2 * Copyright (c) 2021 PANTHEON.tech, s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.controller.cluster.datastore.utils;
10 import static java.util.Objects.requireNonNull;
12 import com.google.common.annotations.Beta;
13 import com.google.common.annotations.VisibleForTesting;
14 import com.google.common.base.MoreObjects;
15 import com.google.common.collect.Collections2;
16 import com.google.common.collect.Range;
17 import com.google.common.collect.RangeSet;
18 import com.google.common.primitives.UnsignedLong;
19 import java.io.DataInput;
20 import java.io.DataOutput;
21 import java.io.IOException;
22 import java.util.Collections;
23 import java.util.NavigableSet;
24 import java.util.TreeSet;
25 import org.eclipse.jdt.annotation.NonNull;
26 import org.opendaylight.yangtools.concepts.Mutable;
27 import org.opendaylight.yangtools.concepts.WritableObjects;
30 * A class holding an equivalent of {@code Set<UnsignedLong>}. It is geared towards efficiently tracking ranges of
31 * objects, similar to what a {@link RangeSet} would do.
34 * Unlike a {@code RangeSet}, though, this class takes advantage of knowing that an unsigned long is a discrete unit
35 * and can be stored in a simple {@code long}.
37 * @author Robert Varga
39 abstract class UnsignedLongSet {
42 public static final class Entry implements Comparable<Entry>, Mutable {
43 // Note: mutable to allow efficient merges.
47 private Entry(final long lowerBits, final long upperBits) {
48 this.lowerBits = lowerBits;
49 this.upperBits = upperBits;
52 static Entry of(final long longBits) {
53 return of(longBits, longBits);
56 static Entry of(final long lowerBits, final long upperBits) {
57 return new Entry(lowerBits, upperBits);
61 public UnsignedLong lower() {
62 return UnsignedLong.fromLongBits(lowerBits);
66 public UnsignedLong upper() {
67 return UnsignedLong.fromLongBits(upperBits);
71 return new Entry(lowerBits, upperBits);
74 // Provides compatibility with RangeSet<UnsignedLong> using [lower, upper + 1)
75 Range<UnsignedLong> toUnsigned() {
76 return Range.closedOpen(UnsignedLong.fromLongBits(lowerBits), UnsignedLong.fromLongBits(upperBits + 1));
79 // These two methods provide the same serialization format as the one we've used to serialize
80 // Range<UnsignedLong>
81 static @NonNull Entry readUnsigned(final DataInput in) throws IOException {
82 final byte hdr = WritableObjects.readLongHeader(in);
83 final long first = WritableObjects.readFirstLong(in, hdr);
84 final long second = WritableObjects.readSecondLong(in, hdr) - 1;
85 if (Long.compareUnsigned(first, second) > 0) {
86 throw new IOException("Lower endpoint " + Long.toUnsignedString(first) + " is greater than upper "
87 + "endpoint " + Long.toUnsignedString(second));
90 return new Entry(first, second);
93 void writeUnsigned(final @NonNull DataOutput out) throws IOException {
94 WritableObjects.writeLongs(out, lowerBits, upperBits + 1);
98 @SuppressWarnings("checkstyle:parameterName")
99 public int compareTo(final Entry o) {
100 return Long.compareUnsigned(lowerBits, o.lowerBits);
104 public int hashCode() {
105 return Long.hashCode(lowerBits) * 31 + Long.hashCode(upperBits);
109 public boolean equals(final Object obj) {
113 if (!(obj instanceof Entry)) {
116 final var other = (Entry) obj;
117 return lowerBits == other.lowerBits && upperBits == other.upperBits;
121 public String toString() {
122 return "[" + Long.toUnsignedString(lowerBits) + ".." + Long.toUnsignedString(upperBits) + "]";
126 // The idea is rather simple, we track a NavigableSet of range entries, ordered by their lower bound. This means
127 // that for a contains() operation we just need the first headSet() entry. For insert operations we just update
128 // either the lower bound or the upper bound of an existing entry. When we do, we also look at prev/next entry and
129 // if they are contiguous with the updated entry, we adjust the entry once more and remove the prev/next entry.
130 private final @NonNull NavigableSet<Entry> ranges;
132 UnsignedLongSet(final NavigableSet<Entry> ranges) {
133 this.ranges = requireNonNull(ranges);
136 public final boolean contains(final long longBits) {
137 final var head = ranges.floor(Entry.of(longBits));
139 && Long.compareUnsigned(head.lowerBits, longBits) <= 0
140 && Long.compareUnsigned(head.upperBits, longBits) >= 0;
143 public final boolean isEmpty() {
144 return ranges.isEmpty();
147 public final int size() {
148 return ranges.size();
151 public abstract @NonNull ImmutableUnsignedLongSet immutableCopy();
153 public final @NonNull MutableUnsignedLongSet mutableCopy() {
154 return new MutableUnsignedLongSet(new TreeSet<>(Collections2.transform(ranges, Entry::copy)));
157 public final @NonNull NavigableSet<Entry> ranges() {
158 return Collections.unmodifiableNavigableSet(ranges);
161 final @NonNull NavigableSet<Entry> trustedRanges() {
166 public final int hashCode() {
167 return ranges.hashCode();
171 public final boolean equals(final Object obj) {
172 return obj == this || obj instanceof UnsignedLongSet && ranges.equals(((UnsignedLongSet) obj).ranges);
176 public final String toString() {
177 final var helper = MoreObjects.toStringHelper(this);
179 final int size = ranges.size();
184 helper.add("span", ranges.first());
187 helper.add("span", Entry.of(ranges.first().lowerBits, ranges.last().upperBits));
190 return helper.add("size", size).toString();