| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.cassandra.hints; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.zip.CRC32; |
| |
| import org.apache.cassandra.io.util.ChannelProxy; |
| import org.apache.cassandra.io.util.DataPosition; |
| import org.apache.cassandra.io.util.RandomAccessReader; |
| import org.apache.cassandra.utils.NativeLibrary; |
| |
| /** |
| * A {@link RandomAccessReader} wrapper that calculates the CRC in place. |
| * |
| * Useful for {@link org.apache.cassandra.hints.HintsReader}, for example, where we must verify the CRC, yet don't want |
| * to allocate an extra byte array just that purpose. The CRC can be embedded in the input stream and checked via checkCrc(). |
| * |
| * In addition to calculating the CRC, it allows to enforce a maximum known size. This is needed |
| * so that {@link org.apache.cassandra.db.Mutation.MutationSerializer} doesn't blow up the heap when deserializing a |
| * corrupted sequence by reading a huge corrupted length of bytes via |
| * {@link org.apache.cassandra.utils.ByteBufferUtil#readWithLength(java.io.DataInput)}. |
| */ |
| public class ChecksummedDataInput extends RandomAccessReader.RandomAccessReaderWithOwnChannel |
| { |
| private final CRC32 crc; |
| private int crcPosition; |
| private boolean crcUpdateDisabled; |
| |
| private long limit; |
| private DataPosition limitMark; |
| |
| protected ChecksummedDataInput(Builder builder) |
| { |
| super(builder); |
| |
| crc = new CRC32(); |
| crcPosition = 0; |
| crcUpdateDisabled = false; |
| |
| resetLimit(); |
| } |
| |
| @SuppressWarnings("resource") // channel owned by RandomAccessReaderWithOwnChannel |
| public static ChecksummedDataInput open(File file) |
| { |
| return new Builder(new ChannelProxy(file)).build(); |
| } |
| |
| static class Position implements InputPosition |
| { |
| final long sourcePosition; |
| |
| public Position(long sourcePosition) |
| { |
| super(); |
| this.sourcePosition = sourcePosition; |
| } |
| |
| @Override |
| public long subtract(InputPosition other) |
| { |
| return sourcePosition - ((Position)other).sourcePosition; |
| } |
| } |
| |
| /** |
| * Return a seekable representation of the current position. For compressed files this is chunk position |
| * in file and offset within chunk. |
| */ |
| public InputPosition getSeekPosition() |
| { |
| return new Position(getPosition()); |
| } |
| |
| public void seek(InputPosition pos) |
| { |
| updateCrc(); |
| bufferOffset = ((Position) pos).sourcePosition; |
| buffer.position(0).limit(0); |
| } |
| |
| public void resetCrc() |
| { |
| crc.reset(); |
| crcPosition = buffer.position(); |
| } |
| |
| public void limit(long newLimit) |
| { |
| limit = newLimit; |
| limitMark = mark(); |
| } |
| |
| /** |
| * Returns the position in the source file, which is different for getPosition() for compressed/encrypted files |
| * and may be imprecise. |
| */ |
| protected long getSourcePosition() |
| { |
| return bufferOffset; |
| } |
| |
| public void resetLimit() |
| { |
| limit = Long.MAX_VALUE; |
| limitMark = null; |
| } |
| |
| public void checkLimit(int length) throws IOException |
| { |
| if (limitMark == null) |
| return; |
| |
| if ((bytesPastLimit() + length) > limit) |
| throw new IOException("Digest mismatch exception"); |
| } |
| |
| public long bytesPastLimit() |
| { |
| assert limitMark != null; |
| return bytesPastMark(limitMark); |
| } |
| |
| public boolean checkCrc() throws IOException |
| { |
| try |
| { |
| updateCrc(); |
| |
| // we must disable crc updates in case we rebuffer |
| // when called source.readInt() |
| crcUpdateDisabled = true; |
| return ((int) crc.getValue()) == readInt(); |
| } |
| finally |
| { |
| crcPosition = buffer.position(); |
| crcUpdateDisabled = false; |
| } |
| } |
| |
| @Override |
| public void readFully(byte[] b) throws IOException |
| { |
| checkLimit(b.length); |
| super.readFully(b); |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException |
| { |
| checkLimit(len); |
| return super.read(b, off, len); |
| } |
| |
| @Override |
| public void reBuffer() |
| { |
| updateCrc(); |
| super.reBuffer(); |
| crcPosition = buffer.position(); |
| } |
| |
| public void tryUncacheRead() |
| { |
| NativeLibrary.trySkipCache(getChannel().getFileDescriptor(), 0, getSourcePosition(), getPath()); |
| } |
| |
| private void updateCrc() |
| { |
| if (crcPosition == buffer.position() || crcUpdateDisabled) |
| return; |
| |
| assert crcPosition >= 0 && crcPosition < buffer.position(); |
| |
| ByteBuffer unprocessed = buffer.duplicate(); |
| unprocessed.position(crcPosition) |
| .limit(buffer.position()); |
| |
| crc.update(unprocessed); |
| } |
| |
| public static class Builder extends RandomAccessReader.Builder |
| { |
| public Builder(ChannelProxy channel) |
| { |
| super(channel); |
| } |
| |
| public ChecksummedDataInput build() |
| { |
| return new ChecksummedDataInput(this); |
| } |
| } |
| } |