001package ca.uhn.fhir.util;
002
003/*-
004 * #%L
005 * HAPI FHIR - Core Library
006 * %%
007 * Copyright (C) 2014 - 2021 Smile CDR, Inc.
008 * %%
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *      http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 * #L%
021 */
022
023import com.google.common.io.CountingInputStream;
024
025import java.io.IOException;
026import java.io.InputStream;
027
028public class CountingAndLimitingInputStream extends InputStream {
029        private final int myMaxBytes;
030        private final CountingInputStream myWrap;
031
032        @Override
033        public int read() throws IOException {
034                int retVal = myWrap.read();
035                validateCount();
036                return retVal;
037        }
038
039        @Override
040        public int read(byte[] b, int off, int len) throws IOException {
041                int retVal = myWrap.read(b, off, len);
042                validateCount();
043                return retVal;
044        }
045
046        @Override
047        public int read(byte[] theRead) throws IOException {
048                int retVal = myWrap.read(theRead);
049                validateCount();
050                return retVal;
051        }
052
053        private void validateCount() throws IOException {
054                if (myWrap.getCount() > myMaxBytes) {
055                        throw new IOException("Stream exceeds maximum allowable size: " + myMaxBytes);
056                }
057        }
058
059
060        /**
061         * Wraps another input stream, counting the number of bytes read.
062         *
063         * @param theWrap the input stream to be wrapped
064         */
065        public CountingAndLimitingInputStream(InputStream theWrap, int theMaxBytes) {
066                myWrap = new CountingInputStream(theWrap);
067                myMaxBytes = theMaxBytes;
068        }
069}