| 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2015 EfficiOS Inc., Alexandre Montplaisir and others. |
| 3 | * |
| 4 | * All rights reserved. This program and the accompanying materials |
| 5 | * are made available under the terms of the Eclipse Public License v1.0 |
| 6 | * which accompanies this distribution, and is available at |
| 7 | * http://www.eclipse.org/legal/epl-v10.html |
| 8 | * |
| 9 | * Contributors: |
| 10 | * Alexandre Montplaisir - Initial API and implementation |
| 11 | *******************************************************************************/ |
| 12 | |
| 13 | package org.eclipse.tracecompass.segmentstore.core.treemap; |
| 14 | |
| 15 | import static org.eclipse.tracecompass.common.core.NonNullUtils.checkNotNull; |
| 16 | |
| 17 | import java.util.Collection; |
| 18 | import java.util.Iterator; |
| 19 | import java.util.TreeMap; |
| 20 | import java.util.concurrent.locks.ReadWriteLock; |
| 21 | import java.util.concurrent.locks.ReentrantReadWriteLock; |
| 22 | |
| 23 | import org.eclipse.jdt.annotation.Nullable; |
| 24 | import org.eclipse.tracecompass.segmentstore.core.ISegment; |
| 25 | import org.eclipse.tracecompass.segmentstore.core.ISegmentStore; |
| 26 | import org.eclipse.tracecompass.segmentstore.core.SegmentComparators; |
| 27 | |
| 28 | import com.google.common.collect.ImmutableList; |
| 29 | import com.google.common.collect.Iterables; |
| 30 | import com.google.common.collect.Ordering; |
| 31 | import com.google.common.collect.Sets; |
| 32 | import com.google.common.collect.TreeMultimap; |
| 33 | |
| 34 | /** |
| 35 | * Implementation of a {@link ISegmentStore} using in-memory {@link TreeMap}'s. |
| 36 | * This relatively simple implementation holds everything in memory, and as such |
| 37 | * cannot contain too much data. |
| 38 | * |
| 39 | * The TreeMapStore itself is Iterable, and its iteration order will be by |
| 40 | * ascending order of start times. For segments with identical start times, the |
| 41 | * secondary comparator will be the end time. If even those are equal, it will |
| 42 | * defer to the segments' natural ordering ({@link ISegment#compareTo}). |
| 43 | * |
| 44 | * The store's tree maps will not accept duplicate key-value pairs, which means |
| 45 | * that if you want several segments with the same start and end times, make |
| 46 | * sure their compareTo() differentiates them. |
| 47 | * |
| 48 | * Removal operations are not supported. |
| 49 | * |
| 50 | * @param <E> |
| 51 | * The type of segment held in this store |
| 52 | * |
| 53 | * @author Alexandre Montplaisir |
| 54 | */ |
| 55 | public class TreeMapStore<E extends ISegment> implements ISegmentStore<E> { |
| 56 | |
| 57 | private final ReadWriteLock fLock = new ReentrantReadWriteLock(false); |
| 58 | |
| 59 | private final TreeMultimap<Long, E> fStartTimesIndex; |
| 60 | private final TreeMultimap<Long, E> fEndTimesIndex; |
| 61 | |
| 62 | private volatile long fSize; |
| 63 | |
| 64 | private @Nullable transient Iterable<E> fLastSnapshot = null; |
| 65 | |
| 66 | /** |
| 67 | * Constructor |
| 68 | */ |
| 69 | public TreeMapStore() { |
| 70 | /* |
| 71 | * For the start times index, the "key comparator" will compare the |
| 72 | * start times as longs directly. This is the primary comparator for its |
| 73 | * tree map. |
| 74 | * |
| 75 | * The secondary "value" comparator will check the end times first, and |
| 76 | * in the event of a tie, defer to the ISegment's Comparable |
| 77 | * implementation, a.k.a. its natural ordering. |
| 78 | * |
| 79 | * The same is done for the end times index, but swapping the first two |
| 80 | * comparators instead. |
| 81 | */ |
| 82 | fStartTimesIndex = checkNotNull(TreeMultimap.<Long, E> create( |
| 83 | SegmentComparators.LONG_COMPARATOR, |
| 84 | Ordering.from(SegmentComparators.INTERVAL_END_COMPARATOR).compound(Ordering.natural()))); |
| 85 | |
| 86 | fEndTimesIndex = checkNotNull(TreeMultimap.<Long, E> create( |
| 87 | SegmentComparators.LONG_COMPARATOR, |
| 88 | Ordering.from(SegmentComparators.INTERVAL_START_COMPARATOR).compound(Ordering.natural()))); |
| 89 | |
| 90 | fSize = 0; |
| 91 | } |
| 92 | |
| 93 | // ------------------------------------------------------------------------ |
| 94 | // Methods from Collection |
| 95 | // ------------------------------------------------------------------------ |
| 96 | |
| 97 | @Override |
| 98 | public Iterator<E> iterator() { |
| 99 | fLock.readLock().lock(); |
| 100 | try { |
| 101 | Iterable<E> lastSnapshot = fLastSnapshot; |
| 102 | if (lastSnapshot == null) { |
| 103 | lastSnapshot = checkNotNull(ImmutableList.copyOf(fStartTimesIndex.values())); |
| 104 | fLastSnapshot = lastSnapshot; |
| 105 | } |
| 106 | return checkNotNull(lastSnapshot.iterator()); |
| 107 | } finally { |
| 108 | fLock.readLock().unlock(); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | @Override |
| 113 | public boolean add(@Nullable E val) { |
| 114 | if (val == null) { |
| 115 | throw new IllegalArgumentException(); |
| 116 | } |
| 117 | |
| 118 | fLock.writeLock().lock(); |
| 119 | try { |
| 120 | if (fStartTimesIndex.put(Long.valueOf(val.getStart()), val)) { |
| 121 | fEndTimesIndex.put(Long.valueOf(val.getEnd()), val); |
| 122 | fSize++; |
| 123 | fLastSnapshot = null; |
| 124 | return true; |
| 125 | } |
| 126 | return false; |
| 127 | } finally { |
| 128 | fLock.writeLock().unlock(); |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | @Override |
| 133 | public int size() { |
| 134 | return Long.valueOf(fSize).intValue(); |
| 135 | } |
| 136 | |
| 137 | @Override |
| 138 | public boolean isEmpty() { |
| 139 | return (fSize == 0); |
| 140 | } |
| 141 | |
| 142 | @Override |
| 143 | public boolean contains(@Nullable Object o) { |
| 144 | fLock.readLock().lock(); |
| 145 | try { |
| 146 | return fStartTimesIndex.containsValue(o); |
| 147 | } finally { |
| 148 | fLock.readLock().unlock(); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | |
| 153 | @Override |
| 154 | public boolean containsAll(@Nullable Collection<?> c) { |
| 155 | fLock.readLock().lock(); |
| 156 | try { |
| 157 | return fStartTimesIndex.values().containsAll(c); |
| 158 | } finally { |
| 159 | fLock.readLock().unlock(); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | @Override |
| 164 | public Object[] toArray() { |
| 165 | fLock.readLock().lock(); |
| 166 | try { |
| 167 | return checkNotNull(fStartTimesIndex.values().toArray()); |
| 168 | } finally { |
| 169 | fLock.readLock().unlock(); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | @Override |
| 174 | public <T> T[] toArray(T @Nullable[] a) { |
| 175 | fLock.readLock().lock(); |
| 176 | try { |
| 177 | return checkNotNull(fStartTimesIndex.values().toArray(a)); |
| 178 | } finally { |
| 179 | fLock.readLock().unlock(); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | @Override |
| 184 | public boolean remove(@Nullable Object o) { |
| 185 | throw new UnsupportedOperationException(); |
| 186 | } |
| 187 | |
| 188 | @Override |
| 189 | public boolean addAll(@Nullable Collection<? extends E> c) { |
| 190 | if (c == null) { |
| 191 | throw new IllegalArgumentException(); |
| 192 | } |
| 193 | |
| 194 | fLock.writeLock().lock(); |
| 195 | try { |
| 196 | boolean changed = false; |
| 197 | for (E elem : c) { |
| 198 | if (this.add(elem)) { |
| 199 | changed = true; |
| 200 | } |
| 201 | } |
| 202 | return changed; |
| 203 | } finally { |
| 204 | fLock.writeLock().unlock(); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | @Override |
| 209 | public boolean removeAll(@Nullable Collection<?> c) { |
| 210 | throw new UnsupportedOperationException(); |
| 211 | } |
| 212 | |
| 213 | @Override |
| 214 | public boolean retainAll(@Nullable Collection<?> c) { |
| 215 | throw new UnsupportedOperationException(); |
| 216 | } |
| 217 | |
| 218 | @Override |
| 219 | public void clear() { |
| 220 | throw new UnsupportedOperationException(); |
| 221 | } |
| 222 | |
| 223 | // ------------------------------------------------------------------------ |
| 224 | // Methods added by ISegmentStore |
| 225 | // ------------------------------------------------------------------------ |
| 226 | |
| 227 | @Override |
| 228 | public Iterable<E> getIntersectingElements(long position) { |
| 229 | /* |
| 230 | * The intervals intersecting 't' are those whose 1) start time is |
| 231 | * *lower* than 't' AND 2) end time is *higher* than 't'. |
| 232 | */ |
| 233 | fLock.readLock().lock(); |
| 234 | try { |
| 235 | Iterable<E> matchStarts = Iterables.concat(fStartTimesIndex.asMap().headMap(position, true).values()); |
| 236 | Iterable<E> matchEnds = Iterables.concat(fEndTimesIndex.asMap().tailMap(position, true).values()); |
| 237 | return checkNotNull(Sets.intersection(Sets.newHashSet(matchStarts), Sets.newHashSet(matchEnds))); |
| 238 | } finally { |
| 239 | fLock.readLock().unlock(); |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | @Override |
| 244 | public Iterable<E> getIntersectingElements(long start, long end) { |
| 245 | fLock.readLock().lock(); |
| 246 | try { |
| 247 | Iterable<E> matchStarts = Iterables.concat(fStartTimesIndex.asMap().headMap(end, true).values()); |
| 248 | Iterable<E> matchEnds = Iterables.concat(fEndTimesIndex.asMap().tailMap(start, true).values()); |
| 249 | return checkNotNull(Sets.intersection(Sets.newHashSet(matchStarts), Sets.newHashSet(matchEnds))); |
| 250 | } finally { |
| 251 | fLock.readLock().unlock(); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | @Override |
| 256 | public void dispose() { |
| 257 | fLock.writeLock().lock(); |
| 258 | try { |
| 259 | fStartTimesIndex.clear(); |
| 260 | fEndTimesIndex.clear(); |
| 261 | fSize = 0; |
| 262 | } finally { |
| 263 | fLock.writeLock().unlock(); |
| 264 | } |
| 265 | } |
| 266 | } |