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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including
all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and
Jakarta Messaging 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.GraphConstants.INNER_CAPACITY;
import static com.google.common.graph.GraphConstants.INNER_LOAD_FACTOR;
import static com.google.common.graph.Graphs.checkNonNegative;
import static com.google.common.graph.Graphs.checkPositive;
import com.google.common.collect.AbstractIterator;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.UnmodifiableIterator;
import java.util.AbstractSet;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.checkerframework.checker.nullness.compatqual.NullableDecl;
/**
* An implementation of {@link GraphConnections} for directed graphs.
*
* @author James Sexton
* @param Node parameter type
* @param Value parameter type
*/
final class DirectedGraphConnections implements GraphConnections {
/**
* A wrapper class to indicate a node is both a predecessor and successor while still providing
* the successor value.
*/
private static final class PredAndSucc {
private final Object successorValue;
PredAndSucc(Object successorValue) {
this.successorValue = successorValue;
}
}
private static final Object PRED = new Object();
// Every value in this map must either be an instance of PredAndSucc with a successorValue of
// type V, PRED (representing predecessor), or an instance of type V (representing successor).
private final Map adjacentNodeValues;
private int predecessorCount;
private int successorCount;
private DirectedGraphConnections(
Map adjacentNodeValues, int predecessorCount, int successorCount) {
this.adjacentNodeValues = checkNotNull(adjacentNodeValues);
this.predecessorCount = checkNonNegative(predecessorCount);
this.successorCount = checkNonNegative(successorCount);
checkState(
predecessorCount <= adjacentNodeValues.size()
&& successorCount <= adjacentNodeValues.size());
}
static DirectedGraphConnections of() {
// We store predecessors and successors in the same map, so double the initial capacity.
int initialCapacity = INNER_CAPACITY * 2;
return new DirectedGraphConnections<>(
new HashMap(initialCapacity, INNER_LOAD_FACTOR), 0, 0);
}
static DirectedGraphConnections ofImmutable(
Set predecessors, Map successorValues) {
Map adjacentNodeValues = new HashMap<>();
adjacentNodeValues.putAll(successorValues);
for (N predecessor : predecessors) {
Object value = adjacentNodeValues.put(predecessor, PRED);
if (value != null) {
adjacentNodeValues.put(predecessor, new PredAndSucc(value));
}
}
return new DirectedGraphConnections<>(
ImmutableMap.copyOf(adjacentNodeValues), predecessors.size(), successorValues.size());
}
@Override
public Set adjacentNodes() {
return Collections.unmodifiableSet(adjacentNodeValues.keySet());
}
@Override
public Set predecessors() {
return new AbstractSet() {
@Override
public UnmodifiableIterator iterator() {
final Iterator> entries = adjacentNodeValues.entrySet().iterator();
return new AbstractIterator() {
@Override
protected N computeNext() {
while (entries.hasNext()) {
Entry entry = entries.next();
if (isPredecessor(entry.getValue())) {
return entry.getKey();
}
}
return endOfData();
}
};
}
@Override
public int size() {
return predecessorCount;
}
@Override
public boolean contains(@NullableDecl Object obj) {
return isPredecessor(adjacentNodeValues.get(obj));
}
};
}
@Override
public Set successors() {
return new AbstractSet() {
@Override
public UnmodifiableIterator iterator() {
final Iterator> entries = adjacentNodeValues.entrySet().iterator();
return new AbstractIterator() {
@Override
protected N computeNext() {
while (entries.hasNext()) {
Entry entry = entries.next();
if (isSuccessor(entry.getValue())) {
return entry.getKey();
}
}
return endOfData();
}
};
}
@Override
public int size() {
return successorCount;
}
@Override
public boolean contains(@NullableDecl Object obj) {
return isSuccessor(adjacentNodeValues.get(obj));
}
};
}
@SuppressWarnings("unchecked")
@Override
public V value(N node) {
Object value = adjacentNodeValues.get(node);
if (value == PRED) {
return null;
}
if (value instanceof PredAndSucc) {
return (V) ((PredAndSucc) value).successorValue;
}
return (V) value;
}
@SuppressWarnings("unchecked")
@Override
public void removePredecessor(N node) {
Object previousValue = adjacentNodeValues.get(node);
if (previousValue == PRED) {
adjacentNodeValues.remove(node);
checkNonNegative(--predecessorCount);
} else if (previousValue instanceof PredAndSucc) {
adjacentNodeValues.put((N) node, ((PredAndSucc) previousValue).successorValue);
checkNonNegative(--predecessorCount);
}
}
@SuppressWarnings("unchecked")
@Override
public V removeSuccessor(Object node) {
Object previousValue = adjacentNodeValues.get(node);
if (previousValue == null || previousValue == PRED) {
return null;
} else if (previousValue instanceof PredAndSucc) {
adjacentNodeValues.put((N) node, PRED);
checkNonNegative(--successorCount);
return (V) ((PredAndSucc) previousValue).successorValue;
} else { // successor
adjacentNodeValues.remove(node);
checkNonNegative(--successorCount);
return (V) previousValue;
}
}
@Override
public void addPredecessor(N node, V unused) {
Object previousValue = adjacentNodeValues.put(node, PRED);
if (previousValue == null) {
checkPositive(++predecessorCount);
} else if (previousValue instanceof PredAndSucc) {
// Restore previous PredAndSucc object.
adjacentNodeValues.put(node, previousValue);
} else if (previousValue != PRED) { // successor
// Do NOT use method parameter value 'unused'. In directed graphs, successors store the value.
adjacentNodeValues.put(node, new PredAndSucc(previousValue));
checkPositive(++predecessorCount);
}
}
@SuppressWarnings("unchecked")
@Override
public V addSuccessor(N node, V value) {
Object previousValue = adjacentNodeValues.put(node, value);
if (previousValue == null) {
checkPositive(++successorCount);
return null;
} else if (previousValue instanceof PredAndSucc) {
adjacentNodeValues.put(node, new PredAndSucc(value));
return (V) ((PredAndSucc) previousValue).successorValue;
} else if (previousValue == PRED) {
adjacentNodeValues.put(node, new PredAndSucc(value));
checkPositive(++successorCount);
return null;
} else { // successor
return (V) previousValue;
}
}
private static boolean isPredecessor(@NullableDecl Object value) {
return (value == PRED) || (value instanceof PredAndSucc);
}
private static boolean isSuccessor(@NullableDecl Object value) {
return (value != PRED) && (value != null);
}
}
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