Myracle commented on code in PR #27483: URL: https://github.com/apache/flink/pull/27483#discussion_r2929811561
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/functions/scalar/InetNtoaFunction.java: ########## @@ -0,0 +1,131 @@ +/* + * 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.table.runtime.functions.scalar; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.data.StringData; +import org.apache.flink.table.functions.BuiltInFunctionDefinitions; +import org.apache.flink.table.functions.SpecializedFunction; + +import javax.annotation.Nullable; + +/** + * Implementation of {@link BuiltInFunctionDefinitions#INET_NTOA}. + * + * <p>This function converts a numeric IPv4 address representation back to its string format. It + * follows the MySQL INET_NTOA function behavior. + * + * <p>The conversion extracts each octet from the numeric value using bit shifting and masking. + * + * <p>Note: This function only supports IPv4 addresses. IPv6 addresses are not supported. + * + * <p><b>Implementation Note:</b> This implementation does not use utility classes such as {@code + * com.google.common.net.InetAddresses} or {@code sun.net.util.IPAddressUtil} because: + * + * <ul> + * <li>The conversion from number to IP string is straightforward and does not benefit from + * external libraries + * <li>Using a custom implementation avoids unnecessary dependencies and object allocations (e.g., + * creating {@code InetAddress} objects) + * <li>{@code sun.net.util.IPAddressUtil} is a JDK internal API requiring {@code --add-exports}, + * which introduces JDK version compatibility issues + * </ul> + * + * <p>Examples: + * + * <ul> + * <li>INET_NTOA(2130706433) returns '127.0.0.1' + * <li>INET_NTOA(167772161) returns '10.0.0.1' + * <li>INET_NTOA(0) returns '0.0.0.0' + * </ul> + */ +@Internal +public class InetNtoaFunction extends BuiltInScalarFunction { + + private static final long MAX_IPV4_VALUE = 0xFFFFFFFFL; + private static final int OCTET_MASK = 0xFF; + private static final int BITS_PER_OCTET = 8; + + public InetNtoaFunction(SpecializedFunction.SpecializedContext context) { + super(BuiltInFunctionDefinitions.INET_NTOA, context); + } + + /** + * Converts a numeric IPv4 address representation (Long) to its string format. + * + * @param ipNumber the numeric representation of the IPv4 address + * @return the IPv4 address string in dotted-decimal notation, or null if input is null or out + * of valid range + */ + public @Nullable StringData eval(@Nullable Long ipNumber) { + if (ipNumber == null) { + return null; + } + return convertToIp(ipNumber); + } + + /** + * Converts a numeric IPv4 address representation (Integer) to its string format. + * + * <p>This overload handles INT type inputs which Flink may pass directly without implicit + * conversion to Long. + * + * @param ipNumber the numeric representation of the IPv4 address + * @return the IPv4 address string in dotted-decimal notation, or null if input is null or out + * of valid range + */ + public @Nullable StringData eval(@Nullable Integer ipNumber) { + if (ipNumber == null) { + return null; + } + // Convert to long, treating negative integers as unsigned + // For example, -1 (0xFFFFFFFF as signed int) should be treated as 4294967295 + return convertToIp(Integer.toUnsignedLong(ipNumber)); + } + + /** + * Internal conversion method. + * + * @param ipNumber the numeric representation + * @return the IPv4 address string, or null if out of valid range + */ + private @Nullable StringData convertToIp(long ipNumber) { + // Check if the number is within valid IPv4 range [0, 4294967295] + if (ipNumber < 0 || ipNumber > MAX_IPV4_VALUE) { + return null; + } + + return StringData.fromString(longToIp(ipNumber)); + } + + /** + * Converts a numeric IPv4 address representation to its string format. + * + * @param ipNumber the numeric representation + * @return the IPv4 address string + */ + private static String longToIp(long ipNumber) { Review Comment: greed on both points. I've simplified the code: Merged convertToIp and longToIp into a single longToIp method that handles both the range validation and the conversion. The intermediate convertToIp method was just a thin wrapper, so merging them removes unnecessary indirection. Inlined the static constants — MAX_IPV4_VALUE (0xFFFFFFFFL), OCTET_MASK (0xFF), and BITS_PER_OCTET (8) are indeed self-explanatory in this context (standard IPv4 bit manipulation), so they don't need named constants. -- 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]
