org.jboss.marshalling.LimitedByteInput Maven / Gradle / Ivy
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* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., 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.jboss.marshalling;
import java.io.IOException;
/**
* A limited byte input stream. Throws an exception if too many bytes are read.
*/
public class LimitedByteInput extends ByteInputStream {
private final long limit;
private long count;
/**
* Create a new instance.
*
* @param byteInput the byte input to read from
* @param limit the maximum number of bytes to read
*/
public LimitedByteInput(final ByteInput byteInput, final long limit) {
super(byteInput);
this.limit = limit;
}
/** {@inheritDoc} */
public int read() throws IOException {
final long count = this.count;
if (count < limit) try {
return super.read();
} finally {
this.count = count + 1;
}
throw new IOException("Limit exceeded");
}
/** {@inheritDoc} */
public int read(final byte[] b, final int off, final int len) throws IOException {
final long count = this.count;
final long limit = this.limit;
final int ret;
if (count >= limit) {
throw new IOException("Limit exceeded");
} else if (count + len >= limit) {
int rem = (int) (limit - count);
ret = super.read(b, off, rem);
} else {
ret = super.read(b, off, len);
}
this.count = count + (long) ret;
return ret;
}
/** {@inheritDoc} */
public long skip(final long n) throws IOException {
final long count = this.count;
final long limit = this.limit;
final long ret;
if (count >= limit) {
throw new IOException("Limit exceeded");
} else if (count + n >= limit) {
int rem = (int) (limit - count);
ret = super.skip(rem);
} else {
ret = super.skip(n);
}
this.count = count + ret;
return ret;
}
}