liyafan82 commented on a change in pull request #8949: URL: https://github.com/apache/arrow/pull/8949#discussion_r585195604
########## File path: java/compression/src/main/java/org/apache/arrow/compression/Lz4CompressionCodec.java ########## @@ -0,0 +1,159 @@ +/* + * 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.arrow.compression; + +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; + +import org.apache.arrow.flatbuf.CompressionType; +import org.apache.arrow.memory.ArrowBuf; +import org.apache.arrow.memory.BufferAllocator; +import org.apache.arrow.memory.util.MemoryUtil; +import org.apache.arrow.util.Preconditions; +import org.apache.arrow.vector.compression.CompressionCodec; +import org.apache.arrow.vector.compression.CompressionUtil; +import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorInputStream; +import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorOutputStream; +import org.apache.commons.compress.utils.IOUtils; + +import io.netty.util.internal.PlatformDependent; + +/** + * Compression codec for the LZ4 algorithm. + */ +public class Lz4CompressionCodec implements CompressionCodec { + + @Override + public ArrowBuf compress(BufferAllocator allocator, ArrowBuf uncompressedBuffer) { + Preconditions.checkArgument(uncompressedBuffer.writerIndex() <= Integer.MAX_VALUE, + "The uncompressed buffer size exceeds the integer limit"); + + if (uncompressedBuffer.writerIndex() == 0L) { + // shortcut for empty buffer + ArrowBuf compressedBuffer = allocator.buffer(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH); + compressedBuffer.setLong(0, 0); + compressedBuffer.writerIndex(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH); + uncompressedBuffer.close(); + return compressedBuffer; + } + + try { + ArrowBuf compressedBuffer = doCompress(allocator, uncompressedBuffer); + long compressedLength = compressedBuffer.writerIndex() - CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH; + if (compressedLength > uncompressedBuffer.writerIndex()) { + // compressed buffer is larger, send the raw buffer + compressedBuffer.close(); + compressedBuffer = CompressionUtil.compressRawBuffer(allocator, uncompressedBuffer); + } + + uncompressedBuffer.close(); + return compressedBuffer; + } catch (IOException e) { + throw new RuntimeException(e); + } + } + + private ArrowBuf doCompress(BufferAllocator allocator, ArrowBuf uncompressedBuffer) throws IOException { + byte[] inBytes = new byte[(int) uncompressedBuffer.writerIndex()]; + PlatformDependent.copyMemory(uncompressedBuffer.memoryAddress(), inBytes, 0, uncompressedBuffer.writerIndex()); + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + try (InputStream in = new ByteArrayInputStream(inBytes); + OutputStream out = new FramedLZ4CompressorOutputStream(baos)) { + IOUtils.copy(in, out); + } + + byte[] outBytes = baos.toByteArray(); + + ArrowBuf compressedBuffer = allocator.buffer(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + outBytes.length); + + long uncompressedLength = uncompressedBuffer.writerIndex(); + if (!MemoryUtil.LITTLE_ENDIAN) { + uncompressedLength = Long.reverseBytes(uncompressedLength); + } + // first 8 bytes reserved for uncompressed length, to be consistent with the + // C++ implementation. + compressedBuffer.setLong(0, uncompressedLength); + + PlatformDependent.copyMemory( + outBytes, 0, compressedBuffer.memoryAddress() + CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH, outBytes.length); + compressedBuffer.writerIndex(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + outBytes.length); + return compressedBuffer; + } + + @Override + public ArrowBuf decompress(BufferAllocator allocator, ArrowBuf compressedBuffer) { + Preconditions.checkArgument(compressedBuffer.writerIndex() <= Integer.MAX_VALUE, + "The compressed buffer size exceeds the integer limit"); + + Preconditions.checkArgument(compressedBuffer.writerIndex() >= CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH, + "Not enough data to decompress."); + + long decompressedLength = compressedBuffer.getLong(0); + if (!MemoryUtil.LITTLE_ENDIAN) { + decompressedLength = Long.reverseBytes(decompressedLength); + } + + if (decompressedLength == 0L) { + // shortcut for empty buffer + compressedBuffer.close(); + return allocator.getEmpty(); + } + + if (decompressedLength == CompressionUtil.NO_COMPRESSION_LENGTH) { + // no compression + return CompressionUtil.decompressRawBuffer(compressedBuffer); + } + + try { + ArrowBuf decompressedBuffer = doDecompress(allocator, compressedBuffer); + compressedBuffer.close(); Review comment: This is a known issue. We will fix it ASAP. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
