nandakumar131 commented on code in PR #3885: URL: https://github.com/apache/ozone/pull/3885#discussion_r1016879347
########## hadoop-hdds/rocksdb-checkpoint-differ/src/main/java/org/apache/ozone/rocksdb/util/ManagedSstFileReader.java: ########## @@ -0,0 +1,126 @@ +/* + * 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 + * <p> + * http://www.apache.org/licenses/LICENSE-2.0 + * <p> + * 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.ozone.rocksdb.util; + +import org.rocksdb.Options; +import org.rocksdb.ReadOptions; +import org.rocksdb.RocksDBException; +import org.rocksdb.SstFileReader; +import org.rocksdb.SstFileReaderIterator; + +import java.io.Closeable; +import java.util.Collection; +import java.util.Iterator; +import java.util.NoSuchElementException; +import java.util.Spliterator; +import java.util.Spliterators; +import java.util.stream.Stream; +import java.util.stream.StreamSupport; + +/** + * ManagedSSTFileReader provides an abstraction layer using which we can + * iterate over multiple underlying SST files transparently. + */ +public class ManagedSstFileReader { + + private final Collection<String> sstFiles; + + public ManagedSstFileReader(final Collection<String> sstFiles) { + this.sstFiles = sstFiles; + } + public Stream<String> getKeyStream() throws RocksDBException { + final OmSstFileIterator iterator = new OmSstFileIterator(sstFiles); + final Spliterator<String> spliterator = Spliterators + .spliteratorUnknownSize(iterator, 0); + return StreamSupport.stream(spliterator, false).onClose(iterator::close); + } + + private static final class OmSstFileIterator implements + Iterator<String>, Closeable { + + private final Iterator<String> fileNameIterator; + private final Options options; + private final ReadOptions readOptions; + private String currentFile; + private SstFileReader currentFileReader; + private SstFileReaderIterator currentFileIterator; + + private OmSstFileIterator(Collection<String> files) + throws RocksDBException { + // TODO: Check if default Options and ReadOptions is enough. + this.options = new Options(); + this.readOptions = new ReadOptions(); Review Comment: Options is to control the behavior of the _database_. ReadOptions is to control the behavior of the _get_ method call. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
