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27 
28 #ifndef _COMPHELPER_STREAMSECTION_HXX_
29 #define _COMPHELPER_STREAMSECTION_HXX_
30 
31 #include <com/sun/star/io/XMarkableStream.hpp>
32 #include <com/sun/star/io/XDataInputStream.hpp>
33 #include <com/sun/star/io/XDataOutputStream.hpp>
34 #include "comphelper/comphelperdllapi.h"
35 
36 namespace comphelper
37 {
38 
39 	namespace stario	= ::com::sun::star::io;
40 	namespace staruno	= ::com::sun::star::uno;
41 
42 /** implements handling for compatibly reading/writing data from/into an input/output stream.
43 	data written in a block secured by this class should be readable by older versions which
44 	use the same mechanism.
45 
46 	@author	Frank Schoenheit
47 	@since	00/26/05
48 */
49 
50 class COMPHELPER_DLLPUBLIC OStreamSection
51 {
52 	staruno::Reference< stario::XMarkableStream >		m_xMarkStream;
53 	staruno::Reference< stario::XDataInputStream >		m_xInStream;
54 	staruno::Reference< stario::XDataOutputStream >		m_xOutStream;
55 
56 	sal_Int32	m_nBlockStart;
57 	sal_Int32	m_nBlockLen;
58 
59 public:
60 	/**	starts reading of a "skippable" section of data within the given input stream<BR>
61 		@param		_rxInput	the stream to read from. Must support the
62 								<type scope="com::sun::star::io">XMarkableStream</type> interface
63 	*/
64 	OStreamSection(const staruno::Reference< stario::XDataInputStream >& _rxInput);
65 
66 	/**	starts writing of a "skippable" section of data into the given output stream
67 		@param		_rxOutput			the stream the stream to write to. Must support the
68 										<type scope="com::sun::star::io">XMarkableStream</type> interface
69 		@param		_nPresumedLength	estimation for the length of the upcoming section. If greater 0, this
70 										value will be written as section length and corrected (in the dtor) only if
71 										needed. If you know how much bytes you are about to write, you may
72 										want to use this param, saving some stream operations this way.
73 	*/
74 	OStreamSection(const staruno::Reference< stario::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength = 0);
75 
76 	/** dtor. <BR>If constructed for writing, the section "opened" by this object will be "closed".<BR>
77 		If constructed for reading, any remaining bytes 'til the end of the section will be skipped.
78 	*/
79 	~OStreamSection();
80 	/**
81 		return the number of bytes which are still available
82 	*/
83 	sal_Int32 available();
84 };
85 
86 }	// namespace comphelper
87 
88 #endif // _COMPHELPER_STREAMSECTION_HXX_
89