RWCompressedIOStream< Compressor > Class Template Reference
[Virtual Streams]

Compresses and serializes data to or deserializes and decompresses data from an associated std::streambuf. More...

#include <rw/tools/cmpstream.h>

List of all members.

Public Member Functions
	RWCompressedIOStream (std::streambuf *stream_buffer, std::ios_base::openmode mode=std::ios_base::in|std::ios_base::out, rwuint32 block_size=2048U, const Compressor &compressor=Compressor())
	RWCompressedIOStream (std::iostream &stream, std::ios_base::openmode mode=std::ios_base::in|std::ios_base::out, rwuint32 block_size=2048U, const Compressor &compressor=Compressor())
void	open (std::streambuf *stream_buffer, std::ios_base::openmode mode=std::ios_base::in|std::ios_base::out, rwuint32 block_size=2048U)
void	close ()
bool	is_open () const
const Compressor &	get_compressor () const
RWCompressedStreamBuffer < Compressor > *	rdbuf () const

---

Detailed Description

template<class Compressor>
class RWCompressedIOStream< Compressor >

Class RWCompressedIOStream compresses and serializes data to or deserializes and decompresses data from an associated std::streambuf. Data read from the associated streambuf must have been serialized with RWCompressedOStream or RWCompressedIOStream, and any data written to the associated streambuf can be deserialized with RWCompressedIStream or RWCompressedIOStream.

See also:

RWCompressedStreamBuffer

Note:

RWCompressedIOStream can be interrogated as to the stream state using member functions good(), bad(), eof(), etc.

Synopsis

 #include <rw/tools/cmpstream.h>

 std::fstream f("output.fil");
 RWCompressedIOStream<Compressor> cstr(f);   // Construct an RWCompressedIOStream using f's streambuf

Persistence

None

Examples

 // for SourcePro Core Tools Module compressed streams
 #include <rw/tools/cmpstream.h>

 // for SourcePro Core Tools Module endian streams
 #include <rw/estream.h>

 // for SourcePro Core Tools Module strings
 #include <rw/cstring.h>

 // for SourcePro Core Snappy compressor
 #include <rw/tools/snappy/RWSnappyCompressor.h>

 // for C++ Standard Library file streams
 #include <fstream>

 int main ()
 {
   // open the file to write to and read from
   std::fstream data_file ("output.snap", std::ios_base::binary);

   // layer a compressed stream on top of the file
   RWCompressedIOStream<RWSnappyCompressor> compressed_stream (data_file);

   {
     // layer an endian stream on top of the compressed stream
     RWeostream endian_stream (compressed_stream);

     //
     // Any data written to the endian stream is converted into
     // an endian safe format by the endian stream, compressed by the
     // compressed stream, and written to the file by the file stream.
     //

     RWCString data ('a', 32);

     endian_stream << data;
   }

   // Ensure data written to the associated stream buffer is written to
   // the underlying stream buffer.
   compressed_stream.flush();

   {
     // layer an endian stream on top of the compressed stream
     RWeistream endian_stream (compressed_stream);

     //
     // Any data read from the endian stream is read from the file
     // stream, decompressed by the compressed stream, and converted into
     // an endian safe format into binary data by the endian stream.
     //

     RWCString data;

     compressed_stream >> data;

     std::cout << data;
   }

   return 0;
 }

Program output:

 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

---

Constructor & Destructor Documentation

template<class Compressor>

RWCompressedIOStream< Compressor >::RWCompressedIOStream	(	std::streambuf *	stream_buffer,
		std::ios_base::openmode	mode = std::ios_base::in | std::ios_base::out,
		rwuint32	block_size = 2048U,
		const Compressor &	compressor = Compressor()
	)			[inline]

Constructor initializes and opens the underlying stream buffer with the provided stream_buffer, mode, block_size, and compressor. If the open fails, failbit is set on this stream.

Note:

The mode is always combined with the appropriate flags to allow the underlying stream buffer to be used for input and output.

See also:

RWCompressedStreamBuffer::open()

template<class Compressor>

RWCompressedIOStream< Compressor >::RWCompressedIOStream	(	std::iostream &	stream,
		std::ios_base::openmode	mode = std::ios_base::in | std::ios_base::out,
		rwuint32	block_size = 2048U,
		const Compressor &	compressor = Compressor()
	)			[inline]

Constructor initializes and opens the underlying stream buffer with the provided mode, block_size, compressor, and the stream buffer associated with stream. If the open fails, failbit is set on this stream.

Note:

The mode is always combined with the appropriate flags to allow the underlying stream buffer to be used for input and output.

See also:

RWCompressedStreamBuffer::open()

---

Member Function Documentation

template<class Compressor>

void RWCompressedIOStream< Compressor >::close

(

)

[inline]

Closes the underlying stream buffer. If the close fails, failbit is set on this stream. After this method has been called, this stream cannot be used for input or output until a successfull call to open() has been made.

template<class Compressor>

const Compressor& RWCompressedIOStream< Compressor >::get_compressor

(

)

const [inline]

Returns a reference to the underlying stream buffer's compressor.

template<class Compressor>

bool RWCompressedIOStream< Compressor >::is_open

(

)

const [inline]

Returns true if the underlying stream buffer is open and is ready for use, otherwise returns false.

template<class Compressor>

void RWCompressedIOStream< Compressor >::open	(	std::streambuf *	stream_buffer,
		std::ios_base::openmode	mode = std::ios_base::in | std::ios_base::out,
		rwuint32	block_size = 2048U
	)			[inline]

Opens the underlying stream buffer with the provided stream_buffer, mode, and block_size. If the open fails, failbit is set on this stream.

Note:

The mode is always combined with the appropriate flags to allow the underlying stream buffer to be used for input and output.

See also:

RWCompressedStreamBuffer::open()

template<class Compressor>

RWCompressedStreamBuffer<Compressor>* RWCompressedIOStream< Compressor >::rdbuf

(

)

const [inline]

Returns a pointer to the underlying stream buffer.