multibytereplaycharsequence.html

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<a name="170" href="#170">170</a> <em>     * the in-memory prefix buffer and the backing file.  Returns a</em>
<a name="171" href="#171">171</a> <em>     * charSequence view onto this new file.</em>
<a name="172" href="#172">172</a> <em>     *</em>
<a name="173" href="#173">173</a> <em>     * @param buffer In-memory buffer of recordings prefix.  We read from</em>
<a name="174" href="#174">174</a> <em>     * here first and will only go to the backing file if &lt;code>size&lt;/code></em>
<a name="175" href="#175">175</a> <em>     * requested is greater than &lt;code>buffer.length&lt;/code>.</em>
<a name="176" href="#176">176</a> <em>     * @param size Total size of stream to replay in bytes.  Used to find</em>
<a name="177" href="#177">177</a> <em>     * EOS. This is total length of content including HTTP headers if</em>
<a name="178" href="#178">178</a> <em>     * present.</em>
<a name="179" href="#179">179</a> <em>     * @param responseBodyStart Where the response body starts in bytes.</em>
<a name="180" href="#180">180</a> <em>     * Used to skip over the HTTP headers if present.</em>
<a name="181" href="#181">181</a> <em>     * @param backingFilename Path to backing file with content in excess of</em>
<a name="182" href="#182">182</a> <em>     * whats in &lt;code>buffer&lt;/code>.</em>
<a name="183" href="#183">183</a> <em>     * @param encoding Encoding to use reading the passed prefix buffer and</em>
<a name="184" href="#184">184</a> <em>     * backing file.  For now, should be java canonical name for the</em>
<a name="185" href="#185">185</a> <em>     * encoding. (If null is passed, we will default to</em>
<a name="186" href="#186">186</a> <em>     * ByteReplayCharSequence).</em>
<a name="187" href="#187">187</a> <em>     *</em>
<a name="188" href="#188">188</a> <em>     * @return A CharBuffer view on decodings of the contents of passed</em>
<a name="189" href="#189">189</a> <em>     * buffer.</em>
<a name="190" href="#190">190</a> <em>     * @throws IOException</em>
<a name="191" href="#191">191</a> <em>     */</em>
<a name="192" href="#192">192</a>     <strong>private</strong> CharBuffer decodeToFile(<a href="../../../org/archive/io/ReplayInputStream.html">ReplayInputStream</a> inStream, 
<a name="193" href="#193">193</a>             String backingFilename, String encoding)
<a name="194" href="#194">194</a>         throws IOException {
<a name="195" href="#195">195</a> 
<a name="196" href="#196">196</a>         CharBuffer charBuffer = <strong>null</strong>;
<a name="197" href="#197">197</a> 
<a name="198" href="#198">198</a>         BufferedReader reader = <strong>new</strong> BufferedReader(
<a name="199" href="#199">199</a>                 <strong>new</strong> InputStreamReader(inStream,encoding));
<a name="200" href="#200">200</a>         
<a name="201" href="#201">201</a>         <strong>this</strong>.decodedFile = <strong>new</strong> File(backingFilename + <span class="string">"."</span> + WRITE_ENCODING);
<a name="202" href="#202">202</a>         BufferedWriter writer = <strong>new</strong> BufferedWriter(
<a name="203" href="#203">203</a>                 <strong>new</strong> OutputStreamWriter(
<a name="204" href="#204">204</a>                         <strong>new</strong> FileOutputStream(<strong>this</strong>.decodedFile), 
<a name="205" href="#205">205</a>                         WRITE_ENCODING)); 
<a name="206" href="#206">206</a> 
<a name="207" href="#207">207</a>         <strong>int</strong> c;
<a name="208" href="#208">208</a>         <strong>while</strong>((c = reader.read())>=0) {
<a name="209" href="#209">209</a>             writer.write(c);
<a name="210" href="#210">210</a>         }
<a name="211" href="#211">211</a>         writer.close();
<a name="212" href="#212">212</a>         
<a name="213" href="#213">213</a>         charBuffer = getReadOnlyMemoryMappedBuffer(<strong>this</strong>.decodedFile).
<a name="214" href="#214">214</a>             asCharBuffer();
<a name="215" href="#215">215</a> 
<a name="216" href="#216">216</a>         <strong>return</strong> charBuffer;
<a name="217" href="#217">217</a>     }
<a name="218" href="#218">218</a> 
<a name="219" href="#219">219</a>     <em>/**<em>*</em></em>
<a name="220" href="#220">220</a> <em>     * Decode passed buffer into a CharBuffer.</em>
<a name="221" href="#221">221</a> <em>     *</em>
<a name="222" href="#222">222</a> <em>     * This method decodes a memory buffer returning a memory buffer.</em>
<a name="223" href="#223">223</a> <em>     *</em>
<a name="224" href="#224">224</a> <em>     * @param buffer In-memory buffer of recordings prefix.  We read from</em>
<a name="225" href="#225">225</a> <em>     * here first and will only go to the backing file if &lt;code>size&lt;/code></em>
<a name="226" href="#226">226</a> <em>     * requested is greater than &lt;code>buffer.length&lt;/code>.</em>
<a name="227" href="#227">227</a> <em>     * @param size Total size of stream to replay in bytes.  Used to find</em>
<a name="228" href="#228">228</a> <em>     * EOS. This is total length of content including HTTP headers if</em>
<a name="229" href="#229">229</a> <em>     * present.</em>
<a name="230" href="#230">230</a> <em>     * @param responseBodyStart Where the response body starts in bytes.</em>
<a name="231" href="#231">231</a> <em>     * Used to skip over the HTTP headers if present.</em>
<a name="232" href="#232">232</a> <em>     * @param encoding Encoding to use reading the passed prefix buffer and</em>
<a name="233" href="#233">233</a> <em>     * backing file.  For now, should be java canonical name for the</em>
<a name="234" href="#234">234</a> <em>     * encoding. (If null is passed, we will default to</em>
<a name="235" href="#235">235</a> <em>     * ByteReplayCharSequence).</em>
<a name="236" href="#236">236</a> <em>     *</em>
<a name="237" href="#237">237</a> <em>     * @return A CharBuffer view on decodings of the contents of passed</em>
<a name="238" href="#238">238</a> <em>     * buffer.</em>
<a name="239" href="#239">239</a> <em>     */</em>
<a name="240" href="#240">240</a>     <strong>private</strong> CharBuffer decodeInMemory(byte[] buffer, <strong>long</strong> size,
<a name="241" href="#241">241</a>             <strong>long</strong> responseBodyStart, String encoding)
<a name="242" href="#242">242</a>     {
<a name="243" href="#243">243</a>         ByteBuffer bb = ByteBuffer.wrap(buffer);
<a name="244" href="#244">244</a>         <em class="comment">// Move past the HTTP header if present.</em>
<a name="245" href="#245">245</a>         bb.position((<strong>int</strong>)responseBodyStart);
<a name="246" href="#246">246</a>         <em class="comment">// Set the end-of-buffer to be end-of-content.</em>
<a name="247" href="#247">247</a>         bb.limit((<strong>int</strong>)size);
<a name="248" href="#248">248</a>         <strong>return</strong> (Charset.forName(encoding)).decode(bb).asReadOnlyBuffer();
<a name="249" href="#249">249</a>     }
<a name="250" href="#250">250</a> 
<a name="251" href="#251">251</a>     <em>/**<em>*</em></em>
<a name="252" href="#252">252</a> <em>     * Create read-only memory-mapped buffer onto passed file.</em>
<a name="253" href="#253">253</a> <em>     *</em>
<a name="254" href="#254">254</a> <em>     * @param file File to get memory-mapped buffer on.</em>
<a name="255" href="#255">255</a> <em>     * @return Read-only memory-mapped ByteBuffer view on to passed file.</em>
<a name="256" href="#256">256</a> <em>     * @throws IOException</em>
<a name="257" href="#257">257</a> <em>     */</em>
<a name="258" href="#258">258</a>     <strong>private</strong> ByteBuffer getReadOnlyMemoryMappedBuffer(File file)
<a name="259" href="#259">259</a>         throws IOException {
<a name="260" href="#260">260</a> 
<a name="261" href="#261">261</a>         ByteBuffer bb = <strong>null</strong>;
<a name="262" href="#262">262</a>         FileInputStream in = <strong>null</strong>;
<a name="263" href="#263">263</a>         FileChannel c = <strong>null</strong>;
<a name="264" href="#264">264</a>         assert file.exists(): <span class="string">"No file "</span> + file.getAbsolutePath();
<a name="265" href="#265">265</a> 
<a name="266" href="#266">266</a>         <strong>try</strong> {
<a name="267" href="#267">267</a>             in = <strong>new</strong> FileInputStream(file);
<a name="268" href="#268">268</a>             c = in.getChannel();
<a name="269" href="#269">269</a>             <em class="comment">// TODO: Confirm the READ_ONLY works.  I recall it not working.</em>
<a name="270" href="#270">270</a>             <em class="comment">// The buffers seem to always say that the buffer is writeable.</em>
<a name="271" href="#271">271</a>             bb = c.map(FileChannel.MapMode.READ_ONLY, 0, c.size()).
<a name="272" href="#272">272</a>                 asReadOnlyBuffer();
<a name="273" href="#273">273</a>         }
<a name="274" href="#274">274</a> 
<a name="275" href="#275">275</a>         <strong>finally</strong> {
<a name="276" href="#276">276</a>             <strong>if</strong> (c != <strong>null</strong> &amp;&amp; c.isOpen()) {
<a name="277" href="#277">277</a>                 c.close();
<a name="278" href="#278">278</a>             }
<a name="279" href="#279">279</a>             <strong>if</strong> (in != <strong>null</strong>) {
<a name="280" href="#280">280</a>                 in.close();
<a name="281" href="#281">281</a>             }
<a name="282" href="#282">282</a>         }
<a name="283" href="#283">283</a> 
<a name="284" href="#284">284</a>         <strong>return</strong> bb;
<a name="285" href="#285">285</a>     }
<a name="286" href="#286">286</a> 
<a name="287" href="#287">287</a>     <strong>private</strong> <strong>void</strong> deleteFile(File fileToDelete) {
<a name="288" href="#288">288</a>         deleteFile(fileToDelete, <strong>null</strong>);        
<a name="289" href="#289">289</a>     }
<a name="290" href="#290">290</a> 
<a name="291" href="#291">291</a>     <strong>private</strong> <strong>void</strong> deleteFile(File fileToDelete, <strong>final</strong> Exception e) {
<a name="292" href="#292">292</a>         <strong>if</strong> (e != <strong>null</strong>) {
<a name="293" href="#293">293</a>             <em class="comment">// Log why the delete to help with debug of java.io.FileNotFoundException:</em>
<a name="294" href="#294">294</a>             <em class="comment">// ....tt53http.ris.UTF-16BE.</em>
<a name="295" href="#295">295</a>             logger.severe(<span class="string">"Deleting "</span> + fileToDelete + <span class="string">" because of "</span>
<a name="296" href="#296">296</a>                 + e.toString());
<a name="297" href="#297">297</a>         }
<a name="298" href="#298">298</a>         <strong>if</strong> (fileToDelete != <strong>null</strong> &amp;&amp; fileToDelete.exists()) {
<a name="299" href="#299">299</a>             fileToDelete.delete();
<a name="300" href="#300">300</a>         }
<a name="301" href="#301">301</a>     }
<a name="302" href="#302">302</a> 
<a name="303" href="#303">303</a>     <strong>public</strong> <strong>void</strong> close()
<a name="304" href="#304">304</a>     {
<a name="305" href="#305">305</a>         <strong>this</strong>.content = <strong>null</strong>;
<a name="306" href="#306">306</a>         deleteFile(<strong>this</strong>.decodedFile);
<a name="307" href="#307">307</a>         <em class="comment">// clear decodedFile -- so that double-close (as in </em>
<a name="308" href="#308">308</a>         <em class="comment">// finalize()) won't delete a later instance with same name</em>
<a name="309" href="#309">309</a>         <em class="comment">// see bug [ 1218961 ] "failed get of replay" in ExtractorHTML... usu: UTF-16BE</em>
<a name="310" href="#310">310</a>         <strong>this</strong>.decodedFile = <strong>null</strong>;
<a name="311" href="#311">311</a>     }
<a name="312" href="#312">312</a> 
<a name="313" href="#313">313</a>     <strong>protected</strong> <strong>void</strong> finalize() throws Throwable
<a name="314" href="#314">314</a>     {
<a name="315" href="#315">315</a>         <strong>super</strong>.finalize();
<a name="316" href="#316">316</a>         <em class="comment">// Maybe TODO: eliminate close here, requiring explicit close instead</em>
<a name="317" href="#317">317</a>         close();
<a name="318" href="#318">318</a>     }
<a name="319" href="#319">319</a> 
<a name="320" href="#320">320</a>     <strong>public</strong> <strong>int</strong> length()
<a name="321" href="#321">321</a>     {
<a name="322" href="#322">322</a>         <strong>return</strong> <strong>this</strong>.content.limit();
<a name="323" href="#323">323</a>     }
<a name="324" href="#324">324</a> 
<a name="325" href="#325">325</a>     <strong>public</strong> <strong>char</strong> <strong>char</strong>At(<strong>int</strong> index)
<a name="326" href="#326">326</a>     {
<a name="327" href="#327">327</a>         <strong>return</strong> <strong>this</strong>.content.get(index);
<a name="328" href="#328">328</a>     }
<a name="329" href="#329">329</a> 
<a name="330" href="#330">330</a>     <strong>public</strong> CharSequence subSequence(<strong>int</strong> start, <strong>int</strong> end) {
<a name="331" href="#331">331</a>         <strong>return</strong> <strong>new</strong> <a href="../../../org/archive/io/CharSubSequence.html">CharSubSequence</a>(<strong>this</strong>, start, end);
<a name="332" href="#332">332</a>     }
<a name="333" href="#333">333</a>     
<a name="334" href="#334">334</a>     <strong>public</strong> String toString() {
<a name="335" href="#335">335</a>         StringBuffer sb = <strong>new</strong> StringBuffer(length());
<a name="336" href="#336">336</a>         <em class="comment">// could use StringBuffer.append(CharSequence) if willing to do 1.5 &amp; up</em>
<a name="337" href="#337">337</a>         <strong>for</strong> (<strong>int</strong> i = 0;i&lt;length();i++) {
<a name="338" href="#338">338</a>             sb.append(charAt(i)); 
<a name="339" href="#339">339</a>         }
<a name="340" href="#340">340</a>         <strong>return</strong> sb.toString();
<a name="341" href="#341">341</a>     }
<a name="342" href="#342">342</a> }
</pre>
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