t i )

private

Todo:: : add support for 64 bit files if it exists?

Definition at line 183 of file gzipoutputstreambuf.cpp.

References zipios::FilterOutputStreambuf::m_outbuf.

Referenced by writeTrailer().

◆ writeTrailer()

void zipios::GZIPOutputStreambuf::writeTrailer ( )

private

Definition at line 175 of file gzipoutputstreambuf.cpp.

References zipios::DeflateOutputStreambuf::getCrc32(), zipios::DeflateOutputStreambuf::getSize(), and writeInt().

Referenced by finish().

Member Data Documentation

◆ m_comment

std::string zipios::GZIPOutputStreambuf::m_comment = std::string()

private

Definition at line 62 of file gzipoutputstreambuf.hpp.

Referenced by setComment(), and writeHeader().

◆ m_crc32

uint32_t zipios::DeflateOutputStreambuf::m_crc32 = 0

protectedinherited

Definition at line 67 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::getCrc32(), zipios::DeflateOutputStreambuf::init(), zipios::DeflateOutputStreambuf::overflow(), zipios::ZipOutputStreambuf::overflow(), and zipios::ZipOutputStreambuf::setEntryClosedState().

◆ m_filename

std::string zipios::GZIPOutputStreambuf::m_filename = std::string()

private

Definition at line 61 of file gzipoutputstreambuf.hpp.

Referenced by setFilename(), and writeHeader().

◆ m_invec

std::vector<char> zipios::DeflateOutputStreambuf::m_invec = std::vector<char>()

protectedinherited

Definition at line 66 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::init(), zipios::DeflateOutputStreambuf::overflow(), zipios::ZipOutputStreambuf::overflow(), and zipios::ZipOutputStreambuf::putNextEntry().

◆ m_open

bool zipios::GZIPOutputStreambuf::m_open = false

private

Definition at line 63 of file gzipoutputstreambuf.hpp.

Referenced by finish(), and overflow().

◆ m_outbuf

std::streambuf* zipios::FilterOutputStreambuf::m_outbuf = nullptr

protectedinherited

Definition at line 50 of file filteroutputstreambuf.hpp.

Referenced by zipios::FilterOutputStreambuf::FilterOutputStreambuf(), zipios::ZipOutputStreambuf::finish(), zipios::DeflateOutputStreambuf::flushOutvec(), zipios::ZipOutputStreambuf::overflow(), zipios::ZipOutputStreambuf::putNextEntry(), zipios::ZipOutputStreambuf::updateEntryHeaderInfo(), writeHeader(), and writeInt().

◆ m_outvec

std::vector<char> zipios::DeflateOutputStreambuf::m_outvec = std::vector<char>()

privateinherited

Definition at line 76 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::endDeflation(), zipios::DeflateOutputStreambuf::flushOutvec(), zipios::DeflateOutputStreambuf::init(), and zipios::DeflateOutputStreambuf::overflow().

◆ m_overflown_bytes

uint32_t zipios::DeflateOutputStreambuf::m_overflown_bytes = 0

protectedinherited

Definition at line 65 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::endDeflation(), zipios::DeflateOutputStreambuf::getSize(), zipios::ZipOutputStreambuf::overflow(), and zipios::ZipOutputStreambuf::putNextEntry().

◆ m_zs

z_stream zipios::DeflateOutputStreambuf::m_zs = z_stream()

privateinherited

Definition at line 73 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::closeStream(), zipios::DeflateOutputStreambuf::endDeflation(), zipios::DeflateOutputStreambuf::flushOutvec(), zipios::DeflateOutputStreambuf::init(), and zipios::DeflateOutputStreambuf::overflow().

◆ m_zs_initialized

bool zipios::DeflateOutputStreambuf::m_zs_initialized = false

privateinherited

Definition at line 74 of file deflateoutputstreambuf.hpp.

Referenced by zipios::DeflateOutputStreambuf::closeStream(), and zipios::DeflateOutputStreambuf::init().

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

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ GZIPOutputStreambuf()

◆ ~GZIPOutputStreambuf()

Member Function Documentation

◆ close()

◆ closeStream()

◆ endDeflation()

◆ finish()

◆ flushOutvec()

◆ getCrc32()

◆ getSize()

◆ init()

◆ overflow()

◆ setComment()

◆ setFilename()

◆ sync()

◆ writeHeader()

◆ writeInt()

◆ writeTrailer()

Member Data Documentation

◆ m_comment

◆ m_crc32

◆ m_filename

◆ m_invec

◆ m_open

◆ m_outbuf

◆ m_outvec

◆ m_overflown_bytes

◆ m_zs

◆ m_zs_initialized