/*
* 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:
*
* 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.
*/
package io.netty.channel;
import io.netty.util.
AbstractReferenceCounted;
import io.netty.util.
IllegalReferenceCountException;
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;
/**
* 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 transfered
* @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) {
if (
file == null) {
throw new
NullPointerException("file");
}
if (
position < 0) {
throw new
IllegalArgumentException("position must be >= 0 but was " +
position);
}
if (
count < 0) {
throw new
IllegalArgumentException("count must be >= 0 but was " +
count);
}
this.
file =
file;
this.
position =
position;
this.
count =
count;
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 transfered
* @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) {
if (
f == null) {
throw new
NullPointerException("f");
}
if (
position < 0) {
throw new
IllegalArgumentException("position must be >= 0 but was " +
position);
}
if (
count < 0) {
throw new
IllegalArgumentException("count must be >= 0 but was " +
count);
}
this.
position =
position;
this.
count =
count;
this.
f =
f;
}
/**
* 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;
}
return
written;
}
@
Override
protected void
deallocate() {
FileChannel file = this.
file;
if (
file == null) {
return;
}
this.
file = null;
try {
file.
close();
} catch (
IOException e) {
if (
logger.
isWarnEnabled()) {
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;
}
}