<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Class Poco::Checksum</title> <meta http-equiv="content-type" content="text/html; charset=utf-8"/> <meta name="author" content="Applied Informatics Software Engineering GmbH and Contributors"/> <meta name="publisher" content="Applied Informatics Software Engineering GmbH and Contributors"/> <meta name="copyright" content="Copyright (c) 2009, Applied Informatics Software Engineering GmbH and Contributors"/> <meta name="language" content="en"/> <meta name="date" content="2009-11-24"/> <meta name="generator" content="PocoDoc"/> <link rel="stylesheet" href="css/styles.css" type="text/css"/> </head> <body bgcolor="#ffffff" leftmargin="0" topmargin="0"> <div class="header"> <h1 class="namespace"><a href="Poco.html" class="namespace">Poco</a></h1> <h1 class="symbol">class Checksum</h1> </div> <div class="body"> <p> <b>Library:</b> Foundation<br /> <b>Package:</b> Core<br /> <b>Header:</b> Poco/Checksum.h</p> <h2>Description</h2> <div class="description"> <p>This class calculates CRC-32 or Adler-32 checksums for arbitrary data. </p> <p>A cyclic redundancy check (CRC) is a type of hash function, which is used to produce a small, fixed-size checksum of a larger block of data, such as a packet of network traffic or a computer file. CRC-32 is one of the most commonly used CRC algorithms. </p> <p>Adler-32 is a checksum algorithm which was invented by Mark Adler. It is almost as reliable as a 32-bit cyclic redundancy check for protecting against accidental modification of data, such as distortions occurring during a transmission, but is significantly faster to calculate in software. </p> </div> <h2>Member Summary</h2> <p><b>Member Functions: </b><a href="Poco.Checksum.html#4173" title="Poco::Checksum::checksum()">checksum</a>, <a href="Poco.Checksum.html#4174" title="Poco::Checksum::type()">type</a>, <a href="Poco.Checksum.html#4166" title="Poco::Checksum::update()">update</a></p> <h2>Enumerations</h2> <h3><a name="4159">Type</a></h3> <div class="description"> <p></p> </div> <p class="decl"><a name="4160">TYPE_ADLER32</a> = 0</p> <div class="description"> <p></p> </div> <p class="decl"><a name="4161">TYPE_CRC32</a></p> <div class="description"> <p></p> </div> <h2>Constructors</h2> <h3><a name="4162">Checksum</a></h3> <p class="decl"><a href="Poco.Checksum.html" title="class Poco::Checksum">Checksum</a>();</p> <div class="description"> <p>Creates a CRC-32 checksum initialized to 0. </p> </div> <h3><a name="4163">Checksum</a></h3> <p class="decl"><a href="Poco.Checksum.html" title="class Poco::Checksum">Checksum</a>(<br /> <a href="Poco.Checksum.html#4159" title="enum Poco::Checksum::Type">Type</a> t<br />);</p> <div class="description"> <p>Creates the <a href="Poco.Checksum.html" title="class Poco::Checksum">Checksum</a>, using the given type. </p> </div> <h2>Destructor</h2> <h3><a name="4165">~Checksum</a></h3> <p class="decl">~<a href="Poco.Checksum.html" title="class Poco::Checksum">Checksum</a>();</p> <div class="description"> <p>Destroys the <a href="Poco.Checksum.html" title="class Poco::Checksum">Checksum</a>. </p> </div> <h2>Member Functions</h2> <h3><a name="4173">checksum</a> <img src="images/inline.gif" alt="inline" title="inline" style="vertical-align:baseline;" border="0" /> </h3> <p class="decl"><a href="Poco.html#11354" title="Poco::UInt32">Poco::UInt32</a> checksum() const;</p> <div class="description"> <p>Returns the calculated checksum. </p> </div> <h3><a name="4174">type</a> <img src="images/inline.gif" alt="inline" title="inline" style="vertical-align:baseline;" border="0" /> </h3> <p class="decl"><a href="Poco.Checksum.html#4159" title="enum Poco::Checksum::Type">Type</a> type() const;</p> <div class="description"> <p>Which type of checksum are we calulcating </p> </div> <h3><a name="4166">update</a> <img src="images/inline.gif" alt="inline" title="inline" style="vertical-align:baseline;" border="0" /> </h3> <p class="decl">void update(<br /> const char * data,<br /> unsigned length<br />);</p> <div class="description"> <p>Updates the checksum with the given data. </p> </div> <h3><a name="4169">update</a></h3> <p class="decl">void update(<br /> const std::string & data<br />);</p> <div class="description"> <p>Updates the checksum with the given data. </p> </div> <h3><a name="4171">update</a></h3> <p class="decl">void update(<br /> char data<br />);</p> <div class="description"> <p>Updates the checksum with the given data. </p> </div> <p class="footer">POCO C++ Libraries 1.3.6-all<br /> Copyright © 2009, <a href="http://pocoproject.org/" target="_blank">Applied Informatics Software Engineering GmbH and Contributors</a></p> </div> </body> </html>
