shangxinli commented on code in PR #1000: URL: https://github.com/apache/parquet-mr/pull/1000#discussion_r981648516
########## parquet-hadoop/src/main/java/org/apache/parquet/hadoop/codec/NonBlockedDecompressor.java: ########## @@ -0,0 +1,174 @@ +/* + * 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.parquet.hadoop.codec; + +import org.apache.hadoop.io.compress.Decompressor; +import org.apache.parquet.Preconditions; + +import java.io.IOException; +import java.nio.ByteBuffer; + +abstract public class NonBlockedDecompressor implements Decompressor { + + // Buffer for uncompressed output. This buffer grows as necessary. + private ByteBuffer outputBuffer = ByteBuffer.allocateDirect(0); + + // Buffer for compressed input. This buffer grows as necessary. + private ByteBuffer inputBuffer = ByteBuffer.allocateDirect(0); + + private boolean finished; + + /** + * Fills specified buffer with uncompressed data. Returns actual number + * of bytes of uncompressed data. A return value of 0 indicates that + * {@link #needsInput()} should be called in order to determine if more + * input data is required. + * + * @param buffer Buffer for the compressed data + * @param off Start offset of the data + * @param len Size of the buffer + * @return The actual number of bytes of uncompressed data. + * @throws IOException if reading or decompression fails + */ + @Override + public synchronized int decompress(byte[] buffer, int off, int len) throws IOException { + SnappyUtil.validateBuffer(buffer, off, len); + if (inputBuffer.position() == 0 && !outputBuffer.hasRemaining()) { + return 0; + } + + if (!outputBuffer.hasRemaining()) { + inputBuffer.rewind(); + Preconditions.checkArgument(inputBuffer.position() == 0, "Invalid position of 0."); + Preconditions.checkArgument(outputBuffer.position() == 0, "Invalid position of 0."); + // There is compressed input, decompress it now. + int decompressedSize = uncompressedLength(inputBuffer, len); + if (decompressedSize > outputBuffer.capacity()) { + ByteBuffer oldBuffer = outputBuffer; + outputBuffer = ByteBuffer.allocateDirect(decompressedSize); + CleanUtil.cleanDirectBuffer(oldBuffer); + } + + // Reset the previous outputBuffer (i.e. set position to 0) + outputBuffer.clear(); + int size = uncompress(inputBuffer, outputBuffer); + outputBuffer.limit(size); + // We've decompressed the entire input, reset the input now + inputBuffer.clear(); + inputBuffer.limit(0); + finished = true; + } + + // Return compressed output up to 'len' + int numBytes = Math.min(len, outputBuffer.remaining()); + outputBuffer.get(buffer, off, numBytes); + return numBytes; + } + + /** + * Sets input data for decompression. + * This should be called if and only if {@link #needsInput()} returns + * <code>true</code> indicating that more input data is required. + * (Both native and non-native versions of various Decompressors require + * that the data passed in via <code>b[]</code> remain unmodified until + * the caller is explicitly notified--via {@link #needsInput()}--that the + * buffer may be safely modified. With this requirement, an extra + * buffer-copy can be avoided.) + * + * @param buffer Input data + * @param off Start offset + * @param len Length + */ + @Override + public synchronized void setInput(byte[] buffer, int off, int len) { + SnappyUtil.validateBuffer(buffer, off, len); Review Comment: Should we refactor this SnappyUtil also? -- 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. To unsubscribe, e-mail: dev-unsubscr...@parquet.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
