[GitHub] azagrebin commented on a change in pull request #6501: [FLINK-10041] Extract iterators from RocksDBKeyedStateBackend (inner …

[GitBox <gi...@apache.org>]

azagrebin commented on a change in pull request #6501: [FLINK-10041] Extract iterators from RocksDBKeyedStateBackend (inner …
URL: https://github.com/apache/flink/pull/6501#discussion_r209283561
 
 

 ##########
 File path: flink-state-backends/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/iterator/RocksStateKeysIterator.java
 ##########
 @@ -0,0 +1,137 @@
+/*
+ * 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.flink.contrib.streaming.state.iterator;
+
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.contrib.streaming.state.RocksDBKeySerializationUtils;
+import org.apache.flink.contrib.streaming.state.RocksIteratorWrapper;
+import org.apache.flink.core.memory.ByteArrayInputStreamWithPos;
+import org.apache.flink.core.memory.DataInputViewStreamWrapper;
+import org.apache.flink.util.FlinkRuntimeException;
+
+import javax.annotation.Nonnull;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+
+/**
+ * Adapter class to bridge between {@link RocksIteratorWrapper} and {@link Iterator} to iterate over the keys. This class
+ * is not thread safe.
+ *
+ * @param <K> the type of the iterated objects, which are keys in RocksDB.
+ */
+public class RocksStateKeysIterator<K> implements Iterator<K>, AutoCloseable {
+
+	@Nonnull
+	private final RocksIteratorWrapper iterator;
+
+	@Nonnull
+	private final String state;
+
+	@Nonnull
+	private final TypeSerializer<K> keySerializer;
+
+	@Nonnull
+	private final byte[] namespaceBytes;
+
+	private final boolean ambiguousKeyPossible;
+	private final int keyGroupPrefixBytes;
+	private K nextKey;
+	private K previousKey;
+
+	public RocksStateKeysIterator(
+		@Nonnull RocksIteratorWrapper iterator,
+		@Nonnull String state,
+		@Nonnull TypeSerializer<K> keySerializer,
+		int keyGroupPrefixBytes,
+		boolean ambiguousKeyPossible,
+		@Nonnull byte[] namespaceBytes) {
+		this.iterator = iterator;
+		this.state = state;
+		this.keySerializer = keySerializer;
+		this.keyGroupPrefixBytes = keyGroupPrefixBytes;
+		this.namespaceBytes = namespaceBytes;
+		this.nextKey = null;
+		this.previousKey = null;
+		this.ambiguousKeyPossible = ambiguousKeyPossible;
+	}
+
+	@Override
+	public boolean hasNext() {
+		try {
+			while (nextKey == null && iterator.isValid()) {
+
+				byte[] key = iterator.key();
+
+				ByteArrayInputStreamWithPos inputStream =
 
 Review comment:
   I would suggest to move deserialisation stuff into smaller method, like:
   `Tuple2<K, Integer> deserKeyAndNamespacePos(byte[] keyBytes)`

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services