author | mchung |
Wed, 15 Feb 2017 16:18:18 -0800 | |
changeset 43873 | 705d732d3715 |
parent 42827 | 36468b5fa7f4 |
permissions | -rw-r--r-- |
38524 | 1 |
/* |
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* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package com.sun.tools.jdeps; |
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import java.io.PrintWriter; |
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import java.lang.module.ModuleDescriptor; |
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import java.lang.module.ModuleFinder; |
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import java.lang.module.ModuleReference; |
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import java.util.Collections; |
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import java.util.Deque; |
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import java.util.HashMap; |
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import java.util.HashSet; |
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import java.util.LinkedList; |
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import java.util.Map; |
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import java.util.Set; |
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import java.util.function.Consumer; |
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import java.util.function.Predicate; |
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import java.util.stream.Collectors; |
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import java.util.stream.Stream; |
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public final class Graph<T> { |
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private final Set<T> nodes; |
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private final Map<T, Set<T>> edges; |
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public Graph(Set<T> nodes, Map<T, Set<T>> edges) { |
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this.nodes = Collections.unmodifiableSet(nodes); |
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this.edges = Collections.unmodifiableMap(edges); |
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} |
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public Set<T> nodes() { |
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return nodes; |
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} |
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public Map<T, Set<T>> edges() { |
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return edges; |
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} |
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public Set<T> adjacentNodes(T u) { |
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return edges.get(u); |
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} |
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public boolean contains(T u) { |
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return nodes.contains(u); |
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} |
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public Set<Edge<T>> edgesFrom(T u) { |
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return edges.get(u).stream() |
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.map(v -> new Edge<T>(u, v)) |
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.collect(Collectors.toSet()); |
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} |
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/** |
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* Returns a new Graph after transitive reduction |
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*/ |
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public Graph<T> reduce() { |
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Builder<T> builder = new Builder<>(); |
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nodes.stream() |
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.forEach(u -> { |
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builder.addNode(u); |
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edges.get(u).stream() |
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.filter(v -> !pathExists(u, v, false)) |
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.forEach(v -> builder.addEdge(u, v)); |
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}); |
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return builder.build(); |
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} |
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/** |
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* Returns a new Graph after transitive reduction. All edges in |
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* the given g takes precedence over this graph. |
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* |
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* @throw IllegalArgumentException g must be a subgraph this graph |
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*/ |
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public Graph<T> reduce(Graph<T> g) { |
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boolean subgraph = nodes.containsAll(g.nodes) && |
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g.edges.keySet().stream() |
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.allMatch(u -> adjacentNodes(u).containsAll(g.adjacentNodes(u))); |
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if (!subgraph) { |
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throw new IllegalArgumentException(g + " is not a subgraph of " + this); |
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} |
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Builder<T> builder = new Builder<>(); |
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nodes.stream() |
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.forEach(u -> { |
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builder.addNode(u); |
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// filter the edge if there exists a path from u to v in the given g |
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// or there exists another path from u to v in this graph |
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edges.get(u).stream() |
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.filter(v -> !g.pathExists(u, v) && !pathExists(u, v, false)) |
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.forEach(v -> builder.addEdge(u, v)); |
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}); |
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// add the overlapped edges from this graph and the given g |
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g.edges().keySet().stream() |
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.forEach(u -> g.adjacentNodes(u).stream() |
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.filter(v -> isAdjacent(u, v)) |
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.forEach(v -> builder.addEdge(u, v))); |
|
43873
705d732d3715
8173374: Update GenGraphs tool to generate dot graph with requires transitive edges
mchung
parents:
42827
diff
changeset
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return builder.build().reduce(); |
38524 | 120 |
} |
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/** |
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* Returns nodes sorted in topological order. |
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*/ |
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public Stream<T> orderedNodes() { |
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TopoSorter<T> sorter = new TopoSorter<>(this); |
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return sorter.result.stream(); |
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} |
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/** |
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* Traverse this graph and performs the given action in topological order |
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*/ |
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public void ordered(Consumer<T> action) { |
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TopoSorter<T> sorter = new TopoSorter<>(this); |
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sorter.ordered(action); |
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} |
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/** |
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* Traverses this graph and performs the given action in reverse topological order |
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*/ |
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public void reverse(Consumer<T> action) { |
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TopoSorter<T> sorter = new TopoSorter<>(this); |
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sorter.reverse(action); |
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} |
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/** |
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* Returns a transposed graph from this graph |
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*/ |
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public Graph<T> transpose() { |
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Builder<T> builder = new Builder<>(); |
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builder.addNodes(nodes); |
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// reverse edges |
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edges.keySet().forEach(u -> { |
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edges.get(u).stream() |
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.forEach(v -> builder.addEdge(v, u)); |
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}); |
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return builder.build(); |
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} |
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/** |
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* Returns all nodes reachable from the given set of roots. |
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*/ |
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public Set<T> dfs(Set<T> roots) { |
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Deque<T> deque = new LinkedList<>(roots); |
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Set<T> visited = new HashSet<>(); |
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while (!deque.isEmpty()) { |
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T u = deque.pop(); |
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if (!visited.contains(u)) { |
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visited.add(u); |
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if (contains(u)) { |
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adjacentNodes(u).stream() |
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.filter(v -> !visited.contains(v)) |
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.forEach(deque::push); |
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} |
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} |
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} |
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return visited; |
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} |
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private boolean isAdjacent(T u, T v) { |
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return edges.containsKey(u) && edges.get(u).contains(v); |
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} |
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private boolean pathExists(T u, T v) { |
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return pathExists(u, v, true); |
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} |
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/** |
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* Returns true if there exists a path from u to v in this graph. |
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* If includeAdjacent is false, it returns true if there exists |
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* another path from u to v of distance > 1 |
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*/ |
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private boolean pathExists(T u, T v, boolean includeAdjacent) { |
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if (!nodes.contains(u) || !nodes.contains(v)) { |
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return false; |
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} |
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if (includeAdjacent && isAdjacent(u, v)) { |
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return true; |
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} |
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Deque<T> stack = new LinkedList<>(); |
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Set<T> visited = new HashSet<>(); |
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stack.push(u); |
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while (!stack.isEmpty()) { |
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T node = stack.pop(); |
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if (node.equals(v)) { |
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return true; |
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} |
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if (!visited.contains(node)) { |
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visited.add(node); |
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edges.get(node).stream() |
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.filter(e -> includeAdjacent || !node.equals(u) || !e.equals(v)) |
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42827
36468b5fa7f4
8181370: Convert anonymous inner classes into lambdas/method references
mcimadamore
parents:
42407
diff
changeset
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.forEach(stack::push); |
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} |
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} |
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assert !visited.contains(v); |
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return false; |
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} |
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public void printGraph(PrintWriter out) { |
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out.println("graph for " + nodes); |
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nodes.stream() |
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.forEach(u -> adjacentNodes(u).stream() |
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.forEach(v -> out.format(" %s -> %s%n", u, v))); |
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} |
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@Override |
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public String toString() { |
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return nodes.toString(); |
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} |
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static class Edge<T> { |
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final T u; |
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final T v; |
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Edge(T u, T v) { |
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this.u = u; |
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this.v = v; |
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} |
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@Override |
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public String toString() { |
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return String.format("%s -> %s", u, v); |
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} |
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@Override |
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public boolean equals(Object o) { |
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if (this == o) return true; |
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if (o == null || !(o instanceof Edge)) |
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return false; |
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@SuppressWarnings("unchecked") |
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Edge<T> edge = (Edge<T>) o; |
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return u.equals(edge.u) && v.equals(edge.v); |
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} |
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@Override |
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public int hashCode() { |
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int result = u.hashCode(); |
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result = 31 * result + v.hashCode(); |
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return result; |
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} |
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} |
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static class Builder<T> { |
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final Set<T> nodes = new HashSet<>(); |
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final Map<T, Set<T>> edges = new HashMap<>(); |
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public void addNode(T node) { |
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if (nodes.contains(node)) { |
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return; |
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} |
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nodes.add(node); |
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edges.computeIfAbsent(node, _e -> new HashSet<>()); |
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} |
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public void addNodes(Set<T> nodes) { |
|
43873
705d732d3715
8173374: Update GenGraphs tool to generate dot graph with requires transitive edges
mchung
parents:
42827
diff
changeset
|
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this.nodes.addAll(nodes); |
38524 | 278 |
} |
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public void addEdge(T u, T v) { |
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addNode(u); |
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addNode(v); |
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edges.get(u).add(v); |
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} |
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public Graph<T> build() { |
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return new Graph<T>(nodes, edges); |
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} |
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} |
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/** |
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* Topological sort |
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*/ |
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static class TopoSorter<T> { |
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final Deque<T> result = new LinkedList<>(); |
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final Deque<T> nodes; |
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final Graph<T> graph; |
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TopoSorter(Graph<T> graph) { |
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this.graph = graph; |
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this.nodes = new LinkedList<>(graph.nodes); |
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sort(); |
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} |
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public void ordered(Consumer<T> action) { |
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result.iterator().forEachRemaining(action); |
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} |
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public void reverse(Consumer<T> action) { |
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result.descendingIterator().forEachRemaining(action); |
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} |
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private void sort() { |
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Deque<T> visited = new LinkedList<>(); |
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Deque<T> done = new LinkedList<>(); |
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T node; |
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while ((node = nodes.poll()) != null) { |
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if (!visited.contains(node)) { |
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visit(node, visited, done); |
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} |
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} |
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} |
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private void visit(T node, Deque<T> visited, Deque<T> done) { |
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if (visited.contains(node)) { |
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if (!done.contains(node)) { |
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throw new IllegalArgumentException("Cyclic detected: " + |
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node + " " + graph.edges().get(node)); |
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} |
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return; |
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} |
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visited.add(node); |
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graph.edges().get(node).stream() |
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.forEach(x -> visit(x, visited, done)); |
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done.add(node); |
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result.addLast(node); |
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} |
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} |
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} |