OGRE  1.12.9
Object-Oriented Graphics Rendering Engine
Ogre::StreamSerialiser Class Reference

Utility class providing helper methods for reading / writing structured data held in a DataStream. More...

#include <OgreStreamSerialiser.h>

+ Inheritance diagram for Ogre::StreamSerialiser:

Classes

struct  Chunk
 Definition of a chunk of data in a file. More...
 

Public Types

enum  Endian { ENDIAN_AUTO, ENDIAN_BIG, ENDIAN_LITTLE }
 The endianness of files. More...
 
enum  RealStorageFormat { REAL_FLOAT, REAL_DOUBLE }
 The storage format of Real values. More...
 

Public Member Functions

 StreamSerialiser (const DataStreamPtr &stream, Endian endianMode=ENDIAN_AUTO, bool autoHeader=true, RealStorageFormat realFormat=REAL_FLOAT)
 Constructor. More...
 
virtual ~StreamSerialiser ()
 
virtual bool eof () const
 Reports whether the stream is at the end of file. More...
 
virtual const ChunkgetCurrentChunk () const
 Get the definition of the current chunk being read (if any). More...
 
size_t getCurrentChunkDepth () const
 Report the current depth of the chunk nesting, whether reading or writing. More...
 
uint32 getCurrentChunkID () const
 Get the ID of the chunk that's currently being read/written, if any. More...
 
virtual Endian getEndian () const
 Get the endian mode. More...
 
size_t getOffsetFromChunkStart () const
 Get the current byte position relative to the start of the data section of the last chunk that was read or written. More...
 
virtual bool isEndOfChunk (uint32 id)
 Return whether the current data pointer is at the end of the current chunk. More...
 
virtual uint32 peekNextChunkID ()
 Call this to 'peek' at the next chunk ID without permanently moving the stream pointer. More...
 
virtual void read (AxisAlignedBox *aabb, size_t count=1)
 
virtual void read (bool *val, size_t count=1)
 
virtual void read (Matrix3 *m, size_t count=1)
 
virtual void read (Matrix4 *m, size_t count=1)
 
virtual void read (Node *node, size_t count=1)
 
virtual void read (Plane *plane, size_t count=1)
 
virtual void read (Quaternion *q, size_t count=1)
 
virtual void read (Radian *angle, size_t count=1)
 
virtual void read (Ray *ray, size_t count=1)
 
virtual void read (Real *val, size_t count=1)
 
virtual void read (Sphere *sphere, size_t count=1)
 
virtual void read (String *string)
 
template<typename T >
void read (T *pT, size_t count=1)
 Catch-all method to read primitive types. More...
 
virtual void read (Vector2 *vec, size_t count=1)
 read a Vector3 More...
 
virtual void read (Vector3 *vec, size_t count=1)
 
virtual void read (Vector4 *vec, size_t count=1)
 
virtual const ChunkreadChunkBegin ()
 Reads the start of the next chunk in the file. More...
 
virtual const ChunkreadChunkBegin (uint32 id, uint16 maxVersion, const String &msg=BLANKSTRING)
 Reads the start of the next chunk so long as it's of a given ID and version. More...
 
virtual void readChunkEnd (uint32 id)
 Finish the reading of a chunk. More...
 
virtual void readData (void *buf, size_t size, size_t count)
 Read arbitrary data from a stream. More...
 
virtual void startDeflate (size_t avail_in=0)
 Start (un)compressing data. More...
 
virtual void stopDeflate ()
 Stop (un)compressing data. More...
 
virtual void undoReadChunk (uint32 id)
 Call this to 'rewind' the stream to just before the start of the current chunk. More...
 
virtual void write (const AxisAlignedBox *aabb, size_t count=1)
 
virtual void write (const bool *boolean, size_t count=1)
 
virtual void write (const Matrix3 *m, size_t count=1)
 
virtual void write (const Matrix4 *m, size_t count=1)
 
virtual void write (const Node *node, size_t count=1)
 
virtual void write (const Plane *plane, size_t count=1)
 
virtual void write (const Quaternion *q, size_t count=1)
 
virtual void write (const Radian *angle, size_t count=1)
 
virtual void write (const Ray *ray, size_t count=1)
 
virtual void write (const Real *val, size_t count=1)
 
virtual void write (const Sphere *sphere, size_t count=1)
 
virtual void write (const String *string)
 
template<typename T >
void write (const T *pT, size_t count=1)
 Catch-all method to write primitive types. More...
 
virtual void write (const Vector2 *vec, size_t count=1)
 
virtual void write (const Vector3 *vec, size_t count=1)
 
virtual void write (const Vector4 *vec, size_t count=1)
 
virtual void writeChunkBegin (uint32 id, uint16 version=1)
 Begin writing a new chunk. More...
 
virtual void writeChunkEnd (uint32 id)
 End writing a chunk. More...
 
virtual void writeData (const void *buf, size_t size, size_t count)
 Write arbitrary data to a stream. More...
 

Static Public Member Functions

static uint32 makeIdentifier (const char(&code)[5])
 Pack a 4-character code into a 32-bit identifier. More...
 

Detailed Description

Utility class providing helper methods for reading / writing structured data held in a DataStream.

Remarks
The structure of a file read / written by this class is a series of 'chunks'. A chunk-based format has the advantage of being extensible later, and it's robust, in that a reader can skip chunks that they are not able (or willing) to process.
Chunks are contained serially in the file, but they can also be nested in order both to provide context, and to group chunks together for potential skipping.
The data format of a chunk is as follows:
  1. Chunk ID (32-bit uint). This can be any number unique in a context, except the numbers 0x0000, 0x0001 and 0x1000, which are reserved for Ogre's use
  2. Chunk version (16-bit uint). Chunks can change over time so this version number reflects that
  3. Length (32-bit uint). The length of the chunk data section, including nested chunks. Note that this length excludes this header, but includes the header of any nested chunks.
  4. Checksum (32-bit uint). Checksum value generated from the above - basically lets us check this is a valid chunk.
  5. Chunk data The 'Chunk data' section will contain chunk-specific data, which may include other nested chunks.

Member Enumeration Documentation

◆ Endian

The endianness of files.

Enumerator
ENDIAN_AUTO 

Automatically determine endianness.

ENDIAN_BIG 

Use big endian (0x1000 is serialised as 0x10 0x00)

ENDIAN_LITTLE 

Use little endian (0x1000 is serialised as 0x00 0x10)

◆ RealStorageFormat

The storage format of Real values.

Enumerator
REAL_FLOAT 

Real is stored as float, reducing precision if you're using OGRE_DOUBLE_PRECISION.

REAL_DOUBLE 

Real as stored as double, not useful unless you're using OGRE_DOUBLE_PRECISION.

Constructor & Destructor Documentation

◆ StreamSerialiser()

Ogre::StreamSerialiser::StreamSerialiser ( const DataStreamPtr stream,
Endian  endianMode = ENDIAN_AUTO,
bool  autoHeader = true,
RealStorageFormat  realFormat = REAL_FLOAT 
)

Constructor.

Parameters
streamThe stream on which you will read / write data.
endianModeThe endian mode in which to read / writedata. If left at the default, when writing the endian mode will be the native platform mode, and when reading it's expected that the first chunk encountered will be the header chunk, which will determine the endian mode.
autoHeaderIf true, the first write or read to this stream will automatically read / write the header too. This is required if you set endianMode to ENDIAN_AUTO, but if you manually set the endian mode, then you can skip writing / reading the header if you wish, if for example this stream is midway through a file which has already included header information.
realFormatSet the format you want to write reals in. Only useful for files that you're writing (since when reading this is picked up from the file), and can only be changed if autoHeader is true, since real format is stored in the header. Defaults to float unless you're using OGRE_DOUBLE_PRECISION.

◆ ~StreamSerialiser()

virtual Ogre::StreamSerialiser::~StreamSerialiser ( )
virtual

Member Function Documentation

◆ getEndian()

virtual Endian Ogre::StreamSerialiser::getEndian ( ) const
inlinevirtual

Get the endian mode.

Remarks
If the result is ENDIAN_AUTO, this mode will change when the first piece of data is read / written.

◆ makeIdentifier()

static uint32 Ogre::StreamSerialiser::makeIdentifier ( const char(&)  code[5])
static

Pack a 4-character code into a 32-bit identifier.

Remarks
You can use this to generate id's for your chunks based on friendlier 4-character codes rather than assigning numerical IDs, if you like.
Parameters
codeString to pack - must be 4 characters and '\0'

◆ getCurrentChunkDepth()

size_t Ogre::StreamSerialiser::getCurrentChunkDepth ( ) const
inline

Report the current depth of the chunk nesting, whether reading or writing.

Remarks
Returns how many levels of nested chunks are currently being processed, either writing or reading. In order to tidily finish, you must call read/writeChunkEnd this many times.

◆ getCurrentChunkID()

uint32 Ogre::StreamSerialiser::getCurrentChunkID ( ) const

Get the ID of the chunk that's currently being read/written, if any.

Returns
The id of the current chunk being read / written (at the tightest level of nesting), or zero if no chunk is being processed.

◆ getOffsetFromChunkStart()

size_t Ogre::StreamSerialiser::getOffsetFromChunkStart ( ) const

Get the current byte position relative to the start of the data section of the last chunk that was read or written.

Returns
the offset. Note that a return value of 0 means that either the position is at the start of the chunk data section (ie right after the header), or that no chunk is currently active. Use getCurrentChunkID or getCurrentChunkDepth to determine if a chunk is active.

◆ readChunkBegin() [1/2]

virtual const Chunk* Ogre::StreamSerialiser::readChunkBegin ( )
virtual

Reads the start of the next chunk in the file.

Remarks
Files are serialised in a chunk-based manner, meaning that each section of data is prepended by a chunk header. After reading this chunk header, the next set of data is available directly afterwards.
Note
When you have finished with this chunk, you should call readChunkEnd. This will perform a bit of validation and clear the chunk from the stack.
Returns
The Chunk that comes next

◆ readChunkBegin() [2/2]

virtual const Chunk* Ogre::StreamSerialiser::readChunkBegin ( uint32  id,
uint16  maxVersion,
const String msg = BLANKSTRING 
)
virtual

Reads the start of the next chunk so long as it's of a given ID and version.

Remarks
This method operates like readChunkBegin, except it checks the ID and version.
Parameters
idThe ID you're expecting. If the next chunk isn't of this ID, then the chunk read is undone and the method returns null.
maxVersionThe maximum version you're able to process. If the ID is correct but the version exceeds what is passed in here, the chunk is skipped over, the problem logged and null is returned.
msgDescriptive text added to the log if versions are not compatible
Returns
The chunk if it passes the validation.

◆ undoReadChunk()

virtual void Ogre::StreamSerialiser::undoReadChunk ( uint32  id)
virtual

Call this to 'rewind' the stream to just before the start of the current chunk.

Remarks
The most common case of wanting to use this is if you'd calledReadChunkBegin(), but the chunk you read wasn't one you wanted to process, and rather than skipping over it (which readChunkEnd() would do), you want to backtrack and give something else an opportunity to read it.
Parameters
idThe id of the chunk that you were reading (for validation purposes)

◆ peekNextChunkID()

virtual uint32 Ogre::StreamSerialiser::peekNextChunkID ( )
virtual

Call this to 'peek' at the next chunk ID without permanently moving the stream pointer.

◆ readChunkEnd()

virtual void Ogre::StreamSerialiser::readChunkEnd ( uint32  id)
virtual

Finish the reading of a chunk.

Remarks
You can call this method at any point after calling readChunkBegin, even if you didn't read all the rest of the data in the chunk. If you did not read to the end of a chunk, this method will automatically skip over the remainder of the chunk and position the stream just after it.
Parameters
idThe id of the chunk that you were reading (for validation purposes)

◆ isEndOfChunk()

virtual bool Ogre::StreamSerialiser::isEndOfChunk ( uint32  id)
virtual

Return whether the current data pointer is at the end of the current chunk.

Parameters
idThe id of the chunk that you were reading (for validation purposes)

◆ eof()

virtual bool Ogre::StreamSerialiser::eof ( ) const
virtual

Reports whether the stream is at the end of file.

◆ getCurrentChunk()

virtual const Chunk* Ogre::StreamSerialiser::getCurrentChunk ( ) const
virtual

Get the definition of the current chunk being read (if any).

◆ writeChunkBegin()

virtual void Ogre::StreamSerialiser::writeChunkBegin ( uint32  id,
uint16  version = 1 
)
virtual

Begin writing a new chunk.

Remarks
This starts the process of writing a new chunk to the stream. This will write the chunk header for you, and store a pointer so that the class can automatically go back and fill in the size for you later should you need it to. If you have already begun a chunk without ending it, then this method will start a nested chunk within it. Once written, you can then start writing chunk-specific data into your stream.
Note
If this is the first chunk in the file
Parameters
idThe identifier of the new chunk. Any value that's unique in the file context is valid, except for the numbers 0x0001 and 0x1000 which are reserved for internal header identification use.
versionThe version of the chunk you're writing

◆ writeChunkEnd()

virtual void Ogre::StreamSerialiser::writeChunkEnd ( uint32  id)
virtual

End writing a chunk.

Parameters
idThe identifier of the chunk - this is really just a safety check, since you can only end the chunk you most recently started.

◆ writeData()

virtual void Ogre::StreamSerialiser::writeData ( const void *  buf,
size_t  size,
size_t  count 
)
virtual

Write arbitrary data to a stream.

Parameters
bufPointer to bytes
sizeThe size of each element to write; each will be endian-flipped if necessary
countThe number of elements to write

◆ write() [1/16]

template<typename T >
void Ogre::StreamSerialiser::write ( const T *  pT,
size_t  count = 1 
)
inline

Catch-all method to write primitive types.

◆ write() [2/16]

virtual void Ogre::StreamSerialiser::write ( const Real val,
size_t  count = 1 
)
virtual

◆ write() [3/16]

virtual void Ogre::StreamSerialiser::write ( const Vector2 vec,
size_t  count = 1 
)
virtual

◆ write() [4/16]

virtual void Ogre::StreamSerialiser::write ( const Vector3 vec,
size_t  count = 1 
)
virtual

◆ write() [5/16]

virtual void Ogre::StreamSerialiser::write ( const Vector4 vec,
size_t  count = 1 
)
virtual

◆ write() [6/16]

virtual void Ogre::StreamSerialiser::write ( const Quaternion q,
size_t  count = 1 
)
virtual

◆ write() [7/16]

virtual void Ogre::StreamSerialiser::write ( const Matrix3 m,
size_t  count = 1 
)
virtual

◆ write() [8/16]

virtual void Ogre::StreamSerialiser::write ( const Matrix4 m,
size_t  count = 1 
)
virtual

◆ write() [9/16]

virtual void Ogre::StreamSerialiser::write ( const String string)
virtual

◆ write() [10/16]

virtual void Ogre::StreamSerialiser::write ( const AxisAlignedBox aabb,
size_t  count = 1 
)
virtual

◆ write() [11/16]

virtual void Ogre::StreamSerialiser::write ( const Sphere sphere,
size_t  count = 1 
)
virtual

◆ write() [12/16]

virtual void Ogre::StreamSerialiser::write ( const Plane plane,
size_t  count = 1 
)
virtual

◆ write() [13/16]

virtual void Ogre::StreamSerialiser::write ( const Ray ray,
size_t  count = 1 
)
virtual

◆ write() [14/16]

virtual void Ogre::StreamSerialiser::write ( const Radian angle,
size_t  count = 1 
)
virtual

◆ write() [15/16]

virtual void Ogre::StreamSerialiser::write ( const Node node,
size_t  count = 1 
)
virtual

◆ write() [16/16]

virtual void Ogre::StreamSerialiser::write ( const bool *  boolean,
size_t  count = 1 
)
virtual

◆ readData()

virtual void Ogre::StreamSerialiser::readData ( void *  buf,
size_t  size,
size_t  count 
)
virtual

Read arbitrary data from a stream.

Parameters
bufPointer to bytes
sizeThe size of each element to read; each will be endian-flipped if necessary
countThe number of elements to read

◆ read() [1/16]

template<typename T >
void Ogre::StreamSerialiser::read ( T *  pT,
size_t  count = 1 
)
inline

Catch-all method to read primitive types.

◆ read() [2/16]

virtual void Ogre::StreamSerialiser::read ( Real val,
size_t  count = 1 
)
virtual

◆ read() [3/16]

virtual void Ogre::StreamSerialiser::read ( Vector2 vec,
size_t  count = 1 
)
virtual

read a Vector3

◆ read() [4/16]

virtual void Ogre::StreamSerialiser::read ( Vector3 vec,
size_t  count = 1 
)
virtual

◆ read() [5/16]

virtual void Ogre::StreamSerialiser::read ( Vector4 vec,
size_t  count = 1 
)
virtual

◆ read() [6/16]

virtual void Ogre::StreamSerialiser::read ( Quaternion q,
size_t  count = 1 
)
virtual

◆ read() [7/16]

virtual void Ogre::StreamSerialiser::read ( Matrix3 m,
size_t  count = 1 
)
virtual

◆ read() [8/16]

virtual void Ogre::StreamSerialiser::read ( Matrix4 m,
size_t  count = 1 
)
virtual

◆ read() [9/16]

virtual void Ogre::StreamSerialiser::read ( String string)
virtual

◆ read() [10/16]

virtual void Ogre::StreamSerialiser::read ( AxisAlignedBox aabb,
size_t  count = 1 
)
virtual

◆ read() [11/16]

virtual void Ogre::StreamSerialiser::read ( Sphere sphere,
size_t  count = 1 
)
virtual

◆ read() [12/16]

virtual void Ogre::StreamSerialiser::read ( Plane plane,
size_t  count = 1 
)
virtual

◆ read() [13/16]

virtual void Ogre::StreamSerialiser::read ( Ray ray,
size_t  count = 1 
)
virtual

◆ read() [14/16]

virtual void Ogre::StreamSerialiser::read ( Radian angle,
size_t  count = 1 
)
virtual

◆ read() [15/16]

virtual void Ogre::StreamSerialiser::read ( Node node,
size_t  count = 1 
)
virtual

◆ read() [16/16]

virtual void Ogre::StreamSerialiser::read ( bool *  val,
size_t  count = 1 
)
virtual

◆ startDeflate()

virtual void Ogre::StreamSerialiser::startDeflate ( size_t  avail_in = 0)
virtual

Start (un)compressing data.

Parameters
avail_inAvailable bytes for uncompressing

◆ stopDeflate()

virtual void Ogre::StreamSerialiser::stopDeflate ( )
virtual

Stop (un)compressing data.


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