6856817: Poor performance of Writer#append with CharBuffer
Summary: Poor performance of Writer#append with CharBuffer
Reviewed-by: rriggs, dfuchs, sherman, shade
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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* 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);
}
}