io.netty.channel.DefaultFileRegion Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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:
*
* https://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.
*/
package io.netty.channel;
import io.netty.util.AbstractReferenceCounted;
import io.netty.util.IllegalReferenceCountException;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
/**
* Default {@link FileRegion} implementation which transfer data from a {@link FileChannel} or {@link File}.
*
* Be aware that the {@link FileChannel} will be automatically closed once {@link #refCnt()} returns
* {@code 0}.
*/
public class DefaultFileRegion extends AbstractReferenceCounted implements FileRegion {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(DefaultFileRegion.class);
private final File f;
private final long position;
private final long count;
private long transferred;
private FileChannel file;
/**
* Create a new instance
*
* @param file the {@link FileChannel} which should be transferred
* @param position the position from which the transfer should start
* @param count the number of bytes to transfer
*/
public DefaultFileRegion(FileChannel file, long position, long count) {
this.file = ObjectUtil.checkNotNull(file, "file");
this.position = checkPositiveOrZero(position, "position");
this.count = checkPositiveOrZero(count, "count");
this.f = null;
}
/**
* Create a new instance using the given {@link File}. The {@link File} will be opened lazily or
* explicitly via {@link #open()}.
*
* @param f the {@link File} which should be transferred
* @param position the position from which the transfer should start
* @param count the number of bytes to transfer
*/
public DefaultFileRegion(File f, long position, long count) {
this.f = ObjectUtil.checkNotNull(f, "f");
this.position = checkPositiveOrZero(position, "position");
this.count = checkPositiveOrZero(count, "count");
}
/**
* Returns {@code true} if the {@link FileRegion} has a open file-descriptor
*/
public boolean isOpen() {
return file != null;
}
/**
* Explicitly open the underlying file-descriptor if not done yet.
*/
public void open() throws IOException {
if (!isOpen() && refCnt() > 0) {
// Only open if this DefaultFileRegion was not released yet.
file = new RandomAccessFile(f, "r").getChannel();
}
}
@Override
public long position() {
return position;
}
@Override
public long count() {
return count;
}
@Deprecated
@Override
public long transfered() {
return transferred;
}
@Override
public long transferred() {
return transferred;
}
@Override
public long transferTo(WritableByteChannel target, long position) throws IOException {
long count = this.count - position;
if (count < 0 || position < 0) {
throw new IllegalArgumentException(
"position out of range: " + position +
" (expected: 0 - " + (this.count - 1) + ')');
}
if (count == 0) {
return 0L;
}
if (refCnt() == 0) {
throw new IllegalReferenceCountException(0);
}
// Call open to make sure fc is initialized. This is a no-oop if we called it before.
open();
long written = file.transferTo(this.position + position, count, target);
if (written > 0) {
transferred += written;
} else if (written == 0) {
// If the amount of written data is 0 we need to check if the requested count is bigger then the
// actual file itself as it may have been truncated on disk.
//
// See https://github.com/netty/netty/issues/8868
validate(this, position);
}
return written;
}
@Override
protected void deallocate() {
FileChannel file = this.file;
if (file == null) {
return;
}
this.file = null;
try {
file.close();
} catch (IOException e) {
logger.warn("Failed to close a file.", e);
}
}
@Override
public FileRegion retain() {
super.retain();
return this;
}
@Override
public FileRegion retain(int increment) {
super.retain(increment);
return this;
}
@Override
public FileRegion touch() {
return this;
}
@Override
public FileRegion touch(Object hint) {
return this;
}
static void validate(DefaultFileRegion region, long position) throws IOException {
// If the amount of written data is 0 we need to check if the requested count is bigger then the
// actual file itself as it may have been truncated on disk.
//
// See https://github.com/netty/netty/issues/8868
long size = region.file.size();
long count = region.count - position;
if (region.position + count + position > size) {
throw new IOException("Underlying file size " + size + " smaller then requested count " + region.count);
}
}
}