| <!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 (1.8.0_121) on Wed Mar 29 10:00:26 PDT 2017 --> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <title>com.yahoo.memory (com.yahoo.datasketches:memory 0.9.9-SNAPSHOT API)</title> |
| <meta name="date" content="2017-03-29"> |
| <link rel="stylesheet" type="text/css" href="../../../stylesheet.css" title="Style"> |
| <script type="text/javascript" src="../../../script.js"></script> |
| </head> |
| <body> |
| <script type="text/javascript"><!-- |
| try { |
| if (location.href.indexOf('is-external=true') == -1) { |
| parent.document.title="com.yahoo.memory (com.yahoo.datasketches:memory 0.9.9-SNAPSHOT API)"; |
| } |
| } |
| catch(err) { |
| } |
| //--> |
| </script> |
| <noscript> |
| <div>JavaScript is disabled on your browser.</div> |
| </noscript> |
| <!-- ========= START OF TOP NAVBAR ======= --> |
| <div class="topNav"><a name="navbar.top"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.top" title="Skip navigation links">Skip navigation links</a></div> |
| <a name="navbar.top.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../overview-summary.html">Overview</a></li> |
| <li><a href="../../../com/yahoo/memory/package-summary.html">Package</a></li> |
| <li>Class</li> |
| <li><a href="package-use.html">Use</a></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>Prev Package</li> |
| <li>Next Package</li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../index.html?com/yahoo/memory/package-summary.html" target="_top">Frames</a></li> |
| <li><a href="package-summary.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> |
| <a name="skip.navbar.top"> |
| <!-- --> |
| </a></div> |
| <!-- ========= END OF TOP NAVBAR ========= --> |
| <div class="header"> |
| <h1 title="Package" class="title">Package com.yahoo.memory</h1> |
| <div class="docSummary"> |
| <div class="block">The goal of this package is to provide high performance access to native memory for primitives |
| and primitive arrays.</div> |
| </div> |
| <p>See: <a href="#package.description">Description</a></p> |
| </div> |
| <div class="contentContainer"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <table class="typeSummary" border="0" cellpadding="3" cellspacing="0" summary="Interface Summary table, listing interfaces, and an explanation"> |
| <caption><span>Interface Summary</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Interface</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/MemoryRequest.html" title="interface in com.yahoo.memory">MemoryRequest</a></td> |
| <td class="colLast"> |
| <div class="block">The MemoryRequest is a callback interface provides a means for a WritableMemory object to |
| request more memory from the WritableMemoryDirectHandler.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </li> |
| <li class="blockList"> |
| <table class="typeSummary" border="0" cellpadding="3" cellspacing="0" summary="Class Summary table, listing classes, and an explanation"> |
| <caption><span>Class Summary</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Class</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/Buffer.html" title="class in com.yahoo.memory">Buffer</a></td> |
| <td class="colLast"> |
| <div class="block">Provides read-only, positional primitive and primitive array methods to any of the four resources |
| mentioned in the package level documentation.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/Memory.html" title="class in com.yahoo.memory">Memory</a></td> |
| <td class="colLast"> |
| <div class="block">Provides read-only primitive and primitive array methods to any of the four resources |
| mentioned in the package level documentation.</div> |
| </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/MemoryMapHandler.html" title="class in com.yahoo.memory">MemoryMapHandler</a></td> |
| <td class="colLast"> |
| <div class="block">Gets a Memory for a memory-mapped, read-only file resource, It is highly recommended that this be created inside a |
| <i>try-with-resources</i> statement.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/UnsafeUtil.html" title="class in com.yahoo.memory">UnsafeUtil</a></td> |
| <td class="colLast"> |
| <div class="block">Provides access to the sun.misc.Unsafe class and its key static fields.</div> |
| </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/WritableBuffer.html" title="class in com.yahoo.memory">WritableBuffer</a></td> |
| <td class="colLast"> |
| <div class="block">Provides read and write, positional primitive and primitive array access to any of the four |
| resources mentioned at the package level.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/WritableMemory.html" title="class in com.yahoo.memory">WritableMemory</a></td> |
| <td class="colLast"> |
| <div class="block">Provides read and write primitive and primitive array access to any of the four resources |
| mentioned at the package level.</div> |
| </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/WritableMemoryDirectHandler.html" title="class in com.yahoo.memory">WritableMemoryDirectHandler</a></td> |
| <td class="colLast"> |
| <div class="block">Gets a WritableMemory for a writable direct memory resource.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/WritableMemoryMapHandler.html" title="class in com.yahoo.memory">WritableMemoryMapHandler</a></td> |
| <td class="colLast"> |
| <div class="block">Gets a WritableMemory for a writable memory-mapped file resource.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </li> |
| <li class="blockList"> |
| <table class="typeSummary" border="0" cellpadding="3" cellspacing="0" summary="Exception Summary table, listing exceptions, and an explanation"> |
| <caption><span>Exception Summary</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Exception</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="../../../com/yahoo/memory/ReadOnlyException.html" title="class in com.yahoo.memory">ReadOnlyException</a></td> |
| <td class="colLast"> |
| <div class="block">The exception thrown when attempting to write into a read-only Resource.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </li> |
| </ul> |
| <a name="package.description"> |
| <!-- --> |
| </a> |
| <h2 title="Package com.yahoo.memory Description">Package com.yahoo.memory Description</h2> |
| <div class="block">The goal of this package is to provide high performance access to native memory for primitives |
| and primitive arrays. It also provides consistent views into heap-based arrays, |
| Java ByteBuffers and memory mapped files. This package is general purpose, has no external |
| dependencies and can be used in any application that needs to manage data structures outside |
| the Java heap. |
| |
| <p>More specifically, this package provides access to four different types of resources using |
| the same API: |
| <ul><li>Native (or Direct) Memory allocated by the user.</li> |
| <li><code>ByteBuffers</code>, both heap-based and direct, writable and read-only.</li> |
| <li>Memory-mapped files, both writable and read-only.</li> |
| <li>Heap-based primitive arrays</li> |
| </ul> |
| |
| The features of this design are as follows: |
| <ul><li>The writable and read-only APIs are separated to make them compile time detectable.</li> |
| |
| <li>Converting a writable instance into a read-only instance is a simple up-cast. |
| For example: <pre><code> |
| WritableMemory wMem = ... |
| Memory mem = wMem; |
| </code></pre> |
| </li> |
| |
| <li>The native memory and the memory mapped file resources implement <code>AutoCloseable</code> so |
| that these resources are automatically closed if wrapped in a try-with-resources (TRW) block. |
| These resources are acquired using simple handlers that implement the <code>close()</code> |
| method: <pre><code> |
| try (WritableMemoryMapHandler handler = WritableResource.map(File file)) { |
| WritableMemory wMem = handler.get(); |
| // read and write to memory mapped file. |
| } |
| </code></pre> |
| Where it is desirable to pass ownership of the resource (and the <code>close()</code> responsibility) |
| one can not use the TWR block. Instead:<pre><code> |
| WritableMemoryMapHandler handler = WritableResource.map(File file); |
| ... |
| doWorkAndClose(handler); //passes the handler to downstream object that closes the resource. |
| </code></pre> |
| </li> |
| |
| <li>This package offers both a direct offset access API (<i>Memory</i>) and a positional API |
| (<i>Buffer</i>). Moving back and forth between these two views of the same resource is simple: |
| <pre><code> |
| Memory mem = ... |
| Buffer buf = mem.asBuffer(); |
| ... |
| Memory mem2 = buf.asMemory(); |
| ... |
| </code></pre> |
| </li> |
| |
| <li>With asserts enabled in the JVM, all methods are checked for bounds and |
| use-after-close violations.</li> |
| |
| <li>Hierarchical memory regions can be easily created:<pre><code> |
| WritableMemory wMem = ... |
| WritableMemory wReg = wMem.writableRegion(offset, length); //OR |
| Memory reg = wMem.region(offset, length); |
| </code></pre> |
| </li> |
| </ul></div> |
| <dl> |
| <dt><span class="simpleTagLabel">Author:</span></dt> |
| <dd>Lee Rhodes</dd> |
| </dl> |
| </div> |
| <!-- ======= START OF BOTTOM NAVBAR ====== --> |
| <div class="bottomNav"><a name="navbar.bottom"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.bottom" title="Skip navigation links">Skip navigation links</a></div> |
| <a name="navbar.bottom.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../overview-summary.html">Overview</a></li> |
| <li><a href="../../../com/yahoo/memory/package-summary.html">Package</a></li> |
| <li>Class</li> |
| <li><a href="package-use.html">Use</a></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>Prev Package</li> |
| <li>Next Package</li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../index.html?com/yahoo/memory/package-summary.html" target="_top">Frames</a></li> |
| <li><a href="package-summary.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> |
| <a name="skip.navbar.bottom"> |
| <!-- --> |
| </a></div> |
| <!-- ======== END OF BOTTOM NAVBAR ======= --> |
| <p class="legalCopy"><small>Copyright © 2015–2017 <a href="https://www.yahoo.com">Yahoo! Inc.</a>. All rights reserved.</small></p> |
| </body> |
| </html> |
