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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="content-type" content="text/html; charset=UTF-8" /><title>RecyclingFastBufferedOutputStream xref</title><link type="text/css" rel="stylesheet" href="../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../apidocs/org/archive/io/RecyclingFastBufferedOutputStream.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> RecyclingFastBufferedOutputStream</em></em><a name="2" href="#2">2</a> <em class="comment">*</em><a name="3" href="#3">3</a> <em class="comment">* $Id: RecyclingFastBufferedOutputStream.java,v 1.1 2005/06/06 20:56:24 gojomo Exp $</em><a name="4" href="#4">4</a> <em class="comment">*</em><a name="5" href="#5">5</a> <em class="comment">* Created on May 26, 2005</em><a name="6" href="#6">6</a> <em class="comment">*</em><a name="7" href="#7">7</a> <em class="comment">* Based on FastBufferedOutputStream in MG4J; see:</em><a name="8" href="#8">8</a> <em class="comment">* </em><a name="9" href="#9">9</a> <em class="comment">* <a href="http://mg4j.dsi.unimi.it/" target="alexandria_uri">http://mg4j.dsi.unimi.it/</a></em><a name="10" href="#10">10</a> <em class="comment">* </em><a name="11" href="#11">11</a> <em class="comment">* (Sole addition is one new constructor.)</em><a name="12" href="#12">12</a> <em class="comment">* </em><a name="13" href="#13">13</a> <em class="comment">* Revisions copyright (C) 2005 Internet Archive.</em><a name="14" href="#14">14</a> <em class="comment">*</em><a name="15" href="#15">15</a> <em class="comment">* This file is part of the Heritrix web crawler (crawler.archive.org).</em><a name="16" href="#16">16</a> <em class="comment">*</em><a name="17" href="#17">17</a> <em class="comment">* Heritrix is free software; you can redistribute it and/or modify</em><a name="18" href="#18">18</a> <em class="comment">* it under the terms of the GNU Lesser Public License as published by</em><a name="19" href="#19">19</a> <em class="comment">* the Free Software Foundation; either version 2.1 of the License, or</em><a name="20" href="#20">20</a> <em class="comment">* any later version.</em><a name="21" href="#21">21</a> <em class="comment">*</em><a name="22" href="#22">22</a> <em class="comment">* Heritrix is distributed in the hope that it will be useful,</em><a name="23" href="#23">23</a> <em class="comment">* but WITHOUT ANY WARRANTY; without even the implied warranty of</em><a name="24" href="#24">24</a> <em class="comment">* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</em><a name="25" href="#25">25</a> <em class="comment">* GNU Lesser Public License for more details.</em><a name="26" href="#26">26</a> <em class="comment">*</em><a name="27" href="#27">27</a> <em class="comment">* You should have received a copy of the GNU Lesser Public License</em><a name="28" href="#28">28</a> <em class="comment">* along with Heritrix; if not, write to the Free Software</em><a name="29" href="#29">29</a> <em class="comment">* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA</em><a name="30" href="#30">30</a> <em class="comment">*/</em> <a name="31" href="#31">31</a> <strong>package</strong> <a href="../../../org/archive/io/package-summary.html">org.archive.io</a>;<a name="32" href="#32">32</a> <a name="33" href="#33">33</a> <strong>import</strong> java.io.IOException;<a name="34" href="#34">34</a> <strong>import</strong> java.io.OutputStream;<a name="35" href="#35">35</a> <a name="36" href="#36">36</a> <em>/**<em>* Lightweight, unsynchronised, aligned output stream buffering class.</em></em><a name="37" href="#37">37</a> <em> *</em><a name="38" href="#38">38</a> <em> * <P>This class provides buffering for output streams, but it does so with </em><a name="39" href="#39">39</a> <em> * purposes and an internal logic that are radically different from the ones</em><a name="40" href="#40">40</a> <em> * adopted in {@link java.io.BufferedOutputStream}.</em><a name="41" href="#41">41</a> <em> * </em><a name="42" href="#42">42</a> <em> * <P>All methods are unsychronised. Moreover,</em><a name="43" href="#43">43</a> <em> * it is guaranteed that <em>all writes performed by this class will be</em><a name="44" href="#44">44</a> <em> * multiples of the given buffer size</em>. If, for instance, you use the</em><a name="45" href="#45">45</a> <em> * default buffer size, writes will be performed on the underlying input stream</em><a name="46" href="#46">46</a> <em> * in multiples of 16384 bytes. This is very important on operating systems</em><a name="47" href="#47">47</a> <em> * that optimise disk reads on disk block boundaries.</em><a name="48" href="#48">48</a> <em> */</em><a name="49" href="#49">49</a> <a name="50" href="#50">50</a> <strong>public</strong> <strong>class</strong> <a href="../../../org/archive/io/RecyclingFastBufferedOutputStream.html">RecyclingFastBufferedOutputStream</a> <strong>extends</strong> OutputStream {<a name="51" href="#51">51</a> <a name="52" href="#52">52</a> <em>/**<em>* The default size of the internal buffer in bytes (16Ki). */</em></em><a name="53" href="#53">53</a> <strong>public</strong> <strong>final</strong> <strong>static</strong> <strong>int</strong> DEFAULT_BUFFER_SIZE = 16 * 1024;<a name="54" href="#54">54</a> <a name="55" href="#55">55</a> <em>/**<em>* The internal buffer. */</em></em><a name="56" href="#56">56</a> <strong>protected</strong> byte buffer[];<a name="57" href="#57">57</a> <a name="58" href="#58">58</a> <em>/**<em>* The current position in the buffer. */</em></em><a name="59" href="#59">59</a> <strong>protected</strong> <strong>int</strong> pos;<a name="60" href="#60">60</a> <a name="61" href="#61">61</a> <em>/**<em>* The number of buffer bytes available starting from {@link #pos}. */</em></em><a name="62" href="#62">62</a> <strong>protected</strong> <strong>int</strong> avail;<a name="63" href="#63">63</a> <a name="64" href="#64">64</a> <em>/**<em>* The underlying output stream. */</em></em><a name="65" href="#65">65</a> <strong>protected</strong> OutputStream os;<a name="66" href="#66">66</a> <a name="67" href="#67">67</a> <em>/**<em>* Creates a new fast buffered output stream by wrapping a given output stream, using a given buffer </em></em><a name="68" href="#68">68</a> <em> *</em><a name="69" href="#69">69</a> <em> * @param os an output stream to wrap.</em><a name="70" href="#70">70</a> <em> * @param buffer buffer to use internally.</em><a name="71" href="#71">71</a> <em> */</em><a name="72" href="#72">72</a> <a name="73" href="#73">73</a> <strong>public</strong> <a href="../../../org/archive/io/RecyclingFastBufferedOutputStream.html">RecyclingFastBufferedOutputStream</a>( <strong>final</strong> OutputStream os, <strong>final</strong> byte[] buffer ) {<a name="74" href="#74">74</a> <strong>this</strong>.os = os;<a name="75" href="#75">75</a> <strong>this</strong>.buffer = buffer;<a name="76" href="#76">76</a> avail = buffer.length;<a name="77" href="#77">77</a> }<a name="78" href="#78">78</a> <a name="79" href="#79">79</a> <em>/**<em>* Creates a new fast buffered output stream by wrapping a given output stream with a given buffer size. </em></em><a name="80" href="#80">80</a> <em> *</em><a name="81" href="#81">81</a> <em> * @param os an output stream to wrap.</em><a name="82" href="#82">82</a> <em> * @param bufSize the size in bytes of the internal buffer.</em><a name="83" href="#83">83</a> <em> */</em><a name="84" href="#84">84</a> <a name="85" href="#85">85</a> <strong>public</strong> <a href="../../../org/archive/io/RecyclingFastBufferedOutputStream.html">RecyclingFastBufferedOutputStream</a>( <strong>final</strong> OutputStream os, <strong>final</strong> <strong>int</strong> bufSize ) {<a name="86" href="#86">86</a> <strong>this</strong>(os, <strong>new</strong> byte [ bufSize]);<a name="87" href="#87">87</a> }<a name="88" href="#88">88</a> <a name="89" href="#89">89</a> <em>/**<em>* Creates a new fast buffered ouptut stream by wrapping a given output stream with a buffer of {@link #DEFAULT_BUFFER_SIZE} bytes. </em></em><a name="90" href="#90">90</a> <em> *</em><a name="91" href="#91">91</a> <em> * @param os an output stream to wrap.</em><a name="92" href="#92">92</a> <em> */</em><a name="93" href="#93">93</a> <strong>public</strong> <a href="../../../org/archive/io/RecyclingFastBufferedOutputStream.html">RecyclingFastBufferedOutputStream</a>( <strong>final</strong> OutputStream os ) {<a name="94" href="#94">94</a> <strong>this</strong>( os, DEFAULT_BUFFER_SIZE );<a name="95" href="#95">95</a> }<a name="96" href="#96">96</a> <a name="97" href="#97">97</a> <strong>private</strong> <strong>void</strong> dumpBufferIfFull() throws IOException {<a name="98" href="#98">98</a> <strong>if</strong> ( avail == 0 ) {<a name="99" href="#99">99</a> os.write( buffer );<a name="100" href="#100">100</a> pos = 0;<a name="101" href="#101">101</a> avail = buffer.length;<a name="102" href="#102">102</a> }<a name="103" href="#103">103</a> }<a name="104" href="#104">104</a> <a name="105" href="#105">105</a> <strong>public</strong> <strong>void</strong> write( <strong>final</strong> <strong>int</strong> b ) throws IOException {<a name="106" href="#106">106</a> avail--;<a name="107" href="#107">107</a> buffer[ pos++ ] = (byte)b;<a name="108" href="#108">108</a> dumpBufferIfFull();<a name="109" href="#109">109</a> }<a name="110" href="#110">110</a> <a name="111" href="#111">111</a> <a name="112" href="#112">112</a> <strong>public</strong> <strong>void</strong> write( <strong>final</strong> byte b[], <strong>int</strong> offset, <strong>int</strong> length ) throws IOException {<a name="113" href="#113">113</a> <strong>if</strong> ( length <= avail ) {<a name="114" href="#114">114</a> System.arraycopy( b, offset, buffer, pos, length );<a name="115" href="#115">115</a> pos += length;<a name="116" href="#116">116</a> avail -= length;<a name="117" href="#117">117</a> dumpBufferIfFull();<a name="118" href="#118">118</a> <strong>return</strong>;<a name="119" href="#119">119</a> }<a name="120" href="#120">120</a> <a name="121" href="#121">121</a> System.arraycopy( b, offset, buffer, pos, avail );<a name="122" href="#122">122</a> os.write( buffer );<a name="123" href="#123">123</a> <a name="124" href="#124">124</a> offset += avail;<a name="125" href="#125">125</a> length -= avail;<a name="126" href="#126">126</a> <a name="127" href="#127">127</a> <strong>final</strong> <strong>int</strong> residual = length % buffer.length;<a name="128" href="#128">128</a> <a name="129" href="#129">129</a> os.write( b, offset, length - residual ); <a name="130" href="#130">130</a> System.arraycopy( b, offset + length - residual, buffer, 0, residual );<a name="131" href="#131">131</a> pos = residual;<a name="132" href="#132">132</a> avail = buffer.length - residual;<a name="133" href="#133">133</a> }<a name="134" href="#134">134</a> <a name="135" href="#135">135</a> <strong>public</strong> <strong>void</strong> close() throws IOException {<a name="136" href="#136">136</a> <strong>if</strong> ( os == <strong>null</strong> ) <strong>return</strong>;<a name="137" href="#137">137</a> <strong>if</strong> ( pos != 0 ) os.write( buffer, 0, pos );<a name="138" href="#138">138</a> <strong>if</strong> ( os != System.out ) os.close();<a name="139" href="#139">139</a> os = <strong>null</strong>;<a name="140" href="#140">140</a> buffer = <strong>null</strong>;<a name="141" href="#141">141</a> }<a name="142" href="#142">142</a> <a name="143" href="#143">143</a> }<a name="144" href="#144">144</a> <a name="145" href="#145">145</a> <a name="146" href="#146">146</a> <em class="comment">// Local Variables:</em><a name="147" href="#147">147</a> <em class="comment">// mode: jde</em><a name="148" href="#148">148</a> <em class="comment">// tab-width: 4</em><a name="149" href="#149">149</a> <em class="comment">// End:</em><a name="150" href="#150">150</a> </pre><hr/><div id="footer">This page was automatically generated by <a href="http://maven.apache.org/">Maven</a></div></body></html>⌨️ 快捷键说明
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