OGRE-Next  4.0.0unstable
Object-Oriented Graphics Rendering Engine
Ogre::DeflateStream Class Referencefinal

Stream which compresses / uncompresses data using the 'deflate' compression algorithm. More...

#include <OgreDeflate.h>

+ Inheritance diagram for Ogre::DeflateStream:

Public Types

enum  StreamType { Invalid = -1 , Deflate = 0 , ZLib = 1 , GZip = 2 }
 Requested stream type. More...
 
- Public Types inherited from Ogre::DataStream
enum  AccessMode { READ = 1 , WRITE = 2 }
 

Public Member Functions

 DeflateStream (const DataStreamPtr &compressedStream, const String &tmpFileName="", size_t avail_in=0)
 Constructor for creating unnamed stream wrapping another stream. More...
 
 DeflateStream (const String &name, const DataStreamPtr &compressedStream, const String &tmpFileName="", size_t avail_in=0)
 Constructor for creating named stream wrapping another stream. More...
 
 DeflateStream (const String &name, const DataStreamPtr &compressedStream, StreamType streamType, const String &tmpFileName="", size_t avail_in=0)
 Constructor for creating named stream wrapping another stream. More...
 
 ~DeflateStream () override
 
void close () override
 Close the stream; this makes further operations invalid. More...
 
bool eof () const override
 Returns true if the stream has reached the end. More...
 
bool isCompressedStreamValid () const
 Returns whether the compressed stream is valid deflated data. More...
 
size_t read (void *buf, size_t count) override
 Read the requisite number of bytes from the stream, stopping at the end of the file. More...
 
void seek (size_t pos) override
 Repositions the read point to a specified byte. More...
 
void skip (long count) override
 Skip a defined number of bytes. More...
 
size_t tell () const override
 Returns the current byte offset from beginning. More...
 
size_t write (const void *buf, size_t count) override
 Write the requisite number of bytes from the stream (only applicable to streams that are not read-only) More...
 
- Public Member Functions inherited from Ogre::DataStream
 DataStream (const String &name, uint16 accessMode=READ)
 Constructor for creating named streams. More...
 
 DataStream (uint16 accessMode=READ)
 Constructor for creating unnamed streams. More...
 
virtual ~DataStream ()
 
uint16 getAccessMode () const
 Gets the access mode of the stream. More...
 
virtual String getAsString ()
 Returns a String containing the entire stream. More...
 
virtual String getLine (bool trimAfter=true)
 Returns a String containing the next line of data, optionally trimmed for whitespace. More...
 
const StringgetName ()
 Returns the name of the stream, if it has one. More...
 
virtual bool isReadable () const
 Reports whether this stream is readable. More...
 
virtual bool isWriteable () const
 Reports whether this stream is writeable. More...
 
template<typename T >
DataStreamoperator>> (T &val)
 
virtual size_t readLine (char *buf, size_t maxCount, const String &delim="\n")
 Get a single line from the stream. More...
 
size_t size () const
 Returns the total size of the data to be read from the stream, or 0 if this is indeterminate for this stream. More...
 
virtual size_t skipLine (const String &delim="\n")
 Skip a single line from the stream. More...
 

Detailed Description

Stream which compresses / uncompresses data using the 'deflate' compression algorithm.

Remarks
This stream is designed to wrap another stream for the actual source / destination of the compressed data, it has no concrete source / data itself. The idea is that you pass uncompressed data through this stream, and the underlying stream reads/writes compressed data to the final source.
Note
This is an alternative to using a compressed archive since it is able to compress & decompress regardless of the actual source of the stream. You should avoid using this with already compressed archives. Also note that this cannot be used as a read / write stream, only a read-only or write-only stream.

Member Enumeration Documentation

◆ StreamType

Requested stream type.

All are essentially the same deflate stream with varying wrapping. ZLib is used by default.

Enumerator
Invalid 

Unexpected stream type or uncompressed data.

Deflate 

no header, no checksum, rfc1951

ZLib 

2 byte header, 4 byte footer with adler32 checksum, rfc1950

GZip 

10 byte header, 8 byte footer with crc32 checksum and unpacked size, rfc1952

Constructor & Destructor Documentation

◆ DeflateStream() [1/3]

Ogre::DeflateStream::DeflateStream ( const DataStreamPtr compressedStream,
const String tmpFileName = "",
size_t  avail_in = 0 
)

Constructor for creating unnamed stream wrapping another stream.

Parameters
compressedStreamThe stream that this stream will use when reading / writing compressed data. The access mode from this stream will be matched.
tmpFileNamePath/Filename to be used for temporary storage of incoming data
avail_inAvailable data length to be uncompressed. With it we can uncompress DataStream partly.

◆ DeflateStream() [2/3]

Ogre::DeflateStream::DeflateStream ( const String name,
const DataStreamPtr compressedStream,
const String tmpFileName = "",
size_t  avail_in = 0 
)

Constructor for creating named stream wrapping another stream.

Parameters
nameThe name to give this stream
compressedStreamThe stream that this stream will use when reading / writing compressed data. The access mode from this stream will be matched.
tmpFileNamePath/Filename to be used for temporary storage of incoming data
avail_inAvailable data length to be uncompressed. With it we can uncompress DataStream partly.

◆ DeflateStream() [3/3]

Ogre::DeflateStream::DeflateStream ( const String name,
const DataStreamPtr compressedStream,
StreamType  streamType,
const String tmpFileName = "",
size_t  avail_in = 0 
)

Constructor for creating named stream wrapping another stream.

Parameters
nameThe name to give this stream
compressedStreamThe stream that this stream will use when reading / writing compressed data. The access mode from this stream will be matched.
streamTypeThe type of compressed stream
tmpFileNamePath/Filename to be used for temporary storage of incoming data
avail_inAvailable data length to be uncompressed. With it we can uncompress DataStream partly.

◆ ~DeflateStream()

Ogre::DeflateStream::~DeflateStream ( )
override

Member Function Documentation

◆ close()

void Ogre::DeflateStream::close ( )
overridevirtual

Close the stream; this makes further operations invalid.

Implements Ogre::DataStream.

◆ eof()

bool Ogre::DeflateStream::eof ( ) const
overridevirtual

Returns true if the stream has reached the end.

Implements Ogre::DataStream.

◆ isCompressedStreamValid()

bool Ogre::DeflateStream::isCompressedStreamValid ( ) const
inline

Returns whether the compressed stream is valid deflated data.

Remarks
If you pass this class a READ stream which is not compressed with the deflate algorithm, this method returns false and all read commands will actually be executed as passthroughs as a fallback.

◆ read()

size_t Ogre::DeflateStream::read ( void *  buf,
size_t  count 
)
overridevirtual

Read the requisite number of bytes from the stream, stopping at the end of the file.

Parameters
bufReference to a buffer pointer
countNumber of bytes to read
Returns
The number of bytes read

Implements Ogre::DataStream.

◆ seek()

void Ogre::DeflateStream::seek ( size_t  pos)
overridevirtual

Repositions the read point to a specified byte.

Implements Ogre::DataStream.

◆ skip()

void Ogre::DeflateStream::skip ( long  count)
overridevirtual

Skip a defined number of bytes.

This can also be a negative value, in which case the file pointer rewinds a defined number of bytes.

Implements Ogre::DataStream.

◆ tell()

size_t Ogre::DeflateStream::tell ( ) const
overridevirtual

Returns the current byte offset from beginning.

Implements Ogre::DataStream.

◆ write()

size_t Ogre::DeflateStream::write ( const void *  buf,
size_t  count 
)
overridevirtual

Write the requisite number of bytes from the stream (only applicable to streams that are not read-only)

Parameters
bufPointer to a buffer containing the bytes to write
countNumber of bytes to write
Returns
The number of bytes written

Reimplemented from Ogre::DataStream.


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