| /* |
| * 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.net; |
| |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| import java.util.Collection; |
| import java.util.zip.CRC32; |
| |
| import io.netty.channel.ChannelPipeline; |
| import net.jpountz.lz4.LZ4Factory; |
| import net.jpountz.lz4.LZ4SafeDecompressor; |
| |
| import static org.apache.cassandra.net.Crc.*; |
| |
| /** |
| * Framing format that compresses payloads with LZ4, and protects integrity of data in movement with CRCs |
| * (of both header and payload). |
| * |
| * Every on-wire frame contains: |
| * 1. Compressed length (17 bits) |
| * 2. Uncompressed length (17 bits) |
| * 3. {@code isSelfContained} flag (1 bit) |
| * 4. Header padding (5 bits) |
| * 5. CRC24 of Header contents (24 bits) |
| * 6. Compressed Payload (up to 2 ^ 17 - 1 bits) |
| * 7. CRC32 of Compressed Payload (32 bits) |
| * |
| * 0 1 2 3 |
| * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | Compressed Length | Uncompressed Length |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * |C| | CRC24 of Header | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | | |
| * + + |
| * | Compressed Payload | |
| * + + |
| * | | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | CRC32 of Compressed Payload | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| */ |
| final class FrameDecoderLZ4 extends FrameDecoderWith8bHeader |
| { |
| public static FrameDecoderLZ4 fast(BufferPoolAllocator allocator) |
| { |
| return new FrameDecoderLZ4(allocator, LZ4Factory.fastestInstance().safeDecompressor()); |
| } |
| |
| private static final int HEADER_LENGTH = 8; |
| private static final int TRAILER_LENGTH = 4; |
| private static final int HEADER_AND_TRAILER_LENGTH = 12; |
| |
| private static int compressedLength(long header8b) |
| { |
| return ((int) header8b) & 0x1FFFF; |
| } |
| private static int uncompressedLength(long header8b) |
| { |
| return ((int) (header8b >>> 17)) & 0x1FFFF; |
| } |
| private static boolean isSelfContained(long header8b) |
| { |
| return 0 != (header8b & (1L << 34)); |
| } |
| private static int headerCrc(long header8b) |
| { |
| return ((int) (header8b >>> 40)) & 0xFFFFFF; |
| } |
| |
| private final LZ4SafeDecompressor decompressor; |
| |
| private FrameDecoderLZ4(BufferPoolAllocator allocator, LZ4SafeDecompressor decompressor) |
| { |
| super(allocator); |
| this.decompressor = decompressor; |
| } |
| |
| final long readHeader(ByteBuffer frame, int begin) |
| { |
| long header8b = frame.getLong(begin); |
| if (frame.order() == ByteOrder.BIG_ENDIAN) |
| header8b = Long.reverseBytes(header8b); |
| return header8b; |
| } |
| |
| final CorruptFrame verifyHeader(long header8b) |
| { |
| int computeLengthCrc = crc24(header8b, 5); |
| int readLengthCrc = headerCrc(header8b); |
| |
| return readLengthCrc == computeLengthCrc ? null : CorruptFrame.unrecoverable(readLengthCrc, computeLengthCrc); |
| } |
| |
| final int frameLength(long header8b) |
| { |
| return compressedLength(header8b) + HEADER_AND_TRAILER_LENGTH; |
| } |
| |
| final Frame unpackFrame(ShareableBytes bytes, int begin, int end, long header8b) |
| { |
| ByteBuffer input = bytes.get(); |
| |
| boolean isSelfContained = isSelfContained(header8b); |
| int uncompressedLength = uncompressedLength(header8b); |
| |
| CRC32 crc = crc32(); |
| int readFullCrc = input.getInt(end - TRAILER_LENGTH); |
| if (input.order() == ByteOrder.BIG_ENDIAN) |
| readFullCrc = Integer.reverseBytes(readFullCrc); |
| |
| updateCrc32(crc, input, begin + HEADER_LENGTH, end - TRAILER_LENGTH); |
| int computeFullCrc = (int) crc.getValue(); |
| |
| if (readFullCrc != computeFullCrc) |
| return CorruptFrame.recoverable(isSelfContained, uncompressedLength, readFullCrc, computeFullCrc); |
| |
| if (uncompressedLength == 0) |
| { |
| return new IntactFrame(isSelfContained, bytes.slice(begin + HEADER_LENGTH, end - TRAILER_LENGTH)); |
| } |
| else |
| { |
| ByteBuffer out = allocator.get(uncompressedLength); |
| try |
| { |
| int sourceLength = end - (begin + HEADER_LENGTH + TRAILER_LENGTH); |
| decompressor.decompress(input, begin + HEADER_LENGTH, sourceLength, out, 0, uncompressedLength); |
| return new IntactFrame(isSelfContained, ShareableBytes.wrap(out)); |
| } |
| catch (Throwable t) |
| { |
| allocator.put(out); |
| throw t; |
| } |
| } |
| } |
| |
| void decode(Collection<Frame> into, ShareableBytes bytes) |
| { |
| // TODO: confirm in assembly output that we inline the relevant nested method calls |
| decode(into, bytes, HEADER_LENGTH); |
| } |
| |
| void addLastTo(ChannelPipeline pipeline) |
| { |
| pipeline.addLast("frameDecoderLZ4", this); |
| } |
| } |