rdblue commented on code in PR #5168: URL: https://github.com/apache/iceberg/pull/5168#discussion_r912544384
########## arrow/src/main/java/org/apache/iceberg/arrow/vectorized/parquet/DecimalVectorUtil.java: ########## @@ -0,0 +1,61 @@ +/* + * 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.iceberg.arrow.vectorized.parquet; + +import java.util.Arrays; + +public class DecimalVectorUtil { + + private DecimalVectorUtil() { + } + + /** + * Parquet stores decimal values in big-endian byte order, and Arrow stores them in native byte order. + * When setting the value in Arrow, we call setBigEndian(), and the byte order is reversed if needed. + * Also, the byte array is padded to fill 16 bytes in length by calling Unsafe.setMemory(). The padding + * operation can be slow, so by using this utility method, we can pad before calling setBigEndian() and + * avoid the call to Unsafe.setMemory(). + * + * @param bigEndianBytes The big endian bytes + * @param newLength The length of the byte array to return + * @return The new byte array + */ + public static byte[] padBigEndianBytes(byte[] bigEndianBytes, int newLength) { + if (bigEndianBytes.length == newLength) { + return bigEndianBytes; + } else if (bigEndianBytes.length < newLength) { + byte[] result = new byte[newLength]; + if (bigEndianBytes.length == 0) { + return result; Review Comment: @bryanck, is this hit? It looks like an invalid case because the decimal precision would need to be 0, but we're choosing to return 0 for it. -- 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]
