[
https://issues.apache.org/jira/browse/PARQUET-2196?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17622577#comment-17622577
]
ASF GitHub Bot commented on PARQUET-2196:
-----------------------------------------
wgtmac commented on code in PR #1000:
URL: https://github.com/apache/parquet-mr/pull/1000#discussion_r1002407221
##########
parquet-hadoop/src/main/java/org/apache/parquet/hadoop/codec/Lz4RawCodec.java:
##########
@@ -0,0 +1,112 @@
+/*
+ * 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.conf.Configurable;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.io.compress.CompressionCodec;
+import org.apache.hadoop.io.compress.CompressionInputStream;
+import org.apache.hadoop.io.compress.CompressionOutputStream;
+import org.apache.hadoop.io.compress.Compressor;
+import org.apache.hadoop.io.compress.Decompressor;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Lz4 raw compression codec for Parquet. This codec type has been introduced
+ * into the parquet format since version 2.9.0. It differs from the Lz4Codec
+ * shipped with Apache Hadoop by removing the light frame header which includes
+ * 4 byte for uncompressed length and 4 byte for compressed length. In the
+ * Apache Arrow implementation, these two Lz4 codecs are recognized as LZ4_RAW
+ * and LZ4_HADOOP to minimize the confusion at its best. Please check the link
+ * below for reference.
+ * https://github.com/apache/parquet-format/blob/master/Compression.md
+ */
+public class Lz4RawCodec implements Configurable, CompressionCodec {
+
+ private Configuration conf;
+
+ // Hadoop config for how big to make intermediate buffers.
+ public static final String BUFFER_SIZE_CONFIG = "io.file.buffer.size";
+
+ private static final int DEFAULT_BUFFER_SIZE_CONFIG = 4 * 1024;
Review Comment:
In order to keep the same behavior with the snappy codec, I think it is
better to keep the same default value.
##########
parquet-hadoop/src/main/java/org/apache/parquet/hadoop/codec/NonBlockedCompressor.java:
##########
@@ -0,0 +1,186 @@
+/*
+ * 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.conf.Configuration;
+import org.apache.hadoop.io.compress.Compressor;
+import org.apache.parquet.Preconditions;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * This class is a wrapper around the underlying compressor. It always consumes
+ * the entire input in setInput and compresses it as one compressed block.
+ */
+abstract public class NonBlockedCompressor implements Compressor {
+
+ // Buffer for compressed output. This buffer grows as necessary.
+ private ByteBuffer outputBuffer = ByteBuffer.allocateDirect(0);
+
+ // Buffer for uncompressed input. This buffer grows as necessary.
+ private ByteBuffer inputBuffer = ByteBuffer.allocateDirect(0);
+
+ private long bytesRead = 0L;
+ private long bytesWritten = 0L;
+ private boolean finishCalled = false;
+
+ /**
+ * Fills specified buffer with compressed data. Returns actual number
+ * of bytes of compressed data. A return value of 0 indicates that
+ * 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 compressed data.
+ */
+ @Override
+ public synchronized int compress(byte[] buffer, int off, int len) throws
IOException {
+ SnappyUtil.validateBuffer(buffer, off, len);
Review Comment:
I've added a comment for explanation.
> Support LZ4_RAW codec
> ---------------------
>
> Key: PARQUET-2196
> URL: https://issues.apache.org/jira/browse/PARQUET-2196
> Project: Parquet
> Issue Type: Improvement
> Components: parquet-mr
> Reporter: Gang Wu
> Priority: Major
>
> There is a long history about the LZ4 interoperability of parquet files
> between parquet-mr and parquet-cpp (which is now in the Apache Arrow).
> Attached links are the evidence. In short, a new LZ4_RAW codec type has been
> introduced since parquet format v2.9.0. However, only parquet-cpp supports
> LZ4_RAW. The parquet-mr library still uses the old Hadoop-provided LZ4 codec
> and cannot read parquet files with LZ4_RAW.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
