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<div class="navpath"><a class="el" href="namespaceExiv2.html">Exiv2</a>::<a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a>
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<h1>Exiv2::BasicIo Class Reference</h1><!-- doxytag: class="Exiv2::BasicIo" -->An interface for simple binary IO.
<a href="#_details">More...</a>
<p>
<code>#include <basicio.hpp></code>
<p>
<div class="dynheader">
Inheritance diagram for Exiv2::BasicIo:</div>
<div class="dynsection">
<p><center><img src="classExiv2_1_1BasicIo__inherit__graph.png" border="0" usemap="#Exiv2_1_1BasicIo__inherit__map" alt="Inheritance graph"></center>
<map name="Exiv2_1_1BasicIo__inherit__map">
<area shape="rect" id="node3" href="classExiv2_1_1FileIo.html" title="Provides binary file IO by implementing the BasicIo interface." alt="" coords="5,80,157,107"><area shape="rect" id="node5" href="classExiv2_1_1MemIo.html" title="Provides binary IO on blocks of memory by implementing the BasicIo interface. A copy-on-write..." alt="" coords="181,80,323,107"></map>
<center><font size="2">[<a href="graph_legend.html">legend</a>]</font></center></div>
<p>
<a href="classExiv2_1_1BasicIo-members.html">List of all members.</a><table border="0" cellpadding="0" cellspacing="0">
<tr><td></td></tr>
<tr><td colspan="2"><br><h2>Public Types</h2></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">enum </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#1d23c3bf7618f2ee6ebb5cf033b10911">Position</a> { <b>beg</b>,
<b>cur</b>,
<b>end</b>
}</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Seek starting positions. <br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="f8f989522925b884d8c9d3a257265fa1"></a><!-- doxytag: member="Exiv2::BasicIo::AutoPtr" ref="f8f989522925b884d8c9d3a257265fa1" args="" -->
typedef std::auto_ptr< <a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#f8f989522925b884d8c9d3a257265fa1">AutoPtr</a></td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight"><a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> auto_ptr type. <br></td></tr>
<tr><td colspan="2"><br><h2>Public Member Functions</h2></td></tr>
<tr><td colspan="2"><div class="groupHeader">Creators</div></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="0c6658dc8caea27ac88def52ce0789bd"></a><!-- doxytag: member="Exiv2::BasicIo::~BasicIo" ref="0c6658dc8caea27ac88def52ce0789bd" args="()" -->
virtual </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#0c6658dc8caea27ac88def52ce0789bd">~BasicIo</a> ()</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Destructor. <br></td></tr>
<tr><td colspan="2"><div class="groupHeader">Manipulators</div></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#1beff0dcdf03510bad13b6946379c5f2">open</a> ()=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Open the IO source using the default access mode. The default mode should allow for reading and writing. <a href="#1beff0dcdf03510bad13b6946379c5f2"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#67ae3ca0f8aece92a7b7749dfb02edde">close</a> ()=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Close the IO source. After closing a <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance can not be read or written. Closing flushes any unwritten data. It is safe to call close on a closed instance. <a href="#67ae3ca0f8aece92a7b7749dfb02edde"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual long </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#c548d52ef633ac425bd01d17ccd2e7e4">write</a> (const <a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> *data, long wcount)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Write data to the IO source. Current IO position is advanced by the number of bytes written. <a href="#c548d52ef633ac425bd01d17ccd2e7e4"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual long </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#31334606e230bbe94d6b8768d3c6d75f">write</a> (<a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a> &src)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Write data that is read from another <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance to the IO source. Current IO position is advanced by the number of bytes written. <a href="#31334606e230bbe94d6b8768d3c6d75f"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#d16a1fab0f122c8ca11b86d09b03b9a7">putb</a> (<a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> data)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Write one byte to the IO source. Current IO position is advanced by one byte. <a href="#d16a1fab0f122c8ca11b86d09b03b9a7"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual <a class="el" href="classExiv2_1_1DataBuf.html">DataBuf</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#8c9e6c7377b642afbb2c14a0e3896917">read</a> (long rcount)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Read data from the IO source. Reading starts at the current IO position and the position is advanced by the number of bytes read. <a href="#8c9e6c7377b642afbb2c14a0e3896917"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual long </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#ec8cb20c86e72b87577370a28d66a0ca">read</a> (<a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> *buf, long rcount)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Read data from the IO source. Reading starts at the current IO position and the position is advanced by the number of bytes read. <a href="#ec8cb20c86e72b87577370a28d66a0ca"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#648bc0d9b1a79e34684375074d806534">getb</a> ()=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Read one byte from the IO source. Current IO position is advanced by one byte. <a href="#648bc0d9b1a79e34684375074d806534"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#cb964ff603c96da8711baddb66a385a4">transfer</a> (<a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a> &src)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Remove all data from this object's IO source and then transfer data from the <em>src</em> <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> object into this object. <a href="#cb964ff603c96da8711baddb66a385a4"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#561221bbe1d215b4d6b5ceceaa2e9a97">seek</a> (long offset, <a class="el" href="classExiv2_1_1BasicIo.html#1d23c3bf7618f2ee6ebb5cf033b10911">Position</a> pos)=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Move the current IO position. <a href="#561221bbe1d215b4d6b5ceceaa2e9a97"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual const <a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#56dedc1898b73b376280fc9c9d656d9b">mmap</a> ()=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Direct access to the IO data. For files, this is done by mapping the file into the process's address space; for memory blocks, this allows direct access to the memory block. <a href="#56dedc1898b73b376280fc9c9d656d9b"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="501ac3b9cdbcf80456d12b9db0e22c68"></a><!-- doxytag: member="Exiv2::BasicIo::munmap" ref="501ac3b9cdbcf80456d12b9db0e22c68" args="()=0" -->
virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#501ac3b9cdbcf80456d12b9db0e22c68">munmap</a> ()=0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Remove a mapping established with <a class="el" href="classExiv2_1_1BasicIo.html#56dedc1898b73b376280fc9c9d656d9b" title="Direct access to the IO data. For files, this is done by mapping the file into the...">mmap()</a>. <br></td></tr>
<tr><td colspan="2"><div class="groupHeader">Accessors</div></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual long </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#eb9673a48a7af7376b7018998fb552e6">tell</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Get the current IO position. <a href="#eb9673a48a7af7376b7018998fb552e6"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual long </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#01903a1a2310197eb7e3fd41bedc3054">size</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Get the current size of the IO source in bytes. <a href="#01903a1a2310197eb7e3fd41bedc3054"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="17744832ee807c68f9c8d744692d9aaf"></a><!-- doxytag: member="Exiv2::BasicIo::isopen" ref="17744832ee807c68f9c8d744692d9aaf" args="() const =0" -->
virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#17744832ee807c68f9c8d744692d9aaf">isopen</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Returns true if the IO source is open, otherwise false. <br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="d674727cddbf9cea627423620a8bb3d0"></a><!-- doxytag: member="Exiv2::BasicIo::error" ref="d674727cddbf9cea627423620a8bb3d0" args="() const =0" -->
virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#d674727cddbf9cea627423620a8bb3d0">error</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Returns 0 if the IO source is in a valid state, otherwise nonzero. <br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="29b826f89a8aac3c83ece6f8f343ed72"></a><!-- doxytag: member="Exiv2::BasicIo::eof" ref="29b826f89a8aac3c83ece6f8f343ed72" args="() const =0" -->
virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#29b826f89a8aac3c83ece6f8f343ed72">eof</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Returns true if the IO position has reach the end, otherwise false. <br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="8c4af60d14039fd99d36c73ce8354c15"></a><!-- doxytag: member="Exiv2::BasicIo::path" ref="8c4af60d14039fd99d36c73ce8354c15" args="() const =0" -->
virtual std::string </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#8c4af60d14039fd99d36c73ce8354c15">path</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Return the path to the IO resource. Often used to form comprehensive error messages where only a <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance is available. <br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual <a class="el" href="classExiv2_1_1BasicIo.html#f8f989522925b884d8c9d3a257265fa1">BasicIo::AutoPtr</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#ec9dd2dd223ce57650462c74a0770502">temporary</a> () const =0</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Returns a temporary data storage location. This is often needed to rewrite an IO source. <a href="#ec9dd2dd223ce57650462c74a0770502"></a><br></td></tr>
<tr><td colspan="2"><br><h2>Protected Member Functions</h2></td></tr>
<tr><td colspan="2"><div class="groupHeader">Creators</div></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="c726bef377a5da282b0f2cadb5b779be"></a><!-- doxytag: member="Exiv2::BasicIo::BasicIo" ref="c726bef377a5da282b0f2cadb5b779be" args="()" -->
</td><td class="memItemRight" valign="bottom"><a class="el" href="classExiv2_1_1BasicIo.html#c726bef377a5da282b0f2cadb5b779be">BasicIo</a> ()</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Default Constructor. <br></td></tr>
</table>
<hr><a name="_details"></a><h2>Detailed Description</h2>
An interface for simple binary IO.
<p>
Designed to have semantics and names similar to those of C style FILE* operations. Subclasses should all behave the same so that they can be interchanged. <hr><h2>Member Function Documentation</h2>
<a class="anchor" name="67ae3ca0f8aece92a7b7749dfb02edde"></a><!-- doxytag: member="Exiv2::BasicIo::close" ref="67ae3ca0f8aece92a7b7749dfb02edde" args="()=0" -->
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<td class="memname">virtual int Exiv2::BasicIo::close </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Close the IO source. After closing a <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance can not be read or written. Closing flushes any unwritten data. It is safe to call close on a closed instance.
<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>0 if successful;<br>
Nonzero if failure. </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#794be686e28524d9eed2a0811d477d3b">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#f2263c6d49984da7ce38daed9f327b1e">Exiv2::MemIo</a>.</p>
</div>
</div><p>
<a class="anchor" name="648bc0d9b1a79e34684375074d806534"></a><!-- doxytag: member="Exiv2::BasicIo::getb" ref="648bc0d9b1a79e34684375074d806534" args="()=0" -->
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<td class="memname">virtual int Exiv2::BasicIo::getb </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Read one byte from the IO source. Current IO position is advanced by one byte.
<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>The byte read from the IO source if successful;<br>
EOF if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#0741ebecd2ea70f86c40457c33cd6c66">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#b5d5467941f00e4bb47a411182955d44">Exiv2::MemIo</a>.</p>
</div>
</div><p>
<a class="anchor" name="56dedc1898b73b376280fc9c9d656d9b"></a><!-- doxytag: member="Exiv2::BasicIo::mmap" ref="56dedc1898b73b376280fc9c9d656d9b" args="()=0" -->
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<td class="memname">virtual const <a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a>* Exiv2::BasicIo::mmap </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
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</table>
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<div class="memdoc">
<p>
Direct access to the IO data. For files, this is done by mapping the file into the process's address space; for memory blocks, this allows direct access to the memory block.
<p>
Todo: This is currently only for read access.
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#262356ec3c52ccdba2862b289f8e5e37">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#b3e20f77251ba80e65cd6e6ac93efd76">Exiv2::MemIo</a>.</p>
</div>
</div><p>
<a class="anchor" name="1beff0dcdf03510bad13b6946379c5f2"></a><!-- doxytag: member="Exiv2::BasicIo::open" ref="1beff0dcdf03510bad13b6946379c5f2" args="()=0" -->
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<td class="memname">virtual int Exiv2::BasicIo::open </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Open the IO source using the default access mode. The default mode should allow for reading and writing.
<p>
This method can also be used to "reopen" an IO source which will flush any unwritten data and reset the IO position to the start. Subclasses may provide custom methods to allow for opening IO sources differently.<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>0 if successful;<br>
Nonzero if failure. </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#88b8ab582237647a4c28120c15030a71">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#cbc7726037d2eb0dbbdef649f30ebc5c">Exiv2::MemIo</a>.</p>
<p>Referenced by <a class="el" href="image_8cpp_source.html#l00294">Exiv2::ImageFactory::getType()</a>.</p>
</div>
</div><p>
<a class="anchor" name="d16a1fab0f122c8ca11b86d09b03b9a7"></a><!-- doxytag: member="Exiv2::BasicIo::putb" ref="d16a1fab0f122c8ca11b86d09b03b9a7" args="(byte data)=0" -->
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<td class="memname">virtual int Exiv2::BasicIo::putb </td>
<td>(</td>
<td class="paramtype"><a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> </td>
<td class="paramname"> <em>data</em> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Write one byte to the IO source. Current IO position is advanced by one byte.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>data</em> </td><td>The single byte to be written. </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>The value of the byte written if successful;<br>
EOF if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#581c10115b42fc3a6c2b177337988922">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#5999ba245f79d581c9c5a16982d736b6">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="ec8cb20c86e72b87577370a28d66a0ca"></a><!-- doxytag: member="Exiv2::BasicIo::read" ref="ec8cb20c86e72b87577370a28d66a0ca" args="(byte *buf, long rcount)=0" -->
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<td class="memname">virtual long Exiv2::BasicIo::read </td>
<td>(</td>
<td class="paramtype"><a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> * </td>
<td class="paramname"> <em>buf</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">long </td>
<td class="paramname"> <em>rcount</em></td><td> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td><td><code> [pure virtual]</code></td>
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<p>
Read data from the IO source. Reading starts at the current IO position and the position is advanced by the number of bytes read.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>buf</em> </td><td>Pointer to a block of memory into which the read data is stored. The memory block must be at least <em>rcount</em> bytes long. </td></tr>
<tr><td valign="top"></td><td valign="top"><em>rcount</em> </td><td>Maximum number of bytes to read. Fewer bytes may be read if <em>rcount</em> bytes are not available. </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>Number of bytes read from IO source successfully;<br>
0 if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#a54d2b91db8ac2073fbe438ef19ac055">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#7de679e4366d070dc6604db1d22275ce">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="8c9e6c7377b642afbb2c14a0e3896917"></a><!-- doxytag: member="Exiv2::BasicIo::read" ref="8c9e6c7377b642afbb2c14a0e3896917" args="(long rcount)=0" -->
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<td class="memname">virtual <a class="el" href="classExiv2_1_1DataBuf.html">DataBuf</a> Exiv2::BasicIo::read </td>
<td>(</td>
<td class="paramtype">long </td>
<td class="paramname"> <em>rcount</em> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
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<p>
Read data from the IO source. Reading starts at the current IO position and the position is advanced by the number of bytes read.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>rcount</em> </td><td>Maximum number of bytes to read. Fewer bytes may be read if <em>rcount</em> bytes are not available. </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd><a class="el" href="classExiv2_1_1DataBuf.html" title="Utility class containing a character array. All it does is to take care of memory...">DataBuf</a> instance containing the bytes read. Use the <a class="el" href="classExiv2_1_1DataBuf.html#5e6028d5cdae2e149749667cf66c3e91" title="The current size of the buffer.">DataBuf::size_</a> member to find the number of bytes read. <a class="el" href="classExiv2_1_1DataBuf.html#5e6028d5cdae2e149749667cf66c3e91" title="The current size of the buffer.">DataBuf::size_</a> will be 0 on failure. </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#48ed0700ccfb60a6a435ab7086734965">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#3d45d5be7b0e25c32d37d5055da0adc0">Exiv2::MemIo</a>.</p>
<p>Referenced by <a class="el" href="crwimage_8cpp_source.html#l00225">Exiv2::isCrwType()</a>, <a class="el" href="jp2image_8cpp_source.html#l00617">Exiv2::isJp2Type()</a>, <a class="el" href="pngimage_8cpp_source.html#l00391">Exiv2::isPngType()</a>, and <a class="el" href="psdimage_8cpp_source.html#l00651">Exiv2::isPsdType()</a>.</p>
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<a class="anchor" name="561221bbe1d215b4d6b5ceceaa2e9a97"></a><!-- doxytag: member="Exiv2::BasicIo::seek" ref="561221bbe1d215b4d6b5ceceaa2e9a97" args="(long offset, Position pos)=0" -->
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<td class="memname">virtual int Exiv2::BasicIo::seek </td>
<td>(</td>
<td class="paramtype">long </td>
<td class="paramname"> <em>offset</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="classExiv2_1_1BasicIo.html#1d23c3bf7618f2ee6ebb5cf033b10911">Position</a> </td>
<td class="paramname"> <em>pos</em></td><td> </td>
</tr>
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<td></td>
<td>)</td>
<td></td><td></td><td><code> [pure virtual]</code></td>
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<p>
Move the current IO position.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>offset</em> </td><td>Number of bytes to move the position relative to the starting position specified by <em>pos</em> </td></tr>
<tr><td valign="top"></td><td valign="top"><em>pos</em> </td><td>Position from which the seek should start </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>0 if successful;<br>
Nonzero if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#889840bb9764987ce7a13c10d3ddcf2e">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#b4a12d5b5ed6f8447c7167942c4aa4ae">Exiv2::MemIo</a>.</p>
<p>Referenced by <a class="el" href="crwimage_8cpp_source.html#l00225">Exiv2::isCrwType()</a>, <a class="el" href="jp2image_8cpp_source.html#l00617">Exiv2::isJp2Type()</a>, <a class="el" href="pngimage_8cpp_source.html#l00391">Exiv2::isPngType()</a>, and <a class="el" href="psdimage_8cpp_source.html#l00651">Exiv2::isPsdType()</a>.</p>
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<a class="anchor" name="01903a1a2310197eb7e3fd41bedc3054"></a><!-- doxytag: member="Exiv2::BasicIo::size" ref="01903a1a2310197eb7e3fd41bedc3054" args="() const =0" -->
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<td class="memname">virtual long Exiv2::BasicIo::size </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const<code> [pure virtual]</code></td>
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<p>
Get the current size of the IO source in bytes.
<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>Size of the IO source in bytes;<br>
-1 if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#d4ca7c5f50eac795ab981c5913d12345">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#5c58a8d37b4546f1c06cb29099d72ae3">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="eb9673a48a7af7376b7018998fb552e6"></a><!-- doxytag: member="Exiv2::BasicIo::tell" ref="eb9673a48a7af7376b7018998fb552e6" args="() const =0" -->
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<td class="memname">virtual long Exiv2::BasicIo::tell </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const<code> [pure virtual]</code></td>
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<p>
Get the current IO position.
<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>Offset from the start of IO if successful;<br>
-1 if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#15209532fb5b3991b033046d50b30b40">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#e3d499cec109ea971b95ce088ae0473c">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="ec9dd2dd223ce57650462c74a0770502"></a><!-- doxytag: member="Exiv2::BasicIo::temporary" ref="ec9dd2dd223ce57650462c74a0770502" args="() const =0" -->
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<td class="memname">virtual <a class="el" href="classExiv2_1_1BasicIo.html#f8f989522925b884d8c9d3a257265fa1">BasicIo::AutoPtr</a> Exiv2::BasicIo::temporary </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const<code> [pure virtual]</code></td>
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<p>
Returns a temporary data storage location. This is often needed to rewrite an IO source.
<p>
For example, data may be read from the original IO source, modified in some way, and then saved to the temporary instance. After the operation is complete, the <a class="el" href="classExiv2_1_1BasicIo.html#cb964ff603c96da8711baddb66a385a4" title="Remove all data from this object's IO source and then transfer data from the...">BasicIo::transfer</a> method can be used to replace the original IO source with the modified version. Subclasses are free to return any class that derives from <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a>.<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>An instance of <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> on success </dd></dl>
<dl compact><dt><b>Exceptions:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em><a class="el" href="classExiv2_1_1Error.html" title="Simple error class used for exceptions. An output operator is provided to print errors...">Error</a></em> </td><td>In case of failure </td></tr>
</table>
</dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#02656814c3dd891fcd5537eb70920c25">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#420aec675d4fabb48293003d9e7cce76">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="cb964ff603c96da8711baddb66a385a4"></a><!-- doxytag: member="Exiv2::BasicIo::transfer" ref="cb964ff603c96da8711baddb66a385a4" args="(BasicIo &src)=0" -->
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<td class="memname">virtual void Exiv2::BasicIo::transfer </td>
<td>(</td>
<td class="paramtype"><a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a> & </td>
<td class="paramname"> <em>src</em> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
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<p>
Remove all data from this object's IO source and then transfer data from the <em>src</em> <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> object into this object.
<p>
The source object is invalidated by this operation and should not be used after this method returns. This method exists primarily to be used with the <a class="el" href="classExiv2_1_1BasicIo.html#ec9dd2dd223ce57650462c74a0770502" title="Returns a temporary data storage location. This is often needed to rewrite an IO...">BasicIo::temporary()</a> method.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>src</em> </td><td>Reference to another <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance. The entire contents of src are transferred to this object. The <em>src</em> object is invalidated by the method. </td></tr>
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</dl>
<dl compact><dt><b>Exceptions:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em><a class="el" href="classExiv2_1_1Error.html" title="Simple error class used for exceptions. An output operator is provided to print errors...">Error</a></em> </td><td>In case of failure </td></tr>
</table>
</dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#a860f63e95d227be73b86b2fe64ad7b8">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#223908a596491d75cebbb7a6f9c1559f">Exiv2::MemIo</a>.</p>
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</div><p>
<a class="anchor" name="31334606e230bbe94d6b8768d3c6d75f"></a><!-- doxytag: member="Exiv2::BasicIo::write" ref="31334606e230bbe94d6b8768d3c6d75f" args="(BasicIo &src)=0" -->
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<td class="memname">virtual long Exiv2::BasicIo::write </td>
<td>(</td>
<td class="paramtype"><a class="el" href="classExiv2_1_1BasicIo.html">BasicIo</a> & </td>
<td class="paramname"> <em>src</em> </td>
<td> ) </td>
<td><code> [pure virtual]</code></td>
</tr>
</table>
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<p>
Write data that is read from another <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance to the IO source. Current IO position is advanced by the number of bytes written.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>src</em> </td><td>Reference to another <a class="el" href="classExiv2_1_1BasicIo.html" title="An interface for simple binary IO.">BasicIo</a> instance. Reading start at the source's current IO position </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>Number of bytes written to IO source successfully;<br>
0 if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#7fd4444f019a2cfbd0e925e9b181c95c">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#84c854a02e45febea5c0dfc0192e4b6e">Exiv2::MemIo</a>.</p>
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<a class="anchor" name="c548d52ef633ac425bd01d17ccd2e7e4"></a><!-- doxytag: member="Exiv2::BasicIo::write" ref="c548d52ef633ac425bd01d17ccd2e7e4" args="(const byte *data, long wcount)=0" -->
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<td class="memname">virtual long Exiv2::BasicIo::write </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="namespaceExiv2.html#16f60a5bd4207fe155f6cf93a15efa72">byte</a> * </td>
<td class="paramname"> <em>data</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">long </td>
<td class="paramname"> <em>wcount</em></td><td> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td><td><code> [pure virtual]</code></td>
</tr>
</table>
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<div class="memdoc">
<p>
Write data to the IO source. Current IO position is advanced by the number of bytes written.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>data</em> </td><td>Pointer to data. Data must be at least <em>wcount</em> bytes long </td></tr>
<tr><td valign="top"></td><td valign="top"><em>wcount</em> </td><td>Number of bytes to be written. </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>Number of bytes written to IO source successfully;<br>
0 if failure; </dd></dl>
<p>Implemented in <a class="el" href="classExiv2_1_1FileIo.html#1a576f408124d428d5c446a19e2a504d">Exiv2::FileIo</a>, and <a class="el" href="classExiv2_1_1MemIo.html#79993ba49c24c36b30f444c218ce4579">Exiv2::MemIo</a>.</p>
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<hr>The documentation for this class was generated from the following file:<ul>
<li><a class="el" href="basicio_8hpp.html">basicio.hpp</a></ul>
</div>
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