001/*-
002 * #%L
003 * HAPI FHIR - Core Library
004 * %%
005 * Copyright (C) 2014 - 2024 Smile CDR, Inc.
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 *
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package ca.uhn.fhir.util;
021
022import ca.uhn.fhir.i18n.Msg;
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(Msg.code(1807) + "Stream exceeds maximum allowable size: " + myMaxBytes);
056                }
057        }
058
059        /**
060         * Wraps another input stream, counting the number of bytes read.
061         *
062         * @param theWrap the input stream to be wrapped
063         */
064        public CountingAndLimitingInputStream(InputStream theWrap, int theMaxBytes) {
065                myWrap = new CountingInputStream(theWrap);
066                myMaxBytes = theMaxBytes;
067        }
068}