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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!-- NewPage --> <html lang="en"> <head> <!-- Generated by javadoc (version 1.7.0_91) on Thu Jan 14 10:04:48 GMT 2016 --> <title>IntAllocator</title> <meta name="date" content="2016-01-14"> <link rel="stylesheet" type="text/css" href="../../../stylesheet.css" title="Style"> </head> <body> <script type="text/javascript"><!-- if (location.href.indexOf('is-external=true') == -1) { parent.document.title="IntAllocator"; } //--> </script> <noscript> <div>JavaScript is disabled on your browser.</div> </noscript> <!-- ========= START OF TOP NAVBAR ======= --> <div class="topNav"><a name="navbar_top"> <!-- --> </a><a href="#skip-navbar_top" title="Skip navigation links"></a><a name="navbar_top_firstrow"> <!-- --> </a> <ul class="navList" title="Navigation"> <li><a href="../../../overview-summary.html">Overview</a></li> <li><a href="package-summary.html">Package</a></li> <li class="navBarCell1Rev">Class</li> <li><a href="package-tree.html">Tree</a></li> <li><a href="../../../deprecated-list.html">Deprecated</a></li> <li><a href="../../../index-all.html">Index</a></li> <li><a href="../../../help-doc.html">Help</a></li> </ul> </div> <div class="subNav"> <ul class="navList"> <li><a href="../../../com/rabbitmq/utility/BlockingValueOrException.html" title="class in com.rabbitmq.utility"><span class="strong">Prev Class</span></a></li> <li><a href="../../../com/rabbitmq/utility/SensibleClone.html" title="interface in com.rabbitmq.utility"><span class="strong">Next Class</span></a></li> </ul> <ul class="navList"> <li><a href="../../../index.html?com/rabbitmq/utility/IntAllocator.html" target="_top">Frames</a></li> <li><a href="IntAllocator.html" target="_top">No Frames</a></li> </ul> <ul class="navList" id="allclasses_navbar_top"> <li><a href="../../../allclasses-noframe.html">All Classes</a></li> </ul> <div> <script type="text/javascript"><!-- allClassesLink = document.getElementById("allclasses_navbar_top"); if(window==top) { allClassesLink.style.display = "block"; } else { allClassesLink.style.display = "none"; } //--> </script> </div> <div> <ul class="subNavList"> <li>Summary: </li> <li>Nested | </li> <li>Field | </li> <li><a href="#constructor_summary">Constr</a> | </li> <li><a href="#method_summary">Method</a></li> </ul> <ul class="subNavList"> <li>Detail: </li> <li>Field | </li> <li><a href="#constructor_detail">Constr</a> | </li> <li><a href="#method_detail">Method</a></li> </ul> </div> <a name="skip-navbar_top"> <!-- --> </a></div> <!-- ========= END OF TOP NAVBAR ========= --> <!-- ======== START OF CLASS DATA ======== --> <div class="header"> <div class="subTitle">com.rabbitmq.utility</div> <h2 title="Class IntAllocator" class="title">Class IntAllocator</h2> </div> <div class="contentContainer"> <ul class="inheritance"> <li>java.lang.Object</li> <li> <ul class="inheritance"> <li>com.rabbitmq.utility.IntAllocator</li> </ul> </li> </ul> <div class="description"> <ul class="blockList"> <li class="blockList"> <hr> <br> <pre>public class <span class="strong">IntAllocator</span> extends java.lang.Object</pre> <div class="block">A class for allocating integers from a given range that uses a <code>BitSet</code> representation of the free integers. <p/><strong>Concurrent Semantics:</strong><br /> This class is <b><i>not</i></b> thread safe. <p/><b>Implementation notes:</b> <br/>This was originally an ordered chain of non-overlapping Intervals, together with a fixed size array cache for freed integers. <br/><a href="../../../com/rabbitmq/utility/IntAllocator.html#reserve(int)"><code>reserve(int)</code></a> was expensive in this scheme, whereas in the present implementation it is O(1), as is <a href="../../../com/rabbitmq/utility/IntAllocator.html#free(int)"><code>free(int)</code></a>. <p>Although <a href="../../../com/rabbitmq/utility/IntAllocator.html#allocate()"><code>allocate()</code></a> is slightly slower than O(1) and in the worst case could be O(N), the use of a "<code>lastIndex</code>" field for starting the next scan for free integers means this is negligible. </p> <p>The data representation overhead is O(N) where N is the size of the allocation range. One <code>long</code> is used for every 64 integers in the range. </p> <p>Very little Object creation and destruction occurs in use.</p></div> </li> </ul> </div> <div class="summary"> <ul class="blockList"> <li class="blockList"> <!-- ======== CONSTRUCTOR SUMMARY ======== --> <ul class="blockList"> <li class="blockList"><a name="constructor_summary"> <!-- --> </a> <h3>Constructor Summary</h3> <table class="overviewSummary" border="0" cellpadding="3" cellspacing="0" summary="Constructor Summary table, listing constructors, and an explanation"> <caption><span>Constructors</span><span class="tabEnd"> </span></caption> <tr> <th class="colOne" scope="col">Constructor and Description</th> </tr> <tr class="altColor"> <td class="colOne"><code><strong><a href="../../../com/rabbitmq/utility/IntAllocator.html#IntAllocator(int,%20int)">IntAllocator</a></strong>(int bottom, int top)</code> <div class="block">Creates an IntAllocator allocating integer IDs within the inclusive range [<code>bottom</code>, <code>top</code>].</div> </td> </tr> </table> </li> </ul> <!-- ========== METHOD SUMMARY =========== --> <ul class="blockList"> <li class="blockList"><a name="method_summary"> <!-- --> </a> <h3>Method Summary</h3> <table class="overviewSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation"> <caption><span>Methods</span><span class="tabEnd"> </span></caption> <tr> <th class="colFirst" scope="col">Modifier and Type</th> <th class="colLast" scope="col">Method and Description</th> </tr> <tr class="altColor"> <td class="colFirst"><code>int</code></td> <td class="colLast"><code><strong><a href="../../../com/rabbitmq/utility/IntAllocator.html#allocate()">allocate</a></strong>()</code> <div class="block">Allocate an unallocated integer from the range, or return -1 if no more integers are available.</div> </td> </tr> <tr class="rowColor"> <td class="colFirst"><code>void</code></td> <td class="colLast"><code><strong><a href="../../../com/rabbitmq/utility/IntAllocator.html#free(int)">free</a></strong>(int reservation)</code> <div class="block">Make the provided integer available for allocation again.</div> </td> </tr> <tr class="altColor"> <td class="colFirst"><code>boolean</code></td> <td class="colLast"><code><strong><a href="../../../com/rabbitmq/utility/IntAllocator.html#reserve(int)">reserve</a></strong>(int reservation)</code> <div class="block">Attempt to reserve the provided ID as if it had been allocated.</div> </td> </tr> <tr class="rowColor"> <td class="colFirst"><code>java.lang.String</code></td> <td class="colLast"><code><strong><a href="../../../com/rabbitmq/utility/IntAllocator.html#toString()">toString</a></strong>()</code> </td> </tr> </table> <ul class="blockList"> <li class="blockList"><a name="methods_inherited_from_class_java.lang.Object"> <!-- --> </a> <h3>Methods inherited from class java.lang.Object</h3> <code>clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait</code></li> </ul> </li> </ul> </li> </ul> </div> <div class="details"> <ul class="blockList"> <li class="blockList"> <!-- ========= CONSTRUCTOR DETAIL ======== --> <ul class="blockList"> <li class="blockList"><a name="constructor_detail"> <!-- --> </a> <h3>Constructor Detail</h3> <a name="IntAllocator(int, int)"> <!-- --> </a> <ul class="blockListLast"> <li class="blockList"> <h4>IntAllocator</h4> <pre>public IntAllocator(int bottom, int top)</pre> <div class="block">Creates an IntAllocator allocating integer IDs within the inclusive range [<code>bottom</code>, <code>top</code>].</div> <dl><dt><span class="strong">Parameters:</span></dt><dd><code>bottom</code> - lower end of range</dd><dd><code>top</code> - upper end of range (inclusive)</dd></dl> </li> </ul> </li> </ul> <!-- ============ METHOD DETAIL ========== --> <ul class="blockList"> <li class="blockList"><a name="method_detail"> <!-- --> </a> <h3>Method Detail</h3> <a name="allocate()"> <!-- --> </a> <ul class="blockList"> <li class="blockList"> <h4>allocate</h4> <pre>public int allocate()</pre> <div class="block">Allocate an unallocated integer from the range, or return -1 if no more integers are available.</div> <dl><dt><span class="strong">Returns:</span></dt><dd>the allocated integer, or -1</dd></dl> </li> </ul> <a name="free(int)"> <!-- --> </a> <ul class="blockList"> <li class="blockList"> <h4>free</h4> <pre>public void free(int reservation)</pre> <div class="block">Make the provided integer available for allocation again. This operation runs in O(1) time. <br/>No error checking is performed, so if you double free or free an integer that was not originally allocated the results are undefined.</div> <dl><dt><span class="strong">Parameters:</span></dt><dd><code>reservation</code> - the previously allocated integer to free</dd></dl> </li> </ul> <a name="reserve(int)"> <!-- --> </a> <ul class="blockList"> <li class="blockList"> <h4>reserve</h4> <pre>public boolean reserve(int reservation)</pre> <div class="block">Attempt to reserve the provided ID as if it had been allocated. Returns true if it is available, false otherwise. <br/> This operation runs in O(1) time.</div> <dl><dt><span class="strong">Parameters:</span></dt><dd><code>reservation</code> - the integer to be allocated, if possible</dd> <dt><span class="strong">Returns:</span></dt><dd><code><b>true</b></code> if allocated, <code><b>false</b></code> if already allocated</dd></dl> </li> </ul> <a name="toString()"> <!-- --> </a> <ul class="blockListLast"> <li class="blockList"> <h4>toString</h4> <pre>public java.lang.String toString()</pre> <dl> <dt><strong>Overrides:</strong></dt> <dd><code>toString</code> in class <code>java.lang.Object</code></dd> </dl> </li> </ul> </li> </ul> </li> </ul> </div> </div> <!-- ========= END OF CLASS DATA ========= --> <!-- ======= START OF BOTTOM NAVBAR ====== --> <div class="bottomNav"><a name="navbar_bottom"> <!-- --> </a><a href="#skip-navbar_bottom" title="Skip navigation links"></a><a name="navbar_bottom_firstrow"> <!-- --> </a> <ul class="navList" title="Navigation"> <li><a href="../../../overview-summary.html">Overview</a></li> <li><a href="package-summary.html">Package</a></li> <li class="navBarCell1Rev">Class</li> <li><a href="package-tree.html">Tree</a></li> <li><a href="../../../deprecated-list.html">Deprecated</a></li> <li><a href="../../../index-all.html">Index</a></li> <li><a href="../../../help-doc.html">Help</a></li> </ul> </div> <div class="subNav"> <ul class="navList"> <li><a href="../../../com/rabbitmq/utility/BlockingValueOrException.html" title="class in com.rabbitmq.utility"><span class="strong">Prev Class</span></a></li> <li><a href="../../../com/rabbitmq/utility/SensibleClone.html" title="interface in com.rabbitmq.utility"><span class="strong">Next Class</span></a></li> </ul> <ul class="navList"> <li><a href="../../../index.html?com/rabbitmq/utility/IntAllocator.html" target="_top">Frames</a></li> <li><a href="IntAllocator.html" target="_top">No Frames</a></li> </ul> <ul class="navList" id="allclasses_navbar_bottom"> <li><a href="../../../allclasses-noframe.html">All Classes</a></li> </ul> <div> <script type="text/javascript"><!-- allClassesLink = document.getElementById("allclasses_navbar_bottom"); if(window==top) { allClassesLink.style.display = "block"; } else { allClassesLink.style.display = "none"; } //--> </script> </div> <div> <ul class="subNavList"> <li>Summary: </li> <li>Nested | </li> <li>Field | </li> <li><a href="#constructor_summary">Constr</a> | </li> <li><a href="#method_summary">Method</a></li> </ul> <ul class="subNavList"> <li>Detail: </li> <li>Field | </li> <li><a href="#constructor_detail">Constr</a> | </li> <li><a href="#method_detail">Method</a></li> </ul> </div> <a name="skip-navbar_bottom"> <!-- --> </a></div> <!-- ======== END OF BOTTOM NAVBAR ======= --> </body> </html>