buchireddy commented on a change in pull request #4321: #4317 Feature/variable length bytes offline dictionary for indexing bytes and string dicts. URL: https://github.com/apache/incubator-pinot/pull/4321#discussion_r300765246
########## File path: pinot-core/src/main/java/org/apache/pinot/core/io/util/VarLengthBytesValueReaderWriter.java ########## @@ -0,0 +1,196 @@ +/** + * 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.pinot.core.io.util; + +import com.google.common.base.Preconditions; +import java.io.Closeable; +import java.io.IOException; +import java.util.Arrays; +import org.apache.pinot.common.utils.StringUtil; +import org.apache.pinot.core.segment.memory.PinotDataBuffer; + +/** + * Implementation of {@link ValueReader} that will allow each value to be of variable + * length and there by avoiding the unnecessary padding. + * + * The layout of the file is as follows: + * <p> Header Section: </p> + * <ul> + * <li> Magic header byte sequence. </li> + * </ul> + * + * <p> Values: </p> + * <ul> + * <li> Integer offsets to start position of byte arrays. </li> + * <li> All byte arrays. </li> + * </ul> + * + * Only sequential writes are supported. + * + * @see FixedByteValueReaderWriter + */ +public class VarLengthBytesValueReaderWriter implements Closeable, ValueReader { + + /** + * Header used to identify the dictionary files written in variable length bytes + * format. Keeping this a mix of alphanumeric with special character to avoid + * collisions with the regular int/string dictionary values written in fixed size + * format. + */ + private static final byte[] MAGIC_HEADER = StringUtil.encodeUtf8("....vl1;"); + private static final int MAGIC_HEADER_LENGTH = MAGIC_HEADER.length; + private static final int INDEX_ARRAY_START_OFFSET = MAGIC_HEADER.length + Integer.BYTES; + + private final PinotDataBuffer _dataBuffer; + private transient int _numElements; + + public VarLengthBytesValueReaderWriter(PinotDataBuffer dataBuffer) { + this._dataBuffer = dataBuffer; + } + + public static long getRequiredSize(byte[][] byteArrays) { Review comment: Filed https://github.com/apache/incubator-pinot/issues/4393 to handle this. ---------------------------------------------------------------- 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 With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
