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// =================================================================================================
// Copyright Adobe
// Copyright 2010 Adobe
// All Rights Reserved
//
// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it.
// =================================================================================================
#ifndef _IChunkBehavior_h_
#define _IChunkBehavior_h_
#include "public/include/XMP_Environment.h" // ! This must be the first include.
#include "public/include/XMP_Const.h"
#include "public/include/XMP_IO.hpp"
#include <vector>
namespace IFF_RIFF
{
/**
The IChunkBehavior is an interface that provides access to algorithm
for the read and write process of IFF/RIFF formated streams.
A file format specific instance based on this interface gets injected into
the class ChunkController and offers format specific algorithm wherever
the processing of a certain file format differs from the general specification
of RIFF/IFF.
That is e.g. the RF64 format where it is possible that the size value of the
top level chunk doesn't represent the real size. Or AVI, where are special rules
if the size of a chunk exceed the 4GB border.
*/
class IChunkContainer;
class Chunk;
struct ChunkIdentifier;
class ChunkPath;
class IChunkBehavior
{
public:
IChunkBehavior() : mMovablePaths(NULL) {}
virtual ~IChunkBehavior() {};
/**
* Set list of chunk paths of chunks that might be moved within the hierarchy
*/
inline void setMovablePaths( std::vector<ChunkPath>* paths ) { mMovablePaths = paths; }
/**
Validate the passed in size value, identify the valid size if the passed in isn't valid
and return the valid size.
throw an exception if the passed in size isn't valid and there's no way to identify a
valid size.
@param size Size value
@param id Identifier of chunk
@param tree Chunk tree
@param stream Stream handle
@return Valid size value.
*/
virtual XMP_Uns64 getRealSize( const XMP_Uns64 size, const ChunkIdentifier& id, IChunkContainer& tree, XMP_IO* stream ) = 0;
/**
Return the maximum size of a single chunk, i.e. the maximum size of a top-level chunk.
@return Maximum size
*/
virtual XMP_Uns64 getMaxChunkSize() const = 0;
/**
Return true if the passed identifier is valid for top-level chunks of a certain format.
@param id Chunk identifier
@param chunkNo order number of top-level chunk
@return true, if passed id is a valid top-level chunk
*/
virtual bool isValidTopLevelChunk( const ChunkIdentifier& id, XMP_Uns32 chunkNo ) = 0;
/**
Fix the hierarchy of chunks depending ones based on size changes of one or more chunks
and second based on format specific rules.
Throw an exception if the hierarchy can't be fixed.
@param tree Vector of root chunks.
*/
virtual void fixHierarchy( IChunkContainer& tree ) = 0;
/**
Insert a new chunk into the hierarchy of chunks. The behavior needs to decide the position
of the new chunk and has to do the insertion.
@param tree Chunk tree
@param chunk New chunk
*/
virtual void insertChunk( IChunkContainer& tree, Chunk& chunk ) = 0;
/**
Remove the chunk described by the passed ChunkPath.
@param tree Chunk tree
@param path Path to the chunk that needs to be removed
@return true if the chunk was removed and need to be deleted
*/
virtual bool removeChunk( IChunkContainer& tree, Chunk& chunk ) = 0;
protected:
/**
Create a FREE chunk.
If the chunkSize is smaller than the header+type - size then create an annotation chunk.
If the passed size is odd, then add a pad byte.
@param chunkSize Total size including header
@return New FREE chunk
*/
virtual Chunk* createFREE( XMP_Uns64 chunkSize ) = 0;
/**
Check if the passed chunk is a FREE chunk.
(Could be also a small annotation chunk with zero bytes in its data)
@param chunk A chunk
@return true if the passed chunk is a FREE chunk
*/
virtual XMP_Bool isFREEChunk( const Chunk& chunk ) const = 0;
/**
Return the minimum size of a FREE chunk
*/
virtual XMP_Uns64 getMinFREESize( ) const
= 0;
protected:
/************************************************************************/
/* END of Interface. The following are helper functions for all derived */
/* Behavior Classes */
/************************************************************************/
/**
Find a FREE chunk with the passed total size (including header). If the FREE chunk is found then
take care of the fact that is has to be that large (or larger) then the minimum size of a FREE chunk.
The method takes also into account that the passed size probably not includes a pad byte
@param tree Parent tree
@param requiredSize Required total size (including header)
@return Index of found FREE chunk
*/
XMP_Int32 findFREEChunk( const IChunkContainer& tree, XMP_Uns64 requiredSize );
/**
May we move a chunk of passed id/type
@param identifier id and type of chunk
@return true if such a chunk might be moved within the tree
*/
bool isMovable( const Chunk& chunk ) const;
/**
Validate recursively the offset values of all chunks.
Throws an exception if there is any discrepancy with the calculated offset.
@param tree (Sub-)tree of chunks
@param startOffset First offset in the (sub-)tree
*/
void validateOffsets( IChunkContainer& tree, XMP_Uns64 startOffset = 0 );
/**
Retrieve the free space at the passed position in the child list of the parent tree.
If there's a FREE chunk then return it.
@param outFreeBytes On return it takes the number of free bytes
@param tree Parent tree
@param index Position in the child list of the parent tree
@return FREE chunk if available
*/
Chunk* getFreeSpace( XMP_Int64& outFreeBytes, const IChunkContainer& tree, XMP_Uns32 index ) const ;
/**
Try to arrange all chunks of the source tree at their current location.
The method looks for FREE chunk around or for size changes of the chunks around and try that space.
If a chunk can't be arrange at its location it is moved to the end of the destination tree.
@param srcTree Tree that consists of the chunks that needs to be arranged
@param destTree Tree where chunks are added to if they can't be arranged
@return Index of last proceeded chunk
*/
void arrangeChunksInPlace( IChunkContainer& srcTree, IChunkContainer& destTree );
/**
This method proceeds the list of Chunks of the source tree in the passed range and looks for FREE chunks
in the destination tree to move the source chunks to.
Source tree and destination tree could be one and the same but it's not required. If both trees are the
same then it's not allowed to cross source and destination ranges.
@param srcTree Tree that consists of the chunks that needs to be arranged
@param destTree Tree where the method looks for FREE chunks
@param srcStart Start index within the source tree
@param srcEnd End index within the source tree (if booth, srcStart and srcEnd are zero then the complete list
of the source tree is proceeded)
@param destStart Start index within the destination tree
@param destEnd End index within the destination tree (if booth, destStart and destEnd are zero then the complete list
of the destination tree is proceeded)
*/
void arrangeChunksInTree( IChunkContainer& srcTree, IChunkContainer& destTree );
/**
Try to merge existing FREE chunks at the passed position in the child list
of the passed parent tree.
The algorithm looks at the position, before the position and after the position.
@param tree Parent tree
@param index Position in the child list of the parent tree
@return FREE chunk if available at the passed position (in case of a merge
the merged FREE chunk)
*/
Chunk* mergeFreeChunks( IChunkContainer& tree, XMP_Uns32 index );
/**
Move a range of chunks from one container to another starting at the start index up to the
end of the srcTree.
@param srcTree Source container
@param destTree Destination container
@param start Start index of source container
*/
void moveChunks( IChunkContainer& srcTree, IChunkContainer& destTree, XMP_Uns32 start );
private:
std::vector<ChunkPath>* mMovablePaths;
};
} // IChunkBehavior
#endif
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