diff options
| author | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-11-08 12:31:36 -0600 |
|---|---|---|
| committer | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-11-08 12:31:36 -0600 |
| commit | d796c9dd933ab96ec83b9a634feedd5d32e1ba3f (patch) | |
| tree | 6e3dcca4f77e20ec8966c666aac7c35bd4704053 /doc/html/qintcache.html | |
| download | tqt3-d796c9dd933ab96ec83b9a634feedd5d32e1ba3f.tar.gz tqt3-d796c9dd933ab96ec83b9a634feedd5d32e1ba3f.zip | |
Test conversion to TQt3 from Qt3 8c6fc1f8e35fd264dd01c582ca5e7549b32ab731
Diffstat (limited to 'doc/html/qintcache.html')
| -rw-r--r-- | doc/html/qintcache.html | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/doc/html/qintcache.html b/doc/html/qintcache.html new file mode 100644 index 000000000..95e8c634f --- /dev/null +++ b/doc/html/qintcache.html @@ -0,0 +1,242 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/qintcache.doc:41 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>TQIntCache Class</title> +<style type="text/css"><!-- +fn { margin-left: 1cm; text-indent: -1cm; } +a:link { color: #004faf; text-decoration: none } +a:visited { color: #672967; text-decoration: none } +body { background: #ffffff; color: black; } +--></style> +</head> +<body> + +<table border="0" cellpadding="0" cellspacing="0" width="100%"> +<tr bgcolor="#E5E5E5"> +<td valign=center> + <a href="index.html"> +<font color="#004faf">Home</font></a> + | <a href="classes.html"> +<font color="#004faf">All Classes</font></a> + | <a href="mainclasses.html"> +<font color="#004faf">Main Classes</font></a> + | <a href="annotated.html"> +<font color="#004faf">Annotated</font></a> + | <a href="groups.html"> +<font color="#004faf">Grouped Classes</font></a> + | <a href="functions.html"> +<font color="#004faf">Functions</font></a> +</td> +<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQIntCache Class Reference</h1> + +<p>The TQIntCache class is a template class that provides a cache based on long keys. +<a href="#details">More...</a> +<p><tt>#include <<a href="qintcache-h.html">qintcache.h</a>></tt> +<p>Inherits <a href="qptrcollection.html">TQPtrCollection</a>. +<p><a href="qintcache-members.html">List of all member functions.</a> +<h2>Public Members</h2> +<ul> +<li class=fn><a href="#TQIntCache-2"><b>TQIntCache</b></a> ( int maxCost = 100, int size = 17 )</li> +<li class=fn><a href="#~TQIntCache"><b>~TQIntCache</b></a> ()</li> +<li class=fn>int <a href="#maxCost"><b>maxCost</b></a> () const</li> +<li class=fn>int <a href="#totalCost"><b>totalCost</b></a> () const</li> +<li class=fn>void <a href="#setMaxCost"><b>setMaxCost</b></a> ( int m )</li> +<li class=fn>virtual uint <a href="#count"><b>count</b></a> () const</li> +<li class=fn>uint <a href="#size"><b>size</b></a> () const</li> +<li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li> +<li class=fn>bool <a href="#insert"><b>insert</b></a> ( long k, const type * d, int c = 1, int p = 0 )</li> +<li class=fn>bool <a href="#remove"><b>remove</b></a> ( long k )</li> +<li class=fn>type * <a href="#take"><b>take</b></a> ( long k )</li> +<li class=fn>virtual void <a href="#clear"><b>clear</b></a> ()</li> +<li class=fn>type * <a href="#find"><b>find</b></a> ( long k, bool ref = TRUE ) const</li> +<li class=fn>type * <a href="#operator[]"><b>operator[]</b></a> ( long k ) const</li> +<li class=fn>void <a href="#statistics"><b>statistics</b></a> () const</li> +</ul> +<hr><a name="details"></a><h2>Detailed Description</h2> + + +The TQIntCache class is a template class that provides a cache based on long keys. +<p> + +<p> TQIntCache is implemented as a template class. Define a template +instance TQIntCache<X> to create a cache that operates on +pointers to X, or X*. +<p> A cache is a least recently used (LRU) list of cache items, +accessed via <tt>long</tt> keys. Each cache item has a cost. The sum +of item costs, <a href="#totalCost">totalCost</a>(), will not exceed the maximum cache +cost, <a href="#maxCost">maxCost</a>(). If inserting a new item would cause the total +cost to exceed the maximum cost, the least recently used items in +the cache are removed. +<p> Apart from <a href="#insert">insert</a>(), by far the most important function is <a href="#find">find</a>() +(which also exists as operator[]). This function looks up an +item, returns it, and by default marks it as being the most +recently used item. +<p> There are also methods to <a href="#remove">remove</a>() or <a href="#take">take</a>() an object from the +cache. Calling <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(TRUE) for a cache tells it to delete +items that are removed. The default is to not delete items when +they are removed (i.e. remove() and take() are equivalent). +<p> When inserting an item into the cache, only the pointer is copied, +not the item itself. This is called a <a href="shclass.html#shallow-copy">shallow copy</a>. It is possible +to make the cache copy all of the item's data (known as a <a href="shclass.html#deep-copy">deep copy</a>) when an item is inserted. insert() calls the virtual +function <a href="qptrcollection.html#newItem">TQPtrCollection::newItem</a>() for the item to be inserted. +Inherit a dictionary and reimplement <a href="qptrcollection.html#newItem">newItem</a>() if you want deep +copies. +<p> When removing a cache item, the item will be automatically +deleted if auto-deletion is enabled. +<p> There is a <a href="qintcacheiterator.html">TQIntCacheIterator</a> which may be used to traverse the +items in the cache in arbitrary order. +<p> <p>See also <a href="qintcacheiterator.html">TQIntCacheIterator</a>, <a href="qcache.html">TQCache</a>, <a href="qasciicache.html">TQAsciiCache</a>, <a href="collection.html">Collection Classes</a>, and <a href="tools.html">Non-GUI Classes</a>. + +<hr><h2>Member Function Documentation</h2> +<h3 class=fn><a name="TQIntCache-2"></a>TQIntCache::TQIntCache ( int maxCost = 100, int size = 17 ) +</h3> + +<p> Constructs a cache whose contents will never have a total cost +greater than <em>maxCost</em> and which is expected to contain less than +<em>size</em> items. +<p> <em>size</em> is actually the size of an internal hash array; it's +usually best to make it <a href="primes.html#prime">prime</a> and at least 50% bigger than the +largest expected number of items in the cache. +<p> Each inserted item is associated with a cost. When inserting a new +item, if the total cost of all items in the cache will exceed <em>maxCost</em>, the cache will start throwing out the older (least +recently used) items until there is enough room for the new item +to be inserted. + +<h3 class=fn><a name="~TQIntCache"></a>TQIntCache::~TQIntCache () +</h3> + +<p> Removes all items from the cache and then destroys the int cache. +If auto-deletion is enabled the cache's items are deleted. All +iterators that access this cache will be reset. + +<h3 class=fn>void <a name="clear"></a>TQIntCache::clear ()<tt> [virtual]</tt> +</h3> + +<p> Removes all items from the cache, and deletes them if +auto-deletion has been enabled. +<p> All cache iterators that operate this on cache are reset. +<p> <p>See also <a href="#remove">remove</a>() and <a href="#take">take</a>(). + +<p>Reimplemented from <a href="qptrcollection.html#clear">TQPtrCollection</a>. +<h3 class=fn>uint <a name="count"></a>TQIntCache::count () const<tt> [virtual]</tt> +</h3> + +<p> Returns the number of items in the cache. +<p> <p>See also <a href="#totalCost">totalCost</a>(). + +<p>Reimplemented from <a href="qptrcollection.html#count">TQPtrCollection</a>. +<h3 class=fn>type * <a name="find"></a>TQIntCache::find ( long k, bool ref = TRUE ) const +</h3> + +<p> Returns the item associated with <em>k</em>, or 0 if the key does not +exist in the cache. If <em>ref</em> is TRUE (the default), the item is +moved to the front of the least recently used list. +<p> If there are two or more items with equal keys, the one that was +inserted most recently is returned. + +<h3 class=fn>bool <a name="insert"></a>TQIntCache::insert ( long k, const type * d, int c = 1, int p = 0 ) +</h3> + +<p> Inserts the item <em>d</em> into the cache with key <em>k</em> and assigns it +a cost of <em>c</em> (default 1). Returns TRUE if it succeeds; otherwise +returns FALSE. +<p> The cache's size is limited, and if the total cost is too high, +TQIntCache will remove old, least-used items until there is room +for this new item. +<p> The parameter <em>p</em> is internal and should be left at the default +value (0). +<p> <b>Warning:</b> If this function returns FALSE (for example, the cost <tt>,</tt> +exceeds <a href="#maxCost">maxCost</a>()), you must delete <em>d</em> yourself. Additionally, +be very careful about using <em>d</em> after calling this function. Any +other insertions into the cache, from anywhere in the application +or within TQt itself, could cause the object to be discarded from +the cache and the pointer to become invalid. + +<h3 class=fn>bool <a name="isEmpty"></a>TQIntCache::isEmpty () const +</h3> + +<p> Returns TRUE if the cache is empty; otherwise returns FALSE. + +<h3 class=fn>int <a name="maxCost"></a>TQIntCache::maxCost () const +</h3> + +<p> Returns the maximum allowed total cost of the cache. +<p> <p>See also <a href="#setMaxCost">setMaxCost</a>() and <a href="#totalCost">totalCost</a>(). + +<h3 class=fn>type * <a name="operator[]"></a>TQIntCache::operator[] ( long k ) const +</h3> + +<p> Returns the item associated with <em>k</em>, or 0 if <em>k</em> does not exist +in the cache, and moves the item to the front of the least +recently used list. +<p> If there are two or more items with equal keys, the one that was +inserted most recently is returned. +<p> This is the same as <a href="#find">find</a>( k, TRUE ). +<p> <p>See also <a href="#find">find</a>(). + +<h3 class=fn>bool <a name="remove"></a>TQIntCache::remove ( long k ) +</h3> + +<p> Removes the item associated with <em>k</em>, and returns TRUE if the +item was present in the cache; otherwise returns FALSE. +<p> The item is deleted if auto-deletion has been enabled, i.e. if you +have called <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(TRUE). +<p> If there are two or more items with equal keys, the one that was +inserted most recently is removed. +<p> All iterators that refer to the removed item are set to point to +the next item in the cache's traversal order. +<p> <p>See also <a href="#take">take</a>() and <a href="#clear">clear</a>(). + +<h3 class=fn>void <a name="setMaxCost"></a>TQIntCache::setMaxCost ( int m ) +</h3> + +<p> Sets the maximum allowed total cost of the cache to <em>m</em>. If the +current total cost is greater than <em>m</em>, some items are removed +immediately. +<p> <p>See also <a href="#maxCost">maxCost</a>() and <a href="#totalCost">totalCost</a>(). + +<h3 class=fn>uint <a name="size"></a>TQIntCache::size () const +</h3> + +<p> Returns the size of the hash array used to implement the cache. +This should be a bit larger than <a href="#count">count</a>() is likely to be. + +<h3 class=fn>void <a name="statistics"></a>TQIntCache::statistics () const +</h3> + +<p> A debug-only utility function. Prints out cache usage, hit/miss, +and distribution information using <a href="qapplication.html#qDebug">qDebug</a>(). This function does +nothing in the release library. + +<h3 class=fn>type * <a name="take"></a>TQIntCache::take ( long k ) +</h3> + +<p> Takes the item associated with <em>k</em> out of the cache without +deleting it, and returns a pointer to the item taken out or 0 if +the key does not exist in the cache. +<p> If there are two or more items with equal keys, the one that was +inserted most recently is taken. +<p> All iterators that refer to the taken item are set to point to the +next item in the cache's traversal order. +<p> <p>See also <a href="#remove">remove</a>() and <a href="#clear">clear</a>(). + +<h3 class=fn>int <a name="totalCost"></a>TQIntCache::totalCost () const +</h3> + +<p> Returns the total cost of the items in the cache. This is an +integer in the range 0 to <a href="#maxCost">maxCost</a>(). +<p> <p>See also <a href="#setMaxCost">setMaxCost</a>(). + +<!-- eof --> +<hr><p> +This file is part of the <a href="index.html">TQt toolkit</a>. +Copyright © 1995-2007 +<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center> +<table width=100% cellspacing=0 border=0><tr> +<td>Copyright © 2007 +<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> +<td align=right><div align=right>TQt 3.3.8</div> +</table></div></address></body> +</html> |