Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

4926314: Optimize Reader.read(CharBuffer) #1915

Open
wants to merge 15 commits into
base: master
from
@@ -25,6 +25,7 @@

package java.io;

import java.nio.CharBuffer;
import java.util.Objects;

/**
@@ -152,6 +153,23 @@ public int read(char[] cbuf, int off, int len) throws IOException {
}
}

@Override
public int read(CharBuffer target) throws IOException {
synchronized (lock) {
ensureOpen();

if (pos >= count) {
return -1;
}

int avail = count - pos;
int len = Math.min(avail, target.remaining());
target.put(buf, pos, len);
pos += len;
return len;
}
}

/**
* Skips characters. If the stream is already at its end before this method
* is invoked, then no characters are skipped and zero is returned.
@@ -25,6 +25,7 @@

package java.io;

import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import sun.nio.cs.StreamDecoder;
@@ -149,6 +150,10 @@ public String getEncoding() {
return sd.getEncoding();
}

public int read(CharBuffer target) throws IOException {
return sd.read(target);
}

/**
* Reads a single character.
*
@@ -184,12 +184,25 @@ protected Reader(Object lock) {
* @since 1.5
*/
public int read(CharBuffer target) throws IOException {
int len = target.remaining();
char[] cbuf = new char[len];
int n = read(cbuf, 0, len);
if (n > 0)
target.put(cbuf, 0, n);
return n;
int nread;
if (target.hasArray()) {
char[] cbuf = target.array();
int pos = target.position();
int rem = target.limit() - pos;
if (rem <= 0)
return -1;
int off = target.arrayOffset() + pos;
nread = this.read(cbuf, off, rem);
if (nread > 0)
target.position(pos + nread);
} else {
int len = target.remaining();
char[] cbuf = new char[len];
nread = read(cbuf, 0, len);
if (nread > 0)
target.put(cbuf, 0, nread);
}
return nread;

This comment has been minimized.

@AlanBateman

AlanBateman Mar 14, 2021
Contributor

Thanks for bringing this back to just the heap buffer case. This part looks good now.

This comment has been minimized.

@bplb

bplb Mar 19, 2021
Member

Agreed.

}

/**
@@ -206,7 +219,7 @@ public int read(CharBuffer target) throws IOException {
* @throws IOException If an I/O error occurs
*/
public int read() throws IOException {
char cb[] = new char[1];
char[] cb = new char[1];
if (read(cb, 0, 1) == -1)
return -1;
else
@@ -231,7 +244,7 @@ public int read() throws IOException {
*
* @throws IOException If an I/O error occurs
*/
public int read(char cbuf[]) throws IOException {
public int read(char[] cbuf) throws IOException {
return read(cbuf, 0, cbuf.length);
}

@@ -258,13 +271,13 @@ public int read(char cbuf[]) throws IOException {
* or {@code len} is greater than {@code cbuf.length - off}
* @throws IOException If an I/O error occurs
*/
public abstract int read(char cbuf[], int off, int len) throws IOException;
public abstract int read(char[] cbuf, int off, int len) throws IOException;

/** Maximum skip-buffer size */
private static final int maxSkipBufferSize = 8192;

/** Skip buffer, null until allocated */
private char skipBuffer[] = null;
private char[] skipBuffer = null;

/**
* Skips characters. This method will block until some characters are
@@ -0,0 +1,88 @@
/*
* Copyright (c) 2021, 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 4926314
* @summary Test for CharArrayReader#read(CharBuffer).
* @run testng ReadCharBuffer
*/

import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;


import java.io.CharArrayReader;
import java.io.IOException;
import java.io.Reader;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.util.Arrays;

import static org.testng.Assert.assertEquals;

public class ReadCharBuffer {

private static final int BUFFER_SIZE = 7;

@DataProvider(name = "buffers")
public Object[][] createBuffers() {
// test both on-heap and off-heap buffers has they may use different code paths

This comment has been minimized.

@bplb

bplb Apr 16, 2021
Member

"as they may"

return new Object[][]{
new Object[]{CharBuffer.allocate(BUFFER_SIZE)},
new Object[]{ByteBuffer.allocateDirect(BUFFER_SIZE * 2).asCharBuffer()}
};
}

@Test(dataProvider = "buffers")
public void read(CharBuffer buffer) throws IOException {
fillBuffer(buffer);

try (Reader reader = new CharArrayReader("ABCD".toCharArray())) {
buffer.limit(3);
buffer.position(1);
assertEquals(reader.read(buffer), 2);
assertEquals(buffer.position(), 3);
assertEquals(buffer.limit(), 3);

buffer.limit(7);
buffer.position(4);
assertEquals(reader.read(buffer), 2);
assertEquals(buffer.position(), 6);
assertEquals(buffer.limit(), 7);

assertEquals(reader.read(buffer), -1);
}

buffer.clear();
assertEquals(buffer.toString(), "xABxCDx");
}

private void fillBuffer(CharBuffer buffer) {
char[] filler = new char[BUFFER_SIZE];
Arrays.fill(filler, 'x');
buffer.put(filler);
buffer.clear();
}

}
@@ -0,0 +1,88 @@
/*
* Copyright (c) 2021, 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 4926314
* @summary Test for InputStreamReader#read(CharBuffer).
* @run testng ReadCharBuffer
*/

import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;


import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.util.Arrays;

import static java.nio.charset.StandardCharsets.US_ASCII;
import static org.testng.Assert.assertEquals;

public class ReadCharBuffer {

private static final int BUFFER_SIZE = 24;

@DataProvider(name = "buffers")
public Object[][] createBuffers() {
// test both on-heap and off-heap buffers has they make use different code paths

This comment has been minimized.

@bplb

bplb Apr 16, 2021
Member

"as they may"

return new Object[][]{
new Object[]{CharBuffer.allocate(BUFFER_SIZE)},
new Object[]{ByteBuffer.allocateDirect(BUFFER_SIZE * 2).asCharBuffer()}
};
}

@Test(dataProvider = "buffers")
public void read(CharBuffer buffer) throws IOException {
fillBuffer(buffer);

try (Reader reader = new InputStreamReader(new ByteArrayInputStream("ABCDEFGHIJKLMNOPQRTUVWXYZ".getBytes(US_ASCII)), US_ASCII)) {
buffer.limit(7);
buffer.position(1);
assertEquals(reader.read(buffer), 6);
assertEquals(buffer.position(), 7);
assertEquals(buffer.limit(), 7);

buffer.limit(16);
buffer.position(8);
assertEquals(reader.read(buffer), 8);
assertEquals(buffer.position(), 16);
assertEquals(buffer.limit(), 16);
}

buffer.clear();

This comment has been minimized.

@bplb

bplb Feb 16, 2021
Member

I think buffer.rewind() would be more in keeping with the specification verbiage although there will be no practical effect here. Same comment applies below and in the other test ReadCharBuffer.

This comment has been minimized.

@marschall

marschall Mar 13, 2021
Author Contributor

buffer.rewind() would not work in this specific case as it does not reset the limit. I want to assert the entire buffers content to make sure the method didn't accidentally write where it shouldn't have. Therefore limit needs to be set to capacity.

assertEquals(buffer.toString(), "xABCDEFxGHIJKLMNxxxxxxxx");
}

private void fillBuffer(CharBuffer buffer) {
char[] filler = new char[BUFFER_SIZE];
Arrays.fill(filler, 'x');
buffer.put(filler);
buffer.clear();
}

}
ProTip! Use n and p to navigate between commits in a pull request.