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21 
22 
23 
24 #ifndef _COMPHELPER_STREAMSECTION_HXX_
25 #define _COMPHELPER_STREAMSECTION_HXX_
26 
27 #include <com/sun/star/io/XMarkableStream.hpp>
28 #include <com/sun/star/io/XDataInputStream.hpp>
29 #include <com/sun/star/io/XDataOutputStream.hpp>
30 #include "comphelper/comphelperdllapi.h"
31 
32 namespace comphelper
33 {
34 
35 	namespace stario	= ::com::sun::star::io;
36 	namespace staruno	= ::com::sun::star::uno;
37 
38 /** implements handling for compatibly reading/writing data from/into an input/output stream.
39 	data written in a block secured by this class should be readable by older versions which
40 	use the same mechanism.
41 
42 	@author	Frank Schoenheit
43 	@since	00/26/05
44 */
45 
46 class COMPHELPER_DLLPUBLIC OStreamSection
47 {
48 	staruno::Reference< stario::XMarkableStream >		m_xMarkStream;
49 	staruno::Reference< stario::XDataInputStream >		m_xInStream;
50 	staruno::Reference< stario::XDataOutputStream >		m_xOutStream;
51 
52 	sal_Int32	m_nBlockStart;
53 	sal_Int32	m_nBlockLen;
54 
55 public:
56 	/**	starts reading of a "skippable" section of data within the given input stream<BR>
57 		@param		_rxInput	the stream to read from. Must support the
58 								<type scope="com::sun::star::io">XMarkableStream</type> interface
59 	*/
60 	OStreamSection(const staruno::Reference< stario::XDataInputStream >& _rxInput);
61 
62 	/**	starts writing of a "skippable" section of data into the given output stream
63 		@param		_rxOutput			the stream the stream to write to. Must support the
64 										<type scope="com::sun::star::io">XMarkableStream</type> interface
65 		@param		_nPresumedLength	estimation for the length of the upcoming section. If greater 0, this
66 										value will be written as section length and corrected (in the dtor) only if
67 										needed. If you know how much bytes you are about to write, you may
68 										want to use this param, saving some stream operations this way.
69 	*/
70 	OStreamSection(const staruno::Reference< stario::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength = 0);
71 
72 	/** dtor. <BR>If constructed for writing, the section "opened" by this object will be "closed".<BR>
73 		If constructed for reading, any remaining bytes 'til the end of the section will be skipped.
74 	*/
75 	~OStreamSection();
76 	/**
77 		return the number of bytes which are still available
78 	*/
79 	sal_Int32 available();
80 };
81 
82 }	// namespace comphelper
83 
84 #endif // _COMPHELPER_STREAMSECTION_HXX_
85