[HUDI-2443] Hudi KVComparator for all HFile writer usages (#3889)

* [HUDI-2443] Hudi KVComparator for all HFile writer usages

- Hudi relies on custom class shading for Hbase's KeyValue.KVComparator to
  avoid versioning and class loading issues. There are few places which are
  still using the Hbase's comparator class directly and version upgrades
  would make them obsolete. Refactoring the HoodieKVComparator and making
  all HFile writer creation using the same shaded class.

* [HUDI-2443] Hudi KVComparator for all HFile writer usages

- Moving HoodieKVComparator from common.bootstrap.index to common.util

* [HUDI-2443] Hudi KVComparator for all HFile writer usages

- Retaining the old HoodieKVComparatorV2 for boostrap case. Adding the
  new comparator as HoodieKVComparatorV2 to differentiate from the old
  one.

* [HUDI-2443] Hudi KVComparator for all HFile writer usages

 - Renamed HoodieKVComparatorV2 to HoodieMetadataKVComparator and moved it
   under the package org.apache.hudi.metadata.

* Make comparator classname configurable

* Revert new config and address other review comments

Co-authored-by: Sagar Sumit <sagarsumit09@gmail.com>

hudi-common/src/main/java/org/apache/hudi/common/table/log/block/HoodieHFileDataBlock.java

@@ -26,18 +26,16 @@ import org.apache.hudi.common.model.HoodieRecord;
 import org.apache.hudi.common.util.Option;
 import org.apache.hudi.common.util.ValidationUtils;
 import org.apache.hudi.exception.HoodieIOException;
+import org.apache.hudi.io.storage.HoodieHBaseKVComparator;
 import org.apache.hudi.io.storage.HoodieHFileReader;
 
-import org.apache.hadoop.fs.Path;
-import org.apache.log4j.LogManager;
-import org.apache.log4j.Logger;
-
 import org.apache.avro.Schema;
 import org.apache.avro.Schema.Field;
 import org.apache.avro.generic.IndexedRecord;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.io.compress.Compression;
 import org.apache.hadoop.hbase.io.hfile.CacheConfig;
@@ -45,6 +43,10 @@ import org.apache.hadoop.hbase.io.hfile.HFile;
 import org.apache.hadoop.hbase.io.hfile.HFileContext;
 import org.apache.hadoop.hbase.io.hfile.HFileContextBuilder;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+
+import javax.annotation.Nonnull;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -56,8 +58,6 @@ import java.util.Map;
 import java.util.TreeMap;
 import java.util.stream.Collectors;
 
-import javax.annotation.Nonnull;
-
 /**
  * HoodieHFileDataBlock contains a list of records stored inside an HFile format. It is used with the HFile
  * base file format.
@@ -102,7 +102,7 @@ public class HoodieHFileDataBlock extends HoodieDataBlock {
     FSDataOutputStream ostream = new FSDataOutputStream(baos, null);
 
     HFile.Writer writer = HFile.getWriterFactory(conf, cacheConfig)
-        .withOutputStream(ostream).withFileContext(context).create();
+        .withOutputStream(ostream).withFileContext(context).withComparator(new HoodieHBaseKVComparator()).create();
 
     // Serialize records into bytes
     Map<String, byte[]> sortedRecordsMap = new TreeMap<>();

hudi-common/src/main/java/org/apache/hudi/io/storage/HoodieHBaseKVComparator.java

@@ -0,0 +1,29 @@
+/*
+ * 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.hudi.io.storage;
+
+import org.apache.hadoop.hbase.KeyValue;
+
+/**
+ * This class is explicitly used as Key Comparator to work around the hard coded
+ * legacy format class names inside HBase. Otherwise, we will face issues with shading.
+ */
+public class HoodieHBaseKVComparator extends KeyValue.KVComparator {
+}

hudi-common/src/test/java/org/apache/hudi/common/fs/inline/TestInLineFileSystemHFileInLining.java

@@ -19,6 +19,7 @@
 package org.apache.hudi.common.fs.inline;
 
 import org.apache.hudi.common.testutils.FileSystemTestUtils;
+import org.apache.hudi.io.storage.HoodieHBaseKVComparator;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
@@ -92,7 +93,7 @@ public class TestInLineFileSystemHFileInLining {
     HFile.Writer writer = HFile.getWriterFactory(inMemoryConf, cacheConf)
         .withOutputStream(fout)
         .withFileContext(meta)
-        .withComparator(new KeyValue.KVComparator())
+        .withComparator(new HoodieHBaseKVComparator())
         .create();
 
     writeRecords(writer);