zlib.html

MINA+API 关于MINA的API

<a name="95" href="#95">95</a>  <em class="jxr_javadoccomment">     * @throws IOException if the decompression of the data failed for some reason.</em>
<a name="96" href="#96">96</a>  <em class="jxr_javadoccomment">     */</em>
<a name="97" href="#97">97</a>      <strong class="jxr_keyword">public</strong> <a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> inflate(<a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> inBuffer) <strong class="jxr_keyword">throws</strong> IOException {
<a name="98" href="#98">98</a>          <strong class="jxr_keyword">if</strong> (mode == MODE_DEFLATER) {
<a name="99" href="#99">99</a>              <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalStateException(<span class="jxr_string">"not initialized as INFLATER"</span>);
<a name="100" href="#100">100</a>         }
<a name="101" href="#101">101</a> 
<a name="102" href="#102">102</a>         byte[] inBytes = <strong class="jxr_keyword">new</strong> byte[inBuffer.limit()];
<a name="103" href="#103">103</a>         inBuffer.get(inBytes).flip();
<a name="104" href="#104">104</a> 
<a name="105" href="#105">105</a>         byte[] outBytes = <strong class="jxr_keyword">new</strong> byte[inBytes.length * 2];
<a name="106" href="#106">106</a>         <a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> outBuffer = IoBuffer.allocate(outBytes.length);
<a name="107" href="#107">107</a>         outBuffer.setAutoExpand(<strong class="jxr_keyword">true</strong>);
<a name="108" href="#108">108</a> 
<a name="109" href="#109">109</a>         zStream.next_in = inBytes;
<a name="110" href="#110">110</a>         zStream.next_in_index = 0;
<a name="111" href="#111">111</a>         zStream.avail_in = inBytes.length;
<a name="112" href="#112">112</a>         zStream.next_out = outBytes;
<a name="113" href="#113">113</a>         zStream.next_out_index = 0;
<a name="114" href="#114">114</a>         zStream.avail_out = outBytes.length;
<a name="115" href="#115">115</a>         <strong class="jxr_keyword">int</strong> retval = 0;
<a name="116" href="#116">116</a> 
<a name="117" href="#117">117</a>         <strong class="jxr_keyword">do</strong> {
<a name="118" href="#118">118</a>             retval = zStream.inflate(JZlib.Z_SYNC_FLUSH);
<a name="119" href="#119">119</a>             <strong class="jxr_keyword">switch</strong> (retval) {
<a name="120" href="#120">120</a>             <strong class="jxr_keyword">case</strong> JZlib.Z_OK:
<a name="121" href="#121">121</a>                 <em class="jxr_comment">// completed decompression, lets copy data and get out</em>
<a name="122" href="#122">122</a>             <strong class="jxr_keyword">case</strong> JZlib.Z_BUF_ERROR:
<a name="123" href="#123">123</a>                 <em class="jxr_comment">// need more space for output. store current output and get more</em>
<a name="124" href="#124">124</a>                 outBuffer.put(outBytes, 0, zStream.next_out_index);
<a name="125" href="#125">125</a>                 zStream.next_out_index = 0;
<a name="126" href="#126">126</a>                 zStream.avail_out = outBytes.length;
<a name="127" href="#127">127</a>                 <strong class="jxr_keyword">break</strong>;
<a name="128" href="#128">128</a>             <strong class="jxr_keyword">default</strong>:
<a name="129" href="#129">129</a>                 <em class="jxr_comment">// unknown error</em>
<a name="130" href="#130">130</a>                 outBuffer = <strong class="jxr_keyword">null</strong>;
<a name="131" href="#131">131</a>                 <strong class="jxr_keyword">if</strong> (zStream.msg == <strong class="jxr_keyword">null</strong>) {
<a name="132" href="#132">132</a>                     <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IOException(<span class="jxr_string">"Unknown error. Error code : "</span>
<a name="133" href="#133">133</a>                             + retval);
<a name="134" href="#134">134</a>                 } <strong class="jxr_keyword">else</strong> {
<a name="135" href="#135">135</a>                     <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IOException(<span class="jxr_string">"Unknown error. Error code : "</span>
<a name="136" href="#136">136</a>                             + retval + <span class="jxr_string">" and message : "</span> + zStream.msg);
<a name="137" href="#137">137</a>                 }
<a name="138" href="#138">138</a>             }
<a name="139" href="#139">139</a>         } <strong class="jxr_keyword">while</strong> (zStream.avail_in &gt; 0);
<a name="140" href="#140">140</a> 
<a name="141" href="#141">141</a>         <strong class="jxr_keyword">return</strong> outBuffer.flip();
<a name="142" href="#142">142</a>     }
<a name="143" href="#143">143</a> 
<a name="144" href="#144">144</a>     <em class="jxr_javadoccomment">/**</em>
<a name="145" href="#145">145</a> <em class="jxr_javadoccomment">     * @param inBuffer the buffer to be compressed. The contents are transferred</em>
<a name="146" href="#146">146</a> <em class="jxr_javadoccomment">     * into a local byte array and the buffer is flipped and returned intact.</em>
<a name="147" href="#147">147</a> <em class="jxr_javadoccomment">     * @return the buffer with the compressed data</em>
<a name="148" href="#148">148</a> <em class="jxr_javadoccomment">     * @throws IOException if the compression of teh buffer failed for some reason</em>
<a name="149" href="#149">149</a> <em class="jxr_javadoccomment">     */</em>
<a name="150" href="#150">150</a>     <strong class="jxr_keyword">public</strong> <a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> deflate(<a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> inBuffer) <strong class="jxr_keyword">throws</strong> IOException {
<a name="151" href="#151">151</a>         <strong class="jxr_keyword">if</strong> (mode == MODE_INFLATER) {
<a name="152" href="#152">152</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalStateException(<span class="jxr_string">"not initialized as DEFLATER"</span>);
<a name="153" href="#153">153</a>         }
<a name="154" href="#154">154</a> 
<a name="155" href="#155">155</a>         byte[] inBytes = <strong class="jxr_keyword">new</strong> byte[inBuffer.limit()];
<a name="156" href="#156">156</a>         inBuffer.get(inBytes).flip();
<a name="157" href="#157">157</a> 
<a name="158" href="#158">158</a>         <em class="jxr_comment">// according to spec, destination buffer should be 0.1% larger</em>
<a name="159" href="#159">159</a>         <em class="jxr_comment">// than source length plus 12 bytes. We add a single byte to safeguard</em>
<a name="160" href="#160">160</a>         <em class="jxr_comment">// against rounds that round down to the smaller value</em>
<a name="161" href="#161">161</a>         <strong class="jxr_keyword">int</strong> outLen = (<strong class="jxr_keyword">int</strong>) Math.round(inBytes.length * 1.001) + 1 + 12;
<a name="162" href="#162">162</a>         byte[] outBytes = <strong class="jxr_keyword">new</strong> byte[outLen];
<a name="163" href="#163">163</a> 
<a name="164" href="#164">164</a>         zStream.next_in = inBytes;
<a name="165" href="#165">165</a>         zStream.next_in_index = 0;
<a name="166" href="#166">166</a>         zStream.avail_in = inBytes.length;
<a name="167" href="#167">167</a>         zStream.next_out = outBytes;
<a name="168" href="#168">168</a>         zStream.next_out_index = 0;
<a name="169" href="#169">169</a>         zStream.avail_out = outBytes.length;
<a name="170" href="#170">170</a> 
<a name="171" href="#171">171</a>         <strong class="jxr_keyword">int</strong> retval = zStream.deflate(JZlib.Z_SYNC_FLUSH);
<a name="172" href="#172">172</a>         <strong class="jxr_keyword">if</strong> (retval != JZlib.Z_OK) {
<a name="173" href="#173">173</a>             outBytes = <strong class="jxr_keyword">null</strong>;
<a name="174" href="#174">174</a>             inBytes = <strong class="jxr_keyword">null</strong>;
<a name="175" href="#175">175</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IOException(<span class="jxr_string">"Compression failed with return value : "</span>
<a name="176" href="#176">176</a>                     + retval);
<a name="177" href="#177">177</a>         }
<a name="178" href="#178">178</a> 
<a name="179" href="#179">179</a>         <a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a> outBuf = <a href="../../../../../org/apache/mina/common/IoBuffer.html">IoBuffer</a>
<a name="180" href="#180">180</a>                 .wrap(outBytes, 0, zStream.next_out_index);
<a name="181" href="#181">181</a> 
<a name="182" href="#182">182</a>         <strong class="jxr_keyword">return</strong> outBuf;
<a name="183" href="#183">183</a>     }
<a name="184" href="#184">184</a> 
<a name="185" href="#185">185</a>     <em class="jxr_javadoccomment">/**</em>
<a name="186" href="#186">186</a> <em class="jxr_javadoccomment">     * Cleans up the resources used by the compression library.</em>
<a name="187" href="#187">187</a> <em class="jxr_javadoccomment">     */</em>
<a name="188" href="#188">188</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> cleanUp() {
<a name="189" href="#189">189</a>         <strong class="jxr_keyword">if</strong> (zStream != <strong class="jxr_keyword">null</strong>) {
<a name="190" href="#190">190</a>             zStream.free();
<a name="191" href="#191">191</a>         }
<a name="192" href="#192">192</a>     }
<a name="193" href="#193">193</a> }
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