writerpoolmember.html

用JAVA编写的,在做实验的时候留下来的,本来想删的,但是传上来,大家分享吧

<a name="326" href="#326">326</a>                 (3 + OCCUPIED_SUFFIX.length()));
<a name="327" href="#327">327</a>         } <strong>else</strong> {
<a name="328" href="#328">328</a>             <strong>return</strong> name;
<a name="329" href="#329">329</a>         }
<a name="330" href="#330">330</a>     }
<a name="331" href="#331">331</a> 
<a name="332" href="#332">332</a> 	<em>/**<em>*</em></em>
<a name="333" href="#333">333</a> <em>	 * Get this file.</em>
<a name="334" href="#334">334</a> <em>	 *</em>
<a name="335" href="#335">335</a> <em>	 * Used by junit test to test for creation and when {@link WriterPool} wants</em>
<a name="336" href="#336">336</a> <em>     * to invalidate a file.</em>
<a name="337" href="#337">337</a> <em>	 *</em>
<a name="338" href="#338">338</a> <em>	 * @return The current file.</em>
<a name="339" href="#339">339</a> <em>	 */</em>
<a name="340" href="#340">340</a>     <strong>public</strong> File getFile() {
<a name="341" href="#341">341</a>         <strong>return</strong> <strong>this</strong>.f;
<a name="342" href="#342">342</a>     }
<a name="343" href="#343">343</a> 
<a name="344" href="#344">344</a>     <em>/**<em>*</em></em>
<a name="345" href="#345">345</a> <em>     * Post write tasks.</em>
<a name="346" href="#346">346</a> <em>     * </em>
<a name="347" href="#347">347</a> <em>     * Has side effects.  Will open new file if we're at the upperbound.</em>
<a name="348" href="#348">348</a> <em>     * If we're writing compressed files, it will wrap output stream with a</em>
<a name="349" href="#349">349</a> <em>     * GZIP writer with side effect that GZIP header is written out on the</em>
<a name="350" href="#350">350</a> <em>     * stream.</em>
<a name="351" href="#351">351</a> <em>     *</em>
<a name="352" href="#352">352</a> <em>     * @exception IOException</em>
<a name="353" href="#353">353</a> <em>     */</em>
<a name="354" href="#354">354</a>     <strong>protected</strong> <strong>void</strong> preWriteRecordTasks()
<a name="355" href="#355">355</a>     throws IOException {
<a name="356" href="#356">356</a>         checkSize();
<a name="357" href="#357">357</a>         <strong>if</strong> (<strong>this</strong>.compressed) {
<a name="358" href="#358">358</a>             <em class="comment">// Wrap stream in GZIP Writer.</em>
<a name="359" href="#359">359</a>             <em class="comment">// The below construction immediately writes the GZIP 'default'</em>
<a name="360" href="#360">360</a>             <em class="comment">// header out on the underlying stream.</em>
<a name="361" href="#361">361</a>             <strong>this</strong>.out = <strong>new</strong> CompressedStream(<strong>this</strong>.out);
<a name="362" href="#362">362</a>         }
<a name="363" href="#363">363</a>     }
<a name="364" href="#364">364</a> 
<a name="365" href="#365">365</a>     <em>/**<em>*</em></em>
<a name="366" href="#366">366</a> <em>     * Post file write tasks.</em>
<a name="367" href="#367">367</a> <em>     * If compressed, finishes up compression and flushes stream so any</em>
<a name="368" href="#368">368</a> <em>     * subsequent checks get good reading.</em>
<a name="369" href="#369">369</a> <em>     *</em>
<a name="370" href="#370">370</a> <em>     * @exception IOException</em>
<a name="371" href="#371">371</a> <em>     */</em>
<a name="372" href="#372">372</a>     <strong>protected</strong> <strong>void</strong> postWriteRecordTasks()
<a name="373" href="#373">373</a>     throws IOException {
<a name="374" href="#374">374</a>         <strong>if</strong> (<strong>this</strong>.compressed) {
<a name="375" href="#375">375</a>             CompressedStream o = (CompressedStream)<strong>this</strong>.out;
<a name="376" href="#376">376</a>             o.finish();
<a name="377" href="#377">377</a>             o.flush();
<a name="378" href="#378">378</a>             <strong>this</strong>.out = o.getWrappedStream();
<a name="379" href="#379">379</a>         }
<a name="380" href="#380">380</a>     }
<a name="381" href="#381">381</a>     
<a name="382" href="#382">382</a> 	<em>/**<em>*</em></em>
<a name="383" href="#383">383</a> <em>     * Postion in current physical file.</em>
<a name="384" href="#384">384</a> <em>     * Used making accounting of bytes written.</em>
<a name="385" href="#385">385</a> <em>	 * @return Position in underlying file.  Call before or after writing</em>
<a name="386" href="#386">386</a> <em>     * records *only* to be safe.</em>
<a name="387" href="#387">387</a> <em>	 * @throws IOException</em>
<a name="388" href="#388">388</a> <em>	 */</em>
<a name="389" href="#389">389</a>     <strong>public</strong> <strong>long</strong> getPosition() throws IOException {
<a name="390" href="#390">390</a>         <strong>long</strong> position = 0;
<a name="391" href="#391">391</a>         <strong>if</strong> (<strong>this</strong>.out != <strong>null</strong>) {
<a name="392" href="#392">392</a>             <strong>this</strong>.out.flush();
<a name="393" href="#393">393</a>         }
<a name="394" href="#394">394</a>         <strong>if</strong> (<strong>this</strong>.fos != <strong>null</strong>) {
<a name="395" href="#395">395</a>             <em class="comment">// Call flush on underlying file though probably not needed assuming</em>
<a name="396" href="#396">396</a>             <em class="comment">// above this.out.flush called through to this.fos.</em>
<a name="397" href="#397">397</a>             <strong>this</strong>.fos.flush();
<a name="398" href="#398">398</a>             position = <strong>this</strong>.fos.getChannel().position();
<a name="399" href="#399">399</a>         }
<a name="400" href="#400">400</a>         <strong>return</strong> position;
<a name="401" href="#401">401</a>     }
<a name="402" href="#402">402</a> 
<a name="403" href="#403">403</a>     <strong>public</strong> <strong>boolean</strong> isCompressed() {
<a name="404" href="#404">404</a>         <strong>return</strong> compressed;
<a name="405" href="#405">405</a>     }
<a name="406" href="#406">406</a>     
<a name="407" href="#407">407</a>     <strong>protected</strong> <strong>void</strong> write(<strong>final</strong> byte [] b) throws IOException {
<a name="408" href="#408">408</a>     	<strong>this</strong>.out.write(b);
<a name="409" href="#409">409</a>     }
<a name="410" href="#410">410</a>     
<a name="411" href="#411">411</a> 	<strong>protected</strong> <strong>void</strong> flush() throws IOException {
<a name="412" href="#412">412</a> 		<strong>this</strong>.out.flush();
<a name="413" href="#413">413</a> 	}
<a name="414" href="#414">414</a> 
<a name="415" href="#415">415</a> 	<strong>protected</strong> <strong>void</strong> write(byte[] b, <strong>int</strong> off, <strong>int</strong> len) throws IOException {
<a name="416" href="#416">416</a> 		<strong>this</strong>.out.write(b, off, len);
<a name="417" href="#417">417</a> 	}
<a name="418" href="#418">418</a> 
<a name="419" href="#419">419</a> 	<strong>protected</strong> <strong>void</strong> write(<strong>int</strong> b) throws IOException {
<a name="420" href="#420">420</a> 		<strong>this</strong>.out.write(b);
<a name="421" href="#421">421</a> 	}
<a name="422" href="#422">422</a> 	
<a name="423" href="#423">423</a> 	<strong>protected</strong> <strong>void</strong> readFullyFrom(<strong>final</strong> InputStream is, <strong>final</strong> <strong>long</strong> recordLength,
<a name="424" href="#424">424</a> 			<strong>final</strong> byte [] b)
<a name="425" href="#425">425</a> 	throws IOException {
<a name="426" href="#426">426</a>         <strong>int</strong> read = b.length;
<a name="427" href="#427">427</a>         <strong>int</strong> total = 0;
<a name="428" href="#428">428</a>         <strong>while</strong>((read = is.read(b)) != -1 &amp;&amp; total &lt; recordLength) {
<a name="429" href="#429">429</a>         	total += read;
<a name="430" href="#430">430</a>             write(b, 0, read);
<a name="431" href="#431">431</a>         }
<a name="432" href="#432">432</a>         <strong>if</strong> (total != recordLength) {
<a name="433" href="#433">433</a>         	<strong>throw</strong> <strong>new</strong> IOException(<span class="string">"Read "</span> + total + <span class="string">" but expected "</span> +
<a name="434" href="#434">434</a>         	    recordLength);
<a name="435" href="#435">435</a>         }
<a name="436" href="#436">436</a> 	}
<a name="437" href="#437">437</a> 	
<a name="438" href="#438">438</a>     <strong>public</strong> <strong>void</strong> close() throws IOException {
<a name="439" href="#439">439</a>         <strong>if</strong> (<strong>this</strong>.out == <strong>null</strong>) {
<a name="440" href="#440">440</a>             <strong>return</strong>;
<a name="441" href="#441">441</a>         }
<a name="442" href="#442">442</a>         <strong>this</strong>.out.close();
<a name="443" href="#443">443</a>         <strong>this</strong>.out = <strong>null</strong>;
<a name="444" href="#444">444</a>         <strong>this</strong>.fos = <strong>null</strong>;
<a name="445" href="#445">445</a>         <strong>if</strong> (<strong>this</strong>.f != <strong>null</strong> &amp;&amp; <strong>this</strong>.f.exists()) {
<a name="446" href="#446">446</a>             String path = <strong>this</strong>.f.getAbsolutePath();
<a name="447" href="#447">447</a>             <strong>if</strong> (path.endsWith(OCCUPIED_SUFFIX)) {
<a name="448" href="#448">448</a>                 File f = <strong>new</strong> File(path.substring(0,
<a name="449" href="#449">449</a>                         path.length() - OCCUPIED_SUFFIX.length()));
<a name="450" href="#450">450</a>                 <strong>if</strong> (!<strong>this</strong>.f.renameTo(f)) {
<a name="451" href="#451">451</a>                     logger.warning(<span class="string">"Failed rename of "</span> + path);
<a name="452" href="#452">452</a>                 }
<a name="453" href="#453">453</a>                 <strong>this</strong>.f = f;
<a name="454" href="#454">454</a>             }
<a name="455" href="#455">455</a>             
<a name="456" href="#456">456</a>             logger.info(<span class="string">"Closed "</span> + <strong>this</strong>.f.getAbsolutePath() +
<a name="457" href="#457">457</a>                     <span class="string">", size "</span> + <strong>this</strong>.f.length());
<a name="458" href="#458">458</a>         }
<a name="459" href="#459">459</a>     }
<a name="460" href="#460">460</a>     
<a name="461" href="#461">461</a>     <strong>protected</strong> OutputStream getOutputStream() {
<a name="462" href="#462">462</a>     	<strong>return</strong> <strong>this</strong>.out;
<a name="463" href="#463">463</a>     }
<a name="464" href="#464">464</a>     
<a name="465" href="#465">465</a> 	<strong>protected</strong> String getCreateTimestamp() {
<a name="466" href="#466">466</a> 		<strong>return</strong> createTimestamp;
<a name="467" href="#467">467</a> 	}
<a name="468" href="#468">468</a>     
<a name="469" href="#469">469</a>     
<a name="470" href="#470">470</a>     <em>/**<em>*</em></em>
<a name="471" href="#471">471</a> <em>     * An override so we get access to underlying output stream.</em>
<a name="472" href="#472">472</a> <em>     * @author stack</em>
<a name="473" href="#473">473</a> <em>     */</em>
<a name="474" href="#474">474</a>     <strong>private</strong> <strong>class</strong> CompressedStream <strong>extends</strong> GZIPOutputStream {
<a name="475" href="#475">475</a>         <strong>public</strong> CompressedStream(OutputStream out)
<a name="476" href="#476">476</a>         throws IOException {
<a name="477" href="#477">477</a>             <strong>super</strong>(out);
<a name="478" href="#478">478</a>         }
<a name="479" href="#479">479</a>         
<a name="480" href="#480">480</a>         <em>/**<em>*</em></em>
<a name="481" href="#481">481</a> <em>         * @return Reference to stream being compressed.</em>
<a name="482" href="#482">482</a> <em>         */</em>
<a name="483" href="#483">483</a>         OutputStream getWrappedStream() {
<a name="484" href="#484">484</a>             <strong>return</strong> <strong>this</strong>.out;
<a name="485" href="#485">485</a>         }
<a name="486" href="#486">486</a>     }
<a name="487" href="#487">487</a> }
</pre>
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