ibessonov commented on code in PR #787: URL: https://github.com/apache/ignite-3/pull/787#discussion_r858560076
########## modules/storage-api/src/main/java/org/apache/ignite/internal/storage/UuidIgniteRowId.java: ########## @@ -0,0 +1,155 @@ +/* + * 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.ignite.internal.storage; + +import java.nio.ByteBuffer; +import java.nio.ByteOrder; +import java.util.UUID; +import org.jetbrains.annotations.NotNull; + +/** + * UUID-based ignite row id implementation. + */ +public final class UuidIgniteRowId implements IgniteRowId { + /* + * The most significant 64 bits. + */ + private final long mostSigBits; + + /* + * The least significant 64 bits. + */ + private final long leastSigBits; + + /** + * Constructor. + * + * @param uuid UUID. + */ + public UuidIgniteRowId(UUID uuid) { + this(uuid.getMostSignificantBits(), uuid.getLeastSignificantBits()); + } + + /** Private constructor. */ + private UuidIgniteRowId(long mostSigBits, long leastSigBits) { + this.mostSigBits = mostSigBits; + this.leastSigBits = leastSigBits; + } + + /** + * Returns {@link UuidIgniteRowId} instance based on {@link UUID#randomUUID()}. Highest two bytes of the most significant bits part will + * encode partition id. + * + * @param partitionId Partition id. + */ + public static IgniteRowId randomRowId(int partitionId) { + UUID randomUuid = UUID.randomUUID(); + + long lsb = randomUuid.getLeastSignificantBits(); + + lsb = (lsb & ~0xFFFFL) | partitionId; + + return new UuidIgniteRowId(randomUuid.getMostSignificantBits(), lsb); + } + + /** {@inheritDoc} */ + @Override + public int partitionId() { + return (int) (leastSigBits & 0xFFFFL); + } + + /** + * Writes row id into a byte buffer. Binary row representation should match natural order defined by {@link #compareTo(Object)} when + * comparing lexicographically. + * + * @param buf Output byte buffer with {@link java.nio.ByteOrder#BIG_ENDIAN} byte order. + * @param signedBytesCompare Defines properties of a target binary comparator. {@code true} if bytes are compared as signed values, + * {@code false} if unsigned. + */ + public void writeTo(ByteBuffer buf, boolean signedBytesCompare) { + assert buf.order() == ByteOrder.BIG_ENDIAN; + + long mask = longBytesSignsMask(signedBytesCompare); + + buf.putLong(mask ^ mostSigBits); + buf.putLong(mask ^ leastSigBits); + } + + /** + * Compares row id with a byte buffer, previously written by a {@link #writeTo(ByteBuffer, boolean)} method. + * + * @param buf Input byte buffer with {@link java.nio.ByteOrder#BIG_ENDIAN} byte order. + * @param signedBytesCompare Defines properties of a binary comparator. {@code true} if bytes are compared as signed values, + * {@code false} if unsigned. + * @return A negative integer, zero, or a positive integer as this row id is less than, equal to, or greater than the specified row id. + */ + public int compareTo(ByteBuffer buf, boolean signedBytesCompare) { Review Comment: If I understand you correctly, we don't. In this specific case, the parameter will be a thread-local direct buffer, that we use to read values from RocksDB without extra allocations. It's not permanently stored anywhere. And you're right, it's kinda a copy of UUID class, just adapted a little bit to our API. -- 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]
