/*
* Copyright (C) 2012, 2016 higherfrequencytrading.com
* Copyright (C) 2016 Roman Leventov
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.openhft.chronicle.map;
import com.google.common.collect.ImmutableSet;
import org.jetbrains.annotations.NotNull;
import org.junit.Test;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ThreadLocalRandom;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
public class NestedContextsTest {
@Test
public void nestedContextsTest() throws ExecutionException, InterruptedException {
HashSet<Integer> averageValue = new HashSet<>();
for (int i = 0; i < 5; i++) {
averageValue.add(i);
}
ChronicleMap<Integer, Set<Integer>> graph = ChronicleMap
.of(Integer.class, (Class<Set<Integer>>) (Class) Set.class)
.entries(10)
.averageValue(averageValue)
.actualSegments(2)
.create();
addEdge(graph, 1, 2);
addEdge(graph, 2, 3);
addEdge(graph, 1, 3);
assertEquals(ImmutableSet.of(2, 3), graph.get(1));
assertEquals(ImmutableSet.of(1, 3), graph.get(2));
assertEquals(ImmutableSet.of(1, 2), graph.get(3));
verifyGraphConsistent(graph);
ForkJoinPool pool = new ForkJoinPool(8);
try {
pool.submit(() -> {
ThreadLocalRandom.current().ints().limit(10_000).parallel().forEach(i -> {
int sourceNode = Math.abs(i % 10);
int targetNode;
do {
targetNode = ThreadLocalRandom.current().nextInt(10);
} while (targetNode == sourceNode);
if (i % 2 == 0) {
addEdge(graph, sourceNode, targetNode);
} else {
removeEdge(graph, sourceNode, targetNode);
}
});
}).get();
verifyGraphConsistent(graph);
} finally {
pool.shutdownNow();
}
}
private static void verifyGraphConsistent(ChronicleMap<Integer, Set<Integer>> graph) {
graph.forEach((node, neighbours) ->
neighbours.forEach(neighbour -> assertTrue(graph.get(neighbour).contains(node))));
}
public static boolean addEdge(
ChronicleMap<Integer, Set<Integer>> graph, int source, int target) {
if (source == target)
throw new IllegalArgumentException("loops are forbidden");
ExternalMapQueryContext<Integer, Set<Integer>, ?> sourceC = graph.queryContext(source);
ExternalMapQueryContext<Integer, Set<Integer>, ?> targetC = graph.queryContext(target);
// order for consistent lock acquisition => avoid dead lock
if (sourceC.segmentIndex() <= targetC.segmentIndex()) {
return innerAddEdge(source, sourceC, target, targetC);
} else {
return innerAddEdge(target, targetC, source, sourceC);
}
}
private static boolean innerAddEdge(
int source, ExternalMapQueryContext<Integer, Set<Integer>, ?> sourceContext,
int target, ExternalMapQueryContext<Integer, Set<Integer>, ?> targetContext) {
try (ExternalMapQueryContext<Integer, Set<Integer>, ?> sc = sourceContext) {
try (ExternalMapQueryContext<Integer, Set<Integer>, ?> tc = targetContext) {
sc.updateLock().lock();
tc.updateLock().lock();
MapEntry<Integer, Set<Integer>> sEntry = sc.entry();
if (sEntry != null) {
MapEntry<Integer, Set<Integer>> tEntry = tc.entry();
if (tEntry != null) {
return addEdgeBothPresent(sc, sEntry, source, tc, tEntry, target);
} else {
addEdgePresentAbsent(sc, sEntry, source, tc, target);
return true;
}
} else {
MapEntry<Integer, Set<Integer>> tEntry = tc.entry();
if (tEntry != null) {
addEdgePresentAbsent(tc, tEntry, target, sc, source);
} else {
addEdgeBothAbsent(sc, source, tc, target);
}
return true;
}
}
}
}
private static boolean addEdgeBothPresent(
MapQueryContext<Integer, Set<Integer>, ?> sc,
@NotNull MapEntry<Integer, Set<Integer>> sEntry, int source,
MapQueryContext<Integer, Set<Integer>, ?> tc,
@NotNull MapEntry<Integer, Set<Integer>> tEntry, int target) {
Set<Integer> sNeighbours = sEntry.value().get();
if (sNeighbours.add(target)) {
Set<Integer> tNeighbours = tEntry.value().get();
boolean added = tNeighbours.add(source);
assert added;
sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours));
tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours));
return true;
} else {
return false;
}
}
private static void addEdgePresentAbsent(
MapQueryContext<Integer, Set<Integer>, ?> sc,
@NotNull MapEntry<Integer, Set<Integer>> sEntry, int source,
MapQueryContext<Integer, Set<Integer>, ?> tc, int target) {
Set<Integer> sNeighbours = sEntry.value().get();
boolean added = sNeighbours.add(target);
assert added;
sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours));
addEdgeOneSide(tc, source);
}
private static void addEdgeBothAbsent(MapQueryContext<Integer, Set<Integer>, ?> sc, int source,
MapQueryContext<Integer, Set<Integer>, ?> tc, int target) {
addEdgeOneSide(sc, target);
addEdgeOneSide(tc, source);
}
private static void addEdgeOneSide(MapQueryContext<Integer, Set<Integer>, ?> tc, int source) {
Set<Integer> tNeighbours = new HashSet<>();
tNeighbours.add(source);
MapAbsentEntry<Integer, Set<Integer>> tAbsentEntry = tc.absentEntry();
assert tAbsentEntry != null;
tAbsentEntry.doInsert(tc.wrapValueAsData(tNeighbours));
}
public static boolean removeEdge(
ChronicleMap<Integer, Set<Integer>> graph, int source, int target) {
ExternalMapQueryContext<Integer, Set<Integer>, ?> sourceC = graph.queryContext(source);
ExternalMapQueryContext<Integer, Set<Integer>, ?> targetC = graph.queryContext(target);
// order for consistent lock acquisition => avoid dead lock
if (sourceC.segmentIndex() <= targetC.segmentIndex()) {
return innerRemoveEdge(source, sourceC, target, targetC);
} else {
return innerRemoveEdge(target, targetC, source, sourceC);
}
}
private static boolean innerRemoveEdge(
int source, ExternalMapQueryContext<Integer, Set<Integer>, ?> sourceContext,
int target, ExternalMapQueryContext<Integer, Set<Integer>, ?> targetContext) {
try (ExternalMapQueryContext<Integer, Set<Integer>, ?> sc = sourceContext) {
try (ExternalMapQueryContext<Integer, Set<Integer>, ?> tc = targetContext) {
sc.updateLock().lock();
MapEntry<Integer, Set<Integer>> sEntry = sc.entry();
if (sEntry == null)
return false;
Set<Integer> sNeighbours = sEntry.value().get();
if (!sNeighbours.remove(target))
return false;
tc.updateLock().lock();
MapEntry<Integer, Set<Integer>> tEntry = tc.entry();
if (tEntry == null)
throw new IllegalStateException("target node should be present in the graph");
Set<Integer> tNeighbours = tEntry.value().get();
if (!tNeighbours.remove(source))
throw new IllegalStateException("the target node have an edge to the source");
sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours));
tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours));
return true;
}
}
}
}