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6856817: Poor performance of Writer#append with CharBuffer

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Poor performance of Writer#append with CharBuffer

Reviewed-by: rriggs, dfuchs, sherman, shade
This commit is contained in:
Vyom Tewari 2015-12-02 21:32:40 +01:00
parent af7402f069
commit dc93a924ee
3 changed files with 198 additions and 1 deletions
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23
jdk/src/java.base/share/classes/java/io/OutputStreamWriter.java
View File

@ -25,6 +25,7 @@
package java.io;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import sun.nio.cs.StreamEncoder;
@ -220,6 +221,28 @@ public class OutputStreamWriter extends Writer {
se.write(str, off, len);
}
@Override
public Writer append(CharSequence csq, int start, int end) throws IOException {
if (csq == null) {
write("null".subSequence(start, end).toString());
return this;
} else {
return append(csq.subSequence(start, end));
}
}
@Override
public Writer append(CharSequence csq) throws IOException {
if (csq == null) {
se.write("null");
} else if (csq instanceof CharBuffer) {
se.write((CharBuffer) csq);
} else {
se.write(csq.toString());
}
return this;
}
/**
* Flushes the stream.
*

20
jdk/src/java.base/share/classes/sun/nio/cs/StreamEncoder.java
View File

@ -135,6 +135,18 @@ public class StreamEncoder extends Writer
write(cbuf, 0, len);
}
public void write(CharBuffer cb) throws IOException {
int position = cb.position();
try {
synchronized (lock) {
ensureOpen();
implWrite(cb);
}
} finally {
cb.position(position);
}
}
public void flush() throws IOException {
synchronized (lock) {
ensureOpen();
@ -266,9 +278,15 @@ public class StreamEncoder extends Writer
throws IOException
{
CharBuffer cb = CharBuffer.wrap(cbuf, off, len);
implWrite(cb);
}
if (haveLeftoverChar)
void implWrite(CharBuffer cb)
throws IOException
{
if (haveLeftoverChar) {
flushLeftoverChar(cb, false);
}
while (cb.hasRemaining()) {
CoderResult cr = encoder.encode(cb, bb, false);

156
jdk/test/java/io/Writer/Bug6856817.java Normal file
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@ -0,0 +1,156 @@
/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 6856817
* @summary optimize the Writer.append(CharSequence) method
*/
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
/**
*
* @author vyom.tewari@oacle.com
*/
public class Bug6856817 {
private static final String str = "This is just a test string that i am using it to test the CharBuffer.append(CharSequence csq) for little bit performance improvement.";
private static final int BUF_SIZE = 1024;
/**
*
* @param args
*/
public static void main(String args[]) {
CharBuffer charBuffer = CharBuffer.allocate(BUF_SIZE);
File file = new File("temp.txt");
file.deleteOnExit();
charBuffer.put(str);
charBuffer.flip();
checkFileContent(charBuffer, file, str);
charBuffer.position(10);
checkFileContent(charBuffer, file, str.substring(10));
charBuffer.position(charBuffer.limit());
checkFileContent(charBuffer, file, str.substring(charBuffer.limit()));
char arr[] = new char[BUF_SIZE];
charBuffer = CharBuffer.wrap(arr);
charBuffer.put(str);
charBuffer.flip();
checkFileContent(charBuffer, file, str);
charBuffer.position(10);
checkFileContent(charBuffer, file, str.substring(10));
charBuffer.position(charBuffer.limit());
checkFileContent(charBuffer, file, str.substring(charBuffer.limit()));
char secArr[] = new char[BUF_SIZE];
charBuffer = CharBuffer.wrap(secArr);
charBuffer.put(str);
charBuffer.position(5);
charBuffer.limit(str.length() - 7);
charBuffer = charBuffer.slice();
checkFileContent(charBuffer, file, str.substring(5, (str.length() - 7)));
charBuffer.position(10);
checkFileContent(charBuffer, file, str.substring(15, (str.length() - 7)));
charBuffer.position(charBuffer.limit());
checkFileContent(charBuffer, file, str.substring(charBuffer.limit()));
charBuffer = ByteBuffer.allocate(BUF_SIZE).asCharBuffer();
charBuffer.put(str);
charBuffer.flip();
checkFileContent(charBuffer, file, str);
charBuffer.position(10);
checkFileContent(charBuffer, file, str.substring(10));
charBuffer.position(charBuffer.limit());
checkFileContent(charBuffer, file, str.substring(charBuffer.limit()));
charBuffer = ByteBuffer.allocateDirect(1024).asCharBuffer();
charBuffer.put(str);
charBuffer.flip();
checkFileContent(charBuffer, file, str);
charBuffer.position(10);
checkFileContent(charBuffer, file, str.substring(10));
charBuffer.position(charBuffer.limit());
checkFileContent(charBuffer, file, str.substring(charBuffer.limit()));
}
private static void checkFileContent(CharBuffer charBuffer, File file, String expectedValue) {
OutputStreamWriter writer = null;
FileReader reader = null;
int position, limit;
position = charBuffer.position();
limit = charBuffer.limit();
try {
OutputStream outputStream = new FileOutputStream(file);
writer = new OutputStreamWriter(outputStream);
writer.append(charBuffer);
writer.close();
if (!isEqual(position, charBuffer.position())) {
System.out.println(": failed");
throw new RuntimeException("buffer position before write: " + position + " and position after write: " + charBuffer.position());
}
if (!isEqual(limit, charBuffer.limit())) {
System.out.println(": failed");
throw new RuntimeException("buffer limit before write: " + limit + " and limit after write: " + charBuffer.limit());
}
reader = new FileReader(file);
char arr[] = new char[BUF_SIZE];
int byteRead = reader.read(arr);
if (byteRead != -1) {
String stringRead = new String(arr, 0, byteRead);
if (expectedValue.equals(stringRead)) {
System.out.println(": passed");
} else {
System.out.println(": failed");
throw new RuntimeException("expected :" + expectedValue + " and got:" + stringRead);
}
}
} catch (IOException ex) {
ex.printStackTrace();
throw new RuntimeException(ex);
} finally {
try {
if (writer != null) {
writer.close();
}
if (reader != null) {
reader.close();
}
} catch (IOException ex) {
throw new RuntimeException(ex);
}
}
}
private static boolean isEqual(final int first, final int second) {
return (first == second);
}
}