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diff --git a/www/c3ref/get_clientdata.html b/www/c3ref/get_clientdata.html new file mode 100644 index 0000000..9179dd1 --- /dev/null +++ b/www/c3ref/get_clientdata.html @@ -0,0 +1,180 @@ +<!DOCTYPE html> +<html><head> +<meta name="viewport" content="width=device-width, initial-scale=1.0"> +<meta http-equiv="content-type" content="text/html; charset=UTF-8"> +<link href="../sqlite.css" rel="stylesheet"> +<title>Database Connection Client Data</title> +<!-- path=../ --> +</head> +<body> +<div class=nosearch> +<a href="../index.html"> +<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0"> +</a> +<div><!-- IE hack to prevent disappearing logo --></div> +<div class="tagline desktoponly"> +Small. Fast. Reliable.<br>Choose any three. +</div> +<div class="menu mainmenu"> +<ul> +<li><a href="../index.html">Home</a> +<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a> +<li class='wideonly'><a href='../about.html'>About</a> +<li class='desktoponly'><a href="../docs.html">Documentation</a> +<li class='desktoponly'><a href="../download.html">Download</a> +<li class='wideonly'><a href='../copyright.html'>License</a> +<li class='desktoponly'><a href="../support.html">Support</a> +<li class='desktoponly'><a href="../prosupport.html">Purchase</a> +<li class='search' id='search_menubutton'> +<a href="javascript:void(0)" onclick='toggle_search()'>Search</a> +</ul> +</div> +<div class="menu submenu" id="submenu"> +<ul> +<li><a href='../about.html'>About</a> +<li><a href='../docs.html'>Documentation</a> +<li><a href='../download.html'>Download</a> +<li><a href='../support.html'>Support</a> +<li><a href='../prosupport.html'>Purchase</a> +</ul> +</div> +<div class="searchmenu" id="searchmenu"> +<form method="GET" action="../search"> +<select name="s" id="searchtype"> +<option value="d">Search Documentation</option> +<option value="c">Search Changelog</option> +</select> +<input type="text" name="q" id="searchbox" value=""> +<input type="submit" value="Go"> +</form> +</div> +</div> +<script> +function toggle_div(nm) { +var w = document.getElementById(nm); +if( w.style.display=="block" ){ +w.style.display = "none"; +}else{ +w.style.display = "block"; +} +} +function toggle_search() { +var w = document.getElementById("searchmenu"); +if( w.style.display=="block" ){ +w.style.display = "none"; +} else { +w.style.display = "block"; +setTimeout(function(){ +document.getElementById("searchbox").focus() +}, 30); +} +} +function div_off(nm){document.getElementById(nm).style.display="none";} +window.onbeforeunload = function(e){div_off("submenu");} +/* Disable the Search feature if we are not operating from CGI, since */ +/* Search is accomplished using CGI and will not work without it. */ +if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){ +document.getElementById("search_menubutton").style.display = "none"; +} +/* Used by the Hide/Show button beside syntax diagrams, to toggle the */ +function hideorshow(btn,obj){ +var x = document.getElementById(obj); +var b = document.getElementById(btn); +if( x.style.display!='none' ){ +x.style.display = 'none'; +b.innerHTML='show'; +}else{ +x.style.display = ''; +b.innerHTML='hide'; +} +return false; +} +var antiRobot = 0; +function antiRobotGo(){ +if( antiRobot!=3 ) return; +antiRobot = 7; +var j = document.getElementById("mtimelink"); +if(j && j.hasAttribute("data-href")) j.href=j.getAttribute("data-href"); +} +function antiRobotDefense(){ +document.body.onmousedown=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousedown=null; +} +document.body.onmousemove=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousemove=null; +} +setTimeout(function(){ +antiRobot |= 1; +antiRobotGo(); +}, 100) +antiRobotGo(); +} +antiRobotDefense(); +</script> +<!-- keywords: sqlite3_get_clientdata sqlite3_set_clientdata --> +<div class=nosearch> +<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a> +<h2>Database Connection Client Data</h2> +</div> +<blockquote><pre> +void *sqlite3_get_clientdata(sqlite3*,const char*); +int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); +</pre></blockquote> +<p> +These functions are used to associate one or more named pointers +with a <a href="../c3ref/sqlite3.html">database connection</a>. +A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P +to be attached to <a href="../c3ref/sqlite3.html">database connection</a> D using name N. Subsequent +calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P +or a NULL pointer if there were no prior calls to +sqlite3_set_clientdata() with the same values of D and N. +Names are compared using strcmp() and are thus case sensitive.</p> + +<p>If P and X are both non-NULL, then the destructor X is invoked with +argument P on the first of the following occurrences: +<ul> +<li> An out-of-memory error occurs during the call to +sqlite3_set_clientdata() which attempts to register pointer P. +<li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made +with the same D and N parameters. +<li> The database connection closes. SQLite does not make any guarantees +about the order in which destructors are called, only that all +destructors will be called exactly once at some point during the +database connection closing process. +</ul></p> + +<p>SQLite does not do anything with client data other than invoke +destructors on the client data at the appropriate time. The intended +use for client data is to provide a mechanism for wrapper libraries +to store additional information about an SQLite database connection.</p> + +<p>There is no limit (other than available memory) on the number of different +client data pointers (with different names) that can be attached to a +single database connection. However, the implementation is optimized +for the case of having only one or two different client data names. +Applications and wrapper libraries are discouraged from using more than +one client data name each.</p> + +<p>There is no way to enumerate the client data pointers +associated with a database connection. The N parameter can be thought +of as a secret key such that only code that knows the secret key is able +to access the associated data.</p> + +<p>Security Warning: These interfaces should not be exposed in scripting +languages or in other circumstances where it might be possible for an +an attacker to invoke them. Any agent that can invoke these interfaces +can probably also take control of the process.</p> + +<p>Database connection client data is only available for SQLite +version 3.44.0 (2023-11-01) and later.</p> + +<p>See also: <a href="../c3ref/get_auxdata.html">sqlite3_set_auxdata()</a> and <a href="../c3ref/get_auxdata.html">sqlite3_get_auxdata()</a>. +</p><p>See also lists of + <a href="../c3ref/objlist.html">Objects</a>, + <a href="../c3ref/constlist.html">Constants</a>, and + <a href="../c3ref/funclist.html">Functions</a>.</p> + |