/*
* @(#)$Id: codetemplate_xbird.xml 943 2006-09-13 07:03:37Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.util.nio;
import java.io.EOFException;
import java.io.IOException;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.WritableByteChannel;
import java.security.AccessController;
import java.security.PrivilegedAction;
import xbird.util.io.IOUtils;
import xbird.util.system.SystemUtils;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public final class NIOUtils {
private NIOUtils() {}
public static void readFully(final ReadableByteChannel channel, final ByteBuffer buf)
throws IOException {
readFully(channel, buf, buf.remaining());
}
public static int readFully(final ReadableByteChannel channel, final ByteBuffer buf, final int length)
throws IOException {
int n, count = 0;
while(-1 != (n = channel.read(buf))) {
count += n;
if(count == length) {
break;
}
}
return count;
}
public static void readFully(final FileChannel channel, final ByteBuffer dst, final long position)
throws IOException {
while(dst.remaining() > 0) {
if(-1 == channel.read(dst, position + dst.position())) {
throw new EOFException();
}
}
}
public static void readFully(final FileChannel channel, final ByteBuffer dst, final long position, final int length)
throws IOException {
int n, count = 0;
while(-1 != (n = channel.read(dst, position))) {
count += n;
if(count == length) {
break;
}
}
}
public static void writeFully(final WritableByteChannel channel, final ByteBuffer buf)
throws IOException {
do {
int written = channel.write(buf);
if(written < 0) {
throw new EOFException();
}
} while(buf.hasRemaining());
}
public static int countingWriteFully(final WritableByteChannel channel, final ByteBuffer buf)
throws IOException {
int written = 0;
do {
final int n = channel.write(buf);
if(n < 0) {
throw new EOFException();
}
written += n;
} while(buf.hasRemaining());
return written;
}
public static void writeFully(final FileChannel channel, final ByteBuffer dst, final long position)
throws IOException {
while(dst.remaining() > 0) {
channel.write(dst, position + dst.position());
}
}
/**
* @link http://weblogs.java.net/blog/jfarcand/archive/2006/07/tricks_and_tips_4.html
*/
public static int readWithTemporarySelector(final SelectableChannel channel, final ByteBuffer byteBuffer, final long readTimeout, final NioSelectorPool selectorPool)
throws IOException {
final int preBufPos = byteBuffer.position();
int byteRead = 0;
Selector readSelector = null;
SelectionKey tmpKey = null;
try {
ReadableByteChannel readableChannel = (ReadableByteChannel) channel;
int count = 1;
while(count > 0) {
count = readableChannel.read(byteBuffer);
if(count > -1) {
byteRead += count;
} else {
byteRead = count;
}
}
if(byteRead == 0 && byteBuffer.position() == preBufPos) {
readSelector = selectorPool.getSelector();
if(readSelector == null) {
return 0;
}
count = 1;
tmpKey = channel.register(readSelector, SelectionKey.OP_READ);
tmpKey.interestOps(tmpKey.interestOps() | SelectionKey.OP_READ);
int code = readSelector.select(readTimeout);
tmpKey.interestOps(tmpKey.interestOps() & (~SelectionKey.OP_READ));
if(code == 0) {
return 0; // Return on the main Selector and try again.
}
while(count > 0) {
count = readableChannel.read(byteBuffer);
if(count > -1) {
byteRead += count;
} else {
byteRead = count;
}
}
} else if(byteRead == 0 && byteBuffer.position() != preBufPos) {
byteRead += (byteBuffer.position() - preBufPos);
}
} finally {
if(tmpKey != null) {
tmpKey.cancel();
}
if(readSelector != null) {
selectorPool.selectNowAndReturnSelector(readSelector);
}
}
return byteRead;
}
public static void close(SelectionKey key) {
IOUtils.closeQuietly(key.channel()); // key is automatically removed with this call.
}
public static void close(Selector selector) {
if(selector != null && selector.isOpen()) {
for(SelectionKey key : selector.keys()) {
close(key);
}
try {
selector.close();
} catch (IOException e) {
;
}
}
}
public static void transferFullyFrom(final ReadableByteChannel src, final long position, final long count, final FileChannel dst)
throws IOException {
long pos = position;
long remaining = count;
while(remaining > 0) {
long wrote = dst.transferFrom(src, pos, remaining);
pos += wrote;
remaining -= wrote;
}
}
/**
* Overlapping mapped files cannot be unmapped on windows.
* The process cannot access the file because another process has locked a portion of the file.
* See Sun bug id #4938372. Fixed in JDK 7.
*
* @link http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038
* @link http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4938372
*/
public static boolean clean(final MappedByteBuffer buffer) {
if(!SystemUtils.isMunmapAvailable()) {
return false;
}
return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
public Boolean run() {
try {
Method getCleanerMethod = buffer.getClass().getMethod("cleaner", new Class[0]);
getCleanerMethod.setAccessible(true);
sun.misc.Cleaner cleaner = (sun.misc.Cleaner) getCleanerMethod.invoke(buffer, new Object[0]);
cleaner.clean();
} catch (Exception e) {
return Boolean.FALSE;
}
return Boolean.TRUE;
}
}).booleanValue();
}
}