org.xnio.streams.LimitedInputStream 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 2010 Red Hat, Inc. and/or its affiliates, and individual
* contributors as indicated by the @author tags.
*
* 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.streams;
import static org.xnio._private.Messages.msg;
import java.io.IOException;
import java.io.InputStream;
/**
* An input stream which truncates the underlying stream to the given length.
*
* @author David M. Lloyd
*/
public final class LimitedInputStream extends InputStream {
private final InputStream delegate;
private long remaining;
private long mark = -1L;
/**
* Construct a new instance.
*
* @param delegate the delegate stream
* @param size the maximum size to pass
*/
public LimitedInputStream(final InputStream delegate, final long size) {
this.delegate = delegate;
remaining = size;
}
/** {@inheritDoc} */
public int read() throws IOException {
final long remaining = this.remaining;
if (remaining > 0) {
final int b = delegate.read();
if (b >= 0) this.remaining = remaining - 1;
return b;
} else {
return -1;
}
}
/** {@inheritDoc} */
public int read(final byte[] b, final int off, final int len) throws IOException {
final long remaining = this.remaining;
if (remaining == 0L) {
return -1;
}
final int cnt = delegate.read(b, off, (int) Math.min((long)len, remaining));
if (cnt == -1) {
return -1;
}
this.remaining = remaining - cnt;
return cnt;
}
/** {@inheritDoc} */
public long skip(final long n) throws IOException {
final long remaining = this.remaining;
if (remaining == 0L || n <= 0L) {
return 0L;
}
final long cnt = delegate.skip(Math.min(n, remaining));
if (cnt > 0L) {
this.remaining = remaining - cnt;
}
return cnt;
}
/** {@inheritDoc} */
public int available() throws IOException {
return Math.min(delegate.available(), (int) Math.min((long)Integer.MAX_VALUE, remaining));
}
/** {@inheritDoc} */
public void close() throws IOException {
remaining = 0;
delegate.close();
}
/** {@inheritDoc} */
public void mark(final int limit) {
if (markSupported()) {
delegate.mark(limit);
mark = remaining;
}
}
/** {@inheritDoc} */
public void reset() throws IOException {
final long mark = this.mark;
if (mark == -1L) {
throw msg.markNotSet();
}
delegate.reset();
remaining = mark;
}
/** {@inheritDoc} */
public boolean markSupported() {
return delegate.markSupported();
}
}