org.xnio.conduits.FixedLengthStreamSinkConduit 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).
/*
* JBoss, Home of Professional Open Source
*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* 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.
*/
package org.xnio.conduits;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import org.xnio.channels.FixedLengthOverflowException;
import org.xnio.channels.FixedLengthUnderflowException;
import org.xnio.channels.StreamSourceChannel;
import static java.lang.Math.min;
import static org.xnio._private.Messages.msg;
/**
* A stream sink conduit with a limited length.
*
* @author David M. Lloyd
*/
public final class FixedLengthStreamSinkConduit extends AbstractStreamSinkConduit implements StreamSinkConduit {
private long remaining;
/**
* Construct a new instance.
*
* @param next the delegate conduit to set
*/
public FixedLengthStreamSinkConduit(final FixedLengthStreamSinkConduit next) {
super(next);
}
public long transferFrom(final FileChannel src, final long position, final long count) throws IOException {
if (count == 0L) return 0L;
final long remaining = this.remaining;
if (remaining == 0L) {
throw msg.fixedOverflow();
}
long res = 0L;
try {
return res = next.transferFrom(src, position, min(count, remaining));
} finally {
this.remaining = remaining - res;
}
}
public long transferFrom(final StreamSourceChannel source, final long count, final ByteBuffer throughBuffer) throws IOException {
if (count == 0L) return 0L;
final long remaining = this.remaining;
if (remaining == 0L) {
throw msg.fixedOverflow();
}
long res = 0L;
try {
return res = next.transferFrom(source, min(count, remaining), throughBuffer);
} finally {
this.remaining = remaining - res;
}
}
@Override
public int writeFinal(ByteBuffer src) throws IOException {
return write(src, true);
}
@Override
public long writeFinal(ByteBuffer[] srcs, int offset, int length) throws IOException {
return write(srcs, offset, length, true);
}
@Override
public int write(final ByteBuffer src) throws IOException {
return write(src, false);
}
@Override
public long write(final ByteBuffer[] srcs, final int offs, final int len) throws IOException {
return write(srcs, offs, len, false);
}
private int write(final ByteBuffer src, final boolean writeFinal) throws IOException {
if (! src.hasRemaining()) {
return 0;
}
int res = 0;
final long remaining = this.remaining;
if (remaining == 0L) {
throw msg.fixedOverflow();
}
try {
final int lim = src.limit();
final int pos = src.position();
if (lim - pos > remaining) {
src.limit((int) (remaining - (long) pos));
try {
return res = doWrite(src, writeFinal);
} finally {
src.limit(lim);
}
} else {
return res = doWrite(src, writeFinal);
}
} finally {
this.remaining = remaining - res;
}
}
private long write(final ByteBuffer[] srcs, final int offs, final int len, boolean writeFinal) throws IOException {
if (len == 0) {
return 0L;
} else if (len == 1) {
return write(srcs[offs], writeFinal);
}
final long remaining = this.remaining;
if (remaining == 0L) {
throw msg.fixedOverflow();
}
long res = 0L;
try {
int lim;
// The total amount of buffer space discovered so far.
long t = 0L;
for (int i = 0; i < len; i ++) {
final ByteBuffer buffer = srcs[i + offs];
// Grow the discovered buffer space by the remaining size of the current buffer.
// We want to capture the limit so we calculate "remaining" ourselves.
t += (lim = buffer.limit()) - buffer.position();
if (t > remaining) {
// only read up to this point, and trim the last buffer by the number of extra bytes
buffer.limit(lim - (int) (t - (remaining)));
try {
return res = doWrite(srcs, offs, i + 1, writeFinal);
} finally {
// restore the original limit
buffer.limit(lim);
}
}
}
if (t == 0L) {
return 0L;
}
// the total buffer space is less than the remaining count.
return res = doWrite(srcs, offs, len, writeFinal);
} finally {
this.remaining = remaining - res;
}
}
private long doWrite(ByteBuffer[] srcs, int offs, int len, boolean writeFinal) throws IOException {
if(writeFinal) {
return next.writeFinal(srcs, offs, len);
} else {
return next.write(srcs, offs, len);
}
}
private int doWrite(ByteBuffer src, boolean writeFinal) throws IOException {
if(writeFinal) {
return next.writeFinal(src);
} else {
return next.write(src);
}
}
public void terminateWrites() throws IOException {
next.terminateWrites();
if (remaining > 0L) {
throw msg.fixedOverflow();
}
}
public void truncateWrites() throws IOException {
next.terminateWrites();
if (remaining > 0L) {
throw msg.fixedOverflow();
}
}
/**
* Get the number of remaining bytes available to read.
*
* @return the number of remaining bytes available to read
*/
public long getRemaining() {
return remaining;
}
}