com.facebook.presto.jdbc.internal.guava.graph.ConfigurableMutableNetwork Maven / Gradle / Ivy
/*
* 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.facebook.presto.jdbc.internal.guava.graph;
import static com.facebook.presto.jdbc.internal.guava.base.Preconditions.checkArgument;
import static com.facebook.presto.jdbc.internal.guava.base.Preconditions.checkNotNull;
import static com.facebook.presto.jdbc.internal.guava.base.Preconditions.checkState;
import static com.facebook.presto.jdbc.internal.guava.graph.GraphConstants.PARALLEL_EDGES_NOT_ALLOWED;
import static com.facebook.presto.jdbc.internal.guava.graph.GraphConstants.REUSING_EDGE;
import static com.facebook.presto.jdbc.internal.guava.graph.GraphConstants.SELF_LOOPS_NOT_ALLOWED;
import com.facebook.presto.jdbc.internal.guava.collect.ImmutableList;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
/**
* Configurable implementation of {@link MutableNetwork} that supports both directed and undirected
* graphs. Instances of this class should be constructed with {@link NetworkBuilder}.
*
* Time complexities for mutation methods are all O(1) except for {@code removeNode(N node)},
* which is in O(d_node) where d_node is the degree of {@code node}.
*
* @author James Sexton
* @author Joshua O'Madadhain
* @author Omar Darwish
* @param Node parameter type
* @param Edge parameter type
*/
final class ConfigurableMutableNetwork extends ConfigurableNetwork
implements MutableNetwork {
/** Constructs a mutable graph with the properties specified in {@code builder}. */
ConfigurableMutableNetwork(NetworkBuilder super N, ? super E> builder) {
super(builder);
}
@Override
@CanIgnoreReturnValue
public boolean addNode(N node) {
checkNotNull(node, "node");
if (containsNode(node)) {
return false;
}
addNodeInternal(node);
return true;
}
/**
* Adds {@code node} to the graph and returns the associated {@link NetworkConnections}.
*
* @throws IllegalStateException if {@code node} is already present
*/
@CanIgnoreReturnValue
private NetworkConnections addNodeInternal(N node) {
NetworkConnections connections = newConnections();
checkState(nodeConnections.put(node, connections) == null);
return connections;
}
@Override
@CanIgnoreReturnValue
public boolean addEdge(N nodeU, N nodeV, E edge) {
checkNotNull(nodeU, "nodeU");
checkNotNull(nodeV, "nodeV");
checkNotNull(edge, "edge");
if (containsEdge(edge)) {
EndpointPair existingIncidentNodes = incidentNodes(edge);
EndpointPair newIncidentNodes = EndpointPair.of(this, nodeU, nodeV);
checkArgument(
existingIncidentNodes.equals(newIncidentNodes),
REUSING_EDGE,
edge,
existingIncidentNodes,
newIncidentNodes);
return false;
}
NetworkConnections connectionsU = nodeConnections.get(nodeU);
if (!allowsParallelEdges()) {
checkArgument(
!(connectionsU != null && connectionsU.successors().contains(nodeV)),
PARALLEL_EDGES_NOT_ALLOWED,
nodeU,
nodeV);
}
boolean isSelfLoop = nodeU.equals(nodeV);
if (!allowsSelfLoops()) {
checkArgument(!isSelfLoop, SELF_LOOPS_NOT_ALLOWED, nodeU);
}
if (connectionsU == null) {
connectionsU = addNodeInternal(nodeU);
}
connectionsU.addOutEdge(edge, nodeV);
NetworkConnections connectionsV = nodeConnections.get(nodeV);
if (connectionsV == null) {
connectionsV = addNodeInternal(nodeV);
}
connectionsV.addInEdge(edge, nodeU, isSelfLoop);
edgeToReferenceNode.put(edge, nodeU);
return true;
}
@Override
@CanIgnoreReturnValue
public boolean removeNode(N node) {
checkNotNull(node, "node");
NetworkConnections connections = nodeConnections.get(node);
if (connections == null) {
return false;
}
// Since views are returned, we need to copy the edges that will be removed.
// Thus we avoid modifying the underlying view while iterating over it.
for (E edge : ImmutableList.copyOf(connections.incidentEdges())) {
removeEdge(edge);
}
nodeConnections.remove(node);
return true;
}
@Override
@CanIgnoreReturnValue
public boolean removeEdge(E edge) {
checkNotNull(edge, "edge");
N nodeU = edgeToReferenceNode.get(edge);
if (nodeU == null) {
return false;
}
NetworkConnections connectionsU = nodeConnections.get(nodeU);
N nodeV = connectionsU.adjacentNode(edge);
NetworkConnections connectionsV = nodeConnections.get(nodeV);
connectionsU.removeOutEdge(edge);
connectionsV.removeInEdge(edge, allowsSelfLoops() && nodeU.equals(nodeV));
edgeToReferenceNode.remove(edge);
return true;
}
private NetworkConnections newConnections() {
return isDirected()
? allowsParallelEdges()
? DirectedMultiNetworkConnections.of()
: DirectedNetworkConnections.of()
: allowsParallelEdges()
? UndirectedMultiNetworkConnections.of()
: UndirectedNetworkConnections.of();
}
}