<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qabstractnetworkcache.cpp --> <title>QAbstractNetworkCache Class | Qt Network 5.12.6</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtnetwork-index.html">Qt Network</a></td><td ><a href="qtnetwork-module.html">C++ Classes</a></td><td >QAbstractNetworkCache</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtnetwork-index.html">Qt 5.12.6 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#public-slots">Public Slots</a></li> <li class="level1"><a href="#static-public-members">Static Public Members</a></li> <li class="level1"><a href="#protected-functions">Protected Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QAbstractNetworkCache Class</h1> <!-- $$$QAbstractNetworkCache-brief --> <p>The <a href="qabstractnetworkcache.html">QAbstractNetworkCache</a> class provides the interface for cache implementations. <a href="#details">More...</a></p> <!-- @@@QAbstractNetworkCache --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QAbstractNetworkCache></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += network</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 4.5</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherits:</td><td class="memItemRight bottomAlign"> <a href="../qtcore/qobject.html">QObject</a></td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherited By:</td><td class="memItemRight bottomAlign"> <p><a href="qnetworkdiskcache.html">QNetworkDiskCache</a></p> </td></tr></table></div><ul> <li><a href="qabstractnetworkcache-members.html">List of all members, including inherited members</a></li> <li><a href="qabstractnetworkcache-obsolete.html">Obsolete members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#dtor.QAbstractNetworkCache">~QAbstractNetworkCache</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual qint64 </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#cacheSize">cacheSize</a></b>() const = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual QIODevice *</td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#data">data</a></b>(const QUrl &<i>url</i>) = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual void </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#insert">insert</a></b>(QIODevice *<i>device</i>) = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual QNetworkCacheMetaData </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#metaData">metaData</a></b>(const QUrl &<i>url</i>) = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual QIODevice *</td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#prepare">prepare</a></b>(const QNetworkCacheMetaData &<i>metaData</i>) = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#remove">remove</a></b>(const QUrl &<i>url</i>) = 0</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual void </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#updateMetaData">updateMetaData</a></b>(const QNetworkCacheMetaData &<i>metaData</i>) = 0</td></tr> </table></div> <ul> <li class="fn">31 public functions inherited from <a href="../qtcore/qobject.html#public-functions">QObject</a></li> </ul> <a name="public-slots"></a> <h2 id="public-slots">Public Slots</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> virtual void </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#clear">clear</a></b>() = 0</td></tr> </table></div> <ul> <li class="fn">1 public slot inherited from <a href="../qtcore/qobject.html#public-slots">QObject</a></li> </ul> <a name="static-public-members"></a> <h2 id="static-public-members">Static Public Members</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> const QMetaObject </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#staticMetaObject-var">staticMetaObject</a></b></td></tr> </table></div> <ul> <li class="fn">9 static public members inherited from <a href="../qtcore/qobject.html#static-public-members">QObject</a></li> </ul> <a name="protected-functions"></a> <h2 id="protected-functions">Protected Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qabstractnetworkcache.html#QAbstractNetworkCache">QAbstractNetworkCache</a></b>(QObject *<i>parent</i> = nullptr)</td></tr> </table></div> <ul> <li class="fn">9 protected functions inherited from <a href="../qtcore/qobject.html#protected-functions">QObject</a></li> </ul> <h3>Additional Inherited Members</h3> <ul> <li class="fn">1 property inherited from <a href="../qtcore/qobject.html#properties">QObject</a></li> <li class="fn">2 signals inherited from <a href="../qtcore/qobject.html#signals">QObject</a></li> </ul> <a name="details"></a> <!-- $$$QAbstractNetworkCache-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qabstractnetworkcache.html">QAbstractNetworkCache</a> class provides the interface for cache implementations.</p> <p><a href="qabstractnetworkcache.html">QAbstractNetworkCache</a> is the base class for every standard cache that is used by <a href="qnetworkaccessmanager.html">QNetworkAccessManager</a>. <a href="qabstractnetworkcache.html">QAbstractNetworkCache</a> is an abstract class and cannot be instantiated.</p> </div> <p><b>See also </b><a href="qnetworkdiskcache.html">QNetworkDiskCache</a>.</p> <!-- @@@QAbstractNetworkCache --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QAbstractNetworkCache[overload1]$$$QAbstractNetworkCacheQObject* --> <h3 class="fn" id="QAbstractNetworkCache"><a name="QAbstractNetworkCache"></a><code>[protected] </code>QAbstractNetworkCache::<span class="name">QAbstractNetworkCache</span>(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> *<i>parent</i> = nullptr)</h3> <p>Constructs an abstract network cache with the given <i>parent</i>.</p> <!-- @@@QAbstractNetworkCache --> <!-- $$$~QAbstractNetworkCache[overload1]$$$~QAbstractNetworkCache --> <h3 class="fn" id="dtor.QAbstractNetworkCache"><a name="dtor.QAbstractNetworkCache"></a><code>[virtual] </code>QAbstractNetworkCache::<span class="name">~QAbstractNetworkCache</span>()</h3> <p>Destroys the cache.</p> <p>Any operations that have not been inserted are discarded.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#insert">insert</a>().</p> <!-- @@@~QAbstractNetworkCache --> <!-- $$$cacheSize[overload1]$$$cacheSize --> <h3 class="fn" id="cacheSize"><a name="cacheSize"></a><code>[pure virtual] </code><span class="type"><a href="../qtcore/qtglobal.html#qint64-typedef">qint64</a></span> QAbstractNetworkCache::<span class="name">cacheSize</span>() const</h3> <p>Returns the current size taken up by the cache. Depending upon the cache implementation this might be disk or memory size.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#clear">clear</a>().</p> <!-- @@@cacheSize --> <!-- $$$clear[overload1]$$$clear --> <h3 class="fn" id="clear"><a name="clear"></a><code>[pure virtual slot] </code><span class="type">void</span> QAbstractNetworkCache::<span class="name">clear</span>()</h3> <p>Removes all items from the cache. Unless there was failures clearing the cache <a href="qabstractnetworkcache.html#cacheSize">cacheSize</a>() should return 0 after a call to clear.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#cacheSize">cacheSize</a>() and <a href="qabstractnetworkcache.html#remove">remove</a>().</p> <!-- @@@clear --> <!-- $$$data[overload1]$$$dataconstQUrl& --> <h3 class="fn" id="data"><a name="data"></a><code>[pure virtual] </code><span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span> *QAbstractNetworkCache::<span class="name">data</span>(const <span class="type"><a href="../qtcore/qurl.html">QUrl</a></span> &<i>url</i>)</h3> <p>Returns the data associated with <i>url</i>.</p> <p>It is up to the application that requests the data to delete the <a href="../qtcore/qiodevice.html">QIODevice</a> when done with it.</p> <p>If there is no cache for <i>url</i>, the url is invalid, or if there is an internal cache error 0 is returned.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#metaData">metaData</a>() and <a href="qabstractnetworkcache.html#prepare">prepare</a>().</p> <!-- @@@data --> <!-- $$$insert[overload1]$$$insertQIODevice* --> <h3 class="fn" id="insert"><a name="insert"></a><code>[pure virtual] </code><span class="type">void</span> QAbstractNetworkCache::<span class="name">insert</span>(<span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span> *<i>device</i>)</h3> <p>Inserts the data in <i>device</i> and the prepared meta data into the cache. After this function is called the data and meta data should be retrievable using <a href="qabstractnetworkcache.html#data">data</a>() and <a href="qabstractnetworkcache.html#metaData">metaData</a>().</p> <p>To cancel a prepared inserted call <a href="qabstractnetworkcache.html#remove">remove</a>() on the metadata's url.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#prepare">prepare</a>() and <a href="qabstractnetworkcache.html#remove">remove</a>().</p> <!-- @@@insert --> <!-- $$$metaData[overload1]$$$metaDataconstQUrl& --> <h3 class="fn" id="metaData"><a name="metaData"></a><code>[pure virtual] </code><span class="type"><a href="qnetworkcachemetadata.html">QNetworkCacheMetaData</a></span> QAbstractNetworkCache::<span class="name">metaData</span>(const <span class="type"><a href="../qtcore/qurl.html">QUrl</a></span> &<i>url</i>)</h3> <p>Returns the meta data for the url <i>url</i>.</p> <p>If the url is valid and the cache contains the data for url, a valid <a href="qnetworkcachemetadata.html">QNetworkCacheMetaData</a> is returned.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#updateMetaData">updateMetaData</a>() and <a href="qabstractnetworkcache.html#data">data</a>().</p> <!-- @@@metaData --> <!-- $$$prepare[overload1]$$$prepareconstQNetworkCacheMetaData& --> <h3 class="fn" id="prepare"><a name="prepare"></a><code>[pure virtual] </code><span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span> *QAbstractNetworkCache::<span class="name">prepare</span>(const <span class="type"><a href="qnetworkcachemetadata.html">QNetworkCacheMetaData</a></span> &<i>metaData</i>)</h3> <p>Returns the device that should be populated with the data for the cache item <i>metaData</i>. When all of the data has been written <a href="qabstractnetworkcache.html#insert">insert</a>() should be called. If <a href="qabstractnetworkcache.html#metaData">metaData</a> is invalid or the url in the metadata is invalid 0 is returned.</p> <p>The cache owns the device and will take care of deleting it when it is inserted or removed.</p> <p>To cancel a prepared inserted call <a href="qabstractnetworkcache.html#remove">remove</a>() on the metadata's url.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#remove">remove</a>(), <a href="qabstractnetworkcache.html#updateMetaData">updateMetaData</a>(), and <a href="qabstractnetworkcache.html#insert">insert</a>().</p> <!-- @@@prepare --> <!-- $$$remove[overload1]$$$removeconstQUrl& --> <h3 class="fn" id="remove"><a name="remove"></a><code>[pure virtual] </code><span class="type">bool</span> QAbstractNetworkCache::<span class="name">remove</span>(const <span class="type"><a href="../qtcore/qurl.html">QUrl</a></span> &<i>url</i>)</h3> <p>Removes the cache entry for <i>url</i>, returning true if success otherwise false.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#clear">clear</a>() and <a href="qabstractnetworkcache.html#prepare">prepare</a>().</p> <!-- @@@remove --> <!-- $$$updateMetaData[overload1]$$$updateMetaDataconstQNetworkCacheMetaData& --> <h3 class="fn" id="updateMetaData"><a name="updateMetaData"></a><code>[pure virtual] </code><span class="type">void</span> QAbstractNetworkCache::<span class="name">updateMetaData</span>(const <span class="type"><a href="qnetworkcachemetadata.html">QNetworkCacheMetaData</a></span> &<i>metaData</i>)</h3> <p>Updates the cache meta date for the <a href="qabstractnetworkcache.html#metaData">metaData</a>'s url to <i>metaData</i></p> <p>If the cache does not contains a cache item for the url then no action is taken.</p> <p>In the base class this is a pure virtual function.</p> <p><b>See also </b><a href="qabstractnetworkcache.html#metaData">metaData</a>() and <a href="qabstractnetworkcache.html#prepare">prepare</a>().</p> <!-- @@@updateMetaData --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>