vamossagar12 commented on a change in pull request #9508: URL: https://github.com/apache/kafka/pull/9508#discussion_r530414938
########## File path: streams/src/main/java/org/apache/kafka/streams/state/internals/RocksDBPrefixIterator.java ########## @@ -0,0 +1,55 @@ +/* + * 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.kafka.streams.state.internals; + +import org.apache.kafka.common.utils.Bytes; +import org.apache.kafka.streams.KeyValue; +import org.apache.kafka.streams.state.KeyValueIterator; +import org.rocksdb.RocksIterator; + +import java.nio.ByteBuffer; +import java.util.Set; + +class RocksDBPrefixIterator extends RocksDbIterator { + private final byte[] rawPrefix; + + RocksDBPrefixIterator(final String name, + final RocksIterator newIterator, + final Set<KeyValueIterator<Bytes, byte[]>> openIterators, + final Bytes prefix) { + super(name, newIterator, openIterators, true); + this.rawPrefix = prefix.get(); + newIterator.seek(rawPrefix); + } + + private boolean prefixEquals(final byte[] prefix1, final byte[] prefix2) { + final int min = Math.min(prefix1.length, prefix2.length); + final ByteBuffer prefix1Slice = ByteBuffer.wrap(prefix1, 0, min); + final ByteBuffer prefix2Slice = ByteBuffer.wrap(prefix2, 0, min); + return prefix1Slice.equals(prefix2Slice); Review comment: Ticket for unit test cases for RocksDBRangeIterator: https://issues.apache.org/jira/browse/KAFKA-10766. Regarding `abcd` being returned as the prefix for `abc`, I added a local test where I added an entry with key `abc` ` entries.add(new KeyValue<>(new Bytes(stringSerializer.serialize(null, "abc")),stringSerializer.serialize(null, "f"))); ` and did a prefixScan for `abcd` ` numberOfKeysReturned = 0; while (keysWithPrefix1.hasNext()) { System.out.println(Arrays.toString(keysWithPrefix1.next().key.get())); numberOfKeysReturned++; } assertThat(numberOfKeysReturned, is(0)); ` That is because the iterator first seeks to the rawPrefix passed (abcd) in this case and then finds keys which match the prefix and are lexicographically more than it. But as you said, going by the method `prefixEquals`, yes there's a possibility there. ---------------------------------------------------------------- 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
