001package ca.uhn.fhir.util;
002
003/*-
004 * #%L
005 * HAPI FHIR - Core Library
006 * %%
007 * Copyright (C) 2014 - 2022 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 ca.uhn.fhir.i18n.Msg;
024import com.google.common.io.CountingInputStream;
025
026import java.io.IOException;
027import java.io.InputStream;
028
029public class CountingAndLimitingInputStream extends InputStream {
030        private final int myMaxBytes;
031        private final CountingInputStream myWrap;
032
033        @Override
034        public int read() throws IOException {
035                int retVal = myWrap.read();
036                validateCount();
037                return retVal;
038        }
039
040        @Override
041        public int read(byte[] b, int off, int len) throws IOException {
042                int retVal = myWrap.read(b, off, len);
043                validateCount();
044                return retVal;
045        }
046
047        @Override
048        public int read(byte[] theRead) throws IOException {
049                int retVal = myWrap.read(theRead);
050                validateCount();
051                return retVal;
052        }
053
054        private void validateCount() throws IOException {
055                if (myWrap.getCount() > myMaxBytes) {
056                        throw new IOException(Msg.code(1807) + "Stream exceeds maximum allowable size: " + myMaxBytes);
057                }
058        }
059
060
061        /**
062         * Wraps another input stream, counting the number of bytes read.
063         *
064         * @param theWrap the input stream to be wrapped
065         */
066        public CountingAndLimitingInputStream(InputStream theWrap, int theMaxBytes) {
067                myWrap = new CountingInputStream(theWrap);
068                myMaxBytes = theMaxBytes;
069        }
070}