com.google.common.graph.AbstractDirectedNetworkConnections Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright (C) 2016 The Guava Authors
*
* Licensed 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 com.google.common.graph;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.graph.Graphs.checkNonNegative;
import static com.google.common.graph.Graphs.checkPositive;
import static java.util.Objects.requireNonNull;
import com.google.common.collect.Iterables;
import com.google.common.collect.Iterators;
import com.google.common.collect.Sets;
import com.google.common.collect.UnmodifiableIterator;
import com.google.common.math.IntMath;
import java.util.AbstractSet;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import javax.annotation.CheckForNull;
/**
* A base implementation of {@link NetworkConnections} for directed networks.
*
* @author James Sexton
* @param Node parameter type
* @param Edge parameter type
*/
@ElementTypesAreNonnullByDefault
abstract class AbstractDirectedNetworkConnections implements NetworkConnections {
/** Keys are edges incoming to the origin node, values are the source node. */
final Map inEdgeMap;
/** Keys are edges outgoing from the origin node, values are the target node. */
final Map outEdgeMap;
private int selfLoopCount;
AbstractDirectedNetworkConnections(Map inEdgeMap, Map outEdgeMap, int selfLoopCount) {
this.inEdgeMap = checkNotNull(inEdgeMap);
this.outEdgeMap = checkNotNull(outEdgeMap);
this.selfLoopCount = checkNonNegative(selfLoopCount);
checkState(selfLoopCount <= inEdgeMap.size() && selfLoopCount <= outEdgeMap.size());
}
@Override
public Set adjacentNodes() {
return Sets.union(predecessors(), successors());
}
@Override
public Set incidentEdges() {
return new AbstractSet() {
@Override
public UnmodifiableIterator iterator() {
Iterable incidentEdges =
(selfLoopCount == 0)
? Iterables.concat(inEdgeMap.keySet(), outEdgeMap.keySet())
: Sets.union(inEdgeMap.keySet(), outEdgeMap.keySet());
return Iterators.unmodifiableIterator(incidentEdges.iterator());
}
@Override
public int size() {
return IntMath.saturatedAdd(inEdgeMap.size(), outEdgeMap.size() - selfLoopCount);
}
@Override
public boolean contains(@CheckForNull Object obj) {
return inEdgeMap.containsKey(obj) || outEdgeMap.containsKey(obj);
}
};
}
@Override
public Set inEdges() {
return Collections.unmodifiableSet(inEdgeMap.keySet());
}
@Override
public Set outEdges() {
return Collections.unmodifiableSet(outEdgeMap.keySet());
}
@Override
public N adjacentNode(E edge) {
// Since the reference node is defined to be 'source' for directed graphs,
// we can assume this edge lives in the set of outgoing edges.
// (We're relying on callers to call this method only with an edge that's in the graph.)
return requireNonNull(outEdgeMap.get(edge));
}
@Override
public N removeInEdge(E edge, boolean isSelfLoop) {
if (isSelfLoop) {
checkNonNegative(--selfLoopCount);
}
N previousNode = inEdgeMap.remove(edge);
// We're relying on callers to call this method only with an edge that's in the graph.
return requireNonNull(previousNode);
}
@Override
public N removeOutEdge(E edge) {
N previousNode = outEdgeMap.remove(edge);
// We're relying on callers to call this method only with an edge that's in the graph.
return requireNonNull(previousNode);
}
@Override
public void addInEdge(E edge, N node, boolean isSelfLoop) {
checkNotNull(edge);
checkNotNull(node);
if (isSelfLoop) {
checkPositive(++selfLoopCount);
}
N previousNode = inEdgeMap.put(edge, node);
checkState(previousNode == null);
}
@Override
public void addOutEdge(E edge, N node) {
checkNotNull(edge);
checkNotNull(node);
N previousNode = outEdgeMap.put(edge, node);
checkState(previousNode == null);
}
}